diff --git a/adb/Android.bp b/adb/Android.bp
index ae8e386..6234af1 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -24,7 +24,7 @@
         "-Wno-missing-field-initializers",
         "-Wvla",
     ],
-    rtti: true,
+    cpp_std: "experimental",
 
     use_version_lib: true,
 
diff --git a/adb/adb.h b/adb/adb.h
index e2911e8..cdd6346 100644
--- a/adb/adb.h
+++ b/adb/adb.h
@@ -149,6 +149,10 @@
 #endif
 
 #if !ADB_HOST
+asocket* daemon_service_to_socket(std::string_view name);
+#endif
+
+#if !ADB_HOST
 int init_jdwp(void);
 asocket* create_jdwp_service_socket();
 asocket* create_jdwp_tracker_service_socket();
diff --git a/adb/client/adb_install.cpp b/adb/client/adb_install.cpp
index 079a975..054cbac 100644
--- a/adb/client/adb_install.cpp
+++ b/adb/client/adb_install.cpp
@@ -331,11 +331,6 @@
         error_exit("Attempting to use streaming install on unsupported device");
     }
 
-    if (use_fastdeploy == true && is_reinstall == false) {
-        printf("Fast Deploy is only available with -r.\n");
-        use_fastdeploy = false;
-    }
-
     if (use_fastdeploy == true && get_device_api_level() < kFastDeployMinApi) {
         printf("Fast Deploy is only compatible with devices of API version %d or higher, "
                "ignoring.\n",
@@ -350,10 +345,17 @@
             passthrough_argv.push_back(argv[i]);
         }
     }
+    if (passthrough_argv.size() < 2) {
+        error_exit("install requires an apk argument");
+    }
 
     if (use_fastdeploy == true) {
         fastdeploy_set_local_agent(use_localagent);
         update_agent(agent_update_strategy);
+
+        // The last argument must be the APK file
+        const char* file = passthrough_argv.back();
+        use_fastdeploy = find_package(file);
     }
 
     switch (installMode) {
diff --git a/adb/client/commandline.cpp b/adb/client/commandline.cpp
index 95e66ae..8676214 100644
--- a/adb/client/commandline.cpp
+++ b/adb/client/commandline.cpp
@@ -154,8 +154,8 @@
         "     --instant: cause the app to be installed as an ephemeral install app\n"
         "     --no-streaming: always push APK to device and invoke Package Manager as separate steps\n"
         "     --streaming: force streaming APK directly into Package Manager\n"
-        "     --fastdeploy: use fast deploy (only valid with -r)\n"
-        "     --no-fastdeploy: prevent use of fast deploy (only valid with -r)\n"
+        "     --fastdeploy: use fast deploy\n"
+        "     --no-fastdeploy: prevent use of fast deploy\n"
         "     --force-agent: force update of deployment agent when using fast deploy\n"
         "     --date-check-agent: update deployment agent when local version is newer and using fast deploy\n"
         "     --version-check-agent: update deployment agent when local version has different version code and using fast deploy\n"
@@ -1275,6 +1275,42 @@
     return 0;
 }
 
+static int adb_connect_command_bidirectional(const std::string& command) {
+    std::string error;
+    int fd = adb_connect(command, &error);
+    if (fd < 0) {
+        fprintf(stderr, "error: %s\n", error.c_str());
+        return 1;
+    }
+
+    static constexpr auto forward = [](int src, int sink, bool exit_on_end) {
+        char buf[4096];
+        while (true) {
+            int rc = adb_read(src, buf, sizeof(buf));
+            if (rc == 0) {
+                if (exit_on_end) {
+                    exit(0);
+                } else {
+                    adb_shutdown(sink, SHUT_WR);
+                }
+                return;
+            } else if (rc < 0) {
+                perror_exit("read failed");
+            }
+            if (!WriteFdExactly(sink, buf, rc)) {
+                perror_exit("write failed");
+            }
+        }
+    };
+
+    std::thread read(forward, fd, STDOUT_FILENO, true);
+    std::thread write(forward, STDIN_FILENO, fd, false);
+    read.join();
+    write.join();
+    adb_close(fd);
+    return 0;
+}
+
 static int adb_query_command(const std::string& command) {
     std::string result;
     std::string error;
@@ -1766,7 +1802,7 @@
         if (argc != 2) {
             error_exit("usage: adb raw SERVICE");
         }
-        return adb_connect_command(argv[1]);
+        return adb_connect_command_bidirectional(argv[1]);
     }
 
     /* "adb /?" is a common idiom under Windows */
diff --git a/adb/client/fastdeploy.cpp b/adb/client/fastdeploy.cpp
index e82f15a..f4e8664 100644
--- a/adb/client/fastdeploy.cpp
+++ b/adb/client/fastdeploy.cpp
@@ -16,6 +16,7 @@
 
 #include "fastdeploy.h"
 
+#include <string.h>
 #include <algorithm>
 #include <array>
 #include <memory>
@@ -31,7 +32,7 @@
 
 #include "adb_utils.h"
 
-static constexpr long kRequiredAgentVersion = 0x00000001;
+static constexpr long kRequiredAgentVersion = 0x00000002;
 
 static constexpr const char* kDeviceAgentPath = "/data/local/tmp/";
 
@@ -313,9 +314,16 @@
     std::vector<unsigned char> applyErrorBuffer;
     std::string argsString;
 
+    bool rSwitchPresent = false;
     for (int i = 0; i < argc; i++) {
         argsString.append(argv[i]);
         argsString.append(" ");
+        if (!strcmp(argv[i], "-r")) {
+            rSwitchPresent = true;
+        }
+    }
+    if (!rSwitchPresent) {
+        argsString.append("-r");
     }
 
     std::string applyPatchCommand =
@@ -326,3 +334,9 @@
         error_exit("Executing %s returned %d", applyPatchCommand.c_str(), returnCode);
     }
 }
+
+bool find_package(const char* apkPath) {
+    const std::string findCommand =
+            "/data/local/tmp/deployagent find " + get_packagename_from_apk(apkPath);
+    return !send_shell_command(findCommand);
+}
diff --git a/adb/client/fastdeploy.h b/adb/client/fastdeploy.h
index a6b10d3..7b7f2ec 100644
--- a/adb/client/fastdeploy.h
+++ b/adb/client/fastdeploy.h
@@ -32,3 +32,4 @@
 void apply_patch_on_device(const char* apkPath, const char* patchPath, const char* outputPath);
 void install_patch(const char* apkPath, const char* patchPath, int argc, const char** argv);
 std::string get_patch_path(const char* apkPath);
+bool find_package(const char* apkPath);
diff --git a/adb/daemon/remount_service.cpp b/adb/daemon/remount_service.cpp
index b72ed16..1a92317 100644
--- a/adb/daemon/remount_service.cpp
+++ b/adb/daemon/remount_service.cpp
@@ -245,9 +245,8 @@
     // If we can use overlayfs, lets get it in place first
     // before we struggle with determining deduplication operations.
     if (!verity_enabled && fs_mgr_overlayfs_setup()) {
-        std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
-                                                                   fs_mgr_free_fstab);
-        if (fs_mgr_overlayfs_mount_all(fstab.get())) {
+        Fstab fstab;
+        if (ReadDefaultFstab(&fstab) && fs_mgr_overlayfs_mount_all(&fstab)) {
             WriteFdExactly(fd.get(), "overlayfs mounted\n");
         }
     }
diff --git a/adb/daemon/services.cpp b/adb/daemon/services.cpp
index b300fac..3182ddd 100644
--- a/adb/daemon/services.cpp
+++ b/adb/daemon/services.cpp
@@ -33,6 +33,7 @@
 #include <thread>
 
 #include <android-base/file.h>
+#include <android-base/parseint.h>
 #include <android-base/parsenetaddress.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
@@ -223,6 +224,105 @@
     WriteFdExactly(fd.get(), "spinning\n");
 }
 
+struct ServiceSocket : public asocket {
+    ServiceSocket() {
+        install_local_socket(this);
+        this->enqueue = [](asocket* self, apacket::payload_type data) {
+            return static_cast<ServiceSocket*>(self)->Enqueue(std::move(data));
+        };
+        this->ready = [](asocket* self) { return static_cast<ServiceSocket*>(self)->Ready(); };
+        this->close = [](asocket* self) { return static_cast<ServiceSocket*>(self)->Close(); };
+    }
+    virtual ~ServiceSocket() = default;
+
+    virtual int Enqueue(apacket::payload_type data) { return -1; }
+    virtual void Ready() {}
+    virtual void Close() {
+        if (peer) {
+            peer->peer = nullptr;
+            if (peer->shutdown) {
+                peer->shutdown(peer);
+            }
+            peer->close(peer);
+        }
+
+        remove_socket(this);
+        delete this;
+    }
+};
+
+struct SinkSocket : public ServiceSocket {
+    explicit SinkSocket(size_t byte_count) {
+        LOG(INFO) << "Creating new SinkSocket with capacity " << byte_count;
+        bytes_left_ = byte_count;
+    }
+
+    virtual ~SinkSocket() { LOG(INFO) << "SinkSocket destroyed"; }
+
+    virtual int Enqueue(apacket::payload_type data) override final {
+        if (bytes_left_ <= data.size()) {
+            // Done reading.
+            Close();
+            return -1;
+        }
+
+        bytes_left_ -= data.size();
+        return 0;
+    }
+
+    size_t bytes_left_;
+};
+
+struct SourceSocket : public ServiceSocket {
+    explicit SourceSocket(size_t byte_count) {
+        LOG(INFO) << "Creating new SourceSocket with capacity " << byte_count;
+        bytes_left_ = byte_count;
+    }
+
+    virtual ~SourceSocket() { LOG(INFO) << "SourceSocket destroyed"; }
+
+    void Ready() {
+        size_t len = std::min(bytes_left_, get_max_payload());
+        if (len == 0) {
+            Close();
+            return;
+        }
+
+        Block block(len);
+        memset(block.data(), 0, block.size());
+        peer->enqueue(peer, std::move(block));
+        bytes_left_ -= len;
+    }
+
+    int Enqueue(apacket::payload_type data) { return -1; }
+
+    size_t bytes_left_;
+};
+
+asocket* daemon_service_to_socket(std::string_view name) {
+    if (name == "jdwp") {
+        return create_jdwp_service_socket();
+    } else if (name == "track-jdwp") {
+        return create_jdwp_tracker_service_socket();
+    } else if (name.starts_with("sink:")) {
+        name.remove_prefix(strlen("sink:"));
+        uint64_t byte_count = 0;
+        if (!android::base::ParseUint(name.data(), &byte_count)) {
+            return nullptr;
+        }
+        return new SinkSocket(byte_count);
+    } else if (name.starts_with("source:")) {
+        name.remove_prefix(strlen("source:"));
+        uint64_t byte_count = 0;
+        if (!android::base::ParseUint(name.data(), &byte_count)) {
+            return nullptr;
+        }
+        return new SourceSocket(byte_count);
+    }
+
+    return nullptr;
+}
+
 unique_fd daemon_service_to_fd(const char* name, atransport* transport) {
     if (!strncmp("dev:", name, 4)) {
         return unique_fd{unix_open(name + 4, O_RDWR | O_CLOEXEC)};
diff --git a/adb/daemon/shell_service.cpp b/adb/daemon/shell_service.cpp
index 01097ac..8805fc1 100644
--- a/adb/daemon/shell_service.cpp
+++ b/adb/daemon/shell_service.cpp
@@ -273,7 +273,7 @@
     }
 
     std::vector<std::string> joined_env;
-    for (auto it : env) {
+    for (const auto& it : env) {
         const char* key = it.first.c_str();
         const char* value = it.second.c_str();
         joined_env.push_back(android::base::StringPrintf("%s=%s", key, value));
diff --git a/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java b/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
index 17845e2..2d3b135 100644
--- a/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
+++ b/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
@@ -35,7 +35,7 @@
 
 public final class DeployAgent {
     private static final int BUFFER_SIZE = 128 * 1024;
-    private static final int AGENT_VERSION = 0x00000001;
+    private static final int AGENT_VERSION = 0x00000002;
 
     public static void main(String[] args) {
         int exitCode = 0;
@@ -53,6 +53,15 @@
 
                 String packageName = args[1];
                 extractMetaData(packageName);
+            } else if (commandString.equals("find")) {
+                if (args.length != 2) {
+                    showUsage(1);
+                }
+
+                String packageName = args[1];
+                if (getFilenameFromPackageName(packageName) == null) {
+                    exitCode = 3;
+                }
             } else if (commandString.equals("apply")) {
                 if (args.length < 4) {
                     showUsage(1);
@@ -112,6 +121,7 @@
             "usage: deployagent <command> [<args>]\n\n" +
             "commands:\n" +
             "version                             get the version\n" +
+            "find PKGNAME                        return zero if package found, else non-zero\n" +
             "extract PKGNAME                     extract an installed package's metadata\n" +
             "apply PKGNAME PATCHFILE [-o|-pm]    apply a patch from PATCHFILE (- for stdin) to an installed package\n" +
             " -o <FILE> directs output to FILE, default or - for stdout\n" +
@@ -134,7 +144,7 @@
         return null;
     }
 
-    private static File getFileFromPackageName(String packageName) throws IOException {
+    private static String getFilenameFromPackageName(String packageName) throws IOException {
         StringBuilder commandBuilder = new StringBuilder();
         commandBuilder.append("pm list packages -f " + packageName);
 
@@ -153,10 +163,19 @@
                 int equalsIndex = line.lastIndexOf(packageSuffix);
                 String fileName =
                     line.substring(packageIndex + packagePrefix.length(), equalsIndex);
-                return new File(fileName);
+                return fileName;
             }
         }
-        throw new IOException("package not found");
+        return null;
+    }
+
+    private static File getFileFromPackageName(String packageName) throws IOException {
+        String filename = getFilenameFromPackageName(packageName);
+        if (filename == null) {
+            // Should not happen (function is only called when we know the package exists)
+            throw new IOException("package not found");
+        }
+        return new File(filename);
     }
 
     private static void extractMetaData(String packageName) throws IOException {
diff --git a/adb/sockets.cpp b/adb/sockets.cpp
index 8b07f74..1bd57c1 100644
--- a/adb/sockets.cpp
+++ b/adb/sockets.cpp
@@ -348,11 +348,8 @@
 
 asocket* create_local_service_socket(const char* name, atransport* transport) {
 #if !ADB_HOST
-    if (!strcmp(name, "jdwp")) {
-        return create_jdwp_service_socket();
-    }
-    if (!strcmp(name, "track-jdwp")) {
-        return create_jdwp_tracker_service_socket();
+    if (asocket* s = daemon_service_to_socket(name); s) {
+        return s;
     }
 #endif
     int fd = service_to_fd(name, transport);
diff --git a/adb/transport.cpp b/adb/transport.cpp
index 8741654..f59a135 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -1305,11 +1305,7 @@
 void unregister_usb_transport(usb_handle* usb) {
     std::lock_guard<std::recursive_mutex> lock(transport_lock);
     transport_list.remove_if([usb](atransport* t) {
-        auto connection = t->connection();
-        if (auto usb_connection = dynamic_cast<UsbConnection*>(connection.get())) {
-            return usb_connection->handle_ == usb && t->GetConnectionState() == kCsNoPerm;
-        }
-        return false;
+        return t->GetUsbHandle() == usb && t->GetConnectionState() == kCsNoPerm;
     });
 }
 #endif
diff --git a/adb/transport.h b/adb/transport.h
index d593700..790004f 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -37,6 +37,7 @@
 
 #include "adb.h"
 #include "adb_unique_fd.h"
+#include "usb.h"
 
 typedef std::unordered_set<std::string> FeatureSet;
 
@@ -242,6 +243,9 @@
         return connection_;
     }
 
+    void SetUsbHandle(usb_handle* h) { usb_handle_ = h; }
+    usb_handle* GetUsbHandle() { return usb_handle_; }
+
     const TransportId id;
     size_t ref_count = 0;
     bool online = false;
@@ -333,6 +337,9 @@
     // The underlying connection object.
     std::shared_ptr<Connection> connection_ GUARDED_BY(mutex_);
 
+    // USB handle for the connection, if available.
+    usb_handle* usb_handle_ = nullptr;
+
     // A callback that will be invoked when the atransport needs to reconnect.
     ReconnectCallback reconnect_;
 
diff --git a/adb/transport_usb.cpp b/adb/transport_usb.cpp
index c471bf9..2e5918a 100644
--- a/adb/transport_usb.cpp
+++ b/adb/transport_usb.cpp
@@ -180,6 +180,7 @@
     auto connection = std::make_unique<UsbConnection>(h);
     t->SetConnection(std::make_unique<BlockingConnectionAdapter>(std::move(connection)));
     t->type = kTransportUsb;
+    t->SetUsbHandle(h);
 }
 
 int is_adb_interface(int usb_class, int usb_subclass, int usb_protocol) {
diff --git a/base/Android.bp b/base/Android.bp
index 741664b..b0181aa 100644
--- a/base/Android.bp
+++ b/base/Android.bp
@@ -20,6 +20,7 @@
         "-Wall",
         "-Werror",
         "-Wextra",
+        "-D_FILE_OFFSET_BITS=64",
     ],
 }
 
diff --git a/debuggerd/Android.bp b/debuggerd/Android.bp
index d9fae52..5167481 100644
--- a/debuggerd/Android.bp
+++ b/debuggerd/Android.bp
@@ -116,14 +116,21 @@
         "libdebuggerd",
         "libbacktrace",
         "libunwindstack",
-        "libdexfile",
+        "libdexfile",  // libunwindstack dependency
+        "libdexfile_external",  // libunwindstack dependency
+        "libdexfile_support",  // libunwindstack dependency
         "liblzma",
         "libcutils",
     ],
     target: {
         recovery: {
             cflags: ["-DNO_LIBDEXFILE_SUPPORT"],
-            exclude_static_libs: ["libdexfile"],
+            exclude_static_libs: [
+                "libartbase",
+                "libdexfile",
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
         },
     },
 
@@ -170,12 +177,22 @@
 
     static_libs: [
         "libbacktrace",
+        "libdexfile_external",  // libunwindstack dependency
+        "libdexfile_support",  // libunwindstack dependency
         "libunwindstack",
         "liblzma",
         "libbase",
         "libcutils",
         "liblog",
     ],
+    target: {
+        recovery: {
+            exclude_static_libs: [
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
+        },
+    },
 }
 
 cc_test {
@@ -216,6 +233,8 @@
 
     static_libs: [
         "libdebuggerd",
+        "libdexfile_external",  // libunwindstack dependency
+        "libdexfile_support",  // libunwindstack dependency
         "libunwindstack",
     ],
 
diff --git a/debuggerd/libdebuggerd/test/tombstone_test.cpp b/debuggerd/libdebuggerd/test/tombstone_test.cpp
index 421ce43..d24c887 100644
--- a/debuggerd/libdebuggerd/test/tombstone_test.cpp
+++ b/debuggerd/libdebuggerd/test/tombstone_test.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdlib.h>
+#include <time.h>
 
 #include <memory>
 #include <string>
@@ -494,3 +495,10 @@
   expected += android::base::StringPrintf("ABI: '%s'\n", ABI_STRING);
   ASSERT_STREQ(expected.c_str(), amfd_data_.c_str());
 }
+
+TEST_F(TombstoneTest, dump_timestamp) {
+  setenv("TZ", "UTC", 1);
+  tzset();
+  dump_timestamp(&log_, 0);
+  ASSERT_STREQ("Timestamp: 1970-01-01 00:00:00+0000\n", amfd_data_.c_str());
+}
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 1179263..b20014f 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -78,6 +78,15 @@
   _LOG(log, logtype::HEADER, "ABI: '%s'\n", ABI_STRING);
 }
 
+static void dump_timestamp(log_t* log, time_t time) {
+  struct tm tm;
+  localtime_r(&time, &tm);
+
+  char buf[strlen("1970-01-01 00:00:00+0830") + 1];
+  strftime(buf, sizeof(buf), "%F %T%z", &tm);
+  _LOG(log, logtype::HEADER, "Timestamp: %s\n", buf);
+}
+
 static void dump_probable_cause(log_t* log, const siginfo_t* si, BacktraceMap* map) {
   std::string cause;
   if (si->si_signo == SIGSEGV && si->si_code == SEGV_MAPERR) {
@@ -654,6 +663,7 @@
 
   _LOG(&log, logtype::HEADER, "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
   dump_header_info(&log);
+  dump_timestamp(&log, time(nullptr));
 
   auto it = threads.find(target_thread);
   if (it == threads.end()) {
diff --git a/fastboot/device/commands.cpp b/fastboot/device/commands.cpp
index 71d2a1d..e91598d 100644
--- a/fastboot/device/commands.cpp
+++ b/fastboot/device/commands.cpp
@@ -329,12 +329,14 @@
     MetadataBuilder* operator->() const { return builder_.get(); }
 
   private:
+    FastbootDevice* device_;
     std::string super_device_;
     uint32_t slot_number_;
     std::unique_ptr<MetadataBuilder> builder_;
 };
 
-PartitionBuilder::PartitionBuilder(FastbootDevice* device, const std::string& partition_name) {
+PartitionBuilder::PartitionBuilder(FastbootDevice* device, const std::string& partition_name)
+    : device_(device) {
     std::string slot_suffix = GetSuperSlotSuffix(device, partition_name);
     slot_number_ = SlotNumberForSlotSuffix(slot_suffix);
     auto super_device = FindPhysicalPartition(fs_mgr_get_super_partition_name(slot_number_));
@@ -350,7 +352,7 @@
     if (!metadata) {
         return false;
     }
-    return UpdateAllPartitionMetadata(super_device_, *metadata.get());
+    return UpdateAllPartitionMetadata(device_, super_device_, *metadata.get());
 }
 
 bool CreatePartitionHandler(FastbootDevice* device, const std::vector<std::string>& args) {
diff --git a/fastboot/device/flashing.cpp b/fastboot/device/flashing.cpp
index fbba631..963916c 100644
--- a/fastboot/device/flashing.cpp
+++ b/fastboot/device/flashing.cpp
@@ -184,7 +184,7 @@
     }
 
     // Write the new table to every metadata slot.
-    if (!UpdateAllPartitionMetadata(super_name, *new_metadata.get())) {
+    if (!UpdateAllPartitionMetadata(device, super_name, *new_metadata.get())) {
         return device->WriteFail("Unable to write new partition table");
     }
     fs_mgr_overlayfs_teardown();
diff --git a/fastboot/device/utility.cpp b/fastboot/device/utility.cpp
index 2ae9ac5..2ebd57d 100644
--- a/fastboot/device/utility.cpp
+++ b/fastboot/device/utility.cpp
@@ -200,10 +200,16 @@
     return cmdline.find("androidboot.verifiedbootstate=orange") == std::string::npos;
 }
 
-bool UpdateAllPartitionMetadata(const std::string& super_name,
+bool UpdateAllPartitionMetadata(FastbootDevice* device, const std::string& super_name,
                                 const android::fs_mgr::LpMetadata& metadata) {
+    size_t num_slots = 1;
+    auto boot_control_hal = device->boot_control_hal();
+    if (boot_control_hal) {
+        num_slots = boot_control_hal->getNumberSlots();
+    }
+
     bool ok = true;
-    for (size_t i = 0; i < metadata.geometry.metadata_slot_count; i++) {
+    for (size_t i = 0; i < num_slots; i++) {
         ok &= UpdatePartitionTable(super_name, metadata, i);
     }
     return ok;
diff --git a/fastboot/device/utility.h b/fastboot/device/utility.h
index 4c6aa07..bfeeb74 100644
--- a/fastboot/device/utility.h
+++ b/fastboot/device/utility.h
@@ -68,5 +68,5 @@
 bool GetDeviceLockStatus();
 
 // Update all copies of metadata.
-bool UpdateAllPartitionMetadata(const std::string& super_name,
+bool UpdateAllPartitionMetadata(FastbootDevice* device, const std::string& super_name,
                                 const android::fs_mgr::LpMetadata& metadata);
diff --git a/fastboot/fuzzy_fastboot/main.cpp b/fastboot/fuzzy_fastboot/main.cpp
index 479a06a..ef34771 100644
--- a/fastboot/fuzzy_fastboot/main.cpp
+++ b/fastboot/fuzzy_fastboot/main.cpp
@@ -281,7 +281,7 @@
     std::vector<std::string> vars;
     EXPECT_EQ(fb->GetVarAll(&vars), SUCCESS) << "getvar:all failed";
     EXPECT_GT(vars.size(), 0) << "getvar:all did not respond with any INFO responses";
-    for (const auto s : vars) {
+    for (const auto& s : vars) {
         EXPECT_LE(s.size(), FB_RESPONSE_SZ - 4)
                 << "getvar:all included an INFO response: 'INFO" + s << "' which is too long";
     }
@@ -316,7 +316,7 @@
     EXPECT_GT(parts.size(), 0)
             << "getvar:all did not report any partition-size: through INFO responses";
     std::set<std::string> allowed{"ext4", "f2fs", "raw"};
-    for (const auto p : parts) {
+    for (const auto& p : parts) {
         EXPECT_GE(std::get<1>(p), 0);
         std::string part(std::get<0>(p));
         std::set<std::string> allowed{"ext4", "f2fs", "raw"};
@@ -355,7 +355,7 @@
     if (num_slots > 0) {
         EXPECT_EQ(fb->GetVar("current-slot", &var), SUCCESS) << "getvar:current-slot failed";
 
-        for (const auto p : parts) {
+        for (const auto& p : parts) {
             std::string part(std::get<0>(p));
             std::regex reg("([[:graph:]]*)_([[:lower:]])");
             std::smatch sm;
@@ -378,7 +378,7 @@
             }
         }
         // Ensure each partition has the correct slot suffix
-        for (const auto iter : part_slots) {
+        for (const auto& iter : part_slots) {
             const std::set<char>& char_set = iter.second;
             std::string chars;
             for (char c : char_set) {
@@ -572,7 +572,7 @@
     std::vector<std::tuple<std::string, uint64_t>> parts;
     EXPECT_EQ(fb->Partitions(&parts), SUCCESS) << "getvar:all failed in locked mode";
     std::string resp;
-    for (const auto tup : parts) {
+    for (const auto& tup : parts) {
         EXPECT_EQ(fb->Flash(std::get<0>(tup), &resp), DEVICE_FAIL)
                 << "Device did not respond with FAIL when trying to flash '" << std::get<0>(tup)
                 << "' in locked mode";
@@ -585,7 +585,7 @@
     std::vector<std::tuple<std::string, uint64_t>> parts;
     EXPECT_EQ(fb->Partitions(&parts), SUCCESS) << "getvar:all failed";
     std::string resp;
-    for (const auto tup : parts) {
+    for (const auto& tup : parts) {
         EXPECT_EQ(fb->Erase(std::get<0>(tup), &resp), DEVICE_FAIL)
                 << "Device did not respond with FAIL when trying to erase '" << std::get<0>(tup)
                 << "' in locked mode";
@@ -601,7 +601,7 @@
     EXPECT_EQ(fb->GetVar("slot-count", &resp), SUCCESS) << "getvar:slot-count failed";
     int32_t num_slots = strtol(resp.c_str(), nullptr, 10);
 
-    for (const auto tup : parts) {
+    for (const auto& tup : parts) {
         std::string part(std::get<0>(tup));
         std::regex reg("([[:graph:]]*)_([[:lower:]])");
         std::smatch sm;
@@ -1554,12 +1554,12 @@
 
 void GenerateXmlTests(const extension::Configuration& config) {
     // Build the getvar tests
-    for (const auto it : config.getvars) {
+    for (const auto& it : config.getvars) {
         GETVAR_XML_TESTS.push_back(std::make_pair(it.first, it.second));
     }
 
     // Build the partition tests, to interface with gtest we need to do it this way
-    for (const auto it : config.partitions) {
+    for (const auto& it : config.partitions) {
         const auto tup = std::make_tuple(it.first, it.second);
         PARTITION_XML_TESTS.push_back(tup);  // All partitions
 
@@ -1581,7 +1581,7 @@
 
     // Build the packed tests, only useful if we have a hash
     if (!config.checksum.empty()) {
-        for (const auto it : config.packed) {
+        for (const auto& it : config.packed) {
             for (const auto& test : it.second.tests) {
                 const auto tup = std::make_tuple(it.first, test);
                 if (test.expect == extension::OKAY) {  // only testing the success case
@@ -1608,7 +1608,7 @@
     }
 
     // Build oem tests
-    for (const auto it : config.oem) {
+    for (const auto& it : config.oem) {
         auto oem_cmd = it.second;
         for (const auto& t : oem_cmd.tests) {
             OEM_XML_TESTS.push_back(std::make_tuple(it.first, oem_cmd.restricted, t));
diff --git a/fs_mgr/Android.bp b/fs_mgr/Android.bp
index 99231ac..824511e 100644
--- a/fs_mgr/Android.bp
+++ b/fs_mgr/Android.bp
@@ -23,7 +23,6 @@
     cflags: [
         "-Wall",
         "-Werror",
-        "-Wno-unused-variable",
     ],
 }
 
@@ -41,6 +40,7 @@
         "fs_mgr_verity.cpp",
         "fs_mgr_dm_linear.cpp",
         "fs_mgr_overlayfs.cpp",
+        "fs_mgr_roots.cpp",
         "fs_mgr_vendor_overlay.cpp",
     ],
     shared_libs: [
diff --git a/fs_mgr/README.overlayfs.md b/fs_mgr/README.overlayfs.md
index fbb5f5d..960410c 100644
--- a/fs_mgr/README.overlayfs.md
+++ b/fs_mgr/README.overlayfs.md
@@ -83,18 +83,19 @@
 -------
 
 - Space used in the backing storage is on a file by file basis
-  and will require more space than if updated in place.
+  and will require more space than if updated in place.  As such
+  it is important to be mindful of any wasted space, for instance
+  **BOARD_<partition>IMAGE_PARTITION_RESERVED_SIZE** being defined
+  will have a negative impact on the overall right-sizing of images
+  and thus free dynamic partition space.
 - Kernel must have CONFIG_OVERLAY_FS=y and will need to be patched
   with "*overlayfs: override_creds=off option bypass creator_cred*"
   if higher than 4.6.
 - *adb enable-verity* will free up overlayfs and as a bonus the
   device will be reverted pristine to before any content was updated.
   Update engine does not take advantage of this, will perform a full OTA.
-- Update engine will not run if *fs_mgr_overlayfs_is_setup*() reports
-  true as adb remount overrides are incompatable with an OTA for
-  multiple reasons.
-  NB: This is not a problem for fastbootd or recovery as overrides are
-  disabled for those special boot scenarios.
+- Update engine may not run if *fs_mgr_overlayfs_is_setup*() reports
+  true as adb remount overrides are incompatable with an OTA resources.
 - For implementation simplicity on retrofit dynamic partition devices,
   take the whole alternate super (eg: if "*a*" slot, then the whole of
   "*system_b*").
diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 60ce452..943fe10 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -91,6 +91,8 @@
 using android::fs_mgr::AvbHashtreeResult;
 using android::fs_mgr::AvbUniquePtr;
 
+using namespace std::literals;
+
 // record fs stat
 enum FsStatFlags {
     FS_STAT_IS_EXT4 = 0x0001,
@@ -131,10 +133,10 @@
     }
 }
 
-static void log_fs_stat(const char* blk_device, int fs_stat)
-{
+static void log_fs_stat(const std::string& blk_device, int fs_stat) {
     if ((fs_stat & FS_STAT_IS_EXT4) == 0) return; // only log ext4
-    std::string msg = android::base::StringPrintf("\nfs_stat,%s,0x%x\n", blk_device, fs_stat);
+    std::string msg =
+            android::base::StringPrintf("\nfs_stat,%s,0x%x\n", blk_device.c_str(), fs_stat);
     android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(FSCK_LOG_FILE, O_WRONLY | O_CLOEXEC |
                                                         O_APPEND | O_CREAT, 0664)));
     if (fd == -1 || !android::base::WriteStringToFd(msg, fd)) {
@@ -150,7 +152,7 @@
     return fs_type == "f2fs";
 }
 
-static std::string realpath(const char* blk_device) {
+static std::string realpath(const std::string& blk_device) {
     std::string real_path;
     if (!Realpath(blk_device, &real_path)) {
         real_path = blk_device;
@@ -166,14 +168,14 @@
             FS_STAT_SET_RESERVED_BLOCKS_FAILED | FS_STAT_ENABLE_ENCRYPTION_FAILED);
 }
 
-static void check_fs(const char *blk_device, char *fs_type, char *target, int *fs_stat)
-{
+static void check_fs(const std::string& blk_device, const std::string& fs_type,
+                     const std::string& target, int* fs_stat) {
     int status;
     int ret;
     long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
-    char tmpmnt_opts[64] = "errors=remount-ro";
-    const char* e2fsck_argv[] = {E2FSCK_BIN, "-y", blk_device};
-    const char* e2fsck_forced_argv[] = {E2FSCK_BIN, "-f", "-y", blk_device};
+    auto tmpmnt_opts = "errors=remount-ro"s;
+    const char* e2fsck_argv[] = {E2FSCK_BIN, "-y", blk_device.c_str()};
+    const char* e2fsck_forced_argv[] = {E2FSCK_BIN, "-f", "-y", blk_device.c_str()};
 
     if (*fs_stat & FS_STAT_INVALID_MAGIC) {  // will fail, so do not try
         return;
@@ -196,18 +198,19 @@
          */
         if (!(*fs_stat & FS_STAT_FULL_MOUNT_FAILED)) {  // already tried if full mount failed
             errno = 0;
-            if (!strcmp(fs_type, "ext4")) {
+            if (fs_type == "ext4") {
                 // This option is only valid with ext4
-                strlcat(tmpmnt_opts, ",nomblk_io_submit", sizeof(tmpmnt_opts));
+                tmpmnt_opts += ",nomblk_io_submit";
             }
-            ret = mount(blk_device, target, fs_type, tmpmnt_flags, tmpmnt_opts);
+            ret = mount(blk_device.c_str(), target.c_str(), fs_type.c_str(), tmpmnt_flags,
+                        tmpmnt_opts.c_str());
             PINFO << __FUNCTION__ << "(): mount(" << blk_device << "," << target << "," << fs_type
                   << ")=" << ret;
             if (!ret) {
                 bool umounted = false;
                 int retry_count = 5;
                 while (retry_count-- > 0) {
-                    umounted = umount(target) == 0;
+                    umounted = umount(target.c_str()) == 0;
                     if (umounted) {
                         LINFO << __FUNCTION__ << "(): unmount(" << target << ") succeeded";
                         break;
@@ -254,7 +257,7 @@
             }
         }
     } else if (is_f2fs(fs_type)) {
-        const char* f2fs_fsck_argv[] = {F2FS_FSCK_BIN, "-a", blk_device};
+        const char* f2fs_fsck_argv[] = {F2FS_FSCK_BIN, "-a", blk_device.c_str()};
         LINFO << "Running " << F2FS_FSCK_BIN << " -a " << realpath(blk_device);
 
         ret = android_fork_execvp_ext(ARRAY_SIZE(f2fs_fsck_argv),
@@ -290,8 +293,9 @@
 
 // Read the primary superblock from an ext4 filesystem.  On failure return
 // false.  If it's not an ext4 filesystem, also set FS_STAT_INVALID_MAGIC.
-static bool read_ext4_superblock(const char* blk_device, struct ext4_super_block* sb, int* fs_stat) {
-    android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device, O_RDONLY | O_CLOEXEC)));
+static bool read_ext4_superblock(const std::string& blk_device, struct ext4_super_block* sb,
+                                 int* fs_stat) {
+    android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
 
     if (fd < 0) {
         PERROR << "Failed to open '" << blk_device << "'";
@@ -332,10 +336,10 @@
 }
 
 // Enable/disable quota support on the filesystem if needed.
-static void tune_quota(const char* blk_device, const struct fstab_rec* rec,
+static void tune_quota(const std::string& blk_device, const FstabEntry& entry,
                        const struct ext4_super_block* sb, int* fs_stat) {
     bool has_quota = (sb->s_feature_ro_compat & cpu_to_le32(EXT4_FEATURE_RO_COMPAT_QUOTA)) != 0;
-    bool want_quota = fs_mgr_is_quota(rec) != 0;
+    bool want_quota = entry.fs_mgr_flags.quota;
 
     if (has_quota == want_quota) {
         return;
@@ -347,7 +351,7 @@
         return;
     }
 
-    const char* argv[] = {TUNE2FS_BIN, nullptr, nullptr, blk_device};
+    const char* argv[] = {TUNE2FS_BIN, nullptr, nullptr, blk_device.c_str()};
 
     if (want_quota) {
         LINFO << "Enabling quotas on " << blk_device;
@@ -368,16 +372,16 @@
 }
 
 // Set the number of reserved filesystem blocks if needed.
-static void tune_reserved_size(const char* blk_device, const struct fstab_rec* rec,
+static void tune_reserved_size(const std::string& blk_device, const FstabEntry& entry,
                                const struct ext4_super_block* sb, int* fs_stat) {
-    if (!(rec->fs_mgr_flags & MF_RESERVEDSIZE)) {
+    if (!entry.fs_mgr_flags.reserved_size) {
         return;
     }
 
     // The size to reserve is given in the fstab, but we won't reserve more
     // than 2% of the filesystem.
     const uint64_t max_reserved_blocks = ext4_blocks_count(sb) * 0.02;
-    uint64_t reserved_blocks = rec->reserved_size / EXT4_BLOCK_SIZE(sb);
+    uint64_t reserved_blocks = entry.reserved_size / EXT4_BLOCK_SIZE(sb);
 
     if (reserved_blocks > max_reserved_blocks) {
         LWARNING << "Reserved blocks " << reserved_blocks << " is too large; "
@@ -400,7 +404,8 @@
     auto reserved_blocks_str = std::to_string(reserved_blocks);
     auto reserved_gid_str = std::to_string(AID_RESERVED_DISK);
     const char* argv[] = {
-        TUNE2FS_BIN, "-r", reserved_blocks_str.c_str(), "-g", reserved_gid_str.c_str(), blk_device};
+            TUNE2FS_BIN,       "-r", reserved_blocks_str.c_str(), "-g", reserved_gid_str.c_str(),
+            blk_device.c_str()};
     if (!run_tune2fs(argv, ARRAY_SIZE(argv))) {
         LERROR << "Failed to run " TUNE2FS_BIN " to set the number of reserved blocks on "
                << blk_device;
@@ -409,10 +414,10 @@
 }
 
 // Enable file-based encryption if needed.
-static void tune_encrypt(const char* blk_device, const struct fstab_rec* rec,
+static void tune_encrypt(const std::string& blk_device, const FstabEntry& entry,
                          const struct ext4_super_block* sb, int* fs_stat) {
     bool has_encrypt = (sb->s_feature_incompat & cpu_to_le32(EXT4_FEATURE_INCOMPAT_ENCRYPT)) != 0;
-    bool want_encrypt = fs_mgr_is_file_encrypted(rec) != 0;
+    bool want_encrypt = entry.fs_mgr_flags.file_encryption;
 
     if (has_encrypt || !want_encrypt) {
         return;
@@ -424,7 +429,7 @@
         return;
     }
 
-    const char* argv[] = {TUNE2FS_BIN, "-Oencrypt", blk_device};
+    const char* argv[] = {TUNE2FS_BIN, "-Oencrypt", blk_device.c_str()};
 
     LINFO << "Enabling ext4 encryption on " << blk_device;
     if (!run_tune2fs(argv, ARRAY_SIZE(argv))) {
@@ -438,8 +443,8 @@
 // false.  If it's not an f2fs filesystem, also set FS_STAT_INVALID_MAGIC.
 #define F2FS_BLKSIZE 4096
 #define F2FS_SUPER_OFFSET 1024
-static bool read_f2fs_superblock(const char* blk_device, int* fs_stat) {
-    android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device, O_RDONLY | O_CLOEXEC)));
+static bool read_f2fs_superblock(const std::string& blk_device, int* fs_stat) {
+    android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
     __le32 sb1, sb2;
 
     if (fd < 0) {
@@ -473,10 +478,10 @@
 // If needed, we'll also enable (or disable) filesystem features as specified by
 // the fstab record.
 //
-static int prepare_fs_for_mount(const char* blk_device, const struct fstab_rec* rec) {
+static int prepare_fs_for_mount(const std::string& blk_device, const FstabEntry& entry) {
     int fs_stat = 0;
 
-    if (is_extfs(rec->fs_type)) {
+    if (is_extfs(entry.fs_type)) {
         struct ext4_super_block sb;
 
         if (read_ext4_superblock(blk_device, &sb, &fs_stat)) {
@@ -489,44 +494,34 @@
             }
 
             // Note: quotas should be enabled before running fsck.
-            tune_quota(blk_device, rec, &sb, &fs_stat);
+            tune_quota(blk_device, entry, &sb, &fs_stat);
         } else {
             return fs_stat;
         }
-    } else if (is_f2fs(rec->fs_type)) {
+    } else if (is_f2fs(entry.fs_type)) {
         if (!read_f2fs_superblock(blk_device, &fs_stat)) {
             return fs_stat;
         }
     }
 
-    if ((rec->fs_mgr_flags & MF_CHECK) ||
+    if (entry.fs_mgr_flags.check ||
         (fs_stat & (FS_STAT_UNCLEAN_SHUTDOWN | FS_STAT_QUOTA_ENABLED))) {
-        check_fs(blk_device, rec->fs_type, rec->mount_point, &fs_stat);
+        check_fs(blk_device, entry.fs_type, entry.mount_point, &fs_stat);
     }
 
-    if (is_extfs(rec->fs_type) && (rec->fs_mgr_flags & (MF_RESERVEDSIZE | MF_FILEENCRYPTION))) {
+    if (is_extfs(entry.fs_type) &&
+        (entry.fs_mgr_flags.reserved_size || entry.fs_mgr_flags.file_encryption)) {
         struct ext4_super_block sb;
 
         if (read_ext4_superblock(blk_device, &sb, &fs_stat)) {
-            tune_reserved_size(blk_device, rec, &sb, &fs_stat);
-            tune_encrypt(blk_device, rec, &sb, &fs_stat);
+            tune_reserved_size(blk_device, entry, &sb, &fs_stat);
+            tune_encrypt(blk_device, entry, &sb, &fs_stat);
         }
     }
 
     return fs_stat;
 }
 
-static void remove_trailing_slashes(char *n)
-{
-    int len;
-
-    len = strlen(n) - 1;
-    while ((*(n + len) == '/') && len) {
-      *(n + len) = '\0';
-      len--;
-    }
-}
-
 // Mark the given block device as read-only, using the BLKROSET ioctl.
 bool fs_mgr_set_blk_ro(const std::string& blockdev) {
     unique_fd fd(TEMP_FAILURE_RETRY(open(blockdev.c_str(), O_RDONLY | O_CLOEXEC)));
@@ -548,40 +543,34 @@
     return false;
 }
 
-/*
- * __mount(): wrapper around the mount() system call which also
- * sets the underlying block device to read-only if the mount is read-only.
- * See "man 2 mount" for return values.
- */
-static int __mount(const char *source, const char *target, const struct fstab_rec *rec)
-{
-    unsigned long mountflags = rec->flags;
-    int ret;
-    int save_errno;
-
-    /* We need this because sometimes we have legacy symlinks
-     * that are lingering around and need cleaning up.
-     */
+// __mount(): wrapper around the mount() system call which also
+// sets the underlying block device to read-only if the mount is read-only.
+// See "man 2 mount" for return values.
+static int __mount(const std::string& source, const std::string& target, const FstabEntry& entry) {
+    // We need this because sometimes we have legacy symlinks that are
+    // lingering around and need cleaning up.
     struct stat info;
-    if (!lstat(target, &info))
-        if ((info.st_mode & S_IFMT) == S_IFLNK)
-            unlink(target);
-    mkdir(target, 0755);
+    if (lstat(target.c_str(), &info) == 0 && (info.st_mode & S_IFMT) == S_IFLNK) {
+        unlink(target.c_str());
+    }
+    mkdir(target.c_str(), 0755);
     errno = 0;
-    ret = mount(source, target, rec->fs_type, mountflags, rec->fs_options);
-    save_errno = errno;
+    unsigned long mountflags = entry.flags;
+    int ret = mount(source.c_str(), target.c_str(), entry.fs_type.c_str(), mountflags,
+                    entry.fs_options.c_str());
+    int save_errno = errno;
     const char* target_missing = "";
     const char* source_missing = "";
     if (save_errno == ENOENT) {
-        if (access(target, F_OK)) {
+        if (access(target.c_str(), F_OK)) {
             target_missing = "(missing)";
-        } else if (access(source, F_OK)) {
+        } else if (access(source.c_str(), F_OK)) {
             source_missing = "(missing)";
         }
         errno = save_errno;
     }
     PINFO << __FUNCTION__ << "(source=" << source << source_missing << ",target=" << target
-          << target_missing << ",type=" << rec->fs_type << ")=" << ret;
+          << target_missing << ",type=" << entry.fs_type << ")=" << ret;
     if ((ret == 0) && (mountflags & MS_RDONLY) != 0) {
         fs_mgr_set_blk_ro(source);
     }
@@ -589,126 +578,116 @@
     return ret;
 }
 
-static int fs_match(const char *in1, const char *in2)
-{
-    char *n1;
-    char *n2;
-    int ret;
-
-    n1 = strdup(in1);
-    n2 = strdup(in2);
-
-    remove_trailing_slashes(n1);
-    remove_trailing_slashes(n2);
-
-    ret = !strcmp(n1, n2);
-
-    free(n1);
-    free(n2);
-
-    return ret;
-}
-
-/*
- * Tries to mount any of the consecutive fstab entries that match
- * the mountpoint of the one given by fstab->recs[start_idx].
- *
- * end_idx: On return, will be the last rec that was looked at.
- * attempted_idx: On return, will indicate which fstab rec
- *     succeeded. In case of failure, it will be the start_idx.
- * Returns
- *   -1 on failure with errno set to match the 1st mount failure.
- *   0 on success.
- */
-static int mount_with_alternatives(fstab* fstab, int start_idx, int* end_idx, int* attempted_idx) {
-    int i;
-    int mount_errno = 0;
-    int mounted = 0;
-
-    if (!end_idx || !attempted_idx || start_idx >= fstab->num_entries) {
-      errno = EINVAL;
-      if (end_idx) *end_idx = start_idx;
-      if (attempted_idx) *attempted_idx = start_idx;
-      return -1;
+static bool fs_match(const std::string& in1, const std::string& in2) {
+    if (in1.empty() || in2.empty()) {
+        return false;
     }
 
-    /* Hunt down an fstab entry for the same mount point that might succeed */
+    auto in1_end = in1.size() - 1;
+    while (in1_end > 0 && in1[in1_end] == '/') {
+        in1_end--;
+    }
+
+    auto in2_end = in2.size() - 1;
+    while (in2_end > 0 && in2[in2_end] == '/') {
+        in2_end--;
+    }
+
+    if (in1_end != in2_end) {
+        return false;
+    }
+
+    for (size_t i = 0; i <= in1_end; ++i) {
+        if (in1[i] != in2[i]) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+// Tries to mount any of the consecutive fstab entries that match
+// the mountpoint of the one given by fstab[start_idx].
+//
+// end_idx: On return, will be the last entry that was looked at.
+// attempted_idx: On return, will indicate which fstab entry
+//     succeeded. In case of failure, it will be the start_idx.
+// Sets errno to match the 1st mount failure on failure.
+static bool mount_with_alternatives(const Fstab& fstab, int start_idx, int* end_idx,
+                                    int* attempted_idx) {
+    unsigned long i;
+    int mount_errno = 0;
+    bool mounted = false;
+
+    // Hunt down an fstab entry for the same mount point that might succeed.
     for (i = start_idx;
-         /* We required that fstab entries for the same mountpoint be consecutive */
-         i < fstab->num_entries && !strcmp(fstab->recs[start_idx].mount_point, fstab->recs[i].mount_point);
-         i++) {
-            /*
-             * Don't try to mount/encrypt the same mount point again.
-             * Deal with alternate entries for the same point which are required to be all following
-             * each other.
-             */
-            if (mounted) {
-                LERROR << __FUNCTION__ << "(): skipping fstab dup mountpoint="
-                       << fstab->recs[i].mount_point << " rec[" << i
-                       << "].fs_type=" << fstab->recs[i].fs_type
-                       << " already mounted as "
-                       << fstab->recs[*attempted_idx].fs_type;
-                continue;
-            }
+         // We required that fstab entries for the same mountpoint be consecutive.
+         i < fstab.size() && fstab[start_idx].mount_point == fstab[i].mount_point; i++) {
+        // Don't try to mount/encrypt the same mount point again.
+        // Deal with alternate entries for the same point which are required to be all following
+        // each other.
+        if (mounted) {
+            LERROR << __FUNCTION__ << "(): skipping fstab dup mountpoint=" << fstab[i].mount_point
+                   << " rec[" << i << "].fs_type=" << fstab[i].fs_type << " already mounted as "
+                   << fstab[*attempted_idx].fs_type;
+            continue;
+        }
 
-            int fs_stat = prepare_fs_for_mount(fstab->recs[i].blk_device, &fstab->recs[i]);
-            if (fs_stat & FS_STAT_INVALID_MAGIC) {
-                LERROR << __FUNCTION__ << "(): skipping mount due to invalid magic, mountpoint="
-                       << fstab->recs[i].mount_point
-                       << " blk_dev=" << realpath(fstab->recs[i].blk_device) << " rec[" << i
-                       << "].fs_type=" << fstab->recs[i].fs_type;
-                mount_errno = EINVAL;  // continue bootup for FDE
-                continue;
-            }
+        int fs_stat = prepare_fs_for_mount(fstab[i].blk_device, fstab[i]);
+        if (fs_stat & FS_STAT_INVALID_MAGIC) {
+            LERROR << __FUNCTION__
+                   << "(): skipping mount due to invalid magic, mountpoint=" << fstab[i].mount_point
+                   << " blk_dev=" << realpath(fstab[i].blk_device) << " rec[" << i
+                   << "].fs_type=" << fstab[i].fs_type;
+            mount_errno = EINVAL;  // continue bootup for FDE
+            continue;
+        }
 
-            int retry_count = 2;
-            while (retry_count-- > 0) {
-                if (!__mount(fstab->recs[i].blk_device, fstab->recs[i].mount_point,
-                             &fstab->recs[i])) {
-                    *attempted_idx = i;
-                    mounted = 1;
-                    if (i != start_idx) {
-                        LERROR << __FUNCTION__ << "(): Mounted " << fstab->recs[i].blk_device
-                               << " on " << fstab->recs[i].mount_point
-                               << " with fs_type=" << fstab->recs[i].fs_type << " instead of "
-                               << fstab->recs[start_idx].fs_type;
-                    }
-                    fs_stat &= ~FS_STAT_FULL_MOUNT_FAILED;
-                    mount_errno = 0;
-                    break;
-                } else {
-                    if (retry_count <= 0) break;  // run check_fs only once
-                    fs_stat |= FS_STAT_FULL_MOUNT_FAILED;
-                    /* back up the first errno for crypto decisions */
-                    if (mount_errno == 0) {
-                        mount_errno = errno;
-                    }
-                    // retry after fsck
-                    check_fs(fstab->recs[i].blk_device, fstab->recs[i].fs_type,
-                             fstab->recs[i].mount_point, &fs_stat);
+        int retry_count = 2;
+        while (retry_count-- > 0) {
+            if (!__mount(fstab[i].blk_device, fstab[i].mount_point, fstab[i])) {
+                *attempted_idx = i;
+                mounted = true;
+                if (i != start_idx) {
+                    LERROR << __FUNCTION__ << "(): Mounted " << fstab[i].blk_device << " on "
+                           << fstab[i].mount_point << " with fs_type=" << fstab[i].fs_type
+                           << " instead of " << fstab[start_idx].fs_type;
                 }
+                fs_stat &= ~FS_STAT_FULL_MOUNT_FAILED;
+                mount_errno = 0;
+                break;
+            } else {
+                if (retry_count <= 0) break;  // run check_fs only once
+                fs_stat |= FS_STAT_FULL_MOUNT_FAILED;
+                // back up the first errno for crypto decisions.
+                if (mount_errno == 0) {
+                    mount_errno = errno;
+                }
+                // retry after fsck
+                check_fs(fstab[i].blk_device, fstab[i].fs_type, fstab[i].mount_point, &fs_stat);
             }
-            log_fs_stat(fstab->recs[i].blk_device, fs_stat);
+        }
+        log_fs_stat(fstab[i].blk_device, fs_stat);
     }
 
     /* Adjust i for the case where it was still withing the recs[] */
-    if (i < fstab->num_entries) --i;
+    if (i < fstab.size()) --i;
 
     *end_idx = i;
     if (!mounted) {
         *attempted_idx = start_idx;
         errno = mount_errno;
-        return -1;
+        return false;
     }
-    return 0;
+    return true;
 }
 
-static bool TranslateExtLabels(fstab_rec* rec) {
-    if (!StartsWith(rec->blk_device, "LABEL=")) {
+static bool TranslateExtLabels(FstabEntry* entry) {
+    if (!StartsWith(entry->blk_device, "LABEL=")) {
         return true;
     }
 
-    std::string label = rec->blk_device + 6;
+    std::string label = entry->blk_device.substr(6);
     if (label.size() > 16) {
         LERROR << "FS label is longer than allowed by filesystem";
         return false;
@@ -746,17 +725,11 @@
         }
 
         if (label == super_block.s_volume_name) {
-            char* new_blk_device;
+            std::string new_blk_device = "/dev/block/"s + ent->d_name;
 
-            if (asprintf(&new_blk_device, "/dev/block/%s", ent->d_name) < 0) {
-                LERROR << "Could not allocate block device string";
-                return false;
-            }
+            LINFO << "resolved label " << entry->blk_device << " to " << new_blk_device;
 
-            LINFO << "resolved label " << rec->blk_device << " to " << new_blk_device;
-
-            free(rec->blk_device);
-            rec->blk_device = new_blk_device;
+            entry->blk_device = new_blk_device;
             return true;
         }
     }
@@ -764,58 +737,49 @@
     return false;
 }
 
-static bool needs_block_encryption(const struct fstab_rec* rec)
-{
-    if (android::base::GetBoolProperty("ro.vold.forceencryption", false) &&
-        fs_mgr_is_encryptable(rec))
+static bool needs_block_encryption(const FstabEntry& entry) {
+    if (android::base::GetBoolProperty("ro.vold.forceencryption", false) && entry.is_encryptable())
         return true;
-    if (rec->fs_mgr_flags & MF_FORCECRYPT) return true;
-    if (rec->fs_mgr_flags & MF_CRYPT) {
-        /* Check for existence of convert_fde breadcrumb file */
-        char convert_fde_name[PATH_MAX];
-        snprintf(convert_fde_name, sizeof(convert_fde_name),
-                 "%s/misc/vold/convert_fde", rec->mount_point);
-        if (access(convert_fde_name, F_OK) == 0) return true;
+    if (entry.fs_mgr_flags.force_crypt) return true;
+    if (entry.fs_mgr_flags.crypt) {
+        // Check for existence of convert_fde breadcrumb file.
+        auto convert_fde_name = entry.mount_point + "/misc/vold/convert_fde";
+        if (access(convert_fde_name.c_str(), F_OK) == 0) return true;
     }
-    if (rec->fs_mgr_flags & MF_FORCEFDEORFBE) {
-        /* Check for absence of convert_fbe breadcrumb file */
-        char convert_fbe_name[PATH_MAX];
-        snprintf(convert_fbe_name, sizeof(convert_fbe_name),
-                 "%s/convert_fbe", rec->mount_point);
-        if (access(convert_fbe_name, F_OK) != 0) return true;
+    if (entry.fs_mgr_flags.force_fde_or_fbe) {
+        // Check for absence of convert_fbe breadcrumb file.
+        auto convert_fbe_name = entry.mount_point + "/convert_fbe";
+        if (access(convert_fbe_name.c_str(), F_OK) != 0) return true;
     }
     return false;
 }
 
-static bool should_use_metadata_encryption(const struct fstab_rec* rec) {
-    if (!(rec->fs_mgr_flags & (MF_FILEENCRYPTION | MF_FORCEFDEORFBE))) return false;
-    if (!(rec->fs_mgr_flags & MF_KEYDIRECTORY)) return false;
-    return true;
+static bool should_use_metadata_encryption(const FstabEntry& entry) {
+    return entry.fs_mgr_flags.key_directory &&
+           (entry.fs_mgr_flags.file_encryption || entry.fs_mgr_flags.force_fde_or_fbe);
 }
 
 // Check to see if a mountable volume has encryption requirements
-static int handle_encryptable(const struct fstab_rec* rec)
-{
-    /* If this is block encryptable, need to trigger encryption */
-    if (needs_block_encryption(rec)) {
-        if (umount(rec->mount_point) == 0) {
+static int handle_encryptable(const FstabEntry& entry) {
+    // If this is block encryptable, need to trigger encryption.
+    if (needs_block_encryption(entry)) {
+        if (umount(entry.mount_point.c_str()) == 0) {
             return FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION;
         } else {
-            PWARNING << "Could not umount " << rec->mount_point
-                     << " - allow continue unencrypted";
+            PWARNING << "Could not umount " << entry.mount_point << " - allow continue unencrypted";
             return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
         }
-    } else if (should_use_metadata_encryption(rec)) {
-        if (umount(rec->mount_point) == 0) {
+    } else if (should_use_metadata_encryption(entry)) {
+        if (umount(entry.mount_point.c_str()) == 0) {
             return FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION;
         } else {
-            PERROR << "Could not umount " << rec->mount_point << " - fail since can't encrypt";
+            PERROR << "Could not umount " << entry.mount_point << " - fail since can't encrypt";
             return FS_MGR_MNTALL_FAIL;
         }
-    } else if (rec->fs_mgr_flags & (MF_FILEENCRYPTION | MF_FORCEFDEORFBE)) {
-        LINFO << rec->mount_point << " is file encrypted";
+    } else if (entry.fs_mgr_flags.file_encryption || entry.fs_mgr_flags.force_fde_or_fbe) {
+        LINFO << entry.mount_point << " is file encrypted";
         return FS_MGR_MNTALL_DEV_FILE_ENCRYPTED;
-    } else if (fs_mgr_is_encryptable(rec)) {
+    } else if (entry.is_encryptable()) {
         return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
     } else {
         return FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE;
@@ -856,21 +820,34 @@
     return true;
 }
 
-bool fs_mgr_update_logical_partition(struct fstab_rec* rec) {
+bool fs_mgr_update_logical_partition(FstabEntry* entry) {
     // Logical partitions are specified with a named partition rather than a
     // block device, so if the block device is a path, then it has already
     // been updated.
-    if (rec->blk_device[0] == '/') {
+    if (entry->blk_device[0] == '/') {
         return true;
     }
 
     DeviceMapper& dm = DeviceMapper::Instance();
     std::string device_name;
-    if (!dm.GetDmDevicePathByName(rec->blk_device, &device_name)) {
+    if (!dm.GetDmDevicePathByName(entry->blk_device, &device_name)) {
         return false;
     }
+
+    entry->blk_device = device_name;
+    return true;
+}
+
+bool fs_mgr_update_logical_partition(struct fstab_rec* rec) {
+    auto entry = FstabRecToFstabEntry(rec);
+
+    if (!fs_mgr_update_logical_partition(&entry)) {
+        return false;
+    }
+
     free(rec->blk_device);
-    rec->blk_device = strdup(device_name.c_str());
+    rec->blk_device = strdup(entry.blk_device.c_str());
+
     return true;
 }
 
@@ -878,13 +855,13 @@
   public:
     CheckpointManager(int needs_checkpoint = -1) : needs_checkpoint_(needs_checkpoint) {}
 
-    bool Update(struct fstab_rec* rec) {
-        if (!fs_mgr_is_checkpoint(rec)) {
+    bool Update(FstabEntry* entry) {
+        if (!entry->fs_mgr_flags.checkpoint_blk && !entry->fs_mgr_flags.checkpoint_fs) {
             return true;
         }
 
-        if (fs_mgr_is_checkpoint_blk(rec)) {
-            call_vdc({"checkpoint", "restoreCheckpoint", rec->blk_device});
+        if (entry->fs_mgr_flags.checkpoint_blk) {
+            call_vdc({"checkpoint", "restoreCheckpoint", entry->blk_device});
         }
 
         if (needs_checkpoint_ == UNKNOWN &&
@@ -897,7 +874,7 @@
             return true;
         }
 
-        if (!UpdateCheckpointPartition(rec)) {
+        if (!UpdateCheckpointPartition(entry)) {
             LERROR << "Could not set up checkpoint partition, skipping!";
             return false;
         }
@@ -905,18 +882,17 @@
         return true;
     }
 
-    bool Revert(struct fstab_rec* rec) {
-        if (!fs_mgr_is_checkpoint(rec)) {
+    bool Revert(FstabEntry* entry) {
+        if (!entry->fs_mgr_flags.checkpoint_blk && !entry->fs_mgr_flags.checkpoint_fs) {
             return true;
         }
 
-        if (device_map_.find(rec->blk_device) == device_map_.end()) {
+        if (device_map_.find(entry->blk_device) == device_map_.end()) {
             return true;
         }
 
-        std::string bow_device = rec->blk_device;
-        free(rec->blk_device);
-        rec->blk_device = strdup(device_map_[bow_device].c_str());
+        std::string bow_device = entry->blk_device;
+        entry->blk_device = device_map_[bow_device];
         device_map_.erase(bow_device);
 
         DeviceMapper& dm = DeviceMapper::Instance();
@@ -928,21 +904,17 @@
     }
 
   private:
-    bool UpdateCheckpointPartition(struct fstab_rec* rec) {
-        if (fs_mgr_is_checkpoint_fs(rec)) {
-            if (is_f2fs(rec->fs_type)) {
-                std::string opts(rec->fs_options);
-
-                opts += ",checkpoint=disable";
-                free(rec->fs_options);
-                rec->fs_options = strdup(opts.c_str());
+    bool UpdateCheckpointPartition(FstabEntry* entry) {
+        if (entry->fs_mgr_flags.checkpoint_fs) {
+            if (is_f2fs(entry->fs_type)) {
+                entry->fs_options += ",checkpoint=disable";
             } else {
-                LERROR << rec->fs_type << " does not implement checkpoints.";
+                LERROR << entry->fs_type << " does not implement checkpoints.";
             }
-        } else if (fs_mgr_is_checkpoint_blk(rec)) {
-            unique_fd fd(TEMP_FAILURE_RETRY(open(rec->blk_device, O_RDONLY | O_CLOEXEC)));
+        } else if (entry->fs_mgr_flags.checkpoint_blk) {
+            unique_fd fd(TEMP_FAILURE_RETRY(open(entry->blk_device.c_str(), O_RDONLY | O_CLOEXEC)));
             if (fd < 0) {
-                PERROR << "Cannot open device " << rec->blk_device;
+                PERROR << "Cannot open device " << entry->blk_device;
                 return false;
             }
 
@@ -954,7 +926,7 @@
 
             android::dm::DmTable table;
             if (!table.AddTarget(
-                        std::make_unique<android::dm::DmTargetBow>(0, size, rec->blk_device))) {
+                        std::make_unique<android::dm::DmTargetBow>(0, size, entry->blk_device))) {
                 LERROR << "Failed to add bow target";
                 return false;
             }
@@ -971,9 +943,8 @@
                 return false;
             }
 
-            device_map_[name] = rec->blk_device;
-            free(rec->blk_device);
-            rec->blk_device = strdup(name.c_str());
+            device_map_[name] = entry->blk_device;
+            entry->blk_device = name;
         }
         return true;
     }
@@ -983,76 +954,70 @@
     std::map<std::string, std::string> device_map_;
 };
 
-/* When multiple fstab records share the same mount_point, it will
- * try to mount each one in turn, and ignore any duplicates after a
- * first successful mount.
- * Returns -1 on error, and  FS_MGR_MNTALL_* otherwise.
- */
-int fs_mgr_mount_all(fstab* fstab, int mount_mode) {
-    int i = 0;
+// When multiple fstab records share the same mount_point, it will try to mount each
+// one in turn, and ignore any duplicates after a first successful mount.
+// Returns -1 on error, and  FS_MGR_MNTALL_* otherwise.
+int fs_mgr_mount_all(Fstab* fstab, int mount_mode) {
     int encryptable = FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE;
     int error_count = 0;
-    int mret = -1;
-    int mount_errno = 0;
-    int attempted_idx = -1;
     CheckpointManager checkpoint_manager;
     AvbUniquePtr avb_handle(nullptr);
 
-    if (!fstab) {
+    if (fstab->empty()) {
         return FS_MGR_MNTALL_FAIL;
     }
 
-    for (i = 0; i < fstab->num_entries; i++) {
-        /* Don't mount entries that are managed by vold or not for the mount mode*/
-        if ((fstab->recs[i].fs_mgr_flags & (MF_VOLDMANAGED | MF_RECOVERYONLY)) ||
-            ((mount_mode == MOUNT_MODE_LATE) && !fs_mgr_is_latemount(&fstab->recs[i])) ||
-            ((mount_mode == MOUNT_MODE_EARLY) && fs_mgr_is_latemount(&fstab->recs[i])) ||
-            fs_mgr_is_first_stage_mount(&fstab->recs[i])) {
+    for (size_t i = 0; i < fstab->size(); i++) {
+        auto& current_entry = (*fstab)[i];
+
+        // Don't mount entries that are managed by vold or not for the mount mode.
+        if (current_entry.fs_mgr_flags.vold_managed || current_entry.fs_mgr_flags.recovery_only ||
+            current_entry.fs_mgr_flags.first_stage_mount ||
+            ((mount_mode == MOUNT_MODE_LATE) && !current_entry.fs_mgr_flags.late_mount) ||
+            ((mount_mode == MOUNT_MODE_EARLY) && current_entry.fs_mgr_flags.late_mount)) {
             continue;
         }
 
-        /* Skip swap and raw partition entries such as boot, recovery, etc */
-        if (!strcmp(fstab->recs[i].fs_type, "swap") ||
-            !strcmp(fstab->recs[i].fs_type, "emmc") ||
-            !strcmp(fstab->recs[i].fs_type, "mtd")) {
+        // Skip swap and raw partition entries such as boot, recovery, etc.
+        if (current_entry.fs_type == "swap" || current_entry.fs_type == "emmc" ||
+            current_entry.fs_type == "mtd") {
             continue;
         }
 
-        /* Skip mounting the root partition, as it will already have been mounted */
-        if (!strcmp(fstab->recs[i].mount_point, "/") ||
-            !strcmp(fstab->recs[i].mount_point, "/system")) {
-            if ((fstab->recs[i].flags & MS_RDONLY) != 0) {
-                fs_mgr_set_blk_ro(fstab->recs[i].blk_device);
+        // Skip mounting the root partition, as it will already have been mounted.
+        if (current_entry.mount_point == "/" || current_entry.mount_point == "/system") {
+            if ((current_entry.flags & MS_RDONLY) != 0) {
+                fs_mgr_set_blk_ro(current_entry.blk_device);
             }
             continue;
         }
 
-        /* Translate LABEL= file system labels into block devices */
-        if (is_extfs(fstab->recs[i].fs_type)) {
-            if (!TranslateExtLabels(&fstab->recs[i])) {
+        // Translate LABEL= file system labels into block devices.
+        if (is_extfs(current_entry.fs_type)) {
+            if (!TranslateExtLabels(&current_entry)) {
                 LERROR << "Could not translate label to block device";
                 continue;
             }
         }
 
-        if ((fstab->recs[i].fs_mgr_flags & MF_LOGICAL)) {
-            if (!fs_mgr_update_logical_partition(&fstab->recs[i])) {
+        if (current_entry.fs_mgr_flags.logical) {
+            if (!fs_mgr_update_logical_partition(&current_entry)) {
                 LERROR << "Could not set up logical partition, skipping!";
                 continue;
             }
         }
 
-        if (!checkpoint_manager.Update(&fstab->recs[i])) {
+        if (!checkpoint_manager.Update(&current_entry)) {
             continue;
         }
 
-        if (fstab->recs[i].fs_mgr_flags & MF_WAIT &&
-            !fs_mgr_wait_for_file(fstab->recs[i].blk_device, 20s)) {
-            LERROR << "Skipping '" << fstab->recs[i].blk_device << "' during mount_all";
+        if (current_entry.fs_mgr_flags.wait &&
+            !fs_mgr_wait_for_file(current_entry.blk_device, 20s)) {
+            LERROR << "Skipping '" << current_entry.blk_device << "' during mount_all";
             continue;
         }
 
-        if (fstab->recs[i].fs_mgr_flags & MF_AVB) {
+        if (current_entry.fs_mgr_flags.avb) {
             if (!avb_handle) {
                 avb_handle = AvbHandle::Open();
                 if (!avb_handle) {
@@ -1060,15 +1025,15 @@
                     return FS_MGR_MNTALL_FAIL;
                 }
             }
-            if (avb_handle->SetUpAvbHashtree(&fstab->recs[i], true /* wait_for_verity_dev */) ==
+            if (avb_handle->SetUpAvbHashtree(&current_entry, true /* wait_for_verity_dev */) ==
                 AvbHashtreeResult::kFail) {
-                LERROR << "Failed to set up AVB on partition: "
-                       << fstab->recs[i].mount_point << ", skipping!";
-                /* Skips mounting the device. */
+                LERROR << "Failed to set up AVB on partition: " << current_entry.mount_point
+                       << ", skipping!";
+                // Skips mounting the device.
                 continue;
             }
-        } else if ((fstab->recs[i].fs_mgr_flags & MF_VERIFY)) {
-            int rc = fs_mgr_setup_verity(&fstab->recs[i], true);
+        } else if ((current_entry.fs_mgr_flags.verify)) {
+            int rc = fs_mgr_setup_verity(&current_entry, true);
             if (__android_log_is_debuggable() &&
                     (rc == FS_MGR_SETUP_VERITY_DISABLED ||
                      rc == FS_MGR_SETUP_VERITY_SKIPPED)) {
@@ -1081,17 +1046,19 @@
 
         int last_idx_inspected;
         int top_idx = i;
+        int attempted_idx = -1;
 
-        mret = mount_with_alternatives(fstab, i, &last_idx_inspected, &attempted_idx);
+        bool mret = mount_with_alternatives(*fstab, i, &last_idx_inspected, &attempted_idx);
+        auto& attempted_entry = (*fstab)[attempted_idx];
         i = last_idx_inspected;
-        mount_errno = errno;
+        int mount_errno = errno;
 
-        /* Deal with encryptability. */
-        if (!mret) {
-            int status = handle_encryptable(&fstab->recs[attempted_idx]);
+        // Handle success and deal with encryptability.
+        if (mret) {
+            int status = handle_encryptable(attempted_entry);
 
             if (status == FS_MGR_MNTALL_FAIL) {
-                /* Fatal error - no point continuing */
+                // Fatal error - no point continuing.
                 return status;
             }
 
@@ -1102,50 +1069,45 @@
                 }
                 encryptable = status;
                 if (status == FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION) {
-                    if (!call_vdc(
-                            {"cryptfs", "encryptFstab", fstab->recs[attempted_idx].mount_point})) {
+                    if (!call_vdc({"cryptfs", "encryptFstab", attempted_entry.mount_point})) {
                         LERROR << "Encryption failed";
                         return FS_MGR_MNTALL_FAIL;
                     }
                 }
             }
 
-            /* Success!  Go get the next one */
+            // Success!  Go get the next one.
             continue;
         }
 
-        bool wiped = partition_wiped(fstab->recs[top_idx].blk_device);
+        // Mounting failed, understand why and retry.
+        bool wiped = partition_wiped(current_entry.blk_device.c_str());
         bool crypt_footer = false;
-        if (mret && mount_errno != EBUSY && mount_errno != EACCES &&
-            fs_mgr_is_formattable(&fstab->recs[top_idx]) && wiped) {
-            /* top_idx and attempted_idx point at the same partition, but sometimes
-             * at two different lines in the fstab.  Use the top one for formatting
-             * as that is the preferred one.
-             */
-            LERROR << __FUNCTION__ << "(): " << realpath(fstab->recs[top_idx].blk_device)
-                   << " is wiped and " << fstab->recs[top_idx].mount_point << " "
-                   << fstab->recs[top_idx].fs_type << " is formattable. Format it.";
+        if (mount_errno != EBUSY && mount_errno != EACCES &&
+            current_entry.fs_mgr_flags.formattable && wiped) {
+            // current_entry and attempted_entry point at the same partition, but sometimes
+            // at two different lines in the fstab.  Use current_entry for formatting
+            // as that is the preferred one.
+            LERROR << __FUNCTION__ << "(): " << realpath(current_entry.blk_device)
+                   << " is wiped and " << current_entry.mount_point << " " << current_entry.fs_type
+                   << " is formattable. Format it.";
 
-            checkpoint_manager.Revert(&fstab->recs[top_idx]);
+            checkpoint_manager.Revert(&current_entry);
 
-            if (fs_mgr_is_encryptable(&fstab->recs[top_idx]) &&
-                strcmp(fstab->recs[top_idx].key_loc, KEY_IN_FOOTER)) {
+            if (current_entry.is_encryptable() && current_entry.key_loc != KEY_IN_FOOTER) {
                 unique_fd fd(TEMP_FAILURE_RETRY(
-                        open(fstab->recs[top_idx].key_loc, O_WRONLY | O_CLOEXEC)));
+                        open(current_entry.key_loc.c_str(), O_WRONLY | O_CLOEXEC)));
                 if (fd >= 0) {
-                    LINFO << __FUNCTION__ << "(): also wipe "
-                          << fstab->recs[top_idx].key_loc;
+                    LINFO << __FUNCTION__ << "(): also wipe " << current_entry.key_loc;
                     wipe_block_device(fd, get_file_size(fd));
                 } else {
-                    PERROR << __FUNCTION__ << "(): "
-                           << fstab->recs[top_idx].key_loc << " wouldn't open";
+                    PERROR << __FUNCTION__ << "(): " << current_entry.key_loc << " wouldn't open";
                 }
-            } else if (fs_mgr_is_encryptable(&fstab->recs[top_idx]) &&
-                !strcmp(fstab->recs[top_idx].key_loc, KEY_IN_FOOTER)) {
+            } else if (current_entry.is_encryptable() && current_entry.key_loc == KEY_IN_FOOTER) {
                 crypt_footer = true;
             }
-            if (fs_mgr_do_format(&fstab->recs[top_idx], crypt_footer) == 0) {
-                /* Let's replay the mount actions. */
+            if (fs_mgr_do_format(current_entry, crypt_footer) == 0) {
+                // Let's replay the mount actions.
                 i = top_idx - 1;
                 continue;
             } else {
@@ -1156,35 +1118,29 @@
             }
         }
 
-        /* mount(2) returned an error, handle the encryptable/formattable case */
-        if (mret && mount_errno != EBUSY && mount_errno != EACCES &&
-            fs_mgr_is_encryptable(&fstab->recs[attempted_idx])) {
+        // mount(2) returned an error, handle the encryptable/formattable case.
+        if (mount_errno != EBUSY && mount_errno != EACCES && attempted_entry.is_encryptable()) {
             if (wiped) {
-                LERROR << __FUNCTION__ << "(): "
-                       << fstab->recs[attempted_idx].blk_device
-                       << " is wiped and "
-                       << fstab->recs[attempted_idx].mount_point << " "
-                       << fstab->recs[attempted_idx].fs_type
+                LERROR << __FUNCTION__ << "(): " << attempted_entry.blk_device << " is wiped and "
+                       << attempted_entry.mount_point << " " << attempted_entry.fs_type
                        << " is encryptable. Suggest recovery...";
                 encryptable = FS_MGR_MNTALL_DEV_NEEDS_RECOVERY;
                 continue;
             } else {
-                /* Need to mount a tmpfs at this mountpoint for now, and set
-                 * properties that vold will query later for decrypting
-                 */
+                // Need to mount a tmpfs at this mountpoint for now, and set
+                // properties that vold will query later for decrypting
                 LERROR << __FUNCTION__ << "(): possibly an encryptable blkdev "
-                       << fstab->recs[attempted_idx].blk_device
-                       << " for mount " << fstab->recs[attempted_idx].mount_point
-                       << " type " << fstab->recs[attempted_idx].fs_type;
-                if (fs_mgr_do_tmpfs_mount(fstab->recs[attempted_idx].mount_point) < 0) {
+                       << attempted_entry.blk_device << " for mount " << attempted_entry.mount_point
+                       << " type " << attempted_entry.fs_type;
+                if (fs_mgr_do_tmpfs_mount(attempted_entry.mount_point.c_str()) < 0) {
                     ++error_count;
                     continue;
                 }
             }
             encryptable = FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED;
-        } else if (mret && mount_errno != EBUSY && mount_errno != EACCES &&
-                   should_use_metadata_encryption(&fstab->recs[attempted_idx])) {
-            if (!call_vdc({"cryptfs", "mountFstab", fstab->recs[attempted_idx].mount_point})) {
+        } else if (mount_errno != EBUSY && mount_errno != EACCES &&
+                   should_use_metadata_encryption(attempted_entry)) {
+            if (!call_vdc({"cryptfs", "mountFstab", attempted_entry.mount_point})) {
                 ++error_count;
             }
             encryptable = FS_MGR_MNTALL_DEV_IS_METADATA_ENCRYPTED;
@@ -1192,18 +1148,18 @@
         } else {
             // fs_options might be null so we cannot use PERROR << directly.
             // Use StringPrintf to output "(null)" instead.
-            if (fs_mgr_is_nofail(&fstab->recs[attempted_idx])) {
+            if (attempted_entry.fs_mgr_flags.no_fail) {
                 PERROR << android::base::StringPrintf(
-                    "Ignoring failure to mount an un-encryptable or wiped "
-                    "partition on %s at %s options: %s",
-                    fstab->recs[attempted_idx].blk_device, fstab->recs[attempted_idx].mount_point,
-                    fstab->recs[attempted_idx].fs_options);
+                        "Ignoring failure to mount an un-encryptable or wiped "
+                        "partition on %s at %s options: %s",
+                        attempted_entry.blk_device.c_str(), attempted_entry.mount_point.c_str(),
+                        attempted_entry.fs_options.c_str());
             } else {
                 PERROR << android::base::StringPrintf(
-                    "Failed to mount an un-encryptable or wiped partition "
-                    "on %s at %s options: %s",
-                    fstab->recs[attempted_idx].blk_device, fstab->recs[attempted_idx].mount_point,
-                    fstab->recs[attempted_idx].fs_options);
+                        "Failed to mount an un-encryptable or wiped partition "
+                        "on %s at %s options: %s",
+                        attempted_entry.blk_device.c_str(), attempted_entry.mount_point.c_str(),
+                        attempted_entry.fs_options.c_str());
                 ++error_count;
             }
             continue;
@@ -1221,20 +1177,14 @@
     }
 }
 
-/* wrapper to __mount() and expects a fully prepared fstab_rec,
- * unlike fs_mgr_do_mount which does more things with avb / verity
- * etc.
- */
-int fs_mgr_do_mount_one(struct fstab_rec *rec)
-{
-    if (!rec) {
-        return FS_MGR_DOMNT_FAILED;
-    }
-
+// wrapper to __mount() and expects a fully prepared fstab_rec,
+// unlike fs_mgr_do_mount which does more things with avb / verity etc.
+int fs_mgr_do_mount_one(const FstabEntry& entry, const std::string& mount_point) {
     // Run fsck if needed
-    prepare_fs_for_mount(rec->blk_device, rec);
+    prepare_fs_for_mount(entry.blk_device, entry);
 
-    int ret = __mount(rec->blk_device, rec->mount_point, rec);
+    int ret =
+            __mount(entry.blk_device, mount_point.empty() ? entry.mount_point : mount_point, entry);
     if (ret) {
       ret = (errno == EBUSY) ? FS_MGR_DOMNT_BUSY : FS_MGR_DOMNT_FAILED;
     }
@@ -1242,17 +1192,26 @@
     return ret;
 }
 
-/* If tmp_mount_point is non-null, mount the filesystem there.  This is for the
- * tmp mount we do to check the user password
- * If multiple fstab entries are to be mounted on "n_name", it will try to mount each one
- * in turn, and stop on 1st success, or no more match.
- */
-static int fs_mgr_do_mount_helper(fstab* fstab, const char* n_name, char* n_blk_device,
-                                  char* tmp_mount_point, int needs_checkpoint) {
-    int i = 0;
+int fs_mgr_do_mount_one(struct fstab_rec* rec) {
+    if (!rec) {
+        return FS_MGR_DOMNT_FAILED;
+    }
+
+    auto entry = FstabRecToFstabEntry(rec);
+
+    return fs_mgr_do_mount_one(entry);
+}
+
+// If tmp_mount_point is non-null, mount the filesystem there.  This is for the
+// tmp mount we do to check the user password
+// If multiple fstab entries are to be mounted on "n_name", it will try to mount each one
+// in turn, and stop on 1st success, or no more match.
+static int fs_mgr_do_mount_helper(Fstab* fstab, const std::string& n_name,
+                                  const std::string& n_blk_device, const char* tmp_mount_point,
+                                  int needs_checkpoint) {
     int mount_errors = 0;
     int first_mount_errno = 0;
-    char* mount_point;
+    std::string mount_point;
     CheckpointManager checkpoint_manager(needs_checkpoint);
     AvbUniquePtr avb_handle(nullptr);
 
@@ -1260,42 +1219,41 @@
         return FS_MGR_DOMNT_FAILED;
     }
 
-    for (i = 0; i < fstab->num_entries; i++) {
-        if (!fs_match(fstab->recs[i].mount_point, n_name)) {
+    for (auto& fstab_entry : *fstab) {
+        if (!fs_match(fstab_entry.mount_point, n_name)) {
             continue;
         }
 
-        /* We found our match */
-        /* If this swap or a raw partition, report an error */
-        if (!strcmp(fstab->recs[i].fs_type, "swap") ||
-            !strcmp(fstab->recs[i].fs_type, "emmc") ||
-            !strcmp(fstab->recs[i].fs_type, "mtd")) {
-            LERROR << "Cannot mount filesystem of type "
-                   << fstab->recs[i].fs_type << " on " << n_blk_device;
+        // We found our match.
+        // If this swap or a raw partition, report an error.
+        if (fstab_entry.fs_type == "swap" || fstab_entry.fs_type == "emmc" ||
+            fstab_entry.fs_type == "mtd") {
+            LERROR << "Cannot mount filesystem of type " << fstab_entry.fs_type << " on "
+                   << n_blk_device;
             return FS_MGR_DOMNT_FAILED;
         }
 
-        if ((fstab->recs[i].fs_mgr_flags & MF_LOGICAL)) {
-            if (!fs_mgr_update_logical_partition(&fstab->recs[i])) {
+        if (fstab_entry.fs_mgr_flags.logical) {
+            if (!fs_mgr_update_logical_partition(&fstab_entry)) {
                 LERROR << "Could not set up logical partition, skipping!";
                 continue;
             }
         }
 
-        if (!checkpoint_manager.Update(&fstab->recs[i])) {
+        if (!checkpoint_manager.Update(&fstab_entry)) {
             LERROR << "Could not set up checkpoint partition, skipping!";
             continue;
         }
 
-        /* First check the filesystem if requested */
-        if (fstab->recs[i].fs_mgr_flags & MF_WAIT && !fs_mgr_wait_for_file(n_blk_device, 20s)) {
+        // First check the filesystem if requested.
+        if (fstab_entry.fs_mgr_flags.wait && !fs_mgr_wait_for_file(n_blk_device, 20s)) {
             LERROR << "Skipping mounting '" << n_blk_device << "'";
             continue;
         }
 
-        int fs_stat = prepare_fs_for_mount(n_blk_device, &fstab->recs[i]);
+        int fs_stat = prepare_fs_for_mount(n_blk_device, fstab_entry);
 
-        if (fstab->recs[i].fs_mgr_flags & MF_AVB) {
+        if (fstab_entry.fs_mgr_flags.avb) {
             if (!avb_handle) {
                 avb_handle = AvbHandle::Open();
                 if (!avb_handle) {
@@ -1303,15 +1261,15 @@
                     return FS_MGR_DOMNT_FAILED;
                 }
             }
-            if (avb_handle->SetUpAvbHashtree(&fstab->recs[i], true /* wait_for_verity_dev */) ==
+            if (avb_handle->SetUpAvbHashtree(&fstab_entry, true /* wait_for_verity_dev */) ==
                 AvbHashtreeResult::kFail) {
-                LERROR << "Failed to set up AVB on partition: "
-                       << fstab->recs[i].mount_point << ", skipping!";
-                /* Skips mounting the device. */
+                LERROR << "Failed to set up AVB on partition: " << fstab_entry.mount_point
+                       << ", skipping!";
+                // Skips mounting the device.
                 continue;
             }
-        } else if ((fstab->recs[i].fs_mgr_flags & MF_VERIFY)) {
-            int rc = fs_mgr_setup_verity(&fstab->recs[i], true);
+        } else if (fstab_entry.fs_mgr_flags.verify) {
+            int rc = fs_mgr_setup_verity(&fstab_entry, true);
             if (__android_log_is_debuggable() &&
                     (rc == FS_MGR_SETUP_VERITY_DISABLED ||
                      rc == FS_MGR_SETUP_VERITY_SKIPPED)) {
@@ -1322,15 +1280,15 @@
             }
         }
 
-        /* Now mount it where requested */
+        // Now mount it where requested */
         if (tmp_mount_point) {
             mount_point = tmp_mount_point;
         } else {
-            mount_point = fstab->recs[i].mount_point;
+            mount_point = fstab_entry.mount_point;
         }
         int retry_count = 2;
         while (retry_count-- > 0) {
-            if (!__mount(n_blk_device, mount_point, &fstab->recs[i])) {
+            if (!__mount(n_blk_device, mount_point, fstab_entry)) {
                 fs_stat &= ~FS_STAT_FULL_MOUNT_FAILED;
                 return FS_MGR_DOMNT_SUCCESS;
             } else {
@@ -1339,10 +1297,10 @@
                 mount_errors++;
                 fs_stat |= FS_STAT_FULL_MOUNT_FAILED;
                 // try again after fsck
-                check_fs(n_blk_device, fstab->recs[i].fs_type, fstab->recs[i].mount_point, &fs_stat);
+                check_fs(n_blk_device, fstab_entry.fs_type, fstab_entry.mount_point, &fs_stat);
             }
         }
-        log_fs_stat(fstab->recs[i].blk_device, fs_stat);
+        log_fs_stat(fstab_entry.blk_device, fs_stat);
     }
 
     // Reach here means the mount attempt fails.
@@ -1350,19 +1308,22 @@
         PERROR << "Cannot mount filesystem on " << n_blk_device << " at " << mount_point;
         if (first_mount_errno == EBUSY) return FS_MGR_DOMNT_BUSY;
     } else {
-        /* We didn't find a match, say so and return an error */
+        // We didn't find a match, say so and return an error.
         LERROR << "Cannot find mount point " << n_name << " in fstab";
     }
     return FS_MGR_DOMNT_FAILED;
 }
 
 int fs_mgr_do_mount(fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point) {
-    return fs_mgr_do_mount_helper(fstab, n_name, n_blk_device, tmp_mount_point, -1);
+    auto new_fstab = LegacyFstabToFstab(fstab);
+    return fs_mgr_do_mount_helper(&new_fstab, n_name, n_blk_device, tmp_mount_point, -1);
 }
 
 int fs_mgr_do_mount(fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point,
                     bool needs_checkpoint) {
-    return fs_mgr_do_mount_helper(fstab, n_name, n_blk_device, tmp_mount_point, needs_checkpoint);
+    auto new_fstab = LegacyFstabToFstab(fstab);
+    return fs_mgr_do_mount_helper(&new_fstab, n_name, n_blk_device, tmp_mount_point,
+                                  needs_checkpoint);
 }
 
 /*
@@ -1505,23 +1466,22 @@
      * logging mode, in which case return that */
     *mode = VERITY_MODE_DEFAULT;
 
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
-                                                               fs_mgr_free_fstab);
-    if (!fstab) {
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
         LERROR << "Failed to read default fstab";
         return false;
     }
 
-    for (int i = 0; i < fstab->num_entries; i++) {
-        if (fs_mgr_is_avb(&fstab->recs[i])) {
+    for (const auto& entry : fstab) {
+        if (entry.fs_mgr_flags.avb) {
             *mode = VERITY_MODE_RESTART;  // avb only supports restart mode.
             break;
-        } else if (!fs_mgr_is_verified(&fstab->recs[i])) {
+        } else if (!entry.fs_mgr_flags.verify) {
             continue;
         }
 
         int current;
-        if (load_verity_state(&fstab->recs[i], &current) < 0) {
+        if (load_verity_state(entry, &current) < 0) {
             continue;
         }
         if (current != VERITY_MODE_DEFAULT) {
@@ -1533,7 +1493,8 @@
     return true;
 }
 
-bool fs_mgr_update_verity_state(std::function<fs_mgr_verity_state_callback> callback) {
+bool fs_mgr_update_verity_state(
+        std::function<void(const std::string& mount_point, int mode)> callback) {
     if (!callback) {
         return false;
     }
@@ -1543,27 +1504,25 @@
         return false;
     }
 
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
-                                                               fs_mgr_free_fstab);
-    if (!fstab) {
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
         LERROR << "Failed to read default fstab";
         return false;
     }
 
     DeviceMapper& dm = DeviceMapper::Instance();
 
-    for (int i = 0; i < fstab->num_entries; i++) {
-        auto fsrec = &fstab->recs[i];
-        if (!fs_mgr_is_verified(fsrec) && !fs_mgr_is_avb(fsrec)) {
+    for (const auto& entry : fstab) {
+        if (!entry.fs_mgr_flags.verify && !entry.fs_mgr_flags.avb) {
             continue;
         }
 
         std::string mount_point;
-        if (!strcmp(fsrec->mount_point, "/")) {
+        if (entry.mount_point == "/") {
             // In AVB, the dm device name is vroot instead of system.
-            mount_point = fs_mgr_is_avb(fsrec) ? "vroot" : "system";
+            mount_point = entry.fs_mgr_flags.avb ? "vroot" : "system";
         } else {
-            mount_point = basename(fsrec->mount_point);
+            mount_point = basename(entry.mount_point.c_str());
         }
 
         if (dm.GetState(mount_point) == DmDeviceState::INVALID) {
@@ -1574,7 +1533,7 @@
         const char* status;
         std::vector<DeviceMapper::TargetInfo> table;
         if (!dm.GetTableStatus(mount_point, &table) || table.empty() || table[0].data.empty()) {
-            if (!fs_mgr_is_verifyatboot(fsrec)) {
+            if (!entry.fs_mgr_flags.verify_at_boot) {
                 PERROR << "Failed to query DM_TABLE_STATUS for " << mount_point;
                 continue;
             }
@@ -1588,7 +1547,7 @@
         // instead of [partition.vroot.verified].
         if (mount_point == "vroot") mount_point = "system";
         if (*status == 'C' || *status == 'V') {
-            callback(fsrec, mount_point.c_str(), mode, *status);
+            callback(mount_point, mode);
         }
     }
 
diff --git a/fs_mgr/fs_mgr_boot_config.cpp b/fs_mgr/fs_mgr_boot_config.cpp
index 733ad55..abece4d 100644
--- a/fs_mgr/fs_mgr_boot_config.cpp
+++ b/fs_mgr/fs_mgr_boot_config.cpp
@@ -81,6 +81,9 @@
 bool fs_mgr_get_boot_config_from_kernel_cmdline(const std::string& key, std::string* out_val) {
     std::string cmdline;
     if (!android::base::ReadFileToString("/proc/cmdline", &cmdline)) return false;
+    if (!cmdline.empty() && cmdline.back() == '\n') {
+        cmdline.pop_back();
+    }
     return fs_mgr_get_boot_config_from_kernel(cmdline, key, out_val);
 }
 
diff --git a/fs_mgr/fs_mgr_format.cpp b/fs_mgr/fs_mgr_format.cpp
index 0983663..1a0e7ab 100644
--- a/fs_mgr/fs_mgr_format.cpp
+++ b/fs_mgr/fs_mgr_format.cpp
@@ -24,6 +24,7 @@
 #include <cutils/partition_utils.h>
 #include <sys/mount.h>
 
+#include <android-base/unique_fd.h>
 #include <ext4_utils/ext4.h>
 #include <ext4_utils/ext4_utils.h>
 #include <logwrap/logwrap.h>
@@ -34,30 +35,28 @@
 #include "fs_mgr_priv.h"
 #include "cryptfs.h"
 
-static int get_dev_sz(char *fs_blkdev, uint64_t *dev_sz)
-{
-    int fd;
+using android::base::unique_fd;
 
-    if ((fd = open(fs_blkdev, O_RDONLY)) < 0) {
+static int get_dev_sz(const std::string& fs_blkdev, uint64_t* dev_sz) {
+    unique_fd fd(TEMP_FAILURE_RETRY(open(fs_blkdev.c_str(), O_RDONLY | O_CLOEXEC)));
+
+    if (fd < 0) {
         PERROR << "Cannot open block device";
         return -1;
     }
 
     if ((ioctl(fd, BLKGETSIZE64, dev_sz)) == -1) {
         PERROR << "Cannot get block device size";
-        close(fd);
         return -1;
     }
 
-    close(fd);
     return 0;
 }
 
-static int format_ext4(char *fs_blkdev, char *fs_mnt_point, bool crypt_footer)
-{
+static int format_ext4(const std::string& fs_blkdev, const std::string& fs_mnt_point,
+                       bool crypt_footer) {
     uint64_t dev_sz;
     int rc = 0;
-    int status;
 
     rc = get_dev_sz(fs_blkdev, &dev_sz);
     if (rc) {
@@ -71,7 +70,8 @@
 
     std::string size_str = std::to_string(dev_sz / 4096);
     const char* const mke2fs_args[] = {
-        "/system/bin/mke2fs", "-t", "ext4", "-b", "4096", fs_blkdev, size_str.c_str(), nullptr};
+            "/system/bin/mke2fs", "-t",   "ext4", "-b", "4096", fs_blkdev.c_str(),
+            size_str.c_str(),     nullptr};
 
     rc = android_fork_execvp_ext(arraysize(mke2fs_args), const_cast<char**>(mke2fs_args), NULL,
                                  true, LOG_KLOG, true, nullptr, nullptr, 0);
@@ -81,12 +81,7 @@
     }
 
     const char* const e2fsdroid_args[] = {
-        "/system/bin/e2fsdroid",
-        "-e",
-        "-a",
-        fs_mnt_point,
-        fs_blkdev,
-        nullptr};
+            "/system/bin/e2fsdroid", "-e", "-a", fs_mnt_point.c_str(), fs_blkdev.c_str(), nullptr};
 
     rc = android_fork_execvp_ext(arraysize(e2fsdroid_args), const_cast<char**>(e2fsdroid_args),
                                  NULL, true, LOG_KLOG, true, nullptr, nullptr, 0);
@@ -97,10 +92,7 @@
     return rc;
 }
 
-static int format_f2fs(char *fs_blkdev, uint64_t dev_sz, bool crypt_footer)
-{
-    int status;
-
+static int format_f2fs(const std::string& fs_blkdev, uint64_t dev_sz, bool crypt_footer) {
     if (!dev_sz) {
         int rc = get_dev_sz(fs_blkdev, &dev_sz);
         if (rc) {
@@ -118,7 +110,7 @@
     const char* const args[] = {
         "/system/bin/make_f2fs",
         "-g", "android",
-        fs_blkdev,
+        fs_blkdev.c_str(),
         size_str.c_str(),
         nullptr
     };
@@ -128,20 +120,21 @@
                                    LOG_KLOG, true, nullptr, nullptr, 0);
 }
 
-int fs_mgr_do_format(struct fstab_rec *fstab, bool crypt_footer)
-{
-    int rc = -EINVAL;
+int fs_mgr_do_format(const FstabEntry& entry, bool crypt_footer) {
+    LERROR << __FUNCTION__ << ": Format " << entry.blk_device << " as '" << entry.fs_type << "'";
 
-    LERROR << __FUNCTION__ << ": Format " << fstab->blk_device
-           << " as '" << fstab->fs_type << "'";
-
-    if (!strncmp(fstab->fs_type, "f2fs", 4)) {
-        rc = format_f2fs(fstab->blk_device, fstab->length, crypt_footer);
-    } else if (!strncmp(fstab->fs_type, "ext4", 4)) {
-        rc = format_ext4(fstab->blk_device, fstab->mount_point, crypt_footer);
+    if (entry.fs_type == "f2fs") {
+        return format_f2fs(entry.blk_device, entry.length, crypt_footer);
+    } else if (entry.fs_type == "ext4") {
+        return format_ext4(entry.blk_device, entry.mount_point, crypt_footer);
     } else {
-        LERROR << "File system type '" << fstab->fs_type << "' is not supported";
+        LERROR << "File system type '" << entry.fs_type << "' is not supported";
+        return -EINVAL;
     }
+}
 
-    return rc;
+int fs_mgr_do_format(struct fstab_rec* rec, bool crypt_footer) {
+    auto entry = FstabRecToFstabEntry(rec);
+
+    return fs_mgr_do_format(entry, crypt_footer);
 }
diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index 0fde22e..e0891eb 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -33,6 +33,7 @@
 
 #include "fs_mgr_priv.h"
 
+using android::base::Split;
 using android::base::StartsWith;
 
 const std::string kDefaultAndroidDtDir("/proc/device-tree/firmware/android");
@@ -53,11 +54,12 @@
     int file_names_mode = 0;
     off64_t erase_blk_size = 0;
     off64_t logical_blk_size = 0;
+    std::string vbmeta_partition;
 };
 
 struct flag_list {
     const char *name;
-    unsigned int flag;
+    uint64_t flag;
 };
 
 static struct flag_list mount_flags[] = {
@@ -97,6 +99,7 @@
         {"verifyatboot", MF_VERIFYATBOOT},
         {"verify", MF_VERIFY},
         {"avb", MF_AVB},
+        {"avb=", MF_AVB},
         {"noemulatedsd", MF_NOEMULATEDSD},
         {"notrim", MF_NOTRIM},
         {"formattable", MF_FORMATTABLE},
@@ -113,6 +116,7 @@
         {"logical", MF_LOGICAL},
         {"checkpoint=block", MF_CHECKPOINT_BLK},
         {"checkpoint=fs", MF_CHECKPOINT_FS},
+        {"slotselect_other", MF_SLOTSELECT_OTHER},
         {0, 0},
 };
 
@@ -120,9 +124,11 @@
 #define EM_ICE          2
 #define EM_AES_256_CTS  3
 #define EM_AES_256_HEH  4
+#define EM_ADIANTUM     5
 
 static const struct flag_list file_contents_encryption_modes[] = {
     {"aes-256-xts", EM_AES_256_XTS},
+    {"adiantum", EM_ADIANTUM},
     {"software", EM_AES_256_XTS}, /* alias for backwards compatibility */
     {"ice", EM_ICE}, /* hardware-specific inline cryptographic engine */
     {0, 0},
@@ -131,6 +137,7 @@
 static const struct flag_list file_names_encryption_modes[] = {
     {"aes-256-cts", EM_AES_256_CTS},
     {"aes-256-heh", EM_AES_256_HEH},
+    {"adiantum", EM_ADIANTUM},
     {0, 0},
 };
 
@@ -147,7 +154,7 @@
     return 0;
 }
 
-static const char* flag_to_encryption_mode(const struct flag_list* list, int flag) {
+static const char* flag_to_encryption_mode(const struct flag_list* list, uint64_t flag) {
     const struct flag_list *j;
 
     for (j = list; j->name; ++j) {
@@ -201,11 +208,9 @@
     return false;
 }
 
-static int parse_flags(char *flags, struct flag_list *fl,
-                       struct fs_mgr_flag_values *flag_vals,
-                       char *fs_options, int fs_options_len)
-{
-    int f = 0;
+static uint64_t parse_flags(char* flags, struct flag_list* fl, struct fs_mgr_flag_values* flag_vals,
+                            char* fs_options, int fs_options_len) {
+    uint64_t f = 0;
     int i;
     char *p;
     char *savep;
@@ -271,6 +276,8 @@
                         flag_vals->file_names_mode =
                             encryption_mode_to_flag(file_names_encryption_modes,
                                                     colon + 1, "file names");
+                    } else if (flag_vals->file_contents_mode == EM_ADIANTUM) {
+                        flag_vals->file_names_mode = EM_ADIANTUM;
                     } else {
                         flag_vals->file_names_mode = EM_AES_256_CTS;
                     }
@@ -309,6 +316,8 @@
                     flag_vals->swap_prio = strtoll(arg, NULL, 0);
                 } else if (flag == MF_MAX_COMP_STREAMS) {
                     flag_vals->max_comp_streams = strtoll(arg, NULL, 0);
+                } else if (flag == MF_AVB) {
+                    flag_vals->vbmeta_partition = arg;
                 } else if (flag == MF_ZRAMSIZE) {
                     auto is_percent = !!strrchr(arg, '%');
                     auto val = strtoll(arg, NULL, 0);
@@ -578,6 +587,7 @@
         entry.erase_blk_size = flag_vals.erase_blk_size;
         entry.logical_blk_size = flag_vals.logical_blk_size;
         entry.sysfs_path = std::move(flag_vals.sysfs_path);
+        entry.vbmeta_partition = std::move(flag_vals.vbmeta_partition);
         if (entry.fs_mgr_flags.logical) {
             entry.logical_partition_name = entry.blk_device;
         }
@@ -840,11 +850,12 @@
 }
 
 std::set<std::string> fs_mgr_get_boot_devices() {
-    // boot_devices can be specified in device tree.
-    std::string dt_value;
-    std::string file_name = get_android_dt_dir() + "/boot_devices";
-    if (read_dt_file(file_name, &dt_value)) {
-        auto boot_devices = android::base::Split(dt_value, ",");
+    // First check the kernel commandline, then try the device tree otherwise
+    std::string dt_file_name = get_android_dt_dir() + "/boot_devices";
+    std::string value;
+    if (fs_mgr_get_boot_config_from_kernel_cmdline("boot_devices", &value) ||
+        read_dt_file(dt_file_name, &value)) {
+        auto boot_devices = Split(value, ",");
         return std::set<std::string>(boot_devices.begin(), boot_devices.end());
     }
 
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index 649c8bf..8bfcd81 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -70,19 +70,11 @@
 
 #if ALLOW_ADBD_DISABLE_VERITY == 0  // If we are a user build, provide stubs
 
-bool fs_mgr_overlayfs_mount_all(fstab*) {
+bool fs_mgr_overlayfs_mount_all(Fstab*) {
     return false;
 }
 
-bool fs_mgr_overlayfs_mount_all(const std::vector<fstab_rec*>&) {
-    return false;
-}
-
-std::vector<std::string> fs_mgr_overlayfs_required_devices(fstab*) {
-    return {};
-}
-
-std::vector<std::string> fs_mgr_overlayfs_required_devices(const std::vector<fstab_rec*>&) {
+std::vector<std::string> fs_mgr_overlayfs_required_devices(Fstab*) {
     return {};
 }
 
@@ -131,28 +123,31 @@
 
 // At less than 1% free space return value of false,
 // means we will try to wrap with overlayfs.
-bool fs_mgr_filesystem_has_space(const char* mount_point) {
+bool fs_mgr_filesystem_has_space(const std::string& mount_point) {
     // If we have access issues to find out space remaining, return true
     // to prevent us trying to override with overlayfs.
     struct statvfs vst;
-    if (statvfs(mount_point, &vst)) return true;
+    if (statvfs(mount_point.c_str(), &vst)) return true;
 
     static constexpr int kPercentThreshold = 1;  // 1%
 
     return (vst.f_bfree >= (vst.f_blocks * kPercentThreshold / 100));
 }
 
-bool fs_mgr_overlayfs_enabled(struct fstab_rec* fsrec) {
+bool fs_mgr_overlayfs_enabled(FstabEntry* entry) {
     // readonly filesystem, can not be mount -o remount,rw
     // if squashfs or if free space is (near) zero making such a remount
     // virtually useless, or if there are shared blocks that prevent remount,rw
-    if (("squashfs"s == fsrec->fs_type) || !fs_mgr_filesystem_has_space(fsrec->mount_point)) {
+    if ("squashfs" == entry->fs_type || !fs_mgr_filesystem_has_space(entry->mount_point)) {
         return true;
     }
-    if (fs_mgr_is_logical(fsrec)) {
-        fs_mgr_update_logical_partition(fsrec);
+    if (entry->fs_mgr_flags.logical) {
+        fs_mgr_update_logical_partition(entry);
     }
-    return fs_mgr_has_shared_blocks(fsrec->mount_point, fsrec->blk_device);
+    auto save_errno = errno;
+    auto has_shared_blocks = fs_mgr_has_shared_blocks(entry->mount_point, entry->blk_device);
+    errno = save_errno;
+    return has_shared_blocks;
 }
 
 bool fs_mgr_rm_all(const std::string& path, bool* change = nullptr, int level = 0) {
@@ -250,22 +245,16 @@
 }
 
 bool fs_mgr_overlayfs_already_mounted(const std::string& mount_point, bool overlay_only = true) {
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab("/proc/mounts"),
-                                                               fs_mgr_free_fstab);
-    if (!fstab) return false;
+    Fstab fstab;
+    if (!ReadFstabFromFile("/proc/mounts", &fstab)) {
+        return false;
+    }
     const auto lowerdir = kLowerdirOption + mount_point;
-    for (auto i = 0; i < fstab->num_entries; ++i) {
-        const auto fsrec = &fstab->recs[i];
-        const auto fs_type = fsrec->fs_type;
-        if (!fs_type) continue;
-        if (overlay_only && ("overlay"s != fs_type) && ("overlayfs"s != fs_type)) continue;
-        auto fsrec_mount_point = fsrec->mount_point;
-        if (!fsrec_mount_point) continue;
-        if (mount_point != fsrec_mount_point) continue;
+    for (const auto& entry : fstab) {
+        if (overlay_only && "overlay" != entry.fs_type && "overlayfs" != entry.fs_type) continue;
+        if (mount_point != entry.mount_point) continue;
         if (!overlay_only) return true;
-        const auto fs_options = fsrec->fs_options;
-        if (!fs_options) continue;
-        const auto options = android::base::Split(fs_options, ",");
+        const auto options = android::base::Split(entry.fs_options, ",");
         for (const auto& opt : options) {
             if (opt == lowerdir) {
                 return true;
@@ -277,34 +266,27 @@
 
 std::vector<std::string> fs_mgr_overlayfs_verity_enabled_list() {
     std::vector<std::string> ret;
-    fs_mgr_update_verity_state([&ret](fstab_rec*, const char* mount_point, int, int) {
-        ret.emplace_back(mount_point);
-    });
+    auto save_errno = errno;
+    fs_mgr_update_verity_state(
+            [&ret](const std::string& mount_point, int) { ret.emplace_back(mount_point); });
+    if ((errno == ENOENT) || (errno == ENXIO)) errno = save_errno;
     return ret;
 }
 
-bool fs_mgr_wants_overlayfs(fstab_rec* fsrec) {
-    if (!fsrec) return false;
-
-    auto fsrec_mount_point = fsrec->mount_point;
-    if (!fsrec_mount_point || !fsrec_mount_point[0]) return false;
-    if (!fsrec->blk_device) return false;
-
-    if (!fsrec->fs_type) return false;
-
+bool fs_mgr_wants_overlayfs(FstabEntry* entry) {
     // Don't check entries that are managed by vold.
-    if (fsrec->fs_mgr_flags & (MF_VOLDMANAGED | MF_RECOVERYONLY)) return false;
+    if (entry->fs_mgr_flags.vold_managed || entry->fs_mgr_flags.recovery_only) return false;
 
     // Only concerned with readonly partitions.
-    if (!(fsrec->flags & MS_RDONLY)) return false;
+    if (!(entry->flags & MS_RDONLY)) return false;
 
     // If unbindable, do not allow overlayfs as this could expose us to
     // security issues.  On Android, this could also be used to turn off
     // the ability to overlay an otherwise acceptable filesystem since
     // /system and /vendor are never bound(sic) to.
-    if (fsrec->flags & MS_UNBINDABLE) return false;
+    if (entry->flags & MS_UNBINDABLE) return false;
 
-    if (!fs_mgr_overlayfs_enabled(fsrec)) return false;
+    if (!fs_mgr_overlayfs_enabled(entry)) return false;
 
     return true;
 }
@@ -392,11 +374,11 @@
     return kPhysicalDevice + fs_mgr_get_super_partition_name(slot_number);
 }
 
-bool fs_mgr_overlayfs_has_logical(const fstab* fstab) {
-    if (!fstab) return false;
-    for (auto i = 0; i < fstab->num_entries; i++) {
-        const auto fsrec = &fstab->recs[i];
-        if (fs_mgr_is_logical(fsrec)) return true;
+bool fs_mgr_overlayfs_has_logical(const Fstab& fstab) {
+    for (const auto& entry : fstab) {
+        if (entry.fs_mgr_flags.logical) {
+            return true;
+        }
     }
     return false;
 }
@@ -522,7 +504,7 @@
     // hijack __mount() report format to help triage
     auto report = "__mount(source=overlay,target="s + mount_point + ",type=overlay";
     const auto opt_list = android::base::Split(options, ",");
-    for (const auto opt : opt_list) {
+    for (const auto& opt : opt_list) {
         if (android::base::StartsWith(opt, kUpperdirOption)) {
             report = report + "," + opt;
             break;
@@ -541,15 +523,12 @@
     }
 }
 
-std::vector<std::string> fs_mgr_candidate_list(fstab* fstab, const char* mount_point = nullptr) {
+std::vector<std::string> fs_mgr_candidate_list(Fstab* fstab, const char* mount_point = nullptr) {
     std::vector<std::string> mounts;
-    if (!fstab) return mounts;
-
     auto verity = fs_mgr_overlayfs_verity_enabled_list();
-    for (auto i = 0; i < fstab->num_entries; i++) {
-        const auto fsrec = &fstab->recs[i];
-        if (!fs_mgr_wants_overlayfs(fsrec)) continue;
-        std::string new_mount_point(fs_mgr_mount_point(fsrec->mount_point));
+    for (auto& entry : *fstab) {
+        if (!fs_mgr_wants_overlayfs(&entry)) continue;
+        std::string new_mount_point(fs_mgr_mount_point(entry.mount_point.c_str()));
         if (mount_point && (new_mount_point != mount_point)) continue;
         if (std::find(verity.begin(), verity.end(), android::base::Basename(new_mount_point)) !=
             verity.end()) {
@@ -581,10 +560,9 @@
     if (std::find(verity.begin(), verity.end(), "system") != verity.end()) return mounts;
 
     // confirm that fstab is missing system
-    if (fs_mgr_get_entry_for_mount_point(const_cast<struct fstab*>(fstab), "/")) {
-        return mounts;
-    }
-    if (fs_mgr_get_entry_for_mount_point(const_cast<struct fstab*>(fstab), "/system")) {
+    if (std::find_if(fstab->begin(), fstab->end(), [](const auto& entry) {
+            return entry.mount_point == "/" || entry.mount_point == "/system ";
+        }) != fstab->end()) {
         return mounts;
     }
 
@@ -606,26 +584,20 @@
         PERROR << "create " << kScratchMountPoint;
     }
 
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> local_fstab(
-            static_cast<fstab*>(calloc(1, sizeof(fstab))), fs_mgr_free_fstab);
-    auto fsrec = static_cast<fstab_rec*>(calloc(1, sizeof(fstab_rec)));
-    local_fstab->num_entries = 1;
-    local_fstab->recs = fsrec;
-    fsrec->blk_device = strdup(device_path.c_str());
-    fsrec->mount_point = strdup(kScratchMountPoint.c_str());
-    fsrec->fs_type = strdup(mnt_type.c_str());
-    fsrec->flags = MS_RELATIME;
-    fsrec->fs_options = strdup("");
+    FstabEntry entry;
+    entry.blk_device = device_path;
+    entry.mount_point = kScratchMountPoint;
+    entry.fs_type = mnt_type;
+    entry.flags = MS_RELATIME;
     auto save_errno = errno;
-    auto mounted = fs_mgr_do_mount_one(fsrec) == 0;
+    auto mounted = fs_mgr_do_mount_one(entry) == 0;
     if (!mounted) {
-        free(fsrec->fs_type);
         if (mnt_type == "f2fs") {
-            fsrec->fs_type = strdup("ext4");
+            entry.fs_type = "ext4";
         } else {
-            fsrec->fs_type = strdup("f2fs");
+            entry.fs_type = "f2fs";
         }
-        mounted = fs_mgr_do_mount_one(fsrec) == 0;
+        mounted = fs_mgr_do_mount_one(entry) == 0;
         if (!mounted) save_errno = errno;
     }
     setfscreatecon(nullptr);
@@ -682,7 +654,7 @@
     return true;
 }
 
-bool fs_mgr_overlayfs_create_scratch(const fstab* fstab, std::string* scratch_device,
+bool fs_mgr_overlayfs_create_scratch(const Fstab& fstab, std::string* scratch_device,
                                      bool* partition_exists, bool* change) {
     *scratch_device = fs_mgr_overlayfs_scratch_device();
     *partition_exists = fs_mgr_rw_access(*scratch_device);
@@ -766,7 +738,7 @@
 }
 
 // Create and mount kScratchMountPoint storage if we have logical partitions
-bool fs_mgr_overlayfs_setup_scratch(const fstab* fstab, bool* change) {
+bool fs_mgr_overlayfs_setup_scratch(const Fstab& fstab, bool* change) {
     if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) return true;
 
     std::string scratch_device;
@@ -806,20 +778,20 @@
     return builder->FindPartition(android::base::Basename(kScratchMountPoint)) != nullptr;
 }
 
-bool fs_mgr_overlayfs_invalid(const fstab* fstab) {
+bool fs_mgr_overlayfs_invalid() {
     if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) return true;
 
     // in recovery or fastbootd mode, not allowed!
     if (fs_mgr_access("/system/bin/recovery")) return true;
 
-    return !fstab;
+    return false;
 }
 
 }  // namespace
 
-bool fs_mgr_overlayfs_mount_all(fstab* fstab) {
+bool fs_mgr_overlayfs_mount_all(Fstab* fstab) {
     auto ret = false;
-    if (fs_mgr_overlayfs_invalid(fstab)) return ret;
+    if (fs_mgr_overlayfs_invalid()) return ret;
 
     auto scratch_can_be_mounted = true;
     for (const auto& mount_point : fs_mgr_candidate_list(fstab)) {
@@ -840,17 +812,12 @@
     return ret;
 }
 
-bool fs_mgr_overlayfs_mount_all(const std::vector<fstab_rec*>& fsrecs) {
-    std::vector<fstab_rec> recs;
-    for (const auto& rec : fsrecs) recs.push_back(*rec);
-    fstab fstab = {static_cast<int>(fsrecs.size()), &recs[0]};
-    return fs_mgr_overlayfs_mount_all(&fstab);
-}
+std::vector<std::string> fs_mgr_overlayfs_required_devices(Fstab* fstab) {
+    if (fs_mgr_overlayfs_invalid()) return {};
 
-std::vector<std::string> fs_mgr_overlayfs_required_devices(fstab* fstab) {
-    if (fs_mgr_overlayfs_invalid(fstab)) return {};
-
-    if (fs_mgr_get_entry_for_mount_point(fstab, kScratchMountPoint)) {
+    if (std::find_if(fstab->begin(), fstab->end(), [](const auto& entry) {
+            return entry.mount_point == kScratchMountPoint;
+        }) != fstab->end()) {
         return {};
     }
 
@@ -863,13 +830,6 @@
     return {};
 }
 
-std::vector<std::string> fs_mgr_overlayfs_required_devices(const std::vector<fstab_rec*>& fsrecs) {
-    std::vector<fstab_rec> recs;
-    for (const auto& rec : fsrecs) recs.push_back(*rec);
-    fstab fstab = {static_cast<int>(fsrecs.size()), &recs[0]};
-    return fs_mgr_overlayfs_required_devices(&fstab);
-}
-
 // Returns false if setup not permitted, errno set to last error.
 // If something is altered, set *change.
 bool fs_mgr_overlayfs_setup(const char* backing, const char* mount_point, bool* change) {
@@ -882,10 +842,13 @@
         return ret;
     }
 
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
-                                                               fs_mgr_free_fstab);
-    if (!fstab) return ret;
-    auto mounts = fs_mgr_candidate_list(fstab.get(), fs_mgr_mount_point(mount_point));
+    auto save_errno = errno;
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
+        return false;
+    }
+    errno = save_errno;
+    auto mounts = fs_mgr_candidate_list(&fstab, fs_mgr_mount_point(mount_point));
     if (mounts.empty()) return ret;
 
     std::string dir;
@@ -893,18 +856,23 @@
         if (backing && backing[0] && (overlay_mount_point != backing)) continue;
         if (overlay_mount_point == kScratchMountPoint) {
             if (!fs_mgr_rw_access(fs_mgr_overlayfs_super_device(fs_mgr_overlayfs_slot_number())) ||
-                !fs_mgr_overlayfs_has_logical(fstab.get())) {
+                !fs_mgr_overlayfs_has_logical(fstab)) {
                 continue;
             }
-            if (!fs_mgr_overlayfs_setup_scratch(fstab.get(), change)) continue;
+            if (!fs_mgr_overlayfs_setup_scratch(fstab, change)) continue;
         } else {
-            if (!fs_mgr_get_entry_for_mount_point(fstab.get(), overlay_mount_point)) continue;
+            if (std::find_if(fstab.begin(), fstab.end(), [&overlay_mount_point](const auto& entry) {
+                    return entry.mount_point == overlay_mount_point;
+                }) == fstab.end()) {
+                continue;
+            }
         }
         dir = overlay_mount_point;
         break;
     }
     if (dir.empty()) {
-        errno = ESRCH;
+        if (change && *change) errno = ESRCH;
+        if (errno == EPERM) errno = save_errno;
         return ret;
     }
 
@@ -960,10 +928,12 @@
 
 bool fs_mgr_overlayfs_is_setup() {
     if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) return true;
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
-                                                               fs_mgr_free_fstab);
-    if (fs_mgr_overlayfs_invalid(fstab.get())) return false;
-    for (const auto& mount_point : fs_mgr_candidate_list(fstab.get())) {
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
+        return false;
+    }
+    if (fs_mgr_overlayfs_invalid()) return false;
+    for (const auto& mount_point : fs_mgr_candidate_list(&fstab)) {
         if (fs_mgr_overlayfs_already_mounted(mount_point)) return true;
     }
     return false;
diff --git a/fs_mgr/fs_mgr_priv.h b/fs_mgr/fs_mgr_priv.h
index faef34b..7d1159b 100644
--- a/fs_mgr/fs_mgr_priv.h
+++ b/fs_mgr/fs_mgr_priv.h
@@ -120,6 +120,8 @@
 #define MF_CHECKPOINT_FS  0x40000000
 #define MF_FIRST_STAGE_MOUNT \
                           0x80000000
+#define MF_SLOTSELECT_OTHER  \
+                         0x100000000
 // clang-format on
 
 #define DM_BUF_SIZE 4096
@@ -137,6 +139,6 @@
 bool fs_mgr_is_device_unlocked();
 const std::string& get_android_dt_dir();
 bool is_dt_compatible();
-int load_verity_state(fstab_rec* fstab, int* mode);
+int load_verity_state(const FstabEntry& entry, int* mode);
 
 #endif /* __CORE_FS_MGR_PRIV_H */
diff --git a/fs_mgr/fs_mgr_roots.cpp b/fs_mgr/fs_mgr_roots.cpp
new file mode 100644
index 0000000..f44ff41
--- /dev/null
+++ b/fs_mgr/fs_mgr_roots.cpp
@@ -0,0 +1,195 @@
+/*
+ * Copyright (C) 2018 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 "fs_mgr/roots.h"
+
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <string>
+
+#include "fs_mgr.h"
+#include "fs_mgr_dm_linear.h"
+#include "fs_mgr_priv.h"
+
+namespace android {
+namespace fs_mgr {
+
+static constexpr const char* kSystemRoot = "/system";
+
+static bool gDidMapLogicalPartitions = false;
+
+FstabEntry* GetEntryForPath(Fstab* fstab, const std::string& path) {
+    if (path.empty()) return nullptr;
+    std::string str(path);
+    while (true) {
+        auto it = std::find_if(fstab->begin(), fstab->end(),
+                               [&str](const auto& entry) { return entry.mount_point == str; });
+        if (it != fstab->end()) return &*it;
+        if (str == "/") break;
+        auto slash = str.find_last_of('/');
+        if (slash == std::string::npos) break;
+        if (slash == 0) {
+            str = "/";
+        } else {
+            str = str.substr(0, slash);
+        }
+    }
+    return nullptr;
+}
+
+enum class MountState {
+    ERROR = -1,
+    NOT_MOUNTED = 0,
+    MOUNTED = 1,
+};
+
+static MountState GetMountState(const std::string& mount_point) {
+    Fstab mounted_fstab;
+    if (!ReadFstabFromFile("/proc/mounts", &mounted_fstab)) {
+        LERROR << "Failed to scan mounted volumes";
+        return MountState::ERROR;
+    }
+
+    auto mv = std::find_if(
+            mounted_fstab.begin(), mounted_fstab.end(),
+            [&mount_point](const auto& entry) { return entry.mount_point == mount_point; });
+    if (mv != mounted_fstab.end()) {
+        return MountState::MOUNTED;
+    }
+    return MountState::NOT_MOUNTED;
+}
+
+bool EnsurePathMounted(Fstab* fstab, const std::string& path, const std::string& mount_pt) {
+    auto rec = GetEntryForPath(fstab, path);
+    if (rec == nullptr) {
+        LERROR << "unknown volume for path [" << path << "]";
+        return false;
+    }
+    if (rec->fs_type == "ramdisk") {
+        // The ramdisk is always mounted.
+        return true;
+    }
+
+    // If we can't acquire the block device for a logical partition, it likely
+    // was never created. In that case we try to create it.
+    if (rec->fs_mgr_flags.logical && !fs_mgr_update_logical_partition(rec)) {
+        if (gDidMapLogicalPartitions) {
+            LERROR << "Failed to find block device for partition";
+            return false;
+        }
+        std::string super_name = fs_mgr_get_super_partition_name();
+        if (!android::fs_mgr::CreateLogicalPartitions("/dev/block/by-name/" + super_name)) {
+            LERROR << "Failed to create logical partitions";
+            return false;
+        }
+        gDidMapLogicalPartitions = true;
+        if (!fs_mgr_update_logical_partition(rec)) {
+            LERROR << "Failed to find block device for partition";
+            return false;
+        }
+    }
+
+    auto mounted = GetMountState(rec->mount_point);
+    if (mounted == MountState::ERROR) {
+        return false;
+    }
+    if (mounted == MountState::MOUNTED) {
+        return true;
+    }
+
+    const std::string mount_point = mount_pt.empty() ? rec->mount_point : mount_pt;
+
+    static const std::vector<std::string> supported_fs{"ext4", "squashfs", "vfat", "f2fs"};
+    if (std::find(supported_fs.begin(), supported_fs.end(), rec->fs_type) == supported_fs.end()) {
+        LERROR << "unknown fs_type \"" << rec->fs_type << "\" for " << mount_point;
+        return false;
+    }
+
+    int result = fs_mgr_do_mount_one(*rec, mount_point);
+    if (result == -1 && rec->fs_mgr_flags.formattable) {
+        PERROR << "Failed to mount " << mount_point << "; formatting";
+        bool crypt_footer = rec->is_encryptable() && rec->key_loc == "footer";
+        if (fs_mgr_do_format(*rec, crypt_footer) != 0) {
+            PERROR << "Failed to format " << mount_point;
+            return false;
+        }
+        result = fs_mgr_do_mount_one(*rec, mount_point);
+    }
+
+    if (result == -1) {
+        PERROR << "Failed to mount " << mount_point;
+        return false;
+    }
+    return true;
+}
+
+bool EnsurePathUnmounted(Fstab* fstab, const std::string& path) {
+    auto rec = GetEntryForPath(fstab, path);
+    if (rec == nullptr) {
+        LERROR << "unknown volume for path [" << path << "]";
+        return false;
+    }
+    if (rec->fs_type == "ramdisk") {
+        // The ramdisk is always mounted; you can't unmount it.
+        return false;
+    }
+
+    Fstab mounted_fstab;
+    if (!ReadFstabFromFile("/proc/mounts", &mounted_fstab)) {
+        LERROR << "Failed to scan mounted volumes";
+        return false;
+    }
+
+    auto mounted = GetMountState(rec->mount_point);
+    if (mounted == MountState::ERROR) {
+        return false;
+    }
+    if (mounted == MountState::NOT_MOUNTED) {
+        return true;
+    }
+
+    int result = umount(rec->mount_point.c_str());
+    if (result == -1) {
+        PWARNING << "Failed to umount " << rec->mount_point;
+        return false;
+    }
+    return true;
+}
+
+std::string GetSystemRoot() {
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
+        LERROR << "Failed to read default fstab";
+        return "";
+    }
+
+    auto it = std::find_if(fstab.begin(), fstab.end(),
+                           [](const auto& entry) { return entry.mount_point == kSystemRoot; });
+    if (it == fstab.end()) {
+        return "/";
+    }
+
+    return kSystemRoot;
+}
+
+bool LogicalPartitionsMapped() {
+    return gDidMapLogicalPartitions;
+}
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/fs_mgr_slotselect.cpp b/fs_mgr/fs_mgr_slotselect.cpp
index 20d60ae..3cb718c 100644
--- a/fs_mgr/fs_mgr_slotselect.cpp
+++ b/fs_mgr/fs_mgr_slotselect.cpp
@@ -21,6 +21,19 @@
 #include "fs_mgr.h"
 #include "fs_mgr_priv.h"
 
+// https://source.android.com/devices/tech/ota/ab/ab_implement#partitions
+// All partitions that are A/B-ed should be named as follows (slots are always
+// named a, b, etc.): boot_a, boot_b, system_a, system_b, vendor_a, vendor_b.
+static std::string other_suffix(const std::string& slot_suffix) {
+    if (slot_suffix == "_a") {
+        return "_b";
+    }
+    if (slot_suffix == "_b") {
+        return "_a";
+    }
+    return "";
+}
+
 // Returns "_a" or "_b" based on androidboot.slot_suffix in kernel cmdline, or an empty string
 // if that parameter does not exist.
 std::string fs_mgr_get_slot_suffix() {
@@ -32,11 +45,10 @@
 
 // Updates |fstab| for slot_suffix. Returns true on success, false on error.
 bool fs_mgr_update_for_slotselect(Fstab* fstab) {
-    int n;
     std::string ab_suffix;
 
     for (auto& entry : *fstab) {
-        if (!entry.fs_mgr_flags.slot_select) {
+        if (!entry.fs_mgr_flags.slot_select && !entry.fs_mgr_flags.slot_select_other) {
             continue;
         }
 
@@ -46,8 +58,10 @@
             if (ab_suffix.empty()) return false;
         }
 
-        entry.blk_device = entry.blk_device + ab_suffix;
-        entry.logical_partition_name = entry.logical_partition_name + ab_suffix;
+        const auto& update_suffix =
+                entry.fs_mgr_flags.slot_select ? ab_suffix : other_suffix(ab_suffix);
+        entry.blk_device = entry.blk_device + update_suffix;
+        entry.logical_partition_name = entry.logical_partition_name + update_suffix;
     }
     return true;
 }
diff --git a/fs_mgr/fs_mgr_verity.cpp b/fs_mgr/fs_mgr_verity.cpp
index 2727a6d..9adf8cc 100644
--- a/fs_mgr/fs_mgr_verity.cpp
+++ b/fs_mgr/fs_mgr_verity.cpp
@@ -536,8 +536,7 @@
     return 0;
 }
 
-static int compare_last_signature(struct fstab_rec *fstab, int *match)
-{
+static int compare_last_signature(const FstabEntry& entry, int* match) {
     char tag[METADATA_TAG_MAX_LENGTH + 1];
     int fd = -1;
     int rc = -1;
@@ -549,42 +548,40 @@
 
     *match = 1;
 
-    if (fec_open(&f, fstab->blk_device, O_RDONLY, FEC_VERITY_DISABLE,
-            FEC_DEFAULT_ROOTS) == -1) {
-        PERROR << "Failed to open '" << fstab->blk_device << "'";
+    if (fec_open(&f, entry.blk_device.c_str(), O_RDONLY, FEC_VERITY_DISABLE, FEC_DEFAULT_ROOTS) ==
+        -1) {
+        PERROR << "Failed to open '" << entry.blk_device << "'";
         return rc;
     }
 
     // read verity metadata
     if (fec_verity_get_metadata(f, &verity) == -1) {
-        PERROR << "Failed to get verity metadata '" << fstab->blk_device << "'";
+        PERROR << "Failed to get verity metadata '" << entry.blk_device << "'";
         goto out;
     }
 
     SHA256(verity.signature, sizeof(verity.signature), curr);
 
-    if (snprintf(tag, sizeof(tag), VERITY_LASTSIG_TAG "_%s",
-            basename(fstab->mount_point)) >= (int)sizeof(tag)) {
-        LERROR << "Metadata tag name too long for " << fstab->mount_point;
+    if (snprintf(tag, sizeof(tag), VERITY_LASTSIG_TAG "_%s", basename(entry.mount_point.c_str())) >=
+        (int)sizeof(tag)) {
+        LERROR << "Metadata tag name too long for " << entry.mount_point;
         goto out;
     }
 
-    if (metadata_find(fstab->verity_loc, tag, SHA256_DIGEST_LENGTH,
-            &offset) < 0) {
+    if (metadata_find(entry.verity_loc.c_str(), tag, SHA256_DIGEST_LENGTH, &offset) < 0) {
         goto out;
     }
 
-    fd = TEMP_FAILURE_RETRY(open(fstab->verity_loc, O_RDWR | O_SYNC | O_CLOEXEC));
+    fd = TEMP_FAILURE_RETRY(open(entry.verity_loc.c_str(), O_RDWR | O_SYNC | O_CLOEXEC));
 
     if (fd == -1) {
-        PERROR << "Failed to open " << fstab->verity_loc;
+        PERROR << "Failed to open " << entry.verity_loc;
         goto out;
     }
 
-    if (TEMP_FAILURE_RETRY(pread64(fd, prev, sizeof(prev),
-            offset)) != sizeof(prev)) {
-        PERROR << "Failed to read " << sizeof(prev) << " bytes from "
-               << fstab->verity_loc << " offset " << offset;
+    if (TEMP_FAILURE_RETRY(pread64(fd, prev, sizeof(prev), offset)) != sizeof(prev)) {
+        PERROR << "Failed to read " << sizeof(prev) << " bytes from " << entry.verity_loc
+               << " offset " << offset;
         goto out;
     }
 
@@ -594,8 +591,8 @@
         /* update current signature hash */
         if (TEMP_FAILURE_RETRY(pwrite64(fd, curr, sizeof(curr),
                 offset)) != sizeof(curr)) {
-            PERROR << "Failed to write " << sizeof(curr) << " bytes to "
-                   << fstab->verity_loc << " offset " << offset;
+            PERROR << "Failed to write " << sizeof(curr) << " bytes to " << entry.verity_loc
+                   << " offset " << offset;
             goto out;
         }
     }
@@ -607,28 +604,23 @@
     return rc;
 }
 
-static int get_verity_state_offset(struct fstab_rec *fstab, off64_t *offset)
-{
+static int get_verity_state_offset(const FstabEntry& entry, off64_t* offset) {
     char tag[METADATA_TAG_MAX_LENGTH + 1];
 
-    if (snprintf(tag, sizeof(tag), VERITY_STATE_TAG "_%s",
-            basename(fstab->mount_point)) >= (int)sizeof(tag)) {
-        LERROR << "Metadata tag name too long for " << fstab->mount_point;
+    if (snprintf(tag, sizeof(tag), VERITY_STATE_TAG "_%s", basename(entry.mount_point.c_str())) >=
+        (int)sizeof(tag)) {
+        LERROR << "Metadata tag name too long for " << entry.mount_point;
         return -1;
     }
 
-    return metadata_find(fstab->verity_loc, tag, sizeof(struct verity_state),
-                offset);
+    return metadata_find(entry.verity_loc.c_str(), tag, sizeof(struct verity_state), offset);
 }
 
-int load_verity_state(struct fstab_rec* fstab, int* mode) {
-    int match = 0;
-    off64_t offset = 0;
-
-    /* unless otherwise specified, use EIO mode */
+int load_verity_state(const FstabEntry& entry, int* mode) {
+    // unless otherwise specified, use EIO mode.
     *mode = VERITY_MODE_EIO;
 
-    /* use the kernel parameter if set */
+    // use the kernel parameter if set.
     std::string veritymode;
     if (fs_mgr_get_boot_config("veritymode", &veritymode)) {
         if (veritymode == "enforcing") {
@@ -637,7 +629,8 @@
         return 0;
     }
 
-    if (get_verity_state_offset(fstab, &offset) < 0) {
+    off64_t offset = 0;
+    if (get_verity_state_offset(entry, &offset) < 0) {
         /* fall back to stateless behavior */
         return 0;
     }
@@ -645,16 +638,17 @@
     if (was_verity_restart()) {
         /* device was restarted after dm-verity detected a corrupted
          * block, so use EIO mode */
-        return write_verity_state(fstab->verity_loc, offset, *mode);
+        return write_verity_state(entry.verity_loc.c_str(), offset, *mode);
     }
 
-    if (!compare_last_signature(fstab, &match) && !match) {
+    int match = 0;
+    if (!compare_last_signature(entry, &match) && !match) {
         /* partition has been reflashed, reset dm-verity state */
         *mode = VERITY_MODE_DEFAULT;
-        return write_verity_state(fstab->verity_loc, offset, *mode);
+        return write_verity_state(entry.verity_loc.c_str(), offset, *mode);
     }
 
-    return read_verity_state(fstab->verity_loc, offset, mode);
+    return read_verity_state(entry.verity_loc.c_str(), offset, mode);
 }
 
 // Update the verity table using the actual block device path.
@@ -716,8 +710,7 @@
 // prepares the verity enabled (MF_VERIFY / MF_VERIFYATBOOT) fstab record for
 // mount. The 'wait_for_verity_dev' parameter makes this function wait for the
 // verity device to get created before return
-int fs_mgr_setup_verity(struct fstab_rec *fstab, bool wait_for_verity_dev)
-{
+int fs_mgr_setup_verity(FstabEntry* entry, bool wait_for_verity_dev) {
     int retval = FS_MGR_SETUP_VERITY_FAIL;
     int fd = -1;
     std::string verity_blk_name;
@@ -725,20 +718,20 @@
     struct fec_verity_metadata verity;
     struct verity_table_params params = { .table = NULL };
 
-    const std::string mount_point(basename(fstab->mount_point));
+    const std::string mount_point(basename(entry->mount_point.c_str()));
     bool verified_at_boot = false;
 
     android::dm::DeviceMapper& dm = android::dm::DeviceMapper::Instance();
 
-    if (fec_open(&f, fstab->blk_device, O_RDONLY, FEC_VERITY_DISABLE,
-            FEC_DEFAULT_ROOTS) < 0) {
-        PERROR << "Failed to open '" << fstab->blk_device << "'";
+    if (fec_open(&f, entry->blk_device.c_str(), O_RDONLY, FEC_VERITY_DISABLE, FEC_DEFAULT_ROOTS) <
+        0) {
+        PERROR << "Failed to open '" << entry->blk_device << "'";
         return retval;
     }
 
     // read verity metadata
     if (fec_verity_get_metadata(f, &verity) < 0) {
-        PERROR << "Failed to get verity metadata '" << fstab->blk_device << "'";
+        PERROR << "Failed to get verity metadata '" << entry->blk_device << "'";
         // Allow verity disabled when the device is unlocked without metadata
         if (fs_mgr_is_device_unlocked()) {
             retval = FS_MGR_SETUP_VERITY_SKIPPED;
@@ -760,9 +753,9 @@
         params.ecc.valid = false;
     }
 
-    params.ecc_dev = fstab->blk_device;
+    params.ecc_dev = entry->blk_device.c_str();
 
-    if (load_verity_state(fstab, &params.mode) < 0) {
+    if (load_verity_state(*entry, &params.mode) < 0) {
         /* if accessing or updating the state failed, switch to the default
          * safe mode. This makes sure the device won't end up in an endless
          * restart loop, and no corrupted data will be exposed to userspace
@@ -803,8 +796,8 @@
           << " (mode " << params.mode << ")";
 
     // Update the verity params using the actual block device path
-    update_verity_table_blk_device(fstab->blk_device, &params.table,
-                                   fstab->fs_mgr_flags & MF_SLOTSELECT);
+    update_verity_table_blk_device(entry->blk_device, &params.table,
+                                   entry->fs_mgr_flags.slot_select);
 
     // load the verity mapping table
     if (load_verity_table(dm, mount_point, verity.data_size, &params, format_verity_table) == 0) {
@@ -848,31 +841,29 @@
     }
 
     // mark the underlying block device as read-only
-    fs_mgr_set_blk_ro(fstab->blk_device);
+    fs_mgr_set_blk_ro(entry->blk_device);
 
     // Verify the entire partition in one go
     // If there is an error, allow it to mount as a normal verity partition.
-    if (fstab->fs_mgr_flags & MF_VERIFYATBOOT) {
-        LINFO << "Verifying partition " << fstab->blk_device << " at boot";
+    if (entry->fs_mgr_flags.verify_at_boot) {
+        LINFO << "Verifying partition " << entry->blk_device << " at boot";
         int err = read_partition(verity_blk_name.c_str(), verity.data_size);
         if (!err) {
-            LINFO << "Verified verity partition "
-                  << fstab->blk_device << " at boot";
+            LINFO << "Verified verity partition " << entry->blk_device << " at boot";
             verified_at_boot = true;
         }
     }
 
     // assign the new verity block device as the block device
     if (!verified_at_boot) {
-        free(fstab->blk_device);
-        fstab->blk_device = strdup(verity_blk_name.c_str());
+        entry->blk_device = verity_blk_name;
     } else if (!dm.DeleteDevice(mount_point)) {
         LERROR << "Failed to remove verity device " << mount_point.c_str();
         goto out;
     }
 
     // make sure we've set everything up properly
-    if (wait_for_verity_dev && !fs_mgr_wait_for_file(fstab->blk_device, 1s)) {
+    if (wait_for_verity_dev && !fs_mgr_wait_for_file(entry->blk_device, 1s)) {
         goto out;
     }
 
diff --git a/fs_mgr/include/fs_mgr.h b/fs_mgr/include/fs_mgr.h
index 80f97fc..e87332f 100644
--- a/fs_mgr/include/fs_mgr.h
+++ b/fs_mgr/include/fs_mgr.h
@@ -50,10 +50,6 @@
     MOUNT_MODE_LATE = 2
 };
 
-// Callback function for verity status
-typedef void fs_mgr_verity_state_callback(fstab_rec* fstab, const char* mount_point, int mode,
-                                          int status);
-
 #define FS_MGR_MNTALL_DEV_IS_METADATA_ENCRYPTED 7
 #define FS_MGR_MNTALL_DEV_NEEDS_METADATA_ENCRYPTION 6
 #define FS_MGR_MNTALL_DEV_FILE_ENCRYPTED 5
@@ -63,7 +59,8 @@
 #define FS_MGR_MNTALL_DEV_NOT_ENCRYPTED 1
 #define FS_MGR_MNTALL_DEV_NOT_ENCRYPTABLE 0
 #define FS_MGR_MNTALL_FAIL (-1)
-int fs_mgr_mount_all(fstab* fstab, int mount_mode);
+// fs_mgr_mount_all() updates fstab entries that reference device-mapper.
+int fs_mgr_mount_all(Fstab* fstab, int mount_mode);
 
 #define FS_MGR_DOMNT_FAILED (-1)
 #define FS_MGR_DOMNT_BUSY (-2)
@@ -72,22 +69,26 @@
 int fs_mgr_do_mount(fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point);
 int fs_mgr_do_mount(fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point,
                     bool need_cp);
+int fs_mgr_do_mount_one(const FstabEntry& entry, const std::string& mount_point = "");
 int fs_mgr_do_mount_one(fstab_rec* rec);
 int fs_mgr_do_tmpfs_mount(const char *n_name);
 fstab_rec const* fs_mgr_get_crypt_entry(fstab const* fstab);
 void fs_mgr_get_crypt_info(fstab* fstab, char* key_loc, char* real_blk_device, size_t size);
 bool fs_mgr_load_verity_state(int* mode);
-bool fs_mgr_update_verity_state(std::function<fs_mgr_verity_state_callback> callback);
+bool fs_mgr_update_verity_state(
+        std::function<void(const std::string& mount_point, int mode)> callback);
 bool fs_mgr_swapon_all(const Fstab& fstab);
+bool fs_mgr_update_logical_partition(FstabEntry* entry);
 bool fs_mgr_update_logical_partition(struct fstab_rec* rec);
 
-int fs_mgr_do_format(fstab_rec* fstab, bool reserve_footer);
+int fs_mgr_do_format(const FstabEntry& entry, bool reserve_footer);
+int fs_mgr_do_format(fstab_rec* rec, bool reserve_footer);
 
 #define FS_MGR_SETUP_VERITY_SKIPPED  (-3)
 #define FS_MGR_SETUP_VERITY_DISABLED (-2)
 #define FS_MGR_SETUP_VERITY_FAIL (-1)
 #define FS_MGR_SETUP_VERITY_SUCCESS 0
-int fs_mgr_setup_verity(fstab_rec* fstab, bool wait_for_verity_dev);
+int fs_mgr_setup_verity(FstabEntry* fstab, bool wait_for_verity_dev);
 
 // Return the name of the super partition if it exists. If a slot number is
 // specified, the super partition for the corresponding metadata slot will be
diff --git a/fs_mgr/include/fs_mgr/roots.h b/fs_mgr/include/fs_mgr/roots.h
new file mode 100644
index 0000000..65c59cf
--- /dev/null
+++ b/fs_mgr/include/fs_mgr/roots.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2018 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 <string>
+
+#include <fs_mgr.h>
+
+namespace android {
+namespace fs_mgr {
+
+// Finds the volume specified by the given path. fs_mgr_get_entry_for_mount_point() does exact match
+// only, so it attempts the prefixes recursively (e.g. "/cache/recovery/last_log",
+// "/cache/recovery", "/cache", "/" for a given path of "/cache/recovery/last_log") and returns the
+// first match or nullptr.
+FstabEntry* GetEntryForPath(Fstab* fstab, const std::string& path);
+
+// Make sure that the volume 'path' is on is mounted.
+// * If 'mount_point' is nullptr, use mount point in fstab. Caller can call
+//   fs_mgr_ensure_path_unmounted() with the same 'path' argument to unmount.
+// * If 'mount_point' is not nullptr, the mount point is overridden. Caller can
+//   call umount(mount_point) to unmount.
+// Returns true on success (volume is mounted).
+bool EnsurePathMounted(Fstab* fstab, const std::string& path, const std::string& mount_point = "");
+
+// Make sure that the volume 'path' is on is unmounted.  Returns true on
+// success (volume is unmounted).
+bool EnsurePathUnmounted(Fstab* fstab, const std::string& path);
+
+// Return "/system" if it is in default fstab, otherwise "/".
+std::string GetSystemRoot();
+
+// Return true iff logical partitions are mapped when partitions are mounted via ensure_path_mounted
+// functions.
+bool LogicalPartitionsMapped();
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/include/fs_mgr_overlayfs.h b/fs_mgr/include/fs_mgr_overlayfs.h
index 0dd9121..4bf2238 100644
--- a/fs_mgr/include/fs_mgr_overlayfs.h
+++ b/fs_mgr/include/fs_mgr_overlayfs.h
@@ -21,10 +21,8 @@
 #include <string>
 #include <vector>
 
-bool fs_mgr_overlayfs_mount_all(fstab* fstab);
-bool fs_mgr_overlayfs_mount_all(const std::vector<fstab_rec*>& fstab);
-std::vector<std::string> fs_mgr_overlayfs_required_devices(fstab* fstab);
-std::vector<std::string> fs_mgr_overlayfs_required_devices(const std::vector<fstab_rec*>& fstab);
+bool fs_mgr_overlayfs_mount_all(Fstab* fstab);
+std::vector<std::string> fs_mgr_overlayfs_required_devices(Fstab* fstab);
 bool fs_mgr_overlayfs_setup(const char* backing = nullptr, const char* mount_point = nullptr,
                             bool* change = nullptr);
 bool fs_mgr_overlayfs_teardown(const char* mount_point = nullptr, bool* change = nullptr);
diff --git a/fs_mgr/include_fstab/fstab/fstab.h b/fs_mgr/include_fstab/fstab/fstab.h
index 4706028..0997254 100644
--- a/fs_mgr/include_fstab/fstab/fstab.h
+++ b/fs_mgr/include_fstab/fstab/fstab.h
@@ -43,7 +43,7 @@
     char* fs_type;
     unsigned long flags;
     char* fs_options;
-    int fs_mgr_flags;
+    uint64_t fs_mgr_flags;
     char* key_loc;
     char* key_dir;
     char* verity_loc;
@@ -118,12 +118,14 @@
     off64_t erase_blk_size = 0;
     off64_t logical_blk_size = 0;
     std::string sysfs_path;
+    std::string vbmeta_partition;
 
     // TODO: Remove this union once fstab_rec is deprecated. It only serves as a
     // convenient way to convert between fstab_rec::fs_mgr_flags and these bools.
     union {
-        int val;
+        uint64_t val;
         struct {
+            // bit 0
             bool wait : 1;
             bool check : 1;
             bool crypt : 1;
@@ -132,6 +134,8 @@
             bool length : 1;
             bool recovery_only : 1;
             bool swap_prio : 1;
+
+            // bit 8
             bool zram_size : 1;
             bool verify : 1;
             bool force_crypt : 1;
@@ -141,6 +145,8 @@
             bool file_encryption : 1;
             bool formattable : 1;
             bool slot_select : 1;
+
+            // bit 16
             bool force_fde_or_fbe : 1;
             bool late_mount : 1;
             bool no_fail : 1;
@@ -149,6 +155,8 @@
             bool reserved_size : 1;
             bool quota : 1;
             bool erase_blk_size : 1;
+
+            // bit 24
             bool logical_blk_size : 1;
             bool avb : 1;
             bool key_directory : 1;
@@ -156,6 +164,10 @@
             bool logical : 1;
             bool checkpoint_blk : 1;
             bool checkpoint_fs : 1;
+            bool first_stage_mount : 1;
+
+            // bit 32
+            bool slot_select_other : 1;
         };
     } fs_mgr_flags;
 
diff --git a/fs_mgr/libfs_avb/fs_avb.cpp b/fs_mgr/libfs_avb/fs_avb.cpp
index c4accad..89c755e 100644
--- a/fs_mgr/libfs_avb/fs_avb.cpp
+++ b/fs_mgr/libfs_avb/fs_avb.cpp
@@ -265,7 +265,7 @@
     return table->AddTarget(std::make_unique<android::dm::DmTargetVerity>(target));
 }
 
-static bool hashtree_dm_verity_setup(struct fstab_rec* fstab_entry,
+static bool hashtree_dm_verity_setup(FstabEntry* fstab_entry,
                                      const AvbHashtreeDescriptor& hashtree_desc,
                                      const std::string& salt, const std::string& root_digest,
                                      bool wait_for_verity_dev) {
@@ -278,7 +278,7 @@
     }
     table.set_readonly(true);
 
-    const std::string mount_point(basename(fstab_entry->mount_point));
+    const std::string mount_point(basename(fstab_entry->mount_point.c_str()));
     android::dm::DeviceMapper& dm = android::dm::DeviceMapper::Instance();
     if (!dm.CreateDevice(mount_point, table)) {
         LERROR << "Couldn't create verity device!";
@@ -295,8 +295,7 @@
     fs_mgr_set_blk_ro(fstab_entry->blk_device);
 
     // Updates fstab_rec->blk_device to verity device name.
-    free(fstab_entry->blk_device);
-    fstab_entry->blk_device = strdup(dev_path.c_str());
+    fstab_entry->blk_device = dev_path;
 
     // Makes sure we've set everything up properly.
     if (wait_for_verity_dev && !fs_mgr_wait_for_file(dev_path, 1s)) {
@@ -449,8 +448,7 @@
     return avb_handle;
 }
 
-AvbHashtreeResult AvbHandle::SetUpAvbHashtree(struct fstab_rec* fstab_entry,
-                                              bool wait_for_verity_dev) {
+AvbHashtreeResult AvbHandle::SetUpAvbHashtree(FstabEntry* fstab_entry, bool wait_for_verity_dev) {
     if (!fstab_entry || status_ == kAvbHandleUninitialized || !avb_slot_data_ ||
         avb_slot_data_->num_vbmeta_images < 1) {
         return AvbHashtreeResult::kFail;
@@ -464,13 +462,13 @@
     // Derives partition_name from blk_device to query the corresponding AVB HASHTREE descriptor
     // to setup dm-verity. The partition_names in AVB descriptors are without A/B suffix.
     std::string partition_name;
-    if (fstab_entry->fs_mgr_flags & MF_LOGICAL) {
+    if (fstab_entry->fs_mgr_flags.logical) {
         partition_name = fstab_entry->logical_partition_name;
     } else {
-        partition_name = basename(fstab_entry->blk_device);
+        partition_name = basename(fstab_entry->blk_device.c_str());
     }
 
-    if (fstab_entry->fs_mgr_flags & MF_SLOTSELECT) {
+    if (fstab_entry->fs_mgr_flags.slot_select) {
         auto ab_suffix = partition_name.rfind(fs_mgr_get_slot_suffix());
         if (ab_suffix != std::string::npos) {
             partition_name.erase(ab_suffix);
diff --git a/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
index 9adab3d..08bdbdc 100644
--- a/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
+++ b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
@@ -85,7 +85,7 @@
     //     failed to get the HASHTREE descriptor, runtime error when set up
     //     device-mapper, etc.
     //   - kDisabled: hashtree is disabled.
-    AvbHashtreeResult SetUpAvbHashtree(fstab_rec* fstab_entry, bool wait_for_verity_dev);
+    AvbHashtreeResult SetUpAvbHashtree(FstabEntry* fstab_entry, bool wait_for_verity_dev);
 
     const std::string& avb_version() const { return avb_version_; }
 
diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index 699b9e7..07f9d66 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -606,14 +606,23 @@
         }
 
         uint64_t sectors = std::min(sectors_needed, region.length());
+        if (sectors < region.length()) {
+            const auto& block_device = block_devices_[region.device_index];
+            if (block_device.alignment) {
+                const uint64_t alignment = block_device.alignment / LP_SECTOR_SIZE;
+                sectors = AlignTo(sectors, alignment);
+                sectors = std::min(sectors, region.length());
+            }
+        }
         CHECK(sectors % sectors_per_block == 0);
 
         auto extent = std::make_unique<LinearExtent>(sectors, region.device_index, region.start);
         new_extents.push_back(std::move(extent));
-        sectors_needed -= sectors;
-        if (!sectors_needed) {
+        if (sectors >= sectors_needed) {
+            sectors_needed = 0;
             break;
         }
+        sectors_needed -= sectors;
     }
     if (sectors_needed) {
         LERROR << "Not enough free space to expand partition: " << partition->name();
diff --git a/fs_mgr/liblp/builder_test.cpp b/fs_mgr/liblp/builder_test.cpp
index 7833a25..3793964 100644
--- a/fs_mgr/liblp/builder_test.cpp
+++ b/fs_mgr/liblp/builder_test.cpp
@@ -209,8 +209,8 @@
         ASSERT_TRUE(builder->ResizePartition(a, a->size() + 4096));
         ASSERT_TRUE(builder->ResizePartition(b, b->size() + 4096));
     }
-    EXPECT_EQ(a->size(), 40960);
-    EXPECT_EQ(b->size(), 40960);
+    EXPECT_EQ(a->size(), 7864320);
+    EXPECT_EQ(b->size(), 7864320);
 
     unique_ptr<LpMetadata> exported = builder->Export();
     ASSERT_NE(exported, nullptr);
@@ -218,7 +218,7 @@
     // Check that each starting sector is aligned.
     for (const auto& extent : exported->extents) {
         ASSERT_EQ(extent.target_type, LP_TARGET_TYPE_LINEAR);
-        EXPECT_EQ(extent.num_sectors, 8);
+        EXPECT_EQ(extent.num_sectors, 1536);
 
         uint64_t lba = extent.target_data * LP_SECTOR_SIZE;
         uint64_t aligned_lba = AlignTo(lba, device_info.alignment, device_info.alignment_offset);
@@ -645,7 +645,7 @@
     EXPECT_EQ(metadata->extents[1].target_type, LP_TARGET_TYPE_LINEAR);
     EXPECT_EQ(metadata->extents[1].target_data, 1472);
     EXPECT_EQ(metadata->extents[1].target_source, 1);
-    EXPECT_EQ(metadata->extents[2].num_sectors, 129088);
+    EXPECT_EQ(metadata->extents[2].num_sectors, 129600);
     EXPECT_EQ(metadata->extents[2].target_type, LP_TARGET_TYPE_LINEAR);
     EXPECT_EQ(metadata->extents[2].target_data, 1472);
     EXPECT_EQ(metadata->extents[2].target_source, 2);
@@ -744,17 +744,41 @@
     EXPECT_EQ(system_a->extents().size(), static_cast<size_t>(1));
     EXPECT_EQ(system_b->extents().size(), static_cast<size_t>(1));
     ASSERT_TRUE(builder->ResizePartition(system_b, 6_GiB));
-    EXPECT_EQ(system_b->extents().size(), static_cast<size_t>(3));
+    EXPECT_EQ(system_b->extents().size(), static_cast<size_t>(2));
 
     unique_ptr<LpMetadata> exported = builder->Export();
     ASSERT_NE(exported, nullptr);
-    ASSERT_EQ(exported->extents.size(), static_cast<size_t>(4));
+    ASSERT_EQ(exported->extents.size(), static_cast<size_t>(3));
     EXPECT_EQ(exported->extents[0].target_data, 10487808);
-    EXPECT_EQ(exported->extents[0].num_sectors, 4194304);
-    EXPECT_EQ(exported->extents[1].target_data, 14682624);
-    EXPECT_EQ(exported->extents[1].num_sectors, 6288896);
-    EXPECT_EQ(exported->extents[2].target_data, 6292992);
-    EXPECT_EQ(exported->extents[2].num_sectors, 2099712);
-    EXPECT_EQ(exported->extents[3].target_data, 1536);
-    EXPECT_EQ(exported->extents[3].num_sectors, 6291456);
+    EXPECT_EQ(exported->extents[0].num_sectors, 10483712);
+    EXPECT_EQ(exported->extents[1].target_data, 6292992);
+    EXPECT_EQ(exported->extents[1].num_sectors, 2099712);
+    EXPECT_EQ(exported->extents[2].target_data, 1536);
+    EXPECT_EQ(exported->extents[2].num_sectors, 6291456);
+}
+
+TEST_F(BuilderTest, PartialExtents) {
+    // super has a minimum extent size of 768KiB.
+    BlockDeviceInfo device_info("super", 1_GiB, 768 * 1024, 0, 4096);
+    auto builder = MetadataBuilder::New(device_info, 65536, 1);
+    ASSERT_NE(builder, nullptr);
+    Partition* system = builder->AddPartition("system", 0);
+    ASSERT_NE(system, nullptr);
+    Partition* vendor = builder->AddPartition("vendor", 0);
+    ASSERT_NE(vendor, nullptr);
+    ASSERT_TRUE(builder->ResizePartition(system, device_info.alignment + 4096));
+    ASSERT_TRUE(builder->ResizePartition(vendor, device_info.alignment));
+    ASSERT_EQ(system->size(), device_info.alignment * 2);
+    ASSERT_EQ(vendor->size(), device_info.alignment);
+
+    ASSERT_TRUE(builder->ResizePartition(system, device_info.alignment * 2));
+    ASSERT_EQ(system->extents().size(), static_cast<size_t>(1));
+
+    unique_ptr<LpMetadata> exported = builder->Export();
+    ASSERT_NE(exported, nullptr);
+    ASSERT_EQ(exported->extents.size(), static_cast<size_t>(2));
+    EXPECT_EQ(exported->extents[0].target_data, 1536);
+    EXPECT_EQ(exported->extents[0].num_sectors, 3072);
+    EXPECT_EQ(exported->extents[1].target_data, 4608);
+    EXPECT_EQ(exported->extents[1].num_sectors, 1536);
 }
diff --git a/fs_mgr/liblp/writer.cpp b/fs_mgr/liblp/writer.cpp
index d8195ca..454258b 100644
--- a/fs_mgr/liblp/writer.cpp
+++ b/fs_mgr/liblp/writer.cpp
@@ -84,7 +84,6 @@
 // with potentially invalid metadata, or random partition data with metadata.
 static bool ValidateAndSerializeMetadata(const IPartitionOpener& opener, const LpMetadata& metadata,
                                          const std::string& slot_suffix, std::string* blob) {
-    const LpMetadataHeader& header = metadata.header;
     const LpMetadataGeometry& geometry = metadata.geometry;
 
     *blob = SerializeMetadata(metadata);
diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index 561debb..9e211e3 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -36,17 +36,28 @@
 
 Returns: true if device is in fastboot mode" ]
 inFastboot() {
-  fastboot devices | grep "^${ANDROID_SERIAL}[${SPACE}${TAB}]" > /dev/null
+  fastboot devices |
+    if [ -n "${ANDROID_SERIAL}" ]; then
+      grep "^${ANDROID_SERIAL}[${SPACE}${TAB}]" > /dev/null
+    else
+      wc -l | grep '^1$' >/dev/null
+    fi
 }
 
 [ "USAGE: inAdb
 
 Returns: true if device is in adb mode" ]
 inAdb() {
-  adb devices | grep -v 'List of devices attached' | grep "^${ANDROID_SERIAL}[${SPACE}${TAB}]" > /dev/null
+  adb devices |
+    grep -v 'List of devices attached' |
+    if [ -n "${ANDROID_SERIAL}" ]; then
+      grep "^${ANDROID_SERIAL}[${SPACE}${TAB}]" > /dev/null
+    else
+      wc -l | grep '^1$' >/dev/null
+    fi
 }
 
-[ "USAGE: adb_sh <commands>
+[ "USAGE: adb_sh <commands> </dev/stdin >/dev/stdout 2>/dev/stderr
 
 Returns: true if the command succeeded" ]
 adb_sh() {
@@ -81,12 +92,12 @@
 
 Returns: true if device is (likely) a debug build" ]
 isDebuggable() {
-  if inAdb && [ 1 -ne `get_property ro.debuggable` ]; then
+  if inAdb && [ 1 -ne "`get_property ro.debuggable`" ]; then
     false
   fi
 }
 
-[ "USAGE: adb_su <commands>
+[ "USAGE: adb_su <commands> </dev/stdin >/dev/stdout 2>/dev/stderr
 
 Returns: true if the command running as root succeeded" ]
 adb_su() {
@@ -277,30 +288,59 @@
   echo "${ORANGE}[  WARNING ]${NORMAL} device not in adb mode ... waiting 2 minutes"
   adb_wait 2m
 fi
-inAdb || die "device not in adb mode"
+inAdb || die "specified device not in adb mode"
 isDebuggable || die "device not a debug build"
+enforcing=true
+if ! adb_su getenforce </dev/null | grep 'Enforcing' >/dev/null; then
+  echo "${ORANGE}[  WARNING ]${NORMAL} device does not have sepolicy in enforcing mode"
+  enforcing=false
+fi
 
 # Do something
 
 echo "${GREEN}[ RUN      ]${NORMAL} Testing kernel support for overlayfs" >&2
 
+overlayfs_supported=true;
 adb_wait || die "wait for device failed"
 adb_sh ls -d /sys/module/overlay </dev/null >/dev/null &&
   echo "${GREEN}[       OK ]${NORMAL} overlay module present" >&2 ||
-  die "overlay module not present"
-adb_su ls /sys/module/overlay/parameters/override_creds </dev/null >/dev/null &&
-  echo "${GREEN}[       OK ]${NORMAL} overlay module supports override_creds" >&2 ||
-  die "overlay module can not be used on ANDROID"
+  (
+    echo "${ORANGE}[  WARNING ]${NORMAL} overlay module not present" >&2 &&
+      false
+  ) ||
+  overlayfs_supported=false
+if ${overlayfs_supported}; then
+  case `adb_sh uname -r </dev/null` in
+    4.[6789].* | 4.[1-9][0-9]* | [56789].*)
+      adb_su ls /sys/module/overlay/parameters/override_creds </dev/null >/dev/null &&
+        echo "${GREEN}[       OK ]${NORMAL} overlay module supports override_creds" >&2 ||
+        (
+          echo "${ORANGE}[  WARNING ]${NORMAL} overlay module does not support override_creds" >&2 &&
+          false
+        ) ||
+        overlayfs_supported=false;
+      ;;
+    *)
+      echo "${GREEN}[       OK ]${NORMAL} overlay module uses callers creds" >&2
+      ;;
+  esac
+fi
+
 adb_root ||
   die "initial setup"
 
 echo "${GREEN}[ RUN      ]${NORMAL} Checking current overlayfs status" >&2
 
+# We can not universally use adb enable-verity to ensure device is
+# in a overlayfs disabled state since it can prevent reboot on
+# devices that remount the physical content rather than overlayfs.
+# So lets do our best to surgically wipe the overlayfs state without
+# having to go through enable-verity transition.
 reboot=false
 OVERLAYFS_BACKING="cache mnt/scratch"
 for d in ${OVERLAYFS_BACKING}; do
   if adb_sh ls -d /${d}/overlay </dev/null >/dev/null 2>/dev/null; then
-    echo "${ORANGE}[  WARNING ]${NORMAL} /${d}/overlay is setup, wiping" >&2
+    echo "${ORANGE}[  WARNING ]${NORMAL} /${d}/overlay is setup, surgically wiping" >&2
     adb_sh rm -rf /${d}/overlay </dev/null ||
       die "/${d}/overlay wipe"
     reboot=true
@@ -309,9 +349,10 @@
 if ${reboot}; then
   echo "${ORANGE}[  WARNING ]${NORMAL} rebooting before test" >&2
   adb_reboot &&
-    adb_wait 2m &&
-    adb_root ||
-    die "reboot after wipe"
+    adb_wait 2m ||
+    die "lost device after reboot after wipe"
+  adb_root ||
+    die "lost device after elevation to root after wipe"
 fi
 D=`adb_sh df -k </dev/null` &&
   H=`echo "${D}" | head -1` &&
@@ -320,105 +361,160 @@
   echo "${D}" &&
   echo "${ORANGE}[  WARNING ]${NORMAL} overlays present before setup" >&2 ||
   echo "${GREEN}[       OK ]${NORMAL} no overlay present before setup" >&2
-adb_sh df -k `adb_sh cat /proc/mounts |
-                skip_administrative_mounts data |
-                cut -s -d' ' -f1`
+overlayfs_needed=true
+D=`adb_sh cat /proc/mounts </dev/null |
+   skip_administrative_mounts data |
+   cut -s -d' ' -f1`
+D=`adb_sh df -k ${D} </dev/null`
+echo "${D}"
+if [ X"${D}" = X"${D##* 100[%] }" ]; then
+  overlayfs_needed=false
+elif ! ${overlayfs_supported}; then
+  die "need overlayfs, but do not have it"
+fi
 
 echo "${GREEN}[ RUN      ]${NORMAL} disable verity" >&2
 
 T=`adb_date`
-D=`adb disable-verity 2>&1`
+H=`adb disable-verity 2>&1`
 err=${?}
-if [ ${err} != 0 -o X"${D}" != X"${D##*setup failed}" ]; then
-  echo "${D%?Now reboot your device for settings to take effect}"
-  die -t ${T} "setup for overlay"
-fi
+L=
+D="${H%?Now reboot your device for settings to take effect}"
 if [ X"${D}" != X"${D##*using overlayfs}" ]; then
   echo "${GREEN}[       OK ]${NORMAL} using overlayfs" >&2
 fi
-reboot=false
-if [ X"${D}" != X"${D##*Successfully disabled verity}" ]; then
-  echo "${GREEN}[       OK ]${NORMAL} disabled verity" >&2
-  reboot=true
-else
-  echo "${ORANGE}[  WARNING ]${NORMAL} verity already disabled" >&2
+if [ ${err} != 0 ]; then
+  echo "${H}"
+  ( [ -n "${L}" ] && echo "${L}" && false ) ||
+  die -t "${T}" "disable-verity"
 fi
-D=`adb_sh df -k </dev/null` &&
-  H=`echo "${D}" | head -1` &&
-  D=`echo "${D}" | grep "^overlay " | true` &&
-  [ -n "${D}" ] &&
-  ( echo "${H}" && echo "${D}" && true ) &&
-  die -t ${T} "overlay takeover unexpected"
-L=
-if ${reboot}; then
+rebooted=false
+if [ X"${D}" != X"${H}" ]; then
+  echo "${H}"
+  if [ X"${D}" != X"${D##*setup failed}" ]; then
+    echo "${ORANGE}[  WARNING ]${NORMAL} overlayfs setup whined" >&2
+  fi
+  D=`adb_sh df -k </dev/null` &&
+    H=`echo "${D}" | head -1` &&
+    D=`echo "${D}" | grep "^overlay " || true` &&
+    [ -z "${D}" ] ||
+    ( echo "${H}" && echo "${D}" && false ) ||
+    die -t ${T} "overlay takeover unexpected at this phase"
+  echo "${GREEN}[     INFO ]${NORMAL} rebooting as requested" >&2
   L=`adb_logcat -b all -v nsec -t ${T} 2>&1`
   adb_reboot &&
     adb_wait 2m ||
-    die "reboot after verity disabled failed"
-  T=
+    die "lost device after reboot requested"
+  adb_root ||
+    die "lost device after elevation to root"
+  rebooted=true
+  # re-disable verity to see the setup remarks expected
+  T=`adb_date`
+  H=`adb disable-verity 2>&1`
+  err=${?}
+  D="${H%?Now reboot your device for settings to take effect}"
+  if [ X"${D}" != X"${D##*using overlayfs}" ]; then
+    echo "${GREEN}[       OK ]${NORMAL} using overlayfs" >&2
+  fi
+  if [ ${err} != 0 ]; then
+    T=
+  fi
+fi
+if ${overlayfs_supported} && ${overlayfs_needed} && [ X"${D}" != X"${D##*setup failed}" ]; then
+  echo "${D}"
+  ( [ -n "${L}" ] && echo "${L}" && false ) ||
+  die -t "${T}" "setup for overlay"
+fi
+if [ X"${D}" != X"${D##*Successfully disabled verity}" ]; then
+  echo "${H}"
+  D=`adb_sh df -k </dev/null` &&
+    H=`echo "${D}" | head -1` &&
+    D=`echo "${D}" | grep "^overlay " || true` &&
+    [ -z "${D}" ] ||
+    ( echo "${H}" && echo "${D}" && false ) ||
+    ( [ -n "${L}" ] && echo "${L}" && false ) ||
+    die -t "${T}" "overlay takeover unexpected"
+  [ -n "${L}" ] && echo "${L}"
+  die -t "${T}" "unexpected report of verity being disabled a second time"
+elif ${rebooted}; then
+  echo "${GREEN}[       OK ]${NORMAL} verity already disabled" >&2
+else
+  echo "${ORANGE}[  WARNING ]${NORMAL} verity already disabled" >&2
 fi
 
 echo "${GREEN}[ RUN      ]${NORMAL} remount" >&2
 
-adb_root &&
-  adb remount ||
+adb remount ||
   ( [ -n "${L}" ] && echo "${L}" && false ) ||
   die -t "${T}" "adb remount failed"
 D=`adb_sh df -k </dev/null` &&
   H=`echo "${D}" | head -1` &&
   D=`echo "${D}" | grep "^overlay "` ||
-  ( [ -n "${L}" ] && echo "${L}" && false ) ||
-  die -t ${T} "overlay takeover failed"
-echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
-  echo "${ORANGE}[  WARNING ]${NORMAL} overlay takeover not complete" >&2
-scratch_partition=scratch
-if echo "${D}" | grep " /mnt/scratch" >/dev/null; then
-  echo "${BLUE}[     INFO ]${NORMAL} using ${scratch_partition} dynamic partition for overrides" >&2
-fi
-M=`adb_sh cat /proc/mounts | sed -n 's@\([^ ]*\) /mnt/scratch \([^ ]*\) .*@\2 on \1@p'`
-[ -n "${M}" ] &&
-  echo "${BLUE}[     INFO ]${NORMAL} scratch filesystem ${M}"
-uses_dynamic_scratch=true
-if [ "${M}" != "${M##*/dev/block/by-name/}" ]; then
-  uses_dynamic_scratch=false
-  scratch_partition="${M##*/dev/block/by-name/}"
-fi
-scratch_size=`adb_sh df -k /mnt/scratch </dev/null 2>/dev/null |
-              while read device kblocks used available use mounted on; do
-                if [ "/mnt/scratch" = "\${mounted}" ]; then
-                  echo \${kblocks}
-                fi
-              done` &&
-  [ -n "${scratch_size}" ] ||
-  die "scratch size"
-echo "${BLUE}[     INFO ]${NORMAL} scratch size ${scratch_size}KB" >&2
-for d in ${OVERLAYFS_BACKING}; do
-  if adb_sh ls -d /${d}/overlay/system/upper </dev/null >/dev/null 2>/dev/null; then
-    echo "${BLUE}[     INFO ]${NORMAL} /${d}/overlay is setup" >&2
+  ( [ -n "${L}" ] && echo "${L}" && false )
+ret=${?}
+uses_dynamic_scratch=false
+scratch_partition=
+if ${overlayfs_needed}; then
+  if [ ${ret} != 0 ]; then
+    die -t ${T} "overlay takeover failed"
   fi
-done
-
-echo "${H}" &&
-  echo "${D}" &&
   echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
-  die  "overlay takeover after remount"
-!(adb_sh grep "^overlay " /proc/mounts </dev/null | grep " overlay ro,") &&
-  !(adb_sh grep " rw," /proc/mounts </dev/null | skip_administrative_mounts data) ||
-  die "remount overlayfs missed a spot (ro)"
+   echo "${ORANGE}[  WARNING ]${NORMAL} overlay takeover not complete" >&2
+  scratch_partition=scratch
+  if echo "${D}" | grep " /mnt/scratch" >/dev/null; then
+    echo "${BLUE}[     INFO ]${NORMAL} using ${scratch_partition} dynamic partition for overrides" >&2
+  fi
+  M=`adb_sh cat /proc/mounts </dev/null |
+     sed -n 's@\([^ ]*\) /mnt/scratch \([^ ]*\) .*@\2 on \1@p'`
+  [ -n "${M}" ] &&
+    echo "${BLUE}[     INFO ]${NORMAL} scratch filesystem ${M}"
+  uses_dynamic_scratch=true
+  if [ "${M}" != "${M##*/dev/block/by-name/}" ]; then
+    uses_dynamic_scratch=false
+    scratch_partition="${M##*/dev/block/by-name/}"
+  fi
+  scratch_size=`adb_sh df -k /mnt/scratch </dev/null 2>/dev/null |
+                while read device kblocks used available use mounted on; do
+                  if [ "/mnt/scratch" = "\${mounted}" ]; then
+                    echo \${kblocks}
+                  fi
+                done` &&
+    [ -n "${scratch_size}" ] ||
+    die "scratch size"
+  echo "${BLUE}[     INFO ]${NORMAL} scratch size ${scratch_size}KB" >&2
+  for d in ${OVERLAYFS_BACKING}; do
+    if adb_sh ls -d /${d}/overlay/system/upper </dev/null >/dev/null 2>/dev/null; then
+      echo "${BLUE}[     INFO ]${NORMAL} /${d}/overlay is setup" >&2
+    fi
+  done
+
+  echo "${H}" &&
+    echo "${D}" &&
+    echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
+    die  "overlay takeover after remount"
+  !(adb_sh grep "^overlay " /proc/mounts </dev/null | grep " overlay ro,") &&
+    !(adb_sh grep " rw," /proc/mounts </dev/null |
+      skip_administrative_mounts data) ||
+    die "remount overlayfs missed a spot (ro)"
+else
+  if [ ${ret} = 0 ]; then
+    die -t ${T} "unexpected overlay takeover"
+  fi
+fi
 
 # Check something
 
-echo "${GREEN}[ RUN      ]${NORMAL} push content to system and vendor" >&2
+echo "${GREEN}[ RUN      ]${NORMAL} push content to /system and /vendor" >&2
 
 A="Hello World! $(date)"
 echo "${A}" | adb_sh "cat - > /system/hello"
 echo "${A}" | adb_sh "cat - > /vendor/hello"
 B="`adb_cat /system/hello`" ||
   die "sytem hello"
-check_eq "${A}" "${B}" system before reboot
+check_eq "${A}" "${B}" /system before reboot
 B="`adb_cat /vendor/hello`" ||
   die "vendor hello"
-check_eq "${A}" "${B}" vendor before reboot
+check_eq "${A}" "${B}" /vendor before reboot
 
 echo "${GREEN}[ RUN      ]${NORMAL} reboot to confirm content persistent" >&2
 
@@ -426,89 +522,108 @@
   adb_wait 2m ||
   die "reboot after override content added failed"
 
-D=`adb_su df -k </dev/null` &&
-  H=`echo "${D}" | head -1` &&
-  D=`echo "${D}" | grep "^overlay "` ||
-  ( echo "${L}" && false ) ||
-  die -d "overlay takeover failed after reboot"
+if ${overlayfs_needed}; then
+  D=`adb_su df -k </dev/null` &&
+    H=`echo "${D}" | head -1` &&
+    D=`echo "${D}" | grep "^overlay "` ||
+    ( echo "${L}" && false ) ||
+    die -d "overlay takeover failed after reboot"
 
-adb_su "sed -n '1,/overlay \\/system/p' /proc/mounts" </dev/null |
-  skip_administrative_mounts |
-  grep -v ' \(squashfs\|ext4\|f2fs\) ' &&
-  echo "${ORANGE}[  WARNING ]${NORMAL} overlay takeover after first stage init" >&2 ||
-  echo "${GREEN}[       OK ]${NORMAL} overlay takeover in first stage init" >&2
+  adb_su "sed -n '1,/overlay \\/system/p' /proc/mounts" </dev/null |
+    skip_administrative_mounts |
+    grep -v ' \(squashfs\|ext4\|f2fs\) ' &&
+    echo "${ORANGE}[  WARNING ]${NORMAL} overlay takeover after first stage init" >&2 ||
+    echo "${GREEN}[       OK ]${NORMAL} overlay takeover in first stage init" >&2
+fi
 
 B="`adb_cat /system/hello`" ||
-  die "re-read system hello after reboot"
-check_eq "${A}" "${B}" system after reboot
+  die "re-read /system/hello after reboot"
+check_eq "${A}" "${B}" /system after reboot
+echo "${GREEN}[       OK ]${NORMAL} /system content remains after reboot" >&2
 # Only root can read vendor if sepolicy permissions are as expected
-B="`adb_cat /vendor/hello`" &&
-  die "re-read vendor hello after reboot w/o root"
-check_eq "cat: /vendor/hello: Permission denied" "${B}" vendor after reboot w/o root
+if ${enforcing}; then
+  B="`adb_cat /vendor/hello`" &&
+    die "re-read /vendor/hello after reboot w/o root"
+  check_eq "cat: /vendor/hello: Permission denied" "${B}" vendor after reboot w/o root
+  echo "${GREEN}[       OK ]${NORMAL} /vendor content correct MAC after reboot" >&2
+fi
 adb_root &&
   B="`adb_cat /vendor/hello`" ||
-  die "re-read vendor hello after reboot"
+  die "re-read /vendor/hello after reboot"
 check_eq "${A}" "${B}" vendor after reboot
+echo "${GREEN}[       OK ]${NORMAL} /vendor content remains after reboot" >&2
 
 echo "${GREEN}[ RUN      ]${NORMAL} flash vendor, confirm its content disappears" >&2
 
-[ -n "${ANDROID_PRODUCT_OUT}" ] &&
-  adb reboot-fastboot &&
-  fastboot_wait 2m &&
-  fastboot flash vendor ||
-  ( fastboot reboot && false) ||
-  die "fastboot flash vendor"
-fastboot_getvar partition-type:${scratch_partition} raw ||
-  ( fastboot reboot && false) ||
-  die "fastboot can not see ${scratch_partition} parameters"
-if ${uses_dynamic_scratch}; then
-  # check ${scratch_partition} via fastboot
-  fastboot_getvar has-slot:${scratch_partition} no &&
-    fastboot_getvar is-logical:${scratch_partition} yes ||
-    ( fastboot reboot && false) ||
-    die "fastboot can not see ${scratch_partition} parameters"
+H=`adb_sh echo '${HOSTNAME}' </dev/null 2>/dev/null`
+if [ -z "${ANDROID_PRODUCT_OUT}" ]; then
+  echo "${ORANGE}[  WARNING ]${NORMAL} build tree not setup, skipping"
+elif [ ! -s "${ANDROID_PRODUCT_OUT}/vendor.img" ]; then
+  echo "${ORANGE}[  WARNING ]${NORMAL} vendor image missing, skipping"
+elif [ "${ANDROID_PRODUCT_OUT}" = "${ANDROID_PRODUCT_OUT%*/${H}}" ]; then
+  echo "${ORANGE}[  WARNING ]${NORMAL} wrong vendor image, skipping"
 else
-  fastboot_getvar is-logical:${scratch_partition} no ||
+  adb reboot-fastboot &&
+    fastboot_wait 2m &&
+    fastboot flash vendor ||
     ( fastboot reboot && false) ||
-    die "fastboot can not see ${scratch_partition} parameters"
+    die "fastboot flash vendor"
+  if [ -n "${scratch_paritition}" ]; then
+    fastboot_getvar partition-type:${scratch_partition} raw ||
+      ( fastboot reboot && false) ||
+      die "fastboot can not see ${scratch_partition} parameters"
+    if ${uses_dynamic_scratch}; then
+      # check ${scratch_partition} via fastboot
+      fastboot_getvar has-slot:${scratch_partition} no &&
+        fastboot_getvar is-logical:${scratch_partition} yes ||
+        ( fastboot reboot && false) ||
+        die "fastboot can not see ${scratch_partition} parameters"
+    else
+      fastboot_getvar is-logical:${scratch_partition} no ||
+        ( fastboot reboot && false) ||
+        die "fastboot can not see ${scratch_partition} parameters"
+    fi
+    if ! ${uses_dynamic_scratch}; then
+      fastboot reboot-bootloader ||
+        die "Reboot into fastboot"
+    fi
+    if ${uses_dynamic_scratch}; then
+      echo "${BLUE}[     INFO ]${NORMAL} expect fastboot erase ${scratch_partition} to fail" >&2
+      fastboot erase ${scratch_partition} &&
+        ( fastboot reboot || true) &&
+        die "fastboot can erase ${scratch_partition}"
+    fi
+    echo "${BLUE}[     INFO ]${NORMAL} expect fastboot format ${scratch_partition} to fail" >&2
+    fastboot format ${scratch_partition} &&
+      ( fastboot reboot || true) &&
+      die "fastboot can format ${scratch_partition}"
+  fi
+  fastboot reboot ||
+    die "can not reboot out of fastboot"
+  echo "${ORANGE}[  WARNING ]${NORMAL} adb after fastboot ... waiting 2 minutes"
+  adb_wait 2m ||
+    die "did not reboot after flash"
+  if ${overlayfs_needed}; then
+    adb_root &&
+      D=`adb_sh df -k </dev/null` &&
+      H=`echo "${D}" | head -1` &&
+      D=`echo "${D}" | grep "^overlay "` &&
+      echo "${H}" &&
+      echo "${D}" &&
+      echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
+      die  "overlay /system takeover after flash vendor"
+    echo "${D}" | grep "^overlay .* /vendor\$" >/dev/null &&
+      die  "overlay supposed to be minus /vendor takeover after flash vendor"
+  fi
+  B="`adb_cat /system/hello`" ||
+    die "re-read /system/hello after flash vendor"
+  check_eq "${A}" "${B}" system after flash vendor
+  adb_root ||
+    die "adb root"
+  B="`adb_cat /vendor/hello`" &&
+    die "re-read /vendor/hello after flash vendor"
+  check_eq "cat: /vendor/hello: No such file or directory" "${B}" vendor after flash vendor
 fi
-if ! ${uses_dynamic_scratch}; then
-  fastboot reboot-bootloader ||
-    die "Reboot into fastboot"
-fi
-if ${uses_dynamic_scratch}; then
-  echo "${BLUE}[     INFO ]${NORMAL} expect fastboot erase ${scratch_partition} to fail" >&2
-  fastboot erase ${scratch_partition} &&
-    ( fastboot reboot || true) &&
-    die "fastboot can erase ${scratch_partition}"
-fi
-echo "${BLUE}[     INFO ]${NORMAL} expect fastboot format ${scratch_partition} to fail" >&2
-fastboot format ${scratch_partition} &&
-  ( fastboot reboot || true) &&
-  die "fastboot can format ${scratch_partition}"
-fastboot reboot ||
-  die "can not reboot out of fastboot"
-echo "${ORANGE}[  WARNING ]${NORMAL} adb after fastboot ... waiting 2 minutes"
-adb_wait 2m ||
-  die "did not reboot after flash"
-adb_root &&
-  D=`adb_sh df -k </dev/null` &&
-  H=`echo "${D}" | head -1` &&
-  D=`echo "${D}" | grep "^overlay "` &&
-  echo "${H}" &&
-  echo "${D}" &&
-  echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
-  die  "overlay system takeover after flash vendor"
-echo "${D}" | grep "^overlay .* /vendor\$" >/dev/null &&
-  die  "overlay minus vendor takeover after flash vendor"
-B="`adb_cat /system/hello`" ||
-  die "re-read system hello after flash vendor"
-check_eq "${A}" "${B}" system after flash vendor
-adb_root ||
-  die "adb root"
-B="`adb_cat /vendor/hello`" &&
-  die "re-read vendor hello after flash vendor"
-check_eq "cat: /vendor/hello: No such file or directory" "${B}" vendor after flash vendor
 
 echo "${GREEN}[ RUN      ]${NORMAL} remove test content (cleanup)" >&2
 
@@ -518,38 +633,41 @@
   adb_sh rm /system/hello </dev/null ||
   die -t ${T} "cleanup hello"
 B="`adb_cat /system/hello`" &&
-  die "re-read system hello after rm"
+  die "re-read /system/hello after rm"
 check_eq "cat: /system/hello: No such file or directory" "${B}" after flash rm
 B="`adb_cat /vendor/hello`" &&
-  die "re-read vendor hello after rm"
+  die "re-read /vendor/hello after rm"
 check_eq "cat: /vendor/hello: No such file or directory" "${B}" after flash rm
 
-echo "${GREEN}[ RUN      ]${NORMAL} test fastboot flash to ${scratch_partition}" >&2
+if [ -n "${scratch_partition}" ]; then
 
-adb reboot-fastboot ||
-  die "Reboot into fastbootd"
-dd if=/dev/zero of=/tmp/adb-remount-test.img bs=4096 count=16 2>/dev/null &&
-  fastboot_wait 2m ||
-  ( rm /tmp/adb-remount-test.img && false) ||
-  die "reboot into fastboot"
-fastboot flash --force ${scratch_partition} /tmp/adb-remount-test.img
-err=${?}
-rm /tmp/adb-remount-test.img
-fastboot reboot ||
-  die "can not reboot out of fastboot"
-[ 0 -eq ${err} ] ||
-  die "fastboot flash ${scratch_partition}"
-adb_wait 2m &&
-  adb_root ||
-  die "did not reboot after flash"
-T=`adb_date`
-D=`adb disable-verity 2>&1`
-err=${?}
-echo "${D}"
-[ ${err} = 0 ] &&
-  [ X"${D}" = X"${D##*setup failed}" ] &&
-  [ X"${D}" != X"${D##*using overlayfs}" ] &&
-  echo "${GREEN}[       OK ]${NORMAL} ${scratch_partition} recreated" >&2 ||
-  die -t ${T} "setup for overlayfs"
+  echo "${GREEN}[ RUN      ]${NORMAL} test fastboot flash to ${scratch_partition}" >&2
+
+  adb reboot-fastboot ||
+    die "Reboot into fastbootd"
+  dd if=/dev/zero of=/tmp/adb-remount-test.img bs=4096 count=16 2>/dev/null &&
+    fastboot_wait 2m ||
+    ( rm /tmp/adb-remount-test.img && false) ||
+    die "reboot into fastboot"
+  fastboot flash --force ${scratch_partition} /tmp/adb-remount-test.img
+  err=${?}
+  rm /tmp/adb-remount-test.img
+  fastboot reboot ||
+    die "can not reboot out of fastboot"
+  [ 0 -eq ${err} ] ||
+    die "fastboot flash ${scratch_partition}"
+  adb_wait 2m &&
+    adb_root ||
+    die "did not reboot after flash"
+  T=`adb_date`
+  D=`adb disable-verity 2>&1`
+  err=${?}
+  echo "${D}"
+  [ ${err} = 0 ] &&
+    [ X"${D}" = X"${D##*setup failed}" ] &&
+    [ X"${D}" != X"${D##*using overlayfs}" ] &&
+    echo "${GREEN}[       OK ]${NORMAL} ${scratch_partition} recreated" >&2 ||
+    die -t ${T} "setup for overlayfs"
+fi
 
 echo "${GREEN}[  PASSED  ]${NORMAL} adb remount" >&2
diff --git a/init/builtins.cpp b/init/builtins.cpp
index b382126..7fd4e27 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -473,9 +473,10 @@
         // Only needed if someone explicitly changes the default log level in their init.rc.
         android::base::ScopedLogSeverity info(android::base::INFO);
 
-        struct fstab* fstab = fs_mgr_read_fstab(fstabfile);
-        int child_ret = fs_mgr_mount_all(fstab, mount_mode);
-        fs_mgr_free_fstab(fstab);
+        Fstab fstab;
+        ReadFstabFromFile(fstabfile, &fstab);
+
+        int child_ret = fs_mgr_mount_all(&fstab, mount_mode);
         if (child_ret == -1) {
             PLOG(ERROR) << "fs_mgr_mount_all returned an error";
         }
@@ -734,13 +735,10 @@
     return Success();
 }
 
-static void verity_update_property(fstab_rec *fstab, const char *mount_point,
-                                   int mode, int status) {
-    property_set("partition."s + mount_point + ".verified", std::to_string(mode));
-}
-
 static Result<Success> do_verity_update_state(const BuiltinArguments& args) {
-    if (!fs_mgr_update_verity_state(verity_update_property)) {
+    if (!fs_mgr_update_verity_state([](const std::string& mount_point, int mode) {
+            property_set("partition." + mount_point + ".verified", std::to_string(mode));
+        })) {
         return Error() << "fs_mgr_update_verity_state() failed";
     }
     return Success();
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index 6ae1123..acefdf0 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -42,6 +42,8 @@
 #include "uevent_listener.h"
 #include "util.h"
 
+using android::base::ReadFileToString;
+using android::base::Split;
 using android::base::Timer;
 using android::fs_mgr::AvbHandle;
 using android::fs_mgr::AvbHashtreeResult;
@@ -56,7 +58,7 @@
 // ------------------
 class FirstStageMount {
   public:
-    FirstStageMount();
+    FirstStageMount(Fstab fstab);
     virtual ~FirstStageMount() = default;
 
     // The factory method to create either FirstStageMountVBootV1 or FirstStageMountVBootV2
@@ -70,8 +72,10 @@
     bool InitRequiredDevices();
     bool InitMappedDevice(const std::string& verity_device);
     bool CreateLogicalPartitions();
-    bool MountPartition(fstab_rec* fstab_rec);
+    bool MountPartition(FstabEntry* fstab_entry);
     bool MountPartitions();
+    bool TrySwitchSystemAsRoot();
+    bool TrySkipMountingPartitions();
     bool IsDmLinearEnabled();
     bool GetDmLinearMetadataDevice();
     bool InitDmLinearBackingDevices(const android::fs_mgr::LpMetadata& metadata);
@@ -80,13 +84,12 @@
 
     // Pure virtual functions.
     virtual bool GetDmVerityDevices() = 0;
-    virtual bool SetUpDmVerity(fstab_rec* fstab_rec) = 0;
+    virtual bool SetUpDmVerity(FstabEntry* fstab_entry) = 0;
 
     bool need_dm_verity_;
 
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab_;
+    Fstab fstab_;
     std::string lp_metadata_partition_;
-    std::vector<fstab_rec*> mount_fstab_recs_;
     std::set<std::string> required_devices_partition_names_;
     std::string super_partition_name_;
     std::unique_ptr<DeviceHandler> device_handler_;
@@ -95,33 +98,37 @@
 
 class FirstStageMountVBootV1 : public FirstStageMount {
   public:
-    FirstStageMountVBootV1() = default;
+    FirstStageMountVBootV1(Fstab fstab) : FirstStageMount(std::move(fstab)) {}
     ~FirstStageMountVBootV1() override = default;
 
   protected:
     bool GetDmVerityDevices() override;
-    bool SetUpDmVerity(fstab_rec* fstab_rec) override;
+    bool SetUpDmVerity(FstabEntry* fstab_entry) override;
 };
 
 class FirstStageMountVBootV2 : public FirstStageMount {
   public:
     friend void SetInitAvbVersionInRecovery();
 
-    FirstStageMountVBootV2();
+    FirstStageMountVBootV2(Fstab fstab);
     ~FirstStageMountVBootV2() override = default;
 
   protected:
     bool GetDmVerityDevices() override;
-    bool SetUpDmVerity(fstab_rec* fstab_rec) override;
+    bool SetUpDmVerity(FstabEntry* fstab_entry) override;
     bool InitAvbHandle();
 
-    std::string device_tree_vbmeta_parts_;
+    std::vector<std::string> vbmeta_partitions_;
     AvbUniquePtr avb_handle_;
 };
 
 // Static Functions
 // ----------------
-static inline bool IsDtVbmetaCompatible() {
+static inline bool IsDtVbmetaCompatible(const Fstab& fstab) {
+    if (std::any_of(fstab.begin(), fstab.end(),
+                    [](const auto& entry) { return entry.fs_mgr_flags.avb; })) {
+        return true;
+    }
     return is_android_dt_value_expected("vbmeta/compatible", "android,vbmeta");
 }
 
@@ -129,34 +136,26 @@
     return access("/system/bin/recovery", F_OK) == 0;
 }
 
-// Class Definitions
-// -----------------
-FirstStageMount::FirstStageMount()
-    : need_dm_verity_(false),
-      fstab_(fs_mgr_read_fstab_dt(), fs_mgr_free_fstab),
-      uevent_listener_(16 * 1024 * 1024) {
-    // Stores fstab_->recs[] into mount_fstab_recs_ (vector<fstab_rec*>)
-    // for easier manipulation later, e.g., range-base for loop.
-    if (fstab_) {
-        // DT Fstab predated having a first_stage_mount fs_mgr flag, so if it exists, we use it.
-        for (int i = 0; i < fstab_->num_entries; i++) {
-            mount_fstab_recs_.push_back(&fstab_->recs[i]);
-        }
-    } else {
-        // Fstab found in first stage ramdisk, which should be a copy of the normal fstab.
-        // Mounts intended for first stage are explicitly flagged as such.
-        fstab_.reset(fs_mgr_read_fstab_default());
-        if (fstab_) {
-            for (int i = 0; i < fstab_->num_entries; i++) {
-                if (fs_mgr_is_first_stage_mount(&fstab_->recs[i])) {
-                    mount_fstab_recs_.push_back(&fstab_->recs[i]);
-                }
-            }
+static Fstab ReadFirstStageFstab() {
+    Fstab fstab;
+    if (!ReadFstabFromDt(&fstab)) {
+        if (ReadDefaultFstab(&fstab)) {
+            fstab.erase(std::remove_if(fstab.begin(), fstab.end(),
+                                       [](const auto& entry) {
+                                           return !entry.fs_mgr_flags.first_stage_mount;
+                                       }),
+                        fstab.end());
         } else {
-            LOG(INFO) << "Failed to read fstab from device tree";
+            LOG(INFO) << "Failed to fstab for first stage mount";
         }
     }
+    return fstab;
+}
 
+// Class Definitions
+// -----------------
+FirstStageMount::FirstStageMount(Fstab fstab)
+    : need_dm_verity_(false), fstab_(std::move(fstab)), uevent_listener_(16 * 1024 * 1024) {
     auto boot_devices = fs_mgr_get_boot_devices();
     device_handler_ = std::make_unique<DeviceHandler>(
             std::vector<Permissions>{}, std::vector<SysfsPermissions>{}, std::vector<Subsystem>{},
@@ -166,15 +165,16 @@
 }
 
 std::unique_ptr<FirstStageMount> FirstStageMount::Create() {
-    if (IsDtVbmetaCompatible()) {
-        return std::make_unique<FirstStageMountVBootV2>();
+    auto fstab = ReadFirstStageFstab();
+    if (IsDtVbmetaCompatible(fstab)) {
+        return std::make_unique<FirstStageMountVBootV2>(std::move(fstab));
     } else {
-        return std::make_unique<FirstStageMountVBootV1>();
+        return std::make_unique<FirstStageMountVBootV1>(std::move(fstab));
     }
 }
 
 bool FirstStageMount::DoFirstStageMount() {
-    if (!IsDmLinearEnabled() && mount_fstab_recs_.empty()) {
+    if (!IsDmLinearEnabled() && fstab_.empty()) {
         // Nothing to mount.
         LOG(INFO) << "First stage mount skipped (missing/incompatible/empty fstab in device tree)";
         return true;
@@ -194,8 +194,8 @@
 }
 
 bool FirstStageMount::IsDmLinearEnabled() {
-    for (auto fstab_rec : mount_fstab_recs_) {
-        if (fs_mgr_is_logical(fstab_rec)) return true;
+    for (const auto& entry : fstab_) {
+        if (entry.fs_mgr_flags.logical) return true;
     }
     return false;
 }
@@ -381,52 +381,90 @@
     return true;
 }
 
-bool FirstStageMount::MountPartition(fstab_rec* fstab_rec) {
-    if (fs_mgr_is_logical(fstab_rec)) {
-        if (!fs_mgr_update_logical_partition(fstab_rec)) {
+bool FirstStageMount::MountPartition(FstabEntry* fstab_entry) {
+    if (fstab_entry->fs_mgr_flags.logical) {
+        if (!fs_mgr_update_logical_partition(fstab_entry)) {
             return false;
         }
-        if (!InitMappedDevice(fstab_rec->blk_device)) {
+        if (!InitMappedDevice(fstab_entry->blk_device)) {
             return false;
         }
     }
-    if (!SetUpDmVerity(fstab_rec)) {
-        PLOG(ERROR) << "Failed to setup verity for '" << fstab_rec->mount_point << "'";
+    if (!SetUpDmVerity(fstab_entry)) {
+        PLOG(ERROR) << "Failed to setup verity for '" << fstab_entry->mount_point << "'";
         return false;
     }
-    if (fs_mgr_do_mount_one(fstab_rec)) {
-        PLOG(ERROR) << "Failed to mount '" << fstab_rec->mount_point << "'";
+    if (fs_mgr_do_mount_one(*fstab_entry)) {
+        PLOG(ERROR) << "Failed to mount '" << fstab_entry->mount_point << "'";
         return false;
     }
     return true;
 }
 
-bool FirstStageMount::MountPartitions() {
-    // If system is in the fstab then we're not a system-as-root device, and in
-    // this case, we mount system first then pivot to it.  From that point on,
-    // we are effectively identical to a system-as-root device.
-    auto system_partition =
-            std::find_if(mount_fstab_recs_.begin(), mount_fstab_recs_.end(),
-                         [](const auto& rec) { return rec->mount_point == "/system"s; });
+// If system is in the fstab then we're not a system-as-root device, and in
+// this case, we mount system first then pivot to it.  From that point on,
+// we are effectively identical to a system-as-root device.
+bool FirstStageMount::TrySwitchSystemAsRoot() {
+    auto system_partition = std::find_if(fstab_.begin(), fstab_.end(), [](const auto& entry) {
+        return entry.mount_point == "/system";
+    });
 
-    if (system_partition != mount_fstab_recs_.end()) {
-        if (!MountPartition(*system_partition)) {
+    if (system_partition != fstab_.end()) {
+        if (!MountPartition(&(*system_partition))) {
             return false;
         }
 
-        SwitchRoot((*system_partition)->mount_point);
+        SwitchRoot((*system_partition).mount_point);
 
-        mount_fstab_recs_.erase(system_partition);
+        fstab_.erase(system_partition);
     }
 
-    for (auto fstab_rec : mount_fstab_recs_) {
-        if (!MountPartition(fstab_rec) && !fs_mgr_is_nofail(fstab_rec)) {
+    return true;
+}
+
+// For GSI to skip mounting /product and /product_services, until there are
+// well-defined interfaces between them and /system. Otherwise, the GSI flashed
+// on /system might not be able to work with /product and /product_services.
+// When they're skipped here, /system/product and /system/product_services in
+// GSI will be used.
+bool FirstStageMount::TrySkipMountingPartitions() {
+    constexpr const char kSkipMountConfig[] = "/system/etc/init/config/skip_mount.cfg";
+
+    std::string skip_config;
+    if (!ReadFileToString(kSkipMountConfig, &skip_config)) {
+        return true;
+    }
+
+    for (const auto& skip_mount_point : Split(skip_config, "\n")) {
+        if (skip_mount_point.empty()) {
+            continue;
+        }
+        auto removing_entry =
+                std::find_if(fstab_.begin(), fstab_.end(), [&skip_mount_point](const auto& entry) {
+                    return entry.mount_point == skip_mount_point;
+                });
+        if (removing_entry != fstab_.end()) {
+            fstab_.erase(removing_entry);
+            LOG(INFO) << "Skip mounting partition: " << skip_mount_point;
+        }
+    }
+
+    return true;
+}
+
+bool FirstStageMount::MountPartitions() {
+    if (!TrySwitchSystemAsRoot()) return false;
+
+    if (!TrySkipMountingPartitions()) return false;
+
+    for (auto& fstab_entry : fstab_) {
+        if (!MountPartition(&fstab_entry) && !fstab_entry.fs_mgr_flags.no_fail) {
             return false;
         }
     }
 
     // heads up for instantiating required device(s) for overlayfs logic
-    const auto devices = fs_mgr_overlayfs_required_devices(mount_fstab_recs_);
+    const auto devices = fs_mgr_overlayfs_required_devices(&fstab_);
     for (auto const& device : devices) {
         if (android::base::StartsWith(device, "/dev/block/by-name/")) {
             required_devices_partition_names_.emplace(basename(device.c_str()));
@@ -438,7 +476,7 @@
         }
     }
 
-    fs_mgr_overlayfs_mount_all(mount_fstab_recs_);
+    fs_mgr_overlayfs_mount_all(&fstab_);
 
     return true;
 }
@@ -447,25 +485,25 @@
     std::string verity_loc_device;
     need_dm_verity_ = false;
 
-    for (auto fstab_rec : mount_fstab_recs_) {
+    for (const auto& fstab_entry : fstab_) {
         // Don't allow verifyatboot in the first stage.
-        if (fs_mgr_is_verifyatboot(fstab_rec)) {
+        if (fstab_entry.fs_mgr_flags.verify_at_boot) {
             LOG(ERROR) << "Partitions can't be verified at boot";
             return false;
         }
         // Checks for verified partitions.
-        if (fs_mgr_is_verified(fstab_rec)) {
+        if (fstab_entry.fs_mgr_flags.verify) {
             need_dm_verity_ = true;
         }
         // Checks if verity metadata is on a separate partition. Note that it is
         // not partition specific, so there must be only one additional partition
         // that carries verity state.
-        if (fstab_rec->verity_loc) {
+        if (!fstab_entry.verity_loc.empty()) {
             if (verity_loc_device.empty()) {
-                verity_loc_device = fstab_rec->verity_loc;
-            } else if (verity_loc_device != fstab_rec->verity_loc) {
+                verity_loc_device = fstab_entry.verity_loc;
+            } else if (verity_loc_device != fstab_entry.verity_loc) {
                 LOG(ERROR) << "More than one verity_loc found: " << verity_loc_device << ", "
-                           << fstab_rec->verity_loc;
+                           << fstab_entry.verity_loc;
                 return false;
             }
         }
@@ -473,9 +511,9 @@
 
     // Includes the partition names of fstab records and verity_loc_device (if any).
     // Notes that fstab_rec->blk_device has A/B suffix updated by fs_mgr when A/B is used.
-    for (auto fstab_rec : mount_fstab_recs_) {
-        if (!fs_mgr_is_logical(fstab_rec)) {
-            required_devices_partition_names_.emplace(basename(fstab_rec->blk_device));
+    for (const auto& fstab_entry : fstab_) {
+        if (!fstab_entry.fs_mgr_flags.logical) {
+            required_devices_partition_names_.emplace(basename(fstab_entry.blk_device.c_str()));
         }
     }
 
@@ -486,19 +524,19 @@
     return true;
 }
 
-bool FirstStageMountVBootV1::SetUpDmVerity(fstab_rec* fstab_rec) {
-    if (fs_mgr_is_verified(fstab_rec)) {
-        int ret = fs_mgr_setup_verity(fstab_rec, false /* wait_for_verity_dev */);
+bool FirstStageMountVBootV1::SetUpDmVerity(FstabEntry* fstab_entry) {
+    if (fstab_entry->fs_mgr_flags.verify) {
+        int ret = fs_mgr_setup_verity(fstab_entry, false /* wait_for_verity_dev */);
         switch (ret) {
             case FS_MGR_SETUP_VERITY_SKIPPED:
             case FS_MGR_SETUP_VERITY_DISABLED:
-                LOG(INFO) << "Verity disabled/skipped for '" << fstab_rec->mount_point << "'";
+                LOG(INFO) << "Verity disabled/skipped for '" << fstab_entry->mount_point << "'";
                 return true;
             case FS_MGR_SETUP_VERITY_SUCCESS:
                 // The exact block device name (fstab_rec->blk_device) is changed to
                 // "/dev/block/dm-XX". Needs to create it because ueventd isn't started in init
                 // first stage.
-                return InitMappedDevice(fstab_rec->blk_device);
+                return InitMappedDevice(fstab_entry->blk_device);
             default:
                 return false;
         }
@@ -506,22 +544,27 @@
     return true;  // Returns true to mount the partition.
 }
 
-// FirstStageMountVBootV2 constructor.
-// Gets the vbmeta partitions from device tree.
-// /{
-//     firmware {
-//         android {
-//             vbmeta {
-//                 compatible = "android,vbmeta";
-//                 parts = "vbmeta,boot,system,vendor"
-//             };
-//         };
-//     };
-//  }
-FirstStageMountVBootV2::FirstStageMountVBootV2() : avb_handle_(nullptr) {
-    if (!read_android_dt_file("vbmeta/parts", &device_tree_vbmeta_parts_)) {
-        PLOG(ERROR) << "Failed to read vbmeta/parts from device tree";
-        return;
+// First retrieve any vbmeta partitions from device tree (legacy) then read through the fstab
+// for any further vbmeta partitions.
+FirstStageMountVBootV2::FirstStageMountVBootV2(Fstab fstab)
+    : FirstStageMount(std::move(fstab)), avb_handle_(nullptr) {
+    std::string device_tree_vbmeta_parts;
+    read_android_dt_file("vbmeta/parts", &device_tree_vbmeta_parts);
+
+    for (auto&& partition : Split(device_tree_vbmeta_parts, ",")) {
+        if (!partition.empty()) {
+            vbmeta_partitions_.emplace_back(std::move(partition));
+        }
+    }
+
+    for (const auto& entry : fstab_) {
+        if (!entry.vbmeta_partition.empty()) {
+            vbmeta_partitions_.emplace_back(entry.vbmeta_partition);
+        }
+    }
+
+    if (vbmeta_partitions_.empty()) {
+        LOG(ERROR) << "Failed to read vbmeta partitions.";
     }
 }
 
@@ -531,30 +574,27 @@
     std::set<std::string> logical_partitions;
 
     // fstab_rec->blk_device has A/B suffix.
-    for (auto fstab_rec : mount_fstab_recs_) {
-        if (fs_mgr_is_avb(fstab_rec)) {
+    for (const auto& fstab_entry : fstab_) {
+        if (fstab_entry.fs_mgr_flags.avb) {
             need_dm_verity_ = true;
         }
-        if (fs_mgr_is_logical(fstab_rec)) {
+        if (fstab_entry.fs_mgr_flags.logical) {
             // Don't try to find logical partitions via uevent regeneration.
-            logical_partitions.emplace(basename(fstab_rec->blk_device));
+            logical_partitions.emplace(basename(fstab_entry.blk_device.c_str()));
         } else {
-            required_devices_partition_names_.emplace(basename(fstab_rec->blk_device));
+            required_devices_partition_names_.emplace(basename(fstab_entry.blk_device.c_str()));
         }
     }
 
-    // libavb verifies AVB metadata on all verified partitions at once.
-    // e.g., The device_tree_vbmeta_parts_ will be "vbmeta,boot,system,vendor"
-    // for libavb to verify metadata, even if there is only /vendor in the
-    // above mount_fstab_recs_.
+    // Any partitions needed for verifying the partitions used in first stage mount, e.g. vbmeta
+    // must be provided as vbmeta_partitions.
     if (need_dm_verity_) {
-        if (device_tree_vbmeta_parts_.empty()) {
-            LOG(ERROR) << "Missing vbmeta parts in device tree";
+        if (vbmeta_partitions_.empty()) {
+            LOG(ERROR) << "Missing vbmeta partitions";
             return false;
         }
-        std::vector<std::string> partitions = android::base::Split(device_tree_vbmeta_parts_, ",");
         std::string ab_suffix = fs_mgr_get_slot_suffix();
-        for (const auto& partition : partitions) {
+        for (const auto& partition : vbmeta_partitions_) {
             std::string partition_name = partition + ab_suffix;
             if (logical_partitions.count(partition_name)) {
                 continue;
@@ -569,11 +609,11 @@
     return true;
 }
 
-bool FirstStageMountVBootV2::SetUpDmVerity(fstab_rec* fstab_rec) {
-    if (fs_mgr_is_avb(fstab_rec)) {
+bool FirstStageMountVBootV2::SetUpDmVerity(FstabEntry* fstab_entry) {
+    if (fstab_entry->fs_mgr_flags.avb) {
         if (!InitAvbHandle()) return false;
         AvbHashtreeResult hashtree_result =
-                avb_handle_->SetUpAvbHashtree(fstab_rec, false /* wait_for_verity_dev */);
+                avb_handle_->SetUpAvbHashtree(fstab_entry, false /* wait_for_verity_dev */);
         switch (hashtree_result) {
             case AvbHashtreeResult::kDisabled:
                 return true;  // Returns true to mount the partition.
@@ -581,7 +621,7 @@
                 // The exact block device name (fstab_rec->blk_device) is changed to
                 // "/dev/block/dm-XX". Needs to create it because ueventd isn't started in init
                 // first stage.
-                return InitMappedDevice(fstab_rec->blk_device);
+                return InitMappedDevice(fstab_entry->blk_device);
             default:
                 return false;
         }
@@ -627,7 +667,9 @@
         return;
     }
 
-    if (!IsDtVbmetaCompatible()) {
+    auto fstab = ReadFirstStageFstab();
+
+    if (!IsDtVbmetaCompatible(fstab)) {
         LOG(INFO) << "Skipped setting INIT_AVB_VERSION (not vbmeta compatible)";
         return;
     }
@@ -637,7 +679,7 @@
     // We only set INIT_AVB_VERSION when the AVB verification succeeds, i.e., the
     // Open() function returns a valid handle.
     // We don't need to mount partitions here in recovery mode.
-    FirstStageMountVBootV2 avb_first_mount;
+    FirstStageMountVBootV2 avb_first_mount(std::move(fstab));
     if (!avb_first_mount.InitDevices()) {
         LOG(ERROR) << "Failed to init devices for INIT_AVB_VERSION";
         return;
diff --git a/init/selinux.cpp b/init/selinux.cpp
index 3a09096..04ca207 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -306,6 +306,11 @@
     }
     std::string mapping_file("/system/etc/selinux/mapping/" + vend_plat_vers + ".cil");
 
+    std::string product_policy_cil_file("/product/etc/selinux/product_sepolicy.cil");
+    if (access(product_policy_cil_file.c_str(), F_OK) == -1) {
+        product_policy_cil_file.clear();
+    }
+
     // vendor_sepolicy.cil and plat_pub_versioned.cil are the new design to replace
     // nonplat_sepolicy.cil.
     std::string plat_pub_versioned_cil_file("/vendor/etc/selinux/plat_pub_versioned.cil");
@@ -342,6 +347,9 @@
     };
     // clang-format on
 
+    if (!product_policy_cil_file.empty()) {
+        compile_args.push_back(product_policy_cil_file.c_str());
+    }
     if (!plat_pub_versioned_cil_file.empty()) {
         compile_args.push_back(plat_pub_versioned_cil_file.c_str());
     }
diff --git a/libappfuse/FuseBridgeLoop.cc b/libappfuse/FuseBridgeLoop.cc
index 8b0c53e..ac94e69 100644
--- a/libappfuse/FuseBridgeLoop.cc
+++ b/libappfuse/FuseBridgeLoop.cc
@@ -311,7 +311,7 @@
 };
 
 FuseBridgeLoop::FuseBridgeLoop() : opened_(true) {
-    base::unique_fd epoll_fd(epoll_create1(/* no flag */ 0));
+    base::unique_fd epoll_fd(epoll_create1(EPOLL_CLOEXEC));
     if (epoll_fd.get() == -1) {
         PLOG(ERROR) << "Failed to open FD for epoll";
         opened_ = false;
diff --git a/libbacktrace/BacktraceCurrent.cpp b/libbacktrace/BacktraceCurrent.cpp
index 39cb995..038b59e 100644
--- a/libbacktrace/BacktraceCurrent.cpp
+++ b/libbacktrace/BacktraceCurrent.cpp
@@ -76,7 +76,7 @@
     return UnwindFromContext(num_ignore_frames, ucontext);
   }
 
-  if (Tid() != android::base::GetThreadId()) {
+  if (Tid() != static_cast<pid_t>(android::base::GetThreadId())) {
     return UnwindThread(num_ignore_frames);
   }
 
diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index fe28eba..f5f9b2a 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -117,7 +117,7 @@
     back_frame->map.name = frame->map_name;
     back_frame->map.start = frame->map_start;
     back_frame->map.end = frame->map_end;
-    back_frame->map.offset = frame->map_offset;
+    back_frame->map.offset = frame->map_elf_start_offset;
     back_frame->map.load_bias = frame->map_load_bias;
     back_frame->map.flags = frame->map_flags;
   }
diff --git a/libcutils/fs_config.cpp b/libcutils/fs_config.cpp
index db59569..1490fbc 100644
--- a/libcutils/fs_config.cpp
+++ b/libcutils/fs_config.cpp
@@ -84,7 +84,7 @@
     { 00750, AID_ROOT,         AID_SHELL,        0, "sbin" },
     { 00777, AID_ROOT,         AID_ROOT,         0, "sdcard" },
     { 00751, AID_ROOT,         AID_SDCARD_R,     0, "storage" },
-    { 00751, AID_ROOT,         AID_SHELL,        0, "system/bin" },
+    { 00755, AID_ROOT,         AID_SHELL,        0, "system/bin" },
     { 00755, AID_ROOT,         AID_ROOT,         0, "system/etc/ppp" },
     { 00755, AID_ROOT,         AID_SHELL,        0, "system/vendor" },
     { 00751, AID_ROOT,         AID_SHELL,        0, "system/xbin" },
diff --git a/libcutils/include/cutils/partition_utils.h b/libcutils/include/cutils/partition_utils.h
index 7518559..8bc9b48 100644
--- a/libcutils/include/cutils/partition_utils.h
+++ b/libcutils/include/cutils/partition_utils.h
@@ -21,7 +21,7 @@
 
 __BEGIN_DECLS
 
-int partition_wiped(char *source);
+int partition_wiped(const char* source);
 
 __END_DECLS
 
diff --git a/libcutils/include/private/android_filesystem_config.h b/libcutils/include/private/android_filesystem_config.h
index 68bf898..0723612 100644
--- a/libcutils/include/private/android_filesystem_config.h
+++ b/libcutils/include/private/android_filesystem_config.h
@@ -133,6 +133,7 @@
 #define AID_LLKD 1070            /* live lock daemon */
 #define AID_IORAPD 1071          /* input/output readahead and pin daemon */
 #define AID_GPU_SERVICE 1072     /* GPU service daemon */
+#define AID_NETWORK_STACK 1073   /* network stack service */
 /* Changes to this file must be made in AOSP, *not* in internal branches. */
 
 #define AID_SHELL 2000 /* adb and debug shell user */
diff --git a/libcutils/partition_utils.cpp b/libcutils/partition_utils.cpp
index 2211ff6..b840559 100644
--- a/libcutils/partition_utils.cpp
+++ b/libcutils/partition_utils.cpp
@@ -39,8 +39,7 @@
     return ret;
 }
 
-int partition_wiped(char *source)
-{
+int partition_wiped(const char* source) {
     uint8_t buf[4096];
     int fd, ret;
 
@@ -67,4 +66,3 @@
 
     return 0;
 }
-
diff --git a/libmeminfo/include/meminfo/sysmeminfo.h b/libmeminfo/include/meminfo/sysmeminfo.h
index 885be1d..f18ae08 100644
--- a/libmeminfo/include/meminfo/sysmeminfo.h
+++ b/libmeminfo/include/meminfo/sysmeminfo.h
@@ -18,6 +18,7 @@
 
 #include <sys/types.h>
 
+#include <functional>
 #include <map>
 #include <string>
 #include <vector>
@@ -51,6 +52,9 @@
     bool ReadMemInfo(const std::string& path = "/proc/meminfo");
     bool ReadMemInfo(const std::vector<std::string>& tags,
                      const std::string& path = "/proc/meminfo");
+    bool ReadMemInfo(const std::vector<std::string>& tags, std::vector<uint64_t>* out,
+                     const std::string& path = "/proc/meminfo");
+    bool ReadMemInfo(std::vector<uint64_t>* out, const std::string& path = "/proc/meminfo");
 
     // getters
     uint64_t mem_total_kb() { return mem_in_kb_[kMemTotal]; }
@@ -59,19 +63,21 @@
     uint64_t mem_cached_kb() { return mem_in_kb_[kMemCached]; }
     uint64_t mem_shmem_kb() { return mem_in_kb_[kMemShmem]; }
     uint64_t mem_slab_kb() { return mem_in_kb_[kMemSlab]; }
-    uint64_t mem_slab_reclailmable_kb() { return mem_in_kb_[kMemSReclaim]; }
+    uint64_t mem_slab_reclaimable_kb() { return mem_in_kb_[kMemSReclaim]; }
     uint64_t mem_slab_unreclaimable_kb() { return mem_in_kb_[kMemSUnreclaim]; }
     uint64_t mem_swap_kb() { return mem_in_kb_[kMemSwapTotal]; }
     uint64_t mem_swap_free_kb() { return mem_in_kb_[kMemSwapFree]; }
     uint64_t mem_mapped_kb() { return mem_in_kb_[kMemMapped]; }
     uint64_t mem_vmalloc_used_kb() { return mem_in_kb_[kMemVmallocUsed]; }
     uint64_t mem_page_tables_kb() { return mem_in_kb_[kMemPageTables]; }
-    uint64_t mem_kernel_stack_kb() { return mem_in_kb_[kMemPageTables]; }
+    uint64_t mem_kernel_stack_kb() { return mem_in_kb_[kMemKernelStack]; }
     uint64_t mem_zram_kb(const std::string& zram_dev = "");
 
   private:
     std::map<std::string, uint64_t> mem_in_kb_;
     bool MemZramDevice(const std::string& zram_dev, uint64_t* mem_zram_dev);
+    bool ReadMemInfo(const std::vector<std::string>& tags, const std::string& path,
+                     std::function<void(const std::string&, uint64_t)> store_val);
 };
 
 }  // namespace meminfo
diff --git a/libmeminfo/libmeminfo_benchmark.cpp b/libmeminfo/libmeminfo_benchmark.cpp
index 1db0824..2660a4d 100644
--- a/libmeminfo/libmeminfo_benchmark.cpp
+++ b/libmeminfo/libmeminfo_benchmark.cpp
@@ -29,6 +29,8 @@
 
 #include <benchmark/benchmark.h>
 
+using ::android::meminfo::SysMemInfo;
+
 enum {
     MEMINFO_TOTAL,
     MEMINFO_FREE,
@@ -71,8 +73,7 @@
     static const char* const tags[] = {
             "MemTotal:",     "MemFree:",    "Buffers:",     "Cached:",   "Shmem:", "Slab:",
             "SReclaimable:", "SUnreclaim:", "SwapTotal:",   "SwapFree:", "ZRam:",  "Mapped:",
-            "VmallocUsed:",  "PageTables:", "KernelStack:", NULL
-    };
+            "VmallocUsed:",  "PageTables:", "KernelStack:", NULL};
 
     static const int tagsLen[] = {9, 8, 8, 7, 6, 5, 13, 11, 10, 9, 5, 7, 12, 11, 12, 0};
 
@@ -105,7 +106,7 @@
     }
 }
 
-static void BM_ParseSysMemInfo(benchmark::State& state) {
+static void BM_ReadMemInfo_old(benchmark::State& state) {
     std::string meminfo = R"meminfo(MemTotal:        3019740 kB
 MemFree:         1809728 kB
 MemAvailable:    2546560 kB
@@ -159,9 +160,9 @@
         get_mem_info(mem, tf.path);
     }
 }
-BENCHMARK(BM_ParseSysMemInfo);
+BENCHMARK(BM_ReadMemInfo_old);
 
-static void BM_ReadMemInfo(benchmark::State& state) {
+static void BM_ReadMemInfo_new(benchmark::State& state) {
     std::string meminfo = R"meminfo(MemTotal:        3019740 kB
 MemFree:         1809728 kB
 MemAvailable:    2546560 kB
@@ -211,12 +212,21 @@
     android::base::WriteStringToFd(meminfo, tf.fd);
 
     std::string file = std::string(tf.path);
-    ::android::meminfo::SysMemInfo mi;
+    std::vector<uint64_t> mem(MEMINFO_COUNT);
+    const std::vector<std::string> tags = {
+            SysMemInfo::kMemTotal,      SysMemInfo::kMemFree,        SysMemInfo::kMemBuffers,
+            SysMemInfo::kMemCached,     SysMemInfo::kMemShmem,       SysMemInfo::kMemSlab,
+            SysMemInfo::kMemSReclaim,   SysMemInfo::kMemSUnreclaim,  SysMemInfo::kMemSwapTotal,
+            SysMemInfo::kMemSwapFree,   SysMemInfo::kMemMapped,      SysMemInfo::kMemVmallocUsed,
+            SysMemInfo::kMemPageTables, SysMemInfo::kMemKernelStack,
+    };
+
+    SysMemInfo smi;
     for (auto _ : state) {
-        mi.ReadMemInfo(file);
+        smi.ReadMemInfo(tags, &mem, file);
     }
 }
-BENCHMARK(BM_ReadMemInfo);
+BENCHMARK(BM_ReadMemInfo_new);
 
 static uint64_t get_zram_mem_used(const std::string& zram_dir) {
     FILE* f = fopen((zram_dir + "mm_stat").c_str(), "r");
@@ -246,23 +256,145 @@
     return 0;
 }
 
-static void BM_OldReadZramTotal(benchmark::State& state) {
+static void BM_ZramTotal_old(benchmark::State& state) {
     std::string exec_dir = ::android::base::GetExecutableDirectory();
     std::string zram_mmstat_dir = exec_dir + "/testdata1/";
     for (auto _ : state) {
         uint64_t zram_total __attribute__((unused)) = get_zram_mem_used(zram_mmstat_dir) / 1024;
     }
 }
-BENCHMARK(BM_OldReadZramTotal);
+BENCHMARK(BM_ZramTotal_old);
 
-static void BM_NewReadZramTotal(benchmark::State& state) {
+static void BM_ZramTotal_new(benchmark::State& state) {
     std::string exec_dir = ::android::base::GetExecutableDirectory();
     std::string zram_mmstat_dir = exec_dir + "/testdata1/";
-    ::android::meminfo::SysMemInfo mi;
+    SysMemInfo smi;
     for (auto _ : state) {
-        uint64_t zram_total __attribute__((unused)) = mi.mem_zram_kb(zram_mmstat_dir);
+        uint64_t zram_total __attribute__((unused)) = smi.mem_zram_kb(zram_mmstat_dir);
     }
 }
-BENCHMARK(BM_NewReadZramTotal);
+BENCHMARK(BM_ZramTotal_new);
+
+static void BM_MemInfoWithZram_old(benchmark::State& state) {
+    std::string meminfo = R"meminfo(MemTotal:        3019740 kB
+MemFree:         1809728 kB
+MemAvailable:    2546560 kB
+Buffers:           54736 kB
+Cached:           776052 kB
+SwapCached:            0 kB
+Active:           445856 kB
+Inactive:         459092 kB
+Active(anon):      78492 kB
+Inactive(anon):     2240 kB
+Active(file):     367364 kB
+Inactive(file):   456852 kB
+Unevictable:        3096 kB
+Mlocked:            3096 kB
+SwapTotal:             0 kB
+SwapFree:              0 kB
+Dirty:                32 kB
+Writeback:             0 kB
+AnonPages:         74988 kB
+Mapped:            62624 kB
+Shmem:              4020 kB
+Slab:              86464 kB
+SReclaimable:      44432 kB
+SUnreclaim:        42032 kB
+KernelStack:        4880 kB
+PageTables:         2900 kB
+NFS_Unstable:          0 kB
+Bounce:                0 kB
+WritebackTmp:          0 kB
+CommitLimit:     1509868 kB
+Committed_AS:      80296 kB
+VmallocTotal:   263061440 kB
+VmallocUsed:           0 kB
+VmallocChunk:          0 kB
+AnonHugePages:      6144 kB
+ShmemHugePages:        0 kB
+ShmemPmdMapped:        0 kB
+CmaTotal:         131072 kB
+CmaFree:          130380 kB
+HugePages_Total:       0
+HugePages_Free:        0
+HugePages_Rsvd:        0
+HugePages_Surp:        0
+Hugepagesize:       2048 kB)meminfo";
+
+    TemporaryFile tf;
+    ::android::base::WriteStringToFd(meminfo, tf.fd);
+    std::string exec_dir = ::android::base::GetExecutableDirectory();
+    std::string zram_mmstat_dir = exec_dir + "/testdata1/";
+    uint64_t mem[MEMINFO_COUNT];
+    for (auto _ : state) {
+        get_mem_info(mem, tf.path);
+        mem[MEMINFO_ZRAM_TOTAL] = get_zram_mem_used("/sys/block/zram0/") / 1024;
+        CHECK_EQ(mem[MEMINFO_KERNEL_STACK], 4880u);
+    }
+}
+BENCHMARK(BM_MemInfoWithZram_old);
+
+static void BM_MemInfoWithZram_new(benchmark::State& state) {
+    std::string meminfo = R"meminfo(MemTotal:        3019740 kB
+MemFree:         1809728 kB
+MemAvailable:    2546560 kB
+Buffers:           54736 kB
+Cached:           776052 kB
+SwapCached:            0 kB
+Active:           445856 kB
+Inactive:         459092 kB
+Active(anon):      78492 kB
+Inactive(anon):     2240 kB
+Active(file):     367364 kB
+Inactive(file):   456852 kB
+Unevictable:        3096 kB
+Mlocked:            3096 kB
+SwapTotal:             0 kB
+SwapFree:              0 kB
+Dirty:                32 kB
+Writeback:             0 kB
+AnonPages:         74988 kB
+Mapped:            62624 kB
+Shmem:              4020 kB
+Slab:              86464 kB
+SReclaimable:      44432 kB
+SUnreclaim:        42032 kB
+KernelStack:        4880 kB
+PageTables:         2900 kB
+NFS_Unstable:          0 kB
+Bounce:                0 kB
+WritebackTmp:          0 kB
+CommitLimit:     1509868 kB
+Committed_AS:      80296 kB
+VmallocTotal:   263061440 kB
+VmallocUsed:           0 kB
+VmallocChunk:          0 kB
+AnonHugePages:      6144 kB
+ShmemHugePages:        0 kB
+ShmemPmdMapped:        0 kB
+CmaTotal:         131072 kB
+CmaFree:          130380 kB
+HugePages_Total:       0
+HugePages_Free:        0
+HugePages_Rsvd:        0
+HugePages_Surp:        0
+Hugepagesize:       2048 kB)meminfo";
+
+    TemporaryFile tf;
+    android::base::WriteStringToFd(meminfo, tf.fd);
+
+    std::string file = std::string(tf.path);
+    std::vector<uint64_t> mem(MEMINFO_COUNT);
+    std::vector<std::string> tags(SysMemInfo::kDefaultSysMemInfoTags);
+    auto it = tags.begin();
+    tags.insert(it + MEMINFO_ZRAM_TOTAL, "Zram:");
+    SysMemInfo smi;
+
+    for (auto _ : state) {
+        smi.ReadMemInfo(tags, &mem, file);
+        CHECK_EQ(mem[MEMINFO_KERNEL_STACK], 4880u);
+    }
+}
+BENCHMARK(BM_MemInfoWithZram_new);
 
 BENCHMARK_MAIN();
diff --git a/libmeminfo/libmeminfo_test.cpp b/libmeminfo/libmeminfo_test.cpp
index b7a4b6b..2856c2d 100644
--- a/libmeminfo/libmeminfo_test.cpp
+++ b/libmeminfo/libmeminfo_test.cpp
@@ -347,8 +347,8 @@
 Inactive(file):   456852 kB
 Unevictable:        3096 kB
 Mlocked:            3096 kB
-SwapTotal:             0 kB
-SwapFree:              0 kB
+SwapTotal:         32768 kB
+SwapFree:           4096 kB
 Dirty:                32 kB
 Writeback:             0 kB
 AnonPages:         74988 kB
@@ -365,7 +365,7 @@
 CommitLimit:     1509868 kB
 Committed_AS:      80296 kB
 VmallocTotal:   263061440 kB
-VmallocUsed:           0 kB
+VmallocUsed:       65536 kB
 VmallocChunk:          0 kB
 AnonHugePages:      6144 kB
 ShmemHugePages:        0 kB
@@ -385,7 +385,19 @@
     SysMemInfo mi;
     ASSERT_TRUE(mi.ReadMemInfo(tf.path));
     EXPECT_EQ(mi.mem_total_kb(), 3019740);
+    EXPECT_EQ(mi.mem_free_kb(), 1809728);
+    EXPECT_EQ(mi.mem_buffers_kb(), 54736);
+    EXPECT_EQ(mi.mem_cached_kb(), 776052);
+    EXPECT_EQ(mi.mem_shmem_kb(), 4020);
+    EXPECT_EQ(mi.mem_slab_kb(), 86464);
+    EXPECT_EQ(mi.mem_slab_reclaimable_kb(), 44432);
+    EXPECT_EQ(mi.mem_slab_unreclaimable_kb(), 42032);
+    EXPECT_EQ(mi.mem_swap_kb(), 32768);
+    EXPECT_EQ(mi.mem_swap_free_kb(), 4096);
+    EXPECT_EQ(mi.mem_mapped_kb(), 62624);
+    EXPECT_EQ(mi.mem_vmalloc_used_kb(), 65536);
     EXPECT_EQ(mi.mem_page_tables_kb(), 2900);
+    EXPECT_EQ(mi.mem_kernel_stack_kb(), 4880);
 }
 
 TEST(SysMemInfoParser, TestEmptyFile) {
@@ -399,7 +411,7 @@
     EXPECT_EQ(mi.mem_total_kb(), 0);
 }
 
-TEST(SysMemInfoParse, TestZramTotal) {
+TEST(SysMemInfoParser, TestZramTotal) {
     std::string exec_dir = ::android::base::GetExecutableDirectory();
 
     SysMemInfo mi;
@@ -410,6 +422,100 @@
     EXPECT_EQ(mi.mem_zram_kb(zram_memused_dir), 30504);
 }
 
+enum {
+    MEMINFO_TOTAL,
+    MEMINFO_FREE,
+    MEMINFO_BUFFERS,
+    MEMINFO_CACHED,
+    MEMINFO_SHMEM,
+    MEMINFO_SLAB,
+    MEMINFO_SLAB_RECLAIMABLE,
+    MEMINFO_SLAB_UNRECLAIMABLE,
+    MEMINFO_SWAP_TOTAL,
+    MEMINFO_SWAP_FREE,
+    MEMINFO_ZRAM_TOTAL,
+    MEMINFO_MAPPED,
+    MEMINFO_VMALLOC_USED,
+    MEMINFO_PAGE_TABLES,
+    MEMINFO_KERNEL_STACK,
+    MEMINFO_COUNT
+};
+
+TEST(SysMemInfoParser, TestZramWithTags) {
+    std::string meminfo = R"meminfo(MemTotal:        3019740 kB
+MemFree:         1809728 kB
+MemAvailable:    2546560 kB
+Buffers:           54736 kB
+Cached:           776052 kB
+SwapCached:            0 kB
+Active:           445856 kB
+Inactive:         459092 kB
+Active(anon):      78492 kB
+Inactive(anon):     2240 kB
+Active(file):     367364 kB
+Inactive(file):   456852 kB
+Unevictable:        3096 kB
+Mlocked:            3096 kB
+SwapTotal:         32768 kB
+SwapFree:           4096 kB
+Dirty:                32 kB
+Writeback:             0 kB
+AnonPages:         74988 kB
+Mapped:            62624 kB
+Shmem:              4020 kB
+Slab:              86464 kB
+SReclaimable:      44432 kB
+SUnreclaim:        42032 kB
+KernelStack:        4880 kB
+PageTables:         2900 kB
+NFS_Unstable:          0 kB
+Bounce:                0 kB
+WritebackTmp:          0 kB
+CommitLimit:     1509868 kB
+Committed_AS:      80296 kB
+VmallocTotal:   263061440 kB
+VmallocUsed:       65536 kB
+VmallocChunk:          0 kB
+AnonHugePages:      6144 kB
+ShmemHugePages:        0 kB
+ShmemPmdMapped:        0 kB
+CmaTotal:         131072 kB
+CmaFree:          130380 kB
+HugePages_Total:       0
+HugePages_Free:        0
+HugePages_Rsvd:        0
+HugePages_Surp:        0
+Hugepagesize:       2048 kB)meminfo";
+
+    TemporaryFile tf;
+    ASSERT_TRUE(tf.fd != -1);
+    ASSERT_TRUE(::android::base::WriteStringToFd(meminfo, tf.fd));
+    std::string file = std::string(tf.path);
+    std::vector<uint64_t> mem(MEMINFO_COUNT);
+    std::vector<std::string> tags(SysMemInfo::kDefaultSysMemInfoTags);
+    auto it = tags.begin();
+    tags.insert(it + MEMINFO_ZRAM_TOTAL, "Zram:");
+    SysMemInfo mi;
+
+    // Read system memory info
+    EXPECT_TRUE(mi.ReadMemInfo(tags, &mem, file));
+
+    EXPECT_EQ(mem[MEMINFO_TOTAL], 3019740);
+    EXPECT_EQ(mem[MEMINFO_FREE], 1809728);
+    EXPECT_EQ(mem[MEMINFO_BUFFERS], 54736);
+    EXPECT_EQ(mem[MEMINFO_CACHED], 776052);
+    EXPECT_EQ(mem[MEMINFO_SHMEM], 4020);
+    EXPECT_EQ(mem[MEMINFO_SLAB], 86464);
+    EXPECT_EQ(mem[MEMINFO_SLAB_RECLAIMABLE], 44432);
+    EXPECT_EQ(mem[MEMINFO_SLAB_UNRECLAIMABLE], 42032);
+    EXPECT_EQ(mem[MEMINFO_SWAP_TOTAL], 32768);
+    EXPECT_EQ(mem[MEMINFO_SWAP_FREE], 4096);
+    EXPECT_EQ(mem[MEMINFO_MAPPED], 62624);
+    EXPECT_EQ(mem[MEMINFO_VMALLOC_USED], 65536);
+    EXPECT_EQ(mem[MEMINFO_PAGE_TABLES], 2900);
+    EXPECT_EQ(mem[MEMINFO_KERNEL_STACK], 4880);
+}
+
 int main(int argc, char** argv) {
     ::testing::InitGoogleTest(&argc, argv);
     if (argc <= 1) {
diff --git a/libmeminfo/sysmeminfo.cpp b/libmeminfo/sysmeminfo.cpp
index 7e56238..4ec1c99 100644
--- a/libmeminfo/sysmeminfo.cpp
+++ b/libmeminfo/sysmeminfo.cpp
@@ -18,12 +18,15 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <algorithm>
 #include <cctype>
 #include <cstdio>
 #include <fstream>
+#include <iterator>
 #include <string>
 #include <utility>
 #include <vector>
@@ -49,7 +52,29 @@
 };
 
 bool SysMemInfo::ReadMemInfo(const std::string& path) {
-    return ReadMemInfo(SysMemInfo::kDefaultSysMemInfoTags, path);
+    return ReadMemInfo(SysMemInfo::kDefaultSysMemInfoTags, path,
+                       [&](const std::string& tag, uint64_t val) { mem_in_kb_[tag] = val; });
+}
+
+bool SysMemInfo::ReadMemInfo(std::vector<uint64_t>* out, const std::string& path) {
+    return ReadMemInfo(SysMemInfo::kDefaultSysMemInfoTags, out, path);
+}
+
+bool SysMemInfo::ReadMemInfo(const std::vector<std::string>& tags, std::vector<uint64_t>* out,
+                             const std::string& path) {
+    out->clear();
+    out->resize(tags.size());
+
+    return ReadMemInfo(tags, path, [&]([[maybe_unused]] const std::string& tag, uint64_t val) {
+        auto it = std::find(tags.begin(), tags.end(), tag);
+        if (it == tags.end()) {
+            LOG(ERROR) << "Tried to store invalid tag: " << tag;
+            return;
+        }
+        auto index = std::distance(tags.begin(), it);
+        // store the values in the same order as the tags
+        out->at(index) = val;
+    });
 }
 
 // TODO: Delete this function if it can't match up with the c-like implementation below.
@@ -88,7 +113,8 @@
 }
 
 #else
-bool SysMemInfo::ReadMemInfo(const std::vector<std::string>& tags, const std::string& path) {
+bool SysMemInfo::ReadMemInfo(const std::vector<std::string>& tags, const std::string& path,
+                             std::function<void(const std::string&, uint64_t)> store_val) {
     char buffer[4096];
     int fd = open(path.c_str(), O_RDONLY | O_CLOEXEC);
     if (fd < 0) {
@@ -106,22 +132,34 @@
     char* p = buffer;
     uint32_t found = 0;
     uint32_t lineno = 0;
+    bool zram_tag_found = false;
     while (*p && found < tags.size()) {
         for (auto& tag : tags) {
+            // Special case for "Zram:" tag that android_os_Debug and friends look
+            // up along with the rest of the numbers from /proc/meminfo
+            if (!zram_tag_found && tag == "Zram:") {
+                store_val(tag, mem_zram_kb());
+                zram_tag_found = true;
+                found++;
+                continue;
+            }
+
             if (strncmp(p, tag.c_str(), tag.size()) == 0) {
                 p += tag.size();
                 while (*p == ' ') p++;
                 char* endptr = nullptr;
-                mem_in_kb_[tag] = strtoull(p, &endptr, 10);
+                uint64_t val = strtoull(p, &endptr, 10);
                 if (p == endptr) {
                     PLOG(ERROR) << "Failed to parse line:" << lineno + 1 << " in file: " << path;
                     return false;
                 }
+                store_val(tag, val);
                 p = endptr;
                 found++;
                 break;
             }
         }
+
         while (*p && *p != '\n') {
             p++;
         }
@@ -163,24 +201,19 @@
 }
 
 bool SysMemInfo::MemZramDevice(const std::string& zram_dev, uint64_t* mem_zram_dev) {
-    std::string content;
-    if (android::base::ReadFileToString(zram_dev + "mm_stat", &content)) {
-        std::vector<std::string> values = ::android::base::Split(content, " ");
-        if (values.size() < 3) {
-            LOG(ERROR) << "Malformed mm_stat file for zram dev: " << zram_dev
-                       << " content: " << content;
+    std::string mmstat = ::android::base::StringPrintf("%s/%s", zram_dev.c_str(), "mm_stat");
+    auto mmstat_fp = std::unique_ptr<FILE, decltype(&fclose)>{fopen(mmstat.c_str(), "re"), fclose};
+    if (mmstat_fp != nullptr) {
+        // only if we do have mmstat, use it. Otherwise, fall through to trying out the old
+        // 'mem_used_total'
+        if (fscanf(mmstat_fp.get(), "%*" SCNu64 " %*" SCNu64 " %" SCNu64, mem_zram_dev) != 1) {
+            PLOG(ERROR) << "Malformed mm_stat file in: " << zram_dev;
             return false;
         }
-
-        if (!::android::base::ParseUint(values[2], mem_zram_dev)) {
-            LOG(ERROR) << "Malformed mm_stat file for zram dev: " << zram_dev
-                       << " value: " << values[2];
-            return false;
-        }
-
         return true;
     }
 
+    std::string content;
     if (::android::base::ReadFileToString(zram_dev + "mem_used_total", &content)) {
         *mem_zram_dev = strtoull(content.c_str(), NULL, 10);
         if (*mem_zram_dev == ULLONG_MAX) {
diff --git a/libmeminfo/testdata1/mm_stat b/libmeminfo/testdata1/mm_stat
index 684f567..32b325f 100644
--- a/libmeminfo/testdata1/mm_stat
+++ b/libmeminfo/testdata1/mm_stat
@@ -1 +1 @@
-145674240 26801454 31236096        0 45772800     3042     1887      517
+ 145674240 26801454 31236096        0 45772800     3042     1887      517
diff --git a/libmetricslogger/include/metricslogger/metrics_logger.h b/libmetricslogger/include/metricslogger/metrics_logger.h
index 56bd6c4..71c04a6 100644
--- a/libmetricslogger/include/metricslogger/metrics_logger.h
+++ b/libmetricslogger/include/metricslogger/metrics_logger.h
@@ -116,7 +116,7 @@
     FIELD_BATTERY_RESISTANCE_UOHMS = 1448,
     FIELD_BATTERY_CURRENT_UA = 1449,
     FIELD_HARDWARE_LOCATION = 1450,
-    ACTION_BATTERY_CAUSED_SHUTDOWN = 1441,
+    ACTION_BATTERY_CAUSED_SHUTDOWN = 1451,
 };
 
 enum {
diff --git a/libnativeloader/native_loader.cpp b/libnativeloader/native_loader.cpp
index b3e2b97..de7ea08 100644
--- a/libnativeloader/native_loader.cpp
+++ b/libnativeloader/native_loader.cpp
@@ -639,7 +639,11 @@
   UNUSED(target_sdk_version);
   if (class_loader == nullptr) {
     *needs_native_bridge = false;
-    return dlopen(path, RTLD_NOW);
+    void* handle = dlopen(path, RTLD_NOW);
+    if (handle == nullptr) {
+      *error_msg = dlerror();
+    }
+    return handle;
   }
 
   std::lock_guard<std::mutex> guard(g_namespaces_mutex);
diff --git a/libpixelflinger/codeflinger/CodeCache.cpp b/libpixelflinger/codeflinger/CodeCache.cpp
index 8516640..32691a3 100644
--- a/libpixelflinger/codeflinger/CodeCache.cpp
+++ b/libpixelflinger/codeflinger/CodeCache.cpp
@@ -61,7 +61,11 @@
 #define USAGE_ERROR_ACTION(m,p) \
     heap_error("ARGUMENT IS INVALID HEAP ADDRESS", __FUNCTION__, p)
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wexpansion-to-defined"
+#pragma GCC diagnostic ignored "-Wnull-pointer-arithmetic"
 #include "../../../../external/dlmalloc/malloc.c"
+#pragma GCC diagnostic pop
 
 static void heap_error(const char* msg, const char* function, void* p) {
     ALOG(LOG_FATAL, LOG_TAG, "@@@ ABORTING: CODE FLINGER: %s IN %s addr=%p",
diff --git a/libsparse/output_file.cpp b/libsparse/output_file.cpp
index fe314b3..5b8179f 100644
--- a/libsparse/output_file.cpp
+++ b/libsparse/output_file.cpp
@@ -508,7 +508,7 @@
 
   out->len = len;
   out->block_size = block_size;
-  out->cur_out_ptr = 0ll;
+  out->cur_out_ptr = 0LL;
   out->chunk_cnt = 0;
   out->crc32 = 0;
   out->use_crc = crc;
diff --git a/libstats/include/stats_event_list.h b/libstats/include/stats_event_list.h
index 41ca79b..162d1cf 100644
--- a/libstats/include/stats_event_list.h
+++ b/libstats/include/stats_event_list.h
@@ -24,7 +24,7 @@
 #endif
 void reset_log_context(android_log_context ctx);
 int write_to_logger(android_log_context context, log_id_t id);
-void note_log_drop();
+void note_log_drop(int error);
 void stats_log_close();
 int android_log_write_char_array(android_log_context ctx, const char* value, size_t len);
 #ifdef __cplusplus
diff --git a/libstats/stats_event_list.c b/libstats/stats_event_list.c
index f4a7e94..5b90361 100644
--- a/libstats/stats_event_list.c
+++ b/libstats/stats_event_list.c
@@ -120,8 +120,8 @@
     return retValue;
 }
 
-void note_log_drop() {
-    statsdLoggerWrite.noteDrop();
+void note_log_drop(int error) {
+    statsdLoggerWrite.noteDrop(error);
 }
 
 void stats_log_close() {
diff --git a/libstats/statsd_writer.c b/libstats/statsd_writer.c
index 88f7d44..f00fc2d 100644
--- a/libstats/statsd_writer.c
+++ b/libstats/statsd_writer.c
@@ -48,6 +48,7 @@
 
 static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
 static atomic_int dropped = 0;
+static atomic_int log_error = 0;
 
 void statsd_writer_init_lock() {
     /*
@@ -150,8 +151,9 @@
     return 1;
 }
 
-static void statsdNoteDrop() {
+static void statsdNoteDrop(int error) {
     atomic_fetch_add_explicit(&dropped, 1, memory_order_relaxed);
+    atomic_exchange_explicit(&log_error, error, memory_order_relaxed);
 }
 
 static int statsdWrite(struct timespec* ts, struct iovec* vec, size_t nr) {
@@ -202,7 +204,8 @@
         if (snapshot) {
             android_log_event_int_t buffer;
             header.id = LOG_ID_STATS;
-            buffer.header.tag = htole32(LIBLOG_LOG_TAG);
+            // store the last log error in the tag field. This tag field is not used by statsd.
+            buffer.header.tag = htole32(atomic_load(&log_error));
             buffer.payload.type = EVENT_TYPE_INT;
             buffer.payload.data = htole32(snapshot);
 
diff --git a/libstats/statsd_writer.h b/libstats/statsd_writer.h
index 7289441..4fc3f8b 100644
--- a/libstats/statsd_writer.h
+++ b/libstats/statsd_writer.h
@@ -39,7 +39,7 @@
     /* write log to transport, returns number of bytes propagated, or -errno */
     int (*write)(struct timespec* ts, struct iovec* vec, size_t nr);
     /* note one log drop */
-    void (*noteDrop)();
+    void (*noteDrop)(int error);
 };
 
 #endif  // ANDROID_STATS_LOG_STATS_WRITER_H
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index a5e0dc9..89d4fc0 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -94,7 +94,10 @@
                 "DexFile.cpp",
                 "DexFiles.cpp",
             ],
-            exclude_shared_libs: ["libdexfile"],
+            exclude_shared_libs: [
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
         },
         recovery: {
             cflags: ["-DNO_LIBDEXFILE_SUPPORT"],
@@ -102,7 +105,10 @@
                 "DexFile.cpp",
                 "DexFiles.cpp",
             ],
-            exclude_shared_libs: ["libdexfile"],
+            exclude_shared_libs: [
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
         },
     },
 
@@ -127,7 +133,8 @@
 
     shared_libs: [
         "libbase",
-        "libdexfile",
+        "libdexfile_external",
+        "libdexfile_support",
         "liblog",
         "liblzma",
     ],
@@ -215,6 +222,7 @@
         "liblzma",
         "libunwindstack",
         "libdexfile",
+        "libdexfile_support",
     ],
 
     static_libs: [
@@ -235,6 +243,8 @@
         "tests/files/offline/jit_map_arm/*",
         "tests/files/offline/gnu_debugdata_arm/*",
         "tests/files/offline/offset_arm/*",
+        "tests/files/offline/shared_lib_in_apk_arm64/*",
+        "tests/files/offline/shared_lib_in_apk_memory_only_arm64/*",
         "tests/files/offline/straddle_arm/*",
         "tests/files/offline/straddle_arm64/*",
     ],
diff --git a/libunwindstack/DexFile.cpp b/libunwindstack/DexFile.cpp
index 8ec560c..9b0b232 100644
--- a/libunwindstack/DexFile.cpp
+++ b/libunwindstack/DexFile.cpp
@@ -23,13 +23,7 @@
 #include <memory>
 
 #include <android-base/unique_fd.h>
-
-#include <dex/class_accessor-inl.h>
-#include <dex/code_item_accessors-inl.h>
-#include <dex/compact_dex_file.h>
-#include <dex/dex_file-inl.h>
-#include <dex/dex_file_loader.h>
-#include <dex/standard_dex_file.h>
+#include <art_api/ext_dex_file.h>
 
 #include <unwindstack/MapInfo.h>
 #include <unwindstack/Memory.h>
@@ -38,169 +32,71 @@
 
 namespace unwindstack {
 
-DexFile* DexFile::Create(uint64_t dex_file_offset_in_memory, Memory* memory, MapInfo* info) {
+std::unique_ptr<DexFile> DexFile::Create(uint64_t dex_file_offset_in_memory, Memory* memory,
+                                         MapInfo* info) {
   if (!info->name.empty()) {
-    std::unique_ptr<DexFileFromFile> dex_file(new DexFileFromFile);
-    if (dex_file->Open(dex_file_offset_in_memory - info->start + info->offset, info->name)) {
-      return dex_file.release();
+    std::unique_ptr<DexFile> dex_file =
+        DexFileFromFile::Create(dex_file_offset_in_memory - info->start + info->offset, info->name);
+    if (dex_file) {
+      return dex_file;
     }
   }
-
-  std::unique_ptr<DexFileFromMemory> dex_file(new DexFileFromMemory);
-  if (dex_file->Open(dex_file_offset_in_memory, memory)) {
-    return dex_file.release();
-  }
-  return nullptr;
-}
-
-DexFileFromFile::~DexFileFromFile() {
-  if (size_ != 0) {
-    munmap(mapped_memory_, size_);
-  }
+  return DexFileFromMemory::Create(dex_file_offset_in_memory, memory, info->name);
 }
 
 bool DexFile::GetMethodInformation(uint64_t dex_offset, std::string* method_name,
                                    uint64_t* method_offset) {
-  if (dex_file_ == nullptr) {
+  art_api::dex::MethodInfo method_info = GetMethodInfoForOffset(dex_offset);
+  if (method_info.offset == 0) {
     return false;
   }
-
-  if (!dex_file_->IsInDataSection(dex_file_->Begin() + dex_offset)) {
-    return false;  // The DEX offset is not within the bytecode of this dex file.
-  }
-
-  if (dex_file_->IsCompactDexFile()) {
-    // The data section of compact dex files might be shared.
-    // Check the subrange unique to this compact dex.
-    const auto& cdex_header = dex_file_->AsCompactDexFile()->GetHeader();
-    uint32_t begin = cdex_header.data_off_ + cdex_header.OwnedDataBegin();
-    uint32_t end = cdex_header.data_off_ + cdex_header.OwnedDataEnd();
-    if (dex_offset < begin || dex_offset >= end) {
-      return false;  // The DEX offset is not within the bytecode of this dex file.
-    }
-  }
-
-  // The method data is cached in a std::map indexed by method end offset and
-  // contains the start offset and the method member index.
-  // Only cache the method data as it is searched. Do not read the entire
-  // set of method data into the cache at once.
-  // This is done because many unwinds only find a single frame with dex file
-  // info, so reading the entire method data is wasteful. However, still cache
-  // the data so that anything doing multiple unwinds will have this data
-  // cached for future use.
-
-  // First look in the method cache.
-  auto entry = method_cache_.upper_bound(dex_offset);
-  if (entry != method_cache_.end() && dex_offset >= entry->second.first) {
-    *method_name = dex_file_->PrettyMethod(entry->second.second, false);
-    *method_offset = dex_offset - entry->second.first;
-    return true;
-  }
-
-  // Check the methods we haven't cached.
-  for (; class_def_index_ < dex_file_->NumClassDefs(); class_def_index_++) {
-    art::ClassAccessor accessor(*dex_file_, dex_file_->GetClassDef(class_def_index_));
-
-    for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
-      art::CodeItemInstructionAccessor code = method.GetInstructions();
-      if (!code.HasCodeItem()) {
-        continue;
-      }
-      uint32_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - dex_file_->Begin();
-      uint32_t offset_end = offset + code.InsnsSizeInBytes();
-      uint32_t member_index = method.GetIndex();
-      method_cache_[offset_end] = std::make_pair(offset, member_index);
-      if (offset <= dex_offset && dex_offset < offset_end) {
-        *method_name = dex_file_->PrettyMethod(member_index, false);
-        *method_offset = dex_offset - offset;
-        return true;
-      }
-    }
-  }
-  return false;
+  *method_name = method_info.name;
+  *method_offset = dex_offset - method_info.offset;
+  return true;
 }
 
-bool DexFileFromFile::Open(uint64_t dex_file_offset_in_file, const std::string& file) {
+std::unique_ptr<DexFileFromFile> DexFileFromFile::Create(uint64_t dex_file_offset_in_file,
+                                                         const std::string& file) {
   android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(file.c_str(), O_RDONLY | O_CLOEXEC)));
   if (fd == -1) {
-    return false;
-  }
-  struct stat buf;
-  if (fstat(fd, &buf) == -1) {
-    return false;
-  }
-  uint64_t length;
-  if (buf.st_size < 0 ||
-      __builtin_add_overflow(dex_file_offset_in_file, sizeof(art::DexFile::Header), &length) ||
-      static_cast<uint64_t>(buf.st_size) < length) {
-    return false;
+    return nullptr;
   }
 
-  mapped_memory_ = mmap(nullptr, buf.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-  if (mapped_memory_ == MAP_FAILED) {
-    return false;
-  }
-  size_ = buf.st_size;
-
-  uint8_t* memory = reinterpret_cast<uint8_t*>(mapped_memory_);
-
-  art::DexFile::Header* header =
-      reinterpret_cast<art::DexFile::Header*>(&memory[dex_file_offset_in_file]);
-  if (!art::StandardDexFile::IsMagicValid(header->magic_) &&
-      !art::CompactDexFile::IsMagicValid(header->magic_)) {
-    return false;
-  }
-
-  if (__builtin_add_overflow(dex_file_offset_in_file, header->file_size_, &length) ||
-      static_cast<uint64_t>(buf.st_size) < length) {
-    return false;
-  }
-
-  art::DexFileLoader loader;
   std::string error_msg;
-  auto dex = loader.Open(&memory[dex_file_offset_in_file], header->file_size_, "", 0, nullptr,
-                         false, false, &error_msg);
-  dex_file_.reset(dex.release());
-  return dex_file_ != nullptr;
+  std::unique_ptr<art_api::dex::DexFile> art_dex_file =
+      OpenFromFd(fd, dex_file_offset_in_file, file, &error_msg);
+  if (art_dex_file == nullptr) {
+    return nullptr;
+  }
+
+  return std::unique_ptr<DexFileFromFile>(new DexFileFromFile(std::move(*art_dex_file.release())));
 }
 
-bool DexFileFromMemory::Open(uint64_t dex_file_offset_in_memory, Memory* memory) {
-  memory_.resize(sizeof(art::DexFile::Header));
-  if (!memory->ReadFully(dex_file_offset_in_memory, memory_.data(), memory_.size())) {
-    return false;
-  }
+std::unique_ptr<DexFileFromMemory> DexFileFromMemory::Create(uint64_t dex_file_offset_in_memory,
+                                                             Memory* memory,
+                                                             const std::string& name) {
+  std::vector<uint8_t> backing_memory;
 
-  art::DexFile::Header* header = reinterpret_cast<art::DexFile::Header*>(memory_.data());
-  uint32_t file_size = header->file_size_;
-  if (art::CompactDexFile::IsMagicValid(header->magic_)) {
-    // Compact dex file store data section separately so that it can be shared.
-    // Therefore we need to extend the read memory range to include it.
-    // TODO: This might be wasteful as we might read data in between as well.
-    //       In practice, this should be fine, as such sharing only happens on disk.
-    uint32_t computed_file_size;
-    if (__builtin_add_overflow(header->data_off_, header->data_size_, &computed_file_size)) {
-      return false;
+  for (size_t size = 0;;) {
+    std::string error_msg;
+    std::unique_ptr<art_api::dex::DexFile> art_dex_file =
+        OpenFromMemory(backing_memory.data(), &size, name, &error_msg);
+
+    if (art_dex_file != nullptr) {
+      return std::unique_ptr<DexFileFromMemory>(
+          new DexFileFromMemory(std::move(*art_dex_file.release()), std::move(backing_memory)));
     }
-    if (computed_file_size > file_size) {
-      file_size = computed_file_size;
+
+    if (!error_msg.empty()) {
+      return nullptr;
     }
-  } else if (!art::StandardDexFile::IsMagicValid(header->magic_)) {
-    return false;
+
+    backing_memory.resize(size);
+    if (!memory->ReadFully(dex_file_offset_in_memory, backing_memory.data(),
+                           backing_memory.size())) {
+      return nullptr;
+    }
   }
-
-  memory_.resize(file_size);
-  if (!memory->ReadFully(dex_file_offset_in_memory, memory_.data(), memory_.size())) {
-    return false;
-  }
-
-  header = reinterpret_cast<art::DexFile::Header*>(memory_.data());
-
-  art::DexFileLoader loader;
-  std::string error_msg;
-  auto dex =
-      loader.Open(memory_.data(), header->file_size_, "", 0, nullptr, false, false, &error_msg);
-  dex_file_.reset(dex.release());
-  return dex_file_ != nullptr;
 }
 
 }  // namespace unwindstack
diff --git a/libunwindstack/DexFile.h b/libunwindstack/DexFile.h
index c123158..5797dee 100644
--- a/libunwindstack/DexFile.h
+++ b/libunwindstack/DexFile.h
@@ -25,48 +25,41 @@
 #include <utility>
 #include <vector>
 
-#include <dex/dex_file-inl.h>
+#include <art_api/ext_dex_file.h>
 
 namespace unwindstack {
 
-class DexFile {
+class DexFile : protected art_api::dex::DexFile {
  public:
-  DexFile() = default;
   virtual ~DexFile() = default;
 
   bool GetMethodInformation(uint64_t dex_offset, std::string* method_name, uint64_t* method_offset);
 
-  static DexFile* Create(uint64_t dex_file_offset_in_memory, Memory* memory, MapInfo* info);
+  static std::unique_ptr<DexFile> Create(uint64_t dex_file_offset_in_memory, Memory* memory,
+                                         MapInfo* info);
 
  protected:
-  void Init();
-
-  std::unique_ptr<const art::DexFile> dex_file_;
-  std::map<uint32_t, std::pair<uint64_t, uint32_t>> method_cache_;  // dex offset to method index.
-
-  uint32_t class_def_index_ = 0;
+  DexFile(art_api::dex::DexFile&& art_dex_file) : art_api::dex::DexFile(std::move(art_dex_file)) {}
 };
 
 class DexFileFromFile : public DexFile {
  public:
-  DexFileFromFile() = default;
-  virtual ~DexFileFromFile();
-
-  bool Open(uint64_t dex_file_offset_in_file, const std::string& name);
+  static std::unique_ptr<DexFileFromFile> Create(uint64_t dex_file_offset_in_file,
+                                                 const std::string& file);
 
  private:
-  void* mapped_memory_ = nullptr;
-  size_t size_ = 0;
+  DexFileFromFile(art_api::dex::DexFile&& art_dex_file) : DexFile(std::move(art_dex_file)) {}
 };
 
 class DexFileFromMemory : public DexFile {
  public:
-  DexFileFromMemory() = default;
-  virtual ~DexFileFromMemory() = default;
-
-  bool Open(uint64_t dex_file_offset_in_memory, Memory* memory);
+  static std::unique_ptr<DexFileFromMemory> Create(uint64_t dex_file_offset_in_memory,
+                                                   Memory* memory, const std::string& name);
 
  private:
+  DexFileFromMemory(art_api::dex::DexFile&& art_dex_file, std::vector<uint8_t>&& memory)
+      : DexFile(std::move(art_dex_file)), memory_(std::move(memory)) {}
+
   std::vector<uint8_t> memory_;
 };
 
diff --git a/libunwindstack/DexFiles.cpp b/libunwindstack/DexFiles.cpp
index 451a0b9..63a77e5 100644
--- a/libunwindstack/DexFiles.cpp
+++ b/libunwindstack/DexFiles.cpp
@@ -48,11 +48,7 @@
 DexFiles::DexFiles(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)
     : Global(memory, search_libs) {}
 
-DexFiles::~DexFiles() {
-  for (auto& entry : files_) {
-    delete entry.second;
-  }
-}
+DexFiles::~DexFiles() {}
 
 void DexFiles::ProcessArch() {
   switch (arch()) {
@@ -137,10 +133,11 @@
   DexFile* dex_file;
   auto entry = files_.find(dex_file_offset);
   if (entry == files_.end()) {
-    dex_file = DexFile::Create(dex_file_offset, memory_.get(), info);
-    files_[dex_file_offset] = dex_file;
+    std::unique_ptr<DexFile> new_dex_file = DexFile::Create(dex_file_offset, memory_.get(), info);
+    dex_file = new_dex_file.get();
+    files_[dex_file_offset] = std::move(new_dex_file);
   } else {
-    dex_file = entry->second;
+    dex_file = entry->second.get();
   }
   return dex_file;
 }
diff --git a/libunwindstack/DwarfCfa.cpp b/libunwindstack/DwarfCfa.cpp
index 0fa1638..4ba8a4b 100644
--- a/libunwindstack/DwarfCfa.cpp
+++ b/libunwindstack/DwarfCfa.cpp
@@ -260,7 +260,7 @@
   }
 
   // Log any of the expression data.
-  for (const auto line : expression_lines) {
+  for (const auto& line : expression_lines) {
     log(indent + 1, "%s", line.c_str());
   }
   return true;
diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index e3b48ca..39a09cf 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -29,6 +29,32 @@
 
 namespace unwindstack {
 
+bool MapInfo::InitFileMemoryFromPreviousReadOnlyMap(MemoryFileAtOffset* memory) {
+  // One last attempt, see if the previous map is read-only with the
+  // same name and stretches across this map.
+  if (prev_map == nullptr || prev_map->flags != PROT_READ) {
+    return false;
+  }
+
+  uint64_t map_size = end - prev_map->end;
+  if (!memory->Init(name, prev_map->offset, map_size)) {
+    return false;
+  }
+
+  uint64_t max_size;
+  if (!Elf::GetInfo(memory, &max_size) || max_size < map_size) {
+    return false;
+  }
+
+  if (!memory->Init(name, prev_map->offset, max_size)) {
+    return false;
+  }
+
+  elf_offset = offset - prev_map->offset;
+  elf_start_offset = prev_map->offset;
+  return true;
+}
+
 Memory* MapInfo::GetFileMemory() {
   std::unique_ptr<MemoryFileAtOffset> memory(new MemoryFileAtOffset);
   if (offset == 0) {
@@ -38,8 +64,12 @@
     return nullptr;
   }
 
-  // There are two possibilities when the offset is non-zero.
-  // - There is an elf file embedded in a file.
+  // These are the possibilities when the offset is non-zero.
+  // - There is an elf file embedded in a file, and the offset is the
+  //   the start of the elf in the file.
+  // - There is an elf file embedded in a file, and the offset is the
+  //   the start of the executable part of the file. The actual start
+  //   of the elf is in the read-only segment preceeding this map.
   // - The whole file is an elf file, and the offset needs to be saved.
   //
   // Map in just the part of the file for the map. If this is not
@@ -53,27 +83,47 @@
     return nullptr;
   }
 
-  uint64_t max_size;
-  if (!Elf::GetInfo(memory.get(), &max_size)) {
-    // Init as if the whole file is an elf.
-    if (memory->Init(name, 0)) {
-      elf_offset = offset;
-      return memory.release();
+  // Check if the start of this map is an embedded elf.
+  uint64_t max_size = 0;
+  if (Elf::GetInfo(memory.get(), &max_size)) {
+    if (max_size > map_size) {
+      if (memory->Init(name, offset, max_size)) {
+        return memory.release();
+      }
+      // Try to reinit using the default map_size.
+      if (memory->Init(name, offset, map_size)) {
+        return memory.release();
+      }
+      return nullptr;
     }
-    return nullptr;
+    return memory.release();
   }
 
-  if (max_size > map_size) {
-    if (memory->Init(name, offset, max_size)) {
-      return memory.release();
+  // No elf at offset, try to init as if the whole file is an elf.
+  if (memory->Init(name, 0) && Elf::IsValidElf(memory.get())) {
+    elf_offset = offset;
+    // Need to check how to set the elf start offset. If this map is not
+    // the r-x map of a r-- map, then use the real offset value. Otherwise,
+    // use 0.
+    if (prev_map == nullptr || prev_map->offset != 0 || prev_map->flags != PROT_READ ||
+        prev_map->name != name) {
+      elf_start_offset = offset;
     }
-    // Try to reinit using the default map_size.
-    if (memory->Init(name, offset, map_size)) {
-      return memory.release();
-    }
-    return nullptr;
+    return memory.release();
   }
-  return memory.release();
+
+  // See if the map previous to this one contains a read-only map
+  // that represents the real start of the elf data.
+  if (InitFileMemoryFromPreviousReadOnlyMap(memory.get())) {
+    return memory.release();
+  }
+
+  // Failed to find elf at start of file or at read-only map, return
+  // file object from the current map.
+  if (memory->Init(name, offset, map_size)) {
+    return memory.release();
+  }
+  return nullptr;
 }
 
 Memory* MapInfo::CreateMemory(const std::shared_ptr<Memory>& process_memory) {
@@ -106,37 +156,24 @@
     return memory.release();
   }
 
-  if (name.empty() || maps_ == nullptr) {
-    return nullptr;
-  }
-
-  // Find the read-only map that has the same name and has an offset closest
-  // to the current offset but less than the offset of the current map.
-  // For shared libraries, there should be a r-x map that has a non-zero
-  // offset and then a r-- map that has a zero offset.
-  // For shared libraries loaded from an apk, there should be a r-x map that
-  // has a non-zero offset and then a r-- map that has a non-zero offset less
-  // than the offset from the r-x map.
-  uint64_t closest_offset = 0;
-  MapInfo* ro_map_info = nullptr;
-  for (auto map_info : *maps_) {
-    if (map_info->flags == PROT_READ && map_info->name == name && map_info->offset < offset &&
-        map_info->offset >= closest_offset) {
-      ro_map_info = map_info;
-      closest_offset = ro_map_info->offset;
-    }
-  }
-
-  if (ro_map_info == nullptr) {
+  // Find the read-only map by looking at the previous map. The linker
+  // doesn't guarantee that this invariant will always be true. However,
+  // if that changes, there is likely something else that will change and
+  // break something.
+  if (offset == 0 || name.empty() || prev_map == nullptr || prev_map->name != name ||
+      prev_map->offset >= offset) {
     return nullptr;
   }
 
   // Make sure that relative pc values are corrected properly.
-  elf_offset = offset - closest_offset;
+  elf_offset = offset - prev_map->offset;
+  // Use this as the elf start offset, otherwise, you always get offsets into
+  // the r-x section, which is not quite the right information.
+  elf_start_offset = prev_map->offset;
 
   MemoryRanges* ranges = new MemoryRanges;
-  ranges->Insert(new MemoryRange(process_memory, ro_map_info->start,
-                                 ro_map_info->end - ro_map_info->start, 0));
+  ranges->Insert(
+      new MemoryRange(process_memory, prev_map->start, prev_map->end - prev_map->start, 0));
   ranges->Insert(new MemoryRange(process_memory, start, end - start, elf_offset));
 
   return ranges;
diff --git a/libunwindstack/Maps.cpp b/libunwindstack/Maps.cpp
index a9fb859..c90e383 100644
--- a/libunwindstack/Maps.cpp
+++ b/libunwindstack/Maps.cpp
@@ -67,13 +67,15 @@
         if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
           flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
         }
-        maps_.push_back(new MapInfo(this, start, end, pgoff, flags, name));
+        maps_.push_back(
+            new MapInfo(maps_.empty() ? nullptr : maps_.back(), start, end, pgoff, flags, name));
       });
 }
 
 void Maps::Add(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
                const std::string& name, uint64_t load_bias) {
-  MapInfo* map_info = new MapInfo(this, start, end, offset, flags, name);
+  MapInfo* map_info =
+      new MapInfo(maps_.empty() ? nullptr : maps_.back(), start, end, offset, flags, name);
   map_info->load_bias = load_bias;
   maps_.push_back(map_info);
 }
@@ -81,6 +83,13 @@
 void Maps::Sort() {
   std::sort(maps_.begin(), maps_.end(),
             [](const MapInfo* a, const MapInfo* b) { return a->start < b->start; });
+
+  // Set the prev_map values on the info objects.
+  MapInfo* prev_map = nullptr;
+  for (MapInfo* map_info : maps_) {
+    map_info->prev_map = prev_map;
+    prev_map = map_info;
+  }
 }
 
 Maps::~Maps() {
@@ -98,7 +107,8 @@
         if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
           flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
         }
-        maps_.push_back(new MapInfo(this, start, end, pgoff, flags, name));
+        maps_.push_back(
+            new MapInfo(maps_.empty() ? nullptr : maps_.back(), start, end, pgoff, flags, name));
       });
 }
 
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index b3c5549..8133639 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -59,7 +59,8 @@
   if (info != nullptr) {
     frame->map_start = info->start;
     frame->map_end = info->end;
-    frame->map_offset = info->offset;
+    frame->map_elf_start_offset = info->elf_start_offset;
+    frame->map_exact_offset = info->offset;
     frame->map_load_bias = info->load_bias;
     frame->map_flags = info->flags;
     if (resolve_names_) {
@@ -102,7 +103,8 @@
   if (resolve_names_) {
     frame->map_name = map_info->name;
   }
-  frame->map_offset = map_info->offset;
+  frame->map_elf_start_offset = map_info->elf_start_offset;
+  frame->map_exact_offset = map_info->offset;
   frame->map_start = map_info->start;
   frame->map_end = map_info->end;
   frame->map_flags = map_info->flags;
@@ -239,8 +241,14 @@
 
     if (!stepped) {
       if (return_address_attempt) {
-        // Remove the speculative frame.
-        frames_.pop_back();
+        // Only remove the speculative frame if there are more than two frames
+        // or the pc in the first frame is in a valid map.
+        // This allows for a case where the code jumps into the middle of
+        // nowhere, but there is no other unwind information after that.
+        if (frames_.size() != 2 || maps_->Find(frames_[0].pc) != nullptr) {
+          // Remove the speculative frame.
+          frames_.pop_back();
+        }
         break;
       } else if (in_device_map) {
         // Do not attempt any other unwinding, pc or sp is in a device
@@ -284,10 +292,6 @@
     data += android::base::StringPrintf("  #%02zu pc %016" PRIx64, frame.num, frame.rel_pc);
   }
 
-  if (frame.map_offset != 0) {
-    data += android::base::StringPrintf(" (offset 0x%" PRIx64 ")", frame.map_offset);
-  }
-
   if (frame.map_start == frame.map_end) {
     // No valid map associated with this frame.
     data += "  <unknown>";
@@ -296,6 +300,11 @@
   } else {
     data += android::base::StringPrintf("  <anonymous:%" PRIx64 ">", frame.map_start);
   }
+
+  if (frame.map_elf_start_offset != 0) {
+    data += android::base::StringPrintf(" (offset 0x%" PRIx64 ")", frame.map_elf_start_offset);
+  }
+
   if (!frame.function_name.empty()) {
     data += " (" + frame.function_name;
     if (frame.function_offset != 0) {
diff --git a/libunwindstack/include/unwindstack/DexFiles.h b/libunwindstack/include/unwindstack/DexFiles.h
index c202a33..0336173 100644
--- a/libunwindstack/include/unwindstack/DexFiles.h
+++ b/libunwindstack/include/unwindstack/DexFiles.h
@@ -66,7 +66,7 @@
 
   std::mutex lock_;
   bool initialized_ = false;
-  std::unordered_map<uint64_t, DexFile*> files_;
+  std::unordered_map<uint64_t, std::unique_ptr<DexFile>> files_;
 
   uint64_t entry_addr_ = 0;
   uint64_t (DexFiles::*read_entry_ptr_func_)(uint64_t) = nullptr;
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index 9c6b552..5e3d6f6 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -25,38 +25,31 @@
 #include <string>
 
 #include <unwindstack/Elf.h>
+#include <unwindstack/Memory.h>
 
 namespace unwindstack {
 
-// Forward declarations.
-class Maps;
-class Memory;
-
 struct MapInfo {
-  MapInfo(Maps* maps) : maps_(maps) {}
-  MapInfo(Maps* maps, uint64_t start, uint64_t end) : maps_(maps), start(start), end(end) {}
-  MapInfo(Maps* maps, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+  MapInfo(MapInfo* map_info, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
           const char* name)
-      : maps_(maps),
-        start(start),
+      : start(start),
         end(end),
         offset(offset),
         flags(flags),
         name(name),
+        prev_map(map_info),
         load_bias(static_cast<uint64_t>(-1)) {}
-  MapInfo(Maps* maps, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+  MapInfo(MapInfo* map_info, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
           const std::string& name)
-      : maps_(maps),
-        start(start),
+      : start(start),
         end(end),
         offset(offset),
         flags(flags),
         name(name),
+        prev_map(map_info),
         load_bias(static_cast<uint64_t>(-1)) {}
   ~MapInfo() = default;
 
-  Maps* maps_ = nullptr;
-
   uint64_t start = 0;
   uint64_t end = 0;
   uint64_t offset = 0;
@@ -64,10 +57,14 @@
   std::string name;
   std::shared_ptr<Elf> elf;
   // This value is only non-zero if the offset is non-zero but there is
-  // no elf signature found at that offset. This indicates that the
-  // entire file is represented by the Memory object returned by CreateMemory,
-  // instead of a portion of the file.
+  // no elf signature found at that offset.
   uint64_t elf_offset = 0;
+  // This value is the offset from the map in memory that is the start
+  // of the elf. This is not equal to offset when the linker splits
+  // shared libraries into a read-only and read-execute map.
+  uint64_t elf_start_offset = 0;
+
+  MapInfo* prev_map = nullptr;
 
   std::atomic_uint64_t load_bias;
 
@@ -83,6 +80,7 @@
   void operator=(const MapInfo&) = delete;
 
   Memory* GetFileMemory();
+  bool InitFileMemoryFromPreviousReadOnlyMap(MemoryFileAtOffset* memory);
 
   // Protect the creation of the elf object.
   std::mutex mutex_;
diff --git a/libunwindstack/include/unwindstack/Unwinder.h b/libunwindstack/include/unwindstack/Unwinder.h
index 56b0581..d7bbd9d 100644
--- a/libunwindstack/include/unwindstack/Unwinder.h
+++ b/libunwindstack/include/unwindstack/Unwinder.h
@@ -48,7 +48,13 @@
   uint64_t function_offset = 0;
 
   std::string map_name;
-  uint64_t map_offset = 0;
+  // The offset from the first map representing the frame. When there are
+  // two maps (read-only and read-execute) this will be the offset from
+  // the read-only map. When there is only one map, this will be the
+  // same as the actual offset of the map and match map_exact_offset.
+  uint64_t map_elf_start_offset = 0;
+  // The actual offset from the map where the pc lies.
+  uint64_t map_exact_offset = 0;
   uint64_t map_start = 0;
   uint64_t map_end = 0;
   uint64_t map_load_bias = 0;
diff --git a/libunwindstack/tests/DexFileTest.cpp b/libunwindstack/tests/DexFileTest.cpp
index 95d2176..21ca47b 100644
--- a/libunwindstack/tests/DexFileTest.cpp
+++ b/libunwindstack/tests/DexFileTest.cpp
@@ -21,44 +21,37 @@
 #include <unordered_map>
 
 #include <android-base/file.h>
-
+#include <dex/dex_file.h>
+#include <gtest/gtest.h>
 #include <unwindstack/MapInfo.h>
 #include <unwindstack/Memory.h>
 
-#include <dex/code_item_accessors-inl.h>
-#include <dex/standard_dex_file.h>
-
-#include <gtest/gtest.h>
-
 #include "DexFile.h"
-
 #include "DexFileData.h"
 #include "MemoryFake.h"
 
 namespace unwindstack {
 
 TEST(DexFileTest, from_file_open_non_exist) {
-  DexFileFromFile dex_file;
-  ASSERT_FALSE(dex_file.Open(0, "/file/does/not/exist"));
+  EXPECT_TRUE(DexFileFromFile::Create(0, "/file/does/not/exist") == nullptr);
 }
 
 TEST(DexFileTest, from_file_open_too_small) {
   TemporaryFile tf;
   ASSERT_TRUE(tf.fd != -1);
 
-  ASSERT_EQ(sizeof(art::DexFile::Header) - 2,
+  ASSERT_EQ(sizeof(art::DexFile::Header) - 1,
             static_cast<size_t>(
-                TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(art::DexFile::Header)) - 2)));
+                TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(art::DexFile::Header) - 1))));
 
   // Header too small.
-  DexFileFromFile dex_file;
-  ASSERT_FALSE(dex_file.Open(0, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0, tf.path) == nullptr);
 
   // Header correct, file too small.
   ASSERT_EQ(0, lseek(tf.fd, 0, SEEK_SET));
   ASSERT_EQ(sizeof(art::DexFile::Header), static_cast<size_t>(TEMP_FAILURE_RETRY(write(
                                               tf.fd, kDexData, sizeof(art::DexFile::Header)))));
-  ASSERT_FALSE(dex_file.Open(0, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0, tf.path) == nullptr);
 }
 
 TEST(DexFileTest, from_file_open) {
@@ -68,8 +61,7 @@
   ASSERT_EQ(sizeof(kDexData),
             static_cast<size_t>(TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(kDexData)))));
 
-  DexFileFromFile dex_file;
-  ASSERT_TRUE(dex_file.Open(0, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0, tf.path) != nullptr);
 }
 
 TEST(DexFileTest, from_file_open_non_zero_offset) {
@@ -80,35 +72,31 @@
   ASSERT_EQ(sizeof(kDexData),
             static_cast<size_t>(TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(kDexData)))));
 
-  DexFileFromFile dex_file;
-  ASSERT_TRUE(dex_file.Open(0x100, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0x100, tf.path) != nullptr);
 }
 
 TEST(DexFileTest, from_memory_fail_too_small_for_header) {
   MemoryFake memory;
 
   memory.SetMemory(0x1000, kDexData, sizeof(art::DexFile::Header) - 1);
-  DexFileFromMemory dex_file;
 
-  ASSERT_FALSE(dex_file.Open(0x1000, &memory));
+  EXPECT_TRUE(DexFileFromMemory::Create(0x1000, &memory, "") == nullptr);
 }
 
 TEST(DexFileTest, from_memory_fail_too_small_for_data) {
   MemoryFake memory;
 
   memory.SetMemory(0x1000, kDexData, sizeof(kDexData) - 2);
-  DexFileFromMemory dex_file;
 
-  ASSERT_FALSE(dex_file.Open(0x1000, &memory));
+  EXPECT_TRUE(DexFileFromMemory::Create(0x1000, &memory, "") == nullptr);
 }
 
 TEST(DexFileTest, from_memory_open) {
   MemoryFake memory;
 
   memory.SetMemory(0x1000, kDexData, sizeof(kDexData));
-  DexFileFromMemory dex_file;
 
-  ASSERT_TRUE(dex_file.Open(0x1000, &memory));
+  EXPECT_TRUE(DexFileFromMemory::Create(0x1000, &memory, "") != nullptr);
 }
 
 TEST(DexFileTest, create_using_file) {
@@ -121,8 +109,7 @@
 
   MemoryFake memory;
   MapInfo info(nullptr, 0, 0x10000, 0, 0x5, tf.path);
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x500, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x500, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_file_non_zero_start) {
@@ -135,8 +122,7 @@
 
   MemoryFake memory;
   MapInfo info(nullptr, 0x100, 0x10000, 0, 0x5, tf.path);
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x600, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x600, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_file_non_zero_offset) {
@@ -149,24 +135,21 @@
 
   MemoryFake memory;
   MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, tf.path);
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x400, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x400, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_memory_empty_file) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
   MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "");
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x4000, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_memory_file_does_not_exist) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
   MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "/does/not/exist");
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x4000, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_memory_file_is_malformed) {
@@ -179,22 +162,13 @@
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
   MapInfo info(nullptr, 0x4000, 0x10000, 0x200, 0x5, "/does/not/exist");
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
+  std::unique_ptr<DexFile> dex_file = DexFile::Create(0x4000, &memory, &info);
   ASSERT_TRUE(dex_file != nullptr);
 
   // Check it came from memory by clearing memory and verifying it fails.
   memory.Clear();
-  dex_file.reset(DexFile::Create(0x4000, &memory, &info));
-  ASSERT_TRUE(dex_file == nullptr);
-}
-
-TEST(DexFileTest, get_method_not_opened) {
-  std::string method("something");
-  uint64_t method_offset = 100;
-  DexFile dex_file;
-  dex_file.GetMethodInformation(0x100, &method, &method_offset);
-  EXPECT_EQ("something", method);
-  EXPECT_EQ(100U, method_offset);
+  dex_file = DexFile::Create(0x4000, &memory, &info);
+  EXPECT_TRUE(dex_file == nullptr);
 }
 
 TEST(DexFileTest, get_method) {
diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index 7766218..f7689ce 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -269,7 +269,7 @@
   elf.FakeSetInterface(interface);
 
   elf.FakeSetValid(true);
-  MapInfo map_info(nullptr, 0x1000, 0x2000);
+  MapInfo map_info(nullptr, 0x1000, 0x2000, 0, 0, "");
 
   ASSERT_EQ(0x101U, elf.GetRelPc(0x1101, &map_info));
 
diff --git a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
index 0987bc1..a66685a 100644
--- a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
+++ b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
@@ -59,16 +59,16 @@
   }
 
   static void SetUpTestCase() {
-    std::vector<uint8_t> buffer(1024);
-    memset(buffer.data(), 0, buffer.size());
+    std::vector<uint8_t> buffer(12288, 0);
     memcpy(buffer.data(), ELFMAG, SELFMAG);
     buffer[EI_CLASS] = ELFCLASS32;
-    ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
+    ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), 1024));
 
     memset(buffer.data(), 0, buffer.size());
-    memcpy(&buffer[0x100], ELFMAG, SELFMAG);
-    buffer[0x100 + EI_CLASS] = ELFCLASS64;
-    ASSERT_TRUE(android::base::WriteFully(elf_at_100_.fd, buffer.data(), buffer.size()));
+    memcpy(&buffer[0x1000], ELFMAG, SELFMAG);
+    buffer[0x1000 + EI_CLASS] = ELFCLASS64;
+    buffer[0x2000] = 0xff;
+    ASSERT_TRUE(android::base::WriteFully(elf_at_1000_.fd, buffer.data(), buffer.size()));
 
     InitElf<Elf32_Ehdr, Elf32_Shdr>(elf32_at_map_.fd, 0x1000, 0x2000, ELFCLASS32);
     InitElf<Elf64_Ehdr, Elf64_Shdr>(elf64_at_map_.fd, 0x2000, 0x3000, ELFCLASS64);
@@ -84,13 +84,13 @@
 
   static TemporaryFile elf_;
 
-  static TemporaryFile elf_at_100_;
+  static TemporaryFile elf_at_1000_;
 
   static TemporaryFile elf32_at_map_;
   static TemporaryFile elf64_at_map_;
 };
 TemporaryFile MapInfoCreateMemoryTest::elf_;
-TemporaryFile MapInfoCreateMemoryTest::elf_at_100_;
+TemporaryFile MapInfoCreateMemoryTest::elf_at_1000_;
 TemporaryFile MapInfoCreateMemoryTest::elf32_at_map_;
 TemporaryFile MapInfoCreateMemoryTest::elf64_at_map_;
 
@@ -118,6 +118,7 @@
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
 
   // Read the entire file.
   std::vector<uint8_t> buffer(1024);
@@ -129,16 +130,55 @@
   }
 
   ASSERT_FALSE(memory->ReadFully(1024, buffer.data(), 1));
+
+  // Now verify the elf start offset is set correctly based on the previous
+  // info.
+  MapInfo prev_info(nullptr, 0, 0x100, 0x10, 0, "");
+  info.prev_map = &prev_info;
+
+  // No preconditions met, change each one until it should set the elf start
+  // offset to zero.
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
+
+  prev_info.offset = 0;
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
+
+  prev_info.flags = PROT_READ;
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
+
+  prev_info.name = info.name;
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 }
 
 // Verify that if the offset is non-zero and there is an elf at that
 // offset, that only part of the file is used.
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file) {
-  MapInfo info(nullptr, 0x100, 0x200, 0x100, 0, elf_at_100_.path);
+  MapInfo info(nullptr, 0x100, 0x200, 0x1000, 0, elf_at_1000_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 
   // Read the valid part of the file.
   std::vector<uint8_t> buffer(0x100);
@@ -162,6 +202,7 @@
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 
   // Verify the memory is a valid elf.
   uint8_t e_ident[SELFMAG + 1];
@@ -178,6 +219,7 @@
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 
   // Verify the memory is a valid elf.
   uint8_t e_ident[SELFMAG + 1];
@@ -250,6 +292,7 @@
   ASSERT_TRUE(mem.get() != nullptr);
   EXPECT_EQ(0x4000UL, map_info->elf_offset);
   EXPECT_EQ(0x4000UL, map_info->offset);
+  EXPECT_EQ(0U, map_info->elf_start_offset);
 
   // Verify that reading values from this memory works properly.
   std::vector<uint8_t> buffer(0x4000);
@@ -295,6 +338,7 @@
   ASSERT_TRUE(mem.get() != nullptr);
   EXPECT_EQ(0x1000UL, map_info->elf_offset);
   EXPECT_EQ(0xb000UL, map_info->offset);
+  EXPECT_EQ(0xa000UL, map_info->elf_start_offset);
 
   // Verify that reading values from this memory works properly.
   std::vector<uint8_t> buffer(0x4000);
@@ -312,4 +356,45 @@
   }
 }
 
+TEST_F(MapInfoCreateMemoryTest, rosegment_from_file) {
+  Maps maps;
+  maps.Add(0x500, 0x600, 0, PROT_READ, "something_else", 0);
+  maps.Add(0x1000, 0x2000, 0x1000, PROT_READ, elf_at_1000_.path, 0);
+  maps.Add(0x2000, 0x3000, 0x2000, PROT_READ | PROT_EXEC, elf_at_1000_.path, 0);
+
+  MapInfo* map_info = maps.Find(0x2000);
+  ASSERT_TRUE(map_info != nullptr);
+
+  // Set up the size
+  Elf64_Ehdr ehdr;
+  ASSERT_EQ(0x1000, lseek(elf_at_1000_.fd, 0x1000, SEEK_SET));
+  ASSERT_TRUE(android::base::ReadFully(elf_at_1000_.fd, &ehdr, sizeof(ehdr)));
+
+  // Will not give the elf memory, because the read-only entry does not
+  // extend over the executable segment.
+  std::unique_ptr<Memory> memory(map_info->CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  std::vector<uint8_t> buffer(0x100);
+  EXPECT_EQ(0x2000U, map_info->offset);
+  EXPECT_EQ(0U, map_info->elf_offset);
+  EXPECT_EQ(0U, map_info->elf_start_offset);
+  ASSERT_TRUE(memory->ReadFully(0, buffer.data(), 0x100));
+  EXPECT_EQ(0xffU, buffer[0]);
+
+  // Now init the elf data enough so that the file memory object will be used.
+  ehdr.e_shoff = 0x4000;
+  ehdr.e_shnum = 1;
+  ehdr.e_shentsize = 0x100;
+  ASSERT_EQ(0x1000, lseek(elf_at_1000_.fd, 0x1000, SEEK_SET));
+  ASSERT_TRUE(android::base::WriteFully(elf_at_1000_.fd, &ehdr, sizeof(ehdr)));
+
+  memory.reset(map_info->CreateMemory(process_memory_));
+  EXPECT_EQ(0x2000U, map_info->offset);
+  EXPECT_EQ(0x1000U, map_info->elf_offset);
+  EXPECT_EQ(0x1000U, map_info->elf_start_offset);
+  Elf64_Ehdr ehdr_mem;
+  ASSERT_TRUE(memory->ReadFully(0, &ehdr_mem, sizeof(ehdr_mem)));
+  EXPECT_TRUE(memcmp(&ehdr, &ehdr_mem, sizeof(ehdr)) == 0);
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MapsTest.cpp b/libunwindstack/tests/MapsTest.cpp
index 80e292a..b4197f2 100644
--- a/libunwindstack/tests/MapsTest.cpp
+++ b/libunwindstack/tests/MapsTest.cpp
@@ -62,7 +62,7 @@
 }
 
 TEST(MapsTest, verify_parse_line) {
-  MapInfo info(nullptr);
+  MapInfo info(nullptr, 0, 0, 0, 0, "");
 
   VerifyLine("01-02 rwxp 03 04:05 06\n", &info);
   EXPECT_EQ(1U, info.start);
@@ -135,7 +135,7 @@
 }
 
 TEST(MapsTest, verify_large_values) {
-  MapInfo info(nullptr);
+  MapInfo info(nullptr, 0, 0, 0, 0, "");
 #if defined(__LP64__)
   VerifyLine("fabcdef012345678-f12345678abcdef8 rwxp f0b0d0f010305070 00:00 0\n", &info);
   EXPECT_EQ(0xfabcdef012345678UL, info.start);
diff --git a/libunwindstack/tests/RegsTest.cpp b/libunwindstack/tests/RegsTest.cpp
index 00264c2..472d1cf 100644
--- a/libunwindstack/tests/RegsTest.cpp
+++ b/libunwindstack/tests/RegsTest.cpp
@@ -182,7 +182,7 @@
   RegsX86_64 regs_x86_64;
   RegsMips regs_mips;
   RegsMips64 regs_mips64;
-  MapInfo map_info(nullptr, 0x1000, 0x2000);
+  MapInfo map_info(nullptr, 0x1000, 0x2000, 0, 0, "");
   Elf* invalid_elf = new Elf(nullptr);
   map_info.elf.reset(invalid_elf);
 
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
index a65c077..aab9ec2 100644
--- a/libunwindstack/tests/UnwindOfflineTest.cpp
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -298,7 +298,7 @@
   EXPECT_EQ(
       "  #00 pc 00068fb8  libarttestd.so (_ZN3artL13CauseSegfaultEv+72)\n"
       "  #01 pc 00067f00  libarttestd.so (Java_Main_unwindInProcess+10032)\n"
-      "  #02 pc 000021a8 (offset 0x2000)  137-cfi.odex (boolean Main.unwindInProcess(boolean, int, "
+      "  #02 pc 000021a8  137-cfi.odex (offset 0x2000) (boolean Main.unwindInProcess(boolean, int, "
       "boolean)+136)\n"
       "  #03 pc 0000fe80  anonymous:ee74c000 (boolean Main.bar(boolean)+64)\n"
       "  #04 pc 006ad4d2  libartd.so (art_quick_invoke_stub+338)\n"
@@ -591,7 +591,7 @@
   ASSERT_EQ(76U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
   EXPECT_EQ(
       "  #00 pc 00018a5e  libarttestd.so (Java_Main_unwindInProcess+866)\n"
-      "  #01 pc 0000212d (offset 0x2000)  137-cfi.odex (boolean Main.unwindInProcess(boolean, int, "
+      "  #01 pc 0000212d  137-cfi.odex (offset 0x2000) (boolean Main.unwindInProcess(boolean, int, "
       "boolean)+92)\n"
       "  #02 pc 00011cb1  anonymous:e2796000 (boolean Main.bar(boolean)+72)\n"
       "  #03 pc 00462175  libartd.so (art_quick_invoke_stub_internal+68)\n"
@@ -1135,29 +1135,29 @@
   std::string frame_info(DumpFrames(unwinder));
   ASSERT_EQ(19U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
   EXPECT_EQ(
-      "  #00 pc 0032bfa0 (offset 0x42000)  libunwindstack_test (SignalInnerFunction+40)\n"
-      "  #01 pc 0032bfeb (offset 0x42000)  libunwindstack_test (SignalMiddleFunction+2)\n"
-      "  #02 pc 0032bff3 (offset 0x42000)  libunwindstack_test (SignalOuterFunction+2)\n"
-      "  #03 pc 0032fed3 (offset 0x42000)  libunwindstack_test "
+      "  #00 pc 0032bfa0  libunwindstack_test (SignalInnerFunction+40)\n"
+      "  #01 pc 0032bfeb  libunwindstack_test (SignalMiddleFunction+2)\n"
+      "  #02 pc 0032bff3  libunwindstack_test (SignalOuterFunction+2)\n"
+      "  #03 pc 0032fed3  libunwindstack_test "
       "(_ZN11unwindstackL19SignalCallerHandlerEiP7siginfoPv+26)\n"
-      "  #04 pc 00026528 (offset 0x25000)  libc.so\n"
+      "  #04 pc 00026528  libc.so\n"
       "  #05 pc 00000000  <unknown>\n"
-      "  #06 pc 0032c2d9 (offset 0x42000)  libunwindstack_test (InnerFunction+736)\n"
-      "  #07 pc 0032cc4f (offset 0x42000)  libunwindstack_test (MiddleFunction+42)\n"
-      "  #08 pc 0032cc81 (offset 0x42000)  libunwindstack_test (OuterFunction+42)\n"
-      "  #09 pc 0032e547 (offset 0x42000)  libunwindstack_test "
+      "  #06 pc 0032c2d9  libunwindstack_test (InnerFunction+736)\n"
+      "  #07 pc 0032cc4f  libunwindstack_test (MiddleFunction+42)\n"
+      "  #08 pc 0032cc81  libunwindstack_test (OuterFunction+42)\n"
+      "  #09 pc 0032e547  libunwindstack_test "
       "(_ZN11unwindstackL19RemoteThroughSignalEij+270)\n"
-      "  #10 pc 0032ed99 (offset 0x42000)  libunwindstack_test "
+      "  #10 pc 0032ed99  libunwindstack_test "
       "(_ZN11unwindstack55UnwindTest_remote_through_signal_with_invalid_func_Test8TestBodyEv+16)\n"
-      "  #11 pc 00354453 (offset 0x42000)  libunwindstack_test (_ZN7testing4Test3RunEv+154)\n"
-      "  #12 pc 00354de7 (offset 0x42000)  libunwindstack_test (_ZN7testing8TestInfo3RunEv+194)\n"
-      "  #13 pc 00355105 (offset 0x42000)  libunwindstack_test (_ZN7testing8TestCase3RunEv+180)\n"
-      "  #14 pc 0035a215 (offset 0x42000)  libunwindstack_test "
+      "  #11 pc 00354453  libunwindstack_test (_ZN7testing4Test3RunEv+154)\n"
+      "  #12 pc 00354de7  libunwindstack_test (_ZN7testing8TestInfo3RunEv+194)\n"
+      "  #13 pc 00355105  libunwindstack_test (_ZN7testing8TestCase3RunEv+180)\n"
+      "  #14 pc 0035a215  libunwindstack_test "
       "(_ZN7testing8internal12UnitTestImpl11RunAllTestsEv+664)\n"
-      "  #15 pc 00359f4f (offset 0x42000)  libunwindstack_test (_ZN7testing8UnitTest3RunEv+110)\n"
-      "  #16 pc 0034d3db (offset 0x42000)  libunwindstack_test (main+38)\n"
-      "  #17 pc 00092c0d (offset 0x25000)  libc.so (__libc_init+48)\n"
-      "  #18 pc 0004202f (offset 0x42000)  libunwindstack_test (_start_main+38)\n",
+      "  #15 pc 00359f4f  libunwindstack_test (_ZN7testing8UnitTest3RunEv+110)\n"
+      "  #16 pc 0034d3db  libunwindstack_test (main+38)\n"
+      "  #17 pc 00092c0d  libc.so (__libc_init+48)\n"
+      "  #18 pc 0004202f  libunwindstack_test (_start_main+38)\n",
       frame_info);
 
   EXPECT_EQ(0x2e55fa0U, unwinder.frames()[0].pc);
@@ -1239,4 +1239,79 @@
   EXPECT_EQ(0xffd4a718U, unwinder.frames()[7].sp);
 }
 
+TEST_F(UnwindOfflineTest, shared_lib_in_apk_arm64) {
+  ASSERT_NO_FATAL_FAILURE(Init("shared_lib_in_apk_arm64/", ARCH_ARM64));
+
+  Unwinder unwinder(128, maps_.get(), regs_.get(), process_memory_);
+  unwinder.Unwind();
+
+  std::string frame_info(DumpFrames(unwinder));
+  ASSERT_EQ(7U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+  EXPECT_EQ(
+      "  #00 pc 000000000014ccbc  linker64 (__dl_syscall+28)\n"
+      "  #01 pc 000000000005426c  linker64 "
+      "(__dl__ZL24debuggerd_signal_handleriP7siginfoPv+1128)\n"
+      "  #02 pc 00000000000008bc  vdso.so\n"
+      "  #03 pc 00000000000846f4  libc.so (abort+172)\n"
+      "  #04 pc 0000000000084ad4  libc.so (__assert2+36)\n"
+      "  #05 pc 000000000003d5b4  ANGLEPrebuilt.apk (offset 0x4000) (ANGLEGetUtilityAPI+56)\n"
+      "  #06 pc 000000000007fe68  libc.so (__libc_init)\n",
+      frame_info);
+
+  EXPECT_EQ(0x7e82c4fcbcULL, unwinder.frames()[0].pc);
+  EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[0].sp);
+  EXPECT_EQ(0x7e82b5726cULL, unwinder.frames()[1].pc);
+  EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[1].sp);
+  EXPECT_EQ(0x7e82b018bcULL, unwinder.frames()[2].pc);
+  EXPECT_EQ(0x7df8ca3da0ULL, unwinder.frames()[2].sp);
+  EXPECT_EQ(0x7e7eecc6f4ULL, unwinder.frames()[3].pc);
+  EXPECT_EQ(0x7dabf3db60ULL, unwinder.frames()[3].sp);
+  EXPECT_EQ(0x7e7eeccad4ULL, unwinder.frames()[4].pc);
+  EXPECT_EQ(0x7dabf3dc40ULL, unwinder.frames()[4].sp);
+  EXPECT_EQ(0x7dabc405b4ULL, unwinder.frames()[5].pc);
+  EXPECT_EQ(0x7dabf3dc50ULL, unwinder.frames()[5].sp);
+  EXPECT_EQ(0x7e7eec7e68ULL, unwinder.frames()[6].pc);
+  EXPECT_EQ(0x7dabf3dc70ULL, unwinder.frames()[6].sp);
+  // Ignore top frame since the test code was modified to end in __libc_init.
+}
+
+TEST_F(UnwindOfflineTest, shared_lib_in_apk_memory_only_arm64) {
+  ASSERT_NO_FATAL_FAILURE(Init("shared_lib_in_apk_memory_only_arm64/", ARCH_ARM64));
+  // Add the memory that represents the shared library.
+  MemoryOfflineParts* memory = reinterpret_cast<MemoryOfflineParts*>(process_memory_.get());
+  AddMemory(dir_ + "lib_mem.data", memory);
+
+  Unwinder unwinder(128, maps_.get(), regs_.get(), process_memory_);
+  unwinder.Unwind();
+
+  std::string frame_info(DumpFrames(unwinder));
+  ASSERT_EQ(7U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+  EXPECT_EQ(
+      "  #00 pc 000000000014ccbc  linker64 (__dl_syscall+28)\n"
+      "  #01 pc 000000000005426c  linker64 "
+      "(__dl__ZL24debuggerd_signal_handleriP7siginfoPv+1128)\n"
+      "  #02 pc 00000000000008bc  vdso.so\n"
+      "  #03 pc 00000000000846f4  libc.so (abort+172)\n"
+      "  #04 pc 0000000000084ad4  libc.so (__assert2+36)\n"
+      "  #05 pc 000000000003d5b4  ANGLEPrebuilt.apk (offset 0x21d5000)\n"
+      "  #06 pc 000000000007fe68  libc.so (__libc_init)\n",
+      frame_info);
+
+  EXPECT_EQ(0x7e82c4fcbcULL, unwinder.frames()[0].pc);
+  EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[0].sp);
+  EXPECT_EQ(0x7e82b5726cULL, unwinder.frames()[1].pc);
+  EXPECT_EQ(0x7df8ca3bf0ULL, unwinder.frames()[1].sp);
+  EXPECT_EQ(0x7e82b018bcULL, unwinder.frames()[2].pc);
+  EXPECT_EQ(0x7df8ca3da0ULL, unwinder.frames()[2].sp);
+  EXPECT_EQ(0x7e7eecc6f4ULL, unwinder.frames()[3].pc);
+  EXPECT_EQ(0x7dabf3db60ULL, unwinder.frames()[3].sp);
+  EXPECT_EQ(0x7e7eeccad4ULL, unwinder.frames()[4].pc);
+  EXPECT_EQ(0x7dabf3dc40ULL, unwinder.frames()[4].sp);
+  EXPECT_EQ(0x7dabc405b4ULL, unwinder.frames()[5].pc);
+  EXPECT_EQ(0x7dabf3dc50ULL, unwinder.frames()[5].sp);
+  EXPECT_EQ(0x7e7eec7e68ULL, unwinder.frames()[6].pc);
+  EXPECT_EQ(0x7dabf3dc70ULL, unwinder.frames()[6].sp);
+  // Ignore top frame since the test code was modified to end in __libc_init.
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/UnwinderTest.cpp b/libunwindstack/tests/UnwinderTest.cpp
index 831d3b5..1fdeee5 100644
--- a/libunwindstack/tests/UnwinderTest.cpp
+++ b/libunwindstack/tests/UnwinderTest.cpp
@@ -42,84 +42,64 @@
 
 namespace unwindstack {
 
-class MapsFake : public Maps {
- public:
-  MapsFake() = default;
-  virtual ~MapsFake() = default;
-
-  bool Parse() { return true; }
-
-  void FakeClear() { maps_.clear(); }
-
-  void FakeAddMapInfo(MapInfo* map_info) { maps_.push_back(map_info); }
-};
-
 class UnwinderTest : public ::testing::Test {
  protected:
+  static void AddMapInfo(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+                         const char* name, Elf* elf = nullptr) {
+    std::string str_name(name);
+    maps_->Add(start, end, offset, flags, name, static_cast<uint64_t>(-1));
+    if (elf != nullptr) {
+      MapInfo* map_info = *--maps_->end();
+      map_info->elf.reset(elf);
+    }
+  }
+
   static void SetUpTestCase() {
-    maps_.FakeClear();
-    MapInfo* info =
-        new MapInfo(&maps_, 0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so");
+    maps_.reset(new Maps);
+
     ElfFake* elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so", elf);
 
-    info = new MapInfo(&maps_, 0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
 
-    info = new MapInfo(&maps_, 0x13000, 0x15000, 0, PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP,
-                       "/dev/fake_device");
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x13000, 0x15000, 0, PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP,
+               "/dev/fake_device");
 
-    info = new MapInfo(&maps_, 0x20000, 0x22000, 0, PROT_READ | PROT_WRITE,
-                       "/system/fake/libunwind.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x20000, 0x22000, 0, PROT_READ | PROT_WRITE, "/system/fake/libunwind.so", elf);
 
-    info = new MapInfo(&maps_, 0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so", elf);
 
-    info = new MapInfo(&maps_, 0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so", elf);
 
-    info = new MapInfo(&maps_, 0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk", elf);
 
-    info = new MapInfo(&maps_, 0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
 
-    info = new MapInfo(&maps_, 0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
-                       "/fake/fake.vdex");
+    AddMapInfo(0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake.vdex");
+    MapInfo* info = *--maps_->end();
     info->load_bias = 0;
-    maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(&maps_, 0xa5000, 0xa6000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
-                       "/fake/fake_load_bias.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     elf->FakeSetLoadBias(0x5000);
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0xa5000, 0xa6000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake_load_bias.so",
+               elf);
 
-    info = new MapInfo(&maps_, 0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
-                       "/fake/fake_offset.oat");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
+    AddMapInfo(0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake_offset.oat",
+               elf);
+    info = *--maps_->end();
     info->elf_offset = 0x8000;
-    maps_.FakeAddMapInfo(info);
 
     process_memory_.reset(new MemoryFake);
   }
@@ -130,12 +110,12 @@
     regs_.FakeSetReturnAddressValid(false);
   }
 
-  static MapsFake maps_;
+  static std::unique_ptr<Maps> maps_;
   static RegsFake regs_;
   static std::shared_ptr<Memory> process_memory_;
 };
 
-MapsFake UnwinderTest::maps_;
+std::unique_ptr<Maps> UnwinderTest::maps_;
 RegsFake UnwinderTest::regs_(5);
 std::shared_ptr<Memory> UnwinderTest::process_memory_(nullptr);
 
@@ -150,7 +130,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x1202, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -164,7 +144,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -178,7 +159,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -192,7 +174,8 @@
   EXPECT_EQ("Frame2", frame->function_name);
   EXPECT_EQ(2U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -210,7 +193,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x1202, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.SetResolveNames(false);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
@@ -225,7 +208,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -239,7 +223,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -253,7 +238,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -267,7 +253,7 @@
   regs_.set_sp(0x10000);
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -281,7 +267,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake_load_bias.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa5000U, frame->map_start);
   EXPECT_EQ(0xa6000U, frame->map_end);
   EXPECT_EQ(0x5000U, frame->map_load_bias);
@@ -295,7 +282,7 @@
   regs_.set_sp(0x10000);
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -309,7 +296,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake_offset.oat", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa7000U, frame->map_start);
   EXPECT_EQ(0xa8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -323,7 +311,7 @@
   regs_.set_sp(0x10000);
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -337,7 +325,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.apk", frame->map_name);
-  EXPECT_EQ(0x1d000U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0x1d000U, frame->map_exact_offset);
   EXPECT_EQ(0x43000U, frame->map_start);
   EXPECT_EQ(0x44000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -358,7 +347,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x1102, 0x10010, false));
   ElfInterfaceFake::FakePushStepData(StepData(0x1202, 0x10020, false));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -372,7 +361,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -389,7 +379,7 @@
   regs_.set_pc(0x1000);
   regs_.set_sp(0x10000);
 
-  Unwinder unwinder(20, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(20, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_MAX_FRAMES_EXCEEDED, unwinder.LastErrorCode());
 
@@ -404,7 +394,8 @@
     EXPECT_EQ("Frame" + std::to_string(i), frame->function_name) << "Failed at frame " << i;
     EXPECT_EQ(i, frame->function_offset) << "Failed at frame " << i;
     EXPECT_EQ("/system/fake/libc.so", frame->map_name) << "Failed at frame " << i;
-    EXPECT_EQ(0U, frame->map_offset) << "Failed at frame " << i;
+    EXPECT_EQ(0U, frame->map_elf_start_offset) << "Failed at frame " << i;
+    EXPECT_EQ(0U, frame->map_exact_offset) << "Failed at frame " << i;
     EXPECT_EQ(0x1000U, frame->map_start) << "Failed at frame " << i;
     EXPECT_EQ(0x8000U, frame->map_end) << "Failed at frame " << i;
     EXPECT_EQ(0U, frame->map_load_bias) << "Failed at frame " << i;
@@ -429,7 +420,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23002, 0x10070, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   std::vector<std::string> skip_libs{"libunwind.so", "libanother.so"};
   unwinder.Unwind(&skip_libs);
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
@@ -444,7 +435,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -458,7 +450,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x20000U, frame->map_start);
   EXPECT_EQ(0x22000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -472,7 +465,7 @@
   EXPECT_EQ("Frame2", frame->function_name);
   EXPECT_EQ(2U, frame->function_offset);
   EXPECT_EQ("/fake/libanother.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x23000U, frame->map_start);
   EXPECT_EQ(0x24000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -489,7 +482,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x21002, 0x50020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -503,7 +496,7 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -517,7 +510,7 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x20000U, frame->map_start);
   EXPECT_EQ(0x22000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -536,7 +529,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23102, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -555,7 +548,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23102, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -569,7 +562,7 @@
   regs_.set_pc(0x41000);
   regs_.set_sp(0x13000);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());
 
@@ -583,7 +576,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -604,7 +598,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23102, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -618,7 +612,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -632,7 +627,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -646,7 +642,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/libanother.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x23000U, frame->map_start);
   EXPECT_EQ(0x24000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -660,16 +657,66 @@
   ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame1", 1));
 
   // Fake as if code called a nullptr function.
+  regs_.set_pc(0x20000);
+  regs_.set_sp(0x10000);
+  ElfInterfaceFake::FakePushStepData(StepData(0, 0x10010, false));
+  regs_.FakeSetReturnAddress(0x12);
+  regs_.FakeSetReturnAddressValid(true);
+
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
+  unwinder.Unwind();
+  EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());
+
+  ASSERT_EQ(2U, unwinder.NumFrames());
+
+  auto* frame = &unwinder.frames()[0];
+  EXPECT_EQ(0U, frame->num);
+  EXPECT_EQ(0U, frame->rel_pc);
+  EXPECT_EQ(0x20000U, frame->pc);
+  EXPECT_EQ(0x10000U, frame->sp);
+  EXPECT_EQ("Frame0", frame->function_name);
+  EXPECT_EQ(0U, frame->function_offset);
+  EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
+  EXPECT_EQ(0x20000U, frame->map_start);
+  EXPECT_EQ(0x22000U, frame->map_end);
+  EXPECT_EQ(0U, frame->map_load_bias);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, frame->map_flags);
+
+  frame = &unwinder.frames()[1];
+  EXPECT_EQ(1U, frame->num);
+  EXPECT_EQ(0U, frame->rel_pc);
+  EXPECT_EQ(0U, frame->pc);
+  EXPECT_EQ(0x10010U, frame->sp);
+  EXPECT_EQ("", frame->function_name);
+  EXPECT_EQ(0U, frame->function_offset);
+  EXPECT_EQ("", frame->map_name);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
+  EXPECT_EQ(0U, frame->map_start);
+  EXPECT_EQ(0U, frame->map_end);
+  EXPECT_EQ(0U, frame->map_load_bias);
+  EXPECT_EQ(0, frame->map_flags);
+}
+
+// Verify that a speculative frame is added and left if there are only
+// two frames and the pc is in the middle nowhere.
+TEST_F(UnwinderTest, speculative_frame_not_removed_pc_bad) {
+  ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 0));
+  ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame1", 1));
+
+  // Fake as if code called a nullptr function.
   regs_.set_pc(0);
   regs_.set_sp(0x10000);
   regs_.FakeSetReturnAddress(0x1202);
   regs_.FakeSetReturnAddressValid(true);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
-  ASSERT_EQ(1U, unwinder.NumFrames());
+  ASSERT_EQ(2U, unwinder.NumFrames());
 
   auto* frame = &unwinder.frames()[0];
   EXPECT_EQ(0U, frame->num);
@@ -679,11 +726,27 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
   EXPECT_EQ(0, frame->map_flags);
+
+  frame = &unwinder.frames()[1];
+  EXPECT_EQ(1U, frame->num);
+  EXPECT_EQ(0x200U, frame->rel_pc);
+  EXPECT_EQ(0x1200U, frame->pc);
+  EXPECT_EQ(0x10000U, frame->sp);
+  EXPECT_EQ("Frame0", frame->function_name);
+  EXPECT_EQ(0U, frame->function_offset);
+  EXPECT_EQ("/system/fake/libc.so", frame->map_name);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
+  EXPECT_EQ(0x1000U, frame->map_start);
+  EXPECT_EQ(0x8000U, frame->map_end);
+  EXPECT_EQ(0U, frame->map_load_bias);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, frame->map_flags);
 }
 
 // Verify that an unwind stops when a frame is in given suffix.
@@ -700,14 +763,14 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x53502, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   std::vector<std::string> suffixes{"oat"};
   unwinder.Unwind(nullptr, &suffixes);
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
   // Make sure the elf was not initialized.
-  MapInfo* map_info = maps_.Find(0x53000);
+  MapInfo* map_info = maps_->Find(0x53000);
   ASSERT_TRUE(map_info != nullptr);
   EXPECT_TRUE(map_info->elf == nullptr);
 
@@ -719,7 +782,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -733,7 +797,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/fake.apk", frame->map_name);
-  EXPECT_EQ(0x1d000U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0x1d000U, frame->map_exact_offset);
   EXPECT_EQ(0x43000U, frame->map_start);
   EXPECT_EQ(0x44000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -757,7 +822,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x33502, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_REPEATED_FRAME, unwinder.LastErrorCode());
 
@@ -771,7 +836,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -785,7 +851,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/compressed.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x33000U, frame->map_start);
   EXPECT_EQ(0x34000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -799,7 +866,8 @@
   EXPECT_EQ("Frame2", frame->function_name);
   EXPECT_EQ(2U, frame->function_offset);
   EXPECT_EQ("/fake/compressed.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x33000U, frame->map_start);
   EXPECT_EQ(0x34000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -812,7 +880,7 @@
   regs_.set_sp(0x10000);
   regs_.FakeSetDexPc(0xa3400);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -826,7 +894,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.vdex", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa3000U, frame->map_start);
   EXPECT_EQ(0xa4000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -840,7 +909,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -853,7 +923,7 @@
   regs_.set_sp(0x10000);
   regs_.FakeSetDexPc(0x50000);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -867,7 +937,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -881,7 +952,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -897,7 +969,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x33402, 0x10010, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -911,7 +983,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.vdex", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa3000U, frame->map_start);
   EXPECT_EQ(0xa4000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -925,7 +998,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -939,7 +1013,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/compressed.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x33000U, frame->map_start);
   EXPECT_EQ(0x34000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -952,7 +1027,7 @@
   regs_.set_sp(0x10000);
   regs_.FakeSetDexPc(0xa3400);
 
-  Unwinder unwinder(1, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(1, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_MAX_FRAMES_EXCEEDED, unwinder.LastErrorCode());
 
@@ -966,7 +1041,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.vdex", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa3000U, frame->map_start);
   EXPECT_EQ(0xa4000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -983,17 +1059,17 @@
   frame.function_name = "function";
   frame.function_offset = 100;
   frame.map_name = "/fake/libfake.so";
-  frame.map_offset = 0x2000;
+  frame.map_elf_start_offset = 0x2000;
   frame.map_start = 0x3000;
   frame.map_end = 0x6000;
   frame.map_flags = PROT_READ;
 
-  EXPECT_EQ("  #01 pc 0000000000001000 (offset 0x2000)  /fake/libfake.so (function+100)",
+  EXPECT_EQ("  #01 pc 0000000000001000  /fake/libfake.so (offset 0x2000) (function+100)",
             Unwinder::FormatFrame(frame, false));
-  EXPECT_EQ("  #01 pc 00001000 (offset 0x2000)  /fake/libfake.so (function+100)",
+  EXPECT_EQ("  #01 pc 00001000  /fake/libfake.so (offset 0x2000) (function+100)",
             Unwinder::FormatFrame(frame, true));
 
-  frame.map_offset = 0;
+  frame.map_elf_start_offset = 0;
   EXPECT_EQ("  #01 pc 0000000000001000  /fake/libfake.so (function+100)",
             Unwinder::FormatFrame(frame, false));
   EXPECT_EQ("  #01 pc 00001000  /fake/libfake.so (function+100)",
@@ -1068,7 +1144,7 @@
   for (auto regs : reg_list) {
     ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 10));
 
-    Unwinder unwinder(64, &maps_, regs, process_memory_);
+    Unwinder unwinder(64, maps_.get(), regs, process_memory_);
     unwinder.Unwind();
 
     ASSERT_EQ(1U, unwinder.NumFrames());
diff --git a/libunwindstack/tests/files/offline/offset_arm/maps.txt b/libunwindstack/tests/files/offline/offset_arm/maps.txt
index 6224464..768dd9f 100644
--- a/libunwindstack/tests/files/offline/offset_arm/maps.txt
+++ b/libunwindstack/tests/files/offline/offset_arm/maps.txt
@@ -1,2 +1,4 @@
+2b2a000-2b6c000 r--p 0 00:00 0   libunwindstack_test
 2b6c000-2e92000 r-xp 42000 00:00 0   libunwindstack_test
+f4110000-f4135000 r--p 0 00:00 0   libc.so
 f4135000-f41a9000 r-xp 25000 00:00 0   libc.so
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/ANGLEPrebuilt.apk b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/ANGLEPrebuilt.apk
new file mode 100644
index 0000000..0277359
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/ANGLEPrebuilt.apk
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/libc.so b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/libc.so
new file mode 100644
index 0000000..20008fd
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/libc.so
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/linker64 b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/linker64
new file mode 100644
index 0000000..b90933b
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/linker64
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/maps.txt b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/maps.txt
new file mode 100644
index 0000000..c4fc067
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/maps.txt
@@ -0,0 +1,7 @@
+7dabc03000-7dabc3f000 r--p 4000 00:00 0   ANGLEPrebuilt.apk
+7dabc3f000-7dabcf0000 r-xp 40000 00:00 0   ANGLEPrebuilt.apk
+7e7ee48000-7e7ee88000 r--p 0 00:00 0   libc.so
+7e7ee88000-7e7ef32000 r-xp 40000 00:00 0   libc.so
+7e82b01000-7e82b03000 r-xp 0 00:00 0   vdso.so
+7e82b03000-7e82b3c000 r--p 0 00:00 0   linker64
+7e82b3c000-7e82c77000 r-xp 39000 00:00 0   linker64
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/regs.txt b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/regs.txt
new file mode 100644
index 0000000..1e2ea32
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/regs.txt
@@ -0,0 +1,33 @@
+x0: 7df8ca3c24
+x1: 0
+x2: ffffffff
+x3: 0
+x4: 0
+x5: 0
+x6: 0
+x7: 7f7f7f7f7f7f7f7f
+x8: 62
+x9: 20dd5829922a93ac
+x10: 7e82b57420
+x11: 4100
+x12: 7df8ca3b70
+x13: 7df8ca3b98
+x14: 73d015e5
+x15: 39a36122467299
+x16: 76ac
+x17: 0
+x18: 7df8cfc000
+x19: 7dabf3e7a0
+x20: 7df8ca3da0
+x21: 59616d61
+x22: 1
+x23: 7df8ca3c24
+x24: 1894
+x25: 62
+x26: 2
+x27: 0
+x28: 7dabf3e790
+x29: 7df8ca3d90
+sp: 7df8ca3bf0
+lr: 7e82b57270
+pc: 7e82c4fcbc
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/stack0.data b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/stack0.data
new file mode 100644
index 0000000..ec07e15
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/stack0.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/stack1.data b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/stack1.data
new file mode 100644
index 0000000..825bb1a
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/stack1.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/vdso.so b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/vdso.so
new file mode 100644
index 0000000..205ebd4
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_arm64/vdso.so
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/lib_mem.data b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/lib_mem.data
new file mode 100644
index 0000000..f39d127
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/lib_mem.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/libc.so b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/libc.so
new file mode 100644
index 0000000..20008fd
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/libc.so
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/linker64 b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/linker64
new file mode 100644
index 0000000..b90933b
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/linker64
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/maps.txt b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/maps.txt
new file mode 100644
index 0000000..386d57a
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/maps.txt
@@ -0,0 +1,7 @@
+7dabc03000-7dabc3f000 r--p 21d5000 00:00 0   ANGLEPrebuilt.apk
+7dabc3f000-7dabcf0000 r-xp 2211000 00:00 0   ANGLEPrebuilt.apk
+7e7ee48000-7e7ee88000 r--p 0 00:00 0   libc.so
+7e7ee88000-7e7ef32000 r-xp 40000 00:00 0   libc.so
+7e82b01000-7e82b03000 r-xp 0 00:00 0   vdso.so
+7e82b03000-7e82b3c000 r--p 0 00:00 0   linker64
+7e82b3c000-7e82c77000 r-xp 39000 00:00 0   linker64
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/regs.txt b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/regs.txt
new file mode 100644
index 0000000..1e2ea32
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/regs.txt
@@ -0,0 +1,33 @@
+x0: 7df8ca3c24
+x1: 0
+x2: ffffffff
+x3: 0
+x4: 0
+x5: 0
+x6: 0
+x7: 7f7f7f7f7f7f7f7f
+x8: 62
+x9: 20dd5829922a93ac
+x10: 7e82b57420
+x11: 4100
+x12: 7df8ca3b70
+x13: 7df8ca3b98
+x14: 73d015e5
+x15: 39a36122467299
+x16: 76ac
+x17: 0
+x18: 7df8cfc000
+x19: 7dabf3e7a0
+x20: 7df8ca3da0
+x21: 59616d61
+x22: 1
+x23: 7df8ca3c24
+x24: 1894
+x25: 62
+x26: 2
+x27: 0
+x28: 7dabf3e790
+x29: 7df8ca3d90
+sp: 7df8ca3bf0
+lr: 7e82b57270
+pc: 7e82c4fcbc
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/stack0.data b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/stack0.data
new file mode 100644
index 0000000..ec07e15
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/stack0.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/stack1.data b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/stack1.data
new file mode 100644
index 0000000..825bb1a
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/stack1.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/vdso.so b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/vdso.so
new file mode 100644
index 0000000..205ebd4
--- /dev/null
+++ b/libunwindstack/tests/files/offline/shared_lib_in_apk_memory_only_arm64/vdso.so
Binary files differ
diff --git a/libunwindstack/tools/unwind.cpp b/libunwindstack/tools/unwind.cpp
index 22ca7bf..e729453 100644
--- a/libunwindstack/tools/unwind.cpp
+++ b/libunwindstack/tools/unwind.cpp
@@ -35,7 +35,12 @@
 #include <unwindstack/Unwinder.h>
 
 static bool Attach(pid_t pid) {
-  if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
+  if (ptrace(PTRACE_SEIZE, pid, 0, 0) == -1) {
+    return false;
+  }
+
+  if (ptrace(PTRACE_INTERRUPT, pid, 0, 0) == -1) {
+    ptrace(PTRACE_DETACH, pid, 0, 0);
     return false;
   }
 
diff --git a/libunwindstack/tools/unwind_for_offline.cpp b/libunwindstack/tools/unwind_for_offline.cpp
index 640992f..5ae8874 100644
--- a/libunwindstack/tools/unwind_for_offline.cpp
+++ b/libunwindstack/tools/unwind_for_offline.cpp
@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <sys/ptrace.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -46,11 +47,17 @@
   uint64_t start;
   uint64_t end;
   uint64_t offset;
+  uint64_t flags;
   std::string name;
 };
 
 static bool Attach(pid_t pid) {
-  if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
+  if (ptrace(PTRACE_SEIZE, pid, 0, 0) == -1) {
+    return false;
+  }
+
+  if (ptrace(PTRACE_INTERRUPT, pid, 0, 0) == -1) {
+    ptrace(PTRACE_DETACH, pid, 0, 0);
     return false;
   }
 
@@ -158,14 +165,19 @@
   return true;
 }
 
-bool CopyElfFromFile(map_info_t* info) {
+bool CopyElfFromFile(map_info_t* info, bool* file_copied) {
+  std::string cur_name = basename(info->name.c_str());
+  if (*file_copied) {
+    info->name = cur_name;
+    return true;
+  }
+
   std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(info->name.c_str(), "r"), &fclose);
   if (fp == nullptr) {
     perror((std::string("Cannot open ") + info->name).c_str());
     return false;
   }
 
-  std::string cur_name = basename(info->name.c_str());
   std::unique_ptr<FILE, decltype(&fclose)> output(fopen(cur_name.c_str(), "w+"), &fclose);
   if (output == nullptr) {
     perror((std::string("Cannot create file " + cur_name)).c_str());
@@ -188,6 +200,39 @@
   return true;
 }
 
+map_info_t* FillInAndGetMapInfo(std::unordered_map<uint64_t, map_info_t>& maps_by_start,
+                                unwindstack::MapInfo* map_info) {
+  auto info = &maps_by_start[map_info->start];
+  info->start = map_info->start;
+  info->end = map_info->end;
+  info->offset = map_info->offset;
+  info->name = map_info->name;
+  info->flags = map_info->flags;
+
+  return info;
+}
+
+void SaveMapInformation(std::shared_ptr<unwindstack::Memory>& process_memory, map_info_t* info,
+                        bool* file_copied) {
+  if (CopyElfFromFile(info, file_copied)) {
+    return;
+  }
+  *file_copied = false;
+
+  // Try to create the elf from memory, this will handle cases where
+  // the data only exists in memory such as vdso data on x86.
+  if (CreateElfFromMemory(process_memory, info)) {
+    return;
+  }
+
+  printf("Cannot save memory or file for map ");
+  if (!info->name.empty()) {
+    printf("%s\n", info->name.c_str());
+  } else {
+    printf("anonymous:%" PRIx64 "\n", info->start);
+  }
+}
+
 int SaveData(pid_t pid) {
   unwindstack::Regs* regs = unwindstack::Regs::RemoteGet(pid);
   if (regs == nullptr) {
@@ -224,7 +269,7 @@
     sp_map_start = map_info->start;
   }
 
-  for (auto frame : unwinder.frames()) {
+  for (const auto& frame : unwinder.frames()) {
     map_info = maps.Find(frame.sp);
     if (map_info != nullptr && sp_map_start != map_info->start) {
       stacks.emplace_back(std::make_pair(frame.sp, map_info->end));
@@ -232,22 +277,21 @@
     }
 
     if (maps_by_start.count(frame.map_start) == 0) {
-      auto info = &maps_by_start[frame.map_start];
-      info->start = frame.map_start;
-      info->end = frame.map_end;
-      info->offset = frame.map_offset;
-      info->name = frame.map_name;
-      if (!CopyElfFromFile(info)) {
-        // Try to create the elf from memory, this will handle cases where
-        // the data only exists in memory such as vdso data on x86.
-        if (!CreateElfFromMemory(process_memory, info)) {
-          printf("Ignoring map ");
-          if (!info->name.empty()) {
-            printf("%s\n", info->name.c_str());
-          } else {
-            printf("anonymous:%" PRIx64 "\n", info->start);
-          }
-        }
+      map_info = maps.Find(frame.map_start);
+
+      auto info = FillInAndGetMapInfo(maps_by_start, map_info);
+      bool file_copied = false;
+      SaveMapInformation(process_memory, info, &file_copied);
+
+      // If you are using a a linker that creates two maps (one read-only, one
+      // read-executable), it's necessary to capture the previous map
+      // information if needed.
+      unwindstack::MapInfo* prev_map = map_info->prev_map;
+      if (prev_map != nullptr && map_info->offset != 0 && prev_map->offset == 0 &&
+          prev_map->flags == PROT_READ && map_info->name == prev_map->name &&
+          maps_by_start.count(prev_map->start) == 0) {
+        info = FillInAndGetMapInfo(maps_by_start, prev_map);
+        SaveMapInformation(process_memory, info, &file_copied);
       }
     }
   }
@@ -272,8 +316,18 @@
   }
 
   for (auto& element : sorted_maps) {
+    char perms[5] = {"---p"};
     map_info_t& map = element.second;
-    fprintf(fp.get(), "%" PRIx64 "-%" PRIx64 " r-xp %" PRIx64 " 00:00 0", map.start, map.end,
+    if (map.flags & PROT_READ) {
+      perms[0] = 'r';
+    }
+    if (map.flags & PROT_WRITE) {
+      perms[1] = 'w';
+    }
+    if (map.flags & PROT_EXEC) {
+      perms[2] = 'x';
+    }
+    fprintf(fp.get(), "%" PRIx64 "-%" PRIx64 " %s %" PRIx64 " 00:00 0", map.start, map.end, perms,
             map.offset);
     if (!map.name.empty()) {
       fprintf(fp.get(), "   %s", map.name.c_str());
diff --git a/libutils/Looper.cpp b/libutils/Looper.cpp
index 102fdf0..b3f943d 100644
--- a/libutils/Looper.cpp
+++ b/libutils/Looper.cpp
@@ -51,9 +51,6 @@
 
 // --- Looper ---
 
-// Hint for number of file descriptors to be associated with the epoll instance.
-static const int EPOLL_SIZE_HINT = 8;
-
 // Maximum number of file descriptors for which to retrieve poll events each iteration.
 static const int EPOLL_MAX_EVENTS = 16;
 
@@ -139,7 +136,7 @@
     }
 
     // Allocate the new epoll instance and register the wake pipe.
-    mEpollFd.reset(epoll_create(EPOLL_SIZE_HINT));
+    mEpollFd.reset(epoll_create1(EPOLL_CLOEXEC));
     LOG_ALWAYS_FATAL_IF(mEpollFd < 0, "Could not create epoll instance: %s", strerror(errno));
 
     struct epoll_event eventItem;
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index 9eb7f2c..6b9f6e1 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -491,7 +491,7 @@
 }
 
 int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle) {
-  const int fd = ::android::base::utf8::open(fileName, O_RDONLY | O_BINARY, 0);
+  const int fd = ::android::base::utf8::open(fileName, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
   ZipArchive* archive = new ZipArchive(fd, true);
   *handle = archive;
 
diff --git a/llkd/README.md b/llkd/README.md
index 3da7a2f..224e184 100644
--- a/llkd/README.md
+++ b/llkd/README.md
@@ -160,7 +160,7 @@
 NB: false is a very very very unlikely process to want to blacklist.
 
 #### ro.llk.blacklist.parent
-default 0,2 (kernel and [kthreadd]).
+default 0,2,adbd (kernel, [kthreadd] and adbd).
 The string "*false*" is the equivalent to an *empty* list.
 Do not watch processes that have this parent.
 A parent process can be comm, cmdline or pid reference.
diff --git a/llkd/include/llkd.h b/llkd/include/llkd.h
index b16b1d8..1efa32b 100644
--- a/llkd/include/llkd.h
+++ b/llkd/include/llkd.h
@@ -55,7 +55,11 @@
 #define LLK_BLACKLIST_PROCESS_DEFAULT  \
     "0,1,2,init,[kthreadd],[khungtaskd],lmkd,llkd,watchdogd,[watchdogd],[watchdogd/0]"
 #define LLK_BLACKLIST_PARENT_PROPERTY  "ro.llk.blacklist.parent"
+#ifdef __PTRACE_ENABLED__  // defined if userdebug build
+#define LLK_BLACKLIST_PARENT_DEFAULT   "0,2,[kthreadd],adbd"
+#else
 #define LLK_BLACKLIST_PARENT_DEFAULT   "0,2,[kthreadd]"
+#endif
 #define LLK_BLACKLIST_UID_PROPERTY     "ro.llk.blacklist.uid"
 #define LLK_BLACKLIST_UID_DEFAULT      ""
 #define LLK_BLACKLIST_STACK_PROPERTY   "ro.llk.blacklist.process.stack"
diff --git a/llkd/libllkd.cpp b/llkd/libllkd.cpp
index 427dace..267da4a 100644
--- a/llkd/libllkd.cpp
+++ b/llkd/libllkd.cpp
@@ -510,9 +510,7 @@
     return android::base::Trim(content) == string;
 }
 
-void llkPanicKernel(bool dump, pid_t tid, const char* state,
-                    const std::string& message = "") __noreturn;
-void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message) {
+void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message = "") {
     if (!message.empty()) LOG(ERROR) << message;
     auto sysrqTriggerFd = llkFileToWriteFd("/proc/sysrq-trigger");
     if (sysrqTriggerFd < 0) {
@@ -521,6 +519,7 @@
         // The answer to life, the universe and everything
         ::exit(42);
         // NOTREACHED
+        return;
     }
     ::sync();
     if (dump) {
@@ -544,6 +543,13 @@
     llkWriteStringToFile(message + (message.empty() ? "" : "\n") +
                                  "SysRq : Trigger a crash : 'livelock,"s + state + "'\n",
                          "/dev/kmsg");
+    // Because panic is such a serious thing to do, let us
+    // make sure that the tid being inspected still exists!
+    auto piddir = procdir + std::to_string(tid) + "/stat";
+    if (access(piddir.c_str(), F_OK) != 0) {
+        PLOG(WARNING) << piddir;
+        return;
+    }
     android::base::WriteStringToFd("c", sysrqTriggerFd);
     // NOTREACHED
     // DYB
@@ -610,7 +616,7 @@
 
 std::string llkFormat(const std::unordered_set<std::string>& blacklist) {
     std::string ret;
-    for (auto entry : blacklist) {
+    for (const auto& entry : blacklist) {
         if (ret.size()) {
             ret += ",";
         }
@@ -909,6 +915,7 @@
     ms -= llkCycle;
     auto myPid = ::getpid();
     auto myTid = ::gettid();
+    auto dump = true;
     for (auto dp = llkTopDirectory.read(); dp != nullptr; dp = llkTopDirectory.read()) {
         std::string piddir;
 
@@ -1109,9 +1116,10 @@
             const auto message = state + " "s + llkFormat(procp->count) + " " +
                                  std::to_string(ppid) + "->" + std::to_string(pid) + "->" +
                                  std::to_string(tid) + " " + procp->getComm() + " [panic]";
-            llkPanicKernel(true, tid,
+            llkPanicKernel(dump, tid,
                            (state == 'Z') ? "zombie" : (state == 'D') ? "driver" : "sleeping",
                            message);
+            dump = false;
         }
         LOG(VERBOSE) << "+closedir()";
     }
diff --git a/rootdir/etc/ld.config.txt b/rootdir/etc/ld.config.txt
index d3e80c9..e510c3c 100644
--- a/rootdir/etc/ld.config.txt
+++ b/rootdir/etc/ld.config.txt
@@ -73,6 +73,7 @@
 namespace.default.permitted.paths += /%PRODUCT_SERVICES%/priv-app
 namespace.default.permitted.paths += /data
 namespace.default.permitted.paths += /mnt/expand
+namespace.default.permitted.paths += /apex/com.android.resolv/${LIB}
 
 namespace.default.asan.search.paths  = /data/asan/system/${LIB}
 namespace.default.asan.search.paths +=           /system/${LIB}
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 349168e..483fc51 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -545,6 +545,7 @@
     mkdir /data/anr 0775 system system
 
     mkdir /data/apex 0770 root root
+    mkdir /data/staging 0750 system system
 
     # NFC: create data/nfc for nv storage
     mkdir /data/nfc 0770 nfc nfc
@@ -583,8 +584,8 @@
     # Set SELinux security contexts on upgrade or policy update.
     restorecon --recursive --skip-ce /data
 
-    # Check any timezone data in /data is newer than the copy in /system, delete if not.
-    exec - system system -- /system/bin/tzdatacheck /system/usr/share/zoneinfo /data/misc/zoneinfo
+    # Check any timezone data in /data is newer than the copy in the runtime module, delete if not.
+    exec - system system -- /system/bin/tzdatacheck /apex/com.android.runtime/etc/tz /data/misc/zoneinfo
 
     # If there is no post-fs-data action in the init.<device>.rc file, you
     # must uncomment this line, otherwise encrypted filesystems
diff --git a/rootdir/ueventd.rc b/rootdir/ueventd.rc
index d90a1ce..35f469a 100644
--- a/rootdir/ueventd.rc
+++ b/rootdir/ueventd.rc
@@ -55,6 +55,8 @@
 /dev/v4l-touch*           0660   root       input
 /dev/snd/*                0660   system     audio
 /dev/msm_mp3*             0660   system     audio
+/dev/bus/usb/*            0660   root       usb
+/dev/mtp_usb              0660   root       mtp
 /dev/usb_accessory        0660   root       usb
 /dev/tun                  0660   system     vpn