diff --git a/TEST_MAPPING b/TEST_MAPPING
index c47230f..f9c3b4a 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -2,6 +2,30 @@
   "presubmit": [
     {
       "name": "adbd_test"
+    },
+    {
+      "name": "debuggerd_test"
+    },
+    {
+      "name": "init_tests"
+    },
+    {
+      "name": "libbase_test"
+    },
+    {
+      "name": "libprocinfo_test"
+    },
+    {
+      "name": "memunreachable_test"
+    },
+    {
+      "name": "memunreachable_binder_test"
+    },
+    {
+      "name": "propertyinfoserializer_tests"
+    },
+    {
+      "name": "ziparchive-tests"
     }
   ]
 }
diff --git a/adb/Android.bp b/adb/Android.bp
index 00e98fe..ae8e386 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -25,7 +25,6 @@
         "-Wvla",
     ],
     rtti: true,
-    cpp_std: "gnu++17",
 
     use_version_lib: true,
 
@@ -72,7 +71,7 @@
                 "-DUNICODE=1",
                 "-D_UNICODE=1",
 
-                // -std=gnu++11 doesn't set _GNU_SOURCE on Windows.
+                // Unlike on Linux, -std=gnu++ doesn't set _GNU_SOURCE on Windows.
                 "-D_GNU_SOURCE",
 
                 // MinGW hides some things behind _POSIX_SOURCE.
@@ -285,6 +284,15 @@
         "deploypatchgenerator",
     ],
 
+    // Archive adb, adb.exe.
+    dist: {
+        targets: [
+            "dist_files",
+            "sdk",
+            "win_sdk",
+        ],
+    },
+
     target: {
         darwin: {
             cflags: [
diff --git a/adb/Android.mk b/adb/Android.mk
deleted file mode 100644
index 8b2d558..0000000
--- a/adb/Android.mk
+++ /dev/null
@@ -1,8 +0,0 @@
-LOCAL_PATH := $(call my-dir)
-
-# Archive adb, adb.exe.
-$(call dist-for-goals,dist_files sdk win_sdk,$(HOST_OUT_EXECUTABLES)/adb)
-
-ifdef HOST_CROSS_OS
-$(call dist-for-goals,dist_files sdk win_sdk,$(ALL_MODULES.host_cross_adb.BUILT))
-endif
diff --git a/adb/NOTICE b/adb/NOTICE
index ff47c95..9ffcc08 100644
--- a/adb/NOTICE
+++ b/adb/NOTICE
@@ -189,63 +189,3 @@
 
    END OF TERMS AND CONDITIONS
 
-------------------------------------------------------------
-libwinpthread license:
-------------------------------------------------------------
-Copyright (c) 2011 mingw-w64 project
-
-Permission is hereby granted, free of charge, to any person obtaining a
-copy of this software and associated documentation files (the "Software"),
-to deal in the Software without restriction, including without limitation
-the rights to use, copy, modify, merge, publish, distribute, sublicense,
-and/or sell copies of the Software, and to permit persons to whom the
-Software is furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-DEALINGS IN THE SOFTWARE.
-
-
-/*
- * Parts of this library are derived by:
- *
- * Posix Threads library for Microsoft Windows
- *
- * Use at own risk, there is no implied warranty to this code.
- * It uses undocumented features of Microsoft Windows that can change
- * at any time in the future.
- *
- * (C) 2010 Lockless Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- *
- *  * Redistributions of source code must retain the above copyright notice,
- *    this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *  * Neither the name of Lockless Inc. nor the names of its contributors may be
- *    used to endorse or promote products derived from this software without
- *    specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AN
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
- * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
- * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- */
diff --git a/adb/adb_auth.h b/adb/adb_auth.h
index 715e04f..2fc8478 100644
--- a/adb/adb_auth.h
+++ b/adb/adb_auth.h
@@ -36,6 +36,7 @@
 void adb_auth_init();
 
 int adb_auth_keygen(const char* filename);
+int adb_auth_pubkey(const char* filename);
 std::string adb_auth_get_userkey();
 std::deque<std::shared_ptr<RSA>> adb_auth_get_private_keys();
 
diff --git a/adb/client/adb_install.cpp b/adb/client/adb_install.cpp
index 7f37c45..079a975 100644
--- a/adb/client/adb_install.cpp
+++ b/adb/client/adb_install.cpp
@@ -226,18 +226,8 @@
 
 static int install_app_legacy(int argc, const char** argv, bool use_fastdeploy,
                               bool use_localagent) {
-    static const char* const DATA_DEST = "/data/local/tmp/%s";
-    static const char* const SD_DEST = "/sdcard/tmp/%s";
-    const char* where = DATA_DEST;
-
     printf("Performing Push Install\n");
 
-    for (int i = 1; i < argc; i++) {
-        if (!strcmp(argv[i], "-s")) {
-            where = SD_DEST;
-        }
-    }
-
     // Find last APK argument.
     // All other arguments passed through verbatim.
     int last_apk = -1;
@@ -256,7 +246,7 @@
     int result = -1;
     std::vector<const char*> apk_file = {argv[last_apk]};
     std::string apk_dest =
-            android::base::StringPrintf(where, android::base::Basename(argv[last_apk]).c_str());
+            "/data/local/tmp/" + android::base::Basename(argv[last_apk]);
 
     if (use_fastdeploy == true) {
         TemporaryFile metadataTmpFile;
diff --git a/adb/client/auth.cpp b/adb/client/auth.cpp
index 71c19b8..bcb829b 100644
--- a/adb/client/auth.cpp
+++ b/adb/client/auth.cpp
@@ -43,6 +43,7 @@
 
 #include "adb.h"
 #include "adb_auth.h"
+#include "adb_io.h"
 #include "adb_utils.h"
 #include "sysdeps.h"
 #include "transport.h"
@@ -52,30 +53,7 @@
     *new std::map<std::string, std::shared_ptr<RSA>>;
 static std::map<int, std::string>& g_monitored_paths = *new std::map<int, std::string>;
 
-static std::string get_user_info() {
-    LOG(INFO) << "get_user_info...";
-
-    std::string hostname;
-    if (getenv("HOSTNAME")) hostname = getenv("HOSTNAME");
-#if !defined(_WIN32)
-    char buf[64];
-    if (hostname.empty() && gethostname(buf, sizeof(buf)) != -1) hostname = buf;
-#endif
-    if (hostname.empty()) hostname = "unknown";
-
-    std::string username;
-    if (getenv("LOGNAME")) username = getenv("LOGNAME");
-#if !defined _WIN32 && !defined ADB_HOST_ON_TARGET
-    if (username.empty() && getlogin()) username = getlogin();
-#endif
-    if (username.empty()) hostname = "unknown";
-
-    return " " + username + "@" + hostname;
-}
-
-static bool write_public_keyfile(RSA* private_key, const std::string& private_key_path) {
-    LOG(INFO) << "write_public_keyfile...";
-
+static bool calculate_public_key(std::string* out, RSA* private_key) {
     uint8_t binary_key_data[ANDROID_PUBKEY_ENCODED_SIZE];
     if (!android_pubkey_encode(private_key, binary_key_data, sizeof(binary_key_data))) {
         LOG(ERROR) << "Failed to convert to public key";
@@ -88,20 +66,10 @@
         return false;
     }
 
-    std::string content;
-    content.resize(expected_length);
-    size_t actual_length = EVP_EncodeBlock(reinterpret_cast<uint8_t*>(&content[0]), binary_key_data,
+    out->resize(expected_length);
+    size_t actual_length = EVP_EncodeBlock(reinterpret_cast<uint8_t*>(out->data()), binary_key_data,
                                            sizeof(binary_key_data));
-    content.resize(actual_length);
-
-    content += get_user_info();
-
-    std::string path(private_key_path + ".pub");
-    if (!android::base::WriteStringToFile(content, path)) {
-        PLOG(ERROR) << "Failed to write public key to '" << path << "'";
-        return false;
-    }
-
+    out->resize(actual_length);
     return true;
 }
 
@@ -140,11 +108,6 @@
         goto out;
     }
 
-    if (!write_public_keyfile(rsa, file)) {
-        D("Failed to write public key");
-        goto out;
-    }
-
     ret = 1;
 
 out:
@@ -170,36 +133,41 @@
     return result;
 }
 
-static bool read_key_file(const std::string& file) {
-    LOG(INFO) << "read_key_file '" << file << "'...";
-
+static std::shared_ptr<RSA> read_key_file(const std::string& file) {
     std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(file.c_str(), "r"), fclose);
     if (!fp) {
         PLOG(ERROR) << "Failed to open '" << file << "'";
-        return false;
+        return nullptr;
     }
 
     RSA* key = RSA_new();
     if (!PEM_read_RSAPrivateKey(fp.get(), &key, nullptr, nullptr)) {
         LOG(ERROR) << "Failed to read key";
         RSA_free(key);
+        return nullptr;
+    }
+
+    return std::shared_ptr<RSA>(key, RSA_free);
+}
+
+static bool load_key(const std::string& file) {
+    std::shared_ptr<RSA> key = read_key_file(file);
+    if (!key) {
         return false;
     }
 
     std::lock_guard<std::mutex> lock(g_keys_mutex);
-    std::string fingerprint = hash_key(key);
+    std::string fingerprint = hash_key(key.get());
     if (g_keys.find(fingerprint) != g_keys.end()) {
         LOG(INFO) << "ignoring already-loaded key: " << file;
-        RSA_free(key);
     } else {
-        g_keys[fingerprint] = std::shared_ptr<RSA>(key, RSA_free);
+        g_keys[fingerprint] = std::move(key);
     }
-
     return true;
 }
 
-static bool read_keys(const std::string& path, bool allow_dir = true) {
-    LOG(INFO) << "read_keys '" << path << "'...";
+static bool load_keys(const std::string& path, bool allow_dir = true) {
+    LOG(INFO) << "load_keys '" << path << "'...";
 
     struct stat st;
     if (stat(path.c_str(), &st) != 0) {
@@ -208,7 +176,7 @@
     }
 
     if (S_ISREG(st.st_mode)) {
-        return read_key_file(path);
+        return load_key(path);
     } else if (S_ISDIR(st.st_mode)) {
         if (!allow_dir) {
             // inotify isn't recursive. It would break expectations to load keys in nested
@@ -237,7 +205,7 @@
                 continue;
             }
 
-            result |= read_key_file((path + OS_PATH_SEPARATOR + name));
+            result |= load_key((path + OS_PATH_SEPARATOR + name));
         }
         return result;
     }
@@ -250,7 +218,7 @@
     return adb_get_android_dir_path() + OS_PATH_SEPARATOR + "adbkey";
 }
 
-static bool get_user_key() {
+static bool generate_userkey() {
     std::string path = get_user_key_path();
     if (path.empty()) {
         PLOG(ERROR) << "Error getting user key filename";
@@ -266,7 +234,7 @@
         }
     }
 
-    return read_key_file(path);
+    return load_key(path);
 }
 
 static std::set<std::string> get_vendor_keys() {
@@ -320,26 +288,42 @@
     return result;
 }
 
+static bool pubkey_from_privkey(std::string* out, const std::string& path) {
+    std::shared_ptr<RSA> privkey = read_key_file(path);
+    if (!privkey) {
+        return false;
+    }
+    return calculate_public_key(out, privkey.get());
+}
+
 std::string adb_auth_get_userkey() {
     std::string path = get_user_key_path();
     if (path.empty()) {
         PLOG(ERROR) << "Error getting user key filename";
         return "";
     }
-    path += ".pub";
 
-    std::string content;
-    if (!android::base::ReadFileToString(path, &content)) {
-        PLOG(ERROR) << "Can't load '" << path << "'";
+    std::string result;
+    if (!pubkey_from_privkey(&result, path)) {
         return "";
     }
-    return content;
+    return result;
 }
 
 int adb_auth_keygen(const char* filename) {
     return (generate_key(filename) == 0);
 }
 
+int adb_auth_pubkey(const char* filename) {
+    std::string pubkey;
+    if (!pubkey_from_privkey(&pubkey, filename)) {
+        return 1;
+    }
+    pubkey.push_back('\n');
+
+    return WriteFdExactly(STDOUT_FILENO, pubkey.data(), pubkey.size()) ? 0 : 1;
+}
+
 #if defined(__linux__)
 static void adb_auth_inotify_update(int fd, unsigned fd_event, void*) {
     LOG(INFO) << "adb_auth_inotify_update called";
@@ -380,7 +364,7 @@
                     LOG(INFO) << "ignoring new directory at '" << path << "'";
                 } else {
                     LOG(INFO) << "observed new file at '" << path << "'";
-                    read_keys(path, false);
+                    load_keys(path, false);
                 }
             } else {
                 LOG(WARNING) << "unmonitored event for " << path << ": 0x" << std::hex
@@ -420,8 +404,8 @@
 void adb_auth_init() {
     LOG(INFO) << "adb_auth_init...";
 
-    if (!get_user_key()) {
-        LOG(ERROR) << "Failed to get user key";
+    if (!generate_userkey()) {
+        LOG(ERROR) << "Failed to generate user key";
         return;
     }
 
@@ -432,7 +416,7 @@
 #endif
 
     for (const std::string& path : key_paths) {
-        read_keys(path.c_str());
+        load_keys(path.c_str());
     }
 }
 
diff --git a/adb/client/commandline.cpp b/adb/client/commandline.cpp
index b5bed28..95e66ae 100644
--- a/adb/client/commandline.cpp
+++ b/adb/client/commandline.cpp
@@ -146,10 +146,8 @@
         " install [-lrtsdg] [--instant] PACKAGE\n"
         " install-multiple [-lrtsdpg] [--instant] PACKAGE...\n"
         "     push package(s) to the device and install them\n"
-        "     -l: forward lock application\n"
         "     -r: replace existing application\n"
         "     -t: allow test packages\n"
-        "     -s: install application on sdcard\n"
         "     -d: allow version code downgrade (debuggable packages only)\n"
         "     -p: partial application install (install-multiple only)\n"
         "     -g: grant all runtime permissions\n"
@@ -185,7 +183,6 @@
         " enable-verity            re-enable dm-verity checking on userdebug builds\n"
         " keygen FILE\n"
         "     generate adb public/private key; private key stored in FILE,\n"
-        "     public key stored in FILE.pub (existing files overwritten)\n"
         "\n"
         "scripting:\n"
         " wait-for[-TRANSPORT]-STATE\n"
@@ -1756,14 +1753,14 @@
         // Always print key generation information for keygen command.
         adb_trace_enable(AUTH);
         return adb_auth_keygen(argv[1]);
-    }
-    else if (!strcmp(argv[0], "jdwp")) {
+    } else if (!strcmp(argv[0], "pubkey")) {
+        if (argc != 2) error_exit("pubkey requires an argument");
+        return adb_auth_pubkey(argv[1]);
+    } else if (!strcmp(argv[0], "jdwp")) {
         return adb_connect_command("jdwp");
-    }
-    else if (!strcmp(argv[0], "track-jdwp")) {
+    } else if (!strcmp(argv[0], "track-jdwp")) {
         return adb_connect_command("track-jdwp");
-    }
-    else if (!strcmp(argv[0], "track-devices")) {
+    } else if (!strcmp(argv[0], "track-devices")) {
         return adb_connect_command("host:track-devices");
     } else if (!strcmp(argv[0], "raw")) {
         if (argc != 2) {
@@ -1772,13 +1769,11 @@
         return adb_connect_command(argv[1]);
     }
 
-
     /* "adb /?" is a common idiom under Windows */
     else if (!strcmp(argv[0], "--help") || !strcmp(argv[0], "help") || !strcmp(argv[0], "/?")) {
         help();
         return 0;
-    }
-    else if (!strcmp(argv[0], "--version") || !strcmp(argv[0], "version")) {
+    } else if (!strcmp(argv[0], "--version") || !strcmp(argv[0], "version")) {
         fprintf(stdout, "%s", adb_version().c_str());
         return 0;
     } else if (!strcmp(argv[0], "features")) {
diff --git a/adb/client/fastdeploy.cpp b/adb/client/fastdeploy.cpp
index 45f3cca..e82f15a 100644
--- a/adb/client/fastdeploy.cpp
+++ b/adb/client/fastdeploy.cpp
@@ -228,11 +228,12 @@
             android::base::StringPrintf(kAgentExtractCommandPattern, packageName.c_str());
 
     std::vector<char> extractErrorBuffer;
-    int statusCode;
-    DeployAgentFileCallback cb(outputFp, &extractErrorBuffer, &statusCode);
+    DeployAgentFileCallback cb(outputFp, &extractErrorBuffer);
     int returnCode = send_shell_command(extractCommand, false, &cb);
     if (returnCode != 0) {
-        error_exit("Executing %s returned %d", extractCommand.c_str(), returnCode);
+        fprintf(stderr, "Executing %s returned %d\n", extractCommand.c_str(), returnCode);
+        fprintf(stderr, "%*s\n", int(extractErrorBuffer.size()), extractErrorBuffer.data());
+        error_exit("Aborting");
     }
 }
 
diff --git a/adb/client/fastdeploycallbacks.cpp b/adb/client/fastdeploycallbacks.cpp
index 6c9a21f..23a0aca 100644
--- a/adb/client/fastdeploycallbacks.cpp
+++ b/adb/client/fastdeploycallbacks.cpp
@@ -35,8 +35,7 @@
 
 class DeployAgentBufferCallback : public StandardStreamsCallbackInterface {
   public:
-    DeployAgentBufferCallback(std::vector<char>* outBuffer, std::vector<char>* errBuffer,
-                              int* statusCode);
+    DeployAgentBufferCallback(std::vector<char>* outBuffer, std::vector<char>* errBuffer);
 
     virtual void OnStdout(const char* buffer, int length);
     virtual void OnStderr(const char* buffer, int length);
@@ -45,27 +44,17 @@
   private:
     std::vector<char>* mpOutBuffer;
     std::vector<char>* mpErrBuffer;
-    int* mpStatusCode;
 };
 
 int capture_shell_command(const char* command, std::vector<char>* outBuffer,
                           std::vector<char>* errBuffer) {
-    int statusCode;
-    DeployAgentBufferCallback cb(outBuffer, errBuffer, &statusCode);
-    int ret = send_shell_command(command, false, &cb);
-
-    if (ret == 0) {
-        return statusCode;
-    } else {
-        return ret;
-    }
+    DeployAgentBufferCallback cb(outBuffer, errBuffer);
+    return send_shell_command(command, false, &cb);
 }
 
-DeployAgentFileCallback::DeployAgentFileCallback(FILE* outputFile, std::vector<char>* errBuffer,
-                                                 int* statusCode) {
+DeployAgentFileCallback::DeployAgentFileCallback(FILE* outputFile, std::vector<char>* errBuffer) {
     mpOutFile = outputFile;
     mpErrBuffer = errBuffer;
-    mpStatusCode = statusCode;
     mBytesWritten = 0;
 }
 
@@ -84,10 +73,7 @@
 }
 
 int DeployAgentFileCallback::Done(int status) {
-    if (mpStatusCode != NULL) {
-        *mpStatusCode = status;
-    }
-    return 0;
+    return status;
 }
 
 int DeployAgentFileCallback::getBytesWritten() {
@@ -95,11 +81,9 @@
 }
 
 DeployAgentBufferCallback::DeployAgentBufferCallback(std::vector<char>* outBuffer,
-                                                     std::vector<char>* errBuffer,
-                                                     int* statusCode) {
+                                                     std::vector<char>* errBuffer) {
     mpOutBuffer = outBuffer;
     mpErrBuffer = errBuffer;
-    mpStatusCode = statusCode;
 }
 
 void DeployAgentBufferCallback::OnStdout(const char* buffer, int length) {
@@ -111,8 +95,5 @@
 }
 
 int DeployAgentBufferCallback::Done(int status) {
-    if (mpStatusCode != NULL) {
-        *mpStatusCode = status;
-    }
-    return 0;
+    return status;
 }
diff --git a/adb/client/fastdeploycallbacks.h b/adb/client/fastdeploycallbacks.h
index b428b50..7e049c5 100644
--- a/adb/client/fastdeploycallbacks.h
+++ b/adb/client/fastdeploycallbacks.h
@@ -21,7 +21,7 @@
 
 class DeployAgentFileCallback : public StandardStreamsCallbackInterface {
   public:
-    DeployAgentFileCallback(FILE* outputFile, std::vector<char>* errBuffer, int* statusCode);
+    DeployAgentFileCallback(FILE* outputFile, std::vector<char>* errBuffer);
 
     virtual void OnStdout(const char* buffer, int length);
     virtual void OnStderr(const char* buffer, int length);
@@ -33,7 +33,6 @@
     FILE* mpOutFile;
     std::vector<char>* mpErrBuffer;
     int mBytesWritten;
-    int* mpStatusCode;
 };
 
 int capture_shell_command(const char* command, std::vector<char>* outBuffer,
diff --git a/adb/fastdeploy/OWNERS b/adb/fastdeploy/OWNERS
new file mode 100644
index 0000000..d145834
--- /dev/null
+++ b/adb/fastdeploy/OWNERS
@@ -0,0 +1 @@
+idries@google.com
diff --git a/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java b/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
index cd6f168..17845e2 100644
--- a/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
+++ b/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
@@ -142,14 +142,21 @@
         BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
 
         String packagePrefix = "package:";
+        String packageSuffix = "=" + packageName;
         String line = "";
         while ((line = reader.readLine()) != null) {
-            int packageIndex = line.indexOf(packagePrefix);
-            int equalsIndex = line.indexOf("=" + packageName);
-            return new File(line.substring(packageIndex + packagePrefix.length(), equalsIndex));
+            if (line.endsWith(packageSuffix)) {
+                int packageIndex = line.indexOf(packagePrefix);
+                if (packageIndex == -1) {
+                    throw new IOException("error reading package list");
+                }
+                int equalsIndex = line.lastIndexOf(packageSuffix);
+                String fileName =
+                    line.substring(packageIndex + packagePrefix.length(), equalsIndex);
+                return new File(fileName);
+            }
         }
-
-        return null;
+        throw new IOException("package not found");
     }
 
     private static void extractMetaData(String packageName) throws IOException {
diff --git a/adb/fastdeploy/deploypatchgenerator/src/com/android/fastdeploy/DeployPatchGenerator.java b/adb/fastdeploy/deploypatchgenerator/src/com/android/fastdeploy/DeployPatchGenerator.java
index 5577364..24b2eab 100644
--- a/adb/fastdeploy/deploypatchgenerator/src/com/android/fastdeploy/DeployPatchGenerator.java
+++ b/adb/fastdeploy/deploypatchgenerator/src/com/android/fastdeploy/DeployPatchGenerator.java
@@ -61,22 +61,22 @@
             File hostFile = new File(apkPath);
 
             List<APKEntry> deviceZipEntries = getMetadataFromFile(deviceMetadataPath);
+            System.err.println("Device Entries (" + deviceZipEntries.size() + ")");
             if (verbose) {
                 sb = new StringBuilder();
                 for (APKEntry entry : deviceZipEntries) {
                     APKEntryToString(entry, sb);
                 }
-                System.err.println("Device Entries (" + deviceZipEntries.size() + ")");
                 System.err.println(sb.toString());
             }
 
             List<APKEntry> hostFileEntries = PatchUtils.getAPKMetaData(hostFile).getEntriesList();
+            System.err.println("Host Entries (" + hostFileEntries.size() + ")");
             if (verbose) {
                 sb = new StringBuilder();
                 for (APKEntry entry : hostFileEntries) {
                     APKEntryToString(entry, sb);
                 }
-                System.err.println("Host Entries (" + hostFileEntries.size() + ")");
                 System.err.println(sb.toString());
             }
 
@@ -130,7 +130,8 @@
 
         for (APKEntry deviceZipEntry : deviceZipEntries) {
             for (APKEntry hostZipEntry : hostZipEntries) {
-                if (deviceZipEntry.getCrc32() == hostZipEntry.getCrc32()) {
+                if (deviceZipEntry.getCrc32() == hostZipEntry.getCrc32() &&
+                    deviceZipEntry.getFileName().equals(hostZipEntry.getFileName())) {
                     identicalContents.add(new SimpleEntry(deviceZipEntry, hostZipEntry));
                 }
             }
diff --git a/adb/transport.cpp b/adb/transport.cpp
index c2d4917..8741654 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -764,6 +764,10 @@
 #if ADB_HOST
         if (t->IsTcpDevice() && !t->kicked()) {
             D("transport: %s unref (attempting reconnection)", t->serial.c_str());
+
+            // We need to clear the transport's keys, so that on the next connection, it tries
+            // again from the beginning.
+            t->ResetKeys();
             reconnect_handler.TrackTransport(t);
         } else {
             D("transport: %s unref (kicking and closing)", t->serial.c_str());
@@ -1009,14 +1013,11 @@
 const FeatureSet& supported_features() {
     // Local static allocation to avoid global non-POD variables.
     static const FeatureSet* features = new FeatureSet{
-        kFeatureShell2, kFeatureCmd, kFeatureStat2, kFeatureFixedPushMkdir,
-#if ADB_HOST
-                kFeatureApex
-#endif
-        // Increment ADB_SERVER_VERSION when adding a feature that adbd needs
-        // to know about. Otherwise, the client can be stuck running an old
-        // version of the server even after upgrading their copy of adb.
-        // (http://b/24370690)
+            kFeatureShell2, kFeatureCmd, kFeatureStat2, kFeatureFixedPushMkdir, kFeatureApex
+            // Increment ADB_SERVER_VERSION when adding a feature that adbd needs
+            // to know about. Otherwise, the client can be stuck running an old
+            // version of the server even after upgrading their copy of adb.
+            // (http://b/24370690)
     };
 
     return *features;
@@ -1331,10 +1332,20 @@
 
 #if ADB_HOST
 std::shared_ptr<RSA> atransport::NextKey() {
-    if (keys_.empty()) keys_ = adb_auth_get_private_keys();
+    if (keys_.empty()) {
+        LOG(INFO) << "fetching keys for transport " << this->serial_name();
+        keys_ = adb_auth_get_private_keys();
+
+        // We should have gotten at least one key: the one that's automatically generated.
+        CHECK(!keys_.empty());
+    }
 
     std::shared_ptr<RSA> result = keys_[0];
     keys_.pop_front();
     return result;
 }
+
+void atransport::ResetKeys() {
+    keys_.clear();
+}
 #endif
diff --git a/adb/transport.h b/adb/transport.h
index 9894bdf..d593700 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -258,6 +258,7 @@
 
 #if ADB_HOST
     std::shared_ptr<RSA> NextKey();
+    void ResetKeys();
 #endif
 
     char token[TOKEN_SIZE] = {};
diff --git a/base/file.cpp b/base/file.cpp
index d5bb7fe..2f4a517 100644
--- a/base/file.cpp
+++ b/base/file.cpp
@@ -22,6 +22,7 @@
 #include <libgen.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
diff --git a/base/include/android-base/unique_fd.h b/base/include/android-base/unique_fd.h
index 4e3879b..4e6c879 100644
--- a/base/include/android-base/unique_fd.h
+++ b/base/include/android-base/unique_fd.h
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include <dirent.h>
 #include <fcntl.h>
 
 #if !defined(_WIN32)
@@ -231,3 +232,13 @@
 template <typename T>
 int close(const android::base::unique_fd_impl<T>&)
     __attribute__((__unavailable__("close called on unique_fd")));
+
+template <typename T>
+FILE* fdopen(const android::base::unique_fd_impl<T>&, const char* mode)
+    __attribute__((__unavailable__("fdopen takes ownership of the fd passed in; either dup the "
+                                   "unique_fd, or use android::base::Fdopen to pass ownership")));
+
+template <typename T>
+DIR* fdopendir(const android::base::unique_fd_impl<T>&) __attribute__((
+    __unavailable__("fdopendir takes ownership of the fd passed in; either dup the "
+                    "unique_fd, or use android::base::Fdopendir to pass ownership")));
diff --git a/base/logging.cpp b/base/logging.cpp
index bd09069..f89168c 100644
--- a/base/logging.cpp
+++ b/base/logging.cpp
@@ -417,6 +417,14 @@
   }
   std::string msg(data_->ToString());
 
+  if (data_->GetSeverity() == FATAL) {
+#ifdef __ANDROID__
+    // Set the bionic abort message early to avoid liblog doing it
+    // with the individual lines, so that we get the whole message.
+    android_set_abort_message(msg.c_str());
+#endif
+  }
+
   {
     // Do the actual logging with the lock held.
     std::lock_guard<std::mutex> lock(LoggingLock());
diff --git a/cpio/Android.bp b/cpio/Android.bp
index 847e0f1..baa0319 100644
--- a/cpio/Android.bp
+++ b/cpio/Android.bp
@@ -5,4 +5,7 @@
     srcs: ["mkbootfs.c"],
     cflags: ["-Werror"],
     shared_libs: ["libcutils"],
+    dist: {
+        targets: ["dist_files"],
+    },
 }
diff --git a/cpio/Android.mk b/cpio/Android.mk
deleted file mode 100644
index fc3551b..0000000
--- a/cpio/Android.mk
+++ /dev/null
@@ -1,3 +0,0 @@
-# Copyright 2005 The Android Open Source Project
-
-$(call dist-for-goals,dist_files,$(ALL_MODULES.mkbootfs.BUILT))
diff --git a/debuggerd/Android.bp b/debuggerd/Android.bp
index 03b3287..d9fae52 100644
--- a/debuggerd/Android.bp
+++ b/debuggerd/Android.bp
@@ -9,7 +9,6 @@
         "-Wno-nullability-completeness",
         "-Os",
     ],
-    cpp_std: "gnu++17",
 
     local_include_dirs: ["include"],
 }
diff --git a/debuggerd/crash_dump.cpp b/debuggerd/crash_dump.cpp
index 577e336..d79d20b 100644
--- a/debuggerd/crash_dump.cpp
+++ b/debuggerd/crash_dump.cpp
@@ -348,8 +348,16 @@
   return vm_pid;
 }
 
+static void InstallSigPipeHandler() {
+  struct sigaction action = {};
+  action.sa_handler = SIG_IGN;
+  action.sa_flags = SA_RESTART;
+  sigaction(SIGPIPE, &action, nullptr);
+}
+
 int main(int argc, char** argv) {
   DefuseSignalHandlers();
+  InstallSigPipeHandler();
 
   atrace_begin(ATRACE_TAG, "before reparent");
   pid_t target_process = getppid();
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 0b8a936..1179263 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -78,7 +78,7 @@
   _LOG(log, logtype::HEADER, "ABI: '%s'\n", ABI_STRING);
 }
 
-static void dump_probable_cause(log_t* log, const siginfo_t* si) {
+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) {
     if (si->si_addr < reinterpret_cast<void*>(4096)) {
@@ -94,6 +94,14 @@
     } else if (si->si_addr == reinterpret_cast<void*>(0xffff0f60)) {
       cause = "call to kuser_cmpxchg64";
     }
+  } else if (si->si_signo == SIGSEGV && si->si_code == SEGV_ACCERR) {
+    for (auto it = map->begin(); it != map->end(); ++it) {
+      const backtrace_map_t* entry = *it;
+      if (si->si_addr >= reinterpret_cast<void*>(entry->start) &&
+          si->si_addr < reinterpret_cast<void*>(entry->end) && entry->flags == PROT_EXEC) {
+        cause = "execute-only (no-read) memory access error; likely due to data in .text.";
+      }
+    }
   } else if (si->si_signo == SIGSYS && si->si_code == SYS_SECCOMP) {
     cause = StringPrintf("seccomp prevented call to disallowed %s system call %d", ABI_STRING,
                          si->si_syscall);
@@ -125,8 +133,6 @@
   _LOG(log, logtype::HEADER, "signal %d (%s), code %d (%s%s), fault addr %s\n",
        thread_info.siginfo->si_signo, get_signame(thread_info.siginfo),
        thread_info.siginfo->si_code, get_sigcode(thread_info.siginfo), sender_desc, addr_desc);
-
-  dump_probable_cause(log, thread_info.siginfo);
 }
 
 static void dump_thread_info(log_t* log, const ThreadInfo& thread_info) {
@@ -426,6 +432,7 @@
 
   if (thread_info.siginfo) {
     dump_signal_info(log, thread_info, process_memory);
+    dump_probable_cause(log, thread_info.siginfo, map);
   }
 
   if (primary_thread) {
diff --git a/fastboot/Android.bp b/fastboot/Android.bp
index faed376..ead2105 100644
--- a/fastboot/Android.bp
+++ b/fastboot/Android.bp
@@ -144,8 +144,6 @@
     static_libs: [
         "libhealthhalutils",
     ],
-
-    cpp_std: "c++17",
 }
 
 cc_defaults {
@@ -212,7 +210,6 @@
     name: "libfastboot",
     defaults: ["fastboot_host_defaults"],
 
-    cpp_std: "c++17",
     srcs: [
         "bootimg_utils.cpp",
         "fastboot.cpp",
@@ -260,6 +257,13 @@
         "mke2fs",
         "make_f2fs",
     ],
+    dist: {
+        targets: [
+            "dist_files",
+            "sdk",
+            "win_sdk",
+        ],
+    },
 
     target: {
         not_windows: {
diff --git a/fastboot/Android.mk b/fastboot/Android.mk
index e4c1317..17ec392 100644
--- a/fastboot/Android.mk
+++ b/fastboot/Android.mk
@@ -18,13 +18,9 @@
 # Package fastboot-related executables.
 #
 
-my_dist_files := $(HOST_OUT_EXECUTABLES)/fastboot
-my_dist_files += $(HOST_OUT_EXECUTABLES)/mke2fs
+my_dist_files := $(HOST_OUT_EXECUTABLES)/mke2fs
 my_dist_files += $(HOST_OUT_EXECUTABLES)/e2fsdroid
 my_dist_files += $(HOST_OUT_EXECUTABLES)/make_f2fs
 my_dist_files += $(HOST_OUT_EXECUTABLES)/sload_f2fs
 $(call dist-for-goals,dist_files sdk win_sdk,$(my_dist_files))
-ifdef HOST_CROSS_OS
-$(call dist-for-goals,dist_files sdk win_sdk,$(ALL_MODULES.host_cross_fastboot.BUILT))
-endif
 my_dist_files :=
diff --git a/fastboot/device/flashing.cpp b/fastboot/device/flashing.cpp
index 7b99884..fbba631 100644
--- a/fastboot/device/flashing.cpp
+++ b/fastboot/device/flashing.cpp
@@ -153,6 +153,7 @@
         if (!FlashPartitionTable(super_name, *new_metadata.get())) {
             return device->WriteFail("Unable to flash new partition table");
         }
+        fs_mgr_overlayfs_teardown();
         return device->WriteOkay("Successfully flashed partition table");
     }
 
@@ -186,5 +187,6 @@
     if (!UpdateAllPartitionMetadata(super_name, *new_metadata.get())) {
         return device->WriteFail("Unable to write new partition table");
     }
+    fs_mgr_overlayfs_teardown();
     return device->WriteOkay("Successfully updated partition table");
 }
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index e066bff..0b8d9b2 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -46,6 +46,7 @@
 #include <chrono>
 #include <functional>
 #include <regex>
+#include <string>
 #include <thread>
 #include <utility>
 #include <vector>
@@ -78,6 +79,7 @@
 using android::base::Split;
 using android::base::Trim;
 using android::base::unique_fd;
+using namespace std::string_literals;
 
 static const char* serial = nullptr;
 
@@ -162,9 +164,17 @@
         // clang-format on
 };
 
-static std::string find_item_given_name(const std::string& img_name) {
+static char* get_android_product_out() {
     char* dir = getenv("ANDROID_PRODUCT_OUT");
     if (dir == nullptr || dir[0] == '\0') {
+        return nullptr;
+    }
+    return dir;
+}
+
+static std::string find_item_given_name(const std::string& img_name) {
+    char* dir = get_android_product_out();
+    if (!dir) {
         die("ANDROID_PRODUCT_OUT not set");
     }
     return std::string(dir) + "/" + img_name;
@@ -1098,6 +1108,14 @@
     return fb->GetVar("is-logical:" + partition, &value) == fastboot::SUCCESS && value == "yes";
 }
 
+static bool is_retrofit_device() {
+    std::string value;
+    if (fb->GetVar("super-partition-name", &value) != fastboot::SUCCESS) {
+        return false;
+    }
+    return android::base::StartsWith(value, "system_");
+}
+
 static void do_flash(const char* pname, const char* fname) {
     struct fastboot_buffer buf;
 
@@ -1140,6 +1158,10 @@
     std::this_thread::sleep_for(std::chrono::milliseconds(1000));
 
     fb->set_transport(open_device());
+
+    if (!is_userspace_fastboot()) {
+        die("Failed to boot into userspace fastboot; one or more components might be unbootable.");
+    }
 }
 
 class ImageSource {
@@ -1296,9 +1318,6 @@
     if (!is_userspace_fastboot()) {
         reboot_to_userspace_fastboot();
     }
-    if (!is_userspace_fastboot()) {
-        die("Failed to boot into userspace; one or more components might be unbootable.");
-    }
 
     std::string super_name;
     if (fb->GetVar("super-partition-name", &super_name) != fastboot::RetCode::SUCCESS) {
@@ -1311,6 +1330,19 @@
         command += ":wipe";
     }
     fb->RawCommand(command, "Updating super partition");
+
+    // Retrofit devices have two super partitions, named super_a and super_b.
+    // On these devices, secondary slots must be flashed as physical
+    // partitions (otherwise they would not mount on first boot). To enforce
+    // this, we delete any logical partitions for the "other" slot.
+    if (is_retrofit_device()) {
+        for (const auto& [image, slot] : os_images_) {
+            std::string partition_name = image->part_name + "_"s + slot;
+            if (image->IsSecondary() && is_logical(partition_name)) {
+                fb->DeletePartition(partition_name);
+            }
+        }
+    }
 }
 
 class ZipImageSource final : public ImageSource {
@@ -1466,15 +1498,13 @@
             fprintf(stderr, "File system type %s not supported.\n", partition_type.c_str());
             return;
         }
-        fprintf(stderr, "Formatting is not supported for file system with type '%s'.\n",
-                partition_type.c_str());
-        return;
+        die("Formatting is not supported for file system with type '%s'.",
+            partition_type.c_str());
     }
 
     int64_t size;
     if (!android::base::ParseInt(partition_size, &size)) {
-        fprintf(stderr, "Couldn't parse partition size '%s'.\n", partition_size.c_str());
-        return;
+        die("Couldn't parse partition size '%s'.", partition_size.c_str());
     }
 
     unsigned eraseBlkSize, logicalBlkSize;
@@ -1484,17 +1514,14 @@
     if (fs_generator_generate(gen, output.path, size, initial_dir,
             eraseBlkSize, logicalBlkSize)) {
         die("Cannot generate image for %s", partition.c_str());
-        return;
     }
 
     fd.reset(open(output.path, O_RDONLY));
     if (fd == -1) {
-        fprintf(stderr, "Cannot open generated image: %s\n", strerror(errno));
-        return;
+        die("Cannot open generated image: %s", strerror(errno));
     }
     if (!load_buf_fd(fd.release(), &buf)) {
-        fprintf(stderr, "Cannot read image: %s\n", strerror(errno));
-        return;
+        die("Cannot read image: %s", strerror(errno));
     }
     flash_buf(partition, &buf);
     return;
@@ -1505,11 +1532,17 @@
         if (errMsg) fprintf(stderr, "%s", errMsg);
     }
     fprintf(stderr, "FAILED (%s)\n", fb->Error().c_str());
+    if (!skip_if_not_supported) {
+        die("Command failed");
+    }
 }
 
 static bool should_flash_in_userspace(const std::string& partition_name) {
+    if (!get_android_product_out()) {
+        return false;
+    }
     auto path = find_item_given_name("super_empty.img");
-    if (path.empty()) {
+    if (path.empty() || access(path.c_str(), R_OK)) {
         return false;
     }
     auto metadata = android::fs_mgr::ReadFromImageFile(path);
@@ -1930,8 +1963,7 @@
         fb->RebootTo("recovery");
         fb->WaitForDisconnect();
     } else if (wants_reboot_fastboot) {
-        fb->RebootTo("fastboot");
-        fb->WaitForDisconnect();
+        reboot_to_userspace_fastboot();
     }
 
     fprintf(stderr, "Finished. Total time: %.3fs\n", (now() - start));
diff --git a/fastboot/fs.cpp b/fastboot/fs.cpp
index fc6a16b..8c0aa6b 100644
--- a/fastboot/fs.cpp
+++ b/fastboot/fs.cpp
@@ -172,13 +172,8 @@
     mkf2fs_args.push_back("-S");
     std::string size_str = std::to_string(partSize);
     mkf2fs_args.push_back(size_str.c_str());
-    mkf2fs_args.push_back("-f");
-    mkf2fs_args.push_back("-O");
-    mkf2fs_args.push_back("encrypt");
-    mkf2fs_args.push_back("-O");
-    mkf2fs_args.push_back("quota");
-    mkf2fs_args.push_back("-O");
-    mkf2fs_args.push_back("verity");
+    mkf2fs_args.push_back("-g");
+    mkf2fs_args.push_back("android");
     mkf2fs_args.push_back(fileName);
     mkf2fs_args.push_back(nullptr);
 
diff --git a/fs_mgr/Android.bp b/fs_mgr/Android.bp
index 6c8a943..99231ac 100644
--- a/fs_mgr/Android.bp
+++ b/fs_mgr/Android.bp
@@ -25,9 +25,6 @@
         "-Werror",
         "-Wno-unused-variable",
     ],
-    cppflags: [
-        "-std=gnu++1z",
-    ],
 }
 
 cc_library {
@@ -42,8 +39,6 @@
         "fs_mgr.cpp",
         "fs_mgr_format.cpp",
         "fs_mgr_verity.cpp",
-        "fs_mgr_avb.cpp",
-        "fs_mgr_avb_ops.cpp",
         "fs_mgr_dm_linear.cpp",
         "fs_mgr_overlayfs.cpp",
         "fs_mgr_vendor_overlay.cpp",
@@ -61,10 +56,12 @@
     ],
     static_libs: [
         "libavb",
+        "libfs_avb",
         "libfstab",
         "libdm",
     ],
     export_static_lib_headers: [
+        "libfs_avb",
         "libfstab",
         "libdm",
     ],
@@ -104,3 +101,28 @@
     export_include_dirs: ["include_fstab"],
     header_libs: ["libbase_headers"],
 }
+
+cc_library_static {
+    name: "libfs_avb",
+    defaults: ["fs_mgr_defaults"],
+    recovery_available: true,
+    export_include_dirs: ["libfs_avb/include"],
+    srcs: [
+        "libfs_avb/avb_ops.cpp",
+        "libfs_avb/fs_avb.cpp",
+    ],
+    static_libs: [
+        "libavb",
+        "libfstab",
+        "libdm",
+    ],
+    export_static_lib_headers: [
+        "libfstab",
+    ],
+    shared_libs: [
+        "libcrypto",
+    ],
+    header_libs: [
+        "libbase_headers",
+    ],
+}
diff --git a/fs_mgr/README.overlayfs.md b/fs_mgr/README.overlayfs.md
new file mode 100644
index 0000000..fbb5f5d
--- /dev/null
+++ b/fs_mgr/README.overlayfs.md
@@ -0,0 +1,109 @@
+Android Overlayfs integration with adb remount
+==============================================
+
+Introduction
+------------
+
+Users working with userdebug or eng builds expect to be able to
+remount the system partition as read-write and then add or modify
+any number of files without reflashing the system image, which is
+understandably efficient for a development cycle.
+Limited memory systems that chose to use readonly filesystems like
+*squashfs*, or *Logical Resizable Android Partitions* which land
+system partition images right-sized, and with filesystem that have
+been deduped on the block level to compress the content; means that
+either a remount is not possible directly, or when done offers
+little or no utility because of remaining space limitations or
+support logistics.
+
+*Overlayfs* comes to the rescue for these debug scenarios, and logic
+will _automatically_ setup backing storage for a writable filesystem
+as an upper reference, and mount overtop the lower.  These actions
+will be performed in the **adb disable-verity** and **adb remount**
+requests.
+
+Operations
+----------
+
+### Cookbook
+
+The typical action to utilize the remount facility is:
+
+    $ adb root
+    $ adb disable-verity
+    $ adb reboot
+    $ adb wait-for-device
+    $ adb root
+    $ adb remount
+
+Followed by one of the following:
+
+    $ adb stop
+    $ adb sync
+    $ adb start
+    $ adb reboot
+
+*or*
+
+    $ adb push <source> <destination>
+    $ adb reboot
+
+Note that the sequence above:
+
+    $ adb disable-verity
+    $ adb reboot
+
+can be replaced with:
+
+    $ adb reboot -R
+
+which will not reboot if everything is already prepared and ready
+to go.
+
+None of this changes if *overlayfs* needs to be engaged.
+The decisions whether to use traditional direct filesystem remount,
+or one wrapped by *overlayfs* is automatically determined based on
+a probe of the filesystem types and space remaining.
+
+### Backing Storage
+
+When *overlayfs* logic is feasible, it will use either the
+**/cache/overlay/** directory for non-A/B devices, or the
+**/mnt/scratch/overlay** directory for A/B devices that have
+access to *Logical Resizeable Android Partitions*.
+The backing store is used as soon as possible in the boot
+process and can occur at first stage init, or at the
+mount_all init rc commands.
+
+This early as possible attachment of *overlayfs* means that
+*sepolicy* or *init* itself can also be pushed and used after
+the exec phases that accompany each stage.
+
+Caveats
+-------
+
+- Space used in the backing storage is on a file by file basis
+  and will require more space than if updated in place.
+- 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.
+- For implementation simplicity on retrofit dynamic partition devices,
+  take the whole alternate super (eg: if "*a*" slot, then the whole of
+  "*system_b*").
+  Since landing a filesystem on the alternate super physical device
+  without differentiating if it is setup to support logical or physical,
+  the alternate slot metadata and previous content will be lost.
+- If dynamic partitions runs out of space, resizing a logical
+  partition larger may fail because of the scratch partition.
+  If this happens, either fastboot flashall or adb enable-verity can
+  be used to clear scratch storage to permit the flash.
+  Then reinstate the overrides and continue.
+- File bugs or submit fixes for review.
diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 8e57e1e..d1eabab 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -20,6 +20,7 @@
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <libgen.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -34,6 +35,7 @@
 #include <unistd.h>
 
 #include <functional>
+#include <map>
 #include <memory>
 #include <string>
 #include <thread>
@@ -53,6 +55,7 @@
 #include <ext4_utils/ext4_sb.h>
 #include <ext4_utils/ext4_utils.h>
 #include <ext4_utils/wipe.h>
+#include <fs_avb/fs_avb.h>
 #include <fs_mgr_overlayfs.h>
 #include <libdm/dm.h>
 #include <liblp/metadata_format.h>
@@ -62,7 +65,6 @@
 #include <log/log_properties.h>
 #include <logwrap/logwrap.h>
 
-#include "fs_mgr_avb.h"
 #include "fs_mgr_priv.h"
 
 #define KEY_LOC_PROP   "ro.crypto.keyfile.userdata"
@@ -80,8 +82,16 @@
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
 
+using android::base::Realpath;
+using android::base::StartsWith;
+using android::base::unique_fd;
 using android::dm::DeviceMapper;
 using android::dm::DmDeviceState;
+using android::fs_mgr::AvbHandle;
+using android::fs_mgr::AvbHashtreeResult;
+using android::fs_mgr::AvbUniquePtr;
+
+using namespace std::literals;
 
 // record fs stat
 enum FsStatFlags {
@@ -95,7 +105,7 @@
     FS_STAT_FULL_MOUNT_FAILED = 0x0100,
     FS_STAT_E2FSCK_FAILED = 0x0200,
     FS_STAT_E2FSCK_FS_FIXED = 0x0400,
-    FS_STAT_EXT4_INVALID_MAGIC = 0x0800,
+    FS_STAT_INVALID_MAGIC = 0x0800,
     FS_STAT_TOGGLE_QUOTAS_FAILED = 0x10000,
     FS_STAT_SET_RESERVED_BLOCKS_FAILED = 0x20000,
     FS_STAT_ENABLE_ENCRYPTION_FAILED = 0x40000,
@@ -123,10 +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)) {
@@ -138,6 +148,18 @@
     return fs_type == "ext4" || fs_type == "ext3" || fs_type == "ext2";
 }
 
+static bool is_f2fs(const std::string& fs_type) {
+    return fs_type == "f2fs";
+}
+
+static std::string realpath(const std::string& blk_device) {
+    std::string real_path;
+    if (!Realpath(blk_device, &real_path)) {
+        real_path = blk_device;
+    }
+    return real_path;
+}
+
 static bool should_force_check(int fs_stat) {
     return fs_stat &
            (FS_STAT_E2FSCK_F_ALWAYS | FS_STAT_UNCLEAN_SHUTDOWN | FS_STAT_QUOTA_ENABLED |
@@ -146,20 +168,21 @@
             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;
+    }
 
     /* Check for the types of filesystems we know how to check */
     if (is_extfs(fs_type)) {
-        if (*fs_stat & FS_STAT_EXT4_INVALID_MAGIC) {  // will fail, so do not try
-            return;
-        }
         /*
          * First try to mount and unmount the filesystem.  We do this because
          * the kernel is more efficient than e2fsck in running the journal and
@@ -175,18 +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;
@@ -209,10 +233,10 @@
          * (e.g. recent SDK system images). Detect these and skip the check.
          */
         if (access(E2FSCK_BIN, X_OK)) {
-            LINFO << "Not running " << E2FSCK_BIN << " on " << blk_device
+            LINFO << "Not running " << E2FSCK_BIN << " on " << realpath(blk_device)
                   << " (executable not in system image)";
         } else {
-            LINFO << "Running " << E2FSCK_BIN << " on " << blk_device;
+            LINFO << "Running " << E2FSCK_BIN << " on " << realpath(blk_device);
             if (should_force_check(*fs_stat)) {
                 ret = android_fork_execvp_ext(
                     ARRAY_SIZE(e2fsck_forced_argv), const_cast<char**>(e2fsck_forced_argv), &status,
@@ -232,13 +256,9 @@
                 *fs_stat |= FS_STAT_E2FSCK_FS_FIXED;
             }
         }
-    } else if (!strcmp(fs_type, "f2fs")) {
-            const char *f2fs_fsck_argv[] = {
-                    F2FS_FSCK_BIN,
-                    "-a",
-                    blk_device
-            };
-        LINFO << "Running " << F2FS_FSCK_BIN << " -a " << blk_device;
+    } else if (is_f2fs(fs_type)) {
+        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),
                                       const_cast<char **>(f2fs_fsck_argv),
@@ -272,9 +292,10 @@
 }
 
 // Read the primary superblock from an ext4 filesystem.  On failure return
-// false.  If it's not an ext4 filesystem, also set FS_STAT_EXT4_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)));
+// false.  If it's not an ext4 filesystem, also set FS_STAT_INVALID_MAGIC.
+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 << "'";
@@ -289,7 +310,7 @@
     if (!is_ext4_superblock_valid(sb)) {
         LINFO << "Invalid ext4 superblock on '" << blk_device << "'";
         // not a valid fs, tune2fs, fsck, and mount  will all fail.
-        *fs_stat |= FS_STAT_EXT4_INVALID_MAGIC;
+        *fs_stat |= FS_STAT_INVALID_MAGIC;
         return false;
     }
     *fs_stat |= FS_STAT_IS_EXT4;
@@ -315,7 +336,7 @@
 }
 
 // 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 struct fstab_rec* rec,
                        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;
@@ -330,7 +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;
@@ -351,7 +372,7 @@
 }
 
 // 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 struct fstab_rec* rec,
                                const struct ext4_super_block* sb, int* fs_stat) {
     if (!(rec->fs_mgr_flags & MF_RESERVEDSIZE)) {
         return;
@@ -383,7 +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;
@@ -392,7 +414,7 @@
 }
 
 // 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 struct fstab_rec* rec,
                          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;
@@ -407,7 +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))) {
@@ -417,6 +439,36 @@
     }
 }
 
+// Read the primary superblock from an f2fs filesystem.  On failure return
+// 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 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) {
+        PERROR << "Failed to open '" << blk_device << "'";
+        return false;
+    }
+
+    if (pread(fd, &sb1, sizeof(sb1), F2FS_SUPER_OFFSET) != sizeof(sb1)) {
+        PERROR << "Can't read '" << blk_device << "' superblock1";
+        return false;
+    }
+    if (pread(fd, &sb2, sizeof(sb2), F2FS_BLKSIZE + F2FS_SUPER_OFFSET) != sizeof(sb2)) {
+        PERROR << "Can't read '" << blk_device << "' superblock2";
+        return false;
+    }
+
+    if (sb1 != cpu_to_le32(F2FS_SUPER_MAGIC) && sb2 != cpu_to_le32(F2FS_SUPER_MAGIC)) {
+        LINFO << "Invalid f2fs superblock on '" << blk_device << "'";
+        *fs_stat |= FS_STAT_INVALID_MAGIC;
+        return false;
+    }
+    return true;
+}
+
 //
 // Prepare the filesystem on the given block device to be mounted.
 //
@@ -426,7 +478,7 @@
 // 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 struct fstab_rec* rec) {
     int fs_stat = 0;
 
     if (is_extfs(rec->fs_type)) {
@@ -446,6 +498,10 @@
         } else {
             return fs_stat;
         }
+    } else if (is_f2fs(rec->fs_type)) {
+        if (!read_f2fs_superblock(blk_device, &fs_stat)) {
+            return fs_stat;
+        }
     }
 
     if ((rec->fs_mgr_flags & MF_CHECK) ||
@@ -465,37 +521,15 @@
     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.
- * Return 0 on success, and -1 on error.
- */
-int fs_mgr_set_blk_ro(const char *blockdev)
-{
-    int fd;
-    int rc = -1;
-    int ON = 1;
-
-    fd = TEMP_FAILURE_RETRY(open(blockdev, O_RDONLY | O_CLOEXEC));
+// 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)));
     if (fd < 0) {
-        // should never happen
-        return rc;
+        return false;
     }
 
-    rc = ioctl(fd, BLKROSET, &ON);
-    close(fd);
-
-    return rc;
+    int ON = 1;
+    return ioctl(fd, BLKROSET, &ON) == 0;
 }
 
 // Orange state means the device is unlocked, see the following link for details.
@@ -508,34 +542,28 @@
     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 struct fstab_rec* rec) {
+    // 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 = rec->flags;
+    int ret = mount(source.c_str(), target.c_str(), rec->fs_type, mountflags, rec->fs_options);
+    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;
@@ -549,24 +577,32 @@
     return ret;
 }
 
-static int fs_match(const char *in1, const char *in2)
-{
-    char *n1;
-    char *n2;
-    int ret;
+static bool fs_match(const std::string& in1, const std::string& in2) {
+    if (in1.empty() || in2.empty()) {
+        return false;
+    }
 
-    n1 = strdup(in1);
-    n2 = strdup(in2);
+    auto in1_end = in1.size() - 1;
+    while (in1_end > 0 && in1[in1_end] == '/') {
+        in1_end--;
+    }
 
-    remove_trailing_slashes(n1);
-    remove_trailing_slashes(n2);
+    auto in2_end = in2.size() - 1;
+    while (in2_end > 0 && in2[in2_end] == '/') {
+        in2_end--;
+    }
 
-    ret = !strcmp(n1, n2);
+    if (in1_end != in2_end) {
+        return false;
+    }
 
-    free(n1);
-    free(n2);
+    for (size_t i = 0; i <= in1_end; ++i) {
+        if (in1[i] != in2[i]) {
+            return false;
+        }
+    }
 
-    return ret;
+    return true;
 }
 
 /*
@@ -612,9 +648,10 @@
             }
 
             int fs_stat = prepare_fs_for_mount(fstab->recs[i].blk_device, &fstab->recs[i]);
-            if (fs_stat & FS_STAT_EXT4_INVALID_MAGIC) {
-                LERROR << __FUNCTION__ << "(): skipping mount, invalid ext4, mountpoint="
-                       << fstab->recs[i].mount_point << " rec[" << 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;
@@ -662,82 +699,60 @@
     return 0;
 }
 
-static int translate_ext_labels(struct fstab_rec *rec)
-{
-    DIR *blockdir = NULL;
-    struct dirent *ent;
-    char *label;
-    size_t label_len;
-    int ret = -1;
-
-    if (strncmp(rec->blk_device, "LABEL=", 6))
-        return 0;
-
-    label = rec->blk_device + 6;
-    label_len = strlen(label);
-
-    if (label_len > 16) {
-        LERROR << "FS label is longer than allowed by filesystem";
-        goto out;
+static bool TranslateExtLabels(fstab_rec* rec) {
+    if (!StartsWith(rec->blk_device, "LABEL=")) {
+        return true;
     }
 
+    std::string label = rec->blk_device + 6;
+    if (label.size() > 16) {
+        LERROR << "FS label is longer than allowed by filesystem";
+        return false;
+    }
 
-    blockdir = opendir("/dev/block");
+    auto blockdir = std::unique_ptr<DIR, decltype(&closedir)>{opendir("/dev/block"), closedir};
     if (!blockdir) {
         LERROR << "couldn't open /dev/block";
-        goto out;
+        return false;
     }
 
-    while ((ent = readdir(blockdir))) {
-        int fd;
-        char super_buf[1024];
-        struct ext4_super_block *sb;
-
+    struct dirent* ent;
+    while ((ent = readdir(blockdir.get()))) {
         if (ent->d_type != DT_BLK)
             continue;
 
-        fd = openat(dirfd(blockdir), ent->d_name, O_RDONLY);
+        unique_fd fd(TEMP_FAILURE_RETRY(
+                openat(dirfd(blockdir.get()), ent->d_name, O_RDONLY | O_CLOEXEC)));
         if (fd < 0) {
             LERROR << "Cannot open block device /dev/block/" << ent->d_name;
-            goto out;
+            return false;
         }
 
+        ext4_super_block super_block;
         if (TEMP_FAILURE_RETRY(lseek(fd, 1024, SEEK_SET)) < 0 ||
-            TEMP_FAILURE_RETRY(read(fd, super_buf, 1024)) != 1024) {
-            /* Probably a loopback device or something else without a readable
-             * superblock.
-             */
-            close(fd);
+            TEMP_FAILURE_RETRY(read(fd, &super_block, sizeof(super_block))) !=
+                    sizeof(super_block)) {
+            // Probably a loopback device or something else without a readable superblock.
             continue;
         }
 
-        sb = (struct ext4_super_block *)super_buf;
-        if (sb->s_magic != EXT4_SUPER_MAGIC) {
+        if (super_block.s_magic != EXT4_SUPER_MAGIC) {
             LINFO << "/dev/block/" << ent->d_name << " not ext{234}";
             continue;
         }
 
-        if (!strncmp(label, sb->s_volume_name, label_len)) {
-            char *new_blk_device;
+        if (label == super_block.s_volume_name) {
+            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";
-                goto out;
-            }
-
-            LINFO << "resolved label " << rec->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;
-            ret = 0;
-            break;
+            rec->blk_device = strdup(new_blk_device.c_str());
+            return true;
         }
     }
 
-out:
-    closedir(blockdir);
-    return ret;
+    return false;
 }
 
 static bool needs_block_encryption(const struct fstab_rec* rec)
@@ -747,18 +762,14 @@
         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;
+        // Check for existence of convert_fde breadcrumb file.
+        auto convert_fde_name = rec->mount_point + "/misc/vold/convert_fde"s;
+        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;
+        // Check for absence of convert_fbe breadcrumb file.
+        auto convert_fbe_name = rec->mount_point + "/convert_fbe"s;
+        if (access(convert_fbe_name.c_str(), F_OK) != 0) return true;
     }
     return false;
 }
@@ -906,7 +917,7 @@
   private:
     bool UpdateCheckpointPartition(struct fstab_rec* rec) {
         if (fs_mgr_is_checkpoint_fs(rec)) {
-            if (!strcmp(rec->fs_type, "f2fs")) {
+            if (is_f2fs(rec->fs_type)) {
                 std::string opts(rec->fs_options);
 
                 opts += ",checkpoint=disable";
@@ -916,9 +927,8 @@
                 LERROR << rec->fs_type << " does not implement checkpoints.";
             }
         } else if (fs_mgr_is_checkpoint_blk(rec)) {
-            android::base::unique_fd fd(
-                    TEMP_FAILURE_RETRY(open(rec->blk_device, O_RDONLY | O_CLOEXEC)));
-            if (!fd) {
+            unique_fd fd(TEMP_FAILURE_RETRY(open(rec->blk_device, O_RDONLY | O_CLOEXEC)));
+            if (fd < 0) {
                 PERROR << "Cannot open device " << rec->blk_device;
                 return false;
             }
@@ -973,7 +983,7 @@
     int mount_errno = 0;
     int attempted_idx = -1;
     CheckpointManager checkpoint_manager;
-    FsManagerAvbUniquePtr avb_handle(nullptr);
+    AvbUniquePtr avb_handle(nullptr);
 
     if (!fstab) {
         return FS_MGR_MNTALL_FAIL;
@@ -982,8 +992,9 @@
     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]))) {
+            ((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])) {
             continue;
         }
 
@@ -997,7 +1008,7 @@
         /* 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].fs_mgr_flags & MS_RDONLY) != 0) {
+            if ((fstab->recs[i].flags & MS_RDONLY) != 0) {
                 fs_mgr_set_blk_ro(fstab->recs[i].blk_device);
             }
             continue;
@@ -1005,8 +1016,7 @@
 
         /* Translate LABEL= file system labels into block devices */
         if (is_extfs(fstab->recs[i].fs_type)) {
-            int tret = translate_ext_labels(&fstab->recs[i]);
-            if (tret < 0) {
+            if (!TranslateExtLabels(&fstab->recs[i])) {
                 LERROR << "Could not translate label to block device";
                 continue;
             }
@@ -1031,14 +1041,14 @@
 
         if (fstab->recs[i].fs_mgr_flags & MF_AVB) {
             if (!avb_handle) {
-                avb_handle = FsManagerAvbHandle::Open();
+                avb_handle = AvbHandle::Open();
                 if (!avb_handle) {
-                    LERROR << "Failed to open FsManagerAvbHandle";
+                    LERROR << "Failed to open AvbHandle";
                     return FS_MGR_MNTALL_FAIL;
                 }
             }
             if (avb_handle->SetUpAvbHashtree(&fstab->recs[i], true /* wait_for_verity_dev */) ==
-                SetUpAvbHashtreeResult::kFail) {
+                AvbHashtreeResult::kFail) {
                 LERROR << "Failed to set up AVB on partition: "
                        << fstab->recs[i].mount_point << ", skipping!";
                 /* Skips mounting the device. */
@@ -1099,21 +1109,20 @@
              * at two different lines in the fstab.  Use the top one for formatting
              * as that is the preferred one.
              */
-            LERROR << __FUNCTION__ << "(): " << 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.";
+            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.";
 
             checkpoint_manager.Revert(&fstab->recs[top_idx]);
 
             if (fs_mgr_is_encryptable(&fstab->recs[top_idx]) &&
                 strcmp(fstab->recs[top_idx].key_loc, KEY_IN_FOOTER)) {
-                int fd = open(fstab->recs[top_idx].key_loc, O_WRONLY);
+                unique_fd fd(TEMP_FAILURE_RETRY(
+                        open(fstab->recs[top_idx].key_loc, O_WRONLY | O_CLOEXEC)));
                 if (fd >= 0) {
                     LINFO << __FUNCTION__ << "(): also wipe "
                           << fstab->recs[top_idx].key_loc;
                     wipe_block_device(fd, get_file_size(fd));
-                    close(fd);
                 } else {
                     PERROR << __FUNCTION__ << "(): "
                            << fstab->recs[top_idx].key_loc << " wouldn't open";
@@ -1232,7 +1241,7 @@
     int first_mount_errno = 0;
     char* mount_point;
     CheckpointManager checkpoint_manager(needs_checkpoint);
-    FsManagerAvbUniquePtr avb_handle(nullptr);
+    AvbUniquePtr avb_handle(nullptr);
 
     if (!fstab) {
         return FS_MGR_DOMNT_FAILED;
@@ -1275,14 +1284,14 @@
 
         if (fstab->recs[i].fs_mgr_flags & MF_AVB) {
             if (!avb_handle) {
-                avb_handle = FsManagerAvbHandle::Open();
+                avb_handle = AvbHandle::Open();
                 if (!avb_handle) {
-                    LERROR << "Failed to open FsManagerAvbHandle";
+                    LERROR << "Failed to open AvbHandle";
                     return FS_MGR_DOMNT_FAILED;
                 }
             }
             if (avb_handle->SetUpAvbHashtree(&fstab->recs[i], true /* wait_for_verity_dev */) ==
-                SetUpAvbHashtreeResult::kFail) {
+                AvbHashtreeResult::kFail) {
                 LERROR << "Failed to set up AVB on partition: "
                        << fstab->recs[i].mount_point << ", skipping!";
                 /* Skips mounting the device. */
@@ -1362,89 +1371,74 @@
     return 0;
 }
 
-/* This must be called after mount_all, because the mkswap command needs to be
- * available.
- */
-int fs_mgr_swapon_all(fstab* fstab) {
-    int i = 0;
-    int flags = 0;
-    int err = 0;
-    int ret = 0;
-    int status;
-    const char *mkswap_argv[2] = {
-        MKSWAP_BIN,
-        nullptr
-    };
-
-    if (!fstab) {
-        return -1;
-    }
-
-    for (i = 0; i < fstab->num_entries; i++) {
-        /* Skip non-swap entries */
-        if (strcmp(fstab->recs[i].fs_type, "swap")) {
+bool fs_mgr_swapon_all(const Fstab& fstab) {
+    bool ret = true;
+    for (const auto& entry : fstab) {
+        // Skip non-swap entries.
+        if (entry.fs_type != "swap") {
             continue;
         }
 
-        if (fstab->recs[i].zram_size > 0) {
-            /* A zram_size was specified, so we need to configure the
-             * device.  There is no point in having multiple zram devices
-             * on a system (all the memory comes from the same pool) so
-             * we can assume the device number is 0.
-             */
-            if (fstab->recs[i].max_comp_streams >= 0) {
+        if (entry.zram_size > 0) {
+            // A zram_size was specified, so we need to configure the
+            // device.  There is no point in having multiple zram devices
+            // on a system (all the memory comes from the same pool) so
+            // we can assume the device number is 0.
+            if (entry.max_comp_streams >= 0) {
                 auto zram_mcs_fp = std::unique_ptr<FILE, decltype(&fclose)>{
                         fopen(ZRAM_CONF_MCS, "re"), fclose};
-                if (zram_mcs_fp == NULL) {
+                if (zram_mcs_fp == nullptr) {
                     LERROR << "Unable to open zram conf comp device " << ZRAM_CONF_MCS;
-                    ret = -1;
+                    ret = false;
                     continue;
                 }
-                fprintf(zram_mcs_fp.get(), "%d\n", fstab->recs[i].max_comp_streams);
+                fprintf(zram_mcs_fp.get(), "%d\n", entry.max_comp_streams);
             }
 
             auto zram_fp =
                     std::unique_ptr<FILE, decltype(&fclose)>{fopen(ZRAM_CONF_DEV, "re+"), fclose};
-            if (zram_fp == NULL) {
+            if (zram_fp == nullptr) {
                 LERROR << "Unable to open zram conf device " << ZRAM_CONF_DEV;
-                ret = -1;
+                ret = false;
                 continue;
             }
-            fprintf(zram_fp.get(), "%u\n", fstab->recs[i].zram_size);
+            fprintf(zram_fp.get(), "%" PRId64 "\n", entry.zram_size);
         }
 
-        if (fstab->recs[i].fs_mgr_flags & MF_WAIT &&
-            !fs_mgr_wait_for_file(fstab->recs[i].blk_device, 20s)) {
-            LERROR << "Skipping mkswap for '" << fstab->recs[i].blk_device << "'";
-            ret = -1;
+        if (entry.fs_mgr_flags.wait && !fs_mgr_wait_for_file(entry.blk_device, 20s)) {
+            LERROR << "Skipping mkswap for '" << entry.blk_device << "'";
+            ret = false;
             continue;
         }
 
-        /* Initialize the swap area */
-        mkswap_argv[1] = fstab->recs[i].blk_device;
-        err = android_fork_execvp_ext(ARRAY_SIZE(mkswap_argv),
-                                      const_cast<char **>(mkswap_argv),
-                                      &status, true, LOG_KLOG, false, NULL,
-                                      NULL, 0);
+        // Initialize the swap area.
+        const char* mkswap_argv[2] = {
+                MKSWAP_BIN,
+                entry.blk_device.c_str(),
+        };
+        int err = 0;
+        int status;
+        err = android_fork_execvp_ext(ARRAY_SIZE(mkswap_argv), const_cast<char**>(mkswap_argv),
+                                      &status, true, LOG_KLOG, false, nullptr, nullptr, 0);
         if (err) {
-            LERROR << "mkswap failed for " << fstab->recs[i].blk_device;
-            ret = -1;
+            LERROR << "mkswap failed for " << entry.blk_device;
+            ret = false;
             continue;
         }
 
         /* If -1, then no priority was specified in fstab, so don't set
          * SWAP_FLAG_PREFER or encode the priority */
-        if (fstab->recs[i].swap_prio >= 0) {
-            flags = (fstab->recs[i].swap_prio << SWAP_FLAG_PRIO_SHIFT) &
-                    SWAP_FLAG_PRIO_MASK;
+        int flags = 0;
+        if (entry.swap_prio >= 0) {
+            flags = (entry.swap_prio << SWAP_FLAG_PRIO_SHIFT) & SWAP_FLAG_PRIO_MASK;
             flags |= SWAP_FLAG_PREFER;
         } else {
             flags = 0;
         }
-        err = swapon(fstab->recs[i].blk_device, flags);
+        err = swapon(entry.blk_device.c_str(), flags);
         if (err) {
-            LERROR << "swapon failed for " << fstab->recs[i].blk_device;
-            ret = -1;
+            LERROR << "swapon failed for " << entry.blk_device;
+            ret = false;
         }
     }
 
@@ -1526,7 +1520,8 @@
     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;
     }
@@ -1536,27 +1531,25 @@
         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) {
@@ -1567,7 +1560,7 @@
         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;
             }
@@ -1581,7 +1574,7 @@
         // 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);
         }
     }
 
@@ -1603,9 +1596,6 @@
         } else if (slot == -1) {
             suffix = fs_mgr_get_slot_suffix();
         }
-        if (suffix.empty()) {
-            LFATAL << "Super partition name can only be overridden on A/B devices.";
-        }
         return super_partition + suffix;
     }
     return LP_METADATA_DEFAULT_PARTITION_NAME;
diff --git a/fs_mgr/fs_mgr_dm_linear.cpp b/fs_mgr/fs_mgr_dm_linear.cpp
index fe0e039..3f075ef 100644
--- a/fs_mgr/fs_mgr_dm_linear.cpp
+++ b/fs_mgr/fs_mgr_dm_linear.cpp
@@ -51,12 +51,20 @@
 using DmTargetZero = android::dm::DmTargetZero;
 using DmTargetLinear = android::dm::DmTargetLinear;
 
-bool GetPhysicalPartitionDevicePath(const LpMetadataBlockDevice& block_device,
-                                    std::string* result) {
+static bool GetPhysicalPartitionDevicePath(const LpMetadata& metadata,
+                                           const LpMetadataBlockDevice& block_device,
+                                           const std::string& super_device,
+                                           std::string* result) {
     // Note: device-mapper will not accept symlinks, so we must use realpath
     // here.
     std::string name = GetBlockDevicePartitionName(block_device);
     std::string path = "/dev/block/by-name/" + name;
+    // If the super device is the source of this block device's metadata,
+    // make sure we use the correct super device (and not just "super",
+    // which might not exist.)
+    if (GetMetadataSuperBlockDevice(metadata) == &block_device) {
+        path = super_device;
+    }
     if (!android::base::Realpath(path, result)) {
         PERROR << "realpath: " << path;
         return false;
@@ -65,7 +73,7 @@
 }
 
 static bool CreateDmTable(const LpMetadata& metadata, const LpMetadataPartition& partition,
-                          DmTable* table) {
+                          const std::string& super_device, DmTable* table) {
     uint64_t sector = 0;
     for (size_t i = 0; i < partition.num_extents; i++) {
         const auto& extent = metadata.extents[partition.first_extent_index + i];
@@ -77,7 +85,7 @@
             case LP_TARGET_TYPE_LINEAR: {
                 const auto& block_device = metadata.block_devices[extent.target_source];
                 std::string path;
-                if (!GetPhysicalPartitionDevicePath(block_device, &path)) {
+                if (!GetPhysicalPartitionDevicePath(metadata, block_device, super_device, &path)) {
                     LOG(ERROR) << "Unable to complete device-mapper table, unknown block device";
                     return false;
                 }
@@ -102,11 +110,11 @@
 
 static bool CreateLogicalPartition(const LpMetadata& metadata, const LpMetadataPartition& partition,
                                    bool force_writable, const std::chrono::milliseconds& timeout_ms,
-                                   std::string* path) {
+                                   const std::string& super_device, std::string* path) {
     DeviceMapper& dm = DeviceMapper::Instance();
 
     DmTable table;
-    if (!CreateDmTable(metadata, partition, &table)) {
+    if (!CreateDmTable(metadata, partition, super_device, &table)) {
         return false;
     }
     if (force_writable) {
@@ -137,7 +145,7 @@
         LOG(ERROR) << "Could not read partition table.";
         return true;
     }
-    return CreateLogicalPartitions(*metadata.get());
+    return CreateLogicalPartitions(*metadata.get(), block_device);
 }
 
 std::unique_ptr<LpMetadata> ReadCurrentMetadata(const std::string& block_device) {
@@ -145,14 +153,14 @@
     return ReadMetadata(block_device.c_str(), slot);
 }
 
-bool CreateLogicalPartitions(const LpMetadata& metadata) {
+bool CreateLogicalPartitions(const LpMetadata& metadata, const std::string& super_device) {
     for (const auto& partition : metadata.partitions) {
         if (!partition.num_extents) {
             LINFO << "Skipping zero-length logical partition: " << GetPartitionName(partition);
             continue;
         }
         std::string path;
-        if (!CreateLogicalPartition(metadata, partition, false, {}, &path)) {
+        if (!CreateLogicalPartition(metadata, partition, false, {}, super_device, &path)) {
             LERROR << "Could not create logical partition: " << GetPartitionName(partition);
             return false;
         }
@@ -171,7 +179,7 @@
     for (const auto& partition : metadata->partitions) {
         if (GetPartitionName(partition) == partition_name) {
             return CreateLogicalPartition(*metadata.get(), partition, force_writable, timeout_ms,
-                                          path);
+                                          block_device, path);
         }
     }
     LERROR << "Could not find any partition with name: " << partition_name;
diff --git a/fs_mgr/fs_mgr_format.cpp b/fs_mgr/fs_mgr_format.cpp
index 845cca9..737deca 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) {
@@ -117,13 +109,8 @@
     // clang-format off
     const char* const args[] = {
         "/system/bin/make_f2fs",
-        "-d1",
-        "-f",
-        "-O", "encrypt",
-        "-O", "quota",
-        "-O", "verity",
-        "-w", "4096",
-        fs_blkdev,
+        "-g", "android",
+        fs_blkdev.c_str(),
         size_str.c_str(),
         nullptr
     };
diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index e89c91c..0fde22e 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -38,21 +38,21 @@
 const std::string kDefaultAndroidDtDir("/proc/device-tree/firmware/android");
 
 struct fs_mgr_flag_values {
-    char *key_loc;
-    char* key_dir;
-    char *verity_loc;
-    char *sysfs_path;
-    long long part_length;
-    char *label;
-    int partnum;
-    int swap_prio;
-    int max_comp_streams;
-    unsigned int zram_size;
-    uint64_t reserved_size;
-    unsigned int file_contents_mode;
-    unsigned int file_names_mode;
-    unsigned int erase_blk_size;
-    unsigned int logical_blk_size;
+    std::string key_loc;
+    std::string key_dir;
+    std::string verity_loc;
+    std::string sysfs_path;
+    off64_t part_length = 0;
+    std::string label;
+    int partnum = -1;
+    int swap_prio = -1;
+    int max_comp_streams = 0;
+    off64_t zram_size = 0;
+    off64_t reserved_size = 0;
+    int file_contents_mode = 0;
+    int file_names_mode = 0;
+    off64_t erase_blk_size = 0;
+    off64_t logical_blk_size = 0;
 };
 
 struct flag_list {
@@ -102,6 +102,7 @@
         {"formattable", MF_FORMATTABLE},
         {"slotselect", MF_SLOTSELECT},
         {"nofail", MF_NOFAIL},
+        {"first_stage_mount", MF_FIRST_STAGE_MOUNT},
         {"latemount", MF_LATEMOUNT},
         {"reservedsize=", MF_RESERVEDSIZE},
         {"quota", MF_QUOTA},
@@ -133,9 +134,8 @@
     {0, 0},
 };
 
-static unsigned int encryption_mode_to_flag(const struct flag_list *list,
-                                            const char *mode, const char *type)
-{
+static int encryption_mode_to_flag(const struct flag_list* list, const char* mode,
+                                   const char* type) {
     const struct flag_list *j;
 
     for (j = list; j->name; ++j) {
@@ -147,9 +147,7 @@
     return 0;
 }
 
-static const char *flag_to_encryption_mode(const struct flag_list *list,
-                                           unsigned int flag)
-{
+static const char* flag_to_encryption_mode(const struct flag_list* list, int flag) {
     const struct flag_list *j;
 
     for (j = list; j->name; ++j) {
@@ -160,9 +158,8 @@
     return nullptr;
 }
 
-static uint64_t calculate_zram_size(unsigned int percentage)
-{
-    uint64_t total;
+static off64_t calculate_zram_size(unsigned int percentage) {
+    off64_t total;
 
     total  = sysconf(_SC_PHYS_PAGES);
     total *= percentage;
@@ -173,10 +170,9 @@
     return total;
 }
 
-static uint64_t parse_size(const char *arg)
-{
+static off64_t parse_size(const char* arg) {
     char *endptr;
-    uint64_t size = strtoull(arg, &endptr, 10);
+    off64_t size = strtoll(arg, &endptr, 10);
     if (*endptr == 'k' || *endptr == 'K')
         size *= 1024LL;
     else if (*endptr == 'm' || *endptr == 'M')
@@ -214,14 +210,6 @@
     char *p;
     char *savep;
 
-    /* initialize flag values.  If we find a relevant flag, we'll
-     * update the value */
-    if (flag_vals) {
-        memset(flag_vals, 0, sizeof(*flag_vals));
-        flag_vals->partnum = -1;
-        flag_vals->swap_prio = -1; /* negative means it wasn't specified. */
-    }
-
     /* initialize fs_options to the null string */
     if (fs_options && (fs_options_len > 0)) {
         fs_options[0] = '\0';
@@ -247,22 +235,22 @@
                     /* The encryptable flag is followed by an = and the
                      * location of the keys.  Get it and return it.
                      */
-                    flag_vals->key_loc = strdup(arg);
+                    flag_vals->key_loc = arg;
                 } else if (flag == MF_VERIFY) {
                     /* If the verify flag is followed by an = and the
                      * location for the verity state,  get it and return it.
                      */
-                    flag_vals->verity_loc = strdup(arg);
+                    flag_vals->verity_loc = arg;
                 } else if (flag == MF_FORCECRYPT) {
                     /* The forceencrypt flag is followed by an = and the
                      * location of the keys.  Get it and return it.
                      */
-                    flag_vals->key_loc = strdup(arg);
+                    flag_vals->key_loc = arg;
                 } else if (flag == MF_FORCEFDEORFBE) {
                     /* The forcefdeorfbe flag is followed by an = and the
                      * location of the keys.  Get it and return it.
                      */
-                    flag_vals->key_loc = strdup(arg);
+                    flag_vals->key_loc = arg;
                     flag_vals->file_contents_mode = EM_AES_256_XTS;
                     flag_vals->file_names_mode = EM_AES_256_CTS;
                 } else if (flag == MF_FILEENCRYPTION) {
@@ -290,7 +278,7 @@
                     /* The metadata flag is followed by an = and the
                      * directory for the keys.  Get it and return it.
                      */
-                    flag_vals->key_dir = strdup(arg);
+                    flag_vals->key_dir = arg;
                 } else if (flag == MF_LENGTH) {
                     /* The length flag is followed by an = and the
                      * size of the partition.  Get it and return it.
@@ -307,8 +295,7 @@
                     auto label_end = strchr(label_start, ':');
 
                     if (label_end) {
-                        flag_vals->label = strndup(label_start,
-                                                   (int) (label_end - label_start));
+                        flag_vals->label = std::string(label_start, (int)(label_end - label_start));
                         auto part_start = label_end + 1;
                         if (!strcmp(part_start, "auto")) {
                             flag_vals->partnum = -1;
@@ -339,7 +326,7 @@
                      * erase block size. Get it, check that it is a power of 2 and
                      * at least 4096, and return it.
                      */
-                    auto val = strtoul(arg, NULL, 0);
+                    auto val = strtoll(arg, nullptr, 0);
                     if (val >= 4096 && (val & (val - 1)) == 0)
                         flag_vals->erase_blk_size = val;
                 } else if (flag == MF_LOGICALBLKSIZE) {
@@ -347,12 +334,12 @@
                      * logical block size. Get it, check that it is a power of 2 and
                      * at least 4096, and return it.
                      */
-                    auto val = strtoul(arg, NULL, 0);
+                    auto val = strtoll(arg, nullptr, 0);
                     if (val >= 4096 && (val & (val - 1)) == 0)
                         flag_vals->logical_blk_size = val;
                 } else if (flag == MF_SYSFS) {
                     /* The path to trigger device gc by idle-maint of vold. */
-                    flag_vals->sysfs_path = strdup(arg);
+                    flag_vals->sysfs_path = arg;
                 }
                 break;
             }
@@ -509,49 +496,17 @@
     return false;
 }
 
-static struct fstab* fs_mgr_read_fstab_file(FILE* fstab_file, bool proc_mounts) {
-    int cnt, entries;
+static bool fs_mgr_read_fstab_file(FILE* fstab_file, bool proc_mounts, Fstab* fstab_out) {
     ssize_t len;
     size_t alloc_len = 0;
     char *line = NULL;
     const char *delim = " \t";
     char *save_ptr, *p;
-    struct fstab *fstab = NULL;
+    Fstab fstab;
     struct fs_mgr_flag_values flag_vals;
 #define FS_OPTIONS_LEN 1024
     char tmp_fs_options[FS_OPTIONS_LEN];
 
-    entries = 0;
-    while ((len = getline(&line, &alloc_len, fstab_file)) != -1) {
-        /* if the last character is a newline, shorten the string by 1 byte */
-        if (line[len - 1] == '\n') {
-            line[len - 1] = '\0';
-        }
-        /* Skip any leading whitespace */
-        p = line;
-        while (isspace(*p)) {
-            p++;
-        }
-        /* ignore comments or empty lines */
-        if (*p == '#' || *p == '\0')
-            continue;
-        entries++;
-    }
-
-    if (!entries) {
-        LERROR << "No entries found in fstab";
-        goto err;
-    }
-
-    /* Allocate and init the fstab structure */
-    fstab = static_cast<struct fstab *>(calloc(1, sizeof(struct fstab)));
-    fstab->num_entries = entries;
-    fstab->recs = static_cast<struct fstab_rec *>(
-        calloc(fstab->num_entries, sizeof(struct fstab_rec)));
-
-    fseek(fstab_file, 0, SEEK_SET);
-
-    cnt = 0;
     while ((len = getline(&line, &alloc_len, fstab_file)) != -1) {
         /* if the last character is a newline, shorten the string by 1 byte */
         if (line[len - 1] == '\n') {
@@ -567,46 +522,36 @@
         if (*p == '#' || *p == '\0')
             continue;
 
-        /* If a non-comment entry is greater than the size we allocated, give an
-         * error and quit.  This can happen in the unlikely case the file changes
-         * between the two reads.
-         */
-        if (cnt >= entries) {
-            LERROR << "Tried to process more entries than counted";
-            break;
-        }
+        FstabEntry entry;
 
         if (!(p = strtok_r(line, delim, &save_ptr))) {
             LERROR << "Error parsing mount source";
             goto err;
         }
-        fstab->recs[cnt].blk_device = strdup(p);
+        entry.blk_device = p;
 
         if (!(p = strtok_r(NULL, delim, &save_ptr))) {
             LERROR << "Error parsing mount_point";
             goto err;
         }
-        fstab->recs[cnt].mount_point = strdup(p);
+        entry.mount_point = p;
 
         if (!(p = strtok_r(NULL, delim, &save_ptr))) {
             LERROR << "Error parsing fs_type";
             goto err;
         }
-        fstab->recs[cnt].fs_type = strdup(p);
+        entry.fs_type = p;
 
         if (!(p = strtok_r(NULL, delim, &save_ptr))) {
             LERROR << "Error parsing mount_flags";
             goto err;
         }
         tmp_fs_options[0] = '\0';
-        fstab->recs[cnt].flags = parse_flags(p, mount_flags, NULL,
-                                       tmp_fs_options, FS_OPTIONS_LEN);
+        entry.flags = parse_flags(p, mount_flags, NULL, tmp_fs_options, FS_OPTIONS_LEN);
 
         /* fs_options are optional */
         if (tmp_fs_options[0]) {
-            fstab->recs[cnt].fs_options = strdup(tmp_fs_options);
-        } else {
-            fstab->recs[cnt].fs_options = NULL;
+            entry.fs_options = tmp_fs_options;
         }
 
         // For /proc/mounts, ignore everything after mnt_freq and mnt_passno
@@ -616,78 +561,47 @@
             LERROR << "Error parsing fs_mgr_options";
             goto err;
         }
-        fstab->recs[cnt].fs_mgr_flags = parse_flags(p, fs_mgr_flags,
-                                                    &flag_vals, NULL, 0);
-        fstab->recs[cnt].key_loc = flag_vals.key_loc;
-        fstab->recs[cnt].key_dir = flag_vals.key_dir;
-        fstab->recs[cnt].verity_loc = flag_vals.verity_loc;
-        fstab->recs[cnt].length = flag_vals.part_length;
-        fstab->recs[cnt].label = flag_vals.label;
-        fstab->recs[cnt].partnum = flag_vals.partnum;
-        fstab->recs[cnt].swap_prio = flag_vals.swap_prio;
-        fstab->recs[cnt].max_comp_streams = flag_vals.max_comp_streams;
-        fstab->recs[cnt].zram_size = flag_vals.zram_size;
-        fstab->recs[cnt].reserved_size = flag_vals.reserved_size;
-        fstab->recs[cnt].file_contents_mode = flag_vals.file_contents_mode;
-        fstab->recs[cnt].file_names_mode = flag_vals.file_names_mode;
-        fstab->recs[cnt].erase_blk_size = flag_vals.erase_blk_size;
-        fstab->recs[cnt].logical_blk_size = flag_vals.logical_blk_size;
-        fstab->recs[cnt].sysfs_path = flag_vals.sysfs_path;
-        if (fstab->recs[cnt].fs_mgr_flags & MF_LOGICAL) {
-            fstab->recs[cnt].logical_partition_name = strdup(fstab->recs[cnt].blk_device);
+        entry.fs_mgr_flags.val = parse_flags(p, fs_mgr_flags, &flag_vals, NULL, 0);
+
+        entry.key_loc = std::move(flag_vals.key_loc);
+        entry.key_dir = std::move(flag_vals.key_dir);
+        entry.verity_loc = std::move(flag_vals.verity_loc);
+        entry.length = flag_vals.part_length;
+        entry.label = std::move(flag_vals.label);
+        entry.partnum = flag_vals.partnum;
+        entry.swap_prio = flag_vals.swap_prio;
+        entry.max_comp_streams = flag_vals.max_comp_streams;
+        entry.zram_size = flag_vals.zram_size;
+        entry.reserved_size = flag_vals.reserved_size;
+        entry.file_contents_mode = flag_vals.file_contents_mode;
+        entry.file_names_mode = flag_vals.file_names_mode;
+        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);
+        if (entry.fs_mgr_flags.logical) {
+            entry.logical_partition_name = entry.blk_device;
         }
 
-        cnt++;
+        fstab.emplace_back(std::move(entry));
     }
+
+    if (fstab.empty()) {
+        LERROR << "No entries found in fstab";
+        goto err;
+    }
+
     /* If an A/B partition, modify block device to be the real block device */
-    if (!fs_mgr_update_for_slotselect(fstab)) {
+    if (!fs_mgr_update_for_slotselect(&fstab)) {
         LERROR << "Error updating for slotselect";
         goto err;
     }
     free(line);
-    return fstab;
+    *fstab_out = std::move(fstab);
+    return true;
 
 err:
     free(line);
-    if (fstab)
-        fs_mgr_free_fstab(fstab);
-    return NULL;
-}
-
-/* merges fstab entries from both a and b, then returns the merged result.
- * note that the caller should only manage the return pointer without
- * doing further memory management for the two inputs, i.e. only need to
- * frees up memory of the return value without touching a and b. */
-static struct fstab *in_place_merge(struct fstab *a, struct fstab *b)
-{
-    if (!a && !b) return nullptr;
-    if (!a) return b;
-    if (!b) return a;
-
-    int total_entries = a->num_entries + b->num_entries;
-    a->recs = static_cast<struct fstab_rec *>(realloc(
-        a->recs, total_entries * (sizeof(struct fstab_rec))));
-    if (!a->recs) {
-        LERROR << __FUNCTION__ << "(): failed to allocate fstab recs";
-        // If realloc() fails the original block is left untouched;
-        // it is not freed or moved. So we have to free both a and b here.
-        fs_mgr_free_fstab(a);
-        fs_mgr_free_fstab(b);
-        return nullptr;
-    }
-
-    for (int i = a->num_entries, j = 0; i < total_entries; i++, j++) {
-        // Copy the structs by assignment.
-        a->recs[i] = b->recs[j];
-    }
-
-    // We can't call fs_mgr_free_fstab because a->recs still references the
-    // memory allocated by strdup.
-    free(b->recs);
-    free(b);
-
-    a->num_entries = total_entries;
-    return a;
+    return false;
 }
 
 /* Extracts <device>s from the by-name symlinks specified in a fstab:
@@ -700,11 +614,11 @@
  *   /dev/block/pci/soc.0/f9824900.sdhci/by-name/vendor
  * it returns a set { "soc/1da4000.ufshc", "soc.0/f9824900.sdhci" }.
  */
-static std::set<std::string> extract_boot_devices(const fstab& fstab) {
+static std::set<std::string> extract_boot_devices(const Fstab& fstab) {
     std::set<std::string> boot_devices;
 
-    for (int i = 0; i < fstab.num_entries; i++) {
-        std::string blk_device(fstab.recs[i].blk_device);
+    for (const auto& entry : fstab) {
+        std::string blk_device = entry.blk_device;
         // Skips blk_device that doesn't conform to the format.
         if (!android::base::StartsWith(blk_device, "/dev/block") ||
             android::base::StartsWith(blk_device, "/dev/block/by-name") ||
@@ -733,33 +647,36 @@
     return boot_devices;
 }
 
-struct fstab *fs_mgr_read_fstab(const char *fstab_path)
-{
-    struct fstab *fstab;
-
-    auto fstab_file = std::unique_ptr<FILE, decltype(&fclose)>{fopen(fstab_path, "re"), fclose};
+bool ReadFstabFromFile(const std::string& path, Fstab* fstab) {
+    auto fstab_file = std::unique_ptr<FILE, decltype(&fclose)>{fopen(path.c_str(), "re"), fclose};
     if (!fstab_file) {
-        PERROR << __FUNCTION__<< "(): cannot open file: '" << fstab_path << "'";
+        PERROR << __FUNCTION__ << "(): cannot open file: '" << path << "'";
+        return false;
+    }
+
+    if (!fs_mgr_read_fstab_file(fstab_file.get(), path == "/proc/mounts", fstab)) {
+        LERROR << __FUNCTION__ << "(): failed to load fstab from : '" << path << "'";
+        return false;
+    }
+
+    return true;
+}
+
+struct fstab* fs_mgr_read_fstab(const char* fstab_path) {
+    Fstab fstab;
+    if (!ReadFstabFromFile(fstab_path, &fstab)) {
         return nullptr;
     }
 
-    fstab = fs_mgr_read_fstab_file(fstab_file.get(), !strcmp("/proc/mounts", fstab_path));
-    if (!fstab) {
-        LERROR << __FUNCTION__ << "(): failed to load fstab from : '" << fstab_path << "'";
-    }
-
-    return fstab;
+    return FstabToLegacyFstab(fstab);
 }
 
-/* Returns fstab entries parsed from the device tree if they
- * exist
- */
-struct fstab *fs_mgr_read_fstab_dt()
-{
+// Returns fstab entries parsed from the device tree if they exist
+bool ReadFstabFromDt(Fstab* fstab) {
     std::string fstab_buf = read_fstab_from_dt();
     if (fstab_buf.empty()) {
         LINFO << __FUNCTION__ << "(): failed to read fstab from dt";
-        return nullptr;
+        return false;
     }
 
     std::unique_ptr<FILE, decltype(&fclose)> fstab_file(
@@ -767,16 +684,25 @@
                  fstab_buf.length(), "r"), fclose);
     if (!fstab_file) {
         PERROR << __FUNCTION__ << "(): failed to create a file stream for fstab dt";
+        return false;
+    }
+
+    if (!fs_mgr_read_fstab_file(fstab_file.get(), false, fstab)) {
+        LERROR << __FUNCTION__ << "(): failed to load fstab from kernel:"
+               << std::endl << fstab_buf;
+        return false;
+    }
+
+    return true;
+}
+
+struct fstab* fs_mgr_read_fstab_dt() {
+    Fstab fstab;
+    if (!ReadFstabFromDt(&fstab)) {
         return nullptr;
     }
 
-    struct fstab* fstab = fs_mgr_read_fstab_file(fstab_file.get(), false);
-    if (!fstab) {
-        LERROR << __FUNCTION__ << "(): failed to load fstab from kernel:"
-               << std::endl << fstab_buf;
-    }
-
-    return fstab;
+    return FstabToLegacyFstab(fstab);
 }
 
 /*
@@ -802,32 +728,42 @@
     return std::string();
 }
 
-/*
- * loads the fstab file and combines with fstab entries passed in from device tree.
- */
-struct fstab *fs_mgr_read_fstab_default()
-{
-    std::string default_fstab;
+// Loads the fstab file and combines with fstab entries passed in from device tree.
+bool ReadDefaultFstab(Fstab* fstab) {
+    Fstab dt_fstab;
+    ReadFstabFromDt(&dt_fstab);
 
+    *fstab = std::move(dt_fstab);
+
+    std::string default_fstab_path;
     // Use different fstab paths for normal boot and recovery boot, respectively
     if (access("/system/bin/recovery", F_OK) == 0) {
-        default_fstab = "/etc/recovery.fstab";
+        default_fstab_path = "/etc/recovery.fstab";
     } else {  // normal boot
-        default_fstab = get_fstab_path();
+        default_fstab_path = get_fstab_path();
     }
 
-    struct fstab* fstab = nullptr;
-    if (!default_fstab.empty()) {
-        fstab = fs_mgr_read_fstab(default_fstab.c_str());
+    Fstab default_fstab;
+    if (!default_fstab_path.empty()) {
+        ReadFstabFromFile(default_fstab_path, &default_fstab);
     } else {
         LINFO << __FUNCTION__ << "(): failed to find device default fstab";
     }
 
-    struct fstab* fstab_dt = fs_mgr_read_fstab_dt();
+    for (auto&& entry : default_fstab) {
+        fstab->emplace_back(std::move(entry));
+    }
 
-    // combines fstab entries passed in from device tree with
-    // the ones found from default_fstab file
-    return in_place_merge(fstab_dt, fstab);
+    return !fstab->empty();
+}
+
+struct fstab* fs_mgr_read_fstab_default() {
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
+        return nullptr;
+    }
+
+    return FstabToLegacyFstab(fstab);
 }
 
 void fs_mgr_free_fstab(struct fstab *fstab)
@@ -913,11 +849,83 @@
     }
 
     // Fallback to extract boot devices from fstab.
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab(fs_mgr_read_fstab_default(),
-                                                               fs_mgr_free_fstab);
-    if (fstab) return extract_boot_devices(*fstab);
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
+        return {};
+    }
 
-    return {};
+    return extract_boot_devices(fstab);
+}
+
+FstabEntry FstabRecToFstabEntry(const fstab_rec* fstab_rec) {
+    FstabEntry entry;
+    entry.blk_device = fstab_rec->blk_device;
+    entry.logical_partition_name = fstab_rec->logical_partition_name;
+    entry.mount_point = fstab_rec->mount_point;
+    entry.fs_type = fstab_rec->fs_type;
+    entry.flags = fstab_rec->flags;
+    entry.fs_options = fstab_rec->fs_options;
+    entry.fs_mgr_flags.val = fstab_rec->fs_mgr_flags;
+    entry.key_loc = fstab_rec->key_loc;
+    entry.key_dir = fstab_rec->key_dir;
+    entry.verity_loc = fstab_rec->verity_loc;
+    entry.length = fstab_rec->length;
+    entry.label = fstab_rec->label;
+    entry.partnum = fstab_rec->partnum;
+    entry.swap_prio = fstab_rec->swap_prio;
+    entry.max_comp_streams = fstab_rec->max_comp_streams;
+    entry.zram_size = fstab_rec->zram_size;
+    entry.reserved_size = fstab_rec->reserved_size;
+    entry.file_contents_mode = fstab_rec->file_contents_mode;
+    entry.file_names_mode = fstab_rec->file_names_mode;
+    entry.erase_blk_size = fstab_rec->erase_blk_size;
+    entry.logical_blk_size = fstab_rec->logical_blk_size;
+    entry.sysfs_path = fstab_rec->sysfs_path;
+
+    return entry;
+}
+
+Fstab LegacyFstabToFstab(const struct fstab* legacy_fstab) {
+    Fstab fstab;
+    for (int i = 0; i < legacy_fstab->num_entries; i++) {
+        fstab.emplace_back(FstabRecToFstabEntry(&legacy_fstab->recs[i]));
+    }
+
+    return fstab;
+}
+
+fstab* FstabToLegacyFstab(const Fstab& fstab) {
+    struct fstab* legacy_fstab = static_cast<struct fstab*>(calloc(1, sizeof(struct fstab)));
+    legacy_fstab->num_entries = fstab.size();
+    legacy_fstab->recs =
+            static_cast<fstab_rec*>(calloc(legacy_fstab->num_entries, sizeof(fstab_rec)));
+
+    for (int i = 0; i < legacy_fstab->num_entries; i++) {
+        legacy_fstab->recs[i].blk_device = strdup(fstab[i].blk_device.c_str());
+        legacy_fstab->recs[i].logical_partition_name =
+                strdup(fstab[i].logical_partition_name.c_str());
+        legacy_fstab->recs[i].mount_point = strdup(fstab[i].mount_point.c_str());
+        legacy_fstab->recs[i].fs_type = strdup(fstab[i].fs_type.c_str());
+        legacy_fstab->recs[i].flags = fstab[i].flags;
+        legacy_fstab->recs[i].fs_options = strdup(fstab[i].fs_options.c_str());
+        legacy_fstab->recs[i].fs_mgr_flags = fstab[i].fs_mgr_flags.val;
+        legacy_fstab->recs[i].key_loc = strdup(fstab[i].key_loc.c_str());
+        legacy_fstab->recs[i].key_dir = strdup(fstab[i].key_dir.c_str());
+        legacy_fstab->recs[i].verity_loc = strdup(fstab[i].verity_loc.c_str());
+        legacy_fstab->recs[i].length = fstab[i].length;
+        legacy_fstab->recs[i].label = strdup(fstab[i].label.c_str());
+        legacy_fstab->recs[i].partnum = fstab[i].partnum;
+        legacy_fstab->recs[i].swap_prio = fstab[i].swap_prio;
+        legacy_fstab->recs[i].max_comp_streams = fstab[i].max_comp_streams;
+        legacy_fstab->recs[i].zram_size = fstab[i].zram_size;
+        legacy_fstab->recs[i].reserved_size = fstab[i].reserved_size;
+        legacy_fstab->recs[i].file_contents_mode = fstab[i].file_contents_mode;
+        legacy_fstab->recs[i].file_names_mode = fstab[i].file_names_mode;
+        legacy_fstab->recs[i].erase_blk_size = fstab[i].erase_blk_size;
+        legacy_fstab->recs[i].logical_blk_size = fstab[i].logical_blk_size;
+        legacy_fstab->recs[i].sysfs_path = strdup(fstab[i].sysfs_path.c_str());
+    }
+    return legacy_fstab;
 }
 
 int fs_mgr_is_voldmanaged(const struct fstab_rec *fstab)
@@ -991,6 +999,10 @@
     return fstab->fs_mgr_flags & MF_NOFAIL;
 }
 
+int fs_mgr_is_first_stage_mount(const struct fstab_rec* fstab) {
+    return fstab->fs_mgr_flags & MF_FIRST_STAGE_MOUNT;
+}
+
 int fs_mgr_is_latemount(const struct fstab_rec* fstab) {
     return fstab->fs_mgr_flags & MF_LATEMOUNT;
 }
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index a1de005..d2d8dc1 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -74,7 +74,7 @@
     return false;
 }
 
-bool fs_mgr_overlayfs_mount_all(const std::vector<const fstab_rec*>&) {
+bool fs_mgr_overlayfs_mount_all(const std::vector<fstab_rec*>&) {
     return false;
 }
 
@@ -82,7 +82,7 @@
     return {};
 }
 
-std::vector<std::string> fs_mgr_overlayfs_required_devices(const std::vector<const fstab_rec*>&) {
+std::vector<std::string> fs_mgr_overlayfs_required_devices(const std::vector<fstab_rec*>&) {
     return {};
 }
 
@@ -96,6 +96,10 @@
     return false;
 }
 
+bool fs_mgr_overlayfs_is_setup() {
+    return false;
+}
+
 #else  // ALLOW_ADBD_DISABLE_VERITY == 0
 
 namespace {
@@ -273,9 +277,8 @@
 
 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);
-    });
+    fs_mgr_update_verity_state(
+            [&ret](const std::string& mount_point, int) { ret.emplace_back(mount_point); });
     return ret;
 }
 
@@ -382,8 +385,10 @@
     return SlotNumberForSlotSuffix(fs_mgr_get_slot_suffix());
 }
 
+const auto kPhysicalDevice = "/dev/block/by-name/"s;
+
 std::string fs_mgr_overlayfs_super_device(uint32_t slot_number) {
-    return "/dev/block/by-name/" + fs_mgr_get_super_partition_name(slot_number);
+    return kPhysicalDevice + fs_mgr_get_super_partition_name(slot_number);
 }
 
 bool fs_mgr_overlayfs_has_logical(const fstab* fstab) {
@@ -395,6 +400,18 @@
     return false;
 }
 
+void fs_mgr_overlayfs_umount_scratch() {
+    // Lazy umount will allow us to move on and possibly later
+    // establish a new fresh mount without requiring a reboot should
+    // the developer wish to restart.  Old references should melt
+    // away or have no data.  Main goal is to shut the door on the
+    // current overrides with an expectation of a subsequent reboot,
+    // thus any errors here are ignored.
+    umount2(kScratchMountPoint.c_str(), MNT_DETACH);
+    LINFO << "umount(" << kScratchMountPoint << ")";
+    rmdir(kScratchMountPoint.c_str());
+}
+
 // reduce 'DM_DEV_STATUS failed for scratch: No such device or address' noise
 std::string scratch_device_cache;
 
@@ -408,13 +425,7 @@
 
     auto save_errno = errno;
     if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {
-        // Lazy umount will allow us to move on and possibly later
-        // establish a new fresh mount without requiring a reboot should
-        // the developer wish to restart.  Old references should melt
-        // away or have no data.  Main goal is to shut the door on the
-        // current overrides with an expectation of a subsequent reboot,
-        // thus any errors here are ignored.
-        umount2(kScratchMountPoint.c_str(), MNT_DETACH);
+        fs_mgr_overlayfs_umount_scratch();
     }
     auto builder = MetadataBuilder::New(super_device, slot_number);
     if (!builder) {
@@ -432,7 +443,7 @@
         if (change) *change = true;
         if (!DestroyLogicalPartition(partition_name, 0s)) return false;
     } else {
-        PERROR << "delete partition " << overlay;
+        LERROR << "delete partition " << overlay;
         return false;
     }
     errno = save_errno;
@@ -635,72 +646,20 @@
 std::string fs_mgr_overlayfs_scratch_device() {
     if (!scratch_device_cache.empty()) return scratch_device_cache;
 
-    auto& dm = DeviceMapper::Instance();
-    const auto partition_name = android::base::Basename(kScratchMountPoint);
-    std::string path;
-    if (!dm.GetDmDevicePathByName(partition_name, &path)) return "";
+    // Is this a multiple super device (retrofit)?
+    auto slot_number = fs_mgr_overlayfs_slot_number();
+    auto super_device = fs_mgr_overlayfs_super_device(slot_number);
+    auto path = fs_mgr_overlayfs_super_device(slot_number == 0);
+    if (super_device == path) {
+        // Create from within single super device;
+        auto& dm = DeviceMapper::Instance();
+        const auto partition_name = android::base::Basename(kScratchMountPoint);
+        if (!dm.GetDmDevicePathByName(partition_name, &path)) return "";
+    }
     return scratch_device_cache = path;
 }
 
-// Create and mount kScratchMountPoint storage if we have logical partitions
-bool fs_mgr_overlayfs_setup_scratch(const fstab* fstab, bool* change) {
-    if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) return true;
-    auto mnt_type = fs_mgr_overlayfs_scratch_mount_type();
-    auto scratch_device = fs_mgr_overlayfs_scratch_device();
-    auto partition_exists = fs_mgr_rw_access(scratch_device);
-    if (!partition_exists) {
-        auto slot_number = fs_mgr_overlayfs_slot_number();
-        auto super_device = fs_mgr_overlayfs_super_device(slot_number);
-        if (!fs_mgr_rw_access(super_device)) return false;
-        if (!fs_mgr_overlayfs_has_logical(fstab)) return false;
-        auto builder = MetadataBuilder::New(super_device, slot_number);
-        if (!builder) {
-            PERROR << "open " << super_device << " metadata";
-            return false;
-        }
-        const auto partition_name = android::base::Basename(kScratchMountPoint);
-        partition_exists = builder->FindPartition(partition_name) != nullptr;
-        if (!partition_exists) {
-            auto partition = builder->AddPartition(partition_name, LP_PARTITION_ATTR_NONE);
-            if (!partition) {
-                PERROR << "create " << partition_name;
-                return false;
-            }
-            auto partition_size = builder->AllocatableSpace() - builder->UsedSpace();
-            // 512MB or half the remaining available space, whichever is greater.
-            partition_size = std::max(uint64_t(512 * 1024 * 1024), partition_size / 2);
-            if (!builder->ResizePartition(partition, partition_size)) {
-                PERROR << "resize " << partition_name;
-                return false;
-            }
-
-            auto metadata = builder->Export();
-            if (!metadata) {
-                LERROR << "generate new metadata " << partition_name;
-                return false;
-            }
-            if (!UpdatePartitionTable(super_device, *metadata.get(), slot_number)) {
-                LERROR << "update " << partition_name;
-                return false;
-            }
-
-            if (change) *change = true;
-        }
-
-        if (!CreateLogicalPartition(super_device, slot_number, partition_name, true, 0s,
-                                    &scratch_device))
-            return false;
-    }
-
-    if (partition_exists) {
-        if (fs_mgr_overlayfs_mount_scratch(scratch_device, mnt_type)) {
-            if (change) *change = true;
-            return true;
-        }
-        // partition existed, but was not initialized;
-        errno = 0;
-    }
-
+bool fs_mgr_overlayfs_make_scratch(const std::string& scratch_device, const std::string& mnt_type) {
     // Force mkfs by design for overlay support of adb remount, simplify and
     // thus do not rely on fsck to correct problems that could creep in.
     auto command = ""s;
@@ -709,6 +668,7 @@
     } else if (mnt_type == "ext4") {
         command = kMkExt4 + " -b 4096 -t ext4 -m 0 -O has_journal -M " + kScratchMountPoint;
     } else {
+        errno = ESRCH;
         LERROR << mnt_type << " has no mkfs cookbook";
         return false;
     }
@@ -718,6 +678,114 @@
         LERROR << "make " << mnt_type << " filesystem on " << scratch_device << " return=" << ret;
         return false;
     }
+    return true;
+}
+
+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);
+    auto partition_create = !*partition_exists;
+    // Do we need to create a logical "scratch" partition?
+    if (!partition_create && android::base::StartsWith(*scratch_device, kPhysicalDevice)) {
+        return true;
+    }
+    auto slot_number = fs_mgr_overlayfs_slot_number();
+    auto super_device = fs_mgr_overlayfs_super_device(slot_number);
+    if (!fs_mgr_rw_access(super_device)) return false;
+    if (!fs_mgr_overlayfs_has_logical(fstab)) return false;
+    auto builder = MetadataBuilder::New(super_device, slot_number);
+    if (!builder) {
+        LERROR << "open " << super_device << " metadata";
+        return false;
+    }
+    const auto partition_name = android::base::Basename(kScratchMountPoint);
+    auto partition = builder->FindPartition(partition_name);
+    *partition_exists = partition != nullptr;
+    auto changed = false;
+    if (!*partition_exists) {
+        partition = builder->AddPartition(partition_name, LP_PARTITION_ATTR_NONE);
+        if (!partition) {
+            LERROR << "create " << partition_name;
+            return false;
+        }
+        changed = true;
+    }
+    // Take half of free space, minimum 512MB or maximum free - margin.
+    static constexpr auto kMinimumSize = uint64_t(512 * 1024 * 1024);
+    if (partition->size() < kMinimumSize) {
+        auto partition_size =
+                builder->AllocatableSpace() - builder->UsedSpace() + partition->size();
+        if ((partition_size > kMinimumSize) || !partition->size()) {
+            // Leave some space for free space jitter of a few erase
+            // blocks, in case they are needed for any individual updates
+            // to any other partition that needs to be flashed while
+            // overlayfs is in force.  Of course if margin_size is not
+            // enough could normally get a flash failure, so
+            // ResizePartition() will delete the scratch partition in
+            // order to fulfill.  Deleting scratch will destroy all of
+            // the adb remount overrides :-( .
+            auto margin_size = uint64_t(3 * 256 * 1024);
+            BlockDeviceInfo info;
+            if (builder->GetBlockDeviceInfo(partition_name, &info)) {
+                margin_size = 3 * info.logical_block_size;
+            }
+            partition_size = std::max(std::min(kMinimumSize, partition_size - margin_size),
+                                      partition_size / 2);
+            if (partition_size > partition->size()) {
+                if (!builder->ResizePartition(partition, partition_size)) {
+                    LERROR << "resize " << partition_name;
+                    return false;
+                }
+                if (!partition_create) DestroyLogicalPartition(partition_name, 10s);
+                changed = true;
+                *partition_exists = false;
+            }
+        }
+    }
+    // land the update back on to the partition
+    if (changed) {
+        auto metadata = builder->Export();
+        if (!metadata || !UpdatePartitionTable(super_device, *metadata.get(), slot_number)) {
+            LERROR << "add partition " << partition_name;
+            return false;
+        }
+
+        if (change) *change = true;
+    }
+
+    if (changed || partition_create) {
+        if (!CreateLogicalPartition(super_device, slot_number, partition_name, true, 0s,
+                                    scratch_device))
+            return false;
+
+        if (change) *change = true;
+    }
+    return true;
+}
+
+// Create and mount kScratchMountPoint storage if we have logical partitions
+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;
+    bool partition_exists;
+    if (!fs_mgr_overlayfs_create_scratch(fstab, &scratch_device, &partition_exists, change)) {
+        return false;
+    }
+
+    // If the partition exists, assume first that it can be mounted.
+    auto mnt_type = fs_mgr_overlayfs_scratch_mount_type();
+    if (partition_exists) {
+        if (fs_mgr_overlayfs_mount_scratch(scratch_device, mnt_type)) {
+            if (change) *change = true;
+            return true;
+        }
+        // partition existed, but was not initialized; fall through to make it.
+        errno = 0;
+    }
+
+    if (!fs_mgr_overlayfs_make_scratch(scratch_device, mnt_type)) return false;
 
     if (change) *change = true;
 
@@ -727,6 +795,7 @@
 bool fs_mgr_overlayfs_scratch_can_be_mounted(const std::string& scratch_device) {
     if (scratch_device.empty()) return false;
     if (fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) return false;
+    if (android::base::StartsWith(scratch_device, kPhysicalDevice)) return true;
     if (fs_mgr_rw_access(scratch_device)) return true;
     auto slot_number = fs_mgr_overlayfs_slot_number();
     auto super_device = fs_mgr_overlayfs_super_device(slot_number);
@@ -736,14 +805,20 @@
     return builder->FindPartition(android::base::Basename(kScratchMountPoint)) != nullptr;
 }
 
+bool fs_mgr_overlayfs_invalid(const fstab* fstab) {
+    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;
+}
+
 }  // namespace
 
 bool fs_mgr_overlayfs_mount_all(fstab* fstab) {
     auto ret = false;
-
-    if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) return ret;
-
-    if (!fstab) return ret;
+    if (fs_mgr_overlayfs_invalid(fstab)) return ret;
 
     auto scratch_can_be_mounted = true;
     for (const auto& mount_point : fs_mgr_candidate_list(fstab)) {
@@ -756,8 +831,7 @@
                 fs_mgr_overlayfs_mount_scratch(scratch_device,
                                                fs_mgr_overlayfs_scratch_mount_type()) &&
                 !fs_mgr_access(kScratchMountPoint + kOverlayTopDir)) {
-                umount2(kScratchMountPoint.c_str(), MNT_DETACH);
-                rmdir(kScratchMountPoint.c_str());
+                fs_mgr_overlayfs_umount_scratch();
             }
         }
         if (fs_mgr_overlayfs_mount(mount_point)) ret = true;
@@ -765,7 +839,7 @@
     return ret;
 }
 
-bool fs_mgr_overlayfs_mount_all(const std::vector<const fstab_rec*>& fsrecs) {
+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]};
@@ -773,7 +847,9 @@
 }
 
 std::vector<std::string> fs_mgr_overlayfs_required_devices(fstab* fstab) {
-    if (fs_mgr_get_entry_for_mount_point(const_cast<struct fstab*>(fstab), kScratchMountPoint)) {
+    if (fs_mgr_overlayfs_invalid(fstab)) return {};
+
+    if (fs_mgr_get_entry_for_mount_point(fstab, kScratchMountPoint)) {
         return {};
     }
 
@@ -786,8 +862,7 @@
     return {};
 }
 
-std::vector<std::string> fs_mgr_overlayfs_required_devices(
-        const std::vector<const fstab_rec*>& fsrecs) {
+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]};
@@ -848,6 +923,7 @@
     auto ret = true;
     // If scratch exists, but is not mounted, lets gain access to clean
     // specific override entries.
+    auto mount_scratch = false;
     if ((mount_point != nullptr) && !fs_mgr_overlayfs_already_mounted(kScratchMountPoint, false)) {
         auto scratch_device = fs_mgr_overlayfs_scratch_device();
         if (scratch_device.empty()) {
@@ -857,7 +933,8 @@
             CreateLogicalPartition(super_device, slot_number, partition_name, true, 0s,
                                    &scratch_device);
         }
-        fs_mgr_overlayfs_mount_scratch(scratch_device, fs_mgr_overlayfs_scratch_mount_type());
+        mount_scratch = fs_mgr_overlayfs_mount_scratch(scratch_device,
+                                                       fs_mgr_overlayfs_scratch_mount_type());
     }
     for (const auto& overlay_mount_point : kOverlayMountPoints) {
         ret &= fs_mgr_overlayfs_teardown_one(overlay_mount_point, mount_point ?: "", change);
@@ -875,9 +952,22 @@
         PERROR << "teardown";
         ret = false;
     }
+    if (mount_scratch) fs_mgr_overlayfs_umount_scratch();
+
     return ret;
 }
 
+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())) {
+        if (fs_mgr_overlayfs_already_mounted(mount_point)) return true;
+    }
+    return false;
+}
+
 #endif  // ALLOW_ADBD_DISABLE_VERITY != 0
 
 bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string& dev) {
diff --git a/fs_mgr/fs_mgr_priv.h b/fs_mgr/fs_mgr_priv.h
index 23a92d3..faef34b 100644
--- a/fs_mgr/fs_mgr_priv.h
+++ b/fs_mgr/fs_mgr_priv.h
@@ -21,8 +21,9 @@
 #include <string>
 
 #include <android-base/logging.h>
+#include <fs_mgr.h>
+#include <fstab/fstab.h>
 
-#include "fs_mgr.h"
 #include "fs_mgr_priv_boot_config.h"
 
 /* The CHECK() in logging.h will use program invocation name as the tag.
@@ -117,6 +118,8 @@
 #define MF_LOGICAL        0x10000000
 #define MF_CHECKPOINT_BLK 0x20000000
 #define MF_CHECKPOINT_FS  0x40000000
+#define MF_FIRST_STAGE_MOUNT \
+                          0x80000000
 // clang-format on
 
 #define DM_BUF_SIZE 4096
@@ -129,8 +132,8 @@
                           const std::chrono::milliseconds relative_timeout,
                           FileWaitMode wait_mode = FileWaitMode::Exists);
 
-int fs_mgr_set_blk_ro(const char* blockdev);
-bool fs_mgr_update_for_slotselect(fstab* fstab);
+bool fs_mgr_set_blk_ro(const std::string& blockdev);
+bool fs_mgr_update_for_slotselect(Fstab* fstab);
 bool fs_mgr_is_device_unlocked();
 const std::string& get_android_dt_dir();
 bool is_dt_compatible();
diff --git a/fs_mgr/fs_mgr_slotselect.cpp b/fs_mgr/fs_mgr_slotselect.cpp
index 3b01d0e..20d60ae 100644
--- a/fs_mgr/fs_mgr_slotselect.cpp
+++ b/fs_mgr/fs_mgr_slotselect.cpp
@@ -31,36 +31,23 @@
 }
 
 // Updates |fstab| for slot_suffix. Returns true on success, false on error.
-bool fs_mgr_update_for_slotselect(struct fstab *fstab) {
+bool fs_mgr_update_for_slotselect(Fstab* fstab) {
     int n;
     std::string ab_suffix;
 
-    for (n = 0; n < fstab->num_entries; n++) {
-        fstab_rec& record = fstab->recs[n];
-        if (record.fs_mgr_flags & MF_SLOTSELECT) {
-            if (ab_suffix.empty()) {
-                ab_suffix = fs_mgr_get_slot_suffix();
-                // Return false if failed to get ab_suffix when MF_SLOTSELECT is specified.
-                if (ab_suffix.empty()) return false;
-            }
-
-            char* new_blk_device;
-            if (asprintf(&new_blk_device, "%s%s", record.blk_device, ab_suffix.c_str()) <= 0) {
-                return false;
-            }
-            free(record.blk_device);
-            record.blk_device = new_blk_device;
-
-            char* new_partition_name;
-            if (record.logical_partition_name) {
-                if (asprintf(&new_partition_name, "%s%s", record.logical_partition_name,
-                             ab_suffix.c_str()) <= 0) {
-                    return false;
-                }
-                free(record.logical_partition_name);
-                record.logical_partition_name = new_partition_name;
-            }
+    for (auto& entry : *fstab) {
+        if (!entry.fs_mgr_flags.slot_select) {
+            continue;
         }
+
+        if (ab_suffix.empty()) {
+            ab_suffix = fs_mgr_get_slot_suffix();
+            // Return false if failed to get ab_suffix when MF_SLOTSELECT is specified.
+            if (ab_suffix.empty()) return false;
+        }
+
+        entry.blk_device = entry.blk_device + ab_suffix;
+        entry.logical_partition_name = entry.logical_partition_name + ab_suffix;
     }
     return true;
 }
diff --git a/fs_mgr/fs_mgr_vendor_overlay.cpp b/fs_mgr/fs_mgr_vendor_overlay.cpp
index e1815ff..830f0dd 100644
--- a/fs_mgr/fs_mgr_vendor_overlay.cpp
+++ b/fs_mgr/fs_mgr_vendor_overlay.cpp
@@ -35,43 +35,42 @@
 
 namespace {
 
-const auto kVendorOverlaySourceDir = "/system/vendor_overlay/"s;
+// The order of the list means the priority to show the files in the directory.
+// The last one has the highest priority.
+const std::vector<const std::string> kVendorOverlaySourceDirs = {
+        "/system/vendor_overlay/",
+        "/product/vendor_overlay/",
+};
 const auto kVndkVersionPropertyName = "ro.vndk.version"s;
 const auto kVendorTopDir = "/vendor/"s;
 const auto kLowerdirOption = "lowerdir="s;
 
-std::string fs_mgr_get_vendor_overlay_top_dir() {
-    // VNDK version is provided by the /vendor/default.prop
-    // To read the property, it must be called at the second init stage after the default
-    // properties are loaded.
-    std::string vndk_version = android::base::GetProperty(kVndkVersionPropertyName, "");
-    if (vndk_version.empty()) {
-        return "";
-    }
-    return kVendorOverlaySourceDir + vndk_version;
-}
+std::vector<std::pair<std::string, std::string>> fs_mgr_get_vendor_overlay_dirs(
+        const std::string& vndk_version) {
+    std::vector<std::pair<std::string, std::string>> vendor_overlay_dirs;
+    for (const auto& vendor_overlay_source : kVendorOverlaySourceDirs) {
+        const auto overlay_top = vendor_overlay_source + vndk_version;
+        std::unique_ptr<DIR, decltype(&closedir)> vendor_overlay_top(opendir(overlay_top.c_str()),
+                                                                     closedir);
+        if (!vendor_overlay_top) continue;
 
-std::vector<std::string> fs_mgr_get_vendor_overlay_dirs(const std::string& overlay_top) {
-    std::vector<std::string> vendor_overlay_dirs;
-    std::unique_ptr<DIR, decltype(&closedir)> vendor_overlay_top(opendir(overlay_top.c_str()),
-                                                                 closedir);
-    if (!vendor_overlay_top) return vendor_overlay_dirs;
+        // Vendor overlay root for current vendor version found!
+        LINFO << "vendor overlay root: " << overlay_top;
 
-    // Vendor overlay root for current vendor version found!
-    LINFO << "vendor overlay root: " << overlay_top;
-    struct dirent* dp;
-    while ((dp = readdir(vendor_overlay_top.get())) != nullptr) {
-        if (dp->d_type != DT_DIR || dp->d_name[0] == '.') {
-            continue;
+        struct dirent* dp;
+        while ((dp = readdir(vendor_overlay_top.get())) != nullptr) {
+            if (dp->d_type != DT_DIR || dp->d_name[0] == '.') {
+                continue;
+            }
+            vendor_overlay_dirs.emplace_back(overlay_top, dp->d_name);
         }
-        vendor_overlay_dirs.push_back(dp->d_name);
     }
-
     return vendor_overlay_dirs;
 }
 
-bool fs_mgr_vendor_overlay_mount(const std::string& overlay_top, const std::string& mount_point) {
-    const auto vendor_mount_point = kVendorTopDir + mount_point;
+bool fs_mgr_vendor_overlay_mount(const std::pair<std::string, std::string>& mount_point) {
+    const auto [overlay_top, mount_dir] = mount_point;
+    const auto vendor_mount_point = kVendorTopDir + mount_dir;
     LINFO << "vendor overlay mount on " << vendor_mount_point;
 
     const auto target_context = fs_mgr_get_context(vendor_mount_point);
@@ -79,7 +78,7 @@
         PERROR << " failed: cannot find the target vendor mount point";
         return false;
     }
-    const auto source_directory = overlay_top + "/" + mount_point;
+    const auto source_directory = overlay_top + "/" + mount_dir;
     const auto source_context = fs_mgr_get_context(source_directory);
     if (target_context != source_context) {
         LERROR << " failed: source and target contexts do not match (source:" << source_context
@@ -112,22 +111,25 @@
 // To read the properties, vendor overlay must be mounted at the second stage, right
 // after "property_load_boot_defaults()" is called.
 bool fs_mgr_vendor_overlay_mount_all() {
-    const auto overlay_top = fs_mgr_get_vendor_overlay_top_dir();
-    if (overlay_top.empty()) {
+    // To read the property, it must be called at the second init stage after the default
+    // properties are loaded.
+    static const auto vndk_version = android::base::GetProperty(kVndkVersionPropertyName, "");
+    if (vndk_version.empty()) {
         LINFO << "vendor overlay: vndk version not defined";
         return false;
     }
-    const auto vendor_overlay_dirs = fs_mgr_get_vendor_overlay_dirs(overlay_top);
+
+    const auto vendor_overlay_dirs = fs_mgr_get_vendor_overlay_dirs(vndk_version);
     if (vendor_overlay_dirs.empty()) return true;
     if (fs_mgr_overlayfs_valid() == OverlayfsValidResult::kNotSupported) {
         LINFO << "vendor overlay: kernel does not support overlayfs";
         return false;
     }
 
-    // Mount each directory in /system/vendor_overlay/<ver> on /vendor
+    // Mount each directory in /(system|product)/vendor_overlay/<ver> on /vendor
     auto ret = true;
     for (const auto& vendor_overlay_dir : vendor_overlay_dirs) {
-        if (!fs_mgr_vendor_overlay_mount(overlay_top, vendor_overlay_dir)) {
+        if (!fs_mgr_vendor_overlay_mount(vendor_overlay_dir)) {
             ret = false;
         }
     }
diff --git a/fs_mgr/include/fs_mgr.h b/fs_mgr/include/fs_mgr.h
index 5dabe76..c1dc731 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
@@ -77,8 +73,9 @@
 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);
-int fs_mgr_swapon_all(struct fstab *fstab);
+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(struct fstab_rec* rec);
 
 int fs_mgr_do_format(fstab_rec* fstab, bool reserve_footer);
diff --git a/fs_mgr/include/fs_mgr_dm_linear.h b/fs_mgr/include/fs_mgr_dm_linear.h
index 66abfca..f065071 100644
--- a/fs_mgr/include/fs_mgr_dm_linear.h
+++ b/fs_mgr/include/fs_mgr_dm_linear.h
@@ -43,7 +43,7 @@
 
 // Create block devices for all logical partitions in the given metadata. The
 // metadata must have been read from the current slot.
-bool CreateLogicalPartitions(const LpMetadata& metadata);
+bool CreateLogicalPartitions(const LpMetadata& metadata, const std::string& block_device);
 
 // Create block devices for all logical partitions. This is a convenience
 // method for ReadMetadata and CreateLogicalPartitions.
diff --git a/fs_mgr/include/fs_mgr_overlayfs.h b/fs_mgr/include/fs_mgr_overlayfs.h
index deaf4cb..0dd9121 100644
--- a/fs_mgr/include/fs_mgr_overlayfs.h
+++ b/fs_mgr/include/fs_mgr_overlayfs.h
@@ -22,13 +22,13 @@
 #include <vector>
 
 bool fs_mgr_overlayfs_mount_all(fstab* fstab);
-bool fs_mgr_overlayfs_mount_all(const std::vector<const fstab_rec*>& 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<const fstab_rec*>& fstab);
+std::vector<std::string> fs_mgr_overlayfs_required_devices(const std::vector<fstab_rec*>& 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);
+bool fs_mgr_overlayfs_is_setup();
 bool fs_mgr_has_shared_blocks(const std::string& mount_point, const std::string& dev);
 std::string fs_mgr_get_context(const std::string& mount_point);
 
diff --git a/fs_mgr/include_fstab/fstab/fstab.h b/fs_mgr/include_fstab/fstab/fstab.h
index bb40511..4706028 100644
--- a/fs_mgr/include_fstab/fstab/fstab.h
+++ b/fs_mgr/include_fstab/fstab/fstab.h
@@ -14,16 +14,17 @@
  * limitations under the License.
  */
 
-#ifndef __CORE_FS_TAB_H
-#define __CORE_FS_TAB_H
+#pragma once
 
 #include <linux/dm-ioctl.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <sys/types.h>
 
 #include <set>
 #include <string>
+#include <vector>
 
 /*
  * The entries must be kept in the same order as they were seen in the fstab.
@@ -46,17 +47,17 @@
     char* key_loc;
     char* key_dir;
     char* verity_loc;
-    long long length;
+    off64_t length;
     char* label;
     int partnum;
     int swap_prio;
     int max_comp_streams;
-    unsigned int zram_size;
-    uint64_t reserved_size;
-    unsigned int file_contents_mode;
-    unsigned int file_names_mode;
-    unsigned int erase_blk_size;
-    unsigned int logical_blk_size;
+    off64_t zram_size;
+    off64_t reserved_size;
+    int file_contents_mode;
+    int file_names_mode;
+    off64_t erase_blk_size;
+    off64_t logical_blk_size;
     char* sysfs_path;
 };
 
@@ -83,6 +84,7 @@
 int fs_mgr_is_formattable(const struct fstab_rec* fstab);
 int fs_mgr_is_slotselect(const struct fstab_rec* fstab);
 int fs_mgr_is_nofail(const struct fstab_rec* fstab);
+int fs_mgr_is_first_stage_mount(const struct fstab_rec* fstab);
 int fs_mgr_is_latemount(const struct fstab_rec* fstab);
 int fs_mgr_is_quota(const struct fstab_rec* fstab);
 int fs_mgr_is_logical(const struct fstab_rec* fstab);
@@ -94,4 +96,82 @@
 std::string fs_mgr_get_slot_suffix();
 std::set<std::string> fs_mgr_get_boot_devices();
 
-#endif /* __CORE_FS_TAB_H */
+struct FstabEntry {
+    std::string blk_device;
+    std::string logical_partition_name;
+    std::string mount_point;
+    std::string fs_type;
+    unsigned long flags = 0;
+    std::string fs_options;
+    std::string key_loc;
+    std::string key_dir;
+    std::string verity_loc;
+    off64_t length = 0;
+    std::string label;
+    int partnum = -1;
+    int swap_prio = -1;
+    int max_comp_streams = 0;
+    off64_t zram_size = 0;
+    off64_t reserved_size = 0;
+    int file_contents_mode = 0;
+    int file_names_mode = 0;
+    off64_t erase_blk_size = 0;
+    off64_t logical_blk_size = 0;
+    std::string sysfs_path;
+
+    // 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;
+        struct {
+            bool wait : 1;
+            bool check : 1;
+            bool crypt : 1;
+            bool nonremovable : 1;
+            bool vold_managed : 1;
+            bool length : 1;
+            bool recovery_only : 1;
+            bool swap_prio : 1;
+            bool zram_size : 1;
+            bool verify : 1;
+            bool force_crypt : 1;
+            bool no_emulated_sd : 1;  // No emulated sdcard daemon; sd card is the only external
+                                      // storage.
+            bool no_trim : 1;
+            bool file_encryption : 1;
+            bool formattable : 1;
+            bool slot_select : 1;
+            bool force_fde_or_fbe : 1;
+            bool late_mount : 1;
+            bool no_fail : 1;
+            bool verify_at_boot : 1;
+            bool max_comp_streams : 1;
+            bool reserved_size : 1;
+            bool quota : 1;
+            bool erase_blk_size : 1;
+            bool logical_blk_size : 1;
+            bool avb : 1;
+            bool key_directory : 1;
+            bool sysfs : 1;
+            bool logical : 1;
+            bool checkpoint_blk : 1;
+            bool checkpoint_fs : 1;
+        };
+    } fs_mgr_flags;
+
+    bool is_encryptable() const {
+        return fs_mgr_flags.crypt || fs_mgr_flags.force_crypt || fs_mgr_flags.force_fde_or_fbe;
+    }
+};
+
+// An Fstab is a collection of FstabEntry structs.
+using Fstab = std::vector<FstabEntry>;
+
+bool ReadFstabFromFile(const std::string& path, Fstab* fstab);
+bool ReadFstabFromDt(Fstab* fstab);
+bool ReadDefaultFstab(Fstab* fstab);
+
+// Temporary conversion functions.
+FstabEntry FstabRecToFstabEntry(const fstab_rec* fstab_rec);
+Fstab LegacyFstabToFstab(const struct fstab* legacy_fstab);
+fstab* FstabToLegacyFstab(const Fstab& fstab);
diff --git a/fs_mgr/fs_mgr_avb_ops.cpp b/fs_mgr/libfs_avb/avb_ops.cpp
similarity index 93%
rename from fs_mgr/fs_mgr_avb_ops.cpp
rename to fs_mgr/libfs_avb/avb_ops.cpp
index 18efa22..f56a517 100644
--- a/fs_mgr/fs_mgr_avb_ops.cpp
+++ b/fs_mgr/libfs_avb/avb_ops.cpp
@@ -22,7 +22,7 @@
  * SOFTWARE.
  */
 
-#include "fs_mgr_priv_avb_ops.h"
+#include "avb_ops.h"
 
 #include <errno.h>
 #include <fcntl.h>
@@ -37,15 +37,17 @@
 #include <libavb/libavb.h>
 #include <utils/Compat.h>
 
-#include "fs_mgr.h"
 #include "fs_mgr_priv.h"
 
 using namespace std::literals;
 
+namespace android {
+namespace fs_mgr {
+
 static AvbIOResult read_from_partition(AvbOps* ops, const char* partition, int64_t offset,
                                        size_t num_bytes, void* buffer, size_t* out_num_read) {
     return FsManagerAvbOps::GetInstanceFromAvbOps(ops)->ReadFromPartition(
-        partition, offset, num_bytes, buffer, out_num_read);
+            partition, offset, num_bytes, buffer, out_num_read);
 }
 
 static AvbIOResult dummy_read_rollback_index(AvbOps* ops ATTRIBUTE_UNUSED,
@@ -58,9 +60,10 @@
 }
 
 static AvbIOResult dummy_validate_vbmeta_public_key(
-    AvbOps* ops ATTRIBUTE_UNUSED, const uint8_t* public_key_data ATTRIBUTE_UNUSED,
-    size_t public_key_length ATTRIBUTE_UNUSED, const uint8_t* public_key_metadata ATTRIBUTE_UNUSED,
-    size_t public_key_metadata_length ATTRIBUTE_UNUSED, bool* out_is_trusted) {
+        AvbOps* ops ATTRIBUTE_UNUSED, const uint8_t* public_key_data ATTRIBUTE_UNUSED,
+        size_t public_key_length ATTRIBUTE_UNUSED,
+        const uint8_t* public_key_metadata ATTRIBUTE_UNUSED,
+        size_t public_key_metadata_length ATTRIBUTE_UNUSED, bool* out_is_trusted) {
     // vbmeta public key has been checked in bootloader phase.
     // In user-space, returns true to pass the check.
     //
@@ -178,3 +181,6 @@
     return avb_slot_verify(&avb_ops_, requested_partitions, ab_suffix.c_str(), flags,
                            AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE, out_data);
 }
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/fs_mgr_priv_avb_ops.h b/fs_mgr/libfs_avb/avb_ops.h
similarity index 89%
rename from fs_mgr/fs_mgr_priv_avb_ops.h
rename to fs_mgr/libfs_avb/avb_ops.h
index 44eb1da..e6b33c2 100644
--- a/fs_mgr/fs_mgr_priv_avb_ops.h
+++ b/fs_mgr/libfs_avb/avb_ops.h
@@ -22,15 +22,14 @@
  * SOFTWARE.
  */
 
-#ifndef __CORE_FS_MGR_PRIV_AVB_OPS_H
-#define __CORE_FS_MGR_PRIV_AVB_OPS_H
+#pragma once
 
-#include <map>
 #include <string>
 
 #include <libavb/libavb.h>
 
-#include "fs_mgr.h"
+namespace android {
+namespace fs_mgr {
 
 // This class provides C++ bindings to interact with libavb, a small
 // self-contained piece of code that's intended to be used in bootloaders.
@@ -42,7 +41,7 @@
 //     read and verify the metadata and store it into the out_data parameter.
 //     The caller MUST check the integrity of metadata against the
 //     androidboot.vbmeta.{hash_alg, size, digest} values from /proc/cmdline.
-//     e.g., see class FsManagerAvbVerifier for more details.
+//     e.g., see class AvbVerifier for more details.
 //
 class FsManagerAvbOps {
   public:
@@ -60,6 +59,7 @@
 
   private:
     AvbOps avb_ops_;
-    std::map<std::string, std::string> by_name_symlink_map_;
 };
-#endif /* __CORE_FS_MGR_PRIV_AVB_OPS_H */
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/fs_mgr_avb.cpp b/fs_mgr/libfs_avb/fs_avb.cpp
similarity index 86%
rename from fs_mgr/fs_mgr_avb.cpp
rename to fs_mgr/libfs_avb/fs_avb.cpp
index 6f94d45..c4accad 100644
--- a/fs_mgr/fs_mgr_avb.cpp
+++ b/fs_mgr/libfs_avb/fs_avb.cpp
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "fs_mgr_avb.h"
+#include "fs_avb/fs_avb.h"
 
 #include <fcntl.h>
 #include <libgen.h>
@@ -35,10 +35,12 @@
 #include <libavb/libavb.h>
 #include <libdm/dm.h>
 
-#include "fs_mgr.h"
+#include "avb_ops.h"
 #include "fs_mgr_priv.h"
-#include "fs_mgr_priv_avb_ops.h"
-#include "fs_mgr_priv_sha.h"
+#include "sha.h"
+
+namespace android {
+namespace fs_mgr {
 
 static inline bool nibble_value(const char& c, uint8_t* value) {
     FS_MGR_CHECK(value != nullptr);
@@ -117,14 +119,14 @@
 //   - androidboot.vbmeta.hash_alg
 //   - androidboot.vbmeta.size
 //   - androidboot.vbmeta.digest
-class FsManagerAvbVerifier {
+class AvbVerifier {
   public:
-    // The factory method to return a unique_ptr<FsManagerAvbVerifier>
-    static std::unique_ptr<FsManagerAvbVerifier> Create();
+    // The factory method to return a unique_ptr<AvbVerifier>
+    static std::unique_ptr<AvbVerifier> Create();
     bool VerifyVbmetaImages(const AvbSlotVerifyData& verify_data);
 
   protected:
-    FsManagerAvbVerifier() = default;
+    AvbVerifier() = default;
 
   private:
     enum HashAlgorithm {
@@ -138,10 +140,10 @@
     size_t vbmeta_size_;
 };
 
-std::unique_ptr<FsManagerAvbVerifier> FsManagerAvbVerifier::Create() {
-    std::unique_ptr<FsManagerAvbVerifier> avb_verifier(new FsManagerAvbVerifier());
+std::unique_ptr<AvbVerifier> AvbVerifier::Create() {
+    std::unique_ptr<AvbVerifier> avb_verifier(new AvbVerifier());
     if (!avb_verifier) {
-        LERROR << "Failed to create unique_ptr<FsManagerAvbVerifier>";
+        LERROR << "Failed to create unique_ptr<AvbVerifier>";
         return nullptr;
     }
 
@@ -184,7 +186,7 @@
     return avb_verifier;
 }
 
-bool FsManagerAvbVerifier::VerifyVbmetaImages(const AvbSlotVerifyData& verify_data) {
+bool AvbVerifier::VerifyVbmetaImages(const AvbSlotVerifyData& verify_data) {
     if (verify_data.num_vbmeta_images == 0) {
         LERROR << "No vbmeta images";
         return false;
@@ -195,10 +197,10 @@
 
     if (hash_alg_ == kSHA256) {
         std::tie(total_size, digest_matched) =
-            verify_vbmeta_digest<SHA256Hasher>(verify_data, digest_);
+                verify_vbmeta_digest<SHA256Hasher>(verify_data, digest_);
     } else if (hash_alg_ == kSHA512) {
         std::tie(total_size, digest_matched) =
-            verify_vbmeta_digest<SHA512Hasher>(verify_data, digest_);
+                verify_vbmeta_digest<SHA512Hasher>(verify_data, digest_);
     }
 
     if (total_size != vbmeta_size_) {
@@ -268,7 +270,8 @@
                                      const std::string& salt, const std::string& root_digest,
                                      bool wait_for_verity_dev) {
     android::dm::DmTable table;
-    if (!construct_verity_table(hashtree_desc, salt, root_digest, fstab_entry->blk_device, &table) ||
+    if (!construct_verity_table(hashtree_desc, salt, root_digest, fstab_entry->blk_device,
+                                &table) ||
         !table.valid()) {
         LERROR << "Failed to construct verity table.";
         return false;
@@ -314,9 +317,9 @@
         // Get descriptors from vbmeta_images[i].
         size_t num_descriptors;
         std::unique_ptr<const AvbDescriptor* [], decltype(&avb_free)> descriptors(
-            avb_descriptor_get_all(verify_data.vbmeta_images[i].vbmeta_data,
-                                   verify_data.vbmeta_images[i].vbmeta_size, &num_descriptors),
-            avb_free);
+                avb_descriptor_get_all(verify_data.vbmeta_images[i].vbmeta_data,
+                                       verify_data.vbmeta_images[i].vbmeta_size, &num_descriptors),
+                avb_free);
 
         if (!descriptors || num_descriptors < 1) {
             continue;
@@ -329,9 +332,10 @@
                 continue;
             }
             if (desc.tag == AVB_DESCRIPTOR_TAG_HASHTREE) {
-                desc_partition_name = (const uint8_t*)descriptors[j] + sizeof(AvbHashtreeDescriptor);
+                desc_partition_name =
+                        (const uint8_t*)descriptors[j] + sizeof(AvbHashtreeDescriptor);
                 if (!avb_hashtree_descriptor_validate_and_byteswap(
-                        (AvbHashtreeDescriptor*)descriptors[j], out_hashtree_desc)) {
+                            (AvbHashtreeDescriptor*)descriptors[j], out_hashtree_desc)) {
                     continue;
                 }
                 if (out_hashtree_desc->partition_name_len != partition_name.length()) {
@@ -361,12 +365,12 @@
     return true;
 }
 
-FsManagerAvbUniquePtr FsManagerAvbHandle::Open() {
+AvbUniquePtr AvbHandle::Open() {
     bool is_device_unlocked = fs_mgr_is_device_unlocked();
 
-    FsManagerAvbUniquePtr avb_handle(new FsManagerAvbHandle());
+    AvbUniquePtr avb_handle(new AvbHandle());
     if (!avb_handle) {
-        LERROR << "Failed to allocate FsManagerAvbHandle";
+        LERROR << "Failed to allocate AvbHandle";
         return nullptr;
     }
 
@@ -406,7 +410,7 @@
 
     // Sets the MAJOR.MINOR for init to set it into "ro.boot.avb_version".
     avb_handle->avb_version_ =
-        android::base::StringPrintf("%d.%d", AVB_VERSION_MAJOR, AVB_VERSION_MINOR);
+            android::base::StringPrintf("%d.%d", AVB_VERSION_MAJOR, AVB_VERSION_MINOR);
 
     // Checks whether FLAGS_VERIFICATION_DISABLED is set:
     //   - Only the top-level vbmeta struct is read.
@@ -414,18 +418,18 @@
     //     and AVB HASHTREE descriptor(s).
     AvbVBMetaImageHeader vbmeta_header;
     avb_vbmeta_image_header_to_host_byte_order(
-        (AvbVBMetaImageHeader*)avb_handle->avb_slot_data_->vbmeta_images[0].vbmeta_data,
-        &vbmeta_header);
-    bool verification_disabled =
-        ((AvbVBMetaImageFlags)vbmeta_header.flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED);
+            (AvbVBMetaImageHeader*)avb_handle->avb_slot_data_->vbmeta_images[0].vbmeta_data,
+            &vbmeta_header);
+    bool verification_disabled = ((AvbVBMetaImageFlags)vbmeta_header.flags &
+                                  AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED);
 
     if (verification_disabled) {
         avb_handle->status_ = kAvbHandleVerificationDisabled;
     } else {
         // Verifies vbmeta structs against the digest passed from bootloader in kernel cmdline.
-        std::unique_ptr<FsManagerAvbVerifier> avb_verifier = FsManagerAvbVerifier::Create();
+        std::unique_ptr<AvbVerifier> avb_verifier = AvbVerifier::Create();
         if (!avb_verifier) {
-            LERROR << "Failed to create FsManagerAvbVerifier";
+            LERROR << "Failed to create AvbVerifier";
             return nullptr;
         }
         if (!avb_verifier->VerifyVbmetaImages(*avb_handle->avb_slot_data_)) {
@@ -434,8 +438,8 @@
         }
 
         // Checks whether FLAGS_HASHTREE_DISABLED is set.
-        bool hashtree_disabled =
-            ((AvbVBMetaImageFlags)vbmeta_header.flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED);
+        bool hashtree_disabled = ((AvbVBMetaImageFlags)vbmeta_header.flags &
+                                  AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED);
         if (hashtree_disabled) {
             avb_handle->status_ = kAvbHandleHashtreeDisabled;
         }
@@ -445,16 +449,16 @@
     return avb_handle;
 }
 
-SetUpAvbHashtreeResult FsManagerAvbHandle::SetUpAvbHashtree(struct fstab_rec* fstab_entry,
-                                                            bool wait_for_verity_dev) {
+AvbHashtreeResult AvbHandle::SetUpAvbHashtree(struct fstab_rec* fstab_entry,
+                                              bool wait_for_verity_dev) {
     if (!fstab_entry || status_ == kAvbHandleUninitialized || !avb_slot_data_ ||
         avb_slot_data_->num_vbmeta_images < 1) {
-        return SetUpAvbHashtreeResult::kFail;
+        return AvbHashtreeResult::kFail;
     }
 
     if (status_ == kAvbHandleHashtreeDisabled || status_ == kAvbHandleVerificationDisabled) {
         LINFO << "AVB HASHTREE disabled on: " << fstab_entry->mount_point;
-        return SetUpAvbHashtreeResult::kDisabled;
+        return AvbHashtreeResult::kDisabled;
     }
 
     // Derives partition_name from blk_device to query the corresponding AVB HASHTREE descriptor
@@ -478,14 +482,17 @@
     std::string root_digest;
     if (!get_hashtree_descriptor(partition_name, *avb_slot_data_, &hashtree_descriptor, &salt,
                                  &root_digest)) {
-        return SetUpAvbHashtreeResult::kFail;
+        return AvbHashtreeResult::kFail;
     }
 
     // Converts HASHTREE descriptor to verity_table_params.
     if (!hashtree_dm_verity_setup(fstab_entry, hashtree_descriptor, salt, root_digest,
                                   wait_for_verity_dev)) {
-        return SetUpAvbHashtreeResult::kFail;
+        return AvbHashtreeResult::kFail;
     }
 
-    return SetUpAvbHashtreeResult::kSuccess;
+    return AvbHashtreeResult::kSuccess;
 }
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/include/fs_mgr_avb.h b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
similarity index 75%
rename from fs_mgr/include/fs_mgr_avb.h
rename to fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
index bb55a14..9adab3d 100644
--- a/fs_mgr/include/fs_mgr_avb.h
+++ b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
@@ -14,18 +14,18 @@
  * limitations under the License.
  */
 
-#ifndef __CORE_FS_MGR_AVB_H
-#define __CORE_FS_MGR_AVB_H
+#pragma once
 
-#include <map>
 #include <memory>
 #include <string>
 
+#include <fstab/fstab.h>
 #include <libavb/libavb.h>
 
-#include "fs_mgr.h"
+namespace android {
+namespace fs_mgr {
 
-enum class SetUpAvbHashtreeResult {
+enum class AvbHashtreeResult {
     kSuccess = 0,
     kFail,
     kDisabled,
@@ -33,17 +33,15 @@
 
 class FsManagerAvbOps;
 
-class FsManagerAvbHandle;
-using FsManagerAvbUniquePtr = std::unique_ptr<FsManagerAvbHandle>;
-
-using ByNameSymlinkMap = std::map<std::string, std::string>;
+class AvbHandle;
+using AvbUniquePtr = std::unique_ptr<AvbHandle>;
 
 // Provides a factory method to return a unique_ptr pointing to itself and the
 // SetUpAvbHashtree() function to extract dm-verity parameters from AVB HASHTREE
 // descriptors to load verity table into kernel through ioctl.
-class FsManagerAvbHandle {
+class AvbHandle {
   public:
-    // The factory method to return a FsManagerAvbUniquePtr that holds
+    // The factory method to return a AvbUniquePtr that holds
     // the verified AVB (external/avb) metadata of all verified partitions
     // in avb_slot_data_.vbmeta_images[].
     //
@@ -51,7 +49,7 @@
     //   - androidboot.vbmeta.{hash_alg, size, digest}.
     //
     // A typical usage will be:
-    //   - FsManagerAvbUniquePtr handle = FsManagerAvbHandle::Open();
+    //   - AvbUniquePtr handle = AvbHandle::Open();
     //
     // Possible return values:
     //   - nullptr: any error when reading and verifying the metadata,
@@ -75,7 +73,7 @@
     //   - a valid unique_ptr with status kAvbHandleSuccess: the metadata
     //     is verified and can be trusted.
     //
-    static FsManagerAvbUniquePtr Open();
+    static AvbUniquePtr Open();
 
     // Sets up dm-verity on the given fstab entry.
     // The 'wait_for_verity_dev' parameter makes this function wait for the
@@ -87,17 +85,17 @@
     //     failed to get the HASHTREE descriptor, runtime error when set up
     //     device-mapper, etc.
     //   - kDisabled: hashtree is disabled.
-    SetUpAvbHashtreeResult SetUpAvbHashtree(fstab_rec* fstab_entry, bool wait_for_verity_dev);
+    AvbHashtreeResult SetUpAvbHashtree(fstab_rec* fstab_entry, bool wait_for_verity_dev);
 
     const std::string& avb_version() const { return avb_version_; }
 
-    FsManagerAvbHandle(const FsManagerAvbHandle&) = delete;             // no copy
-    FsManagerAvbHandle& operator=(const FsManagerAvbHandle&) = delete;  // no assignment
+    AvbHandle(const AvbHandle&) = delete;             // no copy
+    AvbHandle& operator=(const AvbHandle&) = delete;  // no assignment
 
-    FsManagerAvbHandle(FsManagerAvbHandle&&) noexcept = delete;             // no move
-    FsManagerAvbHandle& operator=(FsManagerAvbHandle&&) noexcept = delete;  // no move assignment
+    AvbHandle(AvbHandle&&) noexcept = delete;             // no move
+    AvbHandle& operator=(AvbHandle&&) noexcept = delete;  // no move assignment
 
-    ~FsManagerAvbHandle() {
+    ~AvbHandle() {
         if (avb_slot_data_) {
             avb_slot_verify_data_free(avb_slot_data_);
         }
@@ -112,11 +110,12 @@
         kAvbHandleVerificationError,
     };
 
-    FsManagerAvbHandle() : avb_slot_data_(nullptr), status_(kAvbHandleUninitialized) {}
+    AvbHandle() : avb_slot_data_(nullptr), status_(kAvbHandleUninitialized) {}
 
     AvbSlotVerifyData* avb_slot_data_;
     AvbHandleStatus status_;
     std::string avb_version_;
 };
 
-#endif /* __CORE_FS_MGR_AVB_H */
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/fs_mgr_priv_sha.h b/fs_mgr/libfs_avb/sha.h
similarity index 92%
rename from fs_mgr/fs_mgr_priv_sha.h
rename to fs_mgr/libfs_avb/sha.h
index 5b53eea..2d3ca6d 100644
--- a/fs_mgr/fs_mgr_priv_sha.h
+++ b/fs_mgr/libfs_avb/sha.h
@@ -14,11 +14,13 @@
  * limitations under the License.
  */
 
-#ifndef __CORE_FS_MGR_PRIV_SHA_H
-#define __CORE_FS_MGR_PRIV_SHA_H
+#pragma once
 
 #include <openssl/sha.h>
 
+namespace android {
+namespace fs_mgr {
+
 class SHA256Hasher {
   private:
     SHA256_CTX sha256_ctx;
@@ -59,4 +61,5 @@
     }
 };
 
-#endif /* __CORE_FS_MGR_PRIV_SHA_H */
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index da86d75..07f9d66 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -578,6 +578,12 @@
     CHECK_NE(sectors_per_block, 0);
     CHECK(sectors_needed % sectors_per_block == 0);
 
+    if (IsABDevice() && !IsRetrofitDevice() && GetPartitionSlotSuffix(partition->name()) == "_b") {
+        // Allocate "a" partitions top-down and "b" partitions bottom-up, to
+        // minimize fragmentation during OTA.
+        free_regions = PrioritizeSecondHalfOfSuper(free_regions);
+    }
+
     // Find gaps that we can use for new extents. Note we store new extents in a
     // temporary vector, and only commit them if we are guaranteed enough free
     // space.
@@ -600,14 +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();
@@ -621,6 +636,40 @@
     return true;
 }
 
+std::vector<MetadataBuilder::Interval> MetadataBuilder::PrioritizeSecondHalfOfSuper(
+        const std::vector<Interval>& free_list) {
+    const auto& super = block_devices_[0];
+    uint64_t first_sector = super.first_logical_sector;
+    uint64_t last_sector = super.size / LP_SECTOR_SIZE;
+    uint64_t midpoint = first_sector + (last_sector - first_sector) / 2;
+
+    // Choose an aligned sector for the midpoint. This could lead to one half
+    // being slightly larger than the other, but this will not restrict the
+    // size of partitions (it might lead to one extra extent if "B" overflows).
+    midpoint = AlignSector(super, midpoint);
+
+    std::vector<Interval> first_half;
+    std::vector<Interval> second_half;
+    for (const auto& region : free_list) {
+        // Note: deprioritze if not the main super partition. Even though we
+        // don't call this for retrofit devices, we will allow adding additional
+        // block devices on non-retrofit devices.
+        if (region.device_index != 0 || region.end <= midpoint) {
+            first_half.emplace_back(region);
+            continue;
+        }
+        if (region.start < midpoint && region.end > midpoint) {
+            // Split this into two regions.
+            first_half.emplace_back(region.device_index, region.start, midpoint);
+            second_half.emplace_back(region.device_index, midpoint, region.end);
+        } else {
+            second_half.emplace_back(region);
+        }
+    }
+    second_half.insert(second_half.end(), first_half.begin(), first_half.end());
+    return second_half;
+}
+
 void MetadataBuilder::ShrinkPartition(Partition* partition, uint64_t aligned_size) {
     partition->ShrinkTo(aligned_size);
 }
@@ -930,5 +979,9 @@
     return android::base::GetBoolProperty("ro.build.ab_update", false);
 }
 
+bool MetadataBuilder::IsRetrofitDevice() const {
+    return GetBlockDevicePartitionName(block_devices_[0]) != LP_METADATA_DEFAULT_PARTITION_NAME;
+}
+
 }  // namespace fs_mgr
 }  // namespace android
diff --git a/fs_mgr/liblp/builder_test.cpp b/fs_mgr/liblp/builder_test.cpp
index 926fe12..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);
@@ -720,3 +720,65 @@
     ASSERT_EQ(builder->AddPartition("system", 0), nullptr);
     ASSERT_NE(builder->AddPartition("system_a", 0), nullptr);
 }
+
+TEST_F(BuilderTest, ABExtents) {
+    BlockDeviceInfo device_info("super", 10_GiB, 768 * 1024, 0, 4096);
+
+    // A and B slots should be allocated from separate halves of the partition,
+    // to mitigate allocating too many extents. (b/120433288)
+    MetadataBuilder::OverrideABForTesting(true);
+    auto builder = MetadataBuilder::New(device_info, 65536, 2);
+    ASSERT_NE(builder, nullptr);
+    Partition* system_a = builder->AddPartition("system_a", 0);
+    ASSERT_NE(system_a, nullptr);
+    Partition* system_b = builder->AddPartition("system_b", 0);
+    ASSERT_NE(system_b, nullptr);
+    ASSERT_TRUE(builder->ResizePartition(system_a, 2_GiB));
+    ASSERT_TRUE(builder->ResizePartition(system_b, 2_GiB));
+
+    builder->RemovePartition("system_a");
+    system_a = builder->AddPartition("system_a", 0);
+    ASSERT_NE(system_a, nullptr);
+    ASSERT_TRUE(builder->ResizePartition(system_a, 3_GiB));
+
+    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>(2));
+
+    unique_ptr<LpMetadata> exported = builder->Export();
+    ASSERT_NE(exported, nullptr);
+    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, 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/include/liblp/builder.h b/fs_mgr/liblp/include/liblp/builder.h
index 4bb38d6..f477b4b 100644
--- a/fs_mgr/liblp/include/liblp/builder.h
+++ b/fs_mgr/liblp/include/liblp/builder.h
@@ -275,6 +275,7 @@
                        const LpMetadataPartition& source);
     bool ImportPartition(const LpMetadata& metadata, const LpMetadataPartition& source);
     bool IsABDevice() const;
+    bool IsRetrofitDevice() const;
 
     struct Interval {
         uint32_t device_index;
@@ -294,6 +295,7 @@
     std::vector<Interval> GetFreeRegions() const;
     void ExtentsToFreeList(const std::vector<Interval>& extents,
                            std::vector<Interval>* free_regions) const;
+    std::vector<Interval> PrioritizeSecondHalfOfSuper(const std::vector<Interval>& free_list);
 
     static bool sABOverrideValue;
     static bool sABOverrideSet;
diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index 7a00194..561debb 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -27,6 +27,7 @@
 GREEN="${ESCAPE}[38;5;40m"
 RED="${ESCAPE}[38;5;196m"
 ORANGE="${ESCAPE}[38;5;255:165:0m"
+BLUE="${ESCAPE}[35m"
 NORMAL="${ESCAPE}[0m"
 
 # Helper functions
@@ -63,6 +64,7 @@
 
 Returns: the logcat output" ]
 adb_logcat() {
+  echo "${RED}[     INFO ]${NORMAL} logcat ${@}" >&2 &&
   adb logcat "${@}" </dev/null |
     grep -v 'logd    : logdr: UID=' |
     sed -e '${/------- beginning of kernel/d}' -e 's/^[0-1][0-9]-[0-3][0-9] //'
@@ -106,12 +108,13 @@
 
 Returns: true if the reboot command succeeded" ]
 adb_reboot() {
-  adb reboot remount-test
+  adb reboot remount-test &&
+  sleep 2
 }
 
 [ "USAGE: adb_wait [timeout]
 
-Returns: waits until the device has returned or the optional timeout" ]
+Returns: waits until the device has returned for adb or optional timeout" ]
 adb_wait() {
   if [ -n "${1}" ]; then
     timeout --preserve-status --signal=KILL ${1} adb wait-for-device
@@ -120,24 +123,71 @@
   fi
 }
 
+[ "USAGE: fastboot_wait [timeout]
+
+Returns: waits until the device has returned for fastboot or optional timeout" ]
+fastboot_wait() {
+  # fastboot has no wait-for-device, but it does an automatic
+  # wait and requires (even a nonsensical) command to do so.
+  if [ -n "${1}" ]; then
+    timeout --preserve-status --signal=KILL ${1} fastboot wait-for-device
+  else
+    fastboot wait-for-device >/dev/null
+  fi >/dev/null 2>/dev/null ||
+    inFastboot
+}
+
 [ "USAGE: adb_root
 
+NB: This can be flakey on devices due to USB state
+
 Returns: true if device in root state" ]
 adb_root() {
-  adb root >/dev/null </dev/null 2>/dev/null &&
-  sleep 1 &&
-  adb_wait &&
-  sleep 1
+  adb root >/dev/null </dev/null 2>/dev/null
+  sleep 2
+  adb_wait 2m &&
+    [ `adb_sh echo '${USER}'` = root ]
 }
 
-[ "USAGE: die [-t <epoch>] [message] >/dev/stderr
+[ "USAGE: fastboot_getvar var expected
 
-If -t <epoch> argument is supplied, dump logcat.
+Returns: true if var output matches expected" ]
+fastboot_getvar() {
+  O=`fastboot getvar ${1} 2>&1`
+  err=${?}
+  O="${O#< waiting for * >?}"
+  O="${O%%?Finished. Total time: *}"
+  if [ 0 -ne ${err} ]; then
+    echo ${O} >&2
+    false
+    return
+  fi
+  if [ "${O}" != "${O#*FAILED}" ]; then
+    O="${1}: <empty>"
+  fi
+  if [ -n "${2}" -a "${1}: ${2}" != "${O}" ]; then
+    echo "${2} != ${O}" >&2
+    false
+    return
+  fi
+  echo ${O} >&2
+}
+
+[ "USAGE: die [-d|-t <epoch>] [message] >/dev/stderr
+
+If -d, or -t <epoch> argument is supplied, dump logcat.
 
 Returns: exit failure, report status" ]
 die() {
-  if [ X"-t" = X"${1}" -a -n "${2}" ]; then
-    adb_logcat -b all -v nsec -t ${2} >&2
+  if [ X"-d" = X"${1}" ]; then
+    adb_logcat -b all -v nsec -d >&2
+    shift
+  elif [ X"-t" = X"${1}" ]; then
+    if [ -n "${2}" ]; then
+      adb_logcat -b all -v nsec -t ${2} >&2
+    else
+      adb_logcat -b all -v nsec -d >&2
+    fi
     shift 2
   fi
   echo "${RED}[  FAILED  ]${NORMAL} ${@}" >&2
@@ -201,15 +251,20 @@
     die "${@}"
 }
 
-[ "USAGE: skip_administrative_mounts < /proc/mounts
+[ "USAGE: skip_administrative_mounts [data] < /proc/mounts
 
 Filters out all administrative (eg: sysfs) mounts uninteresting to the test" ]
 skip_administrative_mounts() {
+  if [ "data" = "${1}" ]; then
+    grep -v " /data "
+  else
+    cat -
+  fi |
   grep -v \
     -e "^\(overlay\|tmpfs\|none\|sysfs\|proc\|selinuxfs\|debugfs\) " \
     -e "^\(bpf\|cg2_bpf\|pstore\|tracefs\|adb\|mtp\|ptp\|devpts\) " \
     -e "^\(/data/media\|/dev/block/loop[0-9]*\) " \
-    -e " /\(cache\|mnt/scratch\|mnt/vendor/persist\|metadata\|data\) "
+    -e " /\(cache\|mnt/scratch\|mnt/vendor/persist\|metadata\) "
 }
 
 if [ X"-s" = X"${1}" -a -n "${2}" ]; then
@@ -226,6 +281,9 @@
 isDebuggable || die "device not a debug build"
 
 # Do something
+
+echo "${GREEN}[ RUN      ]${NORMAL} Testing kernel support for overlayfs" >&2
+
 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 ||
@@ -233,9 +291,11 @@
 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"
-adb_root &&
-  adb_wait ||
+adb_root ||
   die "initial setup"
+
+echo "${GREEN}[ RUN      ]${NORMAL} Checking current overlayfs status" >&2
+
 reboot=false
 OVERLAYFS_BACKING="cache mnt/scratch"
 for d in ${OVERLAYFS_BACKING}; do
@@ -250,8 +310,7 @@
   echo "${ORANGE}[  WARNING ]${NORMAL} rebooting before test" >&2
   adb_reboot &&
     adb_wait 2m &&
-    adb_root &&
-    adb_wait ||
+    adb_root ||
     die "reboot after wipe"
 fi
 D=`adb_sh df -k </dev/null` &&
@@ -262,65 +321,95 @@
   echo "${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 |
+                skip_administrative_mounts data |
                 cut -s -d' ' -f1`
 
+echo "${GREEN}[ RUN      ]${NORMAL} disable verity" >&2
+
 T=`adb_date`
 D=`adb disable-verity 2>&1`
 err=${?}
-echo "${D}"
 if [ ${err} != 0 -o X"${D}" != X"${D##*setup failed}" ]; then
+  echo "${D%?Now reboot your device for settings to take effect}"
   die -t ${T} "setup for overlay"
 fi
 if [ X"${D}" != X"${D##*using overlayfs}" ]; then
   echo "${GREEN}[       OK ]${NORMAL} using overlayfs" >&2
 fi
-adb_reboot &&
-  adb_wait &&
-  D=`adb_sh df -k </dev/null` &&
-  H=`echo "${D}" | head -1` &&
-  D=`echo "${D}" | grep "^overlay "` &&
-  echo "${H}" &&
-  echo "${D}" ||
-  die "overlay takeover failed"
-echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
-  echo "${ORANGE}[  WARNING ]${NORMAL} overlay takeover before remount not complete" >&2
-
-T=`adb_date`
-adb_root &&
-  adb_wait &&
-  adb remount &&
-  D=`adb_sh df -k </dev/null` ||
-  die -t ${T} "can not collect filesystem data"
-if echo "${D}" | grep " /mnt/scratch" >/dev/null; then
-  echo "${ORANGE}[     INFO ]${NORMAL} using scratch dynamic partition for overrides" >&2
-  H=`adb_sh cat /proc/mounts | sed -n 's@\([^ ]*\) /mnt/scratch \([^ ]*\) .*@\2 on \1@p'`
-  [ -n "${H}" ] &&
-    echo "${ORANGE}[     INFO ]${NORMAL} scratch filesystem ${H}"
+reboot=false
+if [ X"${D}" != X"${D##*Successfully disabled verity}" ]; then
+  echo "${GREEN}[       OK ]${NORMAL} disabled verity" >&2
+  reboot=true
+else
+  echo "${ORANGE}[  WARNING ]${NORMAL} verity already disabled" >&2
 fi
+D=`adb_sh df -k </dev/null` &&
+  H=`echo "${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
+  L=`adb_logcat -b all -v nsec -t ${T} 2>&1`
+  adb_reboot &&
+    adb_wait 2m ||
+    die "reboot after verity disabled failed"
+  T=
+fi
+
+echo "${GREEN}[ RUN      ]${NORMAL} remount" >&2
+
+adb_root &&
+  adb remount ||
+  ( [ -n "${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 "${ORANGE}[     INFO ]${NORMAL} /${d}/overlay is setup" >&2
+    echo "${BLUE}[     INFO ]${NORMAL} /${d}/overlay is setup" >&2
   fi
 done
 
-H=`echo "${D}" | head -1` &&
-  D=`echo "${D}" | grep "^overlay "` &&
-  echo "${H}" &&
+echo "${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) ||
+  !(adb_sh grep " rw," /proc/mounts </dev/null | skip_administrative_mounts data) ||
   die "remount overlayfs missed a spot (ro)"
 
-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
-
 # Check something
+
+echo "${GREEN}[ RUN      ]${NORMAL} push content to system and vendor" >&2
+
 A="Hello World! $(date)"
 echo "${A}" | adb_sh "cat - > /system/hello"
 echo "${A}" | adb_sh "cat - > /vendor/hello"
@@ -330,9 +419,26 @@
 B="`adb_cat /vendor/hello`" ||
   die "vendor hello"
 check_eq "${A}" "${B}" vendor before reboot
+
+echo "${GREEN}[ RUN      ]${NORMAL} reboot to confirm content persistent" >&2
+
 adb_reboot &&
-  adb_wait &&
-  B="`adb_cat /system/hello`" ||
+  adb_wait 2m ||
+  die "reboot after override content added failed"
+
+D=`adb_su df -k </dev/null` &&
+  H=`echo "${D}" | head -1` &&
+  D=`echo "${D}" | grep "^overlay "` ||
+  ( echo "${L}" && false ) ||
+  die -d "overlay takeover failed after reboot"
+
+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
+
+B="`adb_cat /system/hello`" ||
   die "re-read system hello after reboot"
 check_eq "${A}" "${B}" system after reboot
 # Only root can read vendor if sepolicy permissions are as expected
@@ -340,19 +446,52 @@
   die "re-read vendor hello after reboot w/o root"
 check_eq "cat: /vendor/hello: Permission denied" "${B}" vendor after reboot w/o root
 adb_root &&
-  adb_wait &&
   B="`adb_cat /vendor/hello`" ||
   die "re-read vendor hello after reboot"
 check_eq "${A}" "${B}" vendor after reboot
 
-adb reboot-fastboot &&
-  fastboot flash vendor &&
-  fastboot reboot ||
-  die "fastbootd flash vendor"
+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 ${scratch_partition} parameters"
+else
+  fastboot_getvar is-logical:${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 ${scratch_partition}"
+fastboot reboot ||
+  die "can not reboot out of fastboot"
+echo "${ORANGE}[  WARNING ]${NORMAL} adb after fastboot ... waiting 2 minutes"
 adb_wait 2m ||
   die "did not reboot after flash"
 adb_root &&
-  adb_wait &&
   D=`adb_sh df -k </dev/null` &&
   H=`echo "${D}" | head -1` &&
   D=`echo "${D}" | grep "^overlay "` &&
@@ -365,13 +504,14 @@
 B="`adb_cat /system/hello`" ||
   die "re-read system hello after flash vendor"
 check_eq "${A}" "${B}" system after flash vendor
-adb_root &&
-  adb_wait ||
+adb_root ||
   die "adb root"
 B="`adb_cat /vendor/hello`" &&
   die "re-read vendor hello after flash vendor"
 check_eq "cat: /vendor/hello: No such file or directory" "${B}" vendor after flash vendor
 
+echo "${GREEN}[ RUN      ]${NORMAL} remove test content (cleanup)" >&2
+
 T=`adb_date`
 adb remount &&
   ( adb_sh rm /vendor/hello </dev/null 2>/dev/null || true ) &&
@@ -384,4 +524,32 @@
   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
+
+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}[  PASSED  ]${NORMAL} adb remount" >&2
diff --git a/init/Android.bp b/init/Android.bp
index ff3b61f..e7b8516 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -19,6 +19,7 @@
     cpp_std: "experimental",
     sanitize: {
         misc_undefined: ["signed-integer-overflow"],
+        address: false,  // TODO(b/120561310): Fix ASAN to work without /proc mounted and re-enable.
     },
     cflags: [
         "-DLOG_UEVENTS=0",
@@ -71,6 +72,7 @@
         "libbinder",
         "libbootloader_message",
         "libcutils",
+        "libcrypto",
         "libdl",
         "libext4_utils",
         "libfs_mgr",
@@ -79,6 +81,7 @@
         "libkeyutils",
         "liblog",
         "liblogwrap",
+        "liblp",
         "libselinux",
         "libutils",
     ],
@@ -92,6 +95,7 @@
         "action.cpp",
         "action_manager.cpp",
         "action_parser.cpp",
+        "boringssl_self_test.cpp",
         "bootchart.cpp",
         "builtins.cpp",
         "capabilities.cpp",
@@ -99,6 +103,7 @@
         "devices.cpp",
         "epoll.cpp",
         "firmware_handler.cpp",
+        "first_stage_init.cpp",
         "first_stage_mount.cpp",
         "import_parser.cpp",
         "init.cpp",
@@ -117,6 +122,7 @@
         "sigchld_handler.cpp",
         "subcontext.cpp",
         "subcontext.proto",
+        "switch_root.cpp",
         "rlimit_parser.cpp",
         "tokenizer.cpp",
         "uevent_listener.cpp",
diff --git a/init/Android.mk b/init/Android.mk
index dc46d21..bdd0301 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -35,16 +35,18 @@
     -Wall -Wextra \
     -Wno-unused-parameter \
     -Werror \
-    -std=gnu++1z \
 
 # --
 
+# Do not build this even with mmma if we're system-as-root, otherwise it will overwrite the symlink.
+ifneq ($(BOARD_BUILD_SYSTEM_ROOT_IMAGE),true)
 include $(CLEAR_VARS)
 LOCAL_CPPFLAGS := $(init_cflags)
 LOCAL_SRC_FILES := \
     devices.cpp \
+    first_stage_init.cpp \
+    first_stage_main.cpp \
     first_stage_mount.cpp \
-    init_first_stage.cpp \
     reboot_utils.cpp \
     selinux.cpp \
     switch_root.cpp \
@@ -67,6 +69,7 @@
     $(TARGET_RAMDISK_OUT)/sys \
 
 LOCAL_STATIC_LIBRARIES := \
+    libfs_avb \
     libfs_mgr \
     libfec \
     libfec_rs \
@@ -93,20 +96,14 @@
 # First stage init is weird: it may start without stdout/stderr, and no /proc.
 LOCAL_NOSANITIZE := hwaddress
 include $(BUILD_EXECUTABLE)
+endif
 
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := init_system
-ifeq ($(BOARD_BUILD_SYSTEM_ROOT_IMAGE),true)
-LOCAL_REQUIRED_MODULES := \
-   init_first_stage \
-   init_second_stage \
-
-else
 LOCAL_REQUIRED_MODULES := \
    init_second_stage \
 
-endif
 include $(BUILD_PHONY_PACKAGE)
 
 include $(CLEAR_VARS)
@@ -118,5 +115,3 @@
 
 endif
 include $(BUILD_PHONY_PACKAGE)
-
-
diff --git a/init/boringssl_self_test.cpp b/init/boringssl_self_test.cpp
new file mode 100644
index 0000000..0408d30
--- /dev/null
+++ b/init/boringssl_self_test.cpp
@@ -0,0 +1,56 @@
+/*
+ * 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 "boringssl_self_test.h"
+
+#include <android-base/logging.h>
+#include <cutils/android_reboot.h>
+#include <openssl/crypto.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+namespace android {
+namespace init {
+
+Result<Success> StartBoringSslSelfTest(const BuiltinArguments&) {
+    pid_t id = fork();
+
+    if (id == 0) {
+        if (BORINGSSL_self_test() != 1) {
+            LOG(INFO) << "BoringSSL crypto self tests failed";
+
+            // This check has failed, so the device should refuse
+            // to boot. Rebooting to bootloader to wait for
+            // further action from the user.
+
+            int result = android_reboot(ANDROID_RB_RESTART2, 0,
+                                        "bootloader,boringssl-self-check-failed");
+            if (result != 0) {
+                LOG(ERROR) << "Failed to reboot into bootloader";
+            }
+        }
+
+        _exit(0);
+    } else if (id == -1) {
+        // Failed to fork, so cannot run the test. Refuse to continue.
+        PLOG(FATAL) << "Failed to fork for BoringSSL self test";
+    }
+
+    return Success();
+}
+
+}  // namespace init
+}  // namespace android
diff --git a/init/boringssl_self_test.h b/init/boringssl_self_test.h
new file mode 100644
index 0000000..b21fc78
--- /dev/null
+++ b/init/boringssl_self_test.h
@@ -0,0 +1,28 @@
+/*
+ * 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 "builtin_arguments.h"
+#include "result.h"
+
+namespace android {
+namespace init {
+
+Result<Success> StartBoringSslSelfTest(const BuiltinArguments&);
+
+}  // namespace init
+}  // namespace android
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 6eb65b2..2bebe76 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -612,14 +612,15 @@
 }
 
 static Result<Success> do_swapon_all(const BuiltinArguments& args) {
-    struct fstab *fstab;
-    int ret;
+    Fstab fstab;
+    if (!ReadFstabFromFile(args[1], &fstab)) {
+        return Error() << "Could not read fstab '" << args[1] << "'";
+    }
 
-    fstab = fs_mgr_read_fstab(args[1].c_str());
-    ret = fs_mgr_swapon_all(fstab);
-    fs_mgr_free_fstab(fstab);
+    if (!fs_mgr_swapon_all(fstab)) {
+        return Error() << "fs_mgr_swapon_all() failed";
+    }
 
-    if (ret != 0) return Error() << "fs_mgr_swapon_all() failed";
     return Success();
 }
 
@@ -733,13 +734,10 @@
     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/init_first_stage.cpp b/init/first_stage_init.cpp
similarity index 97%
rename from init/init_first_stage.cpp
rename to init/first_stage_init.cpp
index c2c6868..e11d897 100644
--- a/init/init_first_stage.cpp
+++ b/init/first_stage_init.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#include "first_stage_init.h"
+
 #include <dirent.h>
 #include <fcntl.h>
 #include <paths.h>
@@ -94,7 +96,7 @@
 
 }  // namespace
 
-int main(int argc, char** argv) {
+int FirstStageMain(int argc, char** argv) {
     if (REBOOT_BOOTLOADER_ON_PANIC) {
         InstallRebootSignalHandlers();
     }
@@ -214,7 +216,7 @@
     setenv("INIT_STARTED_AT", std::to_string(start_ms).c_str(), 1);
 
     const char* path = "/system/bin/init";
-    const char* args[] = {path, nullptr};
+    const char* args[] = {path, "selinux_setup", nullptr};
     execv(path, const_cast<char**>(args));
 
     // execv() only returns if an error happened, in which case we
@@ -226,7 +228,3 @@
 
 }  // namespace init
 }  // namespace android
-
-int main(int argc, char** argv) {
-    return android::init::main(argc, argv);
-}
diff --git a/init/first_stage_init.h b/init/first_stage_init.h
new file mode 100644
index 0000000..0476e44
--- /dev/null
+++ b/init/first_stage_init.h
@@ -0,0 +1,25 @@
+/*
+ * 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
+
+namespace android {
+namespace init {
+
+int FirstStageMain(int argc, char** argv);
+
+}  // namespace init
+}  // namespace android
diff --git a/init/first_stage_main.cpp b/init/first_stage_main.cpp
new file mode 100644
index 0000000..7bae84c
--- /dev/null
+++ b/init/first_stage_main.cpp
@@ -0,0 +1,21 @@
+/*
+ * 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 "first_stage_init.h"
+
+int main(int argc, char** argv) {
+    return android::init::FirstStageMain(argc, argv);
+}
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index 43b2ebf..6ae1123 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -30,8 +30,8 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/strings.h>
+#include <fs_avb/fs_avb.h>
 #include <fs_mgr.h>
-#include <fs_mgr_avb.h>
 #include <fs_mgr_dm_linear.h>
 #include <fs_mgr_overlayfs.h>
 #include <liblp/liblp.h>
@@ -43,6 +43,9 @@
 #include "util.h"
 
 using android::base::Timer;
+using android::fs_mgr::AvbHandle;
+using android::fs_mgr::AvbHashtreeResult;
+using android::fs_mgr::AvbUniquePtr;
 
 using namespace std::literals;
 
@@ -81,7 +84,7 @@
 
     bool need_dm_verity_;
 
-    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> device_tree_fstab_;
+    std::unique_ptr<fstab, decltype(&fs_mgr_free_fstab)> fstab_;
     std::string lp_metadata_partition_;
     std::vector<fstab_rec*> mount_fstab_recs_;
     std::set<std::string> required_devices_partition_names_;
@@ -113,7 +116,7 @@
     bool InitAvbHandle();
 
     std::string device_tree_vbmeta_parts_;
-    FsManagerAvbUniquePtr avb_handle_;
+    AvbUniquePtr avb_handle_;
 };
 
 // Static Functions
@@ -129,15 +132,29 @@
 // Class Definitions
 // -----------------
 FirstStageMount::FirstStageMount()
-    : need_dm_verity_(false), device_tree_fstab_(fs_mgr_read_fstab_dt(), fs_mgr_free_fstab) {
-    if (device_tree_fstab_) {
-        // Stores device_tree_fstab_->recs[] into mount_fstab_recs_ (vector<fstab_rec*>)
-        // for easier manipulation later, e.g., range-base for loop.
-        for (int i = 0; i < device_tree_fstab_->num_entries; i++) {
-            mount_fstab_recs_.push_back(&device_tree_fstab_->recs[i]);
+    : 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 {
-        LOG(INFO) << "Failed to read fstab from device tree";
+        // 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]);
+                }
+            }
+        } else {
+            LOG(INFO) << "Failed to read fstab from device tree";
+        }
     }
 
     auto boot_devices = fs_mgr_get_boot_devices();
@@ -249,9 +266,10 @@
 }
 
 bool FirstStageMount::InitDmLinearBackingDevices(const android::fs_mgr::LpMetadata& metadata) {
-    auto partition_names = GetBlockDevicePartitionNames(metadata);
+    auto partition_names = android::fs_mgr::GetBlockDevicePartitionNames(metadata);
     for (const auto& partition_name : partition_names) {
-        if (partition_name == lp_metadata_partition_) {
+        const auto super_device = android::fs_mgr::GetMetadataSuperBlockDevice(metadata);
+        if (partition_name == android::fs_mgr::GetBlockDevicePartitionName(*super_device)) {
             continue;
         }
         required_devices_partition_names_.emplace(partition_name);
@@ -289,7 +307,7 @@
     if (!InitDmLinearBackingDevices(*metadata.get())) {
         return false;
     }
-    return android::fs_mgr::CreateLogicalPartitions(*metadata.get());
+    return android::fs_mgr::CreateLogicalPartitions(*metadata.get(), lp_metadata_partition_);
 }
 
 ListenerAction FirstStageMount::HandleBlockDevice(const std::string& name, const Uevent& uevent) {
@@ -408,12 +426,19 @@
     }
 
     // heads up for instantiating required device(s) for overlayfs logic
-    const auto devices = fs_mgr_overlayfs_required_devices(device_tree_fstab_.get());
+    const auto devices = fs_mgr_overlayfs_required_devices(mount_fstab_recs_);
     for (auto const& device : devices) {
-        InitMappedDevice(device);
+        if (android::base::StartsWith(device, "/dev/block/by-name/")) {
+            required_devices_partition_names_.emplace(basename(device.c_str()));
+            auto uevent_callback = [this](const Uevent& uevent) { return UeventCallback(uevent); };
+            uevent_listener_.RegenerateUevents(uevent_callback);
+            uevent_listener_.Poll(uevent_callback, 10s);
+        } else {
+            InitMappedDevice(device);
+        }
     }
 
-    fs_mgr_overlayfs_mount_all(device_tree_fstab_.get());
+    fs_mgr_overlayfs_mount_all(mount_fstab_recs_);
 
     return true;
 }
@@ -449,7 +474,9 @@
     // 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_) {
-        required_devices_partition_names_.emplace(basename(fstab_rec->blk_device));
+        if (!fs_mgr_is_logical(fstab_rec)) {
+            required_devices_partition_names_.emplace(basename(fstab_rec->blk_device));
+        }
     }
 
     if (!verity_loc_device.empty()) {
@@ -545,12 +572,12 @@
 bool FirstStageMountVBootV2::SetUpDmVerity(fstab_rec* fstab_rec) {
     if (fs_mgr_is_avb(fstab_rec)) {
         if (!InitAvbHandle()) return false;
-        SetUpAvbHashtreeResult hashtree_result =
+        AvbHashtreeResult hashtree_result =
                 avb_handle_->SetUpAvbHashtree(fstab_rec, false /* wait_for_verity_dev */);
         switch (hashtree_result) {
-            case SetUpAvbHashtreeResult::kDisabled:
+            case AvbHashtreeResult::kDisabled:
                 return true;  // Returns true to mount the partition.
-            case SetUpAvbHashtreeResult::kSuccess:
+            case AvbHashtreeResult::kSuccess:
                 // 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.
@@ -565,10 +592,10 @@
 bool FirstStageMountVBootV2::InitAvbHandle() {
     if (avb_handle_) return true;  // Returns true if the handle is already initialized.
 
-    avb_handle_ = FsManagerAvbHandle::Open();
+    avb_handle_ = AvbHandle::Open();
 
     if (!avb_handle_) {
-        PLOG(ERROR) << "Failed to open FsManagerAvbHandle";
+        PLOG(ERROR) << "Failed to open AvbHandle";
         return false;
     }
     // Sets INIT_AVB_VERSION here for init to set ro.boot.avb_version in the second stage.
@@ -605,7 +632,7 @@
         return;
     }
 
-    // Initializes required devices for the subsequent FsManagerAvbHandle::Open()
+    // Initializes required devices for the subsequent AvbHandle::Open()
     // to verify AVB metadata on all partitions in the verified chain.
     // We only set INIT_AVB_VERSION when the AVB verification succeeds, i.e., the
     // Open() function returns a valid handle.
@@ -616,9 +643,9 @@
         return;
     }
 
-    FsManagerAvbUniquePtr avb_handle = FsManagerAvbHandle::Open();
+    AvbUniquePtr avb_handle = AvbHandle::Open();
     if (!avb_handle) {
-        PLOG(ERROR) << "Failed to open FsManagerAvbHandle for INIT_AVB_VERSION";
+        PLOG(ERROR) << "Failed to open AvbHandle for INIT_AVB_VERSION";
         return;
     }
     setenv("INIT_AVB_VERSION", avb_handle->avb_version().c_str(), 1);
diff --git a/init/init.cpp b/init/init.cpp
index e7dbc11..dc46a82 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -49,6 +49,7 @@
 #endif
 
 #include "action_parser.h"
+#include "boringssl_self_test.h"
 #include "epoll.h"
 #include "first_stage_mount.h"
 #include "import_parser.h"
@@ -59,13 +60,8 @@
 #include "security.h"
 #include "selinux.h"
 #include "sigchld_handler.h"
-#include "ueventd.h"
 #include "util.h"
 
-#if __has_feature(address_sanitizer)
-#include <sanitizer/asan_interface.h>
-#endif
-
 using namespace std::chrono_literals;
 using namespace std::string_literals;
 
@@ -79,25 +75,6 @@
 namespace android {
 namespace init {
 
-#if __has_feature(address_sanitizer)
-// Load asan.options if it exists since these are not yet in the environment.
-// Always ensure detect_container_overflow=0 as there are false positives with this check.
-// Always ensure abort_on_error=1 to ensure we reboot to bootloader for development builds.
-extern "C" const char* __asan_default_options() {
-    return "include_if_exists=/system/asan.options:detect_container_overflow=0:abort_on_error=1";
-}
-
-__attribute__((no_sanitize("address", "memory", "thread", "undefined"))) extern "C" void
-__sanitizer_report_error_summary(const char* summary) {
-    LOG(ERROR) << "Main stage (error summary): " << summary;
-}
-
-__attribute__((no_sanitize("address", "memory", "thread", "undefined"))) static void
-AsanReportCallback(const char* str) {
-    LOG(ERROR) << "Main stage: " << str;
-}
-#endif
-
 static int property_triggers_enabled = 0;
 
 static char qemu[32];
@@ -622,57 +599,11 @@
     });
 }
 
-static void SetupSelinux(char** argv) {
-    android::base::InitLogging(argv, &android::base::KernelLogger, [](const char*) {
-        RebootSystem(ANDROID_RB_RESTART2, "bootloader");
-    });
-
-    // Set up SELinux, loading the SELinux policy.
-    SelinuxSetupKernelLogging();
-    SelinuxInitialize();
-
-    // We're in the kernel domain and want to transition to the init domain.  File systems that
-    // store SELabels in their xattrs, such as ext4 do not need an explicit restorecon here,
-    // but other file systems do.  In particular, this is needed for ramdisks such as the
-    // recovery image for A/B devices.
-    if (selinux_android_restorecon("/system/bin/init", 0) == -1) {
-        PLOG(FATAL) << "restorecon failed of /system/bin/init failed";
-    }
-
-    setenv("SELINUX_INITIALIZED", "true", 1);
-
-    const char* path = "/system/bin/init";
-    const char* args[] = {path, nullptr};
-    execv(path, const_cast<char**>(args));
-
-    // execv() only returns if an error happened, in which case we
-    // panic and never return from this function.
-    PLOG(FATAL) << "execv(\"" << path << "\") failed";
-}
-
-int main(int argc, char** argv) {
-#if __has_feature(address_sanitizer)
-    __asan_set_error_report_callback(AsanReportCallback);
-#endif
-
-    if (!strcmp(basename(argv[0]), "ueventd")) {
-        return ueventd_main(argc, argv);
-    }
-
-    if (argc > 1 && !strcmp(argv[1], "subcontext")) {
-        android::base::InitLogging(argv, &android::base::KernelLogger);
-        const BuiltinFunctionMap function_map;
-        return SubcontextMain(argc, argv, &function_map);
-    }
-
+int SecondStageMain(int argc, char** argv) {
     if (REBOOT_BOOTLOADER_ON_PANIC) {
         InstallRebootSignalHandlers();
     }
 
-    if (getenv("SELINUX_INITIALIZED") == nullptr) {
-        SetupSelinux(argv);
-    }
-
     // We need to set up stdin/stdout/stderr again now that we're running in init's context.
     InitKernelLogging(argv, InitAborter);
     LOG(INFO) << "init second stage started!";
@@ -708,7 +639,6 @@
     if (avb_version) property_set("ro.boot.avb_version", avb_version);
 
     // Clean up our environment.
-    unsetenv("SELINUX_INITIALIZED");
     unsetenv("INIT_STARTED_AT");
     unsetenv("INIT_SELINUX_TOOK");
     unsetenv("INIT_AVB_VERSION");
@@ -768,6 +698,9 @@
     // Trigger all the boot actions to get us started.
     am.QueueEventTrigger("init");
 
+    // Starting the BoringSSL self test, for NIAP certification compliance.
+    am.QueueBuiltinAction(StartBoringSslSelfTest, "StartBoringSslSelfTest");
+
     // Repeat mix_hwrng_into_linux_rng in case /dev/hw_random or /dev/random
     // wasn't ready immediately after wait_for_coldboot_done
     am.QueueBuiltinAction(MixHwrngIntoLinuxRngAction, "MixHwrngIntoLinuxRng");
diff --git a/init/init.h b/init/init.h
index 65405aa..a76da20 100644
--- a/init/init.h
+++ b/init/init.h
@@ -50,7 +50,7 @@
 
 void ResetWaitForProp();
 
-int main(int argc, char** argv);
+int SecondStageMain(int argc, char** argv);
 
 }  // namespace init
 }  // namespace android
diff --git a/init/main.cpp b/init/main.cpp
index 9ed451b..868c409 100644
--- a/init/main.cpp
+++ b/init/main.cpp
@@ -14,8 +14,70 @@
  * limitations under the License.
  */
 
+#include "builtins.h"
+#include "first_stage_init.h"
 #include "init.h"
+#include "selinux.h"
+#include "subcontext.h"
+#include "ueventd.h"
+
+#include <android-base/logging.h>
+
+#if __has_feature(address_sanitizer)
+#include <sanitizer/asan_interface.h>
+#endif
+
+#if __has_feature(address_sanitizer)
+// Load asan.options if it exists since these are not yet in the environment.
+// Always ensure detect_container_overflow=0 as there are false positives with this check.
+// Always ensure abort_on_error=1 to ensure we reboot to bootloader for development builds.
+extern "C" const char* __asan_default_options() {
+    return "include_if_exists=/system/asan.options:detect_container_overflow=0:abort_on_error=1";
+}
+
+__attribute__((no_sanitize("address", "memory", "thread", "undefined"))) extern "C" void
+__sanitizer_report_error_summary(const char* summary) {
+    LOG(ERROR) << "Init (error summary): " << summary;
+}
+
+__attribute__((no_sanitize("address", "memory", "thread", "undefined"))) static void
+AsanReportCallback(const char* str) {
+    LOG(ERROR) << "Init: " << str;
+}
+#endif
+
+using namespace android::init;
 
 int main(int argc, char** argv) {
-    android::init::main(argc, argv);
+#if __has_feature(address_sanitizer)
+    __asan_set_error_report_callback(AsanReportCallback);
+#endif
+
+    if (!strcmp(basename(argv[0]), "ueventd")) {
+        return ueventd_main(argc, argv);
+    }
+
+    if (argc < 2) {
+        return FirstStageMain(argc, argv);
+    }
+
+    if (!strcmp(argv[1], "subcontext")) {
+        android::base::InitLogging(argv, &android::base::KernelLogger);
+        const BuiltinFunctionMap function_map;
+
+        return SubcontextMain(argc, argv, &function_map);
+    }
+
+    if (!strcmp(argv[1], "selinux_setup")) {
+        return SetupSelinux(argv);
+    }
+
+    if (!strcmp(argv[1], "second_stage")) {
+        return SecondStageMain(argc, argv);
+    }
+
+    android::base::InitLogging(argv, &android::base::KernelLogger);
+
+    LOG(ERROR) << "Unknown argument passed to init '" << argv[1] << "'";
+    return 1;
 }
diff --git a/init/selinux.cpp b/init/selinux.cpp
index fd7e86f..3a09096 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -18,8 +18,8 @@
 // for SELinux operation for init.
 
 // When the system boots, there is no SEPolicy present and init is running in the kernel domain.
-// Init loads the SEPolicy from the file system, restores the context of /init based on this
-// SEPolicy, and finally exec()'s itself to run in the proper domain.
+// Init loads the SEPolicy from the file system, restores the context of /system/bin/init based on
+// this SEPolicy, and finally exec()'s itself to run in the proper domain.
 
 // The SEPolicy on Android comes in two variants: monolithic and split.
 
@@ -58,8 +58,10 @@
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/unique_fd.h>
+#include <cutils/android_reboot.h>
 #include <selinux/android.h>
 
+#include "reboot_utils.h"
 #include "util.h"
 
 using android::base::ParseInt;
@@ -379,8 +381,6 @@
     return IsSplitPolicyDevice() ? LoadSplitPolicy() : LoadMonolithicPolicy();
 }
 
-}  // namespace
-
 void SelinuxInitialize() {
     Timer t;
 
@@ -405,6 +405,8 @@
     setenv("INIT_SELINUX_TOOK", std::to_string(t.duration().count()).c_str(), 1);
 }
 
+}  // namespace
+
 // The files and directories that were created before initial sepolicy load or
 // files on ramdisk need to have their security context restored to the proper
 // value. This must happen before /dev is populated by ueventd.
@@ -496,6 +498,39 @@
     return major_version;
 }
 
+// This function initializes SELinux then execs init to run in the init SELinux context.
+int SetupSelinux(char** argv) {
+    android::base::InitLogging(argv, &android::base::KernelLogger, [](const char*) {
+        RebootSystem(ANDROID_RB_RESTART2, "bootloader");
+    });
+
+    if (REBOOT_BOOTLOADER_ON_PANIC) {
+        InstallRebootSignalHandlers();
+    }
+
+    // Set up SELinux, loading the SELinux policy.
+    SelinuxSetupKernelLogging();
+    SelinuxInitialize();
+
+    // We're in the kernel domain and want to transition to the init domain.  File systems that
+    // store SELabels in their xattrs, such as ext4 do not need an explicit restorecon here,
+    // but other file systems do.  In particular, this is needed for ramdisks such as the
+    // recovery image for A/B devices.
+    if (selinux_android_restorecon("/system/bin/init", 0) == -1) {
+        PLOG(FATAL) << "restorecon failed of /system/bin/init failed";
+    }
+
+    const char* path = "/system/bin/init";
+    const char* args[] = {path, "second_stage", nullptr};
+    execv(path, const_cast<char**>(args));
+
+    // execv() only returns if an error happened, in which case we
+    // panic and never return from this function.
+    PLOG(FATAL) << "execv(\"" << path << "\") failed";
+
+    return 1;
+}
+
 // selinux_android_file_context_handle() takes on the order of 10+ms to run, so we want to cache
 // its value.  selinux_android_restorecon() also needs an sehandle for file context look up.  It
 // will create and store its own copy, but selinux_android_set_sehandle() can be used to provide
diff --git a/init/selinux.h b/init/selinux.h
index c41d7f0..3aa9406 100644
--- a/init/selinux.h
+++ b/init/selinux.h
@@ -23,7 +23,7 @@
 namespace android {
 namespace init {
 
-void SelinuxInitialize();
+int SetupSelinux(char** argv);
 void SelinuxRestoreContext();
 
 void SelinuxSetupKernelLogging();
diff --git a/init/uevent_listener.cpp b/init/uevent_listener.cpp
index 8cf2128..62cd2be 100644
--- a/init/uevent_listener.cpp
+++ b/init/uevent_listener.cpp
@@ -86,9 +86,8 @@
     }
 }
 
-UeventListener::UeventListener() {
-    // is 2MB enough? udev uses 128MB!
-    device_fd_.reset(uevent_open_socket(2 * 1024 * 1024, true));
+UeventListener::UeventListener(size_t uevent_socket_rcvbuf_size) {
+    device_fd_.reset(uevent_open_socket(uevent_socket_rcvbuf_size, true));
     if (device_fd_ == -1) {
         LOG(FATAL) << "Could not open uevent socket";
     }
diff --git a/init/uevent_listener.h b/init/uevent_listener.h
index 5b453fe..aea094e 100644
--- a/init/uevent_listener.h
+++ b/init/uevent_listener.h
@@ -41,7 +41,7 @@
 
 class UeventListener {
   public:
-    UeventListener();
+    UeventListener(size_t uevent_socket_rcvbuf_size);
 
     void RegenerateUevents(const ListenerCallback& callback) const;
     ListenerAction RegenerateUeventsForPath(const std::string& path,
diff --git a/init/ueventd.cpp b/init/ueventd.cpp
index 66491dd..7545d53 100644
--- a/init/ueventd.cpp
+++ b/init/ueventd.cpp
@@ -233,29 +233,26 @@
     SelabelInitialize();
 
     std::vector<std::unique_ptr<UeventHandler>> uevent_handlers;
-    UeventListener uevent_listener;
 
-    {
-        // Keep the current product name base configuration so we remain backwards compatible and
-        // allow it to override everything.
-        // TODO: cleanup platform ueventd.rc to remove vendor specific device node entries (b/34968103)
-        auto hardware = android::base::GetProperty("ro.hardware", "");
+    // Keep the current product name base configuration so we remain backwards compatible and
+    // allow it to override everything.
+    // TODO: cleanup platform ueventd.rc to remove vendor specific device node entries (b/34968103)
+    auto hardware = android::base::GetProperty("ro.hardware", "");
 
-        auto ueventd_configuration =
-                ParseConfig({"/ueventd.rc", "/vendor/ueventd.rc", "/odm/ueventd.rc",
-                             "/ueventd." + hardware + ".rc"});
+    auto ueventd_configuration = ParseConfig({"/ueventd.rc", "/vendor/ueventd.rc",
+                                              "/odm/ueventd.rc", "/ueventd." + hardware + ".rc"});
 
-        uevent_handlers.emplace_back(std::make_unique<DeviceHandler>(
-                std::move(ueventd_configuration.dev_permissions),
-                std::move(ueventd_configuration.sysfs_permissions),
-                std::move(ueventd_configuration.subsystems), fs_mgr_get_boot_devices(), true));
-        uevent_handlers.emplace_back(std::make_unique<FirmwareHandler>(
-                std::move(ueventd_configuration.firmware_directories)));
+    uevent_handlers.emplace_back(std::make_unique<DeviceHandler>(
+            std::move(ueventd_configuration.dev_permissions),
+            std::move(ueventd_configuration.sysfs_permissions),
+            std::move(ueventd_configuration.subsystems), fs_mgr_get_boot_devices(), true));
+    uevent_handlers.emplace_back(std::make_unique<FirmwareHandler>(
+            std::move(ueventd_configuration.firmware_directories)));
 
-        if (ueventd_configuration.enable_modalias_handling) {
-            uevent_handlers.emplace_back(std::make_unique<ModaliasHandler>());
-        }
+    if (ueventd_configuration.enable_modalias_handling) {
+        uevent_handlers.emplace_back(std::make_unique<ModaliasHandler>());
     }
+    UeventListener uevent_listener(ueventd_configuration.uevent_socket_rcvbuf_size);
 
     if (access(COLDBOOT_DONE, F_OK) != 0) {
         ColdBoot cold_boot(uevent_listener, uevent_handlers);
diff --git a/init/ueventd_parser.cpp b/init/ueventd_parser.cpp
index 677938e..aac3fe5 100644
--- a/init/ueventd_parser.cpp
+++ b/init/ueventd_parser.cpp
@@ -19,9 +19,13 @@
 #include <grp.h>
 #include <pwd.h>
 
+#include <android-base/parseint.h>
+
 #include "keyword_map.h"
 #include "parser.h"
 
+using android::base::ParseByteCount;
+
 namespace android {
 namespace init {
 
@@ -101,6 +105,22 @@
     return Success();
 }
 
+Result<Success> ParseUeventSocketRcvbufSizeLine(std::vector<std::string>&& args,
+                                                size_t* uevent_socket_rcvbuf_size) {
+    if (args.size() != 2) {
+        return Error() << "uevent_socket_rcvbuf_size lines take exactly one parameter";
+    }
+
+    size_t parsed_size;
+    if (!ParseByteCount(args[1], &parsed_size)) {
+        return Error() << "could not parse size '" << args[1] << "' for uevent_socket_rcvbuf_line";
+    }
+
+    *uevent_socket_rcvbuf_size = parsed_size;
+
+    return Success();
+}
+
 class SubsystemParser : public SectionParser {
   public:
     SubsystemParser(std::vector<Subsystem>* subsystems) : subsystems_(subsystems) {}
@@ -202,6 +222,9 @@
     parser.AddSingleLineParser("modalias_handling",
                                std::bind(ParseModaliasHandlingLine, _1,
                                          &ueventd_configuration.enable_modalias_handling));
+    parser.AddSingleLineParser("uevent_socket_rcvbuf_size",
+                               std::bind(ParseUeventSocketRcvbufSizeLine, _1,
+                                         &ueventd_configuration.uevent_socket_rcvbuf_size));
 
     for (const auto& config : configs) {
         parser.ParseConfig(config);
diff --git a/init/ueventd_parser.h b/init/ueventd_parser.h
index 7d30edf..d476dec 100644
--- a/init/ueventd_parser.h
+++ b/init/ueventd_parser.h
@@ -31,6 +31,7 @@
     std::vector<Permissions> dev_permissions;
     std::vector<std::string> firmware_directories;
     bool enable_modalias_handling = false;
+    size_t uevent_socket_rcvbuf_size = 0;
 };
 
 UeventdConfiguration ParseConfig(const std::vector<std::string>& configs);
diff --git a/init/ueventd_parser_test.cpp b/init/ueventd_parser_test.cpp
index c3af341..9c1cedf 100644
--- a/init/ueventd_parser_test.cpp
+++ b/init/ueventd_parser_test.cpp
@@ -138,6 +138,15 @@
     TestUeventdFile(ueventd_file, {{}, {}, {}, firmware_directories});
 }
 
+TEST(ueventd_parser, UeventSocketRcvbufSize) {
+    auto ueventd_file = R"(
+uevent_socket_rcvbuf_size 8k
+uevent_socket_rcvbuf_size 8M
+)";
+
+    TestUeventdFile(ueventd_file, {{}, {}, {}, {}, false, 8 * 1024 * 1024});
+}
+
 TEST(ueventd_parser, AllTogether) {
     auto ueventd_file = R"(
 
@@ -169,6 +178,8 @@
 /sys/devices/virtual/*/input   poll_delay  0660  root   input
 firmware_directories /more
 
+uevent_socket_rcvbuf_size 6M
+
 #ending comment
 )";
 
@@ -197,8 +208,10 @@
             "/more",
     };
 
-    TestUeventdFile(ueventd_file,
-                    {subsystems, sysfs_permissions, permissions, firmware_directories});
+    size_t uevent_socket_rcvbuf_size = 6 * 1024 * 1024;
+
+    TestUeventdFile(ueventd_file, {subsystems, sysfs_permissions, permissions, firmware_directories,
+                                   false, uevent_socket_rcvbuf_size});
 }
 
 // All of these lines are ill-formed, so test that there is 0 output.
@@ -213,6 +226,8 @@
 /sys/devices/platform/trusty.*      trusty_version        0440  baduidbad   log
 /sys/devices/platform/trusty.*      trusty_version        0440  root   baduidbad
 
+uevent_socket_rcvbuf_size blah
+
 subsystem #no name
 
 )";
diff --git a/libcutils/fs_config.cpp b/libcutils/fs_config.cpp
index ee52f5e..db59569 100644
--- a/libcutils/fs_config.cpp
+++ b/libcutils/fs_config.cpp
@@ -108,7 +108,9 @@
 // although the developer is advised to restrict the scope to the /vendor or
 // oem/ file-system since the intent is to provide support for customized
 // portions of a separate vendor.img or oem.img.  Has to remain open so that
-// customization can also land on /system/vendor, /system/oem or /system/odm.
+// customization can also land on /system/vendor, /system/oem, /system/odm,
+// /system/product or /system/product_services.
+//
 // We expect build-time checking or filtering when constructing the associated
 // fs_config_* files (see build/tools/fs_config/fs_config_generate.c)
 static const char ven_conf_dir[] = "/vendor/etc/fs_config_dirs";
@@ -117,11 +119,17 @@
 static const char oem_conf_file[] = "/oem/etc/fs_config_files";
 static const char odm_conf_dir[] = "/odm/etc/fs_config_dirs";
 static const char odm_conf_file[] = "/odm/etc/fs_config_files";
+static const char product_conf_dir[] = "/product/etc/fs_config_dirs";
+static const char product_conf_file[] = "/product/etc/fs_config_files";
+static const char product_services_conf_dir[] = "/product_services/etc/fs_config_dirs";
+static const char product_services_conf_file[] = "/product_services/etc/fs_config_files";
 static const char* conf[][2] = {
-    {sys_conf_file, sys_conf_dir},
-    {ven_conf_file, ven_conf_dir},
-    {oem_conf_file, oem_conf_dir},
-    {odm_conf_file, odm_conf_dir},
+        {sys_conf_file, sys_conf_dir},
+        {ven_conf_file, ven_conf_dir},
+        {oem_conf_file, oem_conf_dir},
+        {odm_conf_file, odm_conf_dir},
+        {product_conf_file, product_conf_dir},
+        {product_services_conf_file, product_services_conf_dir},
 };
 
 // Do not use android_files to grant Linux capabilities.  Use ambient capabilities in their
@@ -150,7 +158,11 @@
     { 00444, AID_ROOT,      AID_ROOT,      0, oem_conf_dir + 1 },
     { 00444, AID_ROOT,      AID_ROOT,      0, oem_conf_file + 1 },
     { 00600, AID_ROOT,      AID_ROOT,      0, "product/build.prop" },
+    { 00444, AID_ROOT,      AID_ROOT,      0, product_conf_dir + 1 },
+    { 00444, AID_ROOT,      AID_ROOT,      0, product_conf_file + 1 },
     { 00600, AID_ROOT,      AID_ROOT,      0, "product_services/build.prop" },
+    { 00444, AID_ROOT,      AID_ROOT,      0, product_services_conf_dir + 1 },
+    { 00444, AID_ROOT,      AID_ROOT,      0, product_services_conf_file + 1 },
     { 00750, AID_ROOT,      AID_SHELL,     0, "sbin/fs_mgr" },
     { 00755, AID_ROOT,      AID_SHELL,     0, "system/bin/crash_dump32" },
     { 00755, AID_ROOT,      AID_SHELL,     0, "system/bin/crash_dump64" },
@@ -236,10 +248,10 @@
     return fd;
 }
 
-// if path is "odm/<stuff>", "oem/<stuff>", "product/<stuff>" or
-// "vendor/<stuff>"
+// if path is "odm/<stuff>", "oem/<stuff>", "product/<stuff>",
+// "product_services/<stuff>" or "vendor/<stuff>"
 static bool is_partition(const char* path, size_t len) {
-    static const char* partitions[] = {"odm/", "oem/", "product/", "vendor/"};
+    static const char* partitions[] = {"odm/", "oem/", "product/", "product_services/", "vendor/"};
     for (size_t i = 0; i < (sizeof(partitions) / sizeof(partitions[0])); ++i) {
         size_t plen = strlen(partitions[i]);
         if (len <= plen) continue;
diff --git a/libcutils/uevent.cpp b/libcutils/uevent.cpp
index 2dfceed..721de7c 100644
--- a/libcutils/uevent.cpp
+++ b/libcutils/uevent.cpp
@@ -95,6 +95,8 @@
 int uevent_open_socket(int buf_sz, bool passcred) {
     struct sockaddr_nl addr;
     int on = passcred;
+    int buf_sz_readback = 0;
+    socklen_t optlen = sizeof(buf_sz_readback);
     int s;
 
     memset(&addr, 0, sizeof(addr));
@@ -105,11 +107,21 @@
     s = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT);
     if (s < 0) return -1;
 
-    /* buf_sz should be less than net.core.rmem_max for this to succeed */
-    if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &buf_sz, sizeof(buf_sz)) < 0) {
+    if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &buf_sz, sizeof(buf_sz)) < 0 ||
+          getsockopt(s, SOL_SOCKET, SO_RCVBUF, &buf_sz_readback, &optlen) < 0) {
         close(s);
         return -1;
     }
+    /* Only if SO_RCVBUF was not effective, try SO_RCVBUFFORCE. Generally, we
+     * want to avoid SO_RCVBUFFORCE, because it generates SELinux denials in
+     * case we don't have CAP_NET_ADMIN. This is the case, for example, for
+     * healthd. */
+    if (buf_sz_readback < 2 * buf_sz) {
+        if (setsockopt(s, SOL_SOCKET, SO_RCVBUFFORCE, &buf_sz, sizeof(buf_sz)) < 0) {
+            close(s);
+            return -1;
+        }
+    }
 
     setsockopt(s, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
 
diff --git a/libmeminfo/Android.bp b/libmeminfo/Android.bp
index aab3743..3e191ad 100644
--- a/libmeminfo/Android.bp
+++ b/libmeminfo/Android.bp
@@ -54,6 +54,11 @@
     srcs: [
         "libmeminfo_test.cpp"
     ],
+
+    data: [
+        "testdata1/*",
+        "testdata2/*"
+    ],
 }
 
 cc_benchmark {
@@ -67,4 +72,8 @@
         "libmeminfo",
         "libprocinfo",
     ],
+
+    data: [
+        "testdata1/*",
+    ],
 }
diff --git a/libmeminfo/OWNERS b/libmeminfo/OWNERS
new file mode 100644
index 0000000..26e71fe
--- /dev/null
+++ b/libmeminfo/OWNERS
@@ -0,0 +1 @@
+sspatil@google.com
diff --git a/libmeminfo/include/meminfo/meminfo.h b/libmeminfo/include/meminfo/meminfo.h
index c328648..809054b 100644
--- a/libmeminfo/include/meminfo/meminfo.h
+++ b/libmeminfo/include/meminfo/meminfo.h
@@ -31,6 +31,8 @@
     uint64_t pss;
     uint64_t uss;
 
+    uint64_t swap;
+
     uint64_t private_clean;
     uint64_t private_dirty;
     uint64_t shared_clean;
@@ -41,6 +43,7 @@
           rss(0),
           pss(0),
           uss(0),
+          swap(0),
           private_clean(0),
           private_dirty(0),
           shared_clean(0),
@@ -49,7 +52,7 @@
     ~MemUsage() = default;
 
     void clear() {
-        vss = rss = pss = uss = 0;
+        vss = rss = pss = uss = swap = 0;
         private_clean = private_dirty = shared_clean = shared_dirty = 0;
     }
 };
diff --git a/libmeminfo/include/meminfo/procmeminfo.h b/libmeminfo/include/meminfo/procmeminfo.h
index b37c56b..92375d3 100644
--- a/libmeminfo/include/meminfo/procmeminfo.h
+++ b/libmeminfo/include/meminfo/procmeminfo.h
@@ -29,13 +29,16 @@
 class ProcMemInfo final {
     // Per-process memory accounting
   public:
-    ProcMemInfo(pid_t pid, bool get_wss = false);
+    // Reset the working set accounting of the process via /proc/<pid>/clear_refs
+    static bool ResetWorkingSet(pid_t pid);
+
+    ProcMemInfo(pid_t pid, bool get_wss = false, uint64_t pgflags = 0, uint64_t pgflags_mask = 0);
 
     const std::vector<Vma>& Maps();
     const MemUsage& Usage();
     const MemUsage& Wss();
+    const std::vector<uint16_t>& SwapOffsets();
 
-    bool WssReset();
     ~ProcMemInfo() = default;
 
   private:
@@ -44,11 +47,14 @@
 
     pid_t pid_;
     bool get_wss_;
+    uint64_t pgflags_;
+    uint64_t pgflags_mask_;
 
     std::vector<Vma> maps_;
 
     MemUsage usage_;
     MemUsage wss_;
+    std::vector<uint16_t> swap_offsets_;
 };
 
 }  // namespace meminfo
diff --git a/libmeminfo/include/meminfo/sysmeminfo.h b/libmeminfo/include/meminfo/sysmeminfo.h
index f5e05bd..885be1d 100644
--- a/libmeminfo/include/meminfo/sysmeminfo.h
+++ b/libmeminfo/include/meminfo/sysmeminfo.h
@@ -28,6 +28,21 @@
 class SysMemInfo final {
     // System or Global memory accounting
   public:
+    static constexpr const char* kMemTotal = "MemTotal:";
+    static constexpr const char* kMemFree = "MemFree:";
+    static constexpr const char* kMemBuffers = "Buffers:";
+    static constexpr const char* kMemCached = "Cached:";
+    static constexpr const char* kMemShmem = "Shmem:";
+    static constexpr const char* kMemSlab = "Slab:";
+    static constexpr const char* kMemSReclaim = "SReclaimable:";
+    static constexpr const char* kMemSUnreclaim = "SUnreclaim:";
+    static constexpr const char* kMemSwapTotal = "SwapTotal:";
+    static constexpr const char* kMemSwapFree = "SwapFree:";
+    static constexpr const char* kMemMapped = "Mapped:";
+    static constexpr const char* kMemVmallocUsed = "VmallocUsed:";
+    static constexpr const char* kMemPageTables = "PageTables:";
+    static constexpr const char* kMemKernelStack = "KernelStack:";
+
     static const std::vector<std::string> kDefaultSysMemInfoTags;
 
     SysMemInfo() = default;
@@ -38,24 +53,25 @@
                      const std::string& path = "/proc/meminfo");
 
     // getters
-    uint64_t mem_total_kb() { return mem_in_kb_["MemTotal:"]; }
-    uint64_t mem_free_kb() { return mem_in_kb_["MemFree:"]; }
-    uint64_t mem_buffers_kb() { return mem_in_kb_["Buffers:"]; }
-    uint64_t mem_cached_kb() { return mem_in_kb_["Cached:"]; }
-    uint64_t mem_shmem_kb() { return mem_in_kb_["Shmem:"]; }
-    uint64_t mem_slab_kb() { return mem_in_kb_["Slab:"]; }
-    uint64_t mem_slab_reclailmable_kb() { return mem_in_kb_["SReclaimable:"]; }
-    uint64_t mem_slab_unreclaimable_kb() { return mem_in_kb_["SUnreclaim:"]; }
-    uint64_t mem_swap_kb() { return mem_in_kb_["SwapTotal:"]; }
-    uint64_t mem_free_swap_kb() { return mem_in_kb_["SwapFree:"]; }
-    uint64_t mem_zram_kb() { return mem_in_kb_["Zram:"]; }
-    uint64_t mem_mapped_kb() { return mem_in_kb_["Mapped:"]; }
-    uint64_t mem_vmalloc_used_kb() { return mem_in_kb_["VmallocUsed:"]; }
-    uint64_t mem_page_tables_kb() { return mem_in_kb_["PageTables:"]; }
-    uint64_t mem_kernel_stack_kb() { return mem_in_kb_["KernelStack:"]; }
+    uint64_t mem_total_kb() { return mem_in_kb_[kMemTotal]; }
+    uint64_t mem_free_kb() { return mem_in_kb_[kMemFree]; }
+    uint64_t mem_buffers_kb() { return mem_in_kb_[kMemBuffers]; }
+    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_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_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);
 };
 
 }  // namespace meminfo
diff --git a/libmeminfo/libmeminfo_benchmark.cpp b/libmeminfo/libmeminfo_benchmark.cpp
index e2239f0..1db0824 100644
--- a/libmeminfo/libmeminfo_benchmark.cpp
+++ b/libmeminfo/libmeminfo_benchmark.cpp
@@ -17,6 +17,8 @@
 #include <meminfo/sysmeminfo.h>
 
 #include <fcntl.h>
+#include <inttypes.h>
+#include <stdio.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 
@@ -46,7 +48,7 @@
     MEMINFO_COUNT
 };
 
-void get_mem_info(uint64_t mem[], const char* file) {
+static void get_mem_info(uint64_t mem[], const char* file) {
     char buffer[4096];
     unsigned int numFound = 0;
 
@@ -67,9 +69,10 @@
     buffer[len] = 0;
 
     static const char* const tags[] = {
-            "MemTotal:",     "MemFree:",    "Buffers:",     "Cached:",       "Shmem:", "Slab:",
-            "SReclaimable:", "SUnreclaim:", "SwapTotal:",   "SwapFree:",     "ZRam:",  "Mapped:",
-            "VmallocUsed:",  "PageTables:", "KernelStack:", NULL};
+            "MemTotal:",     "MemFree:",    "Buffers:",     "Cached:",   "Shmem:", "Slab:",
+            "SReclaimable:", "SUnreclaim:", "SwapTotal:",   "SwapFree:", "ZRam:",  "Mapped:",
+            "VmallocUsed:",  "PageTables:", "KernelStack:", NULL
+    };
 
     static const int tagsLen[] = {9, 8, 8, 7, 6, 5, 13, 11, 10, 9, 5, 7, 12, 11, 12, 0};
 
@@ -78,7 +81,8 @@
     while (*p && (numFound < (sizeof(tagsLen) / sizeof(tagsLen[0])))) {
         int i = 0;
         while (tags[i]) {
-            //std::cout << "tag =" << tags[i] << " p = " << std::string(p, tagsLen[i]) << std::endl;
+            // std::cout << "tag =" << tags[i] << " p = " << std::string(p, tagsLen[i]) <<
+            // std::endl;
             if (strncmp(p, tags[i], tagsLen[i]) == 0) {
                 p += tagsLen[i];
                 while (*p == ' ') p++;
@@ -214,4 +218,51 @@
 }
 BENCHMARK(BM_ReadMemInfo);
 
+static uint64_t get_zram_mem_used(const std::string& zram_dir) {
+    FILE* f = fopen((zram_dir + "mm_stat").c_str(), "r");
+    if (f) {
+        uint64_t mem_used_total = 0;
+
+        int matched = fscanf(f, "%*d %*d %" SCNu64 " %*d %*d %*d %*d", &mem_used_total);
+        if (matched != 1)
+            fprintf(stderr, "warning: failed to parse %s\n", (zram_dir + "mm_stat").c_str());
+
+        fclose(f);
+        return mem_used_total;
+    }
+
+    f = fopen((zram_dir + "mem_used_total").c_str(), "r");
+    if (f) {
+        uint64_t mem_used_total = 0;
+
+        int matched = fscanf(f, "%" SCNu64, &mem_used_total);
+        if (matched != 1)
+            fprintf(stderr, "warning: failed to parse %s\n", (zram_dir + "mem_used_total").c_str());
+
+        fclose(f);
+        return mem_used_total;
+    }
+
+    return 0;
+}
+
+static void BM_OldReadZramTotal(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);
+
+static void BM_NewReadZramTotal(benchmark::State& state) {
+    std::string exec_dir = ::android::base::GetExecutableDirectory();
+    std::string zram_mmstat_dir = exec_dir + "/testdata1/";
+    ::android::meminfo::SysMemInfo mi;
+    for (auto _ : state) {
+        uint64_t zram_total __attribute__((unused)) = mi.mem_zram_kb(zram_mmstat_dir);
+    }
+}
+BENCHMARK(BM_NewReadZramTotal);
+
 BENCHMARK_MAIN();
diff --git a/libmeminfo/libmeminfo_test.cpp b/libmeminfo/libmeminfo_test.cpp
index 7a2be41..b7a4b6b 100644
--- a/libmeminfo/libmeminfo_test.cpp
+++ b/libmeminfo/libmeminfo_test.cpp
@@ -73,7 +73,7 @@
     }
 }
 
-TEST_F(ValidateProcMemInfo, TestMapsUsage) {
+TEST_F(ValidateProcMemInfo, TestMaps) {
     const std::vector<Vma>& maps = proc_mem->Maps();
     ASSERT_FALSE(maps.empty());
     ASSERT_EQ(proc->num_maps, maps.size());
@@ -96,6 +96,30 @@
     EXPECT_EQ(proc_usage.uss, proc_mem->Usage().uss);
 }
 
+TEST_F(ValidateProcMemInfo, TestSwapUsage) {
+    const std::vector<Vma>& maps = proc_mem->Maps();
+    ASSERT_FALSE(maps.empty());
+    ASSERT_EQ(proc->num_maps, maps.size());
+
+    pm_memusage_t map_usage, proc_usage;
+    pm_memusage_zero(&map_usage);
+    pm_memusage_zero(&proc_usage);
+    for (size_t i = 0; i < maps.size(); i++) {
+        ASSERT_EQ(0, pm_map_usage(proc->maps[i], &map_usage));
+        EXPECT_EQ(map_usage.swap, maps[i].usage.swap) << "SWAP mismatch for map: " << maps[i].name;
+        pm_memusage_add(&proc_usage, &map_usage);
+    }
+
+    EXPECT_EQ(proc_usage.swap, proc_mem->Usage().swap);
+}
+
+TEST_F(ValidateProcMemInfo, TestSwapOffsets) {
+    const MemUsage& proc_usage = proc_mem->Usage();
+    const std::vector<uint16_t>& swap_offsets = proc_mem->SwapOffsets();
+
+    EXPECT_EQ(proc_usage.swap / getpagesize(), swap_offsets.size());
+}
+
 class ValidateProcMemInfoWss : public ::testing::Test {
   protected:
     void SetUp() override {
@@ -118,7 +142,7 @@
 
 TEST_F(ValidateProcMemInfoWss, TestWorkingTestReset) {
     // Expect reset to succeed
-    EXPECT_TRUE(proc_mem->WssReset());
+    EXPECT_TRUE(ProcMemInfo::ResetWorkingSet(pid));
 }
 
 TEST_F(ValidateProcMemInfoWss, TestWssEquality) {
@@ -221,6 +245,93 @@
     }
 }
 
+TEST(TestProcMemInfo, TestMapsEmpty) {
+    ProcMemInfo proc_mem(pid);
+    const std::vector<Vma>& maps = proc_mem.Maps();
+    EXPECT_GT(maps.size(), 0);
+}
+
+TEST(TestProcMemInfo, TestUsageEmpty) {
+    // If we created the object for getting working set,
+    // the usage must be empty
+    ProcMemInfo proc_mem(pid, true);
+    const MemUsage& usage = proc_mem.Usage();
+    EXPECT_EQ(usage.rss, 0);
+    EXPECT_EQ(usage.vss, 0);
+    EXPECT_EQ(usage.pss, 0);
+    EXPECT_EQ(usage.uss, 0);
+    EXPECT_EQ(usage.swap, 0);
+}
+
+TEST(TestProcMemInfoWssReset, TestWssEmpty) {
+    // If we created the object for getting usage,
+    // the working set must be empty
+    ProcMemInfo proc_mem(pid, false);
+    const MemUsage& wss = proc_mem.Wss();
+    EXPECT_EQ(wss.rss, 0);
+    EXPECT_EQ(wss.vss, 0);
+    EXPECT_EQ(wss.pss, 0);
+    EXPECT_EQ(wss.uss, 0);
+    EXPECT_EQ(wss.swap, 0);
+}
+
+TEST(TestProcMemInfoWssReset, TestSwapOffsetsEmpty) {
+    // If we created the object for getting working set,
+    // the swap offsets must be empty
+    ProcMemInfo proc_mem(pid, true);
+    const std::vector<uint16_t>& swap_offsets = proc_mem.SwapOffsets();
+    EXPECT_EQ(swap_offsets.size(), 0);
+}
+
+TEST(ValidateProcMemInfoFlags, TestPageFlags1) {
+    // Create proc object using libpagemap
+    pm_kernel_t* ker;
+    ASSERT_EQ(0, pm_kernel_create(&ker));
+    pm_process_t* proc;
+    ASSERT_EQ(0, pm_process_create(ker, pid, &proc));
+
+    // count swapbacked pages using libpagemap
+    pm_memusage_t proc_usage;
+    pm_memusage_zero(&proc_usage);
+    ASSERT_EQ(0, pm_process_usage_flags(proc, &proc_usage, (1 << KPF_SWAPBACKED),
+                                        (1 << KPF_SWAPBACKED)));
+
+    // Create ProcMemInfo that counts swapbacked pages
+    ProcMemInfo proc_mem(pid, false, (1 << KPF_SWAPBACKED), (1 << KPF_SWAPBACKED));
+
+    EXPECT_EQ(proc_usage.vss, proc_mem.Usage().vss);
+    EXPECT_EQ(proc_usage.rss, proc_mem.Usage().rss);
+    EXPECT_EQ(proc_usage.pss, proc_mem.Usage().pss);
+    EXPECT_EQ(proc_usage.uss, proc_mem.Usage().uss);
+
+    pm_process_destroy(proc);
+    pm_kernel_destroy(ker);
+}
+
+TEST(ValidateProcMemInfoFlags, TestPageFlags2) {
+    // Create proc object using libpagemap
+    pm_kernel_t* ker;
+    ASSERT_EQ(0, pm_kernel_create(&ker));
+    pm_process_t* proc;
+    ASSERT_EQ(0, pm_process_create(ker, pid, &proc));
+
+    // count non-swapbacked pages using libpagemap
+    pm_memusage_t proc_usage;
+    pm_memusage_zero(&proc_usage);
+    ASSERT_EQ(0, pm_process_usage_flags(proc, &proc_usage, (1 << KPF_SWAPBACKED), 0));
+
+    // Create ProcMemInfo that counts non-swapbacked pages
+    ProcMemInfo proc_mem(pid, false, 0, (1 << KPF_SWAPBACKED));
+
+    EXPECT_EQ(proc_usage.vss, proc_mem.Usage().vss);
+    EXPECT_EQ(proc_usage.rss, proc_mem.Usage().rss);
+    EXPECT_EQ(proc_usage.pss, proc_mem.Usage().pss);
+    EXPECT_EQ(proc_usage.uss, proc_mem.Usage().uss);
+
+    pm_process_destroy(proc);
+    pm_kernel_destroy(ker);
+}
+
 TEST(SysMemInfoParser, TestSysMemInfoFile) {
     std::string meminfo = R"meminfo(MemTotal:        3019740 kB
 MemFree:         1809728 kB
@@ -288,6 +399,17 @@
     EXPECT_EQ(mi.mem_total_kb(), 0);
 }
 
+TEST(SysMemInfoParse, TestZramTotal) {
+    std::string exec_dir = ::android::base::GetExecutableDirectory();
+
+    SysMemInfo mi;
+    std::string zram_mmstat_dir = exec_dir + "/testdata1/";
+    EXPECT_EQ(mi.mem_zram_kb(zram_mmstat_dir), 30504);
+
+    std::string zram_memused_dir = exec_dir + "/testdata2/";
+    EXPECT_EQ(mi.mem_zram_kb(zram_memused_dir), 30504);
+}
+
 int main(int argc, char** argv) {
     ::testing::InitGoogleTest(&argc, argv);
     if (argc <= 1) {
diff --git a/libmeminfo/procmeminfo.cpp b/libmeminfo/procmeminfo.cpp
index fe91d25..8867e14 100644
--- a/libmeminfo/procmeminfo.cpp
+++ b/libmeminfo/procmeminfo.cpp
@@ -44,6 +44,8 @@
     to->pss += from.pss;
     to->uss += from.uss;
 
+    to->swap += from.swap;
+
     to->private_clean += from.private_clean;
     to->private_dirty += from.private_dirty;
 
@@ -51,48 +53,78 @@
     to->shared_dirty += from.shared_dirty;
 }
 
-ProcMemInfo::ProcMemInfo(pid_t pid, bool get_wss) : pid_(pid), get_wss_(get_wss) {
-    if (!ReadMaps(get_wss_)) {
-        LOG(ERROR) << "Failed to read maps for Process " << pid_;
-    }
-}
-
-const std::vector<Vma>& ProcMemInfo::Maps() {
-    return maps_;
-}
-
-const MemUsage& ProcMemInfo::Usage() {
-    if (get_wss_) {
-        LOG(WARNING) << "Trying to read memory usage from working set object";
-    }
-    return usage_;
-}
-
-const MemUsage& ProcMemInfo::Wss() {
-    if (!get_wss_) {
-        LOG(WARNING) << "Trying to read working set when there is none";
-    }
-
-    return wss_;
-}
-
-bool ProcMemInfo::WssReset() {
-    if (!get_wss_) {
-        LOG(ERROR) << "Trying to reset working set from a memory usage counting object";
-        return false;
-    }
-
-    std::string clear_refs_path = ::android::base::StringPrintf("/proc/%d/clear_refs", pid_);
+bool ProcMemInfo::ResetWorkingSet(pid_t pid) {
+    std::string clear_refs_path = ::android::base::StringPrintf("/proc/%d/clear_refs", pid);
     if (!::android::base::WriteStringToFile("1\n", clear_refs_path)) {
         PLOG(ERROR) << "Failed to write to " << clear_refs_path;
         return false;
     }
 
-    wss_.clear();
     return true;
 }
 
+ProcMemInfo::ProcMemInfo(pid_t pid, bool get_wss, uint64_t pgflags, uint64_t pgflags_mask)
+    : pid_(pid), get_wss_(get_wss), pgflags_(pgflags), pgflags_mask_(pgflags_mask) {}
+
+const std::vector<Vma>& ProcMemInfo::Maps() {
+    if (maps_.empty() && !ReadMaps(get_wss_)) {
+        LOG(ERROR) << "Failed to read maps for Process " << pid_;
+    }
+
+    return maps_;
+}
+
+const MemUsage& ProcMemInfo::Usage() {
+    if (get_wss_) {
+        LOG(WARNING) << "Trying to read process memory usage for " << pid_
+                     << " using invalid object";
+        return usage_;
+    }
+
+    if (maps_.empty() && !ReadMaps(get_wss_)) {
+        LOG(ERROR) << "Failed to get memory usage for Process " << pid_;
+    }
+
+    return usage_;
+}
+
+const MemUsage& ProcMemInfo::Wss() {
+    if (!get_wss_) {
+        LOG(WARNING) << "Trying to read process working set for " << pid_
+                     << " using invalid object";
+        return wss_;
+    }
+
+    if (maps_.empty() && !ReadMaps(get_wss_)) {
+        LOG(ERROR) << "Failed to get working set for Process " << pid_;
+    }
+
+    return wss_;
+}
+
+const std::vector<uint16_t>& ProcMemInfo::SwapOffsets() {
+    if (get_wss_) {
+        LOG(WARNING) << "Trying to read process swap offsets for " << pid_
+                     << " using invalid object";
+        return swap_offsets_;
+    }
+
+    if (maps_.empty() && !ReadMaps(get_wss_)) {
+        LOG(ERROR) << "Failed to get swap offsets for Process " << pid_;
+    }
+
+    return swap_offsets_;
+}
+
 bool ProcMemInfo::ReadMaps(bool get_wss) {
+    // Each object reads /proc/<pid>/maps only once. This is done to make sure programs that are
+    // running for the lifetime of the system can recycle the objects and don't have to
+    // unnecessarily retain and update this object in memory (which can get significantly large).
+    // E.g. A program that only needs to reset the working set will never all ->Maps(), ->Usage().
+    // E.g. A program that is monitoring smaps_rollup, may never call ->maps(), Usage(), so it
+    // doesn't make sense for us to parse and retain unnecessary memory accounting stats by default.
+    if (!maps_.empty()) return true;
+
     // parse and read /proc/<pid>/maps
     std::string maps_file = ::android::base::StringPrintf("/proc/%d/maps", pid_);
     if (!::android::procinfo::ReadMapFile(
@@ -115,8 +147,8 @@
 
     for (auto& vma : maps_) {
         if (!ReadVmaStats(pagemap_fd.get(), vma, get_wss)) {
-            LOG(ERROR) << "Failed to read page map for vma " << vma.name << "[" << vma.start
-                       << "-" << vma.end << "]";
+            LOG(ERROR) << "Failed to read page map for vma " << vma.name << "[" << vma.start << "-"
+                       << vma.end << "]";
             maps_.clear();
             return false;
         }
@@ -153,18 +185,24 @@
         if (!PAGE_PRESENT(p) && !PAGE_SWAPPED(p)) continue;
 
         if (PAGE_SWAPPED(p)) {
-            // TODO: do what's needed for swapped pages
+            vma.usage.swap += pagesz;
+            swap_offsets_.emplace_back(PAGE_SWAP_OFFSET(p));
             continue;
         }
 
         uint64_t page_frame = PAGE_PFN(p);
         if (!pinfo.PageFlags(page_frame, &pg_flags[i])) {
             LOG(ERROR) << "Failed to get page flags for " << page_frame << " in process " << pid_;
+            swap_offsets_.clear();
             return false;
         }
 
+        // skip unwanted pages from the count
+        if ((pg_flags[i] & pgflags_mask_) != pgflags_) continue;
+
         if (!pinfo.PageMapCount(page_frame, &pg_counts[i])) {
             LOG(ERROR) << "Failed to get page count for " << page_frame << " in process " << pid_;
+            swap_offsets_.clear();
             return false;
         }
 
diff --git a/libmeminfo/sysmeminfo.cpp b/libmeminfo/sysmeminfo.cpp
index 50fa213..7e56238 100644
--- a/libmeminfo/sysmeminfo.cpp
+++ b/libmeminfo/sysmeminfo.cpp
@@ -17,10 +17,12 @@
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 #include <cctype>
+#include <cstdio>
 #include <fstream>
 #include <string>
 #include <utility>
@@ -29,7 +31,9 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
+#include <android-base/stringprintf.h>
 #include <android-base/strings.h>
+#include <android-base/unique_fd.h>
 
 #include "meminfo_private.h"
 
@@ -37,9 +41,11 @@
 namespace meminfo {
 
 const std::vector<std::string> SysMemInfo::kDefaultSysMemInfoTags = {
-    "MemTotal:", "MemFree:",      "Buffers:",     "Cached:",     "Shmem:",
-    "Slab:",     "SReclaimable:", "SUnreclaim:",  "SwapTotal:",  "SwapFree:",
-    "ZRam:",     "Mapped:",       "VmallocUsed:", "PageTables:", "KernelStack:",
+        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,
 };
 
 bool SysMemInfo::ReadMemInfo(const std::string& path) {
@@ -99,6 +105,7 @@
     buffer[len] = '\0';
     char* p = buffer;
     uint32_t found = 0;
+    uint32_t lineno = 0;
     while (*p && found < tags.size()) {
         for (auto& tag : tags) {
             if (strncmp(p, tag.c_str(), tag.size()) == 0) {
@@ -107,7 +114,7 @@
                 char* endptr = nullptr;
                 mem_in_kb_[tag] = strtoull(p, &endptr, 10);
                 if (p == endptr) {
-                    PLOG(ERROR) << "Failed to parse line in file: " << path;
+                    PLOG(ERROR) << "Failed to parse line:" << lineno + 1 << " in file: " << path;
                     return false;
                 }
                 p = endptr;
@@ -119,11 +126,75 @@
             p++;
         }
         if (*p) p++;
+        lineno++;
     }
 
     return true;
 }
 #endif
 
+uint64_t SysMemInfo::mem_zram_kb(const std::string& zram_dev) {
+    uint64_t mem_zram_total = 0;
+    if (!zram_dev.empty()) {
+        if (!MemZramDevice(zram_dev, &mem_zram_total)) {
+            return 0;
+        }
+        return mem_zram_total / 1024;
+    }
+
+    constexpr uint32_t kMaxZramDevices = 256;
+    for (uint32_t i = 0; i < kMaxZramDevices; i++) {
+        std::string zram_dev = ::android::base::StringPrintf("/sys/block/zram%u/", i);
+        if (access(zram_dev.c_str(), F_OK)) {
+            // We assume zram devices appear in range 0-255 and appear always in sequence
+            // under /sys/block. So, stop looking for them once we find one is missing.
+            break;
+        }
+
+        uint64_t mem_zram_dev;
+        if (!MemZramDevice(zram_dev, &mem_zram_dev)) {
+            return 0;
+        }
+
+        mem_zram_total += mem_zram_dev;
+    }
+
+    return mem_zram_total / 1024;
+}
+
+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;
+            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;
+    }
+
+    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) {
+            PLOG(ERROR) << "Malformed mem_used_total file for zram dev: " << zram_dev
+                        << " content: " << content;
+            return false;
+        }
+
+        return true;
+    }
+
+    LOG(ERROR) << "Can't find memory status under: " << zram_dev;
+    return false;
+}
+
 }  // namespace meminfo
 }  // namespace android
diff --git a/libmeminfo/testdata1/mm_stat b/libmeminfo/testdata1/mm_stat
new file mode 100644
index 0000000..684f567
--- /dev/null
+++ b/libmeminfo/testdata1/mm_stat
@@ -0,0 +1 @@
+145674240 26801454 31236096        0 45772800     3042     1887      517
diff --git a/libmeminfo/testdata2/mem_used_total b/libmeminfo/testdata2/mem_used_total
new file mode 100644
index 0000000..97fcf41
--- /dev/null
+++ b/libmeminfo/testdata2/mem_used_total
@@ -0,0 +1 @@
+31236096
diff --git a/libmeminfo/tools/Android.bp b/libmeminfo/tools/Android.bp
index 0870130..715d63d 100644
--- a/libmeminfo/tools/Android.bp
+++ b/libmeminfo/tools/Android.bp
@@ -22,6 +22,22 @@
 
     srcs: ["procmem.cpp"],
     shared_libs: [
+        "libbase",
+        "libmeminfo",
+    ],
+}
+
+cc_binary {
+    name: "procrank2",
+    cflags: [
+        "-Wall",
+        "-Werror",
+        "-Wno-unused-parameter",
+    ],
+
+    srcs: ["procrank.cpp"],
+    shared_libs: [
+        "libbase",
         "libmeminfo",
     ],
 }
diff --git a/libmeminfo/tools/procmem.cpp b/libmeminfo/tools/procmem.cpp
index 3571e41..56de12d 100644
--- a/libmeminfo/tools/procmem.cpp
+++ b/libmeminfo/tools/procmem.cpp
@@ -15,20 +15,33 @@
  */
 
 #include <errno.h>
+#include <inttypes.h>
 #include <stdlib.h>
 #include <unistd.h>
 
-#include <iomanip>
 #include <iostream>
 #include <sstream>
 #include <string>
 #include <vector>
 
+#include <android-base/stringprintf.h>
 #include <meminfo/procmeminfo.h>
 
+using Vma = ::android::meminfo::Vma;
 using ProcMemInfo = ::android::meminfo::ProcMemInfo;
 using MemUsage = ::android::meminfo::MemUsage;
 
+// Global flags to control procmem output
+
+// Set to use page idle bits for working set detection
+bool use_pageidle = false;
+// hides map entries with zero rss
+bool hide_zeroes = false;
+// Reset working set and exit
+bool reset_wss = false;
+// Show working set, mutually exclusive with reset_wss;
+bool show_wss = false;
+
 static void usage(const char* cmd) {
     fprintf(stderr,
             "Usage: %s [-i] [ -w | -W ] [ -p | -m ] [ -h ] pid\n"
@@ -42,68 +55,56 @@
             cmd);
 }
 
-static void show_footer(uint32_t nelem, const std::string& padding) {
-    std::string elem(7, '-');
-
-    for (uint32_t i = 0; i < nelem; ++i) {
-        std::cout << std::setw(7) << elem << padding;
+static void print_separator(std::stringstream& ss) {
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %7s  %7s  %7s  %7s  %7s  %7s  %s\n", "-------",
+                                            "-------", "-------", "-------", "-------", "-------",
+                                            "-------", "");
+        return;
     }
-    std::cout << std::endl;
+    ss << ::android::base::StringPrintf("%7s  %7s  %7s  %7s  %7s  %7s  %7s  %7s  %s\n", "-------",
+                                        "-------", "-------", "-------", "-------", "-------",
+                                        "-------", "-------", "");
 }
 
-static void show_header(const std::vector<std::string>& header, const std::string& padding) {
-    if (header.empty()) return;
-
-    for (size_t i = 0; i < header.size() - 1; ++i) {
-        std::cout << std::setw(7) << header[i] << padding;
+static void print_header(std::stringstream& ss) {
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %7s  %7s  %7s  %7s  %7s  %7s  %s\n", "WRss",
+                                            "WPss", "WUss", "WShCl", "WShDi", "WPrCl", "WPrDi",
+                                            "Name");
+    } else {
+        ss << ::android::base::StringPrintf("%7s  %7s  %7s  %7s  %7s  %7s  %7s  %7s  %s\n", "Vss",
+                                            "Rss", "Pss", "Uss", "ShCl", "ShDi", "PrCl", "PrDi",
+                                            "Name");
     }
-    std::cout << header.back() << std::endl;
-    show_footer(header.size() - 1, padding);
+    print_separator(ss);
 }
 
-static void scan_usage(std::stringstream& ss, const MemUsage& usage, const std::string& padding,
-                       bool show_wss) {
-    // clear string stream first.
-    ss.str("");
-    // TODO: use ::android::base::StringPrintf instead of <iomanip> here.
-    if (!show_wss)
-        ss << std::setw(6) << usage.vss/1024 << padding;
-    ss << std::setw(6) << usage.rss/1024 << padding << std::setw(6)
-       << usage.pss/1024 << padding << std::setw(6) << usage.uss/1024 << padding
-       << std::setw(6) << usage.shared_clean/1024 << padding << std::setw(6)
-       << usage.shared_dirty/1024 << padding << std::setw(6)
-       << usage.private_clean/1024 << padding << std::setw(6)
-       << usage.private_dirty/1024 << padding;
+static void print_stats(std::stringstream& ss, const MemUsage& stats) {
+    if (!show_wss) {
+        ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", stats.vss / 1024);
+    }
+
+    ss << ::android::base::StringPrintf("%6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64
+                                        "K  %6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  ",
+                                        stats.rss / 1024, stats.pss / 1024, stats.uss / 1024,
+                                        stats.shared_clean / 1024, stats.shared_dirty / 1024,
+                                        stats.private_clean / 1024, stats.private_dirty / 1024);
 }
 
-static int show(ProcMemInfo& proc, bool hide_zeroes, bool show_wss) {
-    const std::vector<std::string> main_header = {"Vss",  "Rss",  "Pss",  "Uss", "ShCl",
-                                                  "ShDi", "PrCl", "PrDi", "Name"};
-    const std::vector<std::string> wss_header = {"WRss",  "WPss",  "WUss",  "WShCl",
-                                                 "WShDi", "WPrCl", "WPrDi", "Name"};
-    const std::vector<std::string>& header = show_wss ? wss_header : main_header;
-
-    // Read process memory stats
-    const MemUsage& stats = show_wss ? proc.Wss() : proc.Usage();
-    const std::vector<::android::meminfo::Vma>& maps = proc.Maps();
-
-    // following retains 'procmem' output so as to not break any scripts
-    // that rely on it.
-    std::string spaces = "  ";
-    show_header(header, spaces);
-    const std::string padding = "K  ";
+static int show(const MemUsage& proc_stats, const std::vector<Vma>& maps) {
     std::stringstream ss;
+    print_header(ss);
     for (auto& vma : maps) {
         const MemUsage& vma_stats = show_wss ? vma.wss : vma.usage;
         if (hide_zeroes && vma_stats.rss == 0) {
             continue;
         }
-        scan_usage(ss, vma_stats, padding, show_wss);
+        print_stats(ss, vma_stats);
         ss << vma.name << std::endl;
-        std::cout << ss.str();
     }
-    show_footer(header.size() - 1, spaces);
-    scan_usage(ss, stats, padding, show_wss);
+    print_separator(ss);
+    print_stats(ss, proc_stats);
     ss << "TOTAL" << std::endl;
     std::cout << ss.str();
 
@@ -111,28 +112,43 @@
 }
 
 int main(int argc, char* argv[]) {
-    bool use_pageidle = false;
-    bool hide_zeroes = false;
-    bool wss_reset = false;
-    bool show_wss = false;
     int opt;
+    auto pss_sort = [](const Vma& a, const Vma& b) {
+        uint64_t pss_a = show_wss ? a.wss.pss : a.usage.pss;
+        uint64_t pss_b = show_wss ? b.wss.pss : b.usage.pss;
+        return pss_a > pss_b;
+    };
 
+    auto uss_sort = [](const Vma& a, const Vma& b) {
+        uint64_t uss_a = show_wss ? a.wss.uss : a.usage.uss;
+        uint64_t uss_b = show_wss ? b.wss.uss : b.usage.uss;
+        return uss_a > uss_b;
+    };
+
+    std::function<bool(const Vma& a, const Vma& b)> sort_func = nullptr;
     while ((opt = getopt(argc, argv, "himpuWw")) != -1) {
         switch (opt) {
             case 'h':
                 hide_zeroes = true;
                 break;
             case 'i':
+                // TODO: libmeminfo doesn't support the flag to chose
+                // between idle page tracking vs clear_refs. So for now,
+                // this flag is unused and the library defaults to using
+                // /proc/<pid>/clear_refs for finding the working set.
                 use_pageidle = true;
                 break;
             case 'm':
+                // this is the default
                 break;
             case 'p':
+                sort_func = pss_sort;
                 break;
             case 'u':
+                sort_func = uss_sort;
                 break;
             case 'W':
-                wss_reset = true;
+                reset_wss = true;
                 break;
             case 'w':
                 show_wss = true;
@@ -157,15 +173,20 @@
         exit(EXIT_FAILURE);
     }
 
-    bool need_wss = wss_reset || show_wss;
-    ProcMemInfo proc(pid, need_wss);
-    if (wss_reset) {
-        if (!proc.WssReset()) {
+    if (reset_wss) {
+        if (!ProcMemInfo::ResetWorkingSet(pid)) {
             std::cerr << "Failed to reset working set of pid : " << pid << std::endl;
             exit(EXIT_FAILURE);
         }
         return 0;
     }
 
-    return show(proc, hide_zeroes, show_wss);
+    ProcMemInfo proc(pid, show_wss);
+    const MemUsage& proc_stats = show_wss ? proc.Wss() : proc.Usage();
+    std::vector<Vma> maps(proc.Maps());
+    if (sort_func != nullptr) {
+        std::sort(maps.begin(), maps.end(), sort_func);
+    }
+
+    return show(proc_stats, maps);
 }
diff --git a/libmeminfo/tools/procrank.cpp b/libmeminfo/tools/procrank.cpp
new file mode 100644
index 0000000..e39e7fa
--- /dev/null
+++ b/libmeminfo/tools/procrank.cpp
@@ -0,0 +1,530 @@
+/*
+ * 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 <dirent.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/kernel-page-flags.h>
+#include <linux/oom.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <iostream>
+#include <memory>
+#include <sstream>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/parseint.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+
+#include <meminfo/procmeminfo.h>
+#include <meminfo/sysmeminfo.h>
+
+using ::android::meminfo::MemUsage;
+using ::android::meminfo::ProcMemInfo;
+
+struct ProcessRecord {
+  public:
+    ProcessRecord(pid_t pid, bool get_wss = false, uint64_t pgflags = 0, uint64_t pgflags_mask = 0)
+        : pid_(-1),
+          procmem_(nullptr),
+          oomadj_(OOM_SCORE_ADJ_MAX + 1),
+          cmdline_(""),
+          proportional_swap_(0),
+          unique_swap_(0),
+          zswap_(0) {
+        std::unique_ptr<ProcMemInfo> procmem =
+                std::make_unique<ProcMemInfo>(pid, get_wss, pgflags, pgflags_mask);
+        if (procmem == nullptr) {
+            std::cerr << "Failed to create ProcMemInfo for: " << pid << std::endl;
+            return;
+        }
+
+        std::string fname = ::android::base::StringPrintf("/proc/%d/oom_score_adj", pid);
+        auto oomscore_fp =
+                std::unique_ptr<FILE, decltype(&fclose)>{fopen(fname.c_str(), "re"), fclose};
+        if (oomscore_fp == nullptr) {
+            std::cerr << "Failed to open oom_score_adj file: " << fname << std::endl;
+            return;
+        }
+
+        if (fscanf(oomscore_fp.get(), "%d\n", &oomadj_) != 1) {
+            std::cerr << "Failed to read oomadj from: " << fname << std::endl;
+            return;
+        }
+
+        fname = ::android::base::StringPrintf("/proc/%d/cmdline", pid);
+        if (!::android::base::ReadFileToString(fname, &cmdline_)) {
+            std::cerr << "Failed to read cmdline from: " << fname << std::endl;
+            cmdline_ = "<unknown>";
+        }
+        // We deliberately don't read the proc/<pid>cmdline file directly into 'cmdline_'
+        // because of some processes showing up cmdlines that end with "0x00 0x0A 0x00"
+        // e.g. xtra-daemon, lowi-server
+        // The .c_str() assignment below then takes care of trimming the cmdline at the first
+        // 0x00. This is how original procrank worked (luckily)
+        cmdline_.resize(strlen(cmdline_.c_str()));
+        procmem_ = std::move(procmem);
+        pid_ = pid;
+    }
+
+    bool valid() const { return pid_ != -1; }
+
+    void CalculateSwap(const uint16_t* swap_offset_array, float zram_compression_ratio) {
+        const std::vector<uint16_t>& swp_offs = procmem_->SwapOffsets();
+        for (auto& off : swp_offs) {
+            proportional_swap_ += getpagesize() / swap_offset_array[off];
+            unique_swap_ += swap_offset_array[off] == 1 ? getpagesize() : 0;
+            zswap_ = proportional_swap_ * zram_compression_ratio;
+        }
+    }
+
+    // Getters
+    pid_t pid() const { return pid_; }
+    const std::string& cmdline() const { return cmdline_; }
+    int32_t oomadj() const { return oomadj_; }
+    uint64_t proportional_swap() const { return proportional_swap_; }
+    uint64_t unique_swap() const { return unique_swap_; }
+    uint64_t zswap() const { return zswap_; }
+
+    // Wrappers to ProcMemInfo
+    const std::vector<uint16_t>& SwapOffsets() const { return procmem_->SwapOffsets(); }
+    const MemUsage& Usage() const { return procmem_->Usage(); }
+    const MemUsage& Wss() const { return procmem_->Wss(); }
+
+  private:
+    pid_t pid_;
+    std::unique_ptr<ProcMemInfo> procmem_;
+    int32_t oomadj_;
+    std::string cmdline_;
+    uint64_t proportional_swap_;
+    uint64_t unique_swap_;
+    uint64_t zswap_;
+};
+
+// Show working set instead of memory consumption
+bool show_wss = false;
+// Reset working set of each process
+bool reset_wss = false;
+// Show per-process oom_score_adj column
+bool show_oomadj = false;
+// True if the device has swap enabled
+bool has_swap = false;
+// True, if device has zram enabled
+bool has_zram = false;
+// If zram is enabled, the compression ratio is zram used / swap used.
+float zram_compression_ratio = 0.0;
+// Sort process in reverse, default is descending
+bool reverse_sort = false;
+
+// Calculated total memory usage across all processes in the system
+uint64_t total_pss = 0;
+uint64_t total_uss = 0;
+uint64_t total_swap = 0;
+uint64_t total_pswap = 0;
+uint64_t total_uswap = 0;
+uint64_t total_zswap = 0;
+
+static void usage(const char* myname) {
+    std::cerr << "Usage: " << myname << " [ -W ] [ -v | -r | -p | -u | -s | -h ]" << std::endl
+              << "    -v  Sort by VSS." << std::endl
+              << "    -r  Sort by RSS." << std::endl
+              << "    -p  Sort by PSS." << std::endl
+              << "    -u  Sort by USS." << std::endl
+              << "    -s  Sort by swap." << std::endl
+              << "        (Default sort order is PSS.)" << std::endl
+              << "    -R  Reverse sort order (default is descending)." << std::endl
+              << "    -c  Only show cached (storage backed) pages" << std::endl
+              << "    -C  Only show non-cached (ram/swap backed) pages" << std::endl
+              << "    -k  Only show pages collapsed by KSM" << std::endl
+              << "    -w  Display statistics for working set only." << std::endl
+              << "    -W  Reset working set of all processes." << std::endl
+              << "    -o  Show and sort by oom score against lowmemorykiller thresholds."
+              << std::endl
+              << "    -h  Display this help screen." << std::endl;
+}
+
+static bool read_all_pids(std::vector<pid_t>* pids, std::function<bool(pid_t pid)> for_each_pid) {
+    pids->clear();
+    std::unique_ptr<DIR, int (*)(DIR*)> procdir(opendir("/proc"), closedir);
+    if (!procdir) return false;
+
+    struct dirent* dir;
+    pid_t pid;
+    while ((dir = readdir(procdir.get()))) {
+        if (!::android::base::ParseInt(dir->d_name, &pid)) continue;
+        if (!for_each_pid(pid)) return false;
+        pids->push_back(pid);
+    }
+
+    return true;
+}
+
+static bool count_swap_offsets(const ProcessRecord& proc, uint16_t* swap_offset_array,
+                               uint32_t size) {
+    const std::vector<uint16_t>& swp_offs = proc.SwapOffsets();
+    for (auto& off : swp_offs) {
+        if (off >= size) {
+            std::cerr << "swap offset " << off << " is out of bounds for process: " << proc.pid()
+                      << std::endl;
+            return false;
+        }
+
+        if (swap_offset_array[off] == USHRT_MAX) {
+            std::cerr << "swap offset " << off << " ref count overflow in process: " << proc.pid()
+                      << std::endl;
+            return false;
+        }
+
+        swap_offset_array[off]++;
+    }
+
+    return true;
+}
+
+static void print_header(std::stringstream& ss) {
+    ss.str("");
+    ss << ::android::base::StringPrintf("%5s  ", "PID");
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5s  ", "oom");
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "WRss", "WPss", "WUss");
+        // now swap statistics here, working set pages by definition shouldn't end up in swap.
+    } else {
+        ss << ::android::base::StringPrintf("%8s  %7s  %7s  %7s  ", "Vss", "Rss", "Pss", "Uss");
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "Swap", "PSwap", "USwap");
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%7s  ", "ZSwap");
+            }
+        }
+    }
+
+    ss << "cmdline";
+}
+
+static void print_process_record(std::stringstream& ss, ProcessRecord& proc) {
+    ss << ::android::base::StringPrintf("%5d  ", proc.pid());
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5d  ", proc.oomadj());
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  ",
+                                            proc.Wss().rss / 1024, proc.Wss().pss / 1024,
+                                            proc.Wss().uss / 1024);
+    } else {
+        ss << ::android::base::StringPrintf("%7" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64
+                                            "K  ",
+                                            proc.Usage().vss / 1024, proc.Usage().rss / 1024,
+                                            proc.Usage().pss / 1024, proc.Usage().uss / 1024);
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", proc.Usage().swap / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", proc.proportional_swap() / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", proc.unique_swap() / 1024);
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", (proc.zswap() / 1024));
+            }
+        }
+    }
+}
+
+static void print_processes(std::stringstream& ss, std::vector<ProcessRecord>& procs,
+                            uint16_t* swap_offset_array) {
+    for (auto& proc : procs) {
+        total_pss += show_wss ? proc.Wss().pss : proc.Usage().pss;
+        total_uss += show_wss ? proc.Wss().uss : proc.Usage().uss;
+        if (!show_wss && has_swap) {
+            proc.CalculateSwap(swap_offset_array, zram_compression_ratio);
+            total_swap += proc.Usage().swap;
+            total_pswap += proc.proportional_swap();
+            total_uswap += proc.unique_swap();
+            if (has_zram) {
+                total_zswap += proc.zswap();
+            }
+        }
+
+        print_process_record(ss, proc);
+        ss << proc.cmdline() << std::endl;
+    }
+}
+
+static void print_separator(std::stringstream& ss) {
+    ss << ::android::base::StringPrintf("%5s  ", "");
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5s  ", "");
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "", "------", "------");
+    } else {
+        ss << ::android::base::StringPrintf("%8s  %7s  %7s  %7s  ", "", "", "------", "------");
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%7s  %7s  %7s  ", "------", "------", "------");
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%7s  ", "------");
+            }
+        }
+    }
+
+    ss << ::android::base::StringPrintf("%s", "------");
+}
+
+static void print_totals(std::stringstream& ss) {
+    ss << ::android::base::StringPrintf("%5s  ", "");
+    if (show_oomadj) {
+        ss << ::android::base::StringPrintf("%5s  ", "");
+    }
+
+    if (show_wss) {
+        ss << ::android::base::StringPrintf("%7s  %6" PRIu64 "K  %6" PRIu64 "K  ", "",
+                                            total_pss / 1024, total_uss / 1024);
+    } else {
+        ss << ::android::base::StringPrintf("%8s  %7s  %6" PRIu64 "K  %6" PRIu64 "K  ", "", "",
+                                            total_pss / 1024, total_uss / 1024);
+        if (has_swap) {
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_swap / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_pswap / 1024);
+            ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_uswap / 1024);
+            if (has_zram) {
+                ss << ::android::base::StringPrintf("%6" PRIu64 "K  ", total_zswap / 1024);
+            }
+        }
+    }
+    ss << "TOTAL";
+}
+
+static void print_sysmeminfo(std::stringstream& ss, ::android::meminfo::SysMemInfo& smi) {
+    if (has_swap) {
+        ss << ::android::base::StringPrintf("ZRAM: %" PRIu64 "K physical used for %" PRIu64
+                                            "K in swap "
+                                            "(%" PRIu64 "K total swap)",
+                                            smi.mem_zram_kb(),
+                                            (smi.mem_swap_kb() - smi.mem_swap_free_kb()),
+                                            smi.mem_swap_kb())
+           << std::endl;
+    }
+
+    ss << ::android::base::StringPrintf(" RAM: %" PRIu64 "K total, %" PRIu64 "K free, %" PRIu64
+                                        "K buffers, "
+                                        "%" PRIu64 "K cached, %" PRIu64 "K shmem, %" PRIu64
+                                        "K slab",
+                                        smi.mem_total_kb(), smi.mem_free_kb(), smi.mem_buffers_kb(),
+                                        smi.mem_cached_kb(), smi.mem_shmem_kb(), smi.mem_slab_kb());
+}
+
+int main(int argc, char* argv[]) {
+    auto pss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.pss < stats_b.pss : stats_a.pss > stats_b.pss;
+    };
+
+    auto uss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.uss < stats_b.uss : stats_a.uss > stats_b.uss;
+    };
+
+    auto rss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.rss < stats_b.pss : stats_a.pss > stats_b.pss;
+    };
+
+    auto vss_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.vss < stats_b.vss : stats_a.vss > stats_b.vss;
+    };
+
+    auto swap_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        MemUsage stats_a = show_wss ? a.Wss() : a.Usage();
+        MemUsage stats_b = show_wss ? b.Wss() : b.Usage();
+        return reverse_sort ? stats_a.swap < stats_b.swap : stats_a.swap > stats_b.swap;
+    };
+
+    auto oomadj_sort = [](ProcessRecord& a, ProcessRecord& b) {
+        return reverse_sort ? a.oomadj() < b.oomadj() : a.oomadj() > b.oomadj();
+    };
+
+    // default PSS sort
+    std::function<bool(ProcessRecord & a, ProcessRecord & b)> proc_sort = pss_sort;
+
+    // count all pages by default
+    uint64_t pgflags = 0;
+    uint64_t pgflags_mask = 0;
+
+    int opt;
+    while ((opt = getopt(argc, argv, "cChkoprRsuvwW")) != -1) {
+        switch (opt) {
+            case 'c':
+                pgflags = 0;
+                pgflags_mask = (1 << KPF_SWAPBACKED);
+                break;
+            case 'C':
+                pgflags = (1 << KPF_SWAPBACKED);
+                pgflags_mask = (1 << KPF_SWAPBACKED);
+                break;
+            case 'h':
+                usage(argv[0]);
+                return 0;
+                break;
+            case 'k':
+                pgflags = (1 << KPF_KSM);
+                pgflags_mask = (1 << KPF_KSM);
+                break;
+            case 'o':
+                proc_sort = oomadj_sort;
+                show_oomadj = true;
+                break;
+            case 'p':
+                proc_sort = pss_sort;
+                break;
+            case 'r':
+                proc_sort = rss_sort;
+                break;
+            case 'R':
+                reverse_sort = true;
+                break;
+            case 's':
+                proc_sort = swap_sort;
+                break;
+            case 'u':
+                proc_sort = uss_sort;
+                break;
+            case 'v':
+                proc_sort = vss_sort;
+                break;
+            case 'w':
+                show_wss = true;
+                break;
+            case 'W':
+                reset_wss = true;
+                break;
+            default:
+                abort();
+        }
+    }
+
+    std::vector<pid_t> pids;
+    std::vector<ProcessRecord> procs;
+    if (reset_wss) {
+        if (!read_all_pids(&pids,
+                           [&](pid_t pid) -> bool { return ProcMemInfo::ResetWorkingSet(pid); })) {
+            std::cerr << "Failed to reset working set of all processes" << std::endl;
+            exit(EXIT_FAILURE);
+        }
+        // we are done, all other options passed to procrank are ignored in the presence of '-W'
+        return 0;
+    }
+
+    ::android::meminfo::SysMemInfo smi;
+    if (!smi.ReadMemInfo()) {
+        std::cerr << "Failed to get system memory info" << std::endl;
+        exit(EXIT_FAILURE);
+    }
+
+    // Figure out swap and zram
+    uint64_t swap_total = smi.mem_swap_kb() * 1024;
+    has_swap = swap_total > 0;
+    // Allocate the swap array
+    auto swap_offset_array = std::make_unique<uint16_t[]>(swap_total / getpagesize());
+    if (has_swap) {
+        has_zram = smi.mem_zram_kb() > 0;
+        if (has_zram) {
+            zram_compression_ratio = static_cast<float>(smi.mem_zram_kb()) /
+                                     (smi.mem_swap_kb() - smi.mem_swap_free_kb());
+        }
+    }
+
+    auto mark_swap_usage = [&](pid_t pid) -> bool {
+        ProcessRecord proc(pid, show_wss, pgflags, pgflags_mask);
+        if (!proc.valid()) {
+            std::cerr << "Failed to create process record for: " << pid << std::endl;
+            return false;
+        }
+
+        // Skip processes with no memory mappings
+        uint64_t vss = show_wss ? proc.Wss().vss : proc.Usage().vss;
+        if (vss == 0) return true;
+
+        // collect swap_offset counts from all processes in 1st pass
+        if (!show_wss && has_swap &&
+            !count_swap_offsets(proc, swap_offset_array.get(), swap_total / getpagesize())) {
+            std::cerr << "Failed to count swap offsets for process: " << pid << std::endl;
+            return false;
+        }
+
+        procs.push_back(std::move(proc));
+        return true;
+    };
+
+    // Get a list of all pids currently running in the system in
+    // 1st pass through all processes. Mark each swap offset used by the process as we find them
+    // for calculating proportional swap usage later.
+    if (!read_all_pids(&pids, mark_swap_usage)) {
+        std::cerr << "Failed to read all pids from the system" << std::endl;
+        exit(EXIT_FAILURE);
+    }
+
+    std::stringstream ss;
+    if (procs.empty()) {
+        // This would happen in corner cases where procrank is being run to find KSM usage on a
+        // system with no KSM and combined with working set determination as follows
+        //   procrank -w -u -k
+        //   procrank -w -s -k
+        //   procrank -w -o -k
+        ss << "<empty>" << std::endl << std::endl;
+        print_sysmeminfo(ss, smi);
+        ss << std::endl;
+        std::cout << ss.str();
+        return 0;
+    }
+
+    // Sort all process records, default is PSS descending
+    std::sort(procs.begin(), procs.end(), proc_sort);
+
+    // start dumping output in string stream
+    print_header(ss);
+    ss << std::endl;
+
+    // 2nd pass to calculate and get per process stats to add them up
+    print_processes(ss, procs, swap_offset_array.get());
+
+    // Add separator to output
+    print_separator(ss);
+    ss << std::endl;
+
+    // Add totals to output
+    print_totals(ss);
+    ss << std::endl << std::endl;
+
+    // Add system information at the end
+    print_sysmeminfo(ss, smi);
+    ss << std::endl;
+
+    // dump on the screen
+    std::cout << ss.str();
+
+    return 0;
+}
diff --git a/libmemunreachable/HeapWalker.cpp b/libmemunreachable/HeapWalker.cpp
index 2403ad0..89837f7 100644
--- a/libmemunreachable/HeapWalker.cpp
+++ b/libmemunreachable/HeapWalker.cpp
@@ -35,6 +35,13 @@
     end = begin + 1;
   }
   Range range{begin, end};
+  if (valid_mappings_range_.end != 0 &&
+      (begin < valid_mappings_range_.begin || end > valid_mappings_range_.end)) {
+    MEM_LOG_ALWAYS_FATAL("allocation %p-%p is outside mapping range %p-%p",
+                         reinterpret_cast<void*>(begin), reinterpret_cast<void*>(end),
+                         reinterpret_cast<void*>(valid_mappings_range_.begin),
+                         reinterpret_cast<void*>(valid_mappings_range_.end));
+  }
   auto inserted = allocations_.insert(std::pair<Range, AllocationInfo>(range, AllocationInfo{}));
   if (inserted.second) {
     valid_allocations_range_.begin = std::min(valid_allocations_range_.begin, begin);
@@ -76,15 +83,22 @@
     Range range = to_do.back();
     to_do.pop_back();
 
+    walking_range_ = range;
     ForEachPtrInRange(range, [&](Range& ref_range, AllocationInfo* ref_info) {
       if (!ref_info->referenced_from_root) {
         ref_info->referenced_from_root = true;
         to_do.push_back(ref_range);
       }
     });
+    walking_range_ = Range{0, 0};
   }
 }
 
+void HeapWalker::Mapping(uintptr_t begin, uintptr_t end) {
+  valid_mappings_range_.begin = std::min(valid_mappings_range_.begin, begin);
+  valid_mappings_range_.end = std::max(valid_mappings_range_.end, end);
+}
+
 void HeapWalker::Root(uintptr_t begin, uintptr_t end) {
   roots_.push_back(Range{begin, end});
 }
@@ -113,6 +127,10 @@
 
   RecurseRoot(vals);
 
+  if (segv_page_count_ > 0) {
+    MEM_ALOGE("%zu pages skipped due to segfaults", segv_page_count_);
+  }
+
   return true;
 }
 
@@ -168,7 +186,15 @@
     handler.reset();
     return;
   }
-  MEM_ALOGW("failed to read page at %p, signal %d", si->si_addr, signal);
+  if (!segv_logged_) {
+    MEM_ALOGW("failed to read page at %p, signal %d", si->si_addr, signal);
+    if (walking_range_.begin != 0U) {
+      MEM_ALOGW("while walking range %p-%p", reinterpret_cast<void*>(walking_range_.begin),
+                reinterpret_cast<void*>(walking_range_.end));
+    }
+    segv_logged_ = true;
+  }
+  segv_page_count_++;
   if (!MapOverPage(si->si_addr)) {
     handler.reset();
   }
diff --git a/libmemunreachable/HeapWalker.h b/libmemunreachable/HeapWalker.h
index 92a8325..9e3db08 100644
--- a/libmemunreachable/HeapWalker.h
+++ b/libmemunreachable/HeapWalker.h
@@ -53,9 +53,14 @@
         roots_(allocator),
         root_vals_(allocator),
         segv_handler_(),
-        walking_ptr_(0) {
+        walking_ptr_(0),
+        walking_range_{0, 0},
+        segv_logged_(false),
+        segv_page_count_(0) {
     valid_allocations_range_.end = 0;
     valid_allocations_range_.begin = ~valid_allocations_range_.end;
+    valid_mappings_range_.end = 0;
+    valid_mappings_range_.begin = ~valid_allocations_range_.end;
 
     segv_handler_.install(
         SIGSEGV, [=](ScopedSignalHandler& handler, int signal, siginfo_t* siginfo, void* uctx) {
@@ -65,6 +70,7 @@
 
   ~HeapWalker() {}
   bool Allocation(uintptr_t begin, uintptr_t end);
+  void Mapping(uintptr_t begin, uintptr_t end);
   void Root(uintptr_t begin, uintptr_t end);
   void Root(const allocator::vector<uintptr_t>& vals);
 
@@ -95,12 +101,16 @@
   AllocationMap allocations_;
   size_t allocation_bytes_;
   Range valid_allocations_range_;
+  Range valid_mappings_range_;
 
   allocator::vector<Range> roots_;
   allocator::vector<uintptr_t> root_vals_;
 
   ScopedSignalHandler segv_handler_;
-  uintptr_t walking_ptr_;
+  volatile uintptr_t walking_ptr_;
+  Range walking_range_;
+  bool segv_logged_;
+  size_t segv_page_count_;
 };
 
 template <class F>
diff --git a/libmemunreachable/MemUnreachable.cpp b/libmemunreachable/MemUnreachable.cpp
index b160de9..3d7b8a8 100644
--- a/libmemunreachable/MemUnreachable.cpp
+++ b/libmemunreachable/MemUnreachable.cpp
@@ -87,6 +87,11 @@
                                         const allocator::vector<Mapping>& mappings,
                                         const allocator::vector<uintptr_t>& refs) {
   MEM_ALOGI("searching process %d for allocations", pid_);
+
+  for (auto it = mappings.begin(); it != mappings.end(); it++) {
+    heap_walker_.Mapping(it->begin, it->end);
+  }
+
   allocator::vector<Mapping> heap_mappings{mappings};
   allocator::vector<Mapping> anon_mappings{mappings};
   allocator::vector<Mapping> globals_mappings{mappings};
diff --git a/libmemunreachable/tests/HeapWalker_test.cpp b/libmemunreachable/tests/HeapWalker_test.cpp
index 84a0ec6..9610cd6 100644
--- a/libmemunreachable/tests/HeapWalker_test.cpp
+++ b/libmemunreachable/tests/HeapWalker_test.cpp
@@ -73,6 +73,24 @@
   ASSERT_FALSE(heap_walker.Allocation(2, 3));
 }
 
+TEST_F(HeapWalkerTest, mapping) {
+  HeapWalker heap_walker(heap_);
+  heap_walker.Mapping(2, 3);
+  heap_walker.Mapping(4, 5);
+  ASSERT_TRUE(heap_walker.Allocation(2, 3));
+  ASSERT_TRUE(heap_walker.Allocation(4, 5));
+  // space between mappings is not checked, but could be in the future
+  ASSERT_TRUE(heap_walker.Allocation(3, 4));
+
+  // re-enable malloc, ASSERT_DEATH may allocate
+  disable_malloc_.Enable();
+  ASSERT_DEATH({ heap_walker.Allocation(1, 2); }, "0x1-0x2.*outside.*0x2-0x5");
+  ASSERT_DEATH({ heap_walker.Allocation(1, 3); }, "0x1-0x3.*outside.*0x2-0x5");
+  ASSERT_DEATH({ heap_walker.Allocation(4, 6); }, "0x4-0x6.*outside.*0x2-0x5");
+  ASSERT_DEATH({ heap_walker.Allocation(5, 6); }, "0x5-0x6.*outside.*0x2-0x5");
+  ASSERT_DEATH({ heap_walker.Allocation(1, 6); }, "0x1-0x6.*outside.*0x2-0x5");
+}
+
 #define buffer_begin(buffer) reinterpret_cast<uintptr_t>(buffer)
 #define buffer_end(buffer) (reinterpret_cast<uintptr_t>(buffer) + sizeof(buffer))
 
diff --git a/libprocinfo/include/procinfo/process_map.h b/libprocinfo/include/procinfo/process_map.h
index 0fc4201..981241e 100644
--- a/libprocinfo/include/procinfo/process_map.h
+++ b/libprocinfo/include/procinfo/process_map.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <stdlib.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 
diff --git a/libstats/include/stats_event_list.h b/libstats/include/stats_event_list.h
index a9832db..41ca79b 100644
--- a/libstats/include/stats_event_list.h
+++ b/libstats/include/stats_event_list.h
@@ -26,7 +26,7 @@
 int write_to_logger(android_log_context context, log_id_t id);
 void note_log_drop();
 void stats_log_close();
-
+int android_log_write_char_array(android_log_context ctx, const char* value, size_t len);
 #ifdef __cplusplus
 }
 #endif
@@ -244,6 +244,14 @@
         return ret >= 0;
     }
 
+    bool AppendCharArray(const char* value, size_t len) {
+        int retval = android_log_write_char_array(ctx, value, len);
+        if (retval < 0) {
+            ret = retval;
+        }
+        return ret >= 0;
+    }
+
     android_log_list_element read() { return android_log_read_next(ctx); }
     android_log_list_element peek() { return android_log_peek_next(ctx); }
 };
diff --git a/libstats/stats_event_list.c b/libstats/stats_event_list.c
index 72770d4..f4a7e94 100644
--- a/libstats/stats_event_list.c
+++ b/libstats/stats_event_list.c
@@ -193,3 +193,47 @@
     errno = save_errno;
     return ret;
 }
+
+static inline void copy4LE(uint8_t* buf, uint32_t val) {
+    buf[0] = val & 0xFF;
+    buf[1] = (val >> 8) & 0xFF;
+    buf[2] = (val >> 16) & 0xFF;
+    buf[3] = (val >> 24) & 0xFF;
+}
+
+// Note: this function differs from android_log_write_string8_len in that the length passed in
+// should be treated as actual length and not max length.
+int android_log_write_char_array(android_log_context ctx, const char* value, size_t actual_len) {
+    size_t needed;
+    ssize_t len = actual_len;
+    android_log_context_internal* context;
+
+    context = (android_log_context_internal*)ctx;
+    if (!context || (kAndroidLoggerWrite != context->read_write_flag)) {
+        return -EBADF;
+    }
+    if (context->overflow) {
+        return -EIO;
+    }
+    if (!value) {
+        value = "";
+        len = 0;
+    }
+    needed = sizeof(uint8_t) + sizeof(int32_t) + len;
+    if ((context->pos + needed) > MAX_EVENT_PAYLOAD) {
+        /* Truncate string for delivery */
+        len = MAX_EVENT_PAYLOAD - context->pos - 1 - sizeof(int32_t);
+        if (len <= 0) {
+            context->overflow = true;
+            return -EIO;
+        }
+    }
+    context->count[context->list_nest_depth]++;
+    context->storage[context->pos + 0] = EVENT_TYPE_STRING;
+    copy4LE(&context->storage[context->pos + 1], len);
+    if (len) {
+        memcpy(&context->storage[context->pos + 5], value, len);
+    }
+    context->pos += needed;
+    return len;
+}
diff --git a/libsysutils/Android.bp b/libsysutils/Android.bp
index 29d23c8..da5d86c 100644
--- a/libsysutils/Android.bp
+++ b/libsysutils/Android.bp
@@ -1,4 +1,4 @@
-cc_library_shared {
+cc_library {
     name: "libsysutils",
     vendor_available: true,
     vndk: {
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index 14f82c7..a5e0dc9 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -184,6 +184,7 @@
         "tests/MapInfoGetLoadBiasTest.cpp",
         "tests/MapsTest.cpp",
         "tests/MemoryBufferTest.cpp",
+        "tests/MemoryCacheTest.cpp",
         "tests/MemoryFake.cpp",
         "tests/MemoryFileTest.cpp",
         "tests/MemoryLocalTest.cpp",
@@ -310,6 +311,28 @@
     ],
 }
 
+//-------------------------------------------------------------------------
+// Benchmarks
+//-------------------------------------------------------------------------
+cc_benchmark {
+    name: "unwind_benchmarks",
+    host_supported: true,
+    defaults: ["libunwindstack_flags"],
+
+    // Disable optimizations so that all of the calls are not optimized away.
+    cflags: [
+        "-O0",
+    ],
+
+    srcs: [
+        "benchmarks/unwind_benchmarks.cpp",
+    ],
+
+    shared_libs: [
+        "libunwindstack",
+    ],
+}
+
 // Generates the elf data for use in the tests for .gnu_debugdata frames.
 // Once these files are generated, use the xz command to compress the data.
 cc_binary_host {
diff --git a/libunwindstack/Elf.cpp b/libunwindstack/Elf.cpp
index 4d72ead..5b586a2 100644
--- a/libunwindstack/Elf.cpp
+++ b/libunwindstack/Elf.cpp
@@ -140,6 +140,10 @@
   return true;
 }
 
+bool Elf::GetBuildID(std::string* build_id) {
+  return valid_ && interface_->GetBuildID(build_id);
+}
+
 void Elf::GetLastError(ErrorData* data) {
   if (valid_) {
     *data = interface_->last_error();
diff --git a/libunwindstack/ElfInterface.cpp b/libunwindstack/ElfInterface.cpp
index f59a472..d0af94a 100644
--- a/libunwindstack/ElfInterface.cpp
+++ b/libunwindstack/ElfInterface.cpp
@@ -237,6 +237,56 @@
   }
 }
 
+template <typename NhdrType>
+bool ElfInterface::ReadBuildID(std::string* build_id) {
+  // Ensure there is no overflow in any of the calulations below.
+  uint64_t tmp;
+  if (__builtin_add_overflow(gnu_build_id_offset_, gnu_build_id_size_, &tmp)) {
+    return false;
+  }
+
+  uint64_t offset = 0;
+  while (offset < gnu_build_id_size_) {
+    if (gnu_build_id_size_ - offset < sizeof(NhdrType)) {
+      return false;
+    }
+    NhdrType hdr;
+    if (!memory_->ReadFully(gnu_build_id_offset_ + offset, &hdr, sizeof(hdr))) {
+      return false;
+    }
+    offset += sizeof(hdr);
+
+    if (gnu_build_id_size_ - offset < hdr.n_namesz) {
+      return false;
+    }
+    if (hdr.n_namesz > 0) {
+      std::string name(hdr.n_namesz, '\0');
+      if (!memory_->ReadFully(gnu_build_id_offset_ + offset, &(name[0]), hdr.n_namesz)) {
+        return false;
+      }
+
+      // Trim trailing \0 as GNU is stored as a C string in the ELF file.
+      if (name.back() == '\0')
+        name.resize(name.size() - 1);
+
+      // Align hdr.n_namesz to next power multiple of 4. See man 5 elf.
+      offset += (hdr.n_namesz + 3) & ~3;
+
+      if (name == "GNU" && hdr.n_type == NT_GNU_BUILD_ID) {
+        if (gnu_build_id_size_ - offset < hdr.n_descsz) {
+          return false;
+        }
+        build_id->resize(hdr.n_descsz);
+        return memory_->ReadFully(gnu_build_id_offset_ + offset, &(*build_id)[0],
+                                  hdr.n_descsz);
+      }
+    }
+    // Align hdr.n_descsz to next power multiple of 4. See man 5 elf.
+    offset += (hdr.n_descsz + 3) & ~3;
+  }
+  return false;
+}
+
 template <typename EhdrType, typename ShdrType>
 void ElfInterface::ReadSectionHeaders(const EhdrType& ehdr) {
   uint64_t offset = ehdr.e_shoff;
@@ -308,6 +358,15 @@
       // In order to read soname, keep track of address to offset mapping.
       strtabs_.push_back(std::make_pair<uint64_t, uint64_t>(static_cast<uint64_t>(shdr.sh_addr),
                                                             static_cast<uint64_t>(shdr.sh_offset)));
+    } else if (shdr.sh_type == SHT_NOTE) {
+      if (shdr.sh_name < sec_size) {
+        std::string name;
+        if (memory_->ReadString(sec_offset + shdr.sh_name, &name) &&
+            name == ".note.gnu.build-id") {
+          gnu_build_id_offset_ = shdr.sh_offset;
+          gnu_build_id_size_ = shdr.sh_size;
+        }
+      }
     }
   }
 }
@@ -492,6 +551,9 @@
 template void ElfInterface::ReadSectionHeaders<Elf32_Ehdr, Elf32_Shdr>(const Elf32_Ehdr&);
 template void ElfInterface::ReadSectionHeaders<Elf64_Ehdr, Elf64_Shdr>(const Elf64_Ehdr&);
 
+template bool ElfInterface::ReadBuildID<Elf32_Nhdr>(std::string*);
+template bool ElfInterface::ReadBuildID<Elf64_Nhdr>(std::string*);
+
 template bool ElfInterface::GetSonameWithTemplate<Elf32_Dyn>(std::string*);
 template bool ElfInterface::GetSonameWithTemplate<Elf64_Dyn>(std::string*);
 
diff --git a/libunwindstack/Global.cpp b/libunwindstack/Global.cpp
index 7a3de01..fdfd705 100644
--- a/libunwindstack/Global.cpp
+++ b/libunwindstack/Global.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdint.h>
+#include <string.h>
 #include <sys/mman.h>
 
 #include <string>
diff --git a/libunwindstack/Maps.cpp b/libunwindstack/Maps.cpp
index 8729871..a9fb859 100644
--- a/libunwindstack/Maps.cpp
+++ b/libunwindstack/Maps.cpp
@@ -19,6 +19,7 @@
 #include <inttypes.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <unistd.h>
diff --git a/libunwindstack/Memory.cpp b/libunwindstack/Memory.cpp
index cfa8c6d..9904fef 100644
--- a/libunwindstack/Memory.cpp
+++ b/libunwindstack/Memory.cpp
@@ -16,6 +16,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/ptrace.h>
 #include <sys/stat.h>
@@ -174,6 +175,13 @@
   return std::shared_ptr<Memory>(new MemoryRemote(pid));
 }
 
+std::shared_ptr<Memory> Memory::CreateProcessMemoryCached(pid_t pid) {
+  if (pid == getpid()) {
+    return std::shared_ptr<Memory>(new MemoryCache(new MemoryLocal()));
+  }
+  return std::shared_ptr<Memory>(new MemoryCache(new MemoryRemote(pid)));
+}
+
 size_t MemoryBuffer::Read(uint64_t addr, void* dst, size_t size) {
   if (addr >= raw_.size()) {
     return 0;
@@ -398,4 +406,50 @@
   return 0;
 }
 
+size_t MemoryCache::Read(uint64_t addr, void* dst, size_t size) {
+  // Only bother caching and looking at the cache if this is a small read for now.
+  if (size > 64) {
+    return impl_->Read(addr, dst, size);
+  }
+
+  uint64_t addr_page = addr >> kCacheBits;
+  auto entry = cache_.find(addr_page);
+  uint8_t* cache_dst;
+  if (entry != cache_.end()) {
+    cache_dst = entry->second;
+  } else {
+    cache_dst = cache_[addr_page];
+    if (!impl_->ReadFully(addr_page << kCacheBits, cache_dst, kCacheSize)) {
+      // Erase the entry.
+      cache_.erase(addr_page);
+      return impl_->Read(addr, dst, size);
+    }
+  }
+  size_t max_read = ((addr_page + 1) << kCacheBits) - addr;
+  if (size <= max_read) {
+    memcpy(dst, &cache_dst[addr & kCacheMask], size);
+    return size;
+  }
+
+  // The read crossed into another cached entry, since a read can only cross
+  // into one extra cached page, duplicate the code rather than looping.
+  memcpy(dst, &cache_dst[addr & kCacheMask], max_read);
+  dst = &reinterpret_cast<uint8_t*>(dst)[max_read];
+  addr_page++;
+
+  entry = cache_.find(addr_page);
+  if (entry != cache_.end()) {
+    cache_dst = entry->second;
+  } else {
+    cache_dst = cache_[addr_page];
+    if (!impl_->ReadFully(addr_page << kCacheBits, cache_dst, kCacheSize)) {
+      // Erase the entry.
+      cache_.erase(addr_page);
+      return impl_->Read(addr_page << kCacheBits, dst, size - max_read) + max_read;
+    }
+  }
+  memcpy(dst, cache_dst, size - max_read);
+  return size;
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/RegsArm.cpp b/libunwindstack/RegsArm.cpp
index de22bde..885dc94 100644
--- a/libunwindstack/RegsArm.cpp
+++ b/libunwindstack/RegsArm.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdint.h>
+#include <string.h>
 
 #include <functional>
 
diff --git a/libunwindstack/RegsArm64.cpp b/libunwindstack/RegsArm64.cpp
index a68f6e0..e9787aa 100644
--- a/libunwindstack/RegsArm64.cpp
+++ b/libunwindstack/RegsArm64.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdint.h>
+#include <string.h>
 
 #include <functional>
 
diff --git a/libunwindstack/RegsMips.cpp b/libunwindstack/RegsMips.cpp
index 2e6908c..14a4e31 100644
--- a/libunwindstack/RegsMips.cpp
+++ b/libunwindstack/RegsMips.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdint.h>
+#include <string.h>
 
 #include <functional>
 
diff --git a/libunwindstack/RegsMips64.cpp b/libunwindstack/RegsMips64.cpp
index 0b835a1..3f67d92 100644
--- a/libunwindstack/RegsMips64.cpp
+++ b/libunwindstack/RegsMips64.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdint.h>
+#include <string.h>
 
 #include <functional>
 
diff --git a/libunwindstack/RegsX86_64.cpp b/libunwindstack/RegsX86_64.cpp
index ebad3f4..74cd1cb 100644
--- a/libunwindstack/RegsX86_64.cpp
+++ b/libunwindstack/RegsX86_64.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdint.h>
+#include <string.h>
 
 #include <functional>
 
diff --git a/libunwindstack/Symbols.cpp b/libunwindstack/Symbols.cpp
index 14ebdbb..e3c15a2 100644
--- a/libunwindstack/Symbols.cpp
+++ b/libunwindstack/Symbols.cpp
@@ -17,6 +17,7 @@
 #include <elf.h>
 #include <stdint.h>
 
+#include <algorithm>
 #include <string>
 
 #include <unwindstack/Memory.h>
diff --git a/libunwindstack/benchmarks/unwind_benchmarks.cpp b/libunwindstack/benchmarks/unwind_benchmarks.cpp
new file mode 100644
index 0000000..db0fb54
--- /dev/null
+++ b/libunwindstack/benchmarks/unwind_benchmarks.cpp
@@ -0,0 +1,83 @@
+/*
+ * 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 <stdint.h>
+
+#include <memory>
+
+#include <benchmark/benchmark.h>
+
+#include <unwindstack/Maps.h>
+#include <unwindstack/Memory.h>
+#include <unwindstack/Regs.h>
+#include <unwindstack/RegsGetLocal.h>
+#include <unwindstack/Unwinder.h>
+
+size_t Call6(std::shared_ptr<unwindstack::Memory>& process_memory, unwindstack::Maps* maps) {
+  std::unique_ptr<unwindstack::Regs> regs(unwindstack::Regs::CreateFromLocal());
+  unwindstack::RegsGetLocal(regs.get());
+  unwindstack::Unwinder unwinder(32, maps, regs.get(), process_memory);
+  unwinder.Unwind();
+  return unwinder.NumFrames();
+}
+
+size_t Call5(std::shared_ptr<unwindstack::Memory>& process_memory, unwindstack::Maps* maps) {
+  return Call6(process_memory, maps);
+}
+
+size_t Call4(std::shared_ptr<unwindstack::Memory>& process_memory, unwindstack::Maps* maps) {
+  return Call5(process_memory, maps);
+}
+
+size_t Call3(std::shared_ptr<unwindstack::Memory>& process_memory, unwindstack::Maps* maps) {
+  return Call4(process_memory, maps);
+}
+
+size_t Call2(std::shared_ptr<unwindstack::Memory>& process_memory, unwindstack::Maps* maps) {
+  return Call3(process_memory, maps);
+}
+
+size_t Call1(std::shared_ptr<unwindstack::Memory>& process_memory, unwindstack::Maps* maps) {
+  return Call2(process_memory, maps);
+}
+
+static void BM_uncached_unwind(benchmark::State& state) {
+  auto process_memory = unwindstack::Memory::CreateProcessMemory(getpid());
+  unwindstack::LocalMaps maps;
+  if (!maps.Parse()) {
+    state.SkipWithError("Failed to parse local maps.");
+  }
+
+  for (auto _ : state) {
+    benchmark::DoNotOptimize(Call1(process_memory, &maps));
+  }
+}
+BENCHMARK(BM_uncached_unwind);
+
+static void BM_cached_unwind(benchmark::State& state) {
+  auto process_memory = unwindstack::Memory::CreateProcessMemoryCached(getpid());
+  unwindstack::LocalMaps maps;
+  if (!maps.Parse()) {
+    state.SkipWithError("Failed to parse local maps.");
+  }
+
+  for (auto _ : state) {
+    benchmark::DoNotOptimize(Call1(process_memory, &maps));
+  }
+}
+BENCHMARK(BM_cached_unwind);
+
+BENCHMARK_MAIN();
diff --git a/libunwindstack/include/unwindstack/Elf.h b/libunwindstack/include/unwindstack/Elf.h
index e5b0a89..27f7201 100644
--- a/libunwindstack/include/unwindstack/Elf.h
+++ b/libunwindstack/include/unwindstack/Elf.h
@@ -65,6 +65,8 @@
 
   bool GetGlobalVariable(const std::string& name, uint64_t* memory_address);
 
+  bool GetBuildID(std::string* build_id);
+
   uint64_t GetRelPc(uint64_t pc, const MapInfo* map_info);
 
   bool Step(uint64_t rel_pc, uint64_t adjusted_rel_pc, Regs* regs, Memory* process_memory,
diff --git a/libunwindstack/include/unwindstack/ElfInterface.h b/libunwindstack/include/unwindstack/ElfInterface.h
index a45eba8..52992d9 100644
--- a/libunwindstack/include/unwindstack/ElfInterface.h
+++ b/libunwindstack/include/unwindstack/ElfInterface.h
@@ -62,6 +62,8 @@
 
   virtual bool GetGlobalVariable(const std::string& name, uint64_t* memory_address) = 0;
 
+  virtual bool GetBuildID(std::string* build_id) = 0;
+
   virtual bool Step(uint64_t rel_pc, Regs* regs, Memory* process_memory, bool* finished);
 
   virtual bool IsValidPc(uint64_t pc);
@@ -85,6 +87,8 @@
   uint64_t debug_frame_size() { return debug_frame_size_; }
   uint64_t gnu_debugdata_offset() { return gnu_debugdata_offset_; }
   uint64_t gnu_debugdata_size() { return gnu_debugdata_size_; }
+  uint64_t gnu_build_id_offset() { return gnu_build_id_offset_; }
+  uint64_t gnu_build_id_size() { return gnu_build_id_size_; }
 
   DwarfSection* eh_frame() { return eh_frame_.get(); }
   DwarfSection* debug_frame() { return debug_frame_.get(); }
@@ -123,6 +127,9 @@
   template <typename EhdrType>
   static void GetMaxSizeWithTemplate(Memory* memory, uint64_t* size);
 
+  template <typename NhdrType>
+  bool ReadBuildID(std::string* build_id);
+
   Memory* memory_;
   std::unordered_map<uint64_t, LoadInfo> pt_loads_;
 
@@ -143,6 +150,9 @@
   uint64_t gnu_debugdata_offset_ = 0;
   uint64_t gnu_debugdata_size_ = 0;
 
+  uint64_t gnu_build_id_offset_ = 0;
+  uint64_t gnu_build_id_size_ = 0;
+
   uint8_t soname_type_ = SONAME_UNKNOWN;
   std::string soname_;
 
@@ -182,6 +192,10 @@
     return ElfInterface::GetGlobalVariableWithTemplate<Elf32_Sym>(name, memory_address);
   }
 
+  bool GetBuildID(std::string* build_id) {
+    return ElfInterface::ReadBuildID<Elf32_Nhdr>(build_id);
+  }
+
   static void GetMaxSize(Memory* memory, uint64_t* size) {
     GetMaxSizeWithTemplate<Elf32_Ehdr>(memory, size);
   }
@@ -212,6 +226,10 @@
     return ElfInterface::GetGlobalVariableWithTemplate<Elf64_Sym>(name, memory_address);
   }
 
+  bool GetBuildID(std::string* build_id) {
+    return ElfInterface::ReadBuildID<Elf64_Nhdr>(build_id);
+  }
+
   static void GetMaxSize(Memory* memory, uint64_t* size) {
     GetMaxSizeWithTemplate<Elf64_Ehdr>(memory, size);
   }
diff --git a/libunwindstack/include/unwindstack/Memory.h b/libunwindstack/include/unwindstack/Memory.h
index 9c425cb..dba41d1 100644
--- a/libunwindstack/include/unwindstack/Memory.h
+++ b/libunwindstack/include/unwindstack/Memory.h
@@ -25,6 +25,7 @@
 #include <map>
 #include <memory>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
 namespace unwindstack {
@@ -35,9 +36,12 @@
   virtual ~Memory() = default;
 
   static std::shared_ptr<Memory> CreateProcessMemory(pid_t pid);
+  static std::shared_ptr<Memory> CreateProcessMemoryCached(pid_t pid);
 
   virtual bool ReadString(uint64_t addr, std::string* string, uint64_t max_read = UINT64_MAX);
 
+  virtual void Clear() {}
+
   virtual size_t Read(uint64_t addr, void* dst, size_t size) = 0;
 
   bool ReadFully(uint64_t addr, void* dst, size_t size);
@@ -51,6 +55,24 @@
   }
 };
 
+class MemoryCache : public Memory {
+ public:
+  MemoryCache(Memory* memory) : impl_(memory) {}
+  virtual ~MemoryCache() = default;
+
+  size_t Read(uint64_t addr, void* dst, size_t size) override;
+
+  void Clear() override { cache_.clear(); }
+
+ private:
+  constexpr static size_t kCacheBits = 12;
+  constexpr static size_t kCacheMask = (1 << kCacheBits) - 1;
+  constexpr static size_t kCacheSize = 1 << kCacheBits;
+  std::unordered_map<uint64_t, uint8_t[kCacheSize]> cache_;
+
+  std::unique_ptr<Memory> impl_;
+};
+
 class MemoryBuffer : public Memory {
  public:
   MemoryBuffer() = default;
diff --git a/libunwindstack/tests/ElfFake.h b/libunwindstack/tests/ElfFake.h
index a3bf5ce..c2bd0f6 100644
--- a/libunwindstack/tests/ElfFake.h
+++ b/libunwindstack/tests/ElfFake.h
@@ -72,6 +72,9 @@
 
   bool GetFunctionName(uint64_t, std::string*, uint64_t*) override;
   bool GetGlobalVariable(const std::string&, uint64_t*) override;
+  bool GetBuildID(std::string*) override {
+    return false;
+  }
 
   bool Step(uint64_t, Regs*, Memory*, bool*) override;
 
diff --git a/libunwindstack/tests/ElfInterfaceTest.cpp b/libunwindstack/tests/ElfInterfaceTest.cpp
index 9326bff..6023dc4 100644
--- a/libunwindstack/tests/ElfInterfaceTest.cpp
+++ b/libunwindstack/tests/ElfInterfaceTest.cpp
@@ -116,6 +116,21 @@
   void InitSym(uint64_t offset, uint32_t value, uint32_t size, uint32_t name_offset,
                uint64_t sym_offset, const char* name);
 
+  template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+  void BuildID();
+
+  template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+  void BuildIDTwoNotes();
+
+  template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+  void BuildIDSectionTooSmallForName();
+
+  template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+  void BuildIDSectionTooSmallForDesc();
+
+  template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+  void BuildIDSectionTooSmallForHeader();
+
   MemoryFake memory_;
 };
 
@@ -898,7 +913,7 @@
 
   Ehdr ehdr = {};
   ehdr.e_shoff = offset;
-  ehdr.e_shnum = 6;
+  ehdr.e_shnum = 7;
   ehdr.e_shentsize = sizeof(Shdr);
   ehdr.e_shstrndx = 2;
   memory_.SetMemory(0, &ehdr, sizeof(ehdr));
@@ -958,10 +973,19 @@
   memory_.SetMemory(offset, &shdr, sizeof(shdr));
   offset += ehdr.e_shentsize;
 
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_NOTE;
+  shdr.sh_name = 0x500;
+  shdr.sh_offset = 0xb000;
+  shdr.sh_size = 0xf00;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
   memory_.SetMemory(0xf100, ".debug_frame", sizeof(".debug_frame"));
   memory_.SetMemory(0xf200, ".gnu_debugdata", sizeof(".gnu_debugdata"));
   memory_.SetMemory(0xf300, ".eh_frame", sizeof(".eh_frame"));
   memory_.SetMemory(0xf400, ".eh_frame_hdr", sizeof(".eh_frame_hdr"));
+  memory_.SetMemory(0xf500, ".note.gnu.build-id", sizeof(".note.gnu.build-id"));
 
   uint64_t load_bias = 0;
   ASSERT_TRUE(elf->Init(&load_bias));
@@ -974,6 +998,8 @@
   EXPECT_EQ(0x800U, elf->eh_frame_size());
   EXPECT_EQ(0xa000U, elf->eh_frame_hdr_offset());
   EXPECT_EQ(0xf00U, elf->eh_frame_hdr_size());
+  EXPECT_EQ(0xb000U, elf->gnu_build_id_offset());
+  EXPECT_EQ(0xf00U, elf->gnu_build_id_size());
 }
 
 TEST_F(ElfInterfaceTest, init_section_headers_offsets32) {
@@ -1153,4 +1179,321 @@
   EXPECT_FALSE(elf->IsValidPc(0x2a00));
 }
 
+template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+void ElfInterfaceTest::BuildID() {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x2000;
+
+  Ehdr ehdr = {};
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 3;
+  ehdr.e_shentsize = sizeof(Shdr);
+  ehdr.e_shstrndx = 2;
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  char note_section[128];
+  Nhdr note_header = {};
+  note_header.n_namesz = 4;  // "GNU"
+  note_header.n_descsz = 8; // "BUILDID"
+  note_header.n_type = NT_GNU_BUILD_ID;
+  memcpy(&note_section, &note_header, sizeof(note_header));
+  size_t note_offset = sizeof(note_header);
+  memcpy(&note_section[note_offset], "GNU", sizeof("GNU"));
+  note_offset += sizeof("GNU");
+  memcpy(&note_section[note_offset], "BUILDID", sizeof("BUILDID"));
+  note_offset += sizeof("BUILDID");
+
+  Shdr shdr = {};
+  shdr.sh_type = SHT_NOTE;
+  shdr.sh_name = 0x500;
+  shdr.sh_offset = 0xb000;
+  shdr.sh_size = sizeof(note_section);
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for section header names.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memory_.SetMemory(0xf500, ".note.gnu.build-id", sizeof(".note.gnu.build-id"));
+  memory_.SetMemory(0xb000, note_section, sizeof(note_section));
+
+  uint64_t load_bias = 0;
+  ASSERT_TRUE(elf->Init(&load_bias));
+  std::string build_id;
+  ASSERT_TRUE(elf->GetBuildID(&build_id));
+  EXPECT_STREQ(build_id.c_str(), "BUILDID");
+}
+
+template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+void ElfInterfaceTest::BuildIDTwoNotes() {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x2000;
+
+  Ehdr ehdr = {};
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 3;
+  ehdr.e_shentsize = sizeof(Shdr);
+  ehdr.e_shstrndx = 2;
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  char note_section[128];
+  Nhdr note_header = {};
+  note_header.n_namesz = 8;  // "WRONG" aligned to 4
+  note_header.n_descsz = 8; // "BUILDID"
+  note_header.n_type = NT_GNU_BUILD_ID;
+  memcpy(&note_section, &note_header, sizeof(note_header));
+  size_t note_offset = sizeof(note_header);
+  memcpy(&note_section[note_offset], "WRONG", sizeof("WRONG"));
+  note_offset += 8;
+  memcpy(&note_section[note_offset], "BUILDID", sizeof("BUILDID"));
+  note_offset += sizeof("BUILDID");
+
+  note_header.n_namesz = 4;  // "GNU"
+  note_header.n_descsz = 8; // "BUILDID"
+  note_header.n_type = NT_GNU_BUILD_ID;
+  memcpy(&note_section[note_offset], &note_header, sizeof(note_header));
+  note_offset += sizeof(note_header);
+  memcpy(&note_section[note_offset], "GNU", sizeof("GNU"));
+  note_offset += sizeof("GNU");
+  memcpy(&note_section[note_offset], "BUILDID", sizeof("BUILDID"));
+  note_offset += sizeof("BUILDID");
+
+  Shdr shdr = {};
+  shdr.sh_type = SHT_NOTE;
+  shdr.sh_name = 0x500;
+  shdr.sh_offset = 0xb000;
+  shdr.sh_size = sizeof(note_section);
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for section header names.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memory_.SetMemory(0xf500, ".note.gnu.build-id", sizeof(".note.gnu.build-id"));
+  memory_.SetMemory(0xb000, note_section, sizeof(note_section));
+
+  uint64_t load_bias = 0;
+  ASSERT_TRUE(elf->Init(&load_bias));
+  std::string build_id;
+  ASSERT_TRUE(elf->GetBuildID(&build_id));
+  EXPECT_STREQ(build_id.c_str(), "BUILDID");
+}
+
+template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+void ElfInterfaceTest::BuildIDSectionTooSmallForName () {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x2000;
+
+  Ehdr ehdr = {};
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 3;
+  ehdr.e_shentsize = sizeof(Shdr);
+  ehdr.e_shstrndx = 2;
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  char note_section[128];
+  Nhdr note_header = {};
+  note_header.n_namesz = 4;  // "GNU"
+  note_header.n_descsz = 8; // "BUILDID"
+  note_header.n_type = NT_GNU_BUILD_ID;
+  memcpy(&note_section, &note_header, sizeof(note_header));
+  size_t note_offset = sizeof(note_header);
+  memcpy(&note_section[note_offset], "GNU", sizeof("GNU"));
+  note_offset += sizeof("GNU");
+  memcpy(&note_section[note_offset], "BUILDID", sizeof("BUILDID"));
+  note_offset += sizeof("BUILDID");
+
+  Shdr shdr = {};
+  shdr.sh_type = SHT_NOTE;
+  shdr.sh_name = 0x500;
+  shdr.sh_offset = 0xb000;
+  shdr.sh_size = sizeof(note_header) + 1;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for section header names.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memory_.SetMemory(0xf500, ".note.gnu.build-id", sizeof(".note.gnu.build-id"));
+  memory_.SetMemory(0xb000, note_section, sizeof(note_section));
+
+  uint64_t load_bias = 0;
+  ASSERT_TRUE(elf->Init(&load_bias));
+  std::string build_id;
+  ASSERT_FALSE(elf->GetBuildID(&build_id));
+}
+
+template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+void ElfInterfaceTest::BuildIDSectionTooSmallForDesc () {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x2000;
+
+  Ehdr ehdr = {};
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 3;
+  ehdr.e_shentsize = sizeof(Shdr);
+  ehdr.e_shstrndx = 2;
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  char note_section[128];
+  Nhdr note_header = {};
+  note_header.n_namesz = 4;  // "GNU"
+  note_header.n_descsz = 8; // "BUILDID"
+  note_header.n_type = NT_GNU_BUILD_ID;
+  memcpy(&note_section, &note_header, sizeof(note_header));
+  size_t note_offset = sizeof(note_header);
+  memcpy(&note_section[note_offset], "GNU", sizeof("GNU"));
+  note_offset += sizeof("GNU");
+  memcpy(&note_section[note_offset], "BUILDID", sizeof("BUILDID"));
+  note_offset += sizeof("BUILDID");
+
+  Shdr shdr = {};
+  shdr.sh_type = SHT_NOTE;
+  shdr.sh_name = 0x500;
+  shdr.sh_offset = 0xb000;
+  shdr.sh_size = sizeof(note_header) + sizeof("GNU") + 1;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for section header names.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memory_.SetMemory(0xf500, ".note.gnu.build-id", sizeof(".note.gnu.build-id"));
+  memory_.SetMemory(0xb000, note_section, sizeof(note_section));
+
+  uint64_t load_bias = 0;
+  ASSERT_TRUE(elf->Init(&load_bias));
+  std::string build_id;
+  ASSERT_FALSE(elf->GetBuildID(&build_id));
+}
+
+template <typename Ehdr, typename Shdr, typename Nhdr, typename ElfInterfaceType>
+void ElfInterfaceTest::BuildIDSectionTooSmallForHeader () {
+  std::unique_ptr<ElfInterfaceType> elf(new ElfInterfaceType(&memory_));
+
+  uint64_t offset = 0x2000;
+
+  Ehdr ehdr = {};
+  ehdr.e_shoff = offset;
+  ehdr.e_shnum = 3;
+  ehdr.e_shentsize = sizeof(Shdr);
+  ehdr.e_shstrndx = 2;
+  memory_.SetMemory(0, &ehdr, sizeof(ehdr));
+
+  offset += ehdr.e_shentsize;
+
+  char note_section[128];
+  Nhdr note_header = {};
+  note_header.n_namesz = 4;  // "GNU"
+  note_header.n_descsz = 8; // "BUILDID"
+  note_header.n_type = NT_GNU_BUILD_ID;
+  memcpy(&note_section, &note_header, sizeof(note_header));
+  size_t note_offset = sizeof(note_header);
+  memcpy(&note_section[note_offset], "GNU", sizeof("GNU"));
+  note_offset += sizeof("GNU");
+  memcpy(&note_section[note_offset], "BUILDID", sizeof("BUILDID"));
+  note_offset += sizeof("BUILDID");
+
+  Shdr shdr = {};
+  shdr.sh_type = SHT_NOTE;
+  shdr.sh_name = 0x500;
+  shdr.sh_offset = 0xb000;
+  shdr.sh_size = sizeof(note_header) - 1;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  // The string data for section header names.
+  memset(&shdr, 0, sizeof(shdr));
+  shdr.sh_type = SHT_STRTAB;
+  shdr.sh_name = 0x20000;
+  shdr.sh_offset = 0xf000;
+  shdr.sh_size = 0x1000;
+  memory_.SetMemory(offset, &shdr, sizeof(shdr));
+  offset += ehdr.e_shentsize;
+
+  memory_.SetMemory(0xf500, ".note.gnu.build-id", sizeof(".note.gnu.build-id"));
+  memory_.SetMemory(0xb000, note_section, sizeof(note_section));
+
+  uint64_t load_bias = 0;
+  ASSERT_TRUE(elf->Init(&load_bias));
+  std::string build_id;
+  ASSERT_FALSE(elf->GetBuildID(&build_id));
+}
+
+TEST_F(ElfInterfaceTest, build_id32) {
+  BuildID<Elf32_Ehdr, Elf32_Shdr, Elf32_Nhdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, build_id64) {
+  BuildID<Elf64_Ehdr, Elf64_Shdr, Elf64_Nhdr, ElfInterface64>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_two_notes32) {
+  BuildIDTwoNotes<Elf32_Ehdr, Elf32_Shdr, Elf32_Nhdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_two_notes64) {
+  BuildIDTwoNotes<Elf64_Ehdr, Elf64_Shdr, Elf64_Nhdr, ElfInterface64>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_section_too_small_for_name32) {
+  BuildIDSectionTooSmallForName<Elf32_Ehdr, Elf32_Shdr, Elf32_Nhdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_section_too_small_for_name64) {
+  BuildIDSectionTooSmallForName<Elf64_Ehdr, Elf64_Shdr, Elf64_Nhdr, ElfInterface64>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_section_too_small_for_desc32) {
+  BuildIDSectionTooSmallForDesc<Elf32_Ehdr, Elf32_Shdr, Elf32_Nhdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_section_too_small_for_desc64) {
+  BuildIDSectionTooSmallForDesc<Elf64_Ehdr, Elf64_Shdr, Elf64_Nhdr, ElfInterface64>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_section_too_small_for_header32) {
+  BuildIDSectionTooSmallForHeader<Elf32_Ehdr, Elf32_Shdr, Elf32_Nhdr, ElfInterface32>();
+}
+
+TEST_F(ElfInterfaceTest, build_id_section_too_small_for_header64) {
+  BuildIDSectionTooSmallForHeader<Elf64_Ehdr, Elf64_Shdr, Elf64_Nhdr, ElfInterface64>();
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index ccf8927..7766218 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -311,6 +311,7 @@
   void InitHeaders(uint64_t) override {}
   bool GetSoname(std::string*) override { return false; }
   bool GetFunctionName(uint64_t, std::string*, uint64_t*) override { return false; }
+  bool GetBuildID(std::string*) override { return false; }
 
   MOCK_METHOD4(Step, bool(uint64_t, Regs*, Memory*, bool*));
   MOCK_METHOD2(GetGlobalVariable, bool(const std::string&, uint64_t*));
diff --git a/libunwindstack/tests/MemoryCacheTest.cpp b/libunwindstack/tests/MemoryCacheTest.cpp
new file mode 100644
index 0000000..a3def20
--- /dev/null
+++ b/libunwindstack/tests/MemoryCacheTest.cpp
@@ -0,0 +1,143 @@
+/*
+ * 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 <stdint.h>
+
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#include <unwindstack/Memory.h>
+
+#include "MemoryFake.h"
+
+namespace unwindstack {
+
+class MemoryCacheTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    memory_ = new MemoryFake;
+    memory_cache_.reset(new MemoryCache(memory_));
+
+    memory_->SetMemoryBlock(0x8000, 4096, 0xab);
+    memory_->SetMemoryBlock(0x9000, 4096, 0xde);
+    memory_->SetMemoryBlock(0xa000, 3000, 0x50);
+  }
+
+  MemoryFake* memory_;
+  std::unique_ptr<MemoryCache> memory_cache_;
+
+  constexpr static size_t kMaxCachedSize = 64;
+};
+
+TEST_F(MemoryCacheTest, cached_read) {
+  for (size_t i = 1; i <= kMaxCachedSize; i++) {
+    std::vector<uint8_t> buffer(i);
+    ASSERT_TRUE(memory_cache_->ReadFully(0x8000 + i, buffer.data(), i))
+        << "Read failed at size " << i;
+    ASSERT_EQ(std::vector<uint8_t>(i, 0xab), buffer) << "Failed at size " << i;
+  }
+
+  // Verify the cached data is used.
+  memory_->SetMemoryBlock(0x8000, 4096, 0xff);
+  for (size_t i = 1; i <= kMaxCachedSize; i++) {
+    std::vector<uint8_t> buffer(i);
+    ASSERT_TRUE(memory_cache_->ReadFully(0x8000 + i, buffer.data(), i))
+        << "Read failed at size " << i;
+    ASSERT_EQ(std::vector<uint8_t>(i, 0xab), buffer) << "Failed at size " << i;
+  }
+}
+
+TEST_F(MemoryCacheTest, no_cached_read_after_clear) {
+  for (size_t i = 1; i <= kMaxCachedSize; i++) {
+    std::vector<uint8_t> buffer(i);
+    ASSERT_TRUE(memory_cache_->ReadFully(0x8000 + i, buffer.data(), i))
+        << "Read failed at size " << i;
+    ASSERT_EQ(std::vector<uint8_t>(i, 0xab), buffer) << "Failed at size " << i;
+  }
+
+  // Verify the cached data is not used after a reset.
+  memory_cache_->Clear();
+  memory_->SetMemoryBlock(0x8000, 4096, 0xff);
+  for (size_t i = 1; i <= kMaxCachedSize; i++) {
+    std::vector<uint8_t> buffer(i);
+    ASSERT_TRUE(memory_cache_->ReadFully(0x8000 + i, buffer.data(), i))
+        << "Read failed at size " << i;
+    ASSERT_EQ(std::vector<uint8_t>(i, 0xff), buffer) << "Failed at size " << i;
+  }
+}
+
+TEST_F(MemoryCacheTest, cached_read_across_caches) {
+  std::vector<uint8_t> expect(16, 0xab);
+  expect.resize(32, 0xde);
+
+  std::vector<uint8_t> buffer(32);
+  ASSERT_TRUE(memory_cache_->ReadFully(0x8ff0, buffer.data(), 32));
+  ASSERT_EQ(expect, buffer);
+
+  // Verify the cached data is used.
+  memory_->SetMemoryBlock(0x8000, 4096, 0xff);
+  memory_->SetMemoryBlock(0x9000, 4096, 0xff);
+  ASSERT_TRUE(memory_cache_->ReadFully(0x8ff0, buffer.data(), 32));
+  ASSERT_EQ(expect, buffer);
+}
+
+TEST_F(MemoryCacheTest, no_cache_read) {
+  for (size_t i = kMaxCachedSize + 1; i < 2 * kMaxCachedSize; i++) {
+    std::vector<uint8_t> buffer(i);
+    ASSERT_TRUE(memory_cache_->ReadFully(0x8000 + i, buffer.data(), i))
+        << "Read failed at size " << i;
+    ASSERT_EQ(std::vector<uint8_t>(i, 0xab), buffer) << "Failed at size " << i;
+  }
+
+  // Verify the cached data is not used.
+  memory_->SetMemoryBlock(0x8000, 4096, 0xff);
+  for (size_t i = kMaxCachedSize + 1; i < 2 * kMaxCachedSize; i++) {
+    std::vector<uint8_t> buffer(i);
+    ASSERT_TRUE(memory_cache_->ReadFully(0x8000 + i, buffer.data(), i))
+        << "Read failed at size " << i;
+    ASSERT_EQ(std::vector<uint8_t>(i, 0xff), buffer) << "Failed at size " << i;
+  }
+}
+
+TEST_F(MemoryCacheTest, read_for_cache_fail) {
+  std::vector<uint8_t> buffer(kMaxCachedSize);
+  ASSERT_TRUE(memory_cache_->ReadFully(0xa010, buffer.data(), kMaxCachedSize));
+  ASSERT_EQ(std::vector<uint8_t>(kMaxCachedSize, 0x50), buffer);
+
+  // Verify the cached data is not used.
+  memory_->SetMemoryBlock(0xa000, 3000, 0xff);
+  ASSERT_TRUE(memory_cache_->ReadFully(0xa010, buffer.data(), kMaxCachedSize));
+  ASSERT_EQ(std::vector<uint8_t>(kMaxCachedSize, 0xff), buffer);
+}
+
+TEST_F(MemoryCacheTest, read_for_cache_fail_cross) {
+  std::vector<uint8_t> expect(16, 0xde);
+  expect.resize(32, 0x50);
+
+  std::vector<uint8_t> buffer(32);
+  ASSERT_TRUE(memory_cache_->ReadFully(0x9ff0, buffer.data(), 32));
+  ASSERT_EQ(expect, buffer);
+
+  // Verify the cached data is not used for the second half but for the first.
+  memory_->SetMemoryBlock(0xa000, 3000, 0xff);
+  ASSERT_TRUE(memory_cache_->ReadFully(0x9ff0, buffer.data(), 32));
+  expect.resize(16);
+  expect.resize(32, 0xff);
+  ASSERT_EQ(expect, buffer);
+}
+
+}  // namespace unwindstack
diff --git a/libunwindstack/tools/unwind_info.cpp b/libunwindstack/tools/unwind_info.cpp
index aebeb95..3f2dfb0 100644
--- a/libunwindstack/tools/unwind_info.cpp
+++ b/libunwindstack/tools/unwind_info.cpp
@@ -123,6 +123,15 @@
     printf("Soname: %s\n", soname.c_str());
   }
 
+  std::string build_id;
+  if (elf.GetBuildID(&build_id)) {
+    printf("Build ID: ");
+    for (size_t i = 0; i < build_id.size(); ++i) {
+      printf("%02hhx", build_id[i]);
+    }
+    printf("\n");
+  }
+
   ElfInterface* interface = elf.interface();
   if (elf.machine_type() == EM_ARM) {
     DumpArm(&elf, reinterpret_cast<ElfInterfaceArm*>(interface));
diff --git a/libziparchive/Android.bp b/libziparchive/Android.bp
index 2095189..9538bba 100644
--- a/libziparchive/Android.bp
+++ b/libziparchive/Android.bp
@@ -125,6 +125,7 @@
             enabled: true,
         },
     },
+    test_suites: ["device-tests"],
 }
 
 // Performance benchmarks.
diff --git a/logd/LogAudit.cpp b/logd/LogAudit.cpp
index fc8c960..18d5287 100644
--- a/logd/LogAudit.cpp
+++ b/logd/LogAudit.cpp
@@ -165,9 +165,14 @@
         bug_num->assign("");
     }
 
+    // Ensure the uid name is not null before passing it to the bug string.
     if (uid >= AID_APP_START && uid <= AID_APP_END) {
-        bug_num->append(" app=");
-        bug_num->append(android::uidToName(uid));
+        char* uidname = android::uidToName(uid);
+        if (uidname) {
+            bug_num->append(" app=");
+            bug_num->append(uidname);
+            free(uidname);
+        }
     }
 }
 
diff --git a/property_service/libpropertyinfoparser/Android.bp b/property_service/libpropertyinfoparser/Android.bp
index 70f6faa..6637deb 100644
--- a/property_service/libpropertyinfoparser/Android.bp
+++ b/property_service/libpropertyinfoparser/Android.bp
@@ -12,5 +12,6 @@
         "-Werror",
     ],
     stl: "none",
+    system_shared_libs: [],
     export_include_dirs: ["include"],
 }
diff --git a/rootdir/Android.mk b/rootdir/Android.mk
index aad00ad..f88f6b9 100644
--- a/rootdir/Android.mk
+++ b/rootdir/Android.mk
@@ -9,6 +9,10 @@
 LOCAL_MODULE_CLASS := ETC
 LOCAL_MODULE_PATH := $(TARGET_ROOT_OUT)
 
+# The init symlink must be a post install command of a file that is to TARGET_ROOT_OUT.
+# Since init.rc is required for init and satisfies that requirement, we hijack it to create the symlink.
+LOCAL_POST_INSTALL_CMD := ln -sf /system/bin/init $(TARGET_ROOT_OUT)/init
+
 include $(BUILD_PREBUILT)
 
 #######################################
diff --git a/rootdir/etc/ld.config.legacy.txt b/rootdir/etc/ld.config.legacy.txt
index ca6aafe..461184a 100644
--- a/rootdir/etc/ld.config.legacy.txt
+++ b/rootdir/etc/ld.config.legacy.txt
@@ -6,35 +6,40 @@
 
 # All binaries gets the same configuration 'legacy'
 dir.legacy = /system
+dir.legacy = /product
 dir.legacy = /vendor
 dir.legacy = /odm
 dir.legacy = /sbin
 
-# Except for /postinstall, where only /system is searched
+# Except for /postinstall, where only /system and /product are searched
 dir.postinstall = /postinstall
 
 [legacy]
 namespace.default.isolated = false
 
 namespace.default.search.paths  = /system/${LIB}
+namespace.default.search.paths += /product/${LIB}
 namespace.default.search.paths += /vendor/${LIB}
 namespace.default.search.paths += /odm/${LIB}
 
 namespace.default.asan.search.paths  = /data/asan/system/${LIB}
 namespace.default.asan.search.paths +=           /system/${LIB}
-namespace.default.asan.search.paths += /data/asan/odm/${LIB}
-namespace.default.asan.search.paths +=           /odm/${LIB}
+namespace.default.asan.search.paths += /data/asan/product/${LIB}
+namespace.default.asan.search.paths +=           /product/${LIB}
 namespace.default.asan.search.paths += /data/asan/vendor/${LIB}
 namespace.default.asan.search.paths +=           /vendor/${LIB}
+namespace.default.asan.search.paths += /data/asan/odm/${LIB}
+namespace.default.asan.search.paths +=           /odm/${LIB}
 
 ###############################################################################
 # Namespace config for binaries under /postinstall.
 # Only one default namespace is defined and it has no directories other than
-# /system/lib in the search paths. This is because linker calls realpath on the
-# search paths and this causes selinux denial if the paths (/vendor, /odm) are
-# not allowed to the poinstall binaries. There is no reason to allow the
-# binaries to access the paths.
+# /system/lib and /product/lib in the search paths. This is because linker
+# calls realpath on the search paths and this causes selinux denial if the
+# paths (/vendor, /odm) are not allowed to the poinstall binaries.
+# There is no reason to allow the binaries to access the paths.
 ###############################################################################
 [postinstall]
 namespace.default.isolated = false
-namespace.default.search.paths = /system/${LIB}
+namespace.default.search.paths  = /system/${LIB}
+namespace.default.search.paths += /product/${LIB}
diff --git a/rootdir/init.environ.rc.in b/rootdir/init.environ.rc.in
index 4576776..d10f7c1 100644
--- a/rootdir/init.environ.rc.in
+++ b/rootdir/init.environ.rc.in
@@ -5,6 +5,7 @@
     export ANDROID_ASSETS /system/app
     export ANDROID_DATA /data
     export ANDROID_STORAGE /storage
+    export ANDROID_RUNTIME_ROOT /apex/com.android.runtime
     export EXTERNAL_STORAGE /sdcard
     export ASEC_MOUNTPOINT /mnt/asec
     export BOOTCLASSPATH %BOOTCLASSPATH%
diff --git a/rootdir/ueventd.rc b/rootdir/ueventd.rc
index 2f85dec..d90a1ce 100644
--- a/rootdir/ueventd.rc
+++ b/rootdir/ueventd.rc
@@ -1,7 +1,5 @@
 firmware_directories /etc/firmware/ /odm/firmware/ /vendor/firmware/ /firmware/image/
-
-subsystem adf
-    devname uevent_devname
+uevent_socket_rcvbuf_size 16M
 
 subsystem graphics
     devname uevent_devpath
@@ -11,26 +9,10 @@
     devname uevent_devpath
     dirname /dev/dri
 
-subsystem oncrpc
-    devname uevent_devpath
-    dirname /dev/oncrpc
-
-subsystem adsp
-    devname uevent_devpath
-    dirname /dev/adsp
-
-subsystem msm_camera
-    devname uevent_devpath
-    dirname /dev/msm_camera
-
 subsystem input
     devname uevent_devpath
     dirname /dev/input
 
-subsystem mtd
-    devname uevent_devpath
-    dirname /dev/mtd
-
 subsystem sound
     devname uevent_devpath
     dirname /dev/snd
@@ -58,73 +40,25 @@
 
 /dev/pmsg0                0222   root       log
 
-# the msm hw3d client device node is world writable/readable.
-/dev/msm_hw3dc            0666   root       root
-
-# gpu driver for adreno200 is globally accessible
-/dev/kgsl                 0666   root       root
-
 # kms driver for drm based gpu
 /dev/dri/*                0666   root       graphics
 
 # these should not be world writable
 /dev/diag                 0660   radio      radio
-/dev/diag_arm9            0660   radio      radio
 /dev/ttyMSM0              0600   bluetooth  bluetooth
 /dev/uhid                 0660   uhid       uhid
-/dev/uinput               0660   system     bluetooth
-/dev/alarm                0664   system     radio
+/dev/uinput               0660   uhid       uhid
 /dev/rtc0                 0640   system     system
 /dev/tty0                 0660   root       system
 /dev/graphics/*           0660   root       graphics
-/dev/msm_hw3dm            0660   system     graphics
 /dev/input/*              0660   root       input
 /dev/v4l-touch*           0660   root       input
-/dev/eac                  0660   root       audio
-/dev/cam                  0660   root       camera
-/dev/pmem                 0660   system     graphics
-/dev/pmem_adsp*           0660   system     audio
-/dev/pmem_camera*         0660   system     camera
-/dev/oncrpc/*             0660   root       system
-/dev/adsp/*               0660   system     audio
 /dev/snd/*                0660   system     audio
-/dev/mt9t013              0660   system     system
-/dev/msm_camera/*         0660   system     system
-/dev/akm8976_daemon       0640   compass    system
-/dev/akm8976_aot          0640   compass    system
-/dev/akm8973_daemon       0640   compass    system
-/dev/akm8973_aot          0640   compass    system
-/dev/bma150               0640   compass    system
-/dev/cm3602               0640   compass    system
-/dev/akm8976_pffd         0640   compass    system
-/dev/lightsensor          0640   system     system
-/dev/msm_pcm_out*         0660   system     audio
-/dev/msm_pcm_in*          0660   system     audio
-/dev/msm_pcm_ctl*         0660   system     audio
-/dev/msm_snd*             0660   system     audio
 /dev/msm_mp3*             0660   system     audio
-/dev/audience_a1026*      0660   system     audio
-/dev/tpa2018d1*           0660   system     audio
-/dev/msm_audpre           0660   system     audio
-/dev/msm_audio_ctl        0660   system     audio
-/dev/htc-acoustic         0660   system     audio
-/dev/vdec                 0660   system     audio
-/dev/q6venc               0660   system     audio
-/dev/snd/dsp              0660   system     audio
-/dev/snd/dsp1             0660   system     audio
-/dev/snd/mixer            0660   system     audio
-/dev/smd0                 0640   radio      radio
-/dev/qmi                  0640   radio      radio
-/dev/qmi0                 0640   radio      radio
-/dev/qmi1                 0640   radio      radio
-/dev/qmi2                 0640   radio      radio
-/dev/bus/usb/*            0660   root       usb
-/dev/mtp_usb              0660   root       mtp
 /dev/usb_accessory        0660   root       usb
 /dev/tun                  0660   system     vpn
 
 # CDMA radio interface MUX
-/dev/ts0710mux*           0640   radio      radio
 /dev/ppp                  0660   radio      vpn
 
 # sysfs properties
@@ -134,6 +68,3 @@
 /sys/devices/virtual/usb_composite/*   enable      0664  root   system
 /sys/devices/system/cpu/cpu*   cpufreq/scaling_max_freq   0664  system system
 /sys/devices/system/cpu/cpu*   cpufreq/scaling_min_freq   0664  system system
-
-# DVB API device nodes
-/dev/dvb*                 0660   root       system
diff --git a/shell_and_utilities/README.md b/shell_and_utilities/README.md
index d8cf867..ffda3a5 100644
--- a/shell_and_utilities/README.md
+++ b/shell_and_utilities/README.md
@@ -1,5 +1,4 @@
-Android's shell and utilities
-=============================
+# Android's shell and utilities
 
 Since IceCreamSandwich Android has used
 [mksh](https://www.mirbsd.org/mksh.htm) as its shell. Before then it used
@@ -34,8 +33,7 @@
 full list for a release by running `toybox` directly.
 
 
-Android 2.3 (Gingerbread)
--------------------------
+## Android 2.3 (Gingerbread)
 
 BSD: cat dd newfs\_msdos
 
@@ -46,8 +44,7 @@
 umount uptime vmstat watchprops wipe
 
 
-Android 4.0 (IceCreamSandwich)
-------------------------------
+## Android 4.0 (IceCreamSandwich)
 
 BSD: cat dd newfs\_msdos
 
@@ -58,8 +55,7 @@
 touch umount uptime vmstat watchprops wipe
 
 
-Android 4.1-4.3 (JellyBean)
----------------------------
+## Android 4.1-4.3 (JellyBean)
 
 BSD: cat cp dd du grep newfs\_msdos
 
@@ -71,8 +67,7 @@
 sync top touch umount uptime vmstat watchprops wipe
 
 
-Android 4.4 (KitKat)
---------------------
+## Android 4.4 (KitKat)
 
 BSD: cat cp dd du grep newfs\_msdos
 
@@ -84,8 +79,7 @@
 stop swapoff swapon sync top touch umount uptime vmstat watchprops wipe
 
 
-Android 5.0 (Lollipop)
-----------------------
+## Android 5.0 (Lollipop)
 
 BSD: cat chown cp dd du grep kill ln mv printenv rm rmdir sleep sync
 
@@ -97,8 +91,7 @@
 top touch umount uptime vmstat watchprops wipe
 
 
-Android 6.0 (Marshmallow)
--------------------------
+## Android 6.0 (Marshmallow)
 
 BSD: dd du grep
 
@@ -118,8 +111,7 @@
 vmstat wc which whoami xargs yes
 
 
-Android 7.0 (Nougat)
---------------------
+## Android 7.0 (Nougat)
 
 BSD: dd grep
 
@@ -140,8 +132,7 @@
 uptime usleep vmstat wc which whoami xargs xxd yes
 
 
-Android 8.0 (Oreo)
-------------------
+## Android 8.0 (Oreo)
 
 BSD: dd grep
 
@@ -164,8 +155,8 @@
 tty ulimit umount uname uniq unix2dos uptime usleep uudecode uuencode
 vmstat wc which whoami xargs xxd yes zcat
 
-Android P
----------
+
+## Android 9.0 (Pie)
 
 BSD: dd grep
 
@@ -190,8 +181,8 @@
 umount uname uniq unix2dos uptime usleep uudecode uuencode vmstat wc
 which whoami xargs xxd yes zcat
 
-Android Q
----------
+
+## Android Q
 
 BSD: grep fsck\_msdos newfs\_msdos
 
@@ -201,17 +192,22 @@
 
 toolbox: getevent getprop
 
-toybox: acpi base64 basename blockdev cal cat chcon chgrp chmod chown
-chroot chrt cksum clear cmp comm cp cpio cut date dd df diff dirname
-dmesg dos2unix du echo env expand expr fallocate false file find flock
-fmt free getenforce groups gunzip gzip head hostname hwclock id ifconfig
-inotifyd insmod ionice iorenice kill killall ln load\_policy log logname
-losetup ls lsmod lsof lspci lsusb md5sum microcom mkdir mkfifo mknod
-mkswap mktemp modinfo modprobe more mount mountpoint mv nc netcat netstat
-nice nl nohup nsenter od paste patch pgrep pidof pkill pmap printenv
-printf ps pwd readlink realpath renice restorecon rm rmdir rmmod runcon
-sed sendevent seq setenforce setprop setsid sha1sum sha224sum sha256sum
-sha384sum sha512sum sleep sort split start stat stop strings stty swapoff
-swapon sync sysctl tac tail tar taskset tee time timeout top touch tr
-true truncate tty ulimit umount uname uniq unix2dos unshare uptime usleep
-uudecode uuencode vmstat wc which whoami xargs xxd yes zcat
+toybox: acpi base64 basename bc blkid blockdev cal cat chattr chcon chgrp
+chmod chown chroot chrt cksum clear cmp comm cp cpio cut date dd df
+diff dirname dmesg dos2unix du echo egrep env expand expr fallocate
+false fgrep file find flock fmt free freeramdisk fsfreeze getconf
+getenforce getfattr grep groups gunzip gzip head help hostname hwclock
+i2cdetect i2cdump i2cget i2cset iconv id ifconfig inotifyd insmod
+install ionice iorenice iotop kill killall ln load\_policy log logname
+losetup ls lsattr lsmod lsof lspci lsusb makedevs md5sum microcom
+mkdir mkfifo mknod mkswap mktemp modinfo modprobe more mount mountpoint
+mv nbd-client nc netcat netstat nice nl nohup nproc nsenter od partprobe
+paste patch pgrep pidof ping ping6 pivot\_root pkill pmap printenv
+printf prlimit ps pwd pwdx readlink realpath renice restorecon rev
+rfkill rm rmdir rmmod runcon sed sendevent seq setenforce setfattr
+setprop setsid sha1sum sha224sum sha256sum sha384sum sha512sum sleep
+sort split start stat stop strings stty swapoff swapon sync sysctl
+tac tail tar taskset tee time timeout top touch tr traceroute traceroute6
+true truncate tty tunctl ulimit umount uname uniq unix2dos unlink
+unshare uptime usleep uudecode uuencode uuidgen vconfig vmstat watch
+wc which whoami xargs xxd yes zcat