diff --git a/adb/adb_io.cpp b/adb/adb_io.cpp
index 6cc274b..e6fefda 100644
--- a/adb/adb_io.cpp
+++ b/adb/adb_io.cpp
@@ -38,7 +38,8 @@
 
     // The cost of sending two strings outweighs the cost of formatting.
     // "adb sync" performance is affected by this.
-    return WriteFdFmt(fd, "%04x%.*s", length, length, s.c_str());
+    auto str = android::base::StringPrintf("%04x", length).append(s);
+    return WriteFdExactly(fd, str);
 }
 
 bool ReadProtocolString(int fd, std::string* s, std::string* error) {
diff --git a/adb/client/adb_install.cpp b/adb/client/adb_install.cpp
index 079a975..054cbac 100644
--- a/adb/client/adb_install.cpp
+++ b/adb/client/adb_install.cpp
@@ -331,11 +331,6 @@
         error_exit("Attempting to use streaming install on unsupported device");
     }
 
-    if (use_fastdeploy == true && is_reinstall == false) {
-        printf("Fast Deploy is only available with -r.\n");
-        use_fastdeploy = false;
-    }
-
     if (use_fastdeploy == true && get_device_api_level() < kFastDeployMinApi) {
         printf("Fast Deploy is only compatible with devices of API version %d or higher, "
                "ignoring.\n",
@@ -350,10 +345,17 @@
             passthrough_argv.push_back(argv[i]);
         }
     }
+    if (passthrough_argv.size() < 2) {
+        error_exit("install requires an apk argument");
+    }
 
     if (use_fastdeploy == true) {
         fastdeploy_set_local_agent(use_localagent);
         update_agent(agent_update_strategy);
+
+        // The last argument must be the APK file
+        const char* file = passthrough_argv.back();
+        use_fastdeploy = find_package(file);
     }
 
     switch (installMode) {
diff --git a/adb/client/commandline.cpp b/adb/client/commandline.cpp
index c8e834e..8676214 100644
--- a/adb/client/commandline.cpp
+++ b/adb/client/commandline.cpp
@@ -154,8 +154,8 @@
         "     --instant: cause the app to be installed as an ephemeral install app\n"
         "     --no-streaming: always push APK to device and invoke Package Manager as separate steps\n"
         "     --streaming: force streaming APK directly into Package Manager\n"
-        "     --fastdeploy: use fast deploy (only valid with -r)\n"
-        "     --no-fastdeploy: prevent use of fast deploy (only valid with -r)\n"
+        "     --fastdeploy: use fast deploy\n"
+        "     --no-fastdeploy: prevent use of fast deploy\n"
         "     --force-agent: force update of deployment agent when using fast deploy\n"
         "     --date-check-agent: update deployment agent when local version is newer and using fast deploy\n"
         "     --version-check-agent: update deployment agent when local version has different version code and using fast deploy\n"
diff --git a/adb/client/fastdeploy.cpp b/adb/client/fastdeploy.cpp
index e82f15a..f4e8664 100644
--- a/adb/client/fastdeploy.cpp
+++ b/adb/client/fastdeploy.cpp
@@ -16,6 +16,7 @@
 
 #include "fastdeploy.h"
 
+#include <string.h>
 #include <algorithm>
 #include <array>
 #include <memory>
@@ -31,7 +32,7 @@
 
 #include "adb_utils.h"
 
-static constexpr long kRequiredAgentVersion = 0x00000001;
+static constexpr long kRequiredAgentVersion = 0x00000002;
 
 static constexpr const char* kDeviceAgentPath = "/data/local/tmp/";
 
@@ -313,9 +314,16 @@
     std::vector<unsigned char> applyErrorBuffer;
     std::string argsString;
 
+    bool rSwitchPresent = false;
     for (int i = 0; i < argc; i++) {
         argsString.append(argv[i]);
         argsString.append(" ");
+        if (!strcmp(argv[i], "-r")) {
+            rSwitchPresent = true;
+        }
+    }
+    if (!rSwitchPresent) {
+        argsString.append("-r");
     }
 
     std::string applyPatchCommand =
@@ -326,3 +334,9 @@
         error_exit("Executing %s returned %d", applyPatchCommand.c_str(), returnCode);
     }
 }
+
+bool find_package(const char* apkPath) {
+    const std::string findCommand =
+            "/data/local/tmp/deployagent find " + get_packagename_from_apk(apkPath);
+    return !send_shell_command(findCommand);
+}
diff --git a/adb/client/fastdeploy.h b/adb/client/fastdeploy.h
index a6b10d3..7b7f2ec 100644
--- a/adb/client/fastdeploy.h
+++ b/adb/client/fastdeploy.h
@@ -32,3 +32,4 @@
 void apply_patch_on_device(const char* apkPath, const char* patchPath, const char* outputPath);
 void install_patch(const char* apkPath, const char* patchPath, int argc, const char** argv);
 std::string get_patch_path(const char* apkPath);
+bool find_package(const char* apkPath);
diff --git a/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java b/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
index 17845e2..2d3b135 100644
--- a/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
+++ b/adb/fastdeploy/deployagent/src/com/android/fastdeploy/DeployAgent.java
@@ -35,7 +35,7 @@
 
 public final class DeployAgent {
     private static final int BUFFER_SIZE = 128 * 1024;
-    private static final int AGENT_VERSION = 0x00000001;
+    private static final int AGENT_VERSION = 0x00000002;
 
     public static void main(String[] args) {
         int exitCode = 0;
@@ -53,6 +53,15 @@
 
                 String packageName = args[1];
                 extractMetaData(packageName);
+            } else if (commandString.equals("find")) {
+                if (args.length != 2) {
+                    showUsage(1);
+                }
+
+                String packageName = args[1];
+                if (getFilenameFromPackageName(packageName) == null) {
+                    exitCode = 3;
+                }
             } else if (commandString.equals("apply")) {
                 if (args.length < 4) {
                     showUsage(1);
@@ -112,6 +121,7 @@
             "usage: deployagent <command> [<args>]\n\n" +
             "commands:\n" +
             "version                             get the version\n" +
+            "find PKGNAME                        return zero if package found, else non-zero\n" +
             "extract PKGNAME                     extract an installed package's metadata\n" +
             "apply PKGNAME PATCHFILE [-o|-pm]    apply a patch from PATCHFILE (- for stdin) to an installed package\n" +
             " -o <FILE> directs output to FILE, default or - for stdout\n" +
@@ -134,7 +144,7 @@
         return null;
     }
 
-    private static File getFileFromPackageName(String packageName) throws IOException {
+    private static String getFilenameFromPackageName(String packageName) throws IOException {
         StringBuilder commandBuilder = new StringBuilder();
         commandBuilder.append("pm list packages -f " + packageName);
 
@@ -153,10 +163,19 @@
                 int equalsIndex = line.lastIndexOf(packageSuffix);
                 String fileName =
                     line.substring(packageIndex + packagePrefix.length(), equalsIndex);
-                return new File(fileName);
+                return fileName;
             }
         }
-        throw new IOException("package not found");
+        return null;
+    }
+
+    private static File getFileFromPackageName(String packageName) throws IOException {
+        String filename = getFilenameFromPackageName(packageName);
+        if (filename == null) {
+            // Should not happen (function is only called when we know the package exists)
+            throw new IOException("package not found");
+        }
+        return new File(filename);
     }
 
     private static void extractMetaData(String packageName) throws IOException {
diff --git a/base/Android.bp b/base/Android.bp
index 741664b..b0181aa 100644
--- a/base/Android.bp
+++ b/base/Android.bp
@@ -20,6 +20,7 @@
         "-Wall",
         "-Werror",
         "-Wextra",
+        "-D_FILE_OFFSET_BITS=64",
     ],
 }
 
diff --git a/debuggerd/Android.bp b/debuggerd/Android.bp
index d9fae52..5167481 100644
--- a/debuggerd/Android.bp
+++ b/debuggerd/Android.bp
@@ -116,14 +116,21 @@
         "libdebuggerd",
         "libbacktrace",
         "libunwindstack",
-        "libdexfile",
+        "libdexfile",  // libunwindstack dependency
+        "libdexfile_external",  // libunwindstack dependency
+        "libdexfile_support",  // libunwindstack dependency
         "liblzma",
         "libcutils",
     ],
     target: {
         recovery: {
             cflags: ["-DNO_LIBDEXFILE_SUPPORT"],
-            exclude_static_libs: ["libdexfile"],
+            exclude_static_libs: [
+                "libartbase",
+                "libdexfile",
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
         },
     },
 
@@ -170,12 +177,22 @@
 
     static_libs: [
         "libbacktrace",
+        "libdexfile_external",  // libunwindstack dependency
+        "libdexfile_support",  // libunwindstack dependency
         "libunwindstack",
         "liblzma",
         "libbase",
         "libcutils",
         "liblog",
     ],
+    target: {
+        recovery: {
+            exclude_static_libs: [
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
+        },
+    },
 }
 
 cc_test {
@@ -216,6 +233,8 @@
 
     static_libs: [
         "libdebuggerd",
+        "libdexfile_external",  // libunwindstack dependency
+        "libdexfile_support",  // libunwindstack dependency
         "libunwindstack",
     ],
 
diff --git a/debuggerd/libdebuggerd/test/tombstone_test.cpp b/debuggerd/libdebuggerd/test/tombstone_test.cpp
index 421ce43..d24c887 100644
--- a/debuggerd/libdebuggerd/test/tombstone_test.cpp
+++ b/debuggerd/libdebuggerd/test/tombstone_test.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <stdlib.h>
+#include <time.h>
 
 #include <memory>
 #include <string>
@@ -494,3 +495,10 @@
   expected += android::base::StringPrintf("ABI: '%s'\n", ABI_STRING);
   ASSERT_STREQ(expected.c_str(), amfd_data_.c_str());
 }
+
+TEST_F(TombstoneTest, dump_timestamp) {
+  setenv("TZ", "UTC", 1);
+  tzset();
+  dump_timestamp(&log_, 0);
+  ASSERT_STREQ("Timestamp: 1970-01-01 00:00:00+0000\n", amfd_data_.c_str());
+}
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 1179263..b20014f 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -78,6 +78,15 @@
   _LOG(log, logtype::HEADER, "ABI: '%s'\n", ABI_STRING);
 }
 
+static void dump_timestamp(log_t* log, time_t time) {
+  struct tm tm;
+  localtime_r(&time, &tm);
+
+  char buf[strlen("1970-01-01 00:00:00+0830") + 1];
+  strftime(buf, sizeof(buf), "%F %T%z", &tm);
+  _LOG(log, logtype::HEADER, "Timestamp: %s\n", buf);
+}
+
 static void dump_probable_cause(log_t* log, const siginfo_t* si, BacktraceMap* map) {
   std::string cause;
   if (si->si_signo == SIGSEGV && si->si_code == SEGV_MAPERR) {
@@ -654,6 +663,7 @@
 
   _LOG(&log, logtype::HEADER, "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
   dump_header_info(&log);
+  dump_timestamp(&log, time(nullptr));
 
   auto it = threads.find(target_thread);
   if (it == threads.end()) {
diff --git a/fastboot/device/commands.cpp b/fastboot/device/commands.cpp
index 71d2a1d..e91598d 100644
--- a/fastboot/device/commands.cpp
+++ b/fastboot/device/commands.cpp
@@ -329,12 +329,14 @@
     MetadataBuilder* operator->() const { return builder_.get(); }
 
   private:
+    FastbootDevice* device_;
     std::string super_device_;
     uint32_t slot_number_;
     std::unique_ptr<MetadataBuilder> builder_;
 };
 
-PartitionBuilder::PartitionBuilder(FastbootDevice* device, const std::string& partition_name) {
+PartitionBuilder::PartitionBuilder(FastbootDevice* device, const std::string& partition_name)
+    : device_(device) {
     std::string slot_suffix = GetSuperSlotSuffix(device, partition_name);
     slot_number_ = SlotNumberForSlotSuffix(slot_suffix);
     auto super_device = FindPhysicalPartition(fs_mgr_get_super_partition_name(slot_number_));
@@ -350,7 +352,7 @@
     if (!metadata) {
         return false;
     }
-    return UpdateAllPartitionMetadata(super_device_, *metadata.get());
+    return UpdateAllPartitionMetadata(device_, super_device_, *metadata.get());
 }
 
 bool CreatePartitionHandler(FastbootDevice* device, const std::vector<std::string>& args) {
diff --git a/fastboot/device/flashing.cpp b/fastboot/device/flashing.cpp
index fbba631..f737405 100644
--- a/fastboot/device/flashing.cpp
+++ b/fastboot/device/flashing.cpp
@@ -143,6 +143,11 @@
         return device->WriteFail("Data is not a valid logical partition metadata image");
     }
 
+    if (!FindPhysicalPartition(super_name)) {
+        return device->WriteFail("Cannot find " + super_name +
+                                 ", build may be missing broken or missing boot_devices");
+    }
+
     // If we are unable to read the existing metadata, then the super partition
     // is corrupt. In this case we reflash the whole thing using the provided
     // image.
@@ -184,7 +189,7 @@
     }
 
     // Write the new table to every metadata slot.
-    if (!UpdateAllPartitionMetadata(super_name, *new_metadata.get())) {
+    if (!UpdateAllPartitionMetadata(device, super_name, *new_metadata.get())) {
         return device->WriteFail("Unable to write new partition table");
     }
     fs_mgr_overlayfs_teardown();
diff --git a/fastboot/device/utility.cpp b/fastboot/device/utility.cpp
index 2ae9ac5..2ebd57d 100644
--- a/fastboot/device/utility.cpp
+++ b/fastboot/device/utility.cpp
@@ -200,10 +200,16 @@
     return cmdline.find("androidboot.verifiedbootstate=orange") == std::string::npos;
 }
 
-bool UpdateAllPartitionMetadata(const std::string& super_name,
+bool UpdateAllPartitionMetadata(FastbootDevice* device, const std::string& super_name,
                                 const android::fs_mgr::LpMetadata& metadata) {
+    size_t num_slots = 1;
+    auto boot_control_hal = device->boot_control_hal();
+    if (boot_control_hal) {
+        num_slots = boot_control_hal->getNumberSlots();
+    }
+
     bool ok = true;
-    for (size_t i = 0; i < metadata.geometry.metadata_slot_count; i++) {
+    for (size_t i = 0; i < num_slots; i++) {
         ok &= UpdatePartitionTable(super_name, metadata, i);
     }
     return ok;
diff --git a/fastboot/device/utility.h b/fastboot/device/utility.h
index 4c6aa07..bfeeb74 100644
--- a/fastboot/device/utility.h
+++ b/fastboot/device/utility.h
@@ -68,5 +68,5 @@
 bool GetDeviceLockStatus();
 
 // Update all copies of metadata.
-bool UpdateAllPartitionMetadata(const std::string& super_name,
+bool UpdateAllPartitionMetadata(FastbootDevice* device, const std::string& super_name,
                                 const android::fs_mgr::LpMetadata& metadata);
diff --git a/fs_mgr/Android.bp b/fs_mgr/Android.bp
index ac138a3..824511e 100644
--- a/fs_mgr/Android.bp
+++ b/fs_mgr/Android.bp
@@ -40,6 +40,7 @@
         "fs_mgr_verity.cpp",
         "fs_mgr_dm_linear.cpp",
         "fs_mgr_overlayfs.cpp",
+        "fs_mgr_roots.cpp",
         "fs_mgr_vendor_overlay.cpp",
     ],
     shared_libs: [
diff --git a/fs_mgr/README.overlayfs.md b/fs_mgr/README.overlayfs.md
index fbb5f5d..960410c 100644
--- a/fs_mgr/README.overlayfs.md
+++ b/fs_mgr/README.overlayfs.md
@@ -83,18 +83,19 @@
 -------
 
 - Space used in the backing storage is on a file by file basis
-  and will require more space than if updated in place.
+  and will require more space than if updated in place.  As such
+  it is important to be mindful of any wasted space, for instance
+  **BOARD_<partition>IMAGE_PARTITION_RESERVED_SIZE** being defined
+  will have a negative impact on the overall right-sizing of images
+  and thus free dynamic partition space.
 - Kernel must have CONFIG_OVERLAY_FS=y and will need to be patched
   with "*overlayfs: override_creds=off option bypass creator_cred*"
   if higher than 4.6.
 - *adb enable-verity* will free up overlayfs and as a bonus the
   device will be reverted pristine to before any content was updated.
   Update engine does not take advantage of this, will perform a full OTA.
-- Update engine will not run if *fs_mgr_overlayfs_is_setup*() reports
-  true as adb remount overrides are incompatable with an OTA for
-  multiple reasons.
-  NB: This is not a problem for fastbootd or recovery as overrides are
-  disabled for those special boot scenarios.
+- Update engine may not run if *fs_mgr_overlayfs_is_setup*() reports
+  true as adb remount overrides are incompatable with an OTA resources.
 - For implementation simplicity on retrofit dynamic partition devices,
   take the whole alternate super (eg: if "*a*" slot, then the whole of
   "*system_b*").
diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 8757689..943fe10 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -615,7 +615,7 @@
 // Sets errno to match the 1st mount failure on failure.
 static bool mount_with_alternatives(const Fstab& fstab, int start_idx, int* end_idx,
                                     int* attempted_idx) {
-    int i;
+    unsigned long i;
     int mount_errno = 0;
     bool mounted = false;
 
@@ -1179,11 +1179,12 @@
 
 // wrapper to __mount() and expects a fully prepared fstab_rec,
 // unlike fs_mgr_do_mount which does more things with avb / verity etc.
-int fs_mgr_do_mount_one(const FstabEntry& entry) {
+int fs_mgr_do_mount_one(const FstabEntry& entry, const std::string& mount_point) {
     // Run fsck if needed
     prepare_fs_for_mount(entry.blk_device, entry);
 
-    int ret = __mount(entry.blk_device, entry.mount_point, entry);
+    int ret =
+            __mount(entry.blk_device, mount_point.empty() ? entry.mount_point : mount_point, entry);
     if (ret) {
       ret = (errno == EBUSY) ? FS_MGR_DOMNT_BUSY : FS_MGR_DOMNT_FAILED;
     }
diff --git a/fs_mgr/fs_mgr_boot_config.cpp b/fs_mgr/fs_mgr_boot_config.cpp
index 733ad55..abece4d 100644
--- a/fs_mgr/fs_mgr_boot_config.cpp
+++ b/fs_mgr/fs_mgr_boot_config.cpp
@@ -81,6 +81,9 @@
 bool fs_mgr_get_boot_config_from_kernel_cmdline(const std::string& key, std::string* out_val) {
     std::string cmdline;
     if (!android::base::ReadFileToString("/proc/cmdline", &cmdline)) return false;
+    if (!cmdline.empty() && cmdline.back() == '\n') {
+        cmdline.pop_back();
+    }
     return fs_mgr_get_boot_config_from_kernel(cmdline, key, out_val);
 }
 
diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index d3cd459..e0891eb 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -59,7 +59,7 @@
 
 struct flag_list {
     const char *name;
-    unsigned int flag;
+    uint64_t flag;
 };
 
 static struct flag_list mount_flags[] = {
@@ -116,6 +116,7 @@
         {"logical", MF_LOGICAL},
         {"checkpoint=block", MF_CHECKPOINT_BLK},
         {"checkpoint=fs", MF_CHECKPOINT_FS},
+        {"slotselect_other", MF_SLOTSELECT_OTHER},
         {0, 0},
 };
 
@@ -153,7 +154,7 @@
     return 0;
 }
 
-static const char* flag_to_encryption_mode(const struct flag_list* list, int flag) {
+static const char* flag_to_encryption_mode(const struct flag_list* list, uint64_t flag) {
     const struct flag_list *j;
 
     for (j = list; j->name; ++j) {
@@ -207,11 +208,9 @@
     return false;
 }
 
-static int parse_flags(char *flags, struct flag_list *fl,
-                       struct fs_mgr_flag_values *flag_vals,
-                       char *fs_options, int fs_options_len)
-{
-    int f = 0;
+static uint64_t parse_flags(char* flags, struct flag_list* fl, struct fs_mgr_flag_values* flag_vals,
+                            char* fs_options, int fs_options_len) {
+    uint64_t f = 0;
     int i;
     char *p;
     char *savep;
diff --git a/fs_mgr/fs_mgr_priv.h b/fs_mgr/fs_mgr_priv.h
index 072da97..7d1159b 100644
--- a/fs_mgr/fs_mgr_priv.h
+++ b/fs_mgr/fs_mgr_priv.h
@@ -120,6 +120,8 @@
 #define MF_CHECKPOINT_FS  0x40000000
 #define MF_FIRST_STAGE_MOUNT \
                           0x80000000
+#define MF_SLOTSELECT_OTHER  \
+                         0x100000000
 // clang-format on
 
 #define DM_BUF_SIZE 4096
diff --git a/fs_mgr/fs_mgr_roots.cpp b/fs_mgr/fs_mgr_roots.cpp
new file mode 100644
index 0000000..f44ff41
--- /dev/null
+++ b/fs_mgr/fs_mgr_roots.cpp
@@ -0,0 +1,195 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fs_mgr/roots.h"
+
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <string>
+
+#include "fs_mgr.h"
+#include "fs_mgr_dm_linear.h"
+#include "fs_mgr_priv.h"
+
+namespace android {
+namespace fs_mgr {
+
+static constexpr const char* kSystemRoot = "/system";
+
+static bool gDidMapLogicalPartitions = false;
+
+FstabEntry* GetEntryForPath(Fstab* fstab, const std::string& path) {
+    if (path.empty()) return nullptr;
+    std::string str(path);
+    while (true) {
+        auto it = std::find_if(fstab->begin(), fstab->end(),
+                               [&str](const auto& entry) { return entry.mount_point == str; });
+        if (it != fstab->end()) return &*it;
+        if (str == "/") break;
+        auto slash = str.find_last_of('/');
+        if (slash == std::string::npos) break;
+        if (slash == 0) {
+            str = "/";
+        } else {
+            str = str.substr(0, slash);
+        }
+    }
+    return nullptr;
+}
+
+enum class MountState {
+    ERROR = -1,
+    NOT_MOUNTED = 0,
+    MOUNTED = 1,
+};
+
+static MountState GetMountState(const std::string& mount_point) {
+    Fstab mounted_fstab;
+    if (!ReadFstabFromFile("/proc/mounts", &mounted_fstab)) {
+        LERROR << "Failed to scan mounted volumes";
+        return MountState::ERROR;
+    }
+
+    auto mv = std::find_if(
+            mounted_fstab.begin(), mounted_fstab.end(),
+            [&mount_point](const auto& entry) { return entry.mount_point == mount_point; });
+    if (mv != mounted_fstab.end()) {
+        return MountState::MOUNTED;
+    }
+    return MountState::NOT_MOUNTED;
+}
+
+bool EnsurePathMounted(Fstab* fstab, const std::string& path, const std::string& mount_pt) {
+    auto rec = GetEntryForPath(fstab, path);
+    if (rec == nullptr) {
+        LERROR << "unknown volume for path [" << path << "]";
+        return false;
+    }
+    if (rec->fs_type == "ramdisk") {
+        // The ramdisk is always mounted.
+        return true;
+    }
+
+    // If we can't acquire the block device for a logical partition, it likely
+    // was never created. In that case we try to create it.
+    if (rec->fs_mgr_flags.logical && !fs_mgr_update_logical_partition(rec)) {
+        if (gDidMapLogicalPartitions) {
+            LERROR << "Failed to find block device for partition";
+            return false;
+        }
+        std::string super_name = fs_mgr_get_super_partition_name();
+        if (!android::fs_mgr::CreateLogicalPartitions("/dev/block/by-name/" + super_name)) {
+            LERROR << "Failed to create logical partitions";
+            return false;
+        }
+        gDidMapLogicalPartitions = true;
+        if (!fs_mgr_update_logical_partition(rec)) {
+            LERROR << "Failed to find block device for partition";
+            return false;
+        }
+    }
+
+    auto mounted = GetMountState(rec->mount_point);
+    if (mounted == MountState::ERROR) {
+        return false;
+    }
+    if (mounted == MountState::MOUNTED) {
+        return true;
+    }
+
+    const std::string mount_point = mount_pt.empty() ? rec->mount_point : mount_pt;
+
+    static const std::vector<std::string> supported_fs{"ext4", "squashfs", "vfat", "f2fs"};
+    if (std::find(supported_fs.begin(), supported_fs.end(), rec->fs_type) == supported_fs.end()) {
+        LERROR << "unknown fs_type \"" << rec->fs_type << "\" for " << mount_point;
+        return false;
+    }
+
+    int result = fs_mgr_do_mount_one(*rec, mount_point);
+    if (result == -1 && rec->fs_mgr_flags.formattable) {
+        PERROR << "Failed to mount " << mount_point << "; formatting";
+        bool crypt_footer = rec->is_encryptable() && rec->key_loc == "footer";
+        if (fs_mgr_do_format(*rec, crypt_footer) != 0) {
+            PERROR << "Failed to format " << mount_point;
+            return false;
+        }
+        result = fs_mgr_do_mount_one(*rec, mount_point);
+    }
+
+    if (result == -1) {
+        PERROR << "Failed to mount " << mount_point;
+        return false;
+    }
+    return true;
+}
+
+bool EnsurePathUnmounted(Fstab* fstab, const std::string& path) {
+    auto rec = GetEntryForPath(fstab, path);
+    if (rec == nullptr) {
+        LERROR << "unknown volume for path [" << path << "]";
+        return false;
+    }
+    if (rec->fs_type == "ramdisk") {
+        // The ramdisk is always mounted; you can't unmount it.
+        return false;
+    }
+
+    Fstab mounted_fstab;
+    if (!ReadFstabFromFile("/proc/mounts", &mounted_fstab)) {
+        LERROR << "Failed to scan mounted volumes";
+        return false;
+    }
+
+    auto mounted = GetMountState(rec->mount_point);
+    if (mounted == MountState::ERROR) {
+        return false;
+    }
+    if (mounted == MountState::NOT_MOUNTED) {
+        return true;
+    }
+
+    int result = umount(rec->mount_point.c_str());
+    if (result == -1) {
+        PWARNING << "Failed to umount " << rec->mount_point;
+        return false;
+    }
+    return true;
+}
+
+std::string GetSystemRoot() {
+    Fstab fstab;
+    if (!ReadDefaultFstab(&fstab)) {
+        LERROR << "Failed to read default fstab";
+        return "";
+    }
+
+    auto it = std::find_if(fstab.begin(), fstab.end(),
+                           [](const auto& entry) { return entry.mount_point == kSystemRoot; });
+    if (it == fstab.end()) {
+        return "/";
+    }
+
+    return kSystemRoot;
+}
+
+bool LogicalPartitionsMapped() {
+    return gDidMapLogicalPartitions;
+}
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/fs_mgr_slotselect.cpp b/fs_mgr/fs_mgr_slotselect.cpp
index efc29bd..3cb718c 100644
--- a/fs_mgr/fs_mgr_slotselect.cpp
+++ b/fs_mgr/fs_mgr_slotselect.cpp
@@ -21,6 +21,19 @@
 #include "fs_mgr.h"
 #include "fs_mgr_priv.h"
 
+// https://source.android.com/devices/tech/ota/ab/ab_implement#partitions
+// All partitions that are A/B-ed should be named as follows (slots are always
+// named a, b, etc.): boot_a, boot_b, system_a, system_b, vendor_a, vendor_b.
+static std::string other_suffix(const std::string& slot_suffix) {
+    if (slot_suffix == "_a") {
+        return "_b";
+    }
+    if (slot_suffix == "_b") {
+        return "_a";
+    }
+    return "";
+}
+
 // Returns "_a" or "_b" based on androidboot.slot_suffix in kernel cmdline, or an empty string
 // if that parameter does not exist.
 std::string fs_mgr_get_slot_suffix() {
@@ -35,7 +48,7 @@
     std::string ab_suffix;
 
     for (auto& entry : *fstab) {
-        if (!entry.fs_mgr_flags.slot_select) {
+        if (!entry.fs_mgr_flags.slot_select && !entry.fs_mgr_flags.slot_select_other) {
             continue;
         }
 
@@ -45,8 +58,10 @@
             if (ab_suffix.empty()) return false;
         }
 
-        entry.blk_device = entry.blk_device + ab_suffix;
-        entry.logical_partition_name = entry.logical_partition_name + ab_suffix;
+        const auto& update_suffix =
+                entry.fs_mgr_flags.slot_select ? ab_suffix : other_suffix(ab_suffix);
+        entry.blk_device = entry.blk_device + update_suffix;
+        entry.logical_partition_name = entry.logical_partition_name + update_suffix;
     }
     return true;
 }
diff --git a/fs_mgr/include/fs_mgr.h b/fs_mgr/include/fs_mgr.h
index 814ba46..e87332f 100644
--- a/fs_mgr/include/fs_mgr.h
+++ b/fs_mgr/include/fs_mgr.h
@@ -69,7 +69,7 @@
 int fs_mgr_do_mount(fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point);
 int fs_mgr_do_mount(fstab* fstab, const char* n_name, char* n_blk_device, char* tmp_mount_point,
                     bool need_cp);
-int fs_mgr_do_mount_one(const FstabEntry& entry);
+int fs_mgr_do_mount_one(const FstabEntry& entry, const std::string& mount_point = "");
 int fs_mgr_do_mount_one(fstab_rec* rec);
 int fs_mgr_do_tmpfs_mount(const char *n_name);
 fstab_rec const* fs_mgr_get_crypt_entry(fstab const* fstab);
diff --git a/fs_mgr/include/fs_mgr/roots.h b/fs_mgr/include/fs_mgr/roots.h
new file mode 100644
index 0000000..65c59cf
--- /dev/null
+++ b/fs_mgr/include/fs_mgr/roots.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <string>
+
+#include <fs_mgr.h>
+
+namespace android {
+namespace fs_mgr {
+
+// Finds the volume specified by the given path. fs_mgr_get_entry_for_mount_point() does exact match
+// only, so it attempts the prefixes recursively (e.g. "/cache/recovery/last_log",
+// "/cache/recovery", "/cache", "/" for a given path of "/cache/recovery/last_log") and returns the
+// first match or nullptr.
+FstabEntry* GetEntryForPath(Fstab* fstab, const std::string& path);
+
+// Make sure that the volume 'path' is on is mounted.
+// * If 'mount_point' is nullptr, use mount point in fstab. Caller can call
+//   fs_mgr_ensure_path_unmounted() with the same 'path' argument to unmount.
+// * If 'mount_point' is not nullptr, the mount point is overridden. Caller can
+//   call umount(mount_point) to unmount.
+// Returns true on success (volume is mounted).
+bool EnsurePathMounted(Fstab* fstab, const std::string& path, const std::string& mount_point = "");
+
+// Make sure that the volume 'path' is on is unmounted.  Returns true on
+// success (volume is unmounted).
+bool EnsurePathUnmounted(Fstab* fstab, const std::string& path);
+
+// Return "/system" if it is in default fstab, otherwise "/".
+std::string GetSystemRoot();
+
+// Return true iff logical partitions are mapped when partitions are mounted via ensure_path_mounted
+// functions.
+bool LogicalPartitionsMapped();
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/include_fstab/fstab/fstab.h b/fs_mgr/include_fstab/fstab/fstab.h
index d9a5e0a..0997254 100644
--- a/fs_mgr/include_fstab/fstab/fstab.h
+++ b/fs_mgr/include_fstab/fstab/fstab.h
@@ -43,7 +43,7 @@
     char* fs_type;
     unsigned long flags;
     char* fs_options;
-    int fs_mgr_flags;
+    uint64_t fs_mgr_flags;
     char* key_loc;
     char* key_dir;
     char* verity_loc;
@@ -123,8 +123,9 @@
     // TODO: Remove this union once fstab_rec is deprecated. It only serves as a
     // convenient way to convert between fstab_rec::fs_mgr_flags and these bools.
     union {
-        int val;
+        uint64_t val;
         struct {
+            // bit 0
             bool wait : 1;
             bool check : 1;
             bool crypt : 1;
@@ -133,6 +134,8 @@
             bool length : 1;
             bool recovery_only : 1;
             bool swap_prio : 1;
+
+            // bit 8
             bool zram_size : 1;
             bool verify : 1;
             bool force_crypt : 1;
@@ -142,6 +145,8 @@
             bool file_encryption : 1;
             bool formattable : 1;
             bool slot_select : 1;
+
+            // bit 16
             bool force_fde_or_fbe : 1;
             bool late_mount : 1;
             bool no_fail : 1;
@@ -150,6 +155,8 @@
             bool reserved_size : 1;
             bool quota : 1;
             bool erase_blk_size : 1;
+
+            // bit 24
             bool logical_blk_size : 1;
             bool avb : 1;
             bool key_directory : 1;
@@ -158,6 +165,9 @@
             bool checkpoint_blk : 1;
             bool checkpoint_fs : 1;
             bool first_stage_mount : 1;
+
+            // bit 32
+            bool slot_select_other : 1;
         };
     } fs_mgr_flags;
 
diff --git a/fs_mgr/libdm/Android.bp b/fs_mgr/libdm/Android.bp
index 22af123..90bce51 100644
--- a/fs_mgr/libdm/Android.bp
+++ b/fs_mgr/libdm/Android.bp
@@ -20,10 +20,6 @@
     recovery_available: true,
 
     export_include_dirs: ["include"],
-    cflags: [
-        // TODO(b/110035986): Allows us to create a skeleton of required classes
-        "-Wno-unused-private-field",
-    ],
 
     srcs: [
         "dm_table.cpp",
diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index aaee1a7..9e211e3 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -92,7 +92,7 @@
 
 Returns: true if device is (likely) a debug build" ]
 isDebuggable() {
-  if inAdb && [ 1 -ne `get_property ro.debuggable` ]; then
+  if inAdb && [ 1 -ne "`get_property ro.debuggable`" ]; then
     false
   fi
 }
@@ -290,6 +290,11 @@
 fi
 inAdb || die "specified device not in adb mode"
 isDebuggable || die "device not a debug build"
+enforcing=true
+if ! adb_su getenforce </dev/null | grep 'Enforcing' >/dev/null; then
+  echo "${ORANGE}[  WARNING ]${NORMAL} device does not have sepolicy in enforcing mode"
+  enforcing=false
+fi
 
 # Do something
 
@@ -384,16 +389,16 @@
   die -t "${T}" "disable-verity"
 fi
 rebooted=false
-if [ X"${D}" != X"${H}" -a X"${D}" = X"${D##*using overlayfs}" ]; then
+if [ X"${D}" != X"${H}" ]; then
   echo "${H}"
   if [ X"${D}" != X"${D##*setup failed}" ]; then
     echo "${ORANGE}[  WARNING ]${NORMAL} overlayfs setup whined" >&2
   fi
   D=`adb_sh df -k </dev/null` &&
     H=`echo "${D}" | head -1` &&
-    D=`echo "${D}" | grep "^overlay "` &&
-    [ -n "${D}" ] &&
-    ( echo "${H}" && echo "${D}" ) &&
+    D=`echo "${D}" | grep "^overlay " || true` &&
+    [ -z "${D}" ] ||
+    ( echo "${H}" && echo "${D}" && false ) ||
     die -t ${T} "overlay takeover unexpected at this phase"
   echo "${GREEN}[     INFO ]${NORMAL} rebooting as requested" >&2
   L=`adb_logcat -b all -v nsec -t ${T} 2>&1`
@@ -421,12 +426,12 @@
   die -t "${T}" "setup for overlay"
 fi
 if [ X"${D}" != X"${D##*Successfully disabled verity}" ]; then
-  echo "${D}"
+  echo "${H}"
   D=`adb_sh df -k </dev/null` &&
     H=`echo "${D}" | head -1` &&
-    D=`echo "${D}" | grep "^overlay " | true` &&
-    [ -n "${D}" ] &&
-    ( echo "${H}" && echo "${D}" ) &&
+    D=`echo "${D}" | grep "^overlay " || true` &&
+    [ -z "${D}" ] ||
+    ( echo "${H}" && echo "${D}" && false ) ||
     ( [ -n "${L}" ] && echo "${L}" && false ) ||
     die -t "${T}" "overlay takeover unexpected"
   [ -n "${L}" ] && echo "${L}"
@@ -499,17 +504,17 @@
 
 # Check something
 
-echo "${GREEN}[ RUN      ]${NORMAL} push content to system and vendor" >&2
+echo "${GREEN}[ RUN      ]${NORMAL} push content to /system and /vendor" >&2
 
 A="Hello World! $(date)"
 echo "${A}" | adb_sh "cat - > /system/hello"
 echo "${A}" | adb_sh "cat - > /vendor/hello"
 B="`adb_cat /system/hello`" ||
   die "sytem hello"
-check_eq "${A}" "${B}" system before reboot
+check_eq "${A}" "${B}" /system before reboot
 B="`adb_cat /vendor/hello`" ||
   die "vendor hello"
-check_eq "${A}" "${B}" vendor before reboot
+check_eq "${A}" "${B}" /vendor before reboot
 
 echo "${GREEN}[ RUN      ]${NORMAL} reboot to confirm content persistent" >&2
 
@@ -532,16 +537,21 @@
 fi
 
 B="`adb_cat /system/hello`" ||
-  die "re-read system hello after reboot"
-check_eq "${A}" "${B}" system after reboot
+  die "re-read /system/hello after reboot"
+check_eq "${A}" "${B}" /system after reboot
+echo "${GREEN}[       OK ]${NORMAL} /system content remains after reboot" >&2
 # Only root can read vendor if sepolicy permissions are as expected
-B="`adb_cat /vendor/hello`" &&
-  die "re-read vendor hello after reboot w/o root"
-check_eq "cat: /vendor/hello: Permission denied" "${B}" vendor after reboot w/o root
+if ${enforcing}; then
+  B="`adb_cat /vendor/hello`" &&
+    die "re-read /vendor/hello after reboot w/o root"
+  check_eq "cat: /vendor/hello: Permission denied" "${B}" vendor after reboot w/o root
+  echo "${GREEN}[       OK ]${NORMAL} /vendor content correct MAC after reboot" >&2
+fi
 adb_root &&
   B="`adb_cat /vendor/hello`" ||
-  die "re-read vendor hello after reboot"
+  die "re-read /vendor/hello after reboot"
 check_eq "${A}" "${B}" vendor after reboot
+echo "${GREEN}[       OK ]${NORMAL} /vendor content remains after reboot" >&2
 
 echo "${GREEN}[ RUN      ]${NORMAL} flash vendor, confirm its content disappears" >&2
 
@@ -601,17 +611,17 @@
       echo "${H}" &&
       echo "${D}" &&
       echo "${D}" | grep "^overlay .* /system\$" >/dev/null ||
-      die  "overlay system takeover after flash vendor"
+      die  "overlay /system takeover after flash vendor"
     echo "${D}" | grep "^overlay .* /vendor\$" >/dev/null &&
-      die  "overlay minus vendor takeover after flash vendor"
+      die  "overlay supposed to be minus /vendor takeover after flash vendor"
   fi
   B="`adb_cat /system/hello`" ||
-    die "re-read system hello after flash vendor"
+    die "re-read /system/hello after flash vendor"
   check_eq "${A}" "${B}" system after flash vendor
   adb_root ||
     die "adb root"
   B="`adb_cat /vendor/hello`" &&
-    die "re-read vendor hello after flash vendor"
+    die "re-read /vendor/hello after flash vendor"
   check_eq "cat: /vendor/hello: No such file or directory" "${B}" vendor after flash vendor
 fi
 
@@ -623,10 +633,10 @@
   adb_sh rm /system/hello </dev/null ||
   die -t ${T} "cleanup hello"
 B="`adb_cat /system/hello`" &&
-  die "re-read system hello after rm"
+  die "re-read /system/hello after rm"
 check_eq "cat: /system/hello: No such file or directory" "${B}" after flash rm
 B="`adb_cat /vendor/hello`" &&
-  die "re-read vendor hello after rm"
+  die "re-read /vendor/hello after rm"
 check_eq "cat: /vendor/hello: No such file or directory" "${B}" after flash rm
 
 if [ -n "${scratch_partition}" ]; then
diff --git a/init/first_stage_mount.cpp b/init/first_stage_mount.cpp
index c96c381..b5ff658 100644
--- a/init/first_stage_mount.cpp
+++ b/init/first_stage_mount.cpp
@@ -42,6 +42,7 @@
 #include "uevent_listener.h"
 #include "util.h"
 
+using android::base::ReadFileToString;
 using android::base::Split;
 using android::base::Timer;
 using android::fs_mgr::AvbHandle;
@@ -73,6 +74,8 @@
     bool CreateLogicalPartitions();
     bool MountPartition(FstabEntry* fstab_entry);
     bool MountPartitions();
+    bool TrySwitchSystemAsRoot();
+    bool TrySkipMountingPartitions();
     bool IsDmLinearEnabled();
     bool GetDmLinearMetadataDevice();
     bool InitDmLinearBackingDevices(const android::fs_mgr::LpMetadata& metadata);
@@ -392,16 +395,21 @@
         return false;
     }
     if (fs_mgr_do_mount_one(*fstab_entry)) {
+        if (fstab_entry->fs_mgr_flags.formattable) {
+            PLOG(INFO) << "Failed to mount '" << fstab_entry->mount_point << "', "
+                       << "ignoring mount for formattable partition";
+            return true;
+        }
         PLOG(ERROR) << "Failed to mount '" << fstab_entry->mount_point << "'";
         return false;
     }
     return true;
 }
 
-bool FirstStageMount::MountPartitions() {
-    // If system is in the fstab then we're not a system-as-root device, and in
-    // this case, we mount system first then pivot to it.  From that point on,
-    // we are effectively identical to a system-as-root device.
+// If system is in the fstab then we're not a system-as-root device, and in
+// this case, we mount system first then pivot to it.  From that point on,
+// we are effectively identical to a system-as-root device.
+bool FirstStageMount::TrySwitchSystemAsRoot() {
     auto system_partition = std::find_if(fstab_.begin(), fstab_.end(), [](const auto& entry) {
         return entry.mount_point == "/system";
     });
@@ -416,6 +424,44 @@
         fstab_.erase(system_partition);
     }
 
+    return true;
+}
+
+// For GSI to skip mounting /product and /product_services, until there are
+// well-defined interfaces between them and /system. Otherwise, the GSI flashed
+// on /system might not be able to work with /product and /product_services.
+// When they're skipped here, /system/product and /system/product_services in
+// GSI will be used.
+bool FirstStageMount::TrySkipMountingPartitions() {
+    constexpr const char kSkipMountConfig[] = "/system/etc/init/config/skip_mount.cfg";
+
+    std::string skip_config;
+    if (!ReadFileToString(kSkipMountConfig, &skip_config)) {
+        return true;
+    }
+
+    for (const auto& skip_mount_point : Split(skip_config, "\n")) {
+        if (skip_mount_point.empty()) {
+            continue;
+        }
+        auto removing_entry =
+                std::find_if(fstab_.begin(), fstab_.end(), [&skip_mount_point](const auto& entry) {
+                    return entry.mount_point == skip_mount_point;
+                });
+        if (removing_entry != fstab_.end()) {
+            fstab_.erase(removing_entry);
+            LOG(INFO) << "Skip mounting partition: " << skip_mount_point;
+        }
+    }
+
+    return true;
+}
+
+bool FirstStageMount::MountPartitions() {
+    if (!TrySwitchSystemAsRoot()) return false;
+
+    if (!TrySkipMountingPartitions()) return false;
+
     for (auto& fstab_entry : fstab_) {
         if (!MountPartition(&fstab_entry) && !fstab_entry.fs_mgr_flags.no_fail) {
             return false;
diff --git a/init/selinux.cpp b/init/selinux.cpp
index 3a09096..04ca207 100644
--- a/init/selinux.cpp
+++ b/init/selinux.cpp
@@ -306,6 +306,11 @@
     }
     std::string mapping_file("/system/etc/selinux/mapping/" + vend_plat_vers + ".cil");
 
+    std::string product_policy_cil_file("/product/etc/selinux/product_sepolicy.cil");
+    if (access(product_policy_cil_file.c_str(), F_OK) == -1) {
+        product_policy_cil_file.clear();
+    }
+
     // vendor_sepolicy.cil and plat_pub_versioned.cil are the new design to replace
     // nonplat_sepolicy.cil.
     std::string plat_pub_versioned_cil_file("/vendor/etc/selinux/plat_pub_versioned.cil");
@@ -342,6 +347,9 @@
     };
     // clang-format on
 
+    if (!product_policy_cil_file.empty()) {
+        compile_args.push_back(product_policy_cil_file.c_str());
+    }
     if (!plat_pub_versioned_cil_file.empty()) {
         compile_args.push_back(plat_pub_versioned_cil_file.c_str());
     }
diff --git a/libappfuse/FuseBridgeLoop.cc b/libappfuse/FuseBridgeLoop.cc
index 8b0c53e..ac94e69 100644
--- a/libappfuse/FuseBridgeLoop.cc
+++ b/libappfuse/FuseBridgeLoop.cc
@@ -311,7 +311,7 @@
 };
 
 FuseBridgeLoop::FuseBridgeLoop() : opened_(true) {
-    base::unique_fd epoll_fd(epoll_create1(/* no flag */ 0));
+    base::unique_fd epoll_fd(epoll_create1(EPOLL_CLOEXEC));
     if (epoll_fd.get() == -1) {
         PLOG(ERROR) << "Failed to open FD for epoll";
         opened_ = false;
diff --git a/libbacktrace/BacktraceCurrent.cpp b/libbacktrace/BacktraceCurrent.cpp
index 39cb995..038b59e 100644
--- a/libbacktrace/BacktraceCurrent.cpp
+++ b/libbacktrace/BacktraceCurrent.cpp
@@ -76,7 +76,7 @@
     return UnwindFromContext(num_ignore_frames, ucontext);
   }
 
-  if (Tid() != android::base::GetThreadId()) {
+  if (Tid() != static_cast<pid_t>(android::base::GetThreadId())) {
     return UnwindThread(num_ignore_frames);
   }
 
diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index fe28eba..f5f9b2a 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -117,7 +117,7 @@
     back_frame->map.name = frame->map_name;
     back_frame->map.start = frame->map_start;
     back_frame->map.end = frame->map_end;
-    back_frame->map.offset = frame->map_offset;
+    back_frame->map.offset = frame->map_elf_start_offset;
     back_frame->map.load_bias = frame->map_load_bias;
     back_frame->map.flags = frame->map_flags;
   }
diff --git a/libcutils/include/private/android_filesystem_config.h b/libcutils/include/private/android_filesystem_config.h
index 68bf898..0723612 100644
--- a/libcutils/include/private/android_filesystem_config.h
+++ b/libcutils/include/private/android_filesystem_config.h
@@ -133,6 +133,7 @@
 #define AID_LLKD 1070            /* live lock daemon */
 #define AID_IORAPD 1071          /* input/output readahead and pin daemon */
 #define AID_GPU_SERVICE 1072     /* GPU service daemon */
+#define AID_NETWORK_STACK 1073   /* network stack service */
 /* Changes to this file must be made in AOSP, *not* in internal branches. */
 
 #define AID_SHELL 2000 /* adb and debug shell user */
diff --git a/libmeminfo/tools/Android.bp b/libmeminfo/tools/Android.bp
index 715d63d..1f93494 100644
--- a/libmeminfo/tools/Android.bp
+++ b/libmeminfo/tools/Android.bp
@@ -13,11 +13,24 @@
 // limitations under the License.
 
 cc_binary {
+    name: "librank2",
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+
+    srcs: ["librank.cpp"],
+    shared_libs: [
+        "libbase",
+        "libmeminfo",
+    ],
+}
+
+cc_binary {
     name: "procmem2",
     cflags: [
         "-Wall",
         "-Werror",
-        "-Wno-unused-parameter",
     ],
 
     srcs: ["procmem.cpp"],
@@ -32,7 +45,6 @@
     cflags: [
         "-Wall",
         "-Werror",
-        "-Wno-unused-parameter",
     ],
 
     srcs: ["procrank.cpp"],
diff --git a/libmeminfo/tools/librank.cpp b/libmeminfo/tools/librank.cpp
new file mode 100644
index 0000000..7668640
--- /dev/null
+++ b/libmeminfo/tools/librank.cpp
@@ -0,0 +1,350 @@
+/*
+ * 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 <error.h>
+#include <inttypes.h>
+#include <linux/kernel-page-flags.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <memory>
+#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>
+
+using ::android::meminfo::MemUsage;
+using ::android::meminfo::ProcMemInfo;
+using ::android::meminfo::Vma;
+
+[[noreturn]] static void usage(const char* myname, int exit_status) {
+    fprintf(stderr,
+            "Usage: %s [ -P | -L ] [ -v | -r | -p | -u | -s | -h ]\n"
+            "\n"
+            "Sort options:\n"
+            "    -v  Sort processes by VSS.\n"
+            "    -r  Sort processes by RSS.\n"
+            "    -p  Sort processes by PSS.\n"
+            "    -u  Sort processes by USS.\n"
+            "    -s  Sort processes by swap.\n"
+            "        (Default sort order is PSS.)\n"
+            "    -a  Show all mappings, including stack, heap and anon.\n"
+            "    -P /path  Limit libraries displayed to those in path.\n"
+            "    -R  Reverse sort order (default is descending).\n"
+            "    -m [r][w][x] Only list pages that exactly match permissions\n"
+            "    -c  Only show cached (storage backed) pages\n"
+            "    -C  Only show non-cached (ram/swap backed) pages\n"
+            "    -k  Only show pages collapsed by KSM\n"
+            "    -h  Display this help screen.\n",
+            myname);
+    exit(exit_status);
+}
+
+static void add_mem_usage(MemUsage* to, const MemUsage& from) {
+    to->vss += from.vss;
+    to->rss += from.rss;
+    to->pss += from.pss;
+    to->uss += from.uss;
+
+    to->swap += from.swap;
+
+    to->private_clean += from.private_clean;
+    to->private_dirty += from.private_dirty;
+
+    to->shared_clean += from.shared_clean;
+    to->shared_dirty += from.shared_dirty;
+}
+
+struct ProcessRecord {
+  public:
+    ProcessRecord(pid_t pid) : pid_(-1), cmdline_("") {
+        std::string fname = ::android::base::StringPrintf("/proc/%d/cmdline", pid);
+        std::string cmdline;
+        if (!::android::base::ReadFileToString(fname, &cmdline)) {
+            fprintf(stderr, "Failed to read cmdline from: %s\n", fname.c_str());
+            return;
+        }
+        // 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_ = cmdline.c_str();
+        pid_ = pid;
+        usage_.clear();
+    }
+
+    ~ProcessRecord() = default;
+
+    bool valid() const { return pid_ != -1; }
+
+    // Getters
+    pid_t pid() const { return pid_; }
+    const std::string& cmdline() const { return cmdline_; }
+    const MemUsage& usage() const { return usage_; }
+
+    // Add to the usage
+    void AddUsage(const MemUsage& mem_usage) { add_mem_usage(&usage_, mem_usage); }
+
+  private:
+    pid_t pid_;
+    std::string cmdline_;
+    MemUsage usage_;
+};
+
+struct LibRecord {
+  public:
+    LibRecord(const std::string& name) : name_(name) {}
+    ~LibRecord() = default;
+
+    const std::string& name() const { return name_; }
+    const MemUsage& usage() const { return usage_; }
+    const std::vector<ProcessRecord>& processes() const { return procs_; }
+    uint64_t pss() const { return usage_.pss; }
+    void AddUsage(const ProcessRecord& proc, const MemUsage& mem_usage) {
+        auto process = std::find_if(procs_.begin(), procs_.end(),
+                                    [&](auto p) -> bool { return p.pid() == proc.pid(); });
+        if (process == procs_.end()) {
+            process = procs_.emplace(procs_.end(), proc.pid());
+        }
+        process->AddUsage(mem_usage);
+        add_mem_usage(&usage_, mem_usage);
+    }
+
+    void Sort(std::function<bool(const ProcessRecord&, const ProcessRecord&)>& sorter) {
+        std::sort(procs_.begin(), procs_.end(), sorter);
+    }
+
+  private:
+    std::string name_;
+    MemUsage usage_;
+    std::vector<ProcessRecord> procs_;
+};
+
+// List of every library / map
+static std::vector<LibRecord> g_libs;
+
+// List of library/map names that we don't want to show by default
+static const std::vector<std::string> g_blacklisted_libs = {"[heap]", "[stack]"};
+
+// Global flags affected by command line
+static uint64_t g_pgflags = 0;
+static uint64_t g_pgflags_mask = 0;
+static uint16_t g_mapflags_mask = 0;
+static bool g_all_libs = false;
+static bool g_has_swap = false;
+static bool g_reverse_sort = false;
+static std::string g_prefix_filter = "";
+
+static bool read_all_pids(std::function<bool(pid_t pid)> for_each_pid) {
+    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;
+    }
+
+    return true;
+}
+
+static bool scan_libs_per_process(pid_t pid) {
+    ProcMemInfo pmem(pid, false, g_pgflags, g_pgflags_mask);
+    const std::vector<Vma> maps = pmem.Maps();
+    if (maps.size() == 0) {
+        // nothing to do here, continue
+        return true;
+    }
+
+    ProcessRecord proc(pid);
+    if (!proc.valid()) {
+        fprintf(stderr, "Failed to create process record for process: %d\n", pid);
+        return false;
+    }
+
+    for (auto& map : maps) {
+        // skip library / map if prefix for the path doesn't match
+        if (!g_prefix_filter.empty() && !::android::base::StartsWith(map.name, g_prefix_filter)) {
+            continue;
+        }
+        // Skip maps based on map permissions
+        if (g_mapflags_mask &&
+            ((map.flags & (PROT_READ | PROT_WRITE | PROT_EXEC)) != g_mapflags_mask)) {
+            continue;
+        }
+
+        // skip blacklisted library / map names
+        if (!g_all_libs && (std::find(g_blacklisted_libs.begin(), g_blacklisted_libs.end(),
+                                      map.name) != g_blacklisted_libs.end())) {
+            continue;
+        }
+
+        auto lib = std::find_if(g_libs.begin(), g_libs.end(),
+                                [&](auto l) -> bool { return map.name == l.name(); });
+        if (lib == g_libs.end()) {
+            lib = g_libs.emplace(g_libs.end(), map.name);
+        }
+
+        lib->AddUsage(proc, map.usage);
+        if (!g_has_swap && map.usage.swap) {
+            g_has_swap = true;
+        }
+    }
+
+    return true;
+}
+
+static uint16_t parse_mapflags(const char* mapflags) {
+    uint16_t ret = 0;
+    for (const char* p = mapflags; *p; p++) {
+        switch (*p) {
+            case 'r':
+                ret |= PROT_READ;
+                break;
+            case 'w':
+                ret |= PROT_WRITE;
+                break;
+            case 'x':
+                ret |= PROT_EXEC;
+                break;
+            default:
+                error(EXIT_FAILURE, 0, "Invalid permissions string: %s, %s", mapflags, p);
+        }
+    }
+
+    return ret;
+}
+
+int main(int argc, char* argv[]) {
+    int opt;
+
+    auto pss_sort = [](const ProcessRecord& a, const ProcessRecord& b) {
+        return g_reverse_sort ? a.usage().pss < b.usage().pss : a.usage().pss > b.usage().pss;
+    };
+
+    auto uss_sort = [](const ProcessRecord& a, const ProcessRecord& b) {
+        return g_reverse_sort ? a.usage().uss < b.usage().uss : a.usage().uss > b.usage().uss;
+    };
+
+    auto vss_sort = [](const ProcessRecord& a, const ProcessRecord& b) {
+        return g_reverse_sort ? a.usage().vss < b.usage().vss : a.usage().vss > b.usage().vss;
+    };
+
+    auto rss_sort = [](const ProcessRecord& a, const ProcessRecord& b) {
+        return g_reverse_sort ? a.usage().rss < b.usage().rss : a.usage().rss > b.usage().rss;
+    };
+
+    auto swap_sort = [](const ProcessRecord& a, const ProcessRecord& b) {
+        return g_reverse_sort ? a.usage().swap < b.usage().swap : a.usage().swap > b.usage().swap;
+    };
+
+    std::function<bool(const ProcessRecord&, const ProcessRecord&)> sort_func = pss_sort;
+
+    while ((opt = getopt(argc, argv, "acChkm:pP:uvrsR")) != -1) {
+        switch (opt) {
+            case 'a':
+                g_all_libs = true;
+                break;
+            case 'c':
+                g_pgflags = 0;
+                g_pgflags_mask = (1 << KPF_SWAPBACKED);
+                break;
+            case 'C':
+                g_pgflags = g_pgflags_mask = (1 << KPF_SWAPBACKED);
+                break;
+            case 'h':
+                usage(argv[0], EXIT_SUCCESS);
+            case 'k':
+                g_pgflags = g_pgflags_mask = (1 << KPF_KSM);
+                break;
+            case 'm':
+                g_mapflags_mask = parse_mapflags(optarg);
+                break;
+            case 'p':
+                sort_func = pss_sort;
+                break;
+            case 'P':
+                g_prefix_filter = optarg;
+                break;
+            case 'u':
+                sort_func = uss_sort;
+                break;
+            case 'v':
+                sort_func = vss_sort;
+                break;
+            case 'r':
+                sort_func = rss_sort;
+                break;
+            case 's':
+                sort_func = swap_sort;
+                break;
+            case 'R':
+                g_reverse_sort = true;
+                break;
+            default:
+                usage(argv[0], EXIT_FAILURE);
+        }
+    }
+
+    if (!read_all_pids(scan_libs_per_process)) {
+        error(EXIT_FAILURE, 0, "Failed to read all pids from the system");
+    }
+
+    printf(" %6s   %7s   %6s   %6s   %6s  ", "RSStot", "VSS", "RSS", "PSS", "USS");
+    if (g_has_swap) {
+        printf(" %6s  ", "Swap");
+    }
+    printf("Name/PID\n");
+
+    // sort the libraries by their pss
+    std::sort(g_libs.begin(), g_libs.end(),
+              [](const LibRecord& l1, const LibRecord& l2) { return l1.pss() > l2.pss(); });
+
+    for (auto& lib : g_libs) {
+        printf("%6" PRIu64 "K   %7s   %6s   %6s   %6s  ", lib.pss() / 1024, "", "", "", "");
+        if (g_has_swap) {
+            printf(" %6s  ", "");
+        }
+        printf("%s\n", lib.name().c_str());
+
+        // sort all mappings first
+        lib.Sort(sort_func);
+
+        for (auto& p : lib.processes()) {
+            const MemUsage& usage = p.usage();
+            printf(" %6s  %7" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  %6" PRIu64 "K  ", "",
+                   usage.vss / 1024, usage.rss / 1024, usage.pss / 1024, usage.uss / 1024);
+            if (g_has_swap) {
+                printf("%6" PRIu64 "K  ", usage.swap / 1024);
+            }
+            printf("  %s [%d]\n", p.cmdline().c_str(), p.pid());
+        }
+    }
+
+    return 0;
+}
diff --git a/libnativeloader/native_loader.cpp b/libnativeloader/native_loader.cpp
index b3e2b97..de7ea08 100644
--- a/libnativeloader/native_loader.cpp
+++ b/libnativeloader/native_loader.cpp
@@ -639,7 +639,11 @@
   UNUSED(target_sdk_version);
   if (class_loader == nullptr) {
     *needs_native_bridge = false;
-    return dlopen(path, RTLD_NOW);
+    void* handle = dlopen(path, RTLD_NOW);
+    if (handle == nullptr) {
+      *error_msg = dlerror();
+    }
+    return handle;
   }
 
   std::lock_guard<std::mutex> guard(g_namespaces_mutex);
diff --git a/libstats/include/stats_event_list.h b/libstats/include/stats_event_list.h
index 41ca79b..162d1cf 100644
--- a/libstats/include/stats_event_list.h
+++ b/libstats/include/stats_event_list.h
@@ -24,7 +24,7 @@
 #endif
 void reset_log_context(android_log_context ctx);
 int write_to_logger(android_log_context context, log_id_t id);
-void note_log_drop();
+void note_log_drop(int error);
 void stats_log_close();
 int android_log_write_char_array(android_log_context ctx, const char* value, size_t len);
 #ifdef __cplusplus
diff --git a/libstats/stats_event_list.c b/libstats/stats_event_list.c
index f4a7e94..5b90361 100644
--- a/libstats/stats_event_list.c
+++ b/libstats/stats_event_list.c
@@ -120,8 +120,8 @@
     return retValue;
 }
 
-void note_log_drop() {
-    statsdLoggerWrite.noteDrop();
+void note_log_drop(int error) {
+    statsdLoggerWrite.noteDrop(error);
 }
 
 void stats_log_close() {
diff --git a/libstats/statsd_writer.c b/libstats/statsd_writer.c
index 88f7d44..f00fc2d 100644
--- a/libstats/statsd_writer.c
+++ b/libstats/statsd_writer.c
@@ -48,6 +48,7 @@
 
 static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
 static atomic_int dropped = 0;
+static atomic_int log_error = 0;
 
 void statsd_writer_init_lock() {
     /*
@@ -150,8 +151,9 @@
     return 1;
 }
 
-static void statsdNoteDrop() {
+static void statsdNoteDrop(int error) {
     atomic_fetch_add_explicit(&dropped, 1, memory_order_relaxed);
+    atomic_exchange_explicit(&log_error, error, memory_order_relaxed);
 }
 
 static int statsdWrite(struct timespec* ts, struct iovec* vec, size_t nr) {
@@ -202,7 +204,8 @@
         if (snapshot) {
             android_log_event_int_t buffer;
             header.id = LOG_ID_STATS;
-            buffer.header.tag = htole32(LIBLOG_LOG_TAG);
+            // store the last log error in the tag field. This tag field is not used by statsd.
+            buffer.header.tag = htole32(atomic_load(&log_error));
             buffer.payload.type = EVENT_TYPE_INT;
             buffer.payload.data = htole32(snapshot);
 
diff --git a/libstats/statsd_writer.h b/libstats/statsd_writer.h
index 7289441..4fc3f8b 100644
--- a/libstats/statsd_writer.h
+++ b/libstats/statsd_writer.h
@@ -39,7 +39,7 @@
     /* write log to transport, returns number of bytes propagated, or -errno */
     int (*write)(struct timespec* ts, struct iovec* vec, size_t nr);
     /* note one log drop */
-    void (*noteDrop)();
+    void (*noteDrop)(int error);
 };
 
 #endif  // ANDROID_STATS_LOG_STATS_WRITER_H
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index 4e0470e..89d4fc0 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -94,7 +94,10 @@
                 "DexFile.cpp",
                 "DexFiles.cpp",
             ],
-            exclude_shared_libs: ["libdexfile"],
+            exclude_shared_libs: [
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
         },
         recovery: {
             cflags: ["-DNO_LIBDEXFILE_SUPPORT"],
@@ -102,7 +105,10 @@
                 "DexFile.cpp",
                 "DexFiles.cpp",
             ],
-            exclude_shared_libs: ["libdexfile"],
+            exclude_shared_libs: [
+                "libdexfile_external",
+                "libdexfile_support",
+            ],
         },
     },
 
@@ -127,7 +133,8 @@
 
     shared_libs: [
         "libbase",
-        "libdexfile",
+        "libdexfile_external",
+        "libdexfile_support",
         "liblog",
         "liblzma",
     ],
@@ -215,6 +222,7 @@
         "liblzma",
         "libunwindstack",
         "libdexfile",
+        "libdexfile_support",
     ],
 
     static_libs: [
diff --git a/libunwindstack/DexFile.cpp b/libunwindstack/DexFile.cpp
index 8ec560c..9b0b232 100644
--- a/libunwindstack/DexFile.cpp
+++ b/libunwindstack/DexFile.cpp
@@ -23,13 +23,7 @@
 #include <memory>
 
 #include <android-base/unique_fd.h>
-
-#include <dex/class_accessor-inl.h>
-#include <dex/code_item_accessors-inl.h>
-#include <dex/compact_dex_file.h>
-#include <dex/dex_file-inl.h>
-#include <dex/dex_file_loader.h>
-#include <dex/standard_dex_file.h>
+#include <art_api/ext_dex_file.h>
 
 #include <unwindstack/MapInfo.h>
 #include <unwindstack/Memory.h>
@@ -38,169 +32,71 @@
 
 namespace unwindstack {
 
-DexFile* DexFile::Create(uint64_t dex_file_offset_in_memory, Memory* memory, MapInfo* info) {
+std::unique_ptr<DexFile> DexFile::Create(uint64_t dex_file_offset_in_memory, Memory* memory,
+                                         MapInfo* info) {
   if (!info->name.empty()) {
-    std::unique_ptr<DexFileFromFile> dex_file(new DexFileFromFile);
-    if (dex_file->Open(dex_file_offset_in_memory - info->start + info->offset, info->name)) {
-      return dex_file.release();
+    std::unique_ptr<DexFile> dex_file =
+        DexFileFromFile::Create(dex_file_offset_in_memory - info->start + info->offset, info->name);
+    if (dex_file) {
+      return dex_file;
     }
   }
-
-  std::unique_ptr<DexFileFromMemory> dex_file(new DexFileFromMemory);
-  if (dex_file->Open(dex_file_offset_in_memory, memory)) {
-    return dex_file.release();
-  }
-  return nullptr;
-}
-
-DexFileFromFile::~DexFileFromFile() {
-  if (size_ != 0) {
-    munmap(mapped_memory_, size_);
-  }
+  return DexFileFromMemory::Create(dex_file_offset_in_memory, memory, info->name);
 }
 
 bool DexFile::GetMethodInformation(uint64_t dex_offset, std::string* method_name,
                                    uint64_t* method_offset) {
-  if (dex_file_ == nullptr) {
+  art_api::dex::MethodInfo method_info = GetMethodInfoForOffset(dex_offset);
+  if (method_info.offset == 0) {
     return false;
   }
-
-  if (!dex_file_->IsInDataSection(dex_file_->Begin() + dex_offset)) {
-    return false;  // The DEX offset is not within the bytecode of this dex file.
-  }
-
-  if (dex_file_->IsCompactDexFile()) {
-    // The data section of compact dex files might be shared.
-    // Check the subrange unique to this compact dex.
-    const auto& cdex_header = dex_file_->AsCompactDexFile()->GetHeader();
-    uint32_t begin = cdex_header.data_off_ + cdex_header.OwnedDataBegin();
-    uint32_t end = cdex_header.data_off_ + cdex_header.OwnedDataEnd();
-    if (dex_offset < begin || dex_offset >= end) {
-      return false;  // The DEX offset is not within the bytecode of this dex file.
-    }
-  }
-
-  // The method data is cached in a std::map indexed by method end offset and
-  // contains the start offset and the method member index.
-  // Only cache the method data as it is searched. Do not read the entire
-  // set of method data into the cache at once.
-  // This is done because many unwinds only find a single frame with dex file
-  // info, so reading the entire method data is wasteful. However, still cache
-  // the data so that anything doing multiple unwinds will have this data
-  // cached for future use.
-
-  // First look in the method cache.
-  auto entry = method_cache_.upper_bound(dex_offset);
-  if (entry != method_cache_.end() && dex_offset >= entry->second.first) {
-    *method_name = dex_file_->PrettyMethod(entry->second.second, false);
-    *method_offset = dex_offset - entry->second.first;
-    return true;
-  }
-
-  // Check the methods we haven't cached.
-  for (; class_def_index_ < dex_file_->NumClassDefs(); class_def_index_++) {
-    art::ClassAccessor accessor(*dex_file_, dex_file_->GetClassDef(class_def_index_));
-
-    for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
-      art::CodeItemInstructionAccessor code = method.GetInstructions();
-      if (!code.HasCodeItem()) {
-        continue;
-      }
-      uint32_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - dex_file_->Begin();
-      uint32_t offset_end = offset + code.InsnsSizeInBytes();
-      uint32_t member_index = method.GetIndex();
-      method_cache_[offset_end] = std::make_pair(offset, member_index);
-      if (offset <= dex_offset && dex_offset < offset_end) {
-        *method_name = dex_file_->PrettyMethod(member_index, false);
-        *method_offset = dex_offset - offset;
-        return true;
-      }
-    }
-  }
-  return false;
+  *method_name = method_info.name;
+  *method_offset = dex_offset - method_info.offset;
+  return true;
 }
 
-bool DexFileFromFile::Open(uint64_t dex_file_offset_in_file, const std::string& file) {
+std::unique_ptr<DexFileFromFile> DexFileFromFile::Create(uint64_t dex_file_offset_in_file,
+                                                         const std::string& file) {
   android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(file.c_str(), O_RDONLY | O_CLOEXEC)));
   if (fd == -1) {
-    return false;
-  }
-  struct stat buf;
-  if (fstat(fd, &buf) == -1) {
-    return false;
-  }
-  uint64_t length;
-  if (buf.st_size < 0 ||
-      __builtin_add_overflow(dex_file_offset_in_file, sizeof(art::DexFile::Header), &length) ||
-      static_cast<uint64_t>(buf.st_size) < length) {
-    return false;
+    return nullptr;
   }
 
-  mapped_memory_ = mmap(nullptr, buf.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-  if (mapped_memory_ == MAP_FAILED) {
-    return false;
-  }
-  size_ = buf.st_size;
-
-  uint8_t* memory = reinterpret_cast<uint8_t*>(mapped_memory_);
-
-  art::DexFile::Header* header =
-      reinterpret_cast<art::DexFile::Header*>(&memory[dex_file_offset_in_file]);
-  if (!art::StandardDexFile::IsMagicValid(header->magic_) &&
-      !art::CompactDexFile::IsMagicValid(header->magic_)) {
-    return false;
-  }
-
-  if (__builtin_add_overflow(dex_file_offset_in_file, header->file_size_, &length) ||
-      static_cast<uint64_t>(buf.st_size) < length) {
-    return false;
-  }
-
-  art::DexFileLoader loader;
   std::string error_msg;
-  auto dex = loader.Open(&memory[dex_file_offset_in_file], header->file_size_, "", 0, nullptr,
-                         false, false, &error_msg);
-  dex_file_.reset(dex.release());
-  return dex_file_ != nullptr;
+  std::unique_ptr<art_api::dex::DexFile> art_dex_file =
+      OpenFromFd(fd, dex_file_offset_in_file, file, &error_msg);
+  if (art_dex_file == nullptr) {
+    return nullptr;
+  }
+
+  return std::unique_ptr<DexFileFromFile>(new DexFileFromFile(std::move(*art_dex_file.release())));
 }
 
-bool DexFileFromMemory::Open(uint64_t dex_file_offset_in_memory, Memory* memory) {
-  memory_.resize(sizeof(art::DexFile::Header));
-  if (!memory->ReadFully(dex_file_offset_in_memory, memory_.data(), memory_.size())) {
-    return false;
-  }
+std::unique_ptr<DexFileFromMemory> DexFileFromMemory::Create(uint64_t dex_file_offset_in_memory,
+                                                             Memory* memory,
+                                                             const std::string& name) {
+  std::vector<uint8_t> backing_memory;
 
-  art::DexFile::Header* header = reinterpret_cast<art::DexFile::Header*>(memory_.data());
-  uint32_t file_size = header->file_size_;
-  if (art::CompactDexFile::IsMagicValid(header->magic_)) {
-    // Compact dex file store data section separately so that it can be shared.
-    // Therefore we need to extend the read memory range to include it.
-    // TODO: This might be wasteful as we might read data in between as well.
-    //       In practice, this should be fine, as such sharing only happens on disk.
-    uint32_t computed_file_size;
-    if (__builtin_add_overflow(header->data_off_, header->data_size_, &computed_file_size)) {
-      return false;
+  for (size_t size = 0;;) {
+    std::string error_msg;
+    std::unique_ptr<art_api::dex::DexFile> art_dex_file =
+        OpenFromMemory(backing_memory.data(), &size, name, &error_msg);
+
+    if (art_dex_file != nullptr) {
+      return std::unique_ptr<DexFileFromMemory>(
+          new DexFileFromMemory(std::move(*art_dex_file.release()), std::move(backing_memory)));
     }
-    if (computed_file_size > file_size) {
-      file_size = computed_file_size;
+
+    if (!error_msg.empty()) {
+      return nullptr;
     }
-  } else if (!art::StandardDexFile::IsMagicValid(header->magic_)) {
-    return false;
+
+    backing_memory.resize(size);
+    if (!memory->ReadFully(dex_file_offset_in_memory, backing_memory.data(),
+                           backing_memory.size())) {
+      return nullptr;
+    }
   }
-
-  memory_.resize(file_size);
-  if (!memory->ReadFully(dex_file_offset_in_memory, memory_.data(), memory_.size())) {
-    return false;
-  }
-
-  header = reinterpret_cast<art::DexFile::Header*>(memory_.data());
-
-  art::DexFileLoader loader;
-  std::string error_msg;
-  auto dex =
-      loader.Open(memory_.data(), header->file_size_, "", 0, nullptr, false, false, &error_msg);
-  dex_file_.reset(dex.release());
-  return dex_file_ != nullptr;
 }
 
 }  // namespace unwindstack
diff --git a/libunwindstack/DexFile.h b/libunwindstack/DexFile.h
index c123158..5797dee 100644
--- a/libunwindstack/DexFile.h
+++ b/libunwindstack/DexFile.h
@@ -25,48 +25,41 @@
 #include <utility>
 #include <vector>
 
-#include <dex/dex_file-inl.h>
+#include <art_api/ext_dex_file.h>
 
 namespace unwindstack {
 
-class DexFile {
+class DexFile : protected art_api::dex::DexFile {
  public:
-  DexFile() = default;
   virtual ~DexFile() = default;
 
   bool GetMethodInformation(uint64_t dex_offset, std::string* method_name, uint64_t* method_offset);
 
-  static DexFile* Create(uint64_t dex_file_offset_in_memory, Memory* memory, MapInfo* info);
+  static std::unique_ptr<DexFile> Create(uint64_t dex_file_offset_in_memory, Memory* memory,
+                                         MapInfo* info);
 
  protected:
-  void Init();
-
-  std::unique_ptr<const art::DexFile> dex_file_;
-  std::map<uint32_t, std::pair<uint64_t, uint32_t>> method_cache_;  // dex offset to method index.
-
-  uint32_t class_def_index_ = 0;
+  DexFile(art_api::dex::DexFile&& art_dex_file) : art_api::dex::DexFile(std::move(art_dex_file)) {}
 };
 
 class DexFileFromFile : public DexFile {
  public:
-  DexFileFromFile() = default;
-  virtual ~DexFileFromFile();
-
-  bool Open(uint64_t dex_file_offset_in_file, const std::string& name);
+  static std::unique_ptr<DexFileFromFile> Create(uint64_t dex_file_offset_in_file,
+                                                 const std::string& file);
 
  private:
-  void* mapped_memory_ = nullptr;
-  size_t size_ = 0;
+  DexFileFromFile(art_api::dex::DexFile&& art_dex_file) : DexFile(std::move(art_dex_file)) {}
 };
 
 class DexFileFromMemory : public DexFile {
  public:
-  DexFileFromMemory() = default;
-  virtual ~DexFileFromMemory() = default;
-
-  bool Open(uint64_t dex_file_offset_in_memory, Memory* memory);
+  static std::unique_ptr<DexFileFromMemory> Create(uint64_t dex_file_offset_in_memory,
+                                                   Memory* memory, const std::string& name);
 
  private:
+  DexFileFromMemory(art_api::dex::DexFile&& art_dex_file, std::vector<uint8_t>&& memory)
+      : DexFile(std::move(art_dex_file)), memory_(std::move(memory)) {}
+
   std::vector<uint8_t> memory_;
 };
 
diff --git a/libunwindstack/DexFiles.cpp b/libunwindstack/DexFiles.cpp
index 451a0b9..63a77e5 100644
--- a/libunwindstack/DexFiles.cpp
+++ b/libunwindstack/DexFiles.cpp
@@ -48,11 +48,7 @@
 DexFiles::DexFiles(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)
     : Global(memory, search_libs) {}
 
-DexFiles::~DexFiles() {
-  for (auto& entry : files_) {
-    delete entry.second;
-  }
-}
+DexFiles::~DexFiles() {}
 
 void DexFiles::ProcessArch() {
   switch (arch()) {
@@ -137,10 +133,11 @@
   DexFile* dex_file;
   auto entry = files_.find(dex_file_offset);
   if (entry == files_.end()) {
-    dex_file = DexFile::Create(dex_file_offset, memory_.get(), info);
-    files_[dex_file_offset] = dex_file;
+    std::unique_ptr<DexFile> new_dex_file = DexFile::Create(dex_file_offset, memory_.get(), info);
+    dex_file = new_dex_file.get();
+    files_[dex_file_offset] = std::move(new_dex_file);
   } else {
-    dex_file = entry->second;
+    dex_file = entry->second.get();
   }
   return dex_file;
 }
diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index 44ec5c1..39a09cf 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -32,33 +32,27 @@
 bool MapInfo::InitFileMemoryFromPreviousReadOnlyMap(MemoryFileAtOffset* memory) {
   // One last attempt, see if the previous map is read-only with the
   // same name and stretches across this map.
-  for (auto iter = maps_->begin(); iter != maps_->end(); ++iter) {
-    if (*iter == this) {
-      if (iter == maps_->begin()) {
-        return false;
-      }
-      --iter;
-      MapInfo* prev_map = *iter;
-      // Make sure this is a read-only map.
-      if (prev_map->flags != PROT_READ) {
-        return false;
-      }
-      uint64_t map_size = end - prev_map->end;
-      if (!memory->Init(name, prev_map->offset, map_size)) {
-        return false;
-      }
-      uint64_t max_size;
-      if (!Elf::GetInfo(memory, &max_size) || max_size < map_size) {
-        return false;
-      }
-      if (!memory->Init(name, prev_map->offset, max_size)) {
-        return false;
-      }
-      elf_offset = offset - prev_map->offset;
-      return true;
-    }
+  if (prev_map == nullptr || prev_map->flags != PROT_READ) {
+    return false;
   }
-  return false;
+
+  uint64_t map_size = end - prev_map->end;
+  if (!memory->Init(name, prev_map->offset, map_size)) {
+    return false;
+  }
+
+  uint64_t max_size;
+  if (!Elf::GetInfo(memory, &max_size) || max_size < map_size) {
+    return false;
+  }
+
+  if (!memory->Init(name, prev_map->offset, max_size)) {
+    return false;
+  }
+
+  elf_offset = offset - prev_map->offset;
+  elf_start_offset = prev_map->offset;
+  return true;
 }
 
 Memory* MapInfo::GetFileMemory() {
@@ -91,14 +85,13 @@
 
   // Check if the start of this map is an embedded elf.
   uint64_t max_size = 0;
-  uint64_t file_offset = offset;
   if (Elf::GetInfo(memory.get(), &max_size)) {
     if (max_size > map_size) {
-      if (memory->Init(name, file_offset, max_size)) {
+      if (memory->Init(name, offset, max_size)) {
         return memory.release();
       }
       // Try to reinit using the default map_size.
-      if (memory->Init(name, file_offset, map_size)) {
+      if (memory->Init(name, offset, map_size)) {
         return memory.release();
       }
       return nullptr;
@@ -109,6 +102,13 @@
   // No elf at offset, try to init as if the whole file is an elf.
   if (memory->Init(name, 0) && Elf::IsValidElf(memory.get())) {
     elf_offset = offset;
+    // Need to check how to set the elf start offset. If this map is not
+    // the r-x map of a r-- map, then use the real offset value. Otherwise,
+    // use 0.
+    if (prev_map == nullptr || prev_map->offset != 0 || prev_map->flags != PROT_READ ||
+        prev_map->name != name) {
+      elf_start_offset = offset;
+    }
     return memory.release();
   }
 
@@ -156,35 +156,24 @@
     return memory.release();
   }
 
-  if (name.empty() || maps_ == nullptr) {
-    return nullptr;
-  }
-
   // Find the read-only map by looking at the previous map. The linker
   // doesn't guarantee that this invariant will always be true. However,
   // if that changes, there is likely something else that will change and
   // break something.
-  MapInfo* ro_map_info = nullptr;
-  for (auto iter = maps_->begin(); iter != maps_->end(); ++iter) {
-    if (*iter == this) {
-      if (iter != maps_->begin()) {
-        --iter;
-        ro_map_info = *iter;
-      }
-      break;
-    }
-  }
-
-  if (ro_map_info == nullptr || ro_map_info->name != name || ro_map_info->offset >= offset) {
+  if (offset == 0 || name.empty() || prev_map == nullptr || prev_map->name != name ||
+      prev_map->offset >= offset) {
     return nullptr;
   }
 
   // Make sure that relative pc values are corrected properly.
-  elf_offset = offset - ro_map_info->offset;
+  elf_offset = offset - prev_map->offset;
+  // Use this as the elf start offset, otherwise, you always get offsets into
+  // the r-x section, which is not quite the right information.
+  elf_start_offset = prev_map->offset;
 
   MemoryRanges* ranges = new MemoryRanges;
-  ranges->Insert(new MemoryRange(process_memory, ro_map_info->start,
-                                 ro_map_info->end - ro_map_info->start, 0));
+  ranges->Insert(
+      new MemoryRange(process_memory, prev_map->start, prev_map->end - prev_map->start, 0));
   ranges->Insert(new MemoryRange(process_memory, start, end - start, elf_offset));
 
   return ranges;
diff --git a/libunwindstack/Maps.cpp b/libunwindstack/Maps.cpp
index a9fb859..c90e383 100644
--- a/libunwindstack/Maps.cpp
+++ b/libunwindstack/Maps.cpp
@@ -67,13 +67,15 @@
         if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
           flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
         }
-        maps_.push_back(new MapInfo(this, start, end, pgoff, flags, name));
+        maps_.push_back(
+            new MapInfo(maps_.empty() ? nullptr : maps_.back(), start, end, pgoff, flags, name));
       });
 }
 
 void Maps::Add(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
                const std::string& name, uint64_t load_bias) {
-  MapInfo* map_info = new MapInfo(this, start, end, offset, flags, name);
+  MapInfo* map_info =
+      new MapInfo(maps_.empty() ? nullptr : maps_.back(), start, end, offset, flags, name);
   map_info->load_bias = load_bias;
   maps_.push_back(map_info);
 }
@@ -81,6 +83,13 @@
 void Maps::Sort() {
   std::sort(maps_.begin(), maps_.end(),
             [](const MapInfo* a, const MapInfo* b) { return a->start < b->start; });
+
+  // Set the prev_map values on the info objects.
+  MapInfo* prev_map = nullptr;
+  for (MapInfo* map_info : maps_) {
+    map_info->prev_map = prev_map;
+    prev_map = map_info;
+  }
 }
 
 Maps::~Maps() {
@@ -98,7 +107,8 @@
         if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
           flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
         }
-        maps_.push_back(new MapInfo(this, start, end, pgoff, flags, name));
+        maps_.push_back(
+            new MapInfo(maps_.empty() ? nullptr : maps_.back(), start, end, pgoff, flags, name));
       });
 }
 
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 792cd0b..8133639 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -59,7 +59,8 @@
   if (info != nullptr) {
     frame->map_start = info->start;
     frame->map_end = info->end;
-    frame->map_offset = info->offset;
+    frame->map_elf_start_offset = info->elf_start_offset;
+    frame->map_exact_offset = info->offset;
     frame->map_load_bias = info->load_bias;
     frame->map_flags = info->flags;
     if (resolve_names_) {
@@ -102,7 +103,8 @@
   if (resolve_names_) {
     frame->map_name = map_info->name;
   }
-  frame->map_offset = map_info->offset;
+  frame->map_elf_start_offset = map_info->elf_start_offset;
+  frame->map_exact_offset = map_info->offset;
   frame->map_start = map_info->start;
   frame->map_end = map_info->end;
   frame->map_flags = map_info->flags;
@@ -290,10 +292,6 @@
     data += android::base::StringPrintf("  #%02zu pc %016" PRIx64, frame.num, frame.rel_pc);
   }
 
-  if (frame.map_offset != 0) {
-    data += android::base::StringPrintf(" (offset 0x%" PRIx64 ")", frame.map_offset);
-  }
-
   if (frame.map_start == frame.map_end) {
     // No valid map associated with this frame.
     data += "  <unknown>";
@@ -302,6 +300,11 @@
   } else {
     data += android::base::StringPrintf("  <anonymous:%" PRIx64 ">", frame.map_start);
   }
+
+  if (frame.map_elf_start_offset != 0) {
+    data += android::base::StringPrintf(" (offset 0x%" PRIx64 ")", frame.map_elf_start_offset);
+  }
+
   if (!frame.function_name.empty()) {
     data += " (" + frame.function_name;
     if (frame.function_offset != 0) {
diff --git a/libunwindstack/include/unwindstack/DexFiles.h b/libunwindstack/include/unwindstack/DexFiles.h
index c202a33..0336173 100644
--- a/libunwindstack/include/unwindstack/DexFiles.h
+++ b/libunwindstack/include/unwindstack/DexFiles.h
@@ -66,7 +66,7 @@
 
   std::mutex lock_;
   bool initialized_ = false;
-  std::unordered_map<uint64_t, DexFile*> files_;
+  std::unordered_map<uint64_t, std::unique_ptr<DexFile>> files_;
 
   uint64_t entry_addr_ = 0;
   uint64_t (DexFiles::*read_entry_ptr_func_)(uint64_t) = nullptr;
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index cfdefd0..5e3d6f6 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -25,38 +25,31 @@
 #include <string>
 
 #include <unwindstack/Elf.h>
+#include <unwindstack/Memory.h>
 
 namespace unwindstack {
 
-// Forward declarations.
-class Maps;
-class Memory;
-
 struct MapInfo {
-  MapInfo(Maps* maps) : maps_(maps) {}
-  MapInfo(Maps* maps, uint64_t start, uint64_t end) : maps_(maps), start(start), end(end) {}
-  MapInfo(Maps* maps, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+  MapInfo(MapInfo* map_info, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
           const char* name)
-      : maps_(maps),
-        start(start),
+      : start(start),
         end(end),
         offset(offset),
         flags(flags),
         name(name),
+        prev_map(map_info),
         load_bias(static_cast<uint64_t>(-1)) {}
-  MapInfo(Maps* maps, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+  MapInfo(MapInfo* map_info, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
           const std::string& name)
-      : maps_(maps),
-        start(start),
+      : start(start),
         end(end),
         offset(offset),
         flags(flags),
         name(name),
+        prev_map(map_info),
         load_bias(static_cast<uint64_t>(-1)) {}
   ~MapInfo() = default;
 
-  Maps* maps_ = nullptr;
-
   uint64_t start = 0;
   uint64_t end = 0;
   uint64_t offset = 0;
@@ -64,10 +57,14 @@
   std::string name;
   std::shared_ptr<Elf> elf;
   // This value is only non-zero if the offset is non-zero but there is
-  // no elf signature found at that offset. This indicates that the
-  // entire file is represented by the Memory object returned by CreateMemory,
-  // instead of a portion of the file.
+  // no elf signature found at that offset.
   uint64_t elf_offset = 0;
+  // This value is the offset from the map in memory that is the start
+  // of the elf. This is not equal to offset when the linker splits
+  // shared libraries into a read-only and read-execute map.
+  uint64_t elf_start_offset = 0;
+
+  MapInfo* prev_map = nullptr;
 
   std::atomic_uint64_t load_bias;
 
diff --git a/libunwindstack/include/unwindstack/Unwinder.h b/libunwindstack/include/unwindstack/Unwinder.h
index 56b0581..d7bbd9d 100644
--- a/libunwindstack/include/unwindstack/Unwinder.h
+++ b/libunwindstack/include/unwindstack/Unwinder.h
@@ -48,7 +48,13 @@
   uint64_t function_offset = 0;
 
   std::string map_name;
-  uint64_t map_offset = 0;
+  // The offset from the first map representing the frame. When there are
+  // two maps (read-only and read-execute) this will be the offset from
+  // the read-only map. When there is only one map, this will be the
+  // same as the actual offset of the map and match map_exact_offset.
+  uint64_t map_elf_start_offset = 0;
+  // The actual offset from the map where the pc lies.
+  uint64_t map_exact_offset = 0;
   uint64_t map_start = 0;
   uint64_t map_end = 0;
   uint64_t map_load_bias = 0;
diff --git a/libunwindstack/tests/DexFileTest.cpp b/libunwindstack/tests/DexFileTest.cpp
index 95d2176..21ca47b 100644
--- a/libunwindstack/tests/DexFileTest.cpp
+++ b/libunwindstack/tests/DexFileTest.cpp
@@ -21,44 +21,37 @@
 #include <unordered_map>
 
 #include <android-base/file.h>
-
+#include <dex/dex_file.h>
+#include <gtest/gtest.h>
 #include <unwindstack/MapInfo.h>
 #include <unwindstack/Memory.h>
 
-#include <dex/code_item_accessors-inl.h>
-#include <dex/standard_dex_file.h>
-
-#include <gtest/gtest.h>
-
 #include "DexFile.h"
-
 #include "DexFileData.h"
 #include "MemoryFake.h"
 
 namespace unwindstack {
 
 TEST(DexFileTest, from_file_open_non_exist) {
-  DexFileFromFile dex_file;
-  ASSERT_FALSE(dex_file.Open(0, "/file/does/not/exist"));
+  EXPECT_TRUE(DexFileFromFile::Create(0, "/file/does/not/exist") == nullptr);
 }
 
 TEST(DexFileTest, from_file_open_too_small) {
   TemporaryFile tf;
   ASSERT_TRUE(tf.fd != -1);
 
-  ASSERT_EQ(sizeof(art::DexFile::Header) - 2,
+  ASSERT_EQ(sizeof(art::DexFile::Header) - 1,
             static_cast<size_t>(
-                TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(art::DexFile::Header)) - 2)));
+                TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(art::DexFile::Header) - 1))));
 
   // Header too small.
-  DexFileFromFile dex_file;
-  ASSERT_FALSE(dex_file.Open(0, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0, tf.path) == nullptr);
 
   // Header correct, file too small.
   ASSERT_EQ(0, lseek(tf.fd, 0, SEEK_SET));
   ASSERT_EQ(sizeof(art::DexFile::Header), static_cast<size_t>(TEMP_FAILURE_RETRY(write(
                                               tf.fd, kDexData, sizeof(art::DexFile::Header)))));
-  ASSERT_FALSE(dex_file.Open(0, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0, tf.path) == nullptr);
 }
 
 TEST(DexFileTest, from_file_open) {
@@ -68,8 +61,7 @@
   ASSERT_EQ(sizeof(kDexData),
             static_cast<size_t>(TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(kDexData)))));
 
-  DexFileFromFile dex_file;
-  ASSERT_TRUE(dex_file.Open(0, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0, tf.path) != nullptr);
 }
 
 TEST(DexFileTest, from_file_open_non_zero_offset) {
@@ -80,35 +72,31 @@
   ASSERT_EQ(sizeof(kDexData),
             static_cast<size_t>(TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(kDexData)))));
 
-  DexFileFromFile dex_file;
-  ASSERT_TRUE(dex_file.Open(0x100, tf.path));
+  EXPECT_TRUE(DexFileFromFile::Create(0x100, tf.path) != nullptr);
 }
 
 TEST(DexFileTest, from_memory_fail_too_small_for_header) {
   MemoryFake memory;
 
   memory.SetMemory(0x1000, kDexData, sizeof(art::DexFile::Header) - 1);
-  DexFileFromMemory dex_file;
 
-  ASSERT_FALSE(dex_file.Open(0x1000, &memory));
+  EXPECT_TRUE(DexFileFromMemory::Create(0x1000, &memory, "") == nullptr);
 }
 
 TEST(DexFileTest, from_memory_fail_too_small_for_data) {
   MemoryFake memory;
 
   memory.SetMemory(0x1000, kDexData, sizeof(kDexData) - 2);
-  DexFileFromMemory dex_file;
 
-  ASSERT_FALSE(dex_file.Open(0x1000, &memory));
+  EXPECT_TRUE(DexFileFromMemory::Create(0x1000, &memory, "") == nullptr);
 }
 
 TEST(DexFileTest, from_memory_open) {
   MemoryFake memory;
 
   memory.SetMemory(0x1000, kDexData, sizeof(kDexData));
-  DexFileFromMemory dex_file;
 
-  ASSERT_TRUE(dex_file.Open(0x1000, &memory));
+  EXPECT_TRUE(DexFileFromMemory::Create(0x1000, &memory, "") != nullptr);
 }
 
 TEST(DexFileTest, create_using_file) {
@@ -121,8 +109,7 @@
 
   MemoryFake memory;
   MapInfo info(nullptr, 0, 0x10000, 0, 0x5, tf.path);
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x500, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x500, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_file_non_zero_start) {
@@ -135,8 +122,7 @@
 
   MemoryFake memory;
   MapInfo info(nullptr, 0x100, 0x10000, 0, 0x5, tf.path);
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x600, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x600, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_file_non_zero_offset) {
@@ -149,24 +135,21 @@
 
   MemoryFake memory;
   MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, tf.path);
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x400, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x400, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_memory_empty_file) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
   MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "");
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x4000, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_memory_file_does_not_exist) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
   MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "/does/not/exist");
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
-  ASSERT_TRUE(dex_file != nullptr);
+  EXPECT_TRUE(DexFile::Create(0x4000, &memory, &info) != nullptr);
 }
 
 TEST(DexFileTest, create_using_memory_file_is_malformed) {
@@ -179,22 +162,13 @@
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
   MapInfo info(nullptr, 0x4000, 0x10000, 0x200, 0x5, "/does/not/exist");
-  std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
+  std::unique_ptr<DexFile> dex_file = DexFile::Create(0x4000, &memory, &info);
   ASSERT_TRUE(dex_file != nullptr);
 
   // Check it came from memory by clearing memory and verifying it fails.
   memory.Clear();
-  dex_file.reset(DexFile::Create(0x4000, &memory, &info));
-  ASSERT_TRUE(dex_file == nullptr);
-}
-
-TEST(DexFileTest, get_method_not_opened) {
-  std::string method("something");
-  uint64_t method_offset = 100;
-  DexFile dex_file;
-  dex_file.GetMethodInformation(0x100, &method, &method_offset);
-  EXPECT_EQ("something", method);
-  EXPECT_EQ(100U, method_offset);
+  dex_file = DexFile::Create(0x4000, &memory, &info);
+  EXPECT_TRUE(dex_file == nullptr);
 }
 
 TEST(DexFileTest, get_method) {
diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index 7766218..f7689ce 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -269,7 +269,7 @@
   elf.FakeSetInterface(interface);
 
   elf.FakeSetValid(true);
-  MapInfo map_info(nullptr, 0x1000, 0x2000);
+  MapInfo map_info(nullptr, 0x1000, 0x2000, 0, 0, "");
 
   ASSERT_EQ(0x101U, elf.GetRelPc(0x1101, &map_info));
 
diff --git a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
index 943b3c9..a66685a 100644
--- a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
+++ b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
@@ -118,6 +118,7 @@
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
 
   // Read the entire file.
   std::vector<uint8_t> buffer(1024);
@@ -129,6 +130,44 @@
   }
 
   ASSERT_FALSE(memory->ReadFully(1024, buffer.data(), 1));
+
+  // Now verify the elf start offset is set correctly based on the previous
+  // info.
+  MapInfo prev_info(nullptr, 0, 0x100, 0x10, 0, "");
+  info.prev_map = &prev_info;
+
+  // No preconditions met, change each one until it should set the elf start
+  // offset to zero.
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
+
+  prev_info.offset = 0;
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
+
+  prev_info.flags = PROT_READ;
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0x100U, info.elf_start_offset);
+
+  prev_info.name = info.name;
+  info.elf_offset = 0;
+  info.elf_start_offset = 0;
+  memory.reset(info.CreateMemory(process_memory_));
+  ASSERT_TRUE(memory.get() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 }
 
 // Verify that if the offset is non-zero and there is an elf at that
@@ -139,6 +178,7 @@
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 
   // Read the valid part of the file.
   std::vector<uint8_t> buffer(0x100);
@@ -162,6 +202,7 @@
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 
   // Verify the memory is a valid elf.
   uint8_t e_ident[SELFMAG + 1];
@@ -178,6 +219,7 @@
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
+  EXPECT_EQ(0U, info.elf_start_offset);
 
   // Verify the memory is a valid elf.
   uint8_t e_ident[SELFMAG + 1];
@@ -250,6 +292,7 @@
   ASSERT_TRUE(mem.get() != nullptr);
   EXPECT_EQ(0x4000UL, map_info->elf_offset);
   EXPECT_EQ(0x4000UL, map_info->offset);
+  EXPECT_EQ(0U, map_info->elf_start_offset);
 
   // Verify that reading values from this memory works properly.
   std::vector<uint8_t> buffer(0x4000);
@@ -295,6 +338,7 @@
   ASSERT_TRUE(mem.get() != nullptr);
   EXPECT_EQ(0x1000UL, map_info->elf_offset);
   EXPECT_EQ(0xb000UL, map_info->offset);
+  EXPECT_EQ(0xa000UL, map_info->elf_start_offset);
 
   // Verify that reading values from this memory works properly.
   std::vector<uint8_t> buffer(0x4000);
@@ -333,6 +377,7 @@
   std::vector<uint8_t> buffer(0x100);
   EXPECT_EQ(0x2000U, map_info->offset);
   EXPECT_EQ(0U, map_info->elf_offset);
+  EXPECT_EQ(0U, map_info->elf_start_offset);
   ASSERT_TRUE(memory->ReadFully(0, buffer.data(), 0x100));
   EXPECT_EQ(0xffU, buffer[0]);
 
@@ -346,6 +391,7 @@
   memory.reset(map_info->CreateMemory(process_memory_));
   EXPECT_EQ(0x2000U, map_info->offset);
   EXPECT_EQ(0x1000U, map_info->elf_offset);
+  EXPECT_EQ(0x1000U, map_info->elf_start_offset);
   Elf64_Ehdr ehdr_mem;
   ASSERT_TRUE(memory->ReadFully(0, &ehdr_mem, sizeof(ehdr_mem)));
   EXPECT_TRUE(memcmp(&ehdr, &ehdr_mem, sizeof(ehdr)) == 0);
diff --git a/libunwindstack/tests/MapsTest.cpp b/libunwindstack/tests/MapsTest.cpp
index 80e292a..b4197f2 100644
--- a/libunwindstack/tests/MapsTest.cpp
+++ b/libunwindstack/tests/MapsTest.cpp
@@ -62,7 +62,7 @@
 }
 
 TEST(MapsTest, verify_parse_line) {
-  MapInfo info(nullptr);
+  MapInfo info(nullptr, 0, 0, 0, 0, "");
 
   VerifyLine("01-02 rwxp 03 04:05 06\n", &info);
   EXPECT_EQ(1U, info.start);
@@ -135,7 +135,7 @@
 }
 
 TEST(MapsTest, verify_large_values) {
-  MapInfo info(nullptr);
+  MapInfo info(nullptr, 0, 0, 0, 0, "");
 #if defined(__LP64__)
   VerifyLine("fabcdef012345678-f12345678abcdef8 rwxp f0b0d0f010305070 00:00 0\n", &info);
   EXPECT_EQ(0xfabcdef012345678UL, info.start);
diff --git a/libunwindstack/tests/RegsTest.cpp b/libunwindstack/tests/RegsTest.cpp
index 00264c2..472d1cf 100644
--- a/libunwindstack/tests/RegsTest.cpp
+++ b/libunwindstack/tests/RegsTest.cpp
@@ -182,7 +182,7 @@
   RegsX86_64 regs_x86_64;
   RegsMips regs_mips;
   RegsMips64 regs_mips64;
-  MapInfo map_info(nullptr, 0x1000, 0x2000);
+  MapInfo map_info(nullptr, 0x1000, 0x2000, 0, 0, "");
   Elf* invalid_elf = new Elf(nullptr);
   map_info.elf.reset(invalid_elf);
 
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
index dc015b4..aab9ec2 100644
--- a/libunwindstack/tests/UnwindOfflineTest.cpp
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -298,7 +298,7 @@
   EXPECT_EQ(
       "  #00 pc 00068fb8  libarttestd.so (_ZN3artL13CauseSegfaultEv+72)\n"
       "  #01 pc 00067f00  libarttestd.so (Java_Main_unwindInProcess+10032)\n"
-      "  #02 pc 000021a8 (offset 0x2000)  137-cfi.odex (boolean Main.unwindInProcess(boolean, int, "
+      "  #02 pc 000021a8  137-cfi.odex (offset 0x2000) (boolean Main.unwindInProcess(boolean, int, "
       "boolean)+136)\n"
       "  #03 pc 0000fe80  anonymous:ee74c000 (boolean Main.bar(boolean)+64)\n"
       "  #04 pc 006ad4d2  libartd.so (art_quick_invoke_stub+338)\n"
@@ -591,7 +591,7 @@
   ASSERT_EQ(76U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
   EXPECT_EQ(
       "  #00 pc 00018a5e  libarttestd.so (Java_Main_unwindInProcess+866)\n"
-      "  #01 pc 0000212d (offset 0x2000)  137-cfi.odex (boolean Main.unwindInProcess(boolean, int, "
+      "  #01 pc 0000212d  137-cfi.odex (offset 0x2000) (boolean Main.unwindInProcess(boolean, int, "
       "boolean)+92)\n"
       "  #02 pc 00011cb1  anonymous:e2796000 (boolean Main.bar(boolean)+72)\n"
       "  #03 pc 00462175  libartd.so (art_quick_invoke_stub_internal+68)\n"
@@ -1135,29 +1135,29 @@
   std::string frame_info(DumpFrames(unwinder));
   ASSERT_EQ(19U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
   EXPECT_EQ(
-      "  #00 pc 0032bfa0 (offset 0x42000)  libunwindstack_test (SignalInnerFunction+40)\n"
-      "  #01 pc 0032bfeb (offset 0x42000)  libunwindstack_test (SignalMiddleFunction+2)\n"
-      "  #02 pc 0032bff3 (offset 0x42000)  libunwindstack_test (SignalOuterFunction+2)\n"
-      "  #03 pc 0032fed3 (offset 0x42000)  libunwindstack_test "
+      "  #00 pc 0032bfa0  libunwindstack_test (SignalInnerFunction+40)\n"
+      "  #01 pc 0032bfeb  libunwindstack_test (SignalMiddleFunction+2)\n"
+      "  #02 pc 0032bff3  libunwindstack_test (SignalOuterFunction+2)\n"
+      "  #03 pc 0032fed3  libunwindstack_test "
       "(_ZN11unwindstackL19SignalCallerHandlerEiP7siginfoPv+26)\n"
-      "  #04 pc 00026528 (offset 0x25000)  libc.so\n"
+      "  #04 pc 00026528  libc.so\n"
       "  #05 pc 00000000  <unknown>\n"
-      "  #06 pc 0032c2d9 (offset 0x42000)  libunwindstack_test (InnerFunction+736)\n"
-      "  #07 pc 0032cc4f (offset 0x42000)  libunwindstack_test (MiddleFunction+42)\n"
-      "  #08 pc 0032cc81 (offset 0x42000)  libunwindstack_test (OuterFunction+42)\n"
-      "  #09 pc 0032e547 (offset 0x42000)  libunwindstack_test "
+      "  #06 pc 0032c2d9  libunwindstack_test (InnerFunction+736)\n"
+      "  #07 pc 0032cc4f  libunwindstack_test (MiddleFunction+42)\n"
+      "  #08 pc 0032cc81  libunwindstack_test (OuterFunction+42)\n"
+      "  #09 pc 0032e547  libunwindstack_test "
       "(_ZN11unwindstackL19RemoteThroughSignalEij+270)\n"
-      "  #10 pc 0032ed99 (offset 0x42000)  libunwindstack_test "
+      "  #10 pc 0032ed99  libunwindstack_test "
       "(_ZN11unwindstack55UnwindTest_remote_through_signal_with_invalid_func_Test8TestBodyEv+16)\n"
-      "  #11 pc 00354453 (offset 0x42000)  libunwindstack_test (_ZN7testing4Test3RunEv+154)\n"
-      "  #12 pc 00354de7 (offset 0x42000)  libunwindstack_test (_ZN7testing8TestInfo3RunEv+194)\n"
-      "  #13 pc 00355105 (offset 0x42000)  libunwindstack_test (_ZN7testing8TestCase3RunEv+180)\n"
-      "  #14 pc 0035a215 (offset 0x42000)  libunwindstack_test "
+      "  #11 pc 00354453  libunwindstack_test (_ZN7testing4Test3RunEv+154)\n"
+      "  #12 pc 00354de7  libunwindstack_test (_ZN7testing8TestInfo3RunEv+194)\n"
+      "  #13 pc 00355105  libunwindstack_test (_ZN7testing8TestCase3RunEv+180)\n"
+      "  #14 pc 0035a215  libunwindstack_test "
       "(_ZN7testing8internal12UnitTestImpl11RunAllTestsEv+664)\n"
-      "  #15 pc 00359f4f (offset 0x42000)  libunwindstack_test (_ZN7testing8UnitTest3RunEv+110)\n"
-      "  #16 pc 0034d3db (offset 0x42000)  libunwindstack_test (main+38)\n"
-      "  #17 pc 00092c0d (offset 0x25000)  libc.so (__libc_init+48)\n"
-      "  #18 pc 0004202f (offset 0x42000)  libunwindstack_test (_start_main+38)\n",
+      "  #15 pc 00359f4f  libunwindstack_test (_ZN7testing8UnitTest3RunEv+110)\n"
+      "  #16 pc 0034d3db  libunwindstack_test (main+38)\n"
+      "  #17 pc 00092c0d  libc.so (__libc_init+48)\n"
+      "  #18 pc 0004202f  libunwindstack_test (_start_main+38)\n",
       frame_info);
 
   EXPECT_EQ(0x2e55fa0U, unwinder.frames()[0].pc);
@@ -1248,14 +1248,14 @@
   std::string frame_info(DumpFrames(unwinder));
   ASSERT_EQ(7U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
   EXPECT_EQ(
-      "  #00 pc 000000000014ccbc (offset 0x39000)  linker64 (__dl_syscall+28)\n"
-      "  #01 pc 000000000005426c (offset 0x39000)  linker64 "
+      "  #00 pc 000000000014ccbc  linker64 (__dl_syscall+28)\n"
+      "  #01 pc 000000000005426c  linker64 "
       "(__dl__ZL24debuggerd_signal_handleriP7siginfoPv+1128)\n"
       "  #02 pc 00000000000008bc  vdso.so\n"
-      "  #03 pc 00000000000846f4 (offset 0x40000)  libc.so (abort+172)\n"
-      "  #04 pc 0000000000084ad4 (offset 0x40000)  libc.so (__assert2+36)\n"
-      "  #05 pc 000000000003d5b4 (offset 0x40000)  ANGLEPrebuilt.apk (ANGLEGetUtilityAPI+56)\n"
-      "  #06 pc 000000000007fe68 (offset 0x40000)  libc.so (__libc_init)\n",
+      "  #03 pc 00000000000846f4  libc.so (abort+172)\n"
+      "  #04 pc 0000000000084ad4  libc.so (__assert2+36)\n"
+      "  #05 pc 000000000003d5b4  ANGLEPrebuilt.apk (offset 0x4000) (ANGLEGetUtilityAPI+56)\n"
+      "  #06 pc 000000000007fe68  libc.so (__libc_init)\n",
       frame_info);
 
   EXPECT_EQ(0x7e82c4fcbcULL, unwinder.frames()[0].pc);
@@ -1287,14 +1287,14 @@
   std::string frame_info(DumpFrames(unwinder));
   ASSERT_EQ(7U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
   EXPECT_EQ(
-      "  #00 pc 000000000014ccbc (offset 0x39000)  linker64 (__dl_syscall+28)\n"
-      "  #01 pc 000000000005426c (offset 0x39000)  linker64 "
+      "  #00 pc 000000000014ccbc  linker64 (__dl_syscall+28)\n"
+      "  #01 pc 000000000005426c  linker64 "
       "(__dl__ZL24debuggerd_signal_handleriP7siginfoPv+1128)\n"
       "  #02 pc 00000000000008bc  vdso.so\n"
-      "  #03 pc 00000000000846f4 (offset 0x40000)  libc.so (abort+172)\n"
-      "  #04 pc 0000000000084ad4 (offset 0x40000)  libc.so (__assert2+36)\n"
-      "  #05 pc 000000000003d5b4 (offset 0x2211000)  ANGLEPrebuilt.apk\n"
-      "  #06 pc 000000000007fe68 (offset 0x40000)  libc.so (__libc_init)\n",
+      "  #03 pc 00000000000846f4  libc.so (abort+172)\n"
+      "  #04 pc 0000000000084ad4  libc.so (__assert2+36)\n"
+      "  #05 pc 000000000003d5b4  ANGLEPrebuilt.apk (offset 0x21d5000)\n"
+      "  #06 pc 000000000007fe68  libc.so (__libc_init)\n",
       frame_info);
 
   EXPECT_EQ(0x7e82c4fcbcULL, unwinder.frames()[0].pc);
diff --git a/libunwindstack/tests/UnwinderTest.cpp b/libunwindstack/tests/UnwinderTest.cpp
index c4b8763..1fdeee5 100644
--- a/libunwindstack/tests/UnwinderTest.cpp
+++ b/libunwindstack/tests/UnwinderTest.cpp
@@ -42,84 +42,64 @@
 
 namespace unwindstack {
 
-class MapsFake : public Maps {
- public:
-  MapsFake() = default;
-  virtual ~MapsFake() = default;
-
-  bool Parse() { return true; }
-
-  void FakeClear() { maps_.clear(); }
-
-  void FakeAddMapInfo(MapInfo* map_info) { maps_.push_back(map_info); }
-};
-
 class UnwinderTest : public ::testing::Test {
  protected:
+  static void AddMapInfo(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+                         const char* name, Elf* elf = nullptr) {
+    std::string str_name(name);
+    maps_->Add(start, end, offset, flags, name, static_cast<uint64_t>(-1));
+    if (elf != nullptr) {
+      MapInfo* map_info = *--maps_->end();
+      map_info->elf.reset(elf);
+    }
+  }
+
   static void SetUpTestCase() {
-    maps_.FakeClear();
-    MapInfo* info =
-        new MapInfo(&maps_, 0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so");
+    maps_.reset(new Maps);
+
     ElfFake* elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so", elf);
 
-    info = new MapInfo(&maps_, 0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
 
-    info = new MapInfo(&maps_, 0x13000, 0x15000, 0, PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP,
-                       "/dev/fake_device");
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x13000, 0x15000, 0, PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP,
+               "/dev/fake_device");
 
-    info = new MapInfo(&maps_, 0x20000, 0x22000, 0, PROT_READ | PROT_WRITE,
-                       "/system/fake/libunwind.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x20000, 0x22000, 0, PROT_READ | PROT_WRITE, "/system/fake/libunwind.so", elf);
 
-    info = new MapInfo(&maps_, 0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so", elf);
 
-    info = new MapInfo(&maps_, 0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so", elf);
 
-    info = new MapInfo(&maps_, 0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk", elf);
 
-    info = new MapInfo(&maps_, 0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
 
-    info = new MapInfo(&maps_, 0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
-                       "/fake/fake.vdex");
+    AddMapInfo(0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake.vdex");
+    MapInfo* info = *--maps_->end();
     info->load_bias = 0;
-    maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(&maps_, 0xa5000, 0xa6000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
-                       "/fake/fake_load_bias.so");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     elf->FakeSetLoadBias(0x5000);
-    maps_.FakeAddMapInfo(info);
+    AddMapInfo(0xa5000, 0xa6000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake_load_bias.so",
+               elf);
 
-    info = new MapInfo(&maps_, 0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
-                       "/fake/fake_offset.oat");
     elf = new ElfFake(new MemoryFake);
-    info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
+    AddMapInfo(0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake_offset.oat",
+               elf);
+    info = *--maps_->end();
     info->elf_offset = 0x8000;
-    maps_.FakeAddMapInfo(info);
 
     process_memory_.reset(new MemoryFake);
   }
@@ -130,12 +110,12 @@
     regs_.FakeSetReturnAddressValid(false);
   }
 
-  static MapsFake maps_;
+  static std::unique_ptr<Maps> maps_;
   static RegsFake regs_;
   static std::shared_ptr<Memory> process_memory_;
 };
 
-MapsFake UnwinderTest::maps_;
+std::unique_ptr<Maps> UnwinderTest::maps_;
 RegsFake UnwinderTest::regs_(5);
 std::shared_ptr<Memory> UnwinderTest::process_memory_(nullptr);
 
@@ -150,7 +130,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x1202, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -164,7 +144,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -178,7 +159,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -192,7 +174,8 @@
   EXPECT_EQ("Frame2", frame->function_name);
   EXPECT_EQ(2U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -210,7 +193,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x1202, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.SetResolveNames(false);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
@@ -225,7 +208,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -239,7 +223,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -253,7 +238,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -267,7 +253,7 @@
   regs_.set_sp(0x10000);
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -281,7 +267,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake_load_bias.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa5000U, frame->map_start);
   EXPECT_EQ(0xa6000U, frame->map_end);
   EXPECT_EQ(0x5000U, frame->map_load_bias);
@@ -295,7 +282,7 @@
   regs_.set_sp(0x10000);
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -309,7 +296,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake_offset.oat", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa7000U, frame->map_start);
   EXPECT_EQ(0xa8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -323,7 +311,7 @@
   regs_.set_sp(0x10000);
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -337,7 +325,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.apk", frame->map_name);
-  EXPECT_EQ(0x1d000U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0x1d000U, frame->map_exact_offset);
   EXPECT_EQ(0x43000U, frame->map_start);
   EXPECT_EQ(0x44000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -358,7 +347,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x1102, 0x10010, false));
   ElfInterfaceFake::FakePushStepData(StepData(0x1202, 0x10020, false));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -372,7 +361,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -389,7 +379,7 @@
   regs_.set_pc(0x1000);
   regs_.set_sp(0x10000);
 
-  Unwinder unwinder(20, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(20, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_MAX_FRAMES_EXCEEDED, unwinder.LastErrorCode());
 
@@ -404,7 +394,8 @@
     EXPECT_EQ("Frame" + std::to_string(i), frame->function_name) << "Failed at frame " << i;
     EXPECT_EQ(i, frame->function_offset) << "Failed at frame " << i;
     EXPECT_EQ("/system/fake/libc.so", frame->map_name) << "Failed at frame " << i;
-    EXPECT_EQ(0U, frame->map_offset) << "Failed at frame " << i;
+    EXPECT_EQ(0U, frame->map_elf_start_offset) << "Failed at frame " << i;
+    EXPECT_EQ(0U, frame->map_exact_offset) << "Failed at frame " << i;
     EXPECT_EQ(0x1000U, frame->map_start) << "Failed at frame " << i;
     EXPECT_EQ(0x8000U, frame->map_end) << "Failed at frame " << i;
     EXPECT_EQ(0U, frame->map_load_bias) << "Failed at frame " << i;
@@ -429,7 +420,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23002, 0x10070, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   std::vector<std::string> skip_libs{"libunwind.so", "libanother.so"};
   unwinder.Unwind(&skip_libs);
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
@@ -444,7 +435,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -458,7 +450,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x20000U, frame->map_start);
   EXPECT_EQ(0x22000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -472,7 +465,7 @@
   EXPECT_EQ("Frame2", frame->function_name);
   EXPECT_EQ(2U, frame->function_offset);
   EXPECT_EQ("/fake/libanother.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x23000U, frame->map_start);
   EXPECT_EQ(0x24000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -489,7 +482,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x21002, 0x50020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -503,7 +496,7 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -517,7 +510,7 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x20000U, frame->map_start);
   EXPECT_EQ(0x22000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -536,7 +529,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23102, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -555,7 +548,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23102, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -569,7 +562,7 @@
   regs_.set_pc(0x41000);
   regs_.set_sp(0x13000);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());
 
@@ -583,7 +576,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -604,7 +598,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x23102, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -618,7 +612,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -632,7 +627,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -646,7 +642,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/libanother.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x23000U, frame->map_start);
   EXPECT_EQ(0x24000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -666,7 +663,7 @@
   regs_.FakeSetReturnAddress(0x12);
   regs_.FakeSetReturnAddressValid(true);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_INVALID_MAP, unwinder.LastErrorCode());
 
@@ -680,7 +677,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libunwind.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x20000U, frame->map_start);
   EXPECT_EQ(0x22000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -694,7 +692,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -713,7 +712,7 @@
   regs_.FakeSetReturnAddress(0x1202);
   regs_.FakeSetReturnAddressValid(true);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -727,7 +726,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -741,7 +741,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -762,14 +763,14 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x53502, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   std::vector<std::string> suffixes{"oat"};
   unwinder.Unwind(nullptr, &suffixes);
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
   ASSERT_EQ(2U, unwinder.NumFrames());
   // Make sure the elf was not initialized.
-  MapInfo* map_info = maps_.Find(0x53000);
+  MapInfo* map_info = maps_->Find(0x53000);
   ASSERT_TRUE(map_info != nullptr);
   EXPECT_TRUE(map_info->elf == nullptr);
 
@@ -781,7 +782,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -795,7 +797,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/fake.apk", frame->map_name);
-  EXPECT_EQ(0x1d000U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0x1d000U, frame->map_exact_offset);
   EXPECT_EQ(0x43000U, frame->map_start);
   EXPECT_EQ(0x44000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -819,7 +822,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x33502, 0x10020, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_REPEATED_FRAME, unwinder.LastErrorCode());
 
@@ -833,7 +836,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -847,7 +851,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/compressed.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x33000U, frame->map_start);
   EXPECT_EQ(0x34000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -861,7 +866,8 @@
   EXPECT_EQ("Frame2", frame->function_name);
   EXPECT_EQ(2U, frame->function_offset);
   EXPECT_EQ("/fake/compressed.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x33000U, frame->map_start);
   EXPECT_EQ(0x34000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -874,7 +880,7 @@
   regs_.set_sp(0x10000);
   regs_.FakeSetDexPc(0xa3400);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -888,7 +894,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.vdex", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa3000U, frame->map_start);
   EXPECT_EQ(0xa4000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -902,7 +909,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -915,7 +923,7 @@
   regs_.set_sp(0x10000);
   regs_.FakeSetDexPc(0x50000);
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -929,7 +937,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0U, frame->map_start);
   EXPECT_EQ(0U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -943,7 +952,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -959,7 +969,7 @@
   ElfInterfaceFake::FakePushStepData(StepData(0x33402, 0x10010, false));
   ElfInterfaceFake::FakePushStepData(StepData(0, 0, true));
 
-  Unwinder unwinder(64, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(64, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_NONE, unwinder.LastErrorCode());
 
@@ -973,7 +983,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.vdex", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa3000U, frame->map_start);
   EXPECT_EQ(0xa4000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -987,7 +998,8 @@
   EXPECT_EQ("Frame0", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/system/fake/libc.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -1001,7 +1013,8 @@
   EXPECT_EQ("Frame1", frame->function_name);
   EXPECT_EQ(1U, frame->function_offset);
   EXPECT_EQ("/fake/compressed.so", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0x33000U, frame->map_start);
   EXPECT_EQ(0x34000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -1014,7 +1027,7 @@
   regs_.set_sp(0x10000);
   regs_.FakeSetDexPc(0xa3400);
 
-  Unwinder unwinder(1, &maps_, &regs_, process_memory_);
+  Unwinder unwinder(1, maps_.get(), &regs_, process_memory_);
   unwinder.Unwind();
   EXPECT_EQ(ERROR_MAX_FRAMES_EXCEEDED, unwinder.LastErrorCode());
 
@@ -1028,7 +1041,8 @@
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
   EXPECT_EQ("/fake/fake.vdex", frame->map_name);
-  EXPECT_EQ(0U, frame->map_offset);
+  EXPECT_EQ(0U, frame->map_elf_start_offset);
+  EXPECT_EQ(0U, frame->map_exact_offset);
   EXPECT_EQ(0xa3000U, frame->map_start);
   EXPECT_EQ(0xa4000U, frame->map_end);
   EXPECT_EQ(0U, frame->map_load_bias);
@@ -1045,17 +1059,17 @@
   frame.function_name = "function";
   frame.function_offset = 100;
   frame.map_name = "/fake/libfake.so";
-  frame.map_offset = 0x2000;
+  frame.map_elf_start_offset = 0x2000;
   frame.map_start = 0x3000;
   frame.map_end = 0x6000;
   frame.map_flags = PROT_READ;
 
-  EXPECT_EQ("  #01 pc 0000000000001000 (offset 0x2000)  /fake/libfake.so (function+100)",
+  EXPECT_EQ("  #01 pc 0000000000001000  /fake/libfake.so (offset 0x2000) (function+100)",
             Unwinder::FormatFrame(frame, false));
-  EXPECT_EQ("  #01 pc 00001000 (offset 0x2000)  /fake/libfake.so (function+100)",
+  EXPECT_EQ("  #01 pc 00001000  /fake/libfake.so (offset 0x2000) (function+100)",
             Unwinder::FormatFrame(frame, true));
 
-  frame.map_offset = 0;
+  frame.map_elf_start_offset = 0;
   EXPECT_EQ("  #01 pc 0000000000001000  /fake/libfake.so (function+100)",
             Unwinder::FormatFrame(frame, false));
   EXPECT_EQ("  #01 pc 00001000  /fake/libfake.so (function+100)",
@@ -1130,7 +1144,7 @@
   for (auto regs : reg_list) {
     ElfInterfaceFake::FakePushFunctionData(FunctionData("Frame0", 10));
 
-    Unwinder unwinder(64, &maps_, regs, process_memory_);
+    Unwinder unwinder(64, maps_.get(), regs, process_memory_);
     unwinder.Unwind();
 
     ASSERT_EQ(1U, unwinder.NumFrames());
diff --git a/libunwindstack/tests/files/offline/offset_arm/maps.txt b/libunwindstack/tests/files/offline/offset_arm/maps.txt
index 6224464..768dd9f 100644
--- a/libunwindstack/tests/files/offline/offset_arm/maps.txt
+++ b/libunwindstack/tests/files/offline/offset_arm/maps.txt
@@ -1,2 +1,4 @@
+2b2a000-2b6c000 r--p 0 00:00 0   libunwindstack_test
 2b6c000-2e92000 r-xp 42000 00:00 0   libunwindstack_test
+f4110000-f4135000 r--p 0 00:00 0   libc.so
 f4135000-f41a9000 r-xp 25000 00:00 0   libc.so
diff --git a/libunwindstack/tools/unwind_for_offline.cpp b/libunwindstack/tools/unwind_for_offline.cpp
index 652dbd1..5ae8874 100644
--- a/libunwindstack/tools/unwind_for_offline.cpp
+++ b/libunwindstack/tools/unwind_for_offline.cpp
@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <sys/ptrace.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -46,6 +47,7 @@
   uint64_t start;
   uint64_t end;
   uint64_t offset;
+  uint64_t flags;
   std::string name;
 };
 
@@ -163,14 +165,19 @@
   return true;
 }
 
-bool CopyElfFromFile(map_info_t* info) {
+bool CopyElfFromFile(map_info_t* info, bool* file_copied) {
+  std::string cur_name = basename(info->name.c_str());
+  if (*file_copied) {
+    info->name = cur_name;
+    return true;
+  }
+
   std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(info->name.c_str(), "r"), &fclose);
   if (fp == nullptr) {
     perror((std::string("Cannot open ") + info->name).c_str());
     return false;
   }
 
-  std::string cur_name = basename(info->name.c_str());
   std::unique_ptr<FILE, decltype(&fclose)> output(fopen(cur_name.c_str(), "w+"), &fclose);
   if (output == nullptr) {
     perror((std::string("Cannot create file " + cur_name)).c_str());
@@ -193,6 +200,39 @@
   return true;
 }
 
+map_info_t* FillInAndGetMapInfo(std::unordered_map<uint64_t, map_info_t>& maps_by_start,
+                                unwindstack::MapInfo* map_info) {
+  auto info = &maps_by_start[map_info->start];
+  info->start = map_info->start;
+  info->end = map_info->end;
+  info->offset = map_info->offset;
+  info->name = map_info->name;
+  info->flags = map_info->flags;
+
+  return info;
+}
+
+void SaveMapInformation(std::shared_ptr<unwindstack::Memory>& process_memory, map_info_t* info,
+                        bool* file_copied) {
+  if (CopyElfFromFile(info, file_copied)) {
+    return;
+  }
+  *file_copied = false;
+
+  // Try to create the elf from memory, this will handle cases where
+  // the data only exists in memory such as vdso data on x86.
+  if (CreateElfFromMemory(process_memory, info)) {
+    return;
+  }
+
+  printf("Cannot save memory or file for map ");
+  if (!info->name.empty()) {
+    printf("%s\n", info->name.c_str());
+  } else {
+    printf("anonymous:%" PRIx64 "\n", info->start);
+  }
+}
+
 int SaveData(pid_t pid) {
   unwindstack::Regs* regs = unwindstack::Regs::RemoteGet(pid);
   if (regs == nullptr) {
@@ -237,22 +277,21 @@
     }
 
     if (maps_by_start.count(frame.map_start) == 0) {
-      auto info = &maps_by_start[frame.map_start];
-      info->start = frame.map_start;
-      info->end = frame.map_end;
-      info->offset = frame.map_offset;
-      info->name = frame.map_name;
-      if (!CopyElfFromFile(info)) {
-        // Try to create the elf from memory, this will handle cases where
-        // the data only exists in memory such as vdso data on x86.
-        if (!CreateElfFromMemory(process_memory, info)) {
-          printf("Ignoring map ");
-          if (!info->name.empty()) {
-            printf("%s\n", info->name.c_str());
-          } else {
-            printf("anonymous:%" PRIx64 "\n", info->start);
-          }
-        }
+      map_info = maps.Find(frame.map_start);
+
+      auto info = FillInAndGetMapInfo(maps_by_start, map_info);
+      bool file_copied = false;
+      SaveMapInformation(process_memory, info, &file_copied);
+
+      // If you are using a a linker that creates two maps (one read-only, one
+      // read-executable), it's necessary to capture the previous map
+      // information if needed.
+      unwindstack::MapInfo* prev_map = map_info->prev_map;
+      if (prev_map != nullptr && map_info->offset != 0 && prev_map->offset == 0 &&
+          prev_map->flags == PROT_READ && map_info->name == prev_map->name &&
+          maps_by_start.count(prev_map->start) == 0) {
+        info = FillInAndGetMapInfo(maps_by_start, prev_map);
+        SaveMapInformation(process_memory, info, &file_copied);
       }
     }
   }
@@ -277,8 +316,18 @@
   }
 
   for (auto& element : sorted_maps) {
+    char perms[5] = {"---p"};
     map_info_t& map = element.second;
-    fprintf(fp.get(), "%" PRIx64 "-%" PRIx64 " r-xp %" PRIx64 " 00:00 0", map.start, map.end,
+    if (map.flags & PROT_READ) {
+      perms[0] = 'r';
+    }
+    if (map.flags & PROT_WRITE) {
+      perms[1] = 'w';
+    }
+    if (map.flags & PROT_EXEC) {
+      perms[2] = 'x';
+    }
+    fprintf(fp.get(), "%" PRIx64 "-%" PRIx64 " %s %" PRIx64 " 00:00 0", map.start, map.end, perms,
             map.offset);
     if (!map.name.empty()) {
       fprintf(fp.get(), "   %s", map.name.c_str());
diff --git a/libutils/Looper.cpp b/libutils/Looper.cpp
index 102fdf0..b3f943d 100644
--- a/libutils/Looper.cpp
+++ b/libutils/Looper.cpp
@@ -51,9 +51,6 @@
 
 // --- Looper ---
 
-// Hint for number of file descriptors to be associated with the epoll instance.
-static const int EPOLL_SIZE_HINT = 8;
-
 // Maximum number of file descriptors for which to retrieve poll events each iteration.
 static const int EPOLL_MAX_EVENTS = 16;
 
@@ -139,7 +136,7 @@
     }
 
     // Allocate the new epoll instance and register the wake pipe.
-    mEpollFd.reset(epoll_create(EPOLL_SIZE_HINT));
+    mEpollFd.reset(epoll_create1(EPOLL_CLOEXEC));
     LOG_ALWAYS_FATAL_IF(mEpollFd < 0, "Could not create epoll instance: %s", strerror(errno));
 
     struct epoll_event eventItem;
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index 9eb7f2c..6b9f6e1 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -491,7 +491,7 @@
 }
 
 int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle) {
-  const int fd = ::android::base::utf8::open(fileName, O_RDONLY | O_BINARY, 0);
+  const int fd = ::android::base::utf8::open(fileName, O_RDONLY | O_BINARY | O_CLOEXEC, 0);
   ZipArchive* archive = new ZipArchive(fd, true);
   *handle = archive;
 
diff --git a/llkd/README.md b/llkd/README.md
index 3da7a2f..224e184 100644
--- a/llkd/README.md
+++ b/llkd/README.md
@@ -160,7 +160,7 @@
 NB: false is a very very very unlikely process to want to blacklist.
 
 #### ro.llk.blacklist.parent
-default 0,2 (kernel and [kthreadd]).
+default 0,2,adbd (kernel, [kthreadd] and adbd).
 The string "*false*" is the equivalent to an *empty* list.
 Do not watch processes that have this parent.
 A parent process can be comm, cmdline or pid reference.
diff --git a/llkd/include/llkd.h b/llkd/include/llkd.h
index b16b1d8..1efa32b 100644
--- a/llkd/include/llkd.h
+++ b/llkd/include/llkd.h
@@ -55,7 +55,11 @@
 #define LLK_BLACKLIST_PROCESS_DEFAULT  \
     "0,1,2,init,[kthreadd],[khungtaskd],lmkd,llkd,watchdogd,[watchdogd],[watchdogd/0]"
 #define LLK_BLACKLIST_PARENT_PROPERTY  "ro.llk.blacklist.parent"
+#ifdef __PTRACE_ENABLED__  // defined if userdebug build
+#define LLK_BLACKLIST_PARENT_DEFAULT   "0,2,[kthreadd],adbd"
+#else
 #define LLK_BLACKLIST_PARENT_DEFAULT   "0,2,[kthreadd]"
+#endif
 #define LLK_BLACKLIST_UID_PROPERTY     "ro.llk.blacklist.uid"
 #define LLK_BLACKLIST_UID_DEFAULT      ""
 #define LLK_BLACKLIST_STACK_PROPERTY   "ro.llk.blacklist.process.stack"
diff --git a/llkd/libllkd.cpp b/llkd/libllkd.cpp
index 969f26b..267da4a 100644
--- a/llkd/libllkd.cpp
+++ b/llkd/libllkd.cpp
@@ -510,9 +510,7 @@
     return android::base::Trim(content) == string;
 }
 
-void llkPanicKernel(bool dump, pid_t tid, const char* state,
-                    const std::string& message = "") __noreturn;
-void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message) {
+void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message = "") {
     if (!message.empty()) LOG(ERROR) << message;
     auto sysrqTriggerFd = llkFileToWriteFd("/proc/sysrq-trigger");
     if (sysrqTriggerFd < 0) {
@@ -521,6 +519,7 @@
         // The answer to life, the universe and everything
         ::exit(42);
         // NOTREACHED
+        return;
     }
     ::sync();
     if (dump) {
@@ -544,6 +543,13 @@
     llkWriteStringToFile(message + (message.empty() ? "" : "\n") +
                                  "SysRq : Trigger a crash : 'livelock,"s + state + "'\n",
                          "/dev/kmsg");
+    // Because panic is such a serious thing to do, let us
+    // make sure that the tid being inspected still exists!
+    auto piddir = procdir + std::to_string(tid) + "/stat";
+    if (access(piddir.c_str(), F_OK) != 0) {
+        PLOG(WARNING) << piddir;
+        return;
+    }
     android::base::WriteStringToFd("c", sysrqTriggerFd);
     // NOTREACHED
     // DYB
@@ -909,6 +915,7 @@
     ms -= llkCycle;
     auto myPid = ::getpid();
     auto myTid = ::gettid();
+    auto dump = true;
     for (auto dp = llkTopDirectory.read(); dp != nullptr; dp = llkTopDirectory.read()) {
         std::string piddir;
 
@@ -1109,9 +1116,10 @@
             const auto message = state + " "s + llkFormat(procp->count) + " " +
                                  std::to_string(ppid) + "->" + std::to_string(pid) + "->" +
                                  std::to_string(tid) + " " + procp->getComm() + " [panic]";
-            llkPanicKernel(true, tid,
+            llkPanicKernel(dump, tid,
                            (state == 'Z') ? "zombie" : (state == 'D') ? "driver" : "sleeping",
                            message);
+            dump = false;
         }
         LOG(VERBOSE) << "+closedir()";
     }
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index 19e6d68..2fd9f95 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -55,8 +55,19 @@
       mMsgLen(elem.mMsgLen),
       mLogId(elem.mLogId),
       mDropped(elem.mDropped) {
-    mMsg = new char[mMsgLen];
-    memcpy(mMsg, elem.mMsg, mMsgLen);
+    if (mDropped) {
+        if (elem.isBinary() && elem.mMsg != nullptr) {
+            // for the following "len" value, refer to : setDropped(uint16_t value), getTag()
+            const int len = sizeof(android_event_header_t);
+            mMsg = new char[len];
+            memcpy(mMsg, elem.mMsg, len);
+        } else {
+            mMsg = nullptr;
+        }
+    } else {
+        mMsg = new char[mMsgLen];
+        memcpy(mMsg, elem.mMsg, mMsgLen);
+    }
 }
 
 LogBufferElement::~LogBufferElement() {
diff --git a/rootdir/etc/ld.config.txt b/rootdir/etc/ld.config.txt
index 264c612..e510c3c 100644
--- a/rootdir/etc/ld.config.txt
+++ b/rootdir/etc/ld.config.txt
@@ -28,7 +28,7 @@
 dir.postinstall = /postinstall
 
 [system]
-additional.namespaces = runtime,sphal,vndk,rs
+additional.namespaces = sphal,vndk,rs
 
 ###############################################################################
 # "default" namespace
@@ -73,6 +73,7 @@
 namespace.default.permitted.paths += /%PRODUCT_SERVICES%/priv-app
 namespace.default.permitted.paths += /data
 namespace.default.permitted.paths += /mnt/expand
+namespace.default.permitted.paths += /apex/com.android.resolv/${LIB}
 
 namespace.default.asan.search.paths  = /data/asan/system/${LIB}
 namespace.default.asan.search.paths +=           /system/${LIB}
@@ -105,28 +106,6 @@
 namespace.default.asan.permitted.paths += /%PRODUCT_SERVICES%/priv-app
 namespace.default.asan.permitted.paths += /mnt/expand
 
-# Keep in sync with ld.config.txt in the com.android.runtime APEX.
-namespace.default.links = runtime
-namespace.default.link.runtime.shared_libs  = libc.so:libdl.so:libm.so
-namespace.default.link.runtime.shared_libs += libart.so:libartd.so
-namespace.default.link.runtime.shared_libs += libnativebridge.so
-namespace.default.link.runtime.shared_libs += libnativehelper.so
-namespace.default.link.runtime.shared_libs += libnativeloader.so
-
-###############################################################################
-# "runtime" APEX namespace
-#
-# This namespace exposes externally accessible libraries from the Runtime APEX.
-###############################################################################
-namespace.runtime.isolated = true
-
-# Keep in sync with ld.config.txt in the com.android.runtime APEX.
-namespace.runtime.search.paths = /apex/com.android.runtime/${LIB}
-namespace.runtime.links = default
-# TODO(b/119867084): Restrict to Bionic dlopen dependencies and PALette library
-# when it exists.
-namespace.runtime.link.default.allow_all_shared_libs = true
-
 ###############################################################################
 # "sphal" namespace
 #
@@ -161,12 +140,8 @@
 
 # Once in this namespace, access to libraries in /system/lib is restricted. Only
 # libs listed here can be used.
-namespace.sphal.links = runtime,default,vndk,rs
+namespace.sphal.links = default,vndk,rs
 
-namespace.sphal.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-# LLNDK_LIBRARIES includes the runtime libs above, but the order here ensures
-# that they are loaded from the runtime namespace.
 namespace.sphal.link.default.shared_libs  = %LLNDK_LIBRARIES%
 namespace.sphal.link.default.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
 
@@ -213,11 +188,9 @@
 namespace.rs.asan.permitted.paths +=           /vendor/${LIB}
 namespace.rs.asan.permitted.paths += /data
 
-namespace.rs.links = runtime,default,vndk
+namespace.rs.links = default,vndk
 
-namespace.rs.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-namespace.rs.link.default.shared_libs  = %LLNDK_LIBRARIES%
+namespace.rs.link.default.shared_libs  =  %LLNDK_LIBRARIES%
 namespace.rs.link.default.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
 # Private LLNDK libs (e.g. libft2.so) are exceptionally allowed to this
 # namespace because RS framework libs are using them.
@@ -263,13 +236,10 @@
 namespace.vndk.asan.permitted.paths += /data/asan/system/${LIB}/vndk-sp%VNDK_VER%/hw
 namespace.vndk.asan.permitted.paths +=           /system/${LIB}/vndk-sp%VNDK_VER%/hw
 
-# The "vndk" namespace links to "runtime" for Bionic libs, "default" namespace
-# for LLNDK libs, and links to "sphal" namespace for vendor libs. The ordering
-# matters. The "default" namespace has higher priority than the "sphal"
-# namespace.
-namespace.vndk.links = runtime,default,sphal
-
-namespace.vndk.link.runtime.shared_libs = libc.so:libdl.so:libm.so
+# The "vndk" namespace links to "default" namespace for LLNDK libs and links to
+# "sphal" namespace for vendor libs.  The ordering matters.  The "default"
+# namespace has higher priority than the "sphal" namespace.
+namespace.vndk.links = default,sphal
 
 # When these NDK libs are required inside this namespace, then it is redirected
 # to the default namespace. This is possible since their ABI is stable across
@@ -280,7 +250,6 @@
 # Allow VNDK-SP extensions to use vendor libraries
 namespace.vndk.link.sphal.allow_all_shared_libs = true
 
-
 ###############################################################################
 # Namespace config for vendor processes. In O, no restriction is enforced for
 # them. However, in O-MR1, access to /system/${LIB} will not be allowed to
@@ -288,7 +257,7 @@
 # (LL-NDK only) access.
 ###############################################################################
 [vendor]
-additional.namespaces = runtime,system,vndk
+additional.namespaces = system,vndk
 
 ###############################################################################
 # "default" namespace
@@ -319,24 +288,12 @@
 namespace.default.asan.permitted.paths += /data/asan/vendor
 namespace.default.asan.permitted.paths +=           /vendor
 
-namespace.default.links = runtime,system,vndk
-namespace.default.link.runtime.shared_libs = libc.so:libdl.so:libm.so
+namespace.default.links = system,vndk
 namespace.default.link.system.shared_libs = %LLNDK_LIBRARIES%
 namespace.default.link.vndk.shared_libs  = %VNDK_SAMEPROCESS_LIBRARIES%
 namespace.default.link.vndk.shared_libs += %VNDK_CORE_LIBRARIES%
 
 ###############################################################################
-# "runtime" APEX namespace
-#
-# This namespace pulls in externally accessible libs from the Runtime APEX.
-###############################################################################
-namespace.runtime.isolated = true
-namespace.runtime.search.paths = /apex/com.android.runtime/${LIB}
-namespace.runtime.links = default
-# TODO(b/119867084): Restrict to Bionic dlopen dependencies.
-namespace.runtime.link.default.allow_all_shared_libs = true
-
-###############################################################################
 # "vndk" namespace
 #
 # This namespace is where VNDK and VNDK-SP libraries are loaded for
@@ -367,10 +324,7 @@
 # When these NDK libs are required inside this namespace, then it is redirected
 # to the system namespace. This is possible since their ABI is stable across
 # Android releases.
-namespace.vndk.links = runtime,system,default
-
-namespace.vndk.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
+namespace.vndk.links = system,default
 namespace.vndk.link.system.shared_libs  = %LLNDK_LIBRARIES%
 namespace.vndk.link.system.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
 
@@ -395,36 +349,16 @@
 namespace.system.asan.search.paths += /data/asan/product_services/${LIB}
 namespace.system.asan.search.paths +=           /%PRODUCT_SERVICES%/${LIB}
 
-namespace.system.links = runtime
-namespace.system.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-
 ###############################################################################
 # Namespace config for binaries under /postinstall.
-# Only default and runtime namespaces are defined and default 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 postinstall binaries. There is no
-# reason to allow the binaries to access the paths.
+# 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.
 ###############################################################################
 [postinstall]
-additional.namespaces = runtime
-
 namespace.default.isolated = false
 namespace.default.search.paths  = /system/${LIB}
 namespace.default.search.paths += /%PRODUCT%/${LIB}
 namespace.default.search.paths += /%PRODUCT_SERVICES%/${LIB}
-
-namespace.default.links = runtime
-namespace.default.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-###############################################################################
-# "runtime" APEX namespace
-#
-# This namespace pulls in externally accessible libs from the Runtime APEX.
-###############################################################################
-namespace.runtime.isolated = true
-namespace.runtime.search.paths = /apex/com.android.runtime/${LIB}
-namespace.runtime.links = default
-# TODO(b/119867084): Restrict to Bionic dlopen dependencies.
-namespace.runtime.link.default.allow_all_shared_libs = true
diff --git a/rootdir/etc/ld.config.vndk_lite.txt b/rootdir/etc/ld.config.vndk_lite.txt
index 7ca45ff..7e354ac 100644
--- a/rootdir/etc/ld.config.vndk_lite.txt
+++ b/rootdir/etc/ld.config.vndk_lite.txt
@@ -28,7 +28,7 @@
 dir.postinstall = /postinstall
 
 [system]
-additional.namespaces = runtime,sphal,vndk,rs
+additional.namespaces = sphal,vndk,rs
 
 ###############################################################################
 # "default" namespace
@@ -55,27 +55,6 @@
 namespace.default.asan.search.paths += /data/asan/product_services/${LIB}
 namespace.default.asan.search.paths +=           /%PRODUCT_SERVICES%/${LIB}
 
-# Keep in sync with ld.config.txt in the com.android.runtime APEX.
-namespace.default.links = runtime
-namespace.default.link.runtime.shared_libs  = libc.so:libdl.so:libm.so
-namespace.default.link.runtime.shared_libs += libart.so:libartd.so
-namespace.default.link.runtime.shared_libs += libnativehelper.so
-namespace.default.link.runtime.shared_libs += libnativeloader.so
-
-###############################################################################
-# "runtime" APEX namespace
-#
-# This namespace pulls in externally accessible libs from the Runtime APEX.
-###############################################################################
-namespace.runtime.isolated = true
-
-# Keep in sync with ld.config.txt in the com.android.runtime APEX.
-namespace.runtime.search.paths = /apex/com.android.runtime/${LIB}
-namespace.runtime.links = default
-# TODO(b/119867084): Restrict to Bionic dlopen dependencies and PALette library
-# when it exists.
-namespace.runtime.link.default.allow_all_shared_libs = true
-
 ###############################################################################
 # "sphal" namespace
 #
@@ -110,12 +89,8 @@
 
 # Once in this namespace, access to libraries in /system/lib is restricted. Only
 # libs listed here can be used.
-namespace.sphal.links = runtime,default,vndk,rs
+namespace.sphal.links = default,vndk,rs
 
-namespace.sphal.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-# LLNDK_LIBRARIES includes the runtime libs above, but the order here ensures
-# that they are loaded from the runtime namespace.
 namespace.sphal.link.default.shared_libs  = %LLNDK_LIBRARIES%
 namespace.sphal.link.default.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
 
@@ -162,11 +137,9 @@
 namespace.rs.asan.permitted.paths +=           /vendor/${LIB}
 namespace.rs.asan.permitted.paths += /data
 
-namespace.rs.links = runtime,default,vndk
+namespace.rs.links = default,vndk
 
-namespace.rs.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-namespace.rs.link.default.shared_libs  = %LLNDK_LIBRARIES%
+namespace.rs.link.default.shared_libs  =  %LLNDK_LIBRARIES%
 namespace.rs.link.default.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
 # Private LLNDK libs (e.g. libft2.so) are exceptionally allowed to this
 # namespace because RS framework libs are using them.
@@ -215,14 +188,10 @@
 # When these NDK libs are required inside this namespace, then it is redirected
 # to the default namespace. This is possible since their ABI is stable across
 # Android releases.
-namespace.vndk.links = runtime,default
-
-namespace.vndk.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
+namespace.vndk.links = default
 namespace.vndk.link.default.shared_libs  = %LLNDK_LIBRARIES%
 namespace.vndk.link.default.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
 
-
 ###############################################################################
 # Namespace config for vendor processes. In O, no restriction is enforced for
 # them. However, in O-MR1, access to /system/${LIB} will not be allowed to
@@ -230,7 +199,6 @@
 # (LL-NDK only) access.
 ###############################################################################
 [vendor]
-additional.namespaces = runtime
 namespace.default.isolated = false
 
 namespace.default.search.paths  = /odm/${LIB}
@@ -240,7 +208,7 @@
 namespace.default.search.paths += /vendor/${LIB}/vndk
 namespace.default.search.paths += /vendor/${LIB}/vndk-sp
 
-# Access to system libraries is allowed
+# Access to system libraries are allowed
 namespace.default.search.paths += /system/${LIB}/vndk%VNDK_VER%
 namespace.default.search.paths += /system/${LIB}/vndk-sp%VNDK_VER%
 namespace.default.search.paths += /system/${LIB}
@@ -270,47 +238,16 @@
 namespace.default.asan.search.paths += /data/asan/product_services/${LIB}
 namespace.default.asan.search.paths +=           /%PRODUCT_SERVICES%/${LIB}
 
-namespace.default.links = runtime
-namespace.default.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-###############################################################################
-# "runtime" APEX namespace
-#
-# This namespace pulls in externally accessible libs from the Runtime APEX.
-###############################################################################
-namespace.runtime.isolated = true
-namespace.runtime.search.paths = /apex/com.android.runtime/${LIB}
-namespace.runtime.links = default
-# TODO(b/119867084): Restrict to Bionic dlopen dependencies.
-namespace.runtime.link.default.allow_all_shared_libs = true
-
-
 ###############################################################################
 # Namespace config for binaries under /postinstall.
-# Only default and runtime namespaces are defined and default has no directories
-# other than /system/lib in the search paths. This is because linker calls
-# realpath on the search paths and this causes selinux denial if the paths
-# (/vendor, /odm) are not allowed to the postinstall binaries. There is no
-# reason to allow the binaries to access the paths.
+# Only one default namespace is defined and it has no directories other than
+# /system/lib in the search paths. This is because linker calls realpath on the
+# search paths and this causes selinux denial if the paths (/vendor, /odm) are
+# not allowed to the poinstall binaries. There is no reason to allow the
+# binaries to access the paths.
 ###############################################################################
 [postinstall]
-additional.namespaces = runtime
-
 namespace.default.isolated = false
 namespace.default.search.paths  = /system/${LIB}
 namespace.default.search.paths += /%PRODUCT%/${LIB}
 namespace.default.search.paths += /%PRODUCT_SERVICES%/${LIB}
-
-namespace.default.links = runtime
-namespace.default.link.runtime.shared_libs = libc.so:libdl.so:libm.so
-
-###############################################################################
-# "runtime" APEX namespace
-#
-# This namespace pulls in externally accessible libs from the Runtime APEX.
-###############################################################################
-namespace.runtime.isolated = true
-namespace.runtime.search.paths = /apex/com.android.runtime/${LIB}
-namespace.runtime.links = default
-# TODO(b/119867084): Restrict to Bionic dlopen dependencies.
-namespace.runtime.link.default.allow_all_shared_libs = true
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 349168e..483fc51 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -545,6 +545,7 @@
     mkdir /data/anr 0775 system system
 
     mkdir /data/apex 0770 root root
+    mkdir /data/staging 0750 system system
 
     # NFC: create data/nfc for nv storage
     mkdir /data/nfc 0770 nfc nfc
@@ -583,8 +584,8 @@
     # Set SELinux security contexts on upgrade or policy update.
     restorecon --recursive --skip-ce /data
 
-    # Check any timezone data in /data is newer than the copy in /system, delete if not.
-    exec - system system -- /system/bin/tzdatacheck /system/usr/share/zoneinfo /data/misc/zoneinfo
+    # Check any timezone data in /data is newer than the copy in the runtime module, delete if not.
+    exec - system system -- /system/bin/tzdatacheck /apex/com.android.runtime/etc/tz /data/misc/zoneinfo
 
     # If there is no post-fs-data action in the init.<device>.rc file, you
     # must uncomment this line, otherwise encrypted filesystems
diff --git a/rootdir/ueventd.rc b/rootdir/ueventd.rc
index a9658a4..35f469a 100644
--- a/rootdir/ueventd.rc
+++ b/rootdir/ueventd.rc
@@ -1,9 +1,6 @@
 firmware_directories /etc/firmware/ /odm/firmware/ /vendor/firmware/ /firmware/image/
 uevent_socket_rcvbuf_size 16M
 
-subsystem adf
-    devname uevent_devname
-
 subsystem graphics
     devname uevent_devpath
     dirname /dev/graphics
@@ -12,26 +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
@@ -59,73 +40,27 @@
 
 /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   uhid       uhid
-/dev/alarm                0664   system     radio
 /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
@@ -135,6 +70,3 @@
 /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