diff --git a/base/include/android-base/logging.h b/base/include/android-base/logging.h
index f93c696..afff2c9 100644
--- a/base/include/android-base/logging.h
+++ b/base/include/android-base/logging.h
@@ -42,6 +42,10 @@
 // By default, output goes to logcat on Android and stderr on the host.
 // A process can use `SetLogger` to decide where all logging goes.
 // Implementations are provided for logcat, stderr, and dmesg.
+//
+// By default, the process' name is used as the log tag.
+// Code can choose a specific log tag by defining LOG_TAG
+// before including this header.
 
 // This header also provides assertions:
 //
@@ -63,6 +67,16 @@
 
 #include "android-base/macros.h"
 
+// Note: DO NOT USE DIRECTLY. Use LOG_TAG instead.
+#ifdef _LOG_TAG_INTERNAL
+#error "_LOG_TAG_INTERNAL must not be defined"
+#endif
+#ifdef LOG_TAG
+#define _LOG_TAG_INTERNAL LOG_TAG
+#else
+#define _LOG_TAG_INTERNAL nullptr
+#endif
+
 namespace android {
 namespace base {
 
@@ -201,10 +215,10 @@
 
 // Get an ostream that can be used for logging at the given severity and to the
 // given destination. The same notes as for LOG_STREAM apply.
-#define LOG_STREAM_TO(dest, severity)                                   \
-  ::android::base::LogMessage(__FILE__, __LINE__,                       \
-                              ::android::base::dest,                    \
-                              SEVERITY_LAMBDA(severity), -1).stream()
+#define LOG_STREAM_TO(dest, severity)                                           \
+  ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest,        \
+                              SEVERITY_LAMBDA(severity), _LOG_TAG_INTERNAL, -1) \
+      .stream()
 
 // Logs a message to logcat on Android otherwise to stderr. If the severity is
 // FATAL it also causes an abort. For example:
@@ -231,10 +245,10 @@
 #define PLOG(severity) PLOG_TO(DEFAULT, severity)
 
 // Behaves like PLOG, but logs to the specified log ID.
-#define PLOG_TO(dest, severity)                                              \
-  LOGGING_PREAMBLE(severity) &&                                              \
-      ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest, \
-                                  SEVERITY_LAMBDA(severity), errno)          \
+#define PLOG_TO(dest, severity)                                                        \
+  LOGGING_PREAMBLE(severity) &&                                                        \
+      ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::dest,           \
+                                  SEVERITY_LAMBDA(severity), _LOG_TAG_INTERNAL, errno) \
           .stream()
 
 // Marker that code is yet to be implemented.
@@ -247,23 +261,26 @@
 //
 //     CHECK(false == true) results in a log message of
 //       "Check failed: false == true".
-#define CHECK(x)                                                                \
-  LIKELY((x)) || ABORT_AFTER_LOG_FATAL_EXPR(false) ||                           \
-      ::android::base::LogMessage(                                              \
-          __FILE__, __LINE__, ::android::base::DEFAULT, ::android::base::FATAL, \
-          -1).stream()                                                          \
+#define CHECK(x)                                                                 \
+  LIKELY((x)) || ABORT_AFTER_LOG_FATAL_EXPR(false) ||                            \
+      ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT,  \
+                                  ::android::base::FATAL, _LOG_TAG_INTERNAL, -1) \
+              .stream()                                                          \
           << "Check failed: " #x << " "
 
+// clang-format off
 // Helper for CHECK_xx(x,y) macros.
-#define CHECK_OP(LHS, RHS, OP)                                              \
-  for (auto _values = ::android::base::MakeEagerEvaluator(LHS, RHS);        \
-       UNLIKELY(!(_values.lhs OP _values.rhs));                             \
-       /* empty */)                                                         \
-  ABORT_AFTER_LOG_FATAL                                                     \
-  ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT, \
-                              ::android::base::FATAL, -1).stream()          \
-      << "Check failed: " << #LHS << " " << #OP << " " << #RHS              \
-      << " (" #LHS "=" << _values.lhs << ", " #RHS "=" << _values.rhs << ") "
+#define CHECK_OP(LHS, RHS, OP)                                                                 \
+  for (auto _values = ::android::base::MakeEagerEvaluator(LHS, RHS);                           \
+       UNLIKELY(!(_values.lhs OP _values.rhs));                                                \
+       /* empty */)                                                                            \
+  ABORT_AFTER_LOG_FATAL                                                                        \
+  ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT,                    \
+                              ::android::base::FATAL, _LOG_TAG_INTERNAL, -1)                   \
+          .stream()                                                                            \
+      << "Check failed: " << #LHS << " " << #OP << " " << #RHS << " (" #LHS "=" << _values.lhs \
+      << ", " #RHS "=" << _values.rhs << ") "
+// clang-format on
 
 // Check whether a condition holds between x and y, LOG(FATAL) if not. The value
 // of the expressions x and y is evaluated once. Extra logging can be appended
@@ -278,14 +295,17 @@
 #define CHECK_GE(x, y) CHECK_OP(x, y, >= )
 #define CHECK_GT(x, y) CHECK_OP(x, y, > )
 
+// clang-format off
 // Helper for CHECK_STRxx(s1,s2) macros.
 #define CHECK_STROP(s1, s2, sense)                                             \
   while (UNLIKELY((strcmp(s1, s2) == 0) != (sense)))                           \
     ABORT_AFTER_LOG_FATAL                                                      \
     ::android::base::LogMessage(__FILE__, __LINE__, ::android::base::DEFAULT,  \
-                                ::android::base::FATAL, -1).stream()           \
+                                ::android::base::FATAL, _LOG_TAG_INTERNAL, -1) \
+        .stream()                                                              \
         << "Check failed: " << "\"" << (s1) << "\""                            \
         << ((sense) ? " == " : " != ") << "\"" << (s2) << "\""
+// clang-format on
 
 // Check for string (const char*) equality between s1 and s2, LOG(FATAL) if not.
 #define CHECK_STREQ(s1, s2) CHECK_STROP(s1, s2, true)
@@ -400,8 +420,8 @@
 // of a CHECK. The destructor will abort if the severity is FATAL.
 class LogMessage {
  public:
-  LogMessage(const char* file, unsigned int line, LogId id,
-             LogSeverity severity, int error);
+  LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity, const char* tag,
+             int error);
 
   ~LogMessage();
 
@@ -410,12 +430,17 @@
   std::ostream& stream();
 
   // The routine that performs the actual logging.
-  static void LogLine(const char* file, unsigned int line, LogId id,
-                      LogSeverity severity, const char* msg);
+  static void LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                      const char* tag, const char* msg);
 
  private:
   const std::unique_ptr<LogMessageData> data_;
 
+  // TODO(b/35361699): remove these symbols once all prebuilds stop using it.
+  LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity, int error);
+  static void LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                      const char* msg);
+
   DISALLOW_COPY_AND_ASSIGN(LogMessage);
 };
 
diff --git a/base/logging.cpp b/base/logging.cpp
index 75078e5..0f2012a 100644
--- a/base/logging.cpp
+++ b/base/logging.cpp
@@ -187,8 +187,8 @@
 }
 #endif
 
-void StderrLogger(LogId, LogSeverity severity, const char*, const char* file,
-                  unsigned int line, const char* message) {
+void StderrLogger(LogId, LogSeverity severity, const char* tag, const char* file, unsigned int line,
+                  const char* message) {
   struct tm now;
   time_t t = time(nullptr);
 
@@ -205,8 +205,8 @@
   static_assert(arraysize(log_characters) - 1 == FATAL + 1,
                 "Mismatch in size of log_characters and values in LogSeverity");
   char severity_char = log_characters[severity];
-  fprintf(stderr, "%s %c %s %5d %5d %s:%u] %s\n", ProgramInvocationName().c_str(),
-          severity_char, timestamp, getpid(), GetThreadId(), file, line, message);
+  fprintf(stderr, "%s %c %s %5d %5d %s:%u] %s\n", tag ? tag : "nullptr", severity_char, timestamp,
+          getpid(), GetThreadId(), file, line, message);
 }
 
 void DefaultAborter(const char* abort_message) {
@@ -344,14 +344,14 @@
 // checks/logging in a function.
 class LogMessageData {
  public:
-  LogMessageData(const char* file, unsigned int line, LogId id,
-                 LogSeverity severity, int error)
+  LogMessageData(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                 const char* tag, int error)
       : file_(GetFileBasename(file)),
         line_number_(line),
         id_(id),
         severity_(severity),
-        error_(error) {
-  }
+        tag_(tag),
+        error_(error) {}
 
   const char* GetFile() const {
     return file_;
@@ -365,6 +365,8 @@
     return severity_;
   }
 
+  const char* GetTag() const { return tag_; }
+
   LogId GetId() const {
     return id_;
   }
@@ -387,15 +389,19 @@
   const unsigned int line_number_;
   const LogId id_;
   const LogSeverity severity_;
+  const char* const tag_;
   const int error_;
 
   DISALLOW_COPY_AND_ASSIGN(LogMessageData);
 };
 
-LogMessage::LogMessage(const char* file, unsigned int line, LogId id,
-                       LogSeverity severity, int error)
-    : data_(new LogMessageData(file, line, id, severity, error)) {
-}
+LogMessage::LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                       const char* tag, int error)
+    : data_(new LogMessageData(file, line, id, severity, tag, error)) {}
+
+LogMessage::LogMessage(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                       int error)
+    : LogMessage(file, line, id, severity, nullptr, error) {}
 
 LogMessage::~LogMessage() {
   // Check severity again. This is duplicate work wrt/ LOG macros, but not LOG_STREAM.
@@ -413,16 +419,16 @@
     // Do the actual logging with the lock held.
     std::lock_guard<std::mutex> lock(LoggingLock());
     if (msg.find('\n') == std::string::npos) {
-      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
-              data_->GetSeverity(), msg.c_str());
+      LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(), data_->GetSeverity(),
+              data_->GetTag(), msg.c_str());
     } else {
       msg += '\n';
       size_t i = 0;
       while (i < msg.size()) {
         size_t nl = msg.find('\n', i);
         msg[nl] = '\0';
-        LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(),
-                data_->GetSeverity(), &msg[i]);
+        LogLine(data_->GetFile(), data_->GetLineNumber(), data_->GetId(), data_->GetSeverity(),
+                data_->GetTag(), &msg[i]);
         // Undo the zero-termination so we can give the complete message to the aborter.
         msg[nl] = '\n';
         i = nl + 1;
@@ -440,12 +446,17 @@
   return data_->GetBuffer();
 }
 
-void LogMessage::LogLine(const char* file, unsigned int line, LogId id,
-                         LogSeverity severity, const char* message) {
-  const char* tag = ProgramInvocationName().c_str();
+void LogMessage::LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                         const char* tag, const char* message) {
+  if (tag == nullptr) tag = ProgramInvocationName().c_str();
   Logger()(id, severity, tag, file, line, message);
 }
 
+void LogMessage::LogLine(const char* file, unsigned int line, LogId id, LogSeverity severity,
+                         const char* message) {
+  LogLine(file, line, id, severity, nullptr, message);
+}
+
 LogSeverity GetMinimumLogSeverity() {
     return gMinimumLogSeverity;
 }
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index fad899f..133f3b9 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -215,6 +215,15 @@
     ],
 }
 
+cc_binary {
+    name: "unwind_for_offline",
+    defaults: ["libunwindstack_tools"],
+
+    srcs: [
+        "tools/unwind_for_offline.cpp",
+    ],
+}
+
 // Generates the elf data for use in the tests for .gnu_debugdata frames.
 // Once these files are generated, use the xz command to compress the data.
 cc_binary_host {
diff --git a/libunwindstack/Memory.cpp b/libunwindstack/Memory.cpp
index 1f3c6c3..285f879 100644
--- a/libunwindstack/Memory.cpp
+++ b/libunwindstack/Memory.cpp
@@ -35,10 +35,6 @@
 namespace unwindstack {
 
 static size_t ProcessVmRead(pid_t pid, uint64_t remote_src, void* dst, size_t len) {
-  struct iovec dst_iov = {
-      .iov_base = dst,
-      .iov_len = len,
-  };
 
   // Split up the remote read across page boundaries.
   // From the manpage:
@@ -49,39 +45,49 @@
   //   perform a partial transfer that splits a single iovec element.
   constexpr size_t kMaxIovecs = 64;
   struct iovec src_iovs[kMaxIovecs];
-  size_t iovecs_used = 0;
 
   uint64_t cur = remote_src;
+  size_t total_read = 0;
   while (len > 0) {
-    if (iovecs_used == kMaxIovecs) {
-      errno = EINVAL;
-      return 0;
+    struct iovec dst_iov = {
+        .iov_base = &reinterpret_cast<uint8_t*>(dst)[total_read], .iov_len = len,
+    };
+
+    size_t iovecs_used = 0;
+    while (len > 0) {
+      if (iovecs_used == kMaxIovecs) {
+        break;
+      }
+
+      // struct iovec uses void* for iov_base.
+      if (cur >= UINTPTR_MAX) {
+        errno = EFAULT;
+        return total_read;
+      }
+
+      src_iovs[iovecs_used].iov_base = reinterpret_cast<void*>(cur);
+
+      uintptr_t misalignment = cur & (getpagesize() - 1);
+      size_t iov_len = getpagesize() - misalignment;
+      iov_len = std::min(iov_len, len);
+
+      len -= iov_len;
+      if (__builtin_add_overflow(cur, iov_len, &cur)) {
+        errno = EFAULT;
+        return total_read;
+      }
+
+      src_iovs[iovecs_used].iov_len = iov_len;
+      ++iovecs_used;
     }
 
-    // struct iovec uses void* for iov_base.
-    if (cur >= UINTPTR_MAX) {
-      errno = EFAULT;
-      return 0;
+    ssize_t rc = process_vm_readv(pid, &dst_iov, 1, src_iovs, iovecs_used, 0);
+    if (rc == -1) {
+      return total_read;
     }
-
-    src_iovs[iovecs_used].iov_base = reinterpret_cast<void*>(cur);
-
-    uintptr_t misalignment = cur & (getpagesize() - 1);
-    size_t iov_len = getpagesize() - misalignment;
-    iov_len = std::min(iov_len, len);
-
-    len -= iov_len;
-    if (__builtin_add_overflow(cur, iov_len, &cur)) {
-      errno = EFAULT;
-      return 0;
-    }
-
-    src_iovs[iovecs_used].iov_len = iov_len;
-    ++iovecs_used;
+    total_read += rc;
   }
-
-  ssize_t rc = process_vm_readv(pid, &dst_iov, 1, src_iovs, iovecs_used, 0);
-  return rc == -1 ? 0 : rc;
+  return total_read;
 }
 
 static bool PtraceReadLong(pid_t pid, uint64_t addr, long* value) {
diff --git a/libunwindstack/tests/MemoryRemoteTest.cpp b/libunwindstack/tests/MemoryRemoteTest.cpp
index f5492a2..fb56e8a 100644
--- a/libunwindstack/tests/MemoryRemoteTest.cpp
+++ b/libunwindstack/tests/MemoryRemoteTest.cpp
@@ -79,6 +79,35 @@
   ASSERT_TRUE(Detach(pid));
 }
 
+TEST_F(MemoryRemoteTest, read_large) {
+  static constexpr size_t kTotalPages = 245;
+  std::vector<uint8_t> src(kTotalPages * getpagesize());
+  for (size_t i = 0; i < kTotalPages; i++) {
+    memset(&src[i * getpagesize()], i, getpagesize());
+  }
+
+  pid_t pid;
+  if ((pid = fork()) == 0) {
+    while (true)
+      ;
+    exit(1);
+  }
+  ASSERT_LT(0, pid);
+  TestScopedPidReaper reap(pid);
+
+  ASSERT_TRUE(Attach(pid));
+
+  MemoryRemote remote(pid);
+
+  std::vector<uint8_t> dst(kTotalPages * getpagesize());
+  ASSERT_TRUE(remote.ReadFully(reinterpret_cast<uint64_t>(src.data()), dst.data(), src.size()));
+  for (size_t i = 0; i < kTotalPages * getpagesize(); i++) {
+    ASSERT_EQ(i / getpagesize(), dst[i]) << "Failed at byte " << i;
+  }
+
+  ASSERT_TRUE(Detach(pid));
+}
+
 TEST_F(MemoryRemoteTest, read_partial) {
   char* mapping = static_cast<char*>(
       mmap(nullptr, 4 * getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
diff --git a/libunwindstack/tools/unwind_for_offline.cpp b/libunwindstack/tools/unwind_for_offline.cpp
new file mode 100644
index 0000000..d64ef8f
--- /dev/null
+++ b/libunwindstack/tools/unwind_for_offline.cpp
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#define _GNU_SOURCE 1
+#include <errno.h>
+#include <inttypes.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include <unwindstack/Elf.h>
+#include <unwindstack/Maps.h>
+#include <unwindstack/Memory.h>
+#include <unwindstack/Regs.h>
+#include <unwindstack/Unwinder.h>
+
+#include <android-base/stringprintf.h>
+
+struct map_info_t {
+  uint64_t start;
+  uint64_t end;
+  uint64_t offset;
+  std::string name;
+};
+
+static bool Attach(pid_t pid) {
+  if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
+    return false;
+  }
+
+  // Allow at least 1 second to attach properly.
+  for (size_t i = 0; i < 1000; i++) {
+    siginfo_t si;
+    if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si) == 0) {
+      return true;
+    }
+    usleep(1000);
+  }
+  printf("%d: Failed to stop.\n", pid);
+  return false;
+}
+
+bool SaveRegs(unwindstack::Regs* regs) {
+  std::unique_ptr<FILE, decltype(&fclose)> fp(fopen("regs.txt", "w+"), &fclose);
+  if (fp == nullptr) {
+    printf("Failed to create file regs.txt.\n");
+    return false;
+  }
+  regs->IterateRegisters([&fp](const char* name, uint64_t value) {
+    fprintf(fp.get(), "%s: %" PRIx64 "\n", name, value);
+  });
+
+  return true;
+}
+
+bool SaveStack(pid_t pid, uint64_t sp_start, uint64_t sp_end) {
+  std::unique_ptr<FILE, decltype(&fclose)> fp(fopen("stack.data", "w+"), &fclose);
+  if (fp == nullptr) {
+    printf("Failed to create stack.data.\n");
+    return false;
+  }
+
+  size_t bytes = fwrite(&sp_start, 1, sizeof(sp_start), fp.get());
+  if (bytes != sizeof(sp_start)) {
+    perror("Failed to write all data.");
+    return false;
+  }
+
+  std::vector<uint8_t> buffer(sp_end - sp_start);
+  auto process_memory = unwindstack::Memory::CreateProcessMemory(pid);
+  if (!process_memory->Read(sp_start, buffer.data(), buffer.size())) {
+    printf("Unable to read stack data.\n");
+    return false;
+  }
+
+  bytes = fwrite(buffer.data(), 1, buffer.size(), fp.get());
+  if (bytes != buffer.size()) {
+    printf("Failed to write all stack data: stack size %zu, written %zu\n", buffer.size(), bytes);
+    return 1;
+  }
+
+  return true;
+}
+
+bool CreateElfFromMemory(std::shared_ptr<unwindstack::Memory>& memory, map_info_t* info) {
+  std::string cur_name;
+  if (info->name.empty()) {
+    cur_name = android::base::StringPrintf("anonymous:%" PRIx64, info->start);
+  } else {
+    cur_name = basename(info->name.c_str());
+    cur_name = android::base::StringPrintf("%s:%" PRIx64, basename(info->name.c_str()), info->start);
+  }
+
+  std::unique_ptr<FILE, decltype(&fclose)> output(fopen(cur_name.c_str(), "w+"), &fclose);
+  if (output == nullptr) {
+    printf("Cannot create %s\n", cur_name.c_str());
+    return false;
+  }
+  std::vector<uint8_t> buffer(info->end - info->start);
+  // If this is a mapped in file, it might not be possible to read the entire
+  // map, so read all that is readable.
+  size_t bytes = memory->Read(info->start, buffer.data(), buffer.size());
+  if (bytes == 0) {
+    printf("Cannot read data from address %" PRIx64 " length %zu\n", info->start, buffer.size());
+    return false;
+  }
+  size_t bytes_written = fwrite(buffer.data(), 1, bytes, output.get());
+  if (bytes_written != bytes) {
+    printf("Failed to write all data to file: bytes read %zu, written %zu\n", bytes, bytes_written);
+    return false;
+  }
+
+  // Replace the name with the new name.
+  info->name = cur_name;
+
+  return true;
+}
+
+bool CopyElfFromFile(map_info_t* info) {
+  std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(info->name.c_str(), "r"), &fclose);
+  if (fp == nullptr) {
+    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) {
+    printf("Cannot create file %s\n", cur_name.c_str());
+    return false;
+  }
+  std::vector<uint8_t> buffer(10000);
+  size_t bytes;
+  while ((bytes = fread(buffer.data(), 1, buffer.size(), fp.get())) > 0) {
+    size_t bytes_written = fwrite(buffer.data(), 1, bytes, output.get());
+    if (bytes_written != bytes) {
+      printf("Bytes written doesn't match bytes read: read %zu, written %zu\n", bytes,
+             bytes_written);
+      return false;
+    }
+  }
+
+  // Replace the name with the new name.
+  info->name = cur_name;
+
+  return true;
+}
+
+int SaveData(pid_t pid) {
+  unwindstack::Regs* regs = unwindstack::Regs::RemoteGet(pid);
+  if (regs == nullptr) {
+    printf("Unable to get remote reg data.\n");
+    return 1;
+  }
+
+  unwindstack::RemoteMaps maps(pid);
+  if (!maps.Parse()) {
+    printf("Unable to parse maps.\n");
+    return 1;
+  }
+
+  // Save the current state of the registers.
+  if (!SaveRegs(regs)) {
+    return 1;
+  }
+
+  // Do an unwind so we know how much of the stack to save, and what
+  // elf files are involved.
+  uint64_t sp = regs->sp();
+  auto process_memory = unwindstack::Memory::CreateProcessMemory(pid);
+  unwindstack::Unwinder unwinder(1024, &maps, regs, process_memory);
+  unwinder.Unwind();
+
+  std::unordered_map<uint64_t, map_info_t> maps_by_start;
+  uint64_t last_sp;
+  for (auto frame : unwinder.frames()) {
+    last_sp = frame.sp;
+    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)) {
+          return 1;
+        }
+      }
+    }
+  }
+
+  if (!SaveStack(pid, sp, last_sp)) {
+    return 1;
+  }
+
+  std::vector<std::pair<uint64_t, map_info_t>> sorted_maps(maps_by_start.begin(),
+                                                           maps_by_start.end());
+  std::sort(sorted_maps.begin(), sorted_maps.end(),
+            [](auto& a, auto& b) { return a.first < b.first; });
+
+  std::unique_ptr<FILE, decltype(&fclose)> fp(fopen("maps.txt", "w+"), &fclose);
+  if (fp == nullptr) {
+    printf("Failed to create maps.txt.\n");
+    return false;
+  }
+
+  for (auto& element : sorted_maps) {
+    map_info_t& map = element.second;
+    fprintf(fp.get(), "%" PRIx64 "-%" PRIx64 " r-xp %" PRIx64 " 00:00 0", map.start, map.end,
+            map.offset);
+    if (!map.name.empty()) {
+      fprintf(fp.get(), "   %s", map.name.c_str());
+    }
+    fprintf(fp.get(), "\n");
+  }
+
+  return 0;
+}
+
+int main(int argc, char** argv) {
+  if (argc != 2) {
+    printf("Usage: unwind_for_offline <PID>\n");
+    return 1;
+  }
+
+  pid_t pid = atoi(argv[1]);
+  if (!Attach(pid)) {
+    printf("Failed to attach to pid %d: %s\n", pid, strerror(errno));
+    return 1;
+  }
+
+  int return_code = SaveData(pid);
+
+  ptrace(PTRACE_DETACH, pid, 0, 0);
+
+  return return_code;
+}
diff --git a/libusbhost/include/usbhost/usbhost.h b/libusbhost/include/usbhost/usbhost.h
index a8dd673..9758b18 100644
--- a/libusbhost/include/usbhost/usbhost.h
+++ b/libusbhost/include/usbhost/usbhost.h
@@ -140,8 +140,26 @@
 const struct usb_device_descriptor* usb_device_get_device_descriptor(struct usb_device *device);
 
 /* Returns a USB descriptor string for the given string ID.
+ * Return value: < 0 on error.  0 on success.
+ * The string is returned in ucs2_out in USB-native UCS-2 encoding.
+ *
+ * parameters:
+ *  id - the string descriptor index.
+ *  timeout - in milliseconds (see Documentation/driver-api/usb/usb.rst)
+ *  ucs2_out - Must point to null on call.
+ *             Will be filled in with a buffer on success.
+ *             If this is non-null on return, it must be free()d.
+ *  response_size - size, in bytes, of ucs-2 string in ucs2_out.
+ *                  The size isn't guaranteed to include null termination.
+ * Call free() to free the result when you are done with it.
+ */
+int usb_device_get_string_ucs2(struct usb_device* device, int id, int timeout, void** ucs2_out,
+                               size_t* response_size);
+
+/* Returns a USB descriptor string for the given string ID.
  * Used to implement usb_device_get_manufacturer_name,
  * usb_device_get_product_name and usb_device_get_serial.
+ * Returns ascii - non ascii characters will be replaced with '?'.
  * Call free() to free the result when you are done with it.
  */
 char* usb_device_get_string(struct usb_device *device, int id, int timeout);
diff --git a/libusbhost/usbhost.c b/libusbhost/usbhost.c
index 4d286bf..fa0191b 100644
--- a/libusbhost/usbhost.c
+++ b/libusbhost/usbhost.c
@@ -464,17 +464,30 @@
     return (struct usb_device_descriptor*)device->desc;
 }
 
-char* usb_device_get_string(struct usb_device *device, int id, int timeout)
-{
-    char string[256];
-    __u16 buffer[MAX_STRING_DESCRIPTOR_LENGTH / sizeof(__u16)];
+/* Returns a USB descriptor string for the given string ID.
+ * Return value: < 0 on error.  0 on success.
+ * The string is returned in ucs2_out in USB-native UCS-2 encoding.
+ *
+ * parameters:
+ *  id - the string descriptor index.
+ *  timeout - in milliseconds (see Documentation/driver-api/usb/usb.rst)
+ *  ucs2_out - Must point to null on call.
+ *             Will be filled in with a buffer on success.
+ *             If this is non-null on return, it must be free()d.
+ *  response_size - size, in bytes, of ucs-2 string in ucs2_out.
+ *                  The size isn't guaranteed to include null termination.
+ * Call free() to free the result when you are done with it.
+ */
+int usb_device_get_string_ucs2(struct usb_device* device, int id, int timeout, void** ucs2_out,
+                               size_t* response_size) {
     __u16 languages[MAX_STRING_DESCRIPTOR_LENGTH / sizeof(__u16)];
-    int i, result;
+    char response[MAX_STRING_DESCRIPTOR_LENGTH];
+    int result;
     int languageCount = 0;
 
-    if (id == 0) return NULL;
+    if (id == 0) return -1;
+    if (*ucs2_out != NULL) return -1;
 
-    string[0] = 0;
     memset(languages, 0, sizeof(languages));
 
     // read list of supported languages
@@ -485,25 +498,54 @@
     if (result > 0)
         languageCount = (result - 2) / 2;
 
-    for (i = 1; i <= languageCount; i++) {
-        memset(buffer, 0, sizeof(buffer));
+    for (int i = 1; i <= languageCount; i++) {
+        memset(response, 0, sizeof(response));
 
-        result = usb_device_control_transfer(device,
-                USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE, USB_REQ_GET_DESCRIPTOR,
-                (USB_DT_STRING << 8) | id, languages[i], buffer, sizeof(buffer),
-                timeout);
-        if (result > 0) {
-            int i;
-            // skip first word, and copy the rest to the string, changing shorts to bytes.
-            result /= 2;
-            for (i = 1; i < result; i++)
-                string[i - 1] = buffer[i];
-            string[i - 1] = 0;
-            return strdup(string);
+        result = usb_device_control_transfer(
+            device, USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE, USB_REQ_GET_DESCRIPTOR,
+            (USB_DT_STRING << 8) | id, languages[i], response, sizeof(response), timeout);
+        if (result >= 2) {  // string contents begin at offset 2.
+            int descriptor_len = result - 2;
+            char* out = malloc(descriptor_len + 3);
+            if (out == NULL) {
+                return -1;
+            }
+            memcpy(out, response + 2, descriptor_len);
+            // trail with three additional NULLs, so that there's guaranteed
+            // to be a UCS-2 NULL character beyond whatever USB returned.
+            // The returned string length is still just what USB returned.
+            memset(out + descriptor_len, '\0', 3);
+            *ucs2_out = (void*)out;
+            *response_size = descriptor_len;
+            return 0;
         }
     }
+    return -1;
+}
 
-    return NULL;
+/* Warning: previously this blindly returned the lower 8 bits of
+ * every UCS-2 character in a USB descriptor.  Now it will replace
+ * values > 127 with ascii '?'.
+ */
+char* usb_device_get_string(struct usb_device* device, int id, int timeout) {
+    char* ascii_string = NULL;
+    size_t raw_string_len = 0;
+    size_t i;
+    if (usb_device_get_string_ucs2(device, id, timeout, (void**)&ascii_string, &raw_string_len) < 0)
+        return NULL;
+    if (ascii_string == NULL) return NULL;
+    for (i = 0; i < raw_string_len / 2; ++i) {
+        // wire format for USB is always little-endian.
+        char lower = ascii_string[2 * i];
+        char upper = ascii_string[2 * i + 1];
+        if (upper || (lower & 0x80)) {
+            ascii_string[i] = '?';
+        } else {
+            ascii_string[i] = lower;
+        }
+    }
+    ascii_string[i] = '\0';
+    return ascii_string;
 }
 
 char* usb_device_get_manufacturer_name(struct usb_device *device, int timeout)
diff --git a/rootdir/etc/ld.config.txt.in b/rootdir/etc/ld.config.txt.in
index df26f90..7036356 100644
--- a/rootdir/etc/ld.config.txt.in
+++ b/rootdir/etc/ld.config.txt.in
@@ -218,7 +218,7 @@
 # (LL-NDK only) access.
 ###############################################################################
 [vendor]
-additional.namespaces = system
+additional.namespaces = system,vndk
 
 ###############################################################################
 # "default" namespace
@@ -261,10 +261,39 @@
 namespace.default.asan.permitted.paths += /data/asan/vendor
 namespace.default.asan.permitted.paths +=           /vendor
 
-namespace.default.links = system
-namespace.default.link.system.shared_libs  = %LLNDK_LIBRARIES%
-namespace.default.link.system.shared_libs += %VNDK_SAMEPROCESS_LIBRARIES%
-namespace.default.link.system.shared_libs += %VNDK_CORE_LIBRARIES%
+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%
+
+###############################################################################
+# "vndk" namespace
+#
+# This namespace is where VNDK and VNDK-SP libraries are loaded for
+# a vendor process.
+###############################################################################
+namespace.vndk.isolated = false
+
+namespace.vndk.search.paths  = /system/${LIB}/vndk-sp${VNDK_VER}
+namespace.vndk.search.paths += /system/${LIB}/vndk${VNDK_VER}
+
+# This is exceptionally required since android.hidl.memory@1.0-impl.so is here
+namespace.vndk.permitted.paths = /system/${LIB}/vndk-sp${VNDK_VER}/hw
+
+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
+
+namespace.vndk.asan.search.paths  = /data/asan/system/${LIB}/vndk-sp${VNDK_VER}
+namespace.vndk.asan.search.paths +=           /system/${LIB}/vndk-sp${VNDK_VER}
+namespace.vndk.asan.search.paths += /data/asan/system/${LIB}/vndk${VNDK_VER}
+namespace.vndk.asan.search.paths +=           /system/${LIB}/vndk${VNDK_VER}
+
+# 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 = system
+namespace.vndk.link.system.shared_libs  = %LLNDK_LIBRARIES%
+namespace.vndk.link.system.shared_libs += %SANITIZER_RUNTIME_LIBRARIES%
 
 ###############################################################################
 # "system" namespace
@@ -274,13 +303,7 @@
 ###############################################################################
 namespace.system.isolated = false
 
-namespace.system.search.paths  = /system/${LIB}/vndk-sp${VNDK_VER}
-namespace.system.search.paths += /system/${LIB}/vndk${VNDK_VER}
-namespace.system.search.paths += /system/${LIB}
+namespace.system.search.paths = /system/${LIB}
 
-namespace.system.asan.search.paths  = /data/asan/system/${LIB}/vndk-sp${VNDK_VER}
-namespace.system.asan.search.paths +=           /system/${LIB}/vndk-sp${VNDK_VER}
-namespace.system.asan.search.paths += /data/asan/system/${LIB}/vndk${VNDK_VER}
-namespace.system.asan.search.paths +=           /system/${LIB}/vndk${VNDK_VER}
-namespace.system.asan.search.paths += /data/asan/system/${LIB}
+namespace.system.asan.search.paths  = /data/asan/system/${LIB}
 namespace.system.asan.search.paths +=           /system/${LIB}