diff --git a/adb/file_sync_service.cpp b/adb/file_sync_service.cpp
index c6f3e66..9a87931 100644
--- a/adb/file_sync_service.cpp
+++ b/adb/file_sync_service.cpp
@@ -62,7 +62,7 @@
     }
 
     vfs_cap_data cap_data = {};
-    cap_data.magic_etc = VFS_CAP_REVISION | VFS_CAP_FLAGS_EFFECTIVE;
+    cap_data.magic_etc = VFS_CAP_REVISION_2 | VFS_CAP_FLAGS_EFFECTIVE;
     cap_data.data[0].permitted = (capabilities & 0xffffffff);
     cap_data.data[0].inheritable = 0;
     cap_data.data[1].permitted = (capabilities >> 32);
diff --git a/adb/sysdeps.h b/adb/sysdeps.h
index 0abb680..307be6d 100644
--- a/adb/sysdeps.h
+++ b/adb/sysdeps.h
@@ -31,6 +31,7 @@
 
 // Include this before open/close/unlink are defined as macros below.
 #include <android-base/errors.h>
+#include <android-base/macros.h>
 #include <android-base/unique_fd.h>
 #include <android-base/utf8.h>
 
@@ -38,21 +39,6 @@
 #include "sysdeps/network.h"
 #include "sysdeps/stat.h"
 
-/*
- * TEMP_FAILURE_RETRY is defined by some, but not all, versions of
- * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
- * not already defined, then define it here.
- */
-#ifndef TEMP_FAILURE_RETRY
-/* Used to retry syscalls that can return EINTR. */
-#define TEMP_FAILURE_RETRY(exp) ({         \
-    typeof (exp) _rc;                      \
-    do {                                   \
-        _rc = (exp);                       \
-    } while (_rc == -1 && errno == EINTR); \
-    _rc; })
-#endif
-
 // Some printf-like functions are implemented in terms of
 // android::base::StringAppendV, so they should use the same attribute for
 // compile-time format string checking. On Windows, if the mingw version of
diff --git a/bootstat/bootstat.cpp b/bootstat/bootstat.cpp
index 8c11289..05474ef 100644
--- a/bootstat/bootstat.cpp
+++ b/bootstat/bootstat.cpp
@@ -228,6 +228,13 @@
     {"reboot,its_just_so_hard", 88},  // produced by boot_reason_test
     {"reboot,Its Just So Hard", 89},  // produced by boot_reason_test
     {"usb", 90},
+    {"charge", 91},
+    {"oem_tz_crash", 92},
+    {"uvlo", 93},
+    {"oem_ps_hold", 94},
+    {"abnormal_reset", 95},
+    {"oemerr_unknown", 96},
+    {"reboot_fastboot_mode", 97},
 };
 
 // Converts a string value representing the reason the system booted to an
diff --git a/fastboot/Android.mk b/fastboot/Android.mk
index 7723ec6..b0b2337 100644
--- a/fastboot/Android.mk
+++ b/fastboot/Android.mk
@@ -39,7 +39,7 @@
 LOCAL_MODULE_TAGS := debug
 LOCAL_MODULE_HOST_OS := darwin linux windows
 LOCAL_CFLAGS += -Wall -Wextra -Werror -Wunreachable-code
-LOCAL_REQUIRED_MODULES := mke2fs e2fsdroid
+LOCAL_REQUIRED_MODULES := mke2fs e2fsdroid make_f2fs
 
 LOCAL_SRC_FILES_linux := usb_linux.cpp
 LOCAL_STATIC_LIBRARIES_linux := libselinux
@@ -66,8 +66,6 @@
     libcutils \
     libgtest_host \
 
-LOCAL_CFLAGS_linux := -DUSE_F2FS
-
 LOCAL_CXX_STL := libc++_static
 
 # Don't add anything here, we don't want additional shared dependencies
@@ -80,6 +78,7 @@
 my_dist_files := $(LOCAL_BUILT_MODULE)
 my_dist_files += $(HOST_OUT_EXECUTABLES)/mke2fs$(HOST_EXECUTABLE_SUFFIX)
 my_dist_files += $(HOST_OUT_EXECUTABLES)/e2fsdroid$(HOST_EXECUTABLE_SUFFIX)
+my_dist_files += $(HOST_OUT_EXECUTABLES)/make_f2fs$(HOST_EXECUTABLE_SUFFIX)
 $(call dist-for-goals,dist_files sdk win_sdk,$(my_dist_files))
 ifdef HOST_CROSS_OS
 # Archive fastboot.exe for win_sdk build.
diff --git a/fastboot/fs.cpp b/fastboot/fs.cpp
index 8877b09..4141a3b 100644
--- a/fastboot/fs.cpp
+++ b/fastboot/fs.cpp
@@ -154,10 +154,10 @@
     return 0;
 }
 
-#ifdef USE_F2FS
 static int generate_f2fs_image(const char* fileName, long long partSize, const std::string& initial_dir,
                                unsigned /* unused */, unsigned /* unused */)
 {
+#ifndef WIN32
     const std::string exec_dir = android::base::GetExecutableDirectory();
     const std::string mkf2fs_path = exec_dir + "/make_f2fs";
     std::vector<const char*> mkf2fs_args = {mkf2fs_path.c_str()};
@@ -180,12 +180,15 @@
     }
 
     if (!initial_dir.empty()) {
-        fprintf(stderr, "Unable to set initial directory on F2FS filesystem: %s\n", strerror(errno));
-        return -1;
+        fprintf(stderr, "sload.f2s not supported yet\n");
+        return 0;
     }
     return 0;
-}
+#else
+    fprintf(stderr, "make_f2fs not supported on Windows\n");
+    return -1;
 #endif
+}
 
 static const struct fs_generator {
     const char* fs_type;  //must match what fastboot reports for partition type
@@ -196,9 +199,7 @@
 
 } generators[] = {
     { "ext4", generate_ext4_image},
-#ifdef USE_F2FS
     { "f2fs", generate_f2fs_image},
-#endif
 };
 
 const struct fs_generator* fs_get_generator(const std::string& fs_type) {
diff --git a/init/capabilities.cpp b/init/capabilities.cpp
index 642a364..50987db 100644
--- a/init/capabilities.cpp
+++ b/init/capabilities.cpp
@@ -194,5 +194,18 @@
     return SetAmbientCaps(to_keep);
 }
 
+bool DropInheritableCaps() {
+    ScopedCaps caps(cap_get_proc());
+    if (cap_clear_flag(caps.get(), CAP_INHERITABLE) == -1) {
+        PLOG(ERROR) << "cap_clear_flag(INHERITABLE) failed";
+        return false;
+    }
+    if (cap_set_proc(caps.get()) != 0) {
+        PLOG(ERROR) << "cap_set_proc() failed";
+        return false;
+    }
+    return true;
+}
+
 }  // namespace init
 }  // namespace android
diff --git a/init/capabilities.h b/init/capabilities.h
index ede85c3..fc80c98 100644
--- a/init/capabilities.h
+++ b/init/capabilities.h
@@ -35,6 +35,7 @@
 bool CapAmbientSupported();
 unsigned int GetLastValidCap();
 bool SetCapsForExec(const CapSet& to_keep);
+bool DropInheritableCaps();
 
 }  // namespace init
 }  // namespace android
diff --git a/init/service.cpp b/init/service.cpp
index 481df65..331b859 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -291,6 +291,11 @@
         if (!SetCapsForExec(capabilities_)) {
             LOG(FATAL) << "cannot set capabilities for " << name_;
         }
+    } else if (uid_) {
+        // Inheritable caps can be non-zero when running in a container.
+        if (!DropInheritableCaps()) {
+            LOG(FATAL) << "cannot drop inheritable caps for " << name_;
+        }
     }
 }
 
diff --git a/init/subcontext.cpp b/init/subcontext.cpp
index 84feeee..068be6e 100644
--- a/init/subcontext.cpp
+++ b/init/subcontext.cpp
@@ -23,7 +23,6 @@
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
-#include <android-base/properties.h>
 #include <android-base/strings.h>
 #include <selinux/android.h>
 
@@ -32,7 +31,6 @@
 #include "system/core/init/subcontext.pb.h"
 #include "util.h"
 
-using android::base::GetBoolProperty;
 using android::base::GetExecutablePath;
 using android::base::Join;
 using android::base::Socketpair;
@@ -262,13 +260,11 @@
 static std::vector<Subcontext> subcontexts;
 
 std::vector<Subcontext>* InitializeSubcontexts() {
-    if (GetBoolProperty("ro.init.subcontexts_enabled", false)) {
-        static const char* const paths_and_secontexts[][2] = {
-            {"/vendor", kVendorContext.c_str()},
-        };
-        for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
-            subcontexts.emplace_back(path_prefix, secontext);
-        }
+    static const char* const paths_and_secontexts[][2] = {
+        {"/vendor", kVendorContext.c_str()},
+    };
+    for (const auto& [path_prefix, secontext] : paths_and_secontexts) {
+        subcontexts.emplace_back(path_prefix, secontext);
     }
     return &subcontexts;
 }
diff --git a/libbacktrace/UnwindStackMap.cpp b/libbacktrace/UnwindStackMap.cpp
index 25e5002..9ac0a0b 100644
--- a/libbacktrace/UnwindStackMap.cpp
+++ b/libbacktrace/UnwindStackMap.cpp
@@ -44,15 +44,15 @@
   }
 
   // Iterate through the maps and fill in the backtrace_map_t structure.
-  for (auto& map_info : *stack_maps_) {
+  for (auto* map_info : *stack_maps_) {
     backtrace_map_t map;
-    map.start = map_info.start;
-    map.end = map_info.end;
-    map.offset = map_info.offset;
+    map.start = map_info->start;
+    map.end = map_info->end;
+    map.offset = map_info->offset;
     // Set to -1 so that it is demand loaded.
     map.load_bias = static_cast<uintptr_t>(-1);
-    map.flags = map_info.flags;
-    map.name = map_info.name;
+    map.flags = map_info->flags;
+    map.name = map_info->name;
 
     maps_.push_back(map);
   }
diff --git a/libbacktrace/backtrace_test.cpp b/libbacktrace/backtrace_test.cpp
index 0a60ec4..9911e74 100644
--- a/libbacktrace/backtrace_test.cpp
+++ b/libbacktrace/backtrace_test.cpp
@@ -77,6 +77,7 @@
 
 struct dump_thread_t {
   thread_t thread;
+  BacktraceMap* map;
   Backtrace* backtrace;
   int32_t* now;
   int32_t done;
@@ -632,7 +633,7 @@
   }
 
   // The status of the actual unwind will be checked elsewhere.
-  dump->backtrace = Backtrace::Create(getpid(), dump->thread.tid);
+  dump->backtrace = Backtrace::Create(getpid(), dump->thread.tid, dump->map);
   dump->backtrace->Unwind(0);
 
   android_atomic_acquire_store(1, &dump->done);
@@ -640,8 +641,8 @@
   return nullptr;
 }
 
-TEST(libbacktrace, thread_multiple_dump) {
-  // Dump NUM_THREADS simultaneously.
+static void MultipleThreadDumpTest(bool share_map) {
+  // Dump NUM_THREADS simultaneously using the same map.
   std::vector<thread_t> runners(NUM_THREADS);
   std::vector<dump_thread_t> dumpers(NUM_THREADS);
 
@@ -662,12 +663,17 @@
 
   // Start all of the dumpers at once, they will spin until they are signalled
   // to begin their dump run.
+  std::unique_ptr<BacktraceMap> map;
+  if (share_map) {
+    map.reset(BacktraceMap::Create(getpid()));
+  }
   int32_t dump_now = 0;
   for (size_t i = 0; i < NUM_THREADS; i++) {
     dumpers[i].thread.tid = runners[i].tid;
     dumpers[i].thread.state = 0;
     dumpers[i].done = 0;
     dumpers[i].now = &dump_now;
+    dumpers[i].map = map.get();
 
     ASSERT_TRUE(pthread_create(&dumpers[i].thread.threadId, &attr, ThreadDump, &dumpers[i]) == 0);
   }
@@ -689,47 +695,12 @@
   }
 }
 
-TEST(libbacktrace, thread_multiple_dump_same_thread) {
-  pthread_attr_t attr;
-  pthread_attr_init(&attr);
-  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
-  thread_t runner;
-  runner.tid = 0;
-  runner.state = 0;
-  ASSERT_TRUE(pthread_create(&runner.threadId, &attr, ThreadMaxRun, &runner) == 0);
+TEST(libbacktrace, thread_multiple_dump) {
+  MultipleThreadDumpTest(false);
+}
 
-  // Wait for tids to be set.
-  ASSERT_TRUE(WaitForNonZero(&runner.state, 30));
-
-  // Start all of the dumpers at once, they will spin until they are signalled
-  // to begin their dump run.
-  int32_t dump_now = 0;
-  // Dump the same thread NUM_THREADS simultaneously.
-  std::vector<dump_thread_t> dumpers(NUM_THREADS);
-  for (size_t i = 0; i < NUM_THREADS; i++) {
-    dumpers[i].thread.tid = runner.tid;
-    dumpers[i].thread.state = 0;
-    dumpers[i].done = 0;
-    dumpers[i].now = &dump_now;
-
-    ASSERT_TRUE(pthread_create(&dumpers[i].thread.threadId, &attr, ThreadDump, &dumpers[i]) == 0);
-  }
-
-  // Start all of the dumpers going at once.
-  android_atomic_acquire_store(1, &dump_now);
-
-  for (size_t i = 0; i < NUM_THREADS; i++) {
-    ASSERT_TRUE(WaitForNonZero(&dumpers[i].done, 30));
-
-    ASSERT_TRUE(dumpers[i].backtrace != nullptr);
-    VerifyMaxDump(dumpers[i].backtrace);
-
-    delete dumpers[i].backtrace;
-    dumpers[i].backtrace = nullptr;
-  }
-
-  // Tell the runner thread to exit its infinite loop.
-  android_atomic_acquire_store(0, &runner.state);
+TEST(libbacktrace, thread_multiple_dump_same_map) {
+  MultipleThreadDumpTest(true);
 }
 
 // This test is for UnwindMaps that should share the same map cursor when
diff --git a/libsysutils/src/NetlinkEvent.cpp b/libsysutils/src/NetlinkEvent.cpp
index 00b1ee2..7f92904 100644
--- a/libsysutils/src/NetlinkEvent.cpp
+++ b/libsysutils/src/NetlinkEvent.cpp
@@ -501,6 +501,8 @@
         asprintf(&mParams[0], "INTERFACE=%s", ifname);
         asprintf(&mParams[1], "LIFETIME=%u", lifetime);
         mParams[2] = buf;
+    } else if (opthdr->nd_opt_type == ND_OPT_DNSSL) {
+        // TODO: support DNSSL.
     } else {
         SLOGD("Unknown ND option type %d\n", opthdr->nd_opt_type);
         return false;
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index 40364fe..75aa427 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -130,6 +130,7 @@
         "tests/RegsStepIfSignalHandlerTest.cpp",
         "tests/RegsTest.cpp",
         "tests/SymbolsTest.cpp",
+        "tests/UnwindOfflineTest.cpp",
         "tests/UnwindTest.cpp",
         "tests/UnwinderTest.cpp",
     ],
@@ -153,6 +154,8 @@
     data: [
         "tests/files/elf32.xz",
         "tests/files/elf64.xz",
+        "tests/files/offline/straddle_arm32/*",
+        "tests/files/offline/straddle_arm64/*",
     ],
 }
 
diff --git a/libunwindstack/DwarfEhFrame.h b/libunwindstack/DwarfEhFrame.h
index 561d23a..2589c89 100644
--- a/libunwindstack/DwarfEhFrame.h
+++ b/libunwindstack/DwarfEhFrame.h
@@ -40,7 +40,7 @@
 
   uint64_t AdjustPcFromFde(uint64_t pc) override {
     // The eh_frame uses relative pcs.
-    return pc + this->memory_.cur_offset();
+    return pc + this->memory_.cur_offset() - 4;
   }
 };
 
diff --git a/libunwindstack/Elf.cpp b/libunwindstack/Elf.cpp
index edf7ac2..48e33ee 100644
--- a/libunwindstack/Elf.cpp
+++ b/libunwindstack/Elf.cpp
@@ -18,6 +18,7 @@
 #include <string.h>
 
 #include <memory>
+#include <mutex>
 #include <string>
 
 #define LOG_TAG "unwind"
@@ -87,6 +88,7 @@
 }
 
 bool Elf::GetSoname(std::string* name) {
+  std::lock_guard<std::mutex> guard(lock_);
   return valid_ && interface_->GetSoname(name);
 }
 
@@ -95,14 +97,15 @@
 }
 
 bool Elf::GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset) {
+  std::lock_guard<std::mutex> guard(lock_);
   return valid_ && (interface_->GetFunctionName(addr, load_bias_, name, func_offset) ||
                     (gnu_debugdata_interface_ && gnu_debugdata_interface_->GetFunctionName(
                                                      addr, load_bias_, name, func_offset)));
 }
 
 // The relative pc is always relative to the start of the map from which it comes.
-bool Elf::Step(uint64_t rel_pc, uint64_t elf_offset, Regs* regs, Memory* process_memory,
-               bool* finished) {
+bool Elf::Step(uint64_t rel_pc, uint64_t adjusted_rel_pc, uint64_t elf_offset, Regs* regs,
+               Memory* process_memory, bool* finished) {
   if (!valid_) {
     return false;
   }
@@ -114,14 +117,16 @@
   }
 
   // Adjust the load bias to get the real relative pc.
-  if (rel_pc < load_bias_) {
+  if (adjusted_rel_pc < load_bias_) {
     return false;
   }
-  rel_pc -= load_bias_;
+  adjusted_rel_pc -= load_bias_;
 
-  return interface_->Step(rel_pc, regs, process_memory, finished) ||
+  // Lock during the step which can update information in the object.
+  std::lock_guard<std::mutex> guard(lock_);
+  return interface_->Step(adjusted_rel_pc, regs, process_memory, finished) ||
          (gnu_debugdata_interface_ &&
-          gnu_debugdata_interface_->Step(rel_pc, regs, process_memory, finished));
+          gnu_debugdata_interface_->Step(adjusted_rel_pc, regs, process_memory, finished));
 }
 
 bool Elf::IsValidElf(Memory* memory) {
diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index 140d05a..5417659 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -19,6 +19,7 @@
 #include <unistd.h>
 
 #include <memory>
+#include <mutex>
 #include <string>
 
 #include <unwindstack/Elf.h>
@@ -105,6 +106,9 @@
 }
 
 Elf* MapInfo::GetElf(const std::shared_ptr<Memory>& process_memory, bool init_gnu_debugdata) {
+  // Make sure no other thread is trying to add the elf to this map.
+  std::lock_guard<std::mutex> guard(mutex_);
+
   if (elf) {
     return elf;
   }
diff --git a/libunwindstack/Maps.cpp b/libunwindstack/Maps.cpp
index 5e1c0a2..56370c1 100644
--- a/libunwindstack/Maps.cpp
+++ b/libunwindstack/Maps.cpp
@@ -44,7 +44,7 @@
   size_t last = maps_.size();
   while (first < last) {
     size_t index = (first + last) / 2;
-    MapInfo* cur = &maps_[index];
+    MapInfo* cur = maps_[index];
     if (pc >= cur->start && pc < cur->end) {
       return cur;
     } else if (pc < cur->start) {
@@ -57,22 +57,22 @@
 }
 
 // Assumes that line does not end in '\n'.
-static bool InternalParseLine(const char* line, MapInfo* map_info) {
+static MapInfo* InternalParseLine(const char* line) {
   // Do not use a sscanf implementation since it is not performant.
 
   // Example linux /proc/<pid>/maps lines:
   // 6f000000-6f01e000 rwxp 00000000 00:0c 16389419   /system/lib/libcomposer.so
   char* str;
   const char* old_str = line;
-  map_info->start = strtoul(old_str, &str, 16);
+  uint64_t start = strtoull(old_str, &str, 16);
   if (old_str == str || *str++ != '-') {
-    return false;
+    return nullptr;
   }
 
   old_str = str;
-  map_info->end = strtoul(old_str, &str, 16);
+  uint64_t end = strtoull(old_str, &str, 16);
   if (old_str == str || !std::isspace(*str++)) {
-    return false;
+    return nullptr;
   }
 
   while (std::isspace(*str)) {
@@ -81,82 +81,81 @@
 
   // Parse permissions data.
   if (*str == '\0') {
-    return false;
+    return nullptr;
   }
-  map_info->flags = 0;
+  uint16_t flags = 0;
   if (*str == 'r') {
-    map_info->flags |= PROT_READ;
+    flags |= PROT_READ;
   } else if (*str != '-') {
-    return false;
+    return nullptr;
   }
   str++;
   if (*str == 'w') {
-    map_info->flags |= PROT_WRITE;
+    flags |= PROT_WRITE;
   } else if (*str != '-') {
-    return false;
+    return nullptr;
   }
   str++;
   if (*str == 'x') {
-    map_info->flags |= PROT_EXEC;
+    flags |= PROT_EXEC;
   } else if (*str != '-') {
-    return false;
+    return nullptr;
   }
   str++;
   if (*str != 'p' && *str != 's') {
-    return false;
+    return nullptr;
   }
   str++;
 
   if (!std::isspace(*str++)) {
-    return false;
+    return nullptr;
   }
 
   old_str = str;
-  map_info->offset = strtoul(old_str, &str, 16);
+  uint64_t offset = strtoull(old_str, &str, 16);
   if (old_str == str || !std::isspace(*str)) {
-    return false;
+    return nullptr;
   }
 
   // Ignore the 00:00 values.
   old_str = str;
-  (void)strtoul(old_str, &str, 16);
+  (void)strtoull(old_str, &str, 16);
   if (old_str == str || *str++ != ':') {
-    return false;
+    return nullptr;
   }
   if (std::isspace(*str)) {
-    return false;
+    return nullptr;
   }
 
   // Skip the inode.
   old_str = str;
-  (void)strtoul(str, &str, 16);
+  (void)strtoull(str, &str, 16);
   if (old_str == str || !std::isspace(*str++)) {
-    return false;
+    return nullptr;
   }
 
   // Skip decimal digit.
   old_str = str;
-  (void)strtoul(old_str, &str, 10);
+  (void)strtoull(old_str, &str, 10);
   if (old_str == str || (!std::isspace(*str) && *str != '\0')) {
-    return false;
+    return nullptr;
   }
 
   while (std::isspace(*str)) {
     str++;
   }
   if (*str == '\0') {
-    map_info->name = str;
-    return true;
+    return new MapInfo(start, end, offset, flags, "");
   }
 
   // Save the name data.
-  map_info->name = str;
+  std::string name(str);
 
   // Mark a device map in /dev/ and not in /dev/ashmem/ specially.
-  if (map_info->name.substr(0, 5) == "/dev/" && map_info->name.substr(5, 7) != "ashmem/") {
-    map_info->flags |= MAPS_FLAGS_DEVICE_MAP;
+  if (name.substr(0, 5) == "/dev/" && name.substr(5, 7) != "ashmem/") {
+    flags |= MAPS_FLAGS_DEVICE_MAP;
   }
-  return true;
+  return new MapInfo(start, end, offset, flags, name);
 }
 
 bool Maps::Parse() {
@@ -187,8 +186,8 @@
       }
       *newline = '\0';
 
-      MapInfo map_info;
-      if (!InternalParseLine(line, &map_info)) {
+      MapInfo* map_info = InternalParseLine(line);
+      if (map_info == nullptr) {
         return_value = false;
         break;
       }
@@ -205,8 +204,7 @@
 
 Maps::~Maps() {
   for (auto& map : maps_) {
-    delete map.elf;
-    map.elf = nullptr;
+    delete map;
   }
 }
 
@@ -222,8 +220,8 @@
       end_of_line++;
     }
 
-    MapInfo map_info;
-    if (!InternalParseLine(line.c_str(), &map_info)) {
+    MapInfo* map_info = InternalParseLine(line.c_str());
+    if (map_info == nullptr) {
       return false;
     }
     maps_.push_back(map_info);
@@ -252,24 +250,27 @@
 
   std::vector<char> name;
   while (true) {
-    MapInfo map_info;
-    ssize_t bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.start, sizeof(map_info.start)));
+    uint64_t start;
+    ssize_t bytes = TEMP_FAILURE_RETRY(read(fd, &start, sizeof(start)));
     if (bytes == 0) {
       break;
     }
-    if (bytes == -1 || bytes != sizeof(map_info.start)) {
+    if (bytes == -1 || bytes != sizeof(start)) {
       return false;
     }
-    bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.end, sizeof(map_info.end)));
-    if (bytes == -1 || bytes != sizeof(map_info.end)) {
+    uint64_t end;
+    bytes = TEMP_FAILURE_RETRY(read(fd, &end, sizeof(end)));
+    if (bytes == -1 || bytes != sizeof(end)) {
       return false;
     }
-    bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.offset, sizeof(map_info.offset)));
-    if (bytes == -1 || bytes != sizeof(map_info.offset)) {
+    uint64_t offset;
+    bytes = TEMP_FAILURE_RETRY(read(fd, &offset, sizeof(offset)));
+    if (bytes == -1 || bytes != sizeof(offset)) {
       return false;
     }
-    bytes = TEMP_FAILURE_RETRY(read(fd, &map_info.flags, sizeof(map_info.flags)));
-    if (bytes == -1 || bytes != sizeof(map_info.flags)) {
+    uint16_t flags;
+    bytes = TEMP_FAILURE_RETRY(read(fd, &flags, sizeof(flags)));
+    if (bytes == -1 || bytes != sizeof(flags)) {
       return false;
     }
     uint16_t len;
@@ -283,9 +284,10 @@
       if (bytes == -1 || bytes != len) {
         return false;
       }
-      map_info.name = std::string(name.data(), len);
+      maps_.push_back(new MapInfo(start, end, offset, flags, std::string(name.data(), len)));
+    } else {
+      maps_.push_back(new MapInfo(start, end, offset, flags, ""));
     }
-    maps_.push_back(map_info);
   }
   return true;
 }
diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 2e46a11..3092a62 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -32,27 +32,20 @@
 
 namespace unwindstack {
 
-void Unwinder::FillInFrame(MapInfo* map_info, Elf* elf, uint64_t rel_pc, bool adjust_pc) {
+void Unwinder::FillInFrame(MapInfo* map_info, Elf* elf, uint64_t adjusted_rel_pc) {
   size_t frame_num = frames_.size();
   frames_.resize(frame_num + 1);
   FrameData* frame = &frames_.at(frame_num);
   frame->num = frame_num;
-  frame->pc = regs_->pc();
   frame->sp = regs_->sp();
-  frame->rel_pc = rel_pc;
+  frame->rel_pc = adjusted_rel_pc;
 
   if (map_info == nullptr) {
+    frame->pc = regs_->pc();
     return;
   }
 
-  if (adjust_pc) {
-    // Don't adjust the first frame pc.
-    frame->rel_pc = regs_->GetAdjustedPc(rel_pc, elf);
-
-    // Adjust the original pc.
-    frame->pc -= rel_pc - frame->rel_pc;
-  }
-
+  frame->pc = map_info->start + adjusted_rel_pc;
   frame->map_name = map_info->name;
   frame->map_offset = map_info->offset;
   frame->map_start = map_info->start;
@@ -92,21 +85,29 @@
 
     MapInfo* map_info = maps_->Find(regs_->pc());
     uint64_t rel_pc;
+    uint64_t adjusted_rel_pc;
     Elf* elf;
     if (map_info == nullptr) {
       rel_pc = regs_->pc();
+      adjusted_rel_pc = rel_pc;
     } else {
       if (ShouldStop(map_suffixes_to_ignore, map_info->name)) {
         break;
       }
       elf = map_info->GetElf(process_memory_, true);
       rel_pc = elf->GetRelPc(regs_->pc(), map_info);
+      if (adjust_pc) {
+        adjusted_rel_pc = regs_->GetAdjustedPc(rel_pc, elf);
+      } else {
+        adjusted_rel_pc = rel_pc;
+      }
     }
 
     if (map_info == nullptr || initial_map_names_to_skip == nullptr ||
         std::find(initial_map_names_to_skip->begin(), initial_map_names_to_skip->end(),
                   basename(map_info->name.c_str())) == initial_map_names_to_skip->end()) {
-      FillInFrame(map_info, elf, rel_pc, adjust_pc);
+      FillInFrame(map_info, elf, adjusted_rel_pc);
+
       // Once a frame is added, stop skipping frames.
       initial_map_names_to_skip = nullptr;
     }
@@ -133,7 +134,8 @@
           in_device_map = true;
         } else {
           bool finished;
-          stepped = elf->Step(rel_pc, map_info->elf_offset, regs_, process_memory_.get(), &finished);
+          stepped = elf->Step(rel_pc, adjusted_rel_pc, map_info->elf_offset, regs_,
+                              process_memory_.get(), &finished);
           if (stepped && finished) {
             break;
           }
diff --git a/libunwindstack/include/unwindstack/Elf.h b/libunwindstack/include/unwindstack/Elf.h
index 294d742..da2ddc0 100644
--- a/libunwindstack/include/unwindstack/Elf.h
+++ b/libunwindstack/include/unwindstack/Elf.h
@@ -20,6 +20,7 @@
 #include <stddef.h>
 
 #include <memory>
+#include <mutex>
 #include <string>
 
 #include <unwindstack/ElfInterface.h>
@@ -50,8 +51,8 @@
 
   uint64_t GetRelPc(uint64_t pc, const MapInfo* map_info);
 
-  bool Step(uint64_t rel_pc, uint64_t elf_offset, Regs* regs, Memory* process_memory,
-            bool* finished);
+  bool Step(uint64_t rel_pc, uint64_t adjusted_rel_pc, uint64_t elf_offset, Regs* regs,
+            Memory* process_memory, bool* finished);
 
   ElfInterface* CreateInterfaceFromMemory(Memory* memory);
 
@@ -80,6 +81,8 @@
   std::unique_ptr<Memory> memory_;
   uint32_t machine_type_;
   uint8_t class_type_;
+  // Protect calls that can modify internal state of the interface object.
+  std::mutex lock_;
 
   std::unique_ptr<Memory> gnu_debugdata_memory_;
   std::unique_ptr<ElfInterface> gnu_debugdata_interface_;
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index f108766..e54b348 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -19,34 +19,48 @@
 
 #include <stdint.h>
 
+#include <mutex>
 #include <string>
 
+#include <unwindstack/Elf.h>
+
 namespace unwindstack {
 
 // Forward declarations.
-class Elf;
 class Memory;
 
 struct MapInfo {
-  uint64_t start;
-  uint64_t end;
-  uint64_t offset;
-  uint16_t flags;
+  MapInfo() = default;
+  MapInfo(uint64_t start, uint64_t end) : start(start), end(end) {}
+  MapInfo(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags, const std::string& name)
+      : start(start), end(end), offset(offset), flags(flags), name(name) {}
+  ~MapInfo() { delete elf; }
+
+  uint64_t start = 0;
+  uint64_t end = 0;
+  uint64_t offset = 0;
+  uint16_t flags = 0;
   std::string name;
   Elf* elf = nullptr;
   // 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.
-  uint64_t elf_offset;
+  uint64_t elf_offset = 0;
 
   // This function guarantees it will never return nullptr.
   Elf* GetElf(const std::shared_ptr<Memory>& process_memory, bool init_gnu_debugdata = false);
 
  private:
+  MapInfo(const MapInfo&) = delete;
+  void operator=(const MapInfo&) = delete;
+
   Memory* GetFileMemory();
 
   Memory* CreateMemory(const std::shared_ptr<Memory>& process_memory);
+
+  // Protect the creation of the elf object.
+  std::mutex mutex_;
 };
 
 }  // namespace unwindstack
diff --git a/libunwindstack/include/unwindstack/Maps.h b/libunwindstack/include/unwindstack/Maps.h
index 22122a9..34fef7f 100644
--- a/libunwindstack/include/unwindstack/Maps.h
+++ b/libunwindstack/include/unwindstack/Maps.h
@@ -42,11 +42,11 @@
 
   virtual const std::string GetMapsFile() const { return ""; }
 
-  typedef std::vector<MapInfo>::iterator iterator;
+  typedef std::vector<MapInfo*>::iterator iterator;
   iterator begin() { return maps_.begin(); }
   iterator end() { return maps_.end(); }
 
-  typedef std::vector<MapInfo>::const_iterator const_iterator;
+  typedef std::vector<MapInfo*>::const_iterator const_iterator;
   const_iterator begin() const { return maps_.begin(); }
   const_iterator end() const { return maps_.end(); }
 
@@ -54,11 +54,11 @@
 
   MapInfo* Get(size_t index) {
     if (index >= maps_.size()) return nullptr;
-    return &maps_[index];
+    return maps_[index];
   }
 
  protected:
-  std::vector<MapInfo> maps_;
+  std::vector<MapInfo*> maps_;
 };
 
 class RemoteMaps : public Maps {
diff --git a/libunwindstack/include/unwindstack/RegsGetLocal.h b/libunwindstack/include/unwindstack/RegsGetLocal.h
index d1461d8..c59e081 100644
--- a/libunwindstack/include/unwindstack/RegsGetLocal.h
+++ b/libunwindstack/include/unwindstack/RegsGetLocal.h
@@ -33,7 +33,7 @@
 
 #if defined(__arm__)
 
-inline void RegsGetLocal(Regs* regs) {
+inline __always_inline void RegsGetLocal(Regs* regs) {
   void* reg_data = regs->RawData();
   asm volatile(
       ".align 2\n"
@@ -57,7 +57,7 @@
 
 #elif defined(__aarch64__)
 
-inline void RegsGetLocal(Regs* regs) {
+inline __always_inline void RegsGetLocal(Regs* regs) {
   void* reg_data = regs->RawData();
   asm volatile(
       "1:\n"
diff --git a/libunwindstack/include/unwindstack/Unwinder.h b/libunwindstack/include/unwindstack/Unwinder.h
index 37a76b2..b64d460 100644
--- a/libunwindstack/include/unwindstack/Unwinder.h
+++ b/libunwindstack/include/unwindstack/Unwinder.h
@@ -70,7 +70,7 @@
   static std::string FormatFrame(const FrameData& frame, bool bits32);
 
  private:
-  void FillInFrame(MapInfo* map_info, Elf* elf, uint64_t rel_pc, bool adjust_pc);
+  void FillInFrame(MapInfo* map_info, Elf* elf, uint64_t adjusted_rel_pc);
 
   size_t max_frames_;
   Maps* maps_;
diff --git a/libunwindstack/tests/DwarfEhFrameTest.cpp b/libunwindstack/tests/DwarfEhFrameTest.cpp
index 53ee719..3a629f8 100644
--- a/libunwindstack/tests/DwarfEhFrameTest.cpp
+++ b/libunwindstack/tests/DwarfEhFrameTest.cpp
@@ -109,23 +109,23 @@
 
   this->eh_frame_->TestGetFdeInfo(0, &info);
   EXPECT_EQ(0x5100U, info.offset);
-  EXPECT_EQ(0x660cU, info.start);
-  EXPECT_EQ(0x680cU, info.end);
+  EXPECT_EQ(0x6608U, info.start);
+  EXPECT_EQ(0x6808U, info.end);
 
   this->eh_frame_->TestGetFdeInfo(1, &info);
   EXPECT_EQ(0x5200U, info.offset);
-  EXPECT_EQ(0x770cU, info.start);
-  EXPECT_EQ(0x7a0cU, info.end);
+  EXPECT_EQ(0x7708U, info.start);
+  EXPECT_EQ(0x7a08U, info.end);
 
   this->eh_frame_->TestGetFdeInfo(2, &info);
   EXPECT_EQ(0x5400U, info.offset);
-  EXPECT_EQ(0x890cU, info.start);
-  EXPECT_EQ(0x8d0cU, info.end);
+  EXPECT_EQ(0x8908U, info.start);
+  EXPECT_EQ(0x8d08U, info.end);
 
   this->eh_frame_->TestGetFdeInfo(3, &info);
   EXPECT_EQ(0x5500U, info.offset);
-  EXPECT_EQ(0x9a0cU, info.start);
-  EXPECT_EQ(0x9f0cU, info.end);
+  EXPECT_EQ(0x9a08U, info.start);
+  EXPECT_EQ(0x9f08U, info.end);
 }
 
 TYPED_TEST_P(DwarfEhFrameTest, Init32_fde_not_following_cie) {
@@ -193,23 +193,23 @@
 
   this->eh_frame_->TestGetFdeInfo(0, &info);
   EXPECT_EQ(0x5100U, info.offset);
-  EXPECT_EQ(0x661cU, info.start);
-  EXPECT_EQ(0x681cU, info.end);
+  EXPECT_EQ(0x6618U, info.start);
+  EXPECT_EQ(0x6818U, info.end);
 
   this->eh_frame_->TestGetFdeInfo(1, &info);
   EXPECT_EQ(0x5200U, info.offset);
-  EXPECT_EQ(0x771cU, info.start);
-  EXPECT_EQ(0x7a1cU, info.end);
+  EXPECT_EQ(0x7718U, info.start);
+  EXPECT_EQ(0x7a18U, info.end);
 
   this->eh_frame_->TestGetFdeInfo(2, &info);
   EXPECT_EQ(0x5400U, info.offset);
-  EXPECT_EQ(0x891cU, info.start);
-  EXPECT_EQ(0x8d1cU, info.end);
+  EXPECT_EQ(0x8918U, info.start);
+  EXPECT_EQ(0x8d18U, info.end);
 
   this->eh_frame_->TestGetFdeInfo(3, &info);
   EXPECT_EQ(0x5500U, info.offset);
-  EXPECT_EQ(0x9a1cU, info.start);
-  EXPECT_EQ(0x9f1cU, info.end);
+  EXPECT_EQ(0x9a18U, info.start);
+  EXPECT_EQ(0x9f18U, info.end);
 }
 
 TYPED_TEST_P(DwarfEhFrameTest, Init64_fde_not_following_cie) {
@@ -261,8 +261,8 @@
   typename DwarfEhFrame<TypeParam>::FdeInfo info(0, 0, 0);
   this->eh_frame_->TestGetFdeInfo(0, &info);
   EXPECT_EQ(0x5100U, info.offset);
-  EXPECT_EQ(0x660aU, info.start);
-  EXPECT_EQ(0x680aU, info.end);
+  EXPECT_EQ(0x6606U, info.start);
+  EXPECT_EQ(0x6806U, info.end);
 }
 
 TYPED_TEST_P(DwarfEhFrameTest, Init_version4) {
@@ -304,8 +304,8 @@
   typename DwarfEhFrame<TypeParam>::FdeInfo info(0, 0, 0);
   this->eh_frame_->TestGetFdeInfo(0, &info);
   EXPECT_EQ(0x5100U, info.offset);
-  EXPECT_EQ(0x660aU, info.start);
-  EXPECT_EQ(0x680aU, info.end);
+  EXPECT_EQ(0x6606U, info.start);
+  EXPECT_EQ(0x6806U, info.end);
 }
 
 TYPED_TEST_P(DwarfEhFrameTest, GetFdeOffsetFromPc) {
@@ -384,8 +384,8 @@
   ASSERT_TRUE(fde != nullptr);
   EXPECT_EQ(0x14010U, fde->cfa_instructions_offset);
   EXPECT_EQ(0x14024U, fde->cfa_instructions_end);
-  EXPECT_EQ(0x1d00cU, fde->pc_start);
-  EXPECT_EQ(0x1d10cU, fde->pc_end);
+  EXPECT_EQ(0x1d008U, fde->pc_start);
+  EXPECT_EQ(0x1d108U, fde->pc_end);
   EXPECT_EQ(0xf000U, fde->cie_offset);
   EXPECT_EQ(0U, fde->lsda_address);
 
@@ -428,8 +428,8 @@
   ASSERT_TRUE(fde != nullptr);
   EXPECT_EQ(0x8024U, fde->cfa_instructions_offset);
   EXPECT_EQ(0x820cU, fde->cfa_instructions_end);
-  EXPECT_EQ(0xd01cU, fde->pc_start);
-  EXPECT_EQ(0xd31cU, fde->pc_end);
+  EXPECT_EQ(0xd018U, fde->pc_start);
+  EXPECT_EQ(0xd318U, fde->pc_end);
   EXPECT_EQ(0x6000U, fde->cie_offset);
   EXPECT_EQ(0U, fde->lsda_address);
 
diff --git a/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp b/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
index 1028ab9..64b325b 100644
--- a/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
+++ b/libunwindstack/tests/DwarfEhFrameWithHdrTest.cpp
@@ -345,8 +345,8 @@
   ASSERT_TRUE(fde != nullptr);
   EXPECT_EQ(0x14010U, fde->cfa_instructions_offset);
   EXPECT_EQ(0x14024U, fde->cfa_instructions_end);
-  EXPECT_EQ(0x1d00cU, fde->pc_start);
-  EXPECT_EQ(0x1d10cU, fde->pc_end);
+  EXPECT_EQ(0x1d008U, fde->pc_start);
+  EXPECT_EQ(0x1d108U, fde->pc_end);
   EXPECT_EQ(0xf000U, fde->cie_offset);
   EXPECT_EQ(0U, fde->lsda_address);
 
@@ -387,8 +387,8 @@
   ASSERT_TRUE(fde != nullptr);
   EXPECT_EQ(0x8024U, fde->cfa_instructions_offset);
   EXPECT_EQ(0x820cU, fde->cfa_instructions_end);
-  EXPECT_EQ(0xd01cU, fde->pc_start);
-  EXPECT_EQ(0xd31cU, fde->pc_end);
+  EXPECT_EQ(0xd018U, fde->pc_start);
+  EXPECT_EQ(0xd318U, fde->pc_end);
   EXPECT_EQ(0x6000U, fde->cie_offset);
   EXPECT_EQ(0U, fde->lsda_address);
 
diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index 4e48fa1..afd113d 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -132,7 +132,7 @@
   ASSERT_FALSE(elf.GetFunctionName(0, &name, &func_offset));
 
   bool finished;
-  ASSERT_FALSE(elf.Step(0, 0, nullptr, nullptr, &finished));
+  ASSERT_FALSE(elf.Step(0, 0, 0, nullptr, nullptr, &finished));
 }
 
 TEST_F(ElfTest, elf32_invalid_machine) {
@@ -273,7 +273,7 @@
 
   elf.FakeSetValid(true);
   elf.FakeSetLoadBias(0);
-  MapInfo map_info{.start = 0x1000, .end = 0x2000};
+  MapInfo map_info(0x1000, 0x2000);
 
   ASSERT_EQ(0x101U, elf.GetRelPc(0x1101, &map_info));
 
@@ -306,7 +306,7 @@
   elf.FakeSetValid(true);
   elf.FakeSetLoadBias(0);
   bool finished;
-  ASSERT_TRUE(elf.Step(0x1000, 0x2000, &regs, &process_memory, &finished));
+  ASSERT_TRUE(elf.Step(0x1000, 0x1000, 0x2000, &regs, &process_memory, &finished));
   EXPECT_FALSE(finished);
   EXPECT_EQ(15U, regs.pc());
   EXPECT_EQ(13U, regs.sp());
@@ -339,7 +339,7 @@
   EXPECT_CALL(*interface, Step(0x1000, &regs, &process_memory, &finished))
       .WillOnce(::testing::Return(true));
 
-  ASSERT_TRUE(elf.Step(0x1000, 0x2000, &regs, &process_memory, &finished));
+  ASSERT_TRUE(elf.Step(0x1004, 0x1000, 0x2000, &regs, &process_memory, &finished));
 }
 
 TEST_F(ElfTest, step_in_interface_non_zero_load_bias) {
@@ -355,12 +355,12 @@
 
   // Invalid relative pc given load_bias.
   bool finished;
-  ASSERT_FALSE(elf.Step(0x1000, 0x2000, &regs, &process_memory, &finished));
+  ASSERT_FALSE(elf.Step(0x1004, 0x1000, 0x2000, &regs, &process_memory, &finished));
 
   EXPECT_CALL(*interface, Step(0x3300, &regs, &process_memory, &finished))
       .WillOnce(::testing::Return(true));
 
-  ASSERT_TRUE(elf.Step(0x7300, 0x2000, &regs, &process_memory, &finished));
+  ASSERT_TRUE(elf.Step(0x7304, 0x7300, 0x2000, &regs, &process_memory, &finished));
 }
 
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/ElfTestUtils.cpp b/libunwindstack/tests/ElfTestUtils.cpp
index 069386b..69163ac 100644
--- a/libunwindstack/tests/ElfTestUtils.cpp
+++ b/libunwindstack/tests/ElfTestUtils.cpp
@@ -47,7 +47,7 @@
   ehdr->e_ehsize = sizeof(Ehdr);
 }
 
-static std::string GetTestFileDirectory() {
+std::string TestGetFileDirectory() {
   std::string exec(testing::internal::GetArgvs()[0]);
   auto const value = exec.find_last_of('/');
   if (value == std::string::npos) {
@@ -102,7 +102,7 @@
   offset = symtab_offset + 0x100;
   if (init_gnu_debugdata) {
     // Read in the compressed elf data and copy it in.
-    name = GetTestFileDirectory();
+    name = TestGetFileDirectory();
     if (elf_class == ELFCLASS32) {
       name += "elf32.xz";
     } else {
diff --git a/libunwindstack/tests/ElfTestUtils.h b/libunwindstack/tests/ElfTestUtils.h
index 6ef00e1..62cd59a 100644
--- a/libunwindstack/tests/ElfTestUtils.h
+++ b/libunwindstack/tests/ElfTestUtils.h
@@ -18,6 +18,7 @@
 #define _LIBUNWINDSTACK_TESTS_ELF_TEST_UTILS_H
 
 #include <functional>
+#include <string>
 
 namespace unwindstack {
 
@@ -30,6 +31,8 @@
 void TestInitGnuDebugdata(uint32_t elf_class, uint32_t machine_type, bool init_gnu_debudata,
                           TestCopyFuncType copy_func);
 
+std::string TestGetFileDirectory();
+
 }  // namespace unwindstack
 
 #endif  // _LIBUNWINDSTACK_TESTS_ELF_TEST_UTILS_H
diff --git a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
index d2aad49..bdcb652 100644
--- a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
+++ b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
@@ -94,7 +94,7 @@
 TemporaryFile MapInfoCreateMemoryTest::elf64_at_map_;
 
 TEST_F(MapInfoCreateMemoryTest, end_le_start) {
-  MapInfo info{.start = 0x100, .end = 0x100, .offset = 0, .name = elf_.path};
+  MapInfo info(0x100, 0x100, 0, 0, elf_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() == nullptr);
@@ -112,7 +112,7 @@
 // Verify that if the offset is non-zero but there is no elf at the offset,
 // that the full file is used.
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_full_file) {
-  MapInfo info{.start = 0x100, .end = 0x200, .offset = 0x100, .name = elf_.path};
+  MapInfo info(0x100, 0x200, 0x100, 0, elf_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
@@ -133,7 +133,7 @@
 // Verify that if the offset is non-zero and there is an elf at that
 // offset, that only part of the file is used.
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file) {
-  MapInfo info{.start = 0x100, .end = 0x200, .offset = 0x100, .name = elf_at_100_.path};
+  MapInfo info(0x100, 0x200, 0x100, 0, elf_at_100_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
@@ -156,7 +156,7 @@
 // embedded elf is bigger than the initial map, the new object is larger
 // than the original map size. Do this for a 32 bit elf and a 64 bit elf.
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file_whole_elf32) {
-  MapInfo info{.start = 0x5000, .end = 0x6000, .offset = 0x1000, .name = elf32_at_map_.path};
+  MapInfo info(0x5000, 0x6000, 0x1000, 0, elf32_at_map_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
@@ -172,7 +172,7 @@
 }
 
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file_whole_elf64) {
-  MapInfo info{.start = 0x7000, .end = 0x8000, .offset = 0x2000, .name = elf64_at_map_.path};
+  MapInfo info(0x7000, 0x8000, 0x2000, 0, elf64_at_map_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
diff --git a/libunwindstack/tests/MapInfoGetElfTest.cpp b/libunwindstack/tests/MapInfoGetElfTest.cpp
index 0b70d13..9973794 100644
--- a/libunwindstack/tests/MapInfoGetElfTest.cpp
+++ b/libunwindstack/tests/MapInfoGetElfTest.cpp
@@ -23,7 +23,9 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <atomic>
 #include <memory>
+#include <thread>
 #include <vector>
 
 #include <android-base/file.h>
@@ -67,52 +69,52 @@
 };
 
 TEST_F(MapInfoGetElfTest, invalid) {
-  MapInfo info{.start = 0x1000, .end = 0x2000, .offset = 0, .flags = PROT_READ, .name = ""};
+  MapInfo info(0x1000, 0x2000, 0, PROT_READ, "");
 
   // The map is empty, but this should still create an invalid elf object.
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
-  ASSERT_TRUE(elf.get() != nullptr);
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_FALSE(elf->valid());
 }
 
 TEST_F(MapInfoGetElfTest, valid32) {
-  MapInfo info{.start = 0x3000, .end = 0x4000, .offset = 0, .flags = PROT_READ, .name = ""};
+  MapInfo info(0x3000, 0x4000, 0, PROT_READ, "");
 
   Elf32_Ehdr ehdr;
   TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
   memory_->SetMemory(0x3000, &ehdr, sizeof(ehdr));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
-  ASSERT_TRUE(elf.get() != nullptr);
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
   EXPECT_EQ(ELFCLASS32, elf->class_type());
 }
 
 TEST_F(MapInfoGetElfTest, valid64) {
-  MapInfo info{.start = 0x8000, .end = 0x9000, .offset = 0, .flags = PROT_READ, .name = ""};
+  MapInfo info(0x8000, 0x9000, 0, PROT_READ, "");
 
   Elf64_Ehdr ehdr;
   TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
   memory_->SetMemory(0x8000, &ehdr, sizeof(ehdr));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
-  ASSERT_TRUE(elf.get() != nullptr);
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
   EXPECT_EQ(ELFCLASS64, elf->class_type());
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_do_not_init32) {
-  MapInfo info{.start = 0x4000, .end = 0x8000, .offset = 0, .flags = PROT_READ, .name = ""};
+  MapInfo info(0x4000, 0x8000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf32_Ehdr, Elf32_Shdr>(ELFCLASS32, EM_ARM, false,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
                                                  memory_->SetMemory(0x4000 + offset, ptr, size);
                                                });
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
-  ASSERT_TRUE(elf.get() != nullptr);
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
   EXPECT_EQ(ELFCLASS32, elf->class_type());
@@ -120,15 +122,15 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_do_not_init64) {
-  MapInfo info{.start = 0x6000, .end = 0x8000, .offset = 0, .flags = PROT_READ, .name = ""};
+  MapInfo info(0x6000, 0x8000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf64_Ehdr, Elf64_Shdr>(ELFCLASS64, EM_AARCH64, false,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
                                                  memory_->SetMemory(0x6000 + offset, ptr, size);
                                                });
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
-  ASSERT_TRUE(elf.get() != nullptr);
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
   EXPECT_EQ(ELFCLASS64, elf->class_type());
@@ -136,15 +138,15 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_init32) {
-  MapInfo info{.start = 0x2000, .end = 0x3000, .offset = 0, .flags = PROT_READ, .name = ""};
+  MapInfo info(0x2000, 0x3000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf32_Ehdr, Elf32_Shdr>(ELFCLASS32, EM_ARM, true,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
                                                  memory_->SetMemory(0x2000 + offset, ptr, size);
                                                });
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, true));
-  ASSERT_TRUE(elf.get() != nullptr);
+  Elf* elf = info.GetElf(process_memory_, true);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
   EXPECT_EQ(ELFCLASS32, elf->class_type());
@@ -152,15 +154,15 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_init64) {
-  MapInfo info{.start = 0x5000, .end = 0x8000, .offset = 0, .flags = PROT_READ, .name = ""};
+  MapInfo info(0x5000, 0x8000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf64_Ehdr, Elf64_Shdr>(ELFCLASS64, EM_AARCH64, true,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
                                                  memory_->SetMemory(0x5000 + offset, ptr, size);
                                                });
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, true));
-  ASSERT_TRUE(elf.get() != nullptr);
+  Elf* elf = info.GetElf(process_memory_, true);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
   EXPECT_EQ(ELFCLASS64, elf->class_type());
@@ -168,32 +170,36 @@
 }
 
 TEST_F(MapInfoGetElfTest, end_le_start) {
-  MapInfo info{.start = 0x1000, .end = 0x1000, .offset = 0, .flags = PROT_READ, .name = elf_.path};
+  MapInfo info(0x1000, 0x1000, 0, PROT_READ, elf_.path);
 
   Elf32_Ehdr ehdr;
   TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
   ASSERT_TRUE(android::base::WriteFully(elf_.fd, &ehdr, sizeof(ehdr)));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_FALSE(elf->valid());
 
+  delete info.elf;
   info.elf = nullptr;
   info.end = 0xfff;
-  elf.reset(info.GetElf(process_memory_, false));
+  elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_FALSE(elf->valid());
 
   // Make sure this test is valid.
+  delete info.elf;
   info.elf = nullptr;
   info.end = 0x2000;
-  elf.reset(info.GetElf(process_memory_, false));
+  elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
 }
 
 // Verify that if the offset is non-zero but there is no elf at the offset,
 // that the full file is used.
 TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_full_file) {
-  MapInfo info{
-      .start = 0x1000, .end = 0x2000, .offset = 0x100, .flags = PROT_READ, .name = elf_.path};
+  MapInfo info(0x1000, 0x2000, 0x100, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x1000);
   memset(buffer.data(), 0, buffer.size());
@@ -202,7 +208,8 @@
   memcpy(buffer.data(), &ehdr, sizeof(ehdr));
   ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   ASSERT_TRUE(elf->memory() != nullptr);
   ASSERT_EQ(0x100U, info.elf_offset);
@@ -221,8 +228,7 @@
 // Verify that if the offset is non-zero and there is an elf at that
 // offset, that only part of the file is used.
 TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_partial_file) {
-  MapInfo info{
-      .start = 0x1000, .end = 0x2000, .offset = 0x2000, .flags = PROT_READ, .name = elf_.path};
+  MapInfo info(0x1000, 0x2000, 0x2000, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x4000);
   memset(buffer.data(), 0, buffer.size());
@@ -231,7 +237,8 @@
   memcpy(&buffer[info.offset], &ehdr, sizeof(ehdr));
   ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   ASSERT_TRUE(elf->memory() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
@@ -251,8 +258,7 @@
 // embedded elf is bigger than the initial map, the new object is larger
 // than the original map size. Do this for a 32 bit elf and a 64 bit elf.
 TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_partial_file_whole_elf32) {
-  MapInfo info{
-      .start = 0x5000, .end = 0x6000, .offset = 0x1000, .flags = PROT_READ, .name = elf_.path};
+  MapInfo info(0x5000, 0x6000, 0x1000, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x4000);
   memset(buffer.data(), 0, buffer.size());
@@ -264,7 +270,8 @@
   memcpy(&buffer[info.offset], &ehdr, sizeof(ehdr));
   ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   ASSERT_TRUE(elf->memory() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
@@ -279,8 +286,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_partial_file_whole_elf64) {
-  MapInfo info{
-      .start = 0x7000, .end = 0x8000, .offset = 0x1000, .flags = PROT_READ, .name = elf_.path};
+  MapInfo info(0x7000, 0x8000, 0x1000, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x4000);
   memset(buffer.data(), 0, buffer.size());
@@ -292,7 +298,8 @@
   memcpy(&buffer[info.offset], &ehdr, sizeof(ehdr));
   ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_TRUE(elf->valid());
   ASSERT_TRUE(elf->memory() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
@@ -307,7 +314,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, process_memory_not_read_only) {
-  MapInfo info{.start = 0x9000, .end = 0xa000, .offset = 0x1000, .flags = 0, .name = ""};
+  MapInfo info(0x9000, 0xa000, 0x1000, 0, "");
 
   // Create valid elf data in process memory only.
   Elf64_Ehdr ehdr;
@@ -317,21 +324,19 @@
   ehdr.e_shnum = 4;
   memory_->SetMemory(0x9000, &ehdr, sizeof(ehdr));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_FALSE(elf->valid());
 
+  delete info.elf;
   info.elf = nullptr;
   info.flags = PROT_READ;
-  elf.reset(info.GetElf(process_memory_, false));
+  elf = info.GetElf(process_memory_, false);
   ASSERT_TRUE(elf->valid());
 }
 
 TEST_F(MapInfoGetElfTest, check_device_maps) {
-  MapInfo info{.start = 0x7000,
-               .end = 0x8000,
-               .offset = 0x1000,
-               .flags = PROT_READ | MAPS_FLAGS_DEVICE_MAP,
-               .name = "/dev/something"};
+  MapInfo info(0x7000, 0x8000, 0x1000, PROT_READ | MAPS_FLAGS_DEVICE_MAP, "/dev/something");
 
   // Create valid elf data in process memory for this to verify that only
   // the name is causing invalid elf data.
@@ -342,20 +347,68 @@
   ehdr.e_shnum = 4;
   memory_->SetMemory(0x7000, &ehdr, sizeof(ehdr));
 
-  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  Elf* elf = info.GetElf(process_memory_, false);
+  ASSERT_TRUE(elf != nullptr);
   ASSERT_FALSE(elf->valid());
 
   // Set the name to nothing to verify that it still fails.
+  delete info.elf;
   info.elf = nullptr;
   info.name = "";
-  elf.reset(info.GetElf(process_memory_, false));
+  elf = info.GetElf(process_memory_, false);
   ASSERT_FALSE(elf->valid());
 
   // Change the flags and verify the elf is valid now.
+  delete info.elf;
   info.elf = nullptr;
   info.flags = PROT_READ;
-  elf.reset(info.GetElf(process_memory_, false));
+  elf = info.GetElf(process_memory_, false);
   ASSERT_TRUE(elf->valid());
 }
 
+TEST_F(MapInfoGetElfTest, multiple_thread_get_elf) {
+  static constexpr size_t kNumConcurrentThreads = 100;
+
+  Elf64_Ehdr ehdr;
+  TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_X86_64);
+  ehdr.e_shoff = 0x2000;
+  ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
+  ehdr.e_shnum = 4;
+  memory_->SetMemory(0x7000, &ehdr, sizeof(ehdr));
+
+  Elf* elf_in_threads[kNumConcurrentThreads];
+  std::vector<std::thread*> threads;
+
+  std::atomic_bool wait;
+  wait = true;
+  // Create all of the threads and have them do the GetElf at the same time
+  // to make it likely that a race will occur.
+  MapInfo info(0x7000, 0x8000, 0x1000, PROT_READ, "");
+  for (size_t i = 0; i < kNumConcurrentThreads; i++) {
+    std::thread* thread = new std::thread([i, this, &wait, &info, &elf_in_threads]() {
+      while (wait)
+        ;
+      Elf* elf = info.GetElf(process_memory_, false);
+      elf_in_threads[i] = elf;
+    });
+    threads.push_back(thread);
+  }
+  ASSERT_TRUE(info.elf == nullptr);
+
+  // Set them all going and wait for the threads to finish.
+  wait = false;
+  for (auto thread : threads) {
+    thread->join();
+    delete thread;
+  }
+
+  // Now verify that all of the elf files are exactly the same and valid.
+  Elf* elf = info.elf;
+  ASSERT_TRUE(elf != nullptr);
+  EXPECT_TRUE(elf->valid());
+  for (size_t i = 0; i < kNumConcurrentThreads; i++) {
+    EXPECT_EQ(elf, elf_in_threads[i]) << "Thread " << i << " mismatched.";
+  }
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MapsTest.cpp b/libunwindstack/tests/MapsTest.cpp
index 2d15a4e..8dc884f 100644
--- a/libunwindstack/tests/MapsTest.cpp
+++ b/libunwindstack/tests/MapsTest.cpp
@@ -35,7 +35,12 @@
     ASSERT_TRUE(maps.Parse()) << "Failed on: " + line;
     MapInfo* element = maps.Get(0);
     ASSERT_TRUE(element != nullptr) << "Failed on: " + line;
-    *info = *element;
+    info->start = element->start;
+    info->end = element->end;
+    info->offset = element->offset;
+    info->flags = element->flags;
+    info->name = element->name;
+    info->elf_offset = element->elf_offset;
   }
 }
 
@@ -139,38 +144,48 @@
 
   ASSERT_TRUE(maps.Parse());
   ASSERT_EQ(5U, maps.Total());
-  auto it = maps.begin();
-  ASSERT_EQ(PROT_NONE, it->flags);
-  ASSERT_EQ(0x1000U, it->start);
-  ASSERT_EQ(0x2000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ("", it->name);
-  ++it;
-  ASSERT_EQ(PROT_READ, it->flags);
-  ASSERT_EQ(0x2000U, it->start);
-  ASSERT_EQ(0x3000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ("", it->name);
-  ++it;
-  ASSERT_EQ(PROT_WRITE, it->flags);
-  ASSERT_EQ(0x3000U, it->start);
-  ASSERT_EQ(0x4000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ("", it->name);
-  ++it;
-  ASSERT_EQ(PROT_EXEC, it->flags);
-  ASSERT_EQ(0x4000U, it->start);
-  ASSERT_EQ(0x5000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ("", it->name);
-  ++it;
-  ASSERT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, it->flags);
-  ASSERT_EQ(0x5000U, it->start);
-  ASSERT_EQ(0x6000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ("", it->name);
-  ++it;
-  ASSERT_EQ(it, maps.end());
+
+  MapInfo* info = maps.Get(0);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(PROT_NONE, info->flags);
+  EXPECT_EQ(0x1000U, info->start);
+  EXPECT_EQ(0x2000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ("", info->name);
+
+  info = maps.Get(1);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(PROT_READ, info->flags);
+  EXPECT_EQ(0x2000U, info->start);
+  EXPECT_EQ(0x3000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ("", info->name);
+
+  info = maps.Get(2);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(PROT_WRITE, info->flags);
+  EXPECT_EQ(0x3000U, info->start);
+  EXPECT_EQ(0x4000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ("", info->name);
+
+  info = maps.Get(3);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(PROT_EXEC, info->flags);
+  EXPECT_EQ(0x4000U, info->start);
+  EXPECT_EQ(0x5000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ("", info->name);
+
+  info = maps.Get(4);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, info->flags);
+  EXPECT_EQ(0x5000U, info->start);
+  EXPECT_EQ(0x6000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ("", info->name);
+
+  ASSERT_TRUE(maps.Get(5) == nullptr);
 }
 
 TEST(MapsTest, parse_name) {
@@ -181,26 +196,32 @@
 
   ASSERT_TRUE(maps.Parse());
   ASSERT_EQ(3U, maps.Total());
-  auto it = maps.begin();
-  ASSERT_EQ("", it->name);
-  ASSERT_EQ(0x7b29b000U, it->start);
-  ASSERT_EQ(0x7b29e000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
-  ++it;
-  ASSERT_EQ("/system/lib/fake.so", it->name);
-  ASSERT_EQ(0x7b29e000U, it->start);
-  ASSERT_EQ(0x7b29f000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
-  ++it;
-  ASSERT_EQ("", it->name);
-  ASSERT_EQ(0x7b29f000U, it->start);
-  ASSERT_EQ(0x7b2a0000U, it->end);
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
-  ++it;
-  ASSERT_EQ(it, maps.end());
+
+  MapInfo* info = maps.Get(0);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ("", info->name);
+  EXPECT_EQ(0x7b29b000U, info->start);
+  EXPECT_EQ(0x7b29e000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, info->flags);
+
+  info = maps.Get(1);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ("/system/lib/fake.so", info->name);
+  EXPECT_EQ(0x7b29e000U, info->start);
+  EXPECT_EQ(0x7b29f000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, info->flags);
+
+  info = maps.Get(2);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ("", info->name);
+  EXPECT_EQ(0x7b29f000U, info->start);
+  EXPECT_EQ(0x7b2a0000U, info->end);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, info->flags);
+
+  ASSERT_TRUE(maps.Get(3) == nullptr);
 }
 
 TEST(MapsTest, parse_offset) {
@@ -210,20 +231,60 @@
 
   ASSERT_TRUE(maps.Parse());
   ASSERT_EQ(2U, maps.Total());
-  auto it = maps.begin();
-  ASSERT_EQ(0U, it->offset);
-  ASSERT_EQ(0xa000U, it->start);
-  ASSERT_EQ(0xe000U, it->end);
-  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
-  ASSERT_EQ("/system/lib/fake.so", it->name);
+
+  MapInfo* info = maps.Get(0);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0U, info->offset);
+  EXPECT_EQ(0xa000U, info->start);
+  EXPECT_EQ(0xe000U, info->end);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, info->flags);
+  EXPECT_EQ("/system/lib/fake.so", info->name);
+
+  info = maps.Get(1);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0xa12345U, info->offset);
+  EXPECT_EQ(0xe000U, info->start);
+  EXPECT_EQ(0xf000U, info->end);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, info->flags);
+  EXPECT_EQ("/system/lib/fake.so", info->name);
+
+  ASSERT_TRUE(maps.Get(2) == nullptr);
+}
+
+TEST(MapsTest, iterate) {
+  BufferMaps maps(
+      "a000-e000 rw-p 00000000 00:00 0 /system/lib/fake.so\n"
+      "e000-f000 rw-p 00a12345 00:00 0 /system/lib/fake.so\n");
+
+  ASSERT_TRUE(maps.Parse());
+  ASSERT_EQ(2U, maps.Total());
+
+  Maps::iterator it = maps.begin();
+  EXPECT_EQ(0xa000U, (*it)->start);
+  EXPECT_EQ(0xe000U, (*it)->end);
   ++it;
-  ASSERT_EQ(0xa12345U, it->offset);
-  ASSERT_EQ(0xe000U, it->start);
-  ASSERT_EQ(0xf000U, it->end);
-  ASSERT_EQ(PROT_READ | PROT_WRITE, it->flags);
-  ASSERT_EQ("/system/lib/fake.so", it->name);
+  EXPECT_EQ(0xe000U, (*it)->start);
+  EXPECT_EQ(0xf000U, (*it)->end);
   ++it;
-  ASSERT_EQ(maps.end(), it);
+  EXPECT_EQ(maps.end(), it);
+}
+
+TEST(MapsTest, const_iterate) {
+  BufferMaps maps(
+      "a000-e000 rw-p 00000000 00:00 0 /system/lib/fake.so\n"
+      "e000-f000 rw-p 00a12345 00:00 0 /system/lib/fake.so\n");
+
+  ASSERT_TRUE(maps.Parse());
+  ASSERT_EQ(2U, maps.Total());
+
+  Maps::const_iterator it = maps.begin();
+  EXPECT_EQ(0xa000U, (*it)->start);
+  EXPECT_EQ(0xe000U, (*it)->end);
+  ++it;
+  EXPECT_EQ(0xe000U, (*it)->start);
+  EXPECT_EQ(0xf000U, (*it)->end);
+  ++it;
+  EXPECT_EQ(maps.end(), it);
 }
 
 TEST(MapsTest, device) {
@@ -235,18 +296,23 @@
 
   ASSERT_TRUE(maps.Parse());
   ASSERT_EQ(4U, maps.Total());
-  auto it = maps.begin();
-  ASSERT_TRUE(it->flags & 0x8000);
-  ASSERT_EQ("/dev/", it->name);
-  ++it;
-  ASSERT_TRUE(it->flags & 0x8000);
-  ASSERT_EQ("/dev/does_not_exist", it->name);
-  ++it;
-  ASSERT_FALSE(it->flags & 0x8000);
-  ASSERT_EQ("/dev/ashmem/does_not_exist", it->name);
-  ++it;
-  ASSERT_FALSE(it->flags & 0x8000);
-  ASSERT_EQ("/devsomething/does_not_exist", it->name);
+
+  MapInfo* info = maps.Get(0);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_TRUE(info->flags & 0x8000);
+  EXPECT_EQ("/dev/", info->name);
+
+  info = maps.Get(1);
+  EXPECT_TRUE(info->flags & 0x8000);
+  EXPECT_EQ("/dev/does_not_exist", info->name);
+
+  info = maps.Get(2);
+  EXPECT_FALSE(info->flags & 0x8000);
+  EXPECT_EQ("/dev/ashmem/does_not_exist", info->name);
+
+  info = maps.Get(3);
+  EXPECT_FALSE(info->flags & 0x8000);
+  EXPECT_EQ("/devsomething/does_not_exist", info->name);
 }
 
 TEST(MapsTest, file_smoke) {
@@ -263,26 +329,32 @@
 
   ASSERT_TRUE(maps.Parse());
   ASSERT_EQ(3U, maps.Total());
-  auto it = maps.begin();
-  ASSERT_EQ(0x7b29b000U, it->start);
-  ASSERT_EQ(0x7b29e000U, it->end);
-  ASSERT_EQ(0xa0000000U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
-  ASSERT_EQ("/fake.so", it->name);
-  ++it;
-  ASSERT_EQ(0x7b2b0000U, it->start);
-  ASSERT_EQ(0x7b2e0000U, it->end);
-  ASSERT_EQ(0xb0000000U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
-  ASSERT_EQ("/fake2.so", it->name);
-  ++it;
-  ASSERT_EQ(0x7b2e0000U, it->start);
-  ASSERT_EQ(0x7b2f0000U, it->end);
-  ASSERT_EQ(0xc0000000U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
-  ASSERT_EQ("/fake3.so", it->name);
-  ++it;
-  ASSERT_EQ(it, maps.end());
+
+  MapInfo* info = maps.Get(0);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0x7b29b000U, info->start);
+  EXPECT_EQ(0x7b29e000U, info->end);
+  EXPECT_EQ(0xa0000000U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_EXEC, info->flags);
+  EXPECT_EQ("/fake.so", info->name);
+
+  info = maps.Get(1);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0x7b2b0000U, info->start);
+  EXPECT_EQ(0x7b2e0000U, info->end);
+  EXPECT_EQ(0xb0000000U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_EXEC, info->flags);
+  EXPECT_EQ("/fake2.so", info->name);
+
+  info = maps.Get(2);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0x7b2e0000U, info->start);
+  EXPECT_EQ(0x7b2f0000U, info->end);
+  EXPECT_EQ(0xc0000000U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_EXEC, info->flags);
+  EXPECT_EQ("/fake3.so", info->name);
+
+  ASSERT_TRUE(maps.Get(3) == nullptr);
 }
 
 TEST(MapsTest, file_no_map_name) {
@@ -299,26 +371,32 @@
 
   ASSERT_TRUE(maps.Parse());
   ASSERT_EQ(3U, maps.Total());
-  auto it = maps.begin();
-  ASSERT_EQ(0x7b29b000U, it->start);
-  ASSERT_EQ(0x7b29e000U, it->end);
-  ASSERT_EQ(0xa0000000U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
-  ASSERT_EQ("", it->name);
-  ++it;
-  ASSERT_EQ(0x7b2b0000U, it->start);
-  ASSERT_EQ(0x7b2e0000U, it->end);
-  ASSERT_EQ(0xb0000000U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
-  ASSERT_EQ("/fake2.so", it->name);
-  ++it;
-  ASSERT_EQ(0x7b2e0000U, it->start);
-  ASSERT_EQ(0x7b2f0000U, it->end);
-  ASSERT_EQ(0xc0000000U, it->offset);
-  ASSERT_EQ(PROT_READ | PROT_EXEC, it->flags);
-  ASSERT_EQ("", it->name);
-  ++it;
-  ASSERT_EQ(it, maps.end());
+
+  MapInfo* info = maps.Get(0);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0x7b29b000U, info->start);
+  EXPECT_EQ(0x7b29e000U, info->end);
+  EXPECT_EQ(0xa0000000U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_EXEC, info->flags);
+  EXPECT_EQ("", info->name);
+
+  info = maps.Get(1);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0x7b2b0000U, info->start);
+  EXPECT_EQ(0x7b2e0000U, info->end);
+  EXPECT_EQ(0xb0000000U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_EXEC, info->flags);
+  EXPECT_EQ("/fake2.so", info->name);
+
+  info = maps.Get(2);
+  ASSERT_TRUE(info != nullptr);
+  EXPECT_EQ(0x7b2e0000U, info->start);
+  EXPECT_EQ(0x7b2f0000U, info->end);
+  EXPECT_EQ(0xc0000000U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_EXEC, info->flags);
+  EXPECT_EQ("", info->name);
+
+  ASSERT_TRUE(maps.Get(3) == nullptr);
 }
 
 // Verify that a file that crosses a buffer is parsed correctly.
@@ -435,10 +513,10 @@
   ASSERT_EQ(5000U, maps.Total());
   for (size_t i = 0; i < 5000; i++) {
     MapInfo* info = maps.Get(i);
-    ASSERT_EQ(start + i * 4096, info->start) << "Failed at map " + std::to_string(i);
-    ASSERT_EQ(start + (i + 1) * 4096, info->end) << "Failed at map " + std::to_string(i);
+    EXPECT_EQ(start + i * 4096, info->start) << "Failed at map " + std::to_string(i);
+    EXPECT_EQ(start + (i + 1) * 4096, info->end) << "Failed at map " + std::to_string(i);
     std::string name = "/fake" + std::to_string(i) + ".so";
-    ASSERT_EQ(name, info->name) << "Failed at map " + std::to_string(i);
+    EXPECT_EQ(name, info->name) << "Failed at map " + std::to_string(i);
   }
 }
 
@@ -452,52 +530,52 @@
   ASSERT_TRUE(maps.Parse());
   ASSERT_EQ(5U, maps.Total());
 
-  ASSERT_TRUE(maps.Find(0x500) == nullptr);
-  ASSERT_TRUE(maps.Find(0x2000) == nullptr);
-  ASSERT_TRUE(maps.Find(0x5010) == nullptr);
-  ASSERT_TRUE(maps.Find(0x9a00) == nullptr);
-  ASSERT_TRUE(maps.Find(0xf000) == nullptr);
-  ASSERT_TRUE(maps.Find(0xf010) == nullptr);
+  EXPECT_TRUE(maps.Find(0x500) == nullptr);
+  EXPECT_TRUE(maps.Find(0x2000) == nullptr);
+  EXPECT_TRUE(maps.Find(0x5010) == nullptr);
+  EXPECT_TRUE(maps.Find(0x9a00) == nullptr);
+  EXPECT_TRUE(maps.Find(0xf000) == nullptr);
+  EXPECT_TRUE(maps.Find(0xf010) == nullptr);
 
   MapInfo* info = maps.Find(0x1000);
   ASSERT_TRUE(info != nullptr);
-  ASSERT_EQ(0x1000U, info->start);
-  ASSERT_EQ(0x2000U, info->end);
-  ASSERT_EQ(0x10U, info->offset);
-  ASSERT_EQ(PROT_READ, info->flags);
-  ASSERT_EQ("/system/lib/fake1.so", info->name);
+  EXPECT_EQ(0x1000U, info->start);
+  EXPECT_EQ(0x2000U, info->end);
+  EXPECT_EQ(0x10U, info->offset);
+  EXPECT_EQ(PROT_READ, info->flags);
+  EXPECT_EQ("/system/lib/fake1.so", info->name);
 
   info = maps.Find(0x3020);
   ASSERT_TRUE(info != nullptr);
-  ASSERT_EQ(0x3000U, info->start);
-  ASSERT_EQ(0x4000U, info->end);
-  ASSERT_EQ(0x20U, info->offset);
-  ASSERT_EQ(PROT_WRITE, info->flags);
-  ASSERT_EQ("/system/lib/fake2.so", info->name);
+  EXPECT_EQ(0x3000U, info->start);
+  EXPECT_EQ(0x4000U, info->end);
+  EXPECT_EQ(0x20U, info->offset);
+  EXPECT_EQ(PROT_WRITE, info->flags);
+  EXPECT_EQ("/system/lib/fake2.so", info->name);
 
   info = maps.Find(0x6020);
   ASSERT_TRUE(info != nullptr);
-  ASSERT_EQ(0x6000U, info->start);
-  ASSERT_EQ(0x8000U, info->end);
-  ASSERT_EQ(0x30U, info->offset);
-  ASSERT_EQ(PROT_EXEC, info->flags);
-  ASSERT_EQ("/system/lib/fake3.so", info->name);
+  EXPECT_EQ(0x6000U, info->start);
+  EXPECT_EQ(0x8000U, info->end);
+  EXPECT_EQ(0x30U, info->offset);
+  EXPECT_EQ(PROT_EXEC, info->flags);
+  EXPECT_EQ("/system/lib/fake3.so", info->name);
 
   info = maps.Find(0xafff);
   ASSERT_TRUE(info != nullptr);
-  ASSERT_EQ(0xa000U, info->start);
-  ASSERT_EQ(0xb000U, info->end);
-  ASSERT_EQ(0x40U, info->offset);
-  ASSERT_EQ(PROT_READ | PROT_WRITE, info->flags);
-  ASSERT_EQ("/system/lib/fake4.so", info->name);
+  EXPECT_EQ(0xa000U, info->start);
+  EXPECT_EQ(0xb000U, info->end);
+  EXPECT_EQ(0x40U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_WRITE, info->flags);
+  EXPECT_EQ("/system/lib/fake4.so", info->name);
 
   info = maps.Find(0xe500);
   ASSERT_TRUE(info != nullptr);
-  ASSERT_EQ(0xe000U, info->start);
-  ASSERT_EQ(0xf000U, info->end);
-  ASSERT_EQ(0x50U, info->offset);
-  ASSERT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, info->flags);
-  ASSERT_EQ("/system/lib/fake5.so", info->name);
+  EXPECT_EQ(0xe000U, info->start);
+  EXPECT_EQ(0xf000U, info->end);
+  EXPECT_EQ(0x50U, info->offset);
+  EXPECT_EQ(PROT_READ | PROT_WRITE | PROT_EXEC, info->flags);
+  EXPECT_EQ("/system/lib/fake5.so", info->name);
 }
 
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/RegsTest.cpp b/libunwindstack/tests/RegsTest.cpp
index 2a02669..3320f77 100644
--- a/libunwindstack/tests/RegsTest.cpp
+++ b/libunwindstack/tests/RegsTest.cpp
@@ -147,28 +147,29 @@
 }
 
 TEST_F(RegsTest, elf_invalid) {
-  Elf invalid_elf(new MemoryFake);
   RegsArm regs_arm;
   RegsArm64 regs_arm64;
   RegsX86 regs_x86;
   RegsX86_64 regs_x86_64;
-  MapInfo map_info{.start = 0x1000, .end = 0x2000};
+  MapInfo map_info(0x1000, 0x2000);
+  Elf* invalid_elf = new Elf(new MemoryFake);
+  map_info.elf = invalid_elf;
 
   regs_arm.set_pc(0x1500);
-  ASSERT_EQ(0x500U, invalid_elf.GetRelPc(regs_arm.pc(), &map_info));
-  ASSERT_EQ(0x500U, regs_arm.GetAdjustedPc(0x500U, &invalid_elf));
+  EXPECT_EQ(0x500U, invalid_elf->GetRelPc(regs_arm.pc(), &map_info));
+  EXPECT_EQ(0x500U, regs_arm.GetAdjustedPc(0x500U, invalid_elf));
 
   regs_arm64.set_pc(0x1600);
-  ASSERT_EQ(0x600U, invalid_elf.GetRelPc(regs_arm64.pc(), &map_info));
-  ASSERT_EQ(0x600U, regs_arm64.GetAdjustedPc(0x600U, &invalid_elf));
+  EXPECT_EQ(0x600U, invalid_elf->GetRelPc(regs_arm64.pc(), &map_info));
+  EXPECT_EQ(0x600U, regs_arm64.GetAdjustedPc(0x600U, invalid_elf));
 
   regs_x86.set_pc(0x1700);
-  ASSERT_EQ(0x700U, invalid_elf.GetRelPc(regs_x86.pc(), &map_info));
-  ASSERT_EQ(0x700U, regs_x86.GetAdjustedPc(0x700U, &invalid_elf));
+  EXPECT_EQ(0x700U, invalid_elf->GetRelPc(regs_x86.pc(), &map_info));
+  EXPECT_EQ(0x700U, regs_x86.GetAdjustedPc(0x700U, invalid_elf));
 
   regs_x86_64.set_pc(0x1800);
-  ASSERT_EQ(0x800U, invalid_elf.GetRelPc(regs_x86_64.pc(), &map_info));
-  ASSERT_EQ(0x800U, regs_x86_64.GetAdjustedPc(0x800U, &invalid_elf));
+  EXPECT_EQ(0x800U, invalid_elf->GetRelPc(regs_x86_64.pc(), &map_info));
+  EXPECT_EQ(0x800U, regs_x86_64.GetAdjustedPc(0x800U, invalid_elf));
 }
 
 TEST_F(RegsTest, arm_set_from_raw) {
diff --git a/libunwindstack/tests/UnwindOfflineTest.cpp b/libunwindstack/tests/UnwindOfflineTest.cpp
new file mode 100644
index 0000000..d24abe4
--- /dev/null
+++ b/libunwindstack/tests/UnwindOfflineTest.cpp
@@ -0,0 +1,153 @@
+/*
+ * 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.
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <gtest/gtest.h>
+
+#include <string>
+#include <vector>
+
+#include <unwindstack/Maps.h>
+#include <unwindstack/Memory.h>
+#include <unwindstack/Regs.h>
+#include <unwindstack/Unwinder.h>
+
+#include "Machine.h"
+
+#include "ElfTestUtils.h"
+
+namespace unwindstack {
+
+static std::string DumpFrames(Unwinder& unwinder) {
+  std::string str;
+  for (size_t i = 0; i < unwinder.NumFrames(); i++) {
+    str += unwinder.FormatFrame(i) + "\n";
+  }
+  return str;
+}
+
+TEST(UnwindOfflineTest, pc_straddle_arm32) {
+  std::string dir(TestGetFileDirectory() + "offline/straddle_arm32/");
+
+  MemoryOffline* memory = new MemoryOffline;
+  ASSERT_TRUE(memory->Init((dir + "stack.data").c_str(), 0));
+
+  FILE* fp = fopen((dir + "regs.txt").c_str(), "r");
+  ASSERT_TRUE(fp != nullptr);
+  RegsArm regs;
+  uint64_t reg_value;
+  ASSERT_EQ(1, fscanf(fp, "pc: %" SCNx64 "\n", &reg_value));
+  regs[ARM_REG_PC] = reg_value;
+  ASSERT_EQ(1, fscanf(fp, "sp: %" SCNx64 "\n", &reg_value));
+  regs[ARM_REG_SP] = reg_value;
+  ASSERT_EQ(1, fscanf(fp, "lr: %" SCNx64 "\n", &reg_value));
+  regs[ARM_REG_LR] = reg_value;
+  regs.SetFromRaw();
+  fclose(fp);
+
+  fp = fopen((dir + "maps.txt").c_str(), "r");
+  ASSERT_TRUE(fp != nullptr);
+  // The file is guaranteed to be less than 4096 bytes.
+  std::vector<char> buffer(4096);
+  ASSERT_NE(0U, fread(buffer.data(), 1, buffer.size(), fp));
+  fclose(fp);
+
+  BufferMaps maps(buffer.data());
+  ASSERT_TRUE(maps.Parse());
+
+  ASSERT_EQ(static_cast<uint32_t>(EM_ARM), regs.MachineType());
+
+  std::shared_ptr<Memory> process_memory(memory);
+
+  char* cwd = getcwd(nullptr, 0);
+  ASSERT_EQ(0, chdir(dir.c_str()));
+  Unwinder unwinder(128, &maps, &regs, process_memory);
+  unwinder.Unwind();
+  ASSERT_EQ(0, chdir(cwd));
+  free(cwd);
+
+  std::string frame_info(DumpFrames(unwinder));
+  ASSERT_EQ(4U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+  EXPECT_EQ(
+      "  #00 pc 0001a9f8  libc.so (abort+63)\n"
+      "  #01 pc 00006a1b  libbase.so (_ZN7android4base14DefaultAborterEPKc+6)\n"
+      "  #02 pc 00007441  libbase.so (_ZN7android4base10LogMessageD2Ev+748)\n"
+      "  #03 pc 00015149  /does/not/exist/libhidlbase.so\n",
+      frame_info);
+}
+
+TEST(UnwindOfflineTest, pc_straddle_arm64) {
+  std::string dir(TestGetFileDirectory() + "offline/straddle_arm64/");
+
+  MemoryOffline* memory = new MemoryOffline;
+  ASSERT_TRUE(memory->Init((dir + "stack.data").c_str(), 0));
+
+  FILE* fp = fopen((dir + "regs.txt").c_str(), "r");
+  ASSERT_TRUE(fp != nullptr);
+  RegsArm64 regs;
+  uint64_t reg_value;
+  ASSERT_EQ(1, fscanf(fp, "pc: %" SCNx64 "\n", &reg_value));
+  regs[ARM64_REG_PC] = reg_value;
+  ASSERT_EQ(1, fscanf(fp, "sp: %" SCNx64 "\n", &reg_value));
+  regs[ARM64_REG_SP] = reg_value;
+  ASSERT_EQ(1, fscanf(fp, "lr: %" SCNx64 "\n", &reg_value));
+  regs[ARM64_REG_LR] = reg_value;
+  ASSERT_EQ(1, fscanf(fp, "x29: %" SCNx64 "\n", &reg_value));
+  regs[ARM64_REG_R29] = reg_value;
+  regs.SetFromRaw();
+  fclose(fp);
+
+  fp = fopen((dir + "maps.txt").c_str(), "r");
+  ASSERT_TRUE(fp != nullptr);
+  // The file is guaranteed to be less than 4096 bytes.
+  std::vector<char> buffer(4096);
+  ASSERT_NE(0U, fread(buffer.data(), 1, buffer.size(), fp));
+  fclose(fp);
+
+  BufferMaps maps(buffer.data());
+  ASSERT_TRUE(maps.Parse());
+
+  ASSERT_EQ(static_cast<uint32_t>(EM_AARCH64), regs.MachineType());
+
+  std::shared_ptr<Memory> process_memory(memory);
+
+  char* cwd = getcwd(nullptr, 0);
+  ASSERT_EQ(0, chdir(dir.c_str()));
+  Unwinder unwinder(128, &maps, &regs, process_memory);
+  unwinder.Unwind();
+  ASSERT_EQ(0, chdir(cwd));
+  free(cwd);
+
+  std::string frame_info(DumpFrames(unwinder));
+  ASSERT_EQ(6U, unwinder.NumFrames()) << "Unwind:\n" << frame_info;
+  EXPECT_EQ(
+      "  #00 pc 0000000000429fd8  libunwindstack_test (SignalInnerFunction+24)\n"
+      "  #01 pc 000000000042a078  libunwindstack_test (SignalMiddleFunction+8)\n"
+      "  #02 pc 000000000042a08c  libunwindstack_test (SignalOuterFunction+8)\n"
+      "  #03 pc 000000000042d8fc  libunwindstack_test "
+      "(_ZN11unwindstackL19RemoteThroughSignalEij+20)\n"
+      "  #04 pc 000000000042d8d8  libunwindstack_test "
+      "(_ZN11unwindstack37UnwindTest_remote_through_signal_Test8TestBodyEv+32)\n"
+      "  #05 pc 0000000000455d70  libunwindstack_test (_ZN7testing4Test3RunEv+392)\n",
+      frame_info);
+}
+
+}  // namespace unwindstack
diff --git a/libunwindstack/tests/UnwindTest.cpp b/libunwindstack/tests/UnwindTest.cpp
index 9f9ca8b..66c8ba6 100644
--- a/libunwindstack/tests/UnwindTest.cpp
+++ b/libunwindstack/tests/UnwindTest.cpp
@@ -311,4 +311,39 @@
   RemoteThroughSignal(SIGSEGV, SA_SIGINFO);
 }
 
+// Verify that using the same map while unwinding multiple threads at the
+// same time doesn't cause problems.
+TEST_F(UnwindTest, multiple_threads_unwind_same_map) {
+  static constexpr size_t kNumConcurrentThreads = 100;
+
+  LocalMaps maps;
+  ASSERT_TRUE(maps.Parse());
+  auto process_memory(Memory::CreateProcessMemory(getpid()));
+
+  std::vector<std::thread*> threads;
+
+  std::atomic_bool wait;
+  wait = true;
+  size_t frames[kNumConcurrentThreads];
+  for (size_t i = 0; i < kNumConcurrentThreads; i++) {
+    std::thread* thread = new std::thread([i, &frames, &maps, &process_memory, &wait]() {
+      while (wait)
+        ;
+      std::unique_ptr<Regs> regs(Regs::CreateFromLocal());
+      RegsGetLocal(regs.get());
+
+      Unwinder unwinder(512, &maps, regs.get(), process_memory);
+      unwinder.Unwind();
+      frames[i] = unwinder.NumFrames();
+      ASSERT_LE(3U, frames[i]) << "Failed for thread " << i;
+    });
+    threads.push_back(thread);
+  }
+  wait = false;
+  for (auto thread : threads) {
+    thread->join();
+    delete thread;
+  }
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/UnwinderTest.cpp b/libunwindstack/tests/UnwinderTest.cpp
index 869d118..098459e 100644
--- a/libunwindstack/tests/UnwinderTest.cpp
+++ b/libunwindstack/tests/UnwinderTest.cpp
@@ -45,82 +45,51 @@
 
   void FakeClear() { maps_.clear(); }
 
-  void FakeAddMapInfo(const MapInfo& map_info) { maps_.push_back(map_info); }
+  void FakeAddMapInfo(MapInfo* map_info) { maps_.push_back(map_info); }
 };
 
 class UnwinderTest : public ::testing::Test {
  protected:
   static void SetUpTestCase() {
     maps_.FakeClear();
-    MapInfo info;
-    info.name = "/system/fake/libc.so";
-    info.start = 0x1000;
-    info.end = 0x8000;
-    info.offset = 0;
-    info.flags = PROT_READ | PROT_WRITE;
+    MapInfo* info = new MapInfo(0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so");
     ElfFake* elf = new ElfFake(nullptr);
-    info.elf = elf;
+    info->elf = elf;
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
-    info.elf_offset = 0;
     maps_.FakeAddMapInfo(info);
 
-    info.name = "[stack]";
-    info.start = 0x10000;
-    info.end = 0x12000;
-    info.flags = PROT_READ | PROT_WRITE;
-    info.elf = nullptr;
+    info = new MapInfo(0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
     maps_.FakeAddMapInfo(info);
 
-    info.name = "/dev/fake_device";
-    info.start = 0x13000;
-    info.end = 0x15000;
-    info.flags = PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP;
-    info.elf = nullptr;
+    info = new MapInfo(0x13000, 0x15000, 0, PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP,
+                       "/dev/fake_device");
     maps_.FakeAddMapInfo(info);
 
-    info.name = "/system/fake/libunwind.so";
-    info.start = 0x20000;
-    info.end = 0x22000;
-    info.flags = PROT_READ | PROT_WRITE;
+    info = new MapInfo(0x20000, 0x22000, 0, PROT_READ | PROT_WRITE, "/system/fake/libunwind.so");
     elf = new ElfFake(nullptr);
-    info.elf = elf;
+    info->elf = elf;
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info.name = "/fake/libanother.so";
-    info.start = 0x23000;
-    info.end = 0x24000;
-    info.flags = PROT_READ | PROT_WRITE;
+    info = new MapInfo(0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so");
     elf = new ElfFake(nullptr);
-    info.elf = elf;
+    info->elf = elf;
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info.name = "/fake/compressed.so";
-    info.start = 0x33000;
-    info.end = 0x34000;
-    info.flags = PROT_READ | PROT_WRITE;
+    info = new MapInfo(0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so");
     elf = new ElfFake(nullptr);
-    info.elf = elf;
+    info->elf = elf;
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info.name = "/fake/fake.apk";
-    info.start = 0x43000;
-    info.end = 0x44000;
-    info.offset = 0x1d000;
-    info.flags = PROT_READ | PROT_WRITE;
+    info = new MapInfo(0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk");
     elf = new ElfFake(nullptr);
-    info.elf = elf;
+    info->elf = elf;
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info.name = "/fake/fake.oat";
-    info.start = 0x53000;
-    info.end = 0x54000;
-    info.offset = 0;
-    info.flags = PROT_READ | PROT_WRITE;
-    info.elf = nullptr;
+    info = new MapInfo(0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
     maps_.FakeAddMapInfo(info);
   }
 
diff --git a/libunwindstack/tests/files/offline/straddle_arm32/libbase.so b/libunwindstack/tests/files/offline/straddle_arm32/libbase.so
new file mode 100644
index 0000000..d1f16ee
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm32/libbase.so
Binary files differ
diff --git a/libunwindstack/tests/files/offline/straddle_arm32/libc.so b/libunwindstack/tests/files/offline/straddle_arm32/libc.so
new file mode 100644
index 0000000..4dc19ca
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm32/libc.so
Binary files differ
diff --git a/libunwindstack/tests/files/offline/straddle_arm32/maps.txt b/libunwindstack/tests/files/offline/straddle_arm32/maps.txt
new file mode 100644
index 0000000..8c26479
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm32/maps.txt
@@ -0,0 +1,4 @@
+f2d9a000-f2da7fff r-xp 00000000 00:00 0   libbase.so
+f3002000-f3005fff rw-p 00000000 00:00 0   [stack:25941]
+f31d0000-f326bfff r-xp 00000000 00:00 0   libc.so
+f3352000-f336bfff r-xp 00000000 00:00 0   /does/not/exist/libhidlbase.so
diff --git a/libunwindstack/tests/files/offline/straddle_arm32/regs.txt b/libunwindstack/tests/files/offline/straddle_arm32/regs.txt
new file mode 100644
index 0000000..3baedf3
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm32/regs.txt
@@ -0,0 +1,3 @@
+pc: f31ea9f8
+sp: e9c866f8
+lr: f31f179f
diff --git a/libunwindstack/tests/files/offline/straddle_arm32/stack.data b/libunwindstack/tests/files/offline/straddle_arm32/stack.data
new file mode 100644
index 0000000..83aeb4a
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm32/stack.data
Binary files differ
diff --git a/libunwindstack/tests/files/offline/straddle_arm64/libunwindstack_test b/libunwindstack/tests/files/offline/straddle_arm64/libunwindstack_test
new file mode 100644
index 0000000..092fc3a
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm64/libunwindstack_test
Binary files differ
diff --git a/libunwindstack/tests/files/offline/straddle_arm64/maps.txt b/libunwindstack/tests/files/offline/straddle_arm64/maps.txt
new file mode 100644
index 0000000..bdf29b5
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm64/maps.txt
@@ -0,0 +1,2 @@
+00000064d05ab000-00000064d0a6cfff r-xp 00000000 00:00 0  libunwindstack_test
+0000007fe0d64000-0000007fe0d84fff rw-p 00000000 00:00 0  [stack]
diff --git a/libunwindstack/tests/files/offline/straddle_arm64/regs.txt b/libunwindstack/tests/files/offline/straddle_arm64/regs.txt
new file mode 100644
index 0000000..ff8a936
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm64/regs.txt
@@ -0,0 +1,4 @@
+pc: 00000064d09d4fd8
+sp: 0000007fe0d84040
+lr: 00000064d09d507c
+x29: 0000007fe0d84070
diff --git a/libunwindstack/tests/files/offline/straddle_arm64/stack.data b/libunwindstack/tests/files/offline/straddle_arm64/stack.data
new file mode 100644
index 0000000..824d0e2
--- /dev/null
+++ b/libunwindstack/tests/files/offline/straddle_arm64/stack.data
Binary files differ
diff --git a/libunwindstack/tools/unwind_info.cpp b/libunwindstack/tools/unwind_info.cpp
index 77f3bb2..a00b2ee 100644
--- a/libunwindstack/tools/unwind_info.cpp
+++ b/libunwindstack/tools/unwind_info.cpp
@@ -19,6 +19,7 @@
 #include <fcntl.h>
 #include <inttypes.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
@@ -102,12 +103,12 @@
   }
 }
 
-int GetElfInfo(const char* file) {
+int GetElfInfo(const char* file, uint64_t offset) {
   // Send all log messages to stdout.
   log_to_stdout(true);
 
   MemoryFileAtOffset* memory = new MemoryFileAtOffset;
-  if (!memory->Init(file, 0)) {
+  if (!memory->Init(file, offset)) {
     // Initializatation failed.
     printf("Failed to init\n");
     return 1;
@@ -164,8 +165,12 @@
 }  // namespace unwindstack
 
 int main(int argc, char** argv) {
-  if (argc != 2) {
-    printf("Need to pass the name of an elf file to the program.\n");
+  if (argc != 2 && argc != 3) {
+    printf("Usage: unwind_info ELF_FILE [OFFSET]\n");
+    printf("  ELF_FILE\n");
+    printf("    The path to an elf file.\n");
+    printf("  OFFSET\n");
+    printf("    Use the offset into the ELF file as the beginning of the elf.\n");
     return 1;
   }
 
@@ -179,5 +184,15 @@
     return 1;
   }
 
-  return unwindstack::GetElfInfo(argv[1]);
+  uint64_t offset = 0;
+  if (argc == 3) {
+    char* end;
+    offset = strtoull(argv[2], &end, 16);
+    if (*end != '\0') {
+      printf("Malformed OFFSET value: %s\n", argv[2]);
+      return 1;
+    }
+  }
+
+  return unwindstack::GetElfInfo(argv[1], offset);
 }
diff --git a/libutils/include/utils/String16.h b/libutils/include/utils/String16.h
index cb3d338..15ed19f 100644
--- a/libutils/include/utils/String16.h
+++ b/libutils/include/utils/String16.h
@@ -35,9 +35,7 @@
 
 // ---------------------------------------------------------------------------
 
-class SharedBuffer;
 class String8;
-class TextOutput;
 
 //! This is a string holding UTF-16 characters.
 class String16
diff --git a/libutils/include/utils/String8.h b/libutils/include/utils/String8.h
index 1f3e5d8..0225c6b 100644
--- a/libutils/include/utils/String8.h
+++ b/libutils/include/utils/String8.h
@@ -31,7 +31,6 @@
 namespace android {
 
 class String16;
-class TextOutput;
 
 //! This is a string holding UTF-8 characters. Does not allow the value more
 // than 0x10FFFF, which is not valid unicode codepoint.
diff --git a/rootdir/Android.mk b/rootdir/Android.mk
index d4de0ba..aa970d6 100644
--- a/rootdir/Android.mk
+++ b/rootdir/Android.mk
@@ -257,3 +257,45 @@
 LOCAL_MODULE_STEM := $(LOCAL_MODULE)
 include $(BUILD_PREBUILT)
 endif
+
+#######################################
+# llndk.libraries.txt
+include $(CLEAR_VARS)
+LOCAL_MODULE := llndk.libraries.txt
+LOCAL_MODULE_CLASS := ETC
+LOCAL_MODULE_PATH := $(TARGET_OUT_ETC)
+LOCAL_MODULE_STEM := $(LOCAL_MODULE)
+include $(BUILD_SYSTEM)/base_rules.mk
+llndk_md5 = $(word 1, $(shell echo $(LLNDK_LIBRARIES) | $(MD5SUM)))
+llndk_dep = $(intermediates)/$(llndk_md5).dep
+$(llndk_dep):
+	$(hide) mkdir -p $(dir $@) && rm -rf $(dir $@)*.dep && touch $@
+
+$(LOCAL_BUILT_MODULE): PRIVATE_LLNDK_LIBRARIES := $(LLNDK_LIBRARIES)
+$(LOCAL_BUILT_MODULE): $(llndk_dep)
+	@echo "Generate: $@"
+	@mkdir -p $(dir $@)
+	$(hide) echo -n > $@
+	$(hide) $(foreach lib,$(PRIVATE_LLNDK_LIBRARIES), \
+		echo $(lib).so >> $@;)
+
+#######################################
+# vndksp.libraries.txt
+include $(CLEAR_VARS)
+LOCAL_MODULE := vndksp.libraries.txt
+LOCAL_MODULE_CLASS := ETC
+LOCAL_MODULE_PATH := $(TARGET_OUT_ETC)
+LOCAL_MODULE_STEM := $(LOCAL_MODULE)
+include $(BUILD_SYSTEM)/base_rules.mk
+vndksp_md5 = $(word 1, $(shell echo $(LLNDK_LIBRARIES) | $(MD5SUM)))
+vndksp_dep = $(intermediates)/$(vndksp_md5).dep
+$(vndksp_dep):
+	$(hide) mkdir -p $(dir $@) && rm -rf $(dir $@)*.dep && touch $@
+
+$(LOCAL_BUILT_MODULE): PRIVATE_VNDK_SAMEPROCESS_LIBRARIES := $(VNDK_SAMEPROCESS_LIBRARIES)
+$(LOCAL_BUILT_MODULE): $(vndksp_dep)
+	@echo "Generate: $@"
+	@mkdir -p $(dir $@)
+	$(hide) echo -n > $@
+	$(hide) $(foreach lib,$(PRIVATE_VNDK_SAMEPROCESS_LIBRARIES), \
+		echo $(lib).so >> $@;)
diff --git a/rootdir/etc/ld.config.txt.in b/rootdir/etc/ld.config.txt.in
index e741a34..a6bed8d 100644
--- a/rootdir/etc/ld.config.txt.in
+++ b/rootdir/etc/ld.config.txt.in
@@ -4,7 +4,7 @@
 #
 
 # Don't change the order here. The first pattern that matches with the
-# absolution path of an executable is selected.
+# absolute path of an executable is selected.
 dir.system = /system/bin/
 dir.system = /system/xbin/
 dir.vendor = /vendor/bin/
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 5d0e848..11b8383 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -433,6 +433,8 @@
     mkdir /data/misc/update_engine 0700 root root
     mkdir /data/misc/update_engine_log 02750 root log
     mkdir /data/misc/trace 0700 root root
+    # create location to store surface and window trace files
+    mkdir /data/misc/wmtrace 0700 system system
     # profile file layout
     mkdir /data/misc/profiles 0771 system system
     mkdir /data/misc/profiles/cur 0771 system system
@@ -731,6 +733,8 @@
     # Give writes to anyone for the trace folder on debug builds.
     # The folder is used to store method traces.
     chmod 0773 /data/misc/trace
+    # Give reads to anyone for the window trace folder on debug builds.
+    chmod 0775 /data/misc/wmtrace
     start console
 
 service flash_recovery /system/bin/install-recovery.sh
diff --git a/trusty/keymaster/trusty_keymaster_ipc.cpp b/trusty/keymaster/trusty_keymaster_ipc.cpp
index fbd0eb3..686e7ae 100644
--- a/trusty/keymaster/trusty_keymaster_ipc.cpp
+++ b/trusty/keymaster/trusty_keymaster_ipc.cpp
@@ -55,6 +55,11 @@
 
     size_t msg_size = in_size + sizeof(struct keymaster_message);
     struct keymaster_message* msg = reinterpret_cast<struct keymaster_message*>(malloc(msg_size));
+    if (!msg) {
+        ALOGE("failed to allocate msg buffer\n");
+        return -EINVAL;
+    }
+
     msg->cmd = cmd;
     memcpy(msg->payload, in, in_size);