diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index b971a9e..78f674c 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -57,6 +57,13 @@
         "Symbols.cpp",
     ],
 
+    target: {
+        // Always disable optimizations for host to make it easier to debug.
+        linux: {
+            cflags: ["-O0", "-g"],
+        },
+    },
+
     arch: {
         x86: {
             srcs: ["AsmGetRegsX86.S"],
@@ -97,7 +104,6 @@
         "tests/ElfTest.cpp",
         "tests/ElfTestUtils.cpp",
         "tests/LogFake.cpp",
-        "tests/MapInfoCreateMemoryTest.cpp",
         "tests/MapInfoGetElfTest.cpp",
         "tests/MapsTest.cpp",
         "tests/MemoryBufferTest.cpp",
diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index 3272215..96f2cb4 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <sys/mman.h>
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -76,40 +77,39 @@
   return memory.release();
 }
 
-Memory* MapInfo::CreateMemory(pid_t pid) {
+Memory* MapInfo::CreateMemory(const std::shared_ptr<Memory>& process_memory) {
   if (end <= start) {
     return nullptr;
   }
 
   elf_offset = 0;
 
+  // Fail on device maps.
+  if (flags & MAPS_FLAGS_DEVICE_MAP) {
+    return nullptr;
+  }
+
   // First try and use the file associated with the info.
   if (!name.empty()) {
-    // Fail on device maps.
-    if (flags & MAPS_FLAGS_DEVICE_MAP) {
-      return nullptr;
-    }
     Memory* memory = GetFileMemory();
     if (memory != nullptr) {
       return memory;
     }
   }
 
-  Memory* memory;
-  if (pid == getpid()) {
-    memory = new MemoryLocal();
-  } else {
-    memory = new MemoryRemote(pid);
+  // If the map isn't readable, don't bother trying to read from process memory.
+  if (!(flags & PROT_READ)) {
+    return nullptr;
   }
-  return new MemoryRange(memory, start, end);
+  return new MemoryRange(process_memory, start, end);
 }
 
-Elf* MapInfo::GetElf(pid_t pid, bool init_gnu_debugdata) {
+Elf* MapInfo::GetElf(const std::shared_ptr<Memory>& process_memory, bool init_gnu_debugdata) {
   if (elf) {
     return elf;
   }
 
-  elf = new Elf(CreateMemory(pid));
+  elf = new Elf(CreateMemory(process_memory));
   if (elf->Init() && init_gnu_debugdata) {
     elf->InitGnuDebugdata();
   }
diff --git a/libunwindstack/Memory.cpp b/libunwindstack/Memory.cpp
index 8c36055..32753df 100644
--- a/libunwindstack/Memory.cpp
+++ b/libunwindstack/Memory.cpp
@@ -52,6 +52,13 @@
   return false;
 }
 
+std::shared_ptr<Memory> Memory::CreateProcessMemory(pid_t pid) {
+  if (pid == getpid()) {
+    return std::shared_ptr<Memory>(new MemoryLocal());
+  }
+  return std::shared_ptr<Memory>(new MemoryRemote(pid));
+}
+
 bool MemoryBuffer::Read(uint64_t addr, void* dst, size_t size) {
   uint64_t last_read_byte;
   if (__builtin_add_overflow(size, addr, &last_read_byte)) {
@@ -249,7 +256,7 @@
   return true;
 }
 
-MemoryRange::MemoryRange(Memory* memory, uint64_t begin, uint64_t end)
+MemoryRange::MemoryRange(const std::shared_ptr<Memory>& memory, uint64_t begin, uint64_t end)
     : memory_(memory), begin_(begin), length_(end - begin) {
   CHECK(end > begin);
 }
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index b8ba925..f108766 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -40,10 +40,13 @@
   // instead of a portion of the file.
   uint64_t elf_offset;
 
-  Memory* GetFileMemory();
-  Memory* CreateMemory(pid_t pid);
   // This function guarantees it will never return nullptr.
-  Elf* GetElf(pid_t pid, bool init_gnu_debugdata = false);
+  Elf* GetElf(const std::shared_ptr<Memory>& process_memory, bool init_gnu_debugdata = false);
+
+ private:
+  Memory* GetFileMemory();
+
+  Memory* CreateMemory(const std::shared_ptr<Memory>& process_memory);
 };
 
 }  // namespace unwindstack
diff --git a/libunwindstack/include/unwindstack/Memory.h b/libunwindstack/include/unwindstack/Memory.h
index 0c05266..183b899 100644
--- a/libunwindstack/include/unwindstack/Memory.h
+++ b/libunwindstack/include/unwindstack/Memory.h
@@ -21,6 +21,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -31,6 +32,8 @@
   Memory() = default;
   virtual ~Memory() = default;
 
+  static std::shared_ptr<Memory> CreateProcessMemory(pid_t pid);
+
   virtual bool ReadString(uint64_t addr, std::string* string, uint64_t max_read = UINT64_MAX);
 
   virtual bool Read(uint64_t addr, void* dst, size_t size) = 0;
@@ -125,13 +128,13 @@
 
 class MemoryRange : public Memory {
  public:
-  MemoryRange(Memory* memory, uint64_t begin, uint64_t end);
-  virtual ~MemoryRange() { delete memory_; }
+  MemoryRange(const std::shared_ptr<Memory>& memory, uint64_t begin, uint64_t end);
+  virtual ~MemoryRange() = default;
 
   bool Read(uint64_t addr, void* dst, size_t size) override;
 
  private:
-  Memory* memory_;
+  std::shared_ptr<Memory> memory_;
   uint64_t begin_;
   uint64_t length_;
 };
diff --git a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
index 2aab9c6..d2aad49 100644
--- a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
+++ b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
@@ -34,6 +34,8 @@
 #include <unwindstack/MapInfo.h>
 #include <unwindstack/Memory.h>
 
+#include "MemoryFake.h"
+
 namespace unwindstack {
 
 class MapInfoCreateMemoryTest : public ::testing::Test {
@@ -71,6 +73,14 @@
     InitElf<Elf64_Ehdr, Elf64_Shdr>(elf64_at_map_.fd, 0x2000, 0x3000, ELFCLASS64);
   }
 
+  void SetUp() override {
+    memory_ = new MemoryFake;
+    process_memory_.reset(memory_);
+  }
+
+  MemoryFake* memory_;
+  std::shared_ptr<Memory> process_memory_;
+
   static TemporaryFile elf_;
 
   static TemporaryFile elf_at_100_;
@@ -86,17 +96,16 @@
 TEST_F(MapInfoCreateMemoryTest, end_le_start) {
   MapInfo info{.start = 0x100, .end = 0x100, .offset = 0, .name = elf_.path};
 
-  std::unique_ptr<Memory> memory;
-  memory.reset(info.CreateMemory(getpid()));
+  std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() == nullptr);
 
   info.end = 0xff;
-  memory.reset(info.CreateMemory(getpid()));
+  memory.reset(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() == nullptr);
 
   // Make sure this test is valid.
   info.end = 0x101;
-  memory.reset(info.CreateMemory(getpid()));
+  memory.reset(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
 }
 
@@ -105,7 +114,7 @@
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_full_file) {
   MapInfo info{.start = 0x100, .end = 0x200, .offset = 0x100, .name = elf_.path};
 
-  std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
+  std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0x100U, info.elf_offset);
 
@@ -126,7 +135,7 @@
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file) {
   MapInfo info{.start = 0x100, .end = 0x200, .offset = 0x100, .name = elf_at_100_.path};
 
-  std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
+  std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
 
@@ -149,7 +158,7 @@
 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};
 
-  std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
+  std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
 
@@ -165,7 +174,7 @@
 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};
 
-  std::unique_ptr<Memory> memory(info.CreateMemory(getpid()));
+  std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
   ASSERT_EQ(0U, info.elf_offset);
 
@@ -187,81 +196,38 @@
   info.start = reinterpret_cast<uint64_t>(buffer.data());
   info.end = info.start + buffer.size();
   info.offset = 0;
-  std::unique_ptr<Memory> memory;
 
   info.flags = 0x8000;
   info.name = "/dev/something";
-  memory.reset(info.CreateMemory(getpid()));
+  std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() == nullptr);
 }
 
-TEST_F(MapInfoCreateMemoryTest, local_memory) {
-  // Set up some memory for a valid local memory object.
+TEST_F(MapInfoCreateMemoryTest, process_memory) {
+  MapInfo info;
+  info.start = 0x2000;
+  info.end = 0x3000;
+  info.offset = 0;
+
+  // Verify that the the process_memory object is used, so seed it
+  // with memory.
   std::vector<uint8_t> buffer(1024);
   for (size_t i = 0; i < buffer.size(); i++) {
     buffer[i] = i % 256;
   }
+  memory_->SetMemory(info.start, buffer.data(), buffer.size());
 
-  MapInfo info;
-  info.start = reinterpret_cast<uint64_t>(buffer.data());
-  info.end = info.start + buffer.size();
-  info.offset = 0;
-
-  std::unique_ptr<Memory> memory;
-  memory.reset(info.CreateMemory(getpid()));
+  std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
 
-  std::vector<uint8_t> read_buffer(1024);
-  ASSERT_TRUE(memory->Read(0, read_buffer.data(), read_buffer.size()));
-  for (size_t i = 0; i < read_buffer.size(); i++) {
-    ASSERT_EQ(i % 256, read_buffer[i]) << "Failed at byte " << i;
+  memset(buffer.data(), 0, buffer.size());
+  ASSERT_TRUE(memory->Read(0, buffer.data(), buffer.size()));
+  for (size_t i = 0; i < buffer.size(); i++) {
+    ASSERT_EQ(i % 256, buffer[i]) << "Failed at byte " << i;
   }
 
-  ASSERT_FALSE(memory->Read(read_buffer.size(), read_buffer.data(), 1));
-}
-
-TEST_F(MapInfoCreateMemoryTest, remote_memory) {
-  std::vector<uint8_t> buffer(1024);
-  memset(buffer.data(), 0xa, buffer.size());
-
-  pid_t pid;
-  if ((pid = fork()) == 0) {
-    while (true)
-      ;
-    exit(1);
-  }
-  ASSERT_LT(0, pid);
-
-  ASSERT_TRUE(ptrace(PTRACE_ATTACH, pid, 0, 0) != -1);
-  uint64_t iterations = 0;
-  siginfo_t si;
-  while (TEMP_FAILURE_RETRY(ptrace(PTRACE_GETSIGINFO, pid, 0, &si)) < 0 && errno == ESRCH) {
-    usleep(30);
-    iterations++;
-    ASSERT_LT(iterations, 500000000ULL);
-  }
-
-  MapInfo info;
-  info.start = reinterpret_cast<uint64_t>(buffer.data());
-  info.end = info.start + buffer.size();
-  info.offset = 0;
-
-  std::unique_ptr<Memory> memory;
-  memory.reset(info.CreateMemory(pid));
-  ASSERT_TRUE(memory.get() != nullptr);
-  // Set the local memory to a different value to guarantee we are reading
-  // from the remote process.
-  memset(buffer.data(), 0x1, buffer.size());
-  std::vector<uint8_t> read_buffer(1024);
-  ASSERT_TRUE(memory->Read(0, read_buffer.data(), read_buffer.size()));
-  for (size_t i = 0; i < read_buffer.size(); i++) {
-    ASSERT_EQ(0xaU, read_buffer[i]) << "Failed at byte " << i;
-  }
-
-  ASSERT_TRUE(ptrace(PTRACE_DETACH, pid, 0, 0) == 0);
-
-  kill(pid, SIGKILL);
-  ASSERT_EQ(pid, wait(nullptr));
+  // Try to read outside of the map size.
+  ASSERT_FALSE(memory->Read(buffer.size(), buffer.data(), 1));
 }
 
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MapInfoGetElfTest.cpp b/libunwindstack/tests/MapInfoGetElfTest.cpp
index abfa172..0b70d13 100644
--- a/libunwindstack/tests/MapInfoGetElfTest.cpp
+++ b/libunwindstack/tests/MapInfoGetElfTest.cpp
@@ -32,43 +32,57 @@
 
 #include <unwindstack/Elf.h>
 #include <unwindstack/MapInfo.h>
+#include <unwindstack/Maps.h>
 #include <unwindstack/Memory.h>
 
 #include "ElfTestUtils.h"
+#include "MemoryFake.h"
 
 namespace unwindstack {
 
 class MapInfoGetElfTest : public ::testing::Test {
  protected:
   void SetUp() override {
-    map_ = mmap(nullptr, kMapSize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-    ASSERT_NE(MAP_FAILED, map_);
-
-    uint64_t start = reinterpret_cast<uint64_t>(map_);
-    info_.reset(new MapInfo{.start = start, .end = start + 1024, .offset = 0, .name = ""});
+    memory_ = new MemoryFake;
+    process_memory_.reset(memory_);
   }
 
-  void TearDown() override { munmap(map_, kMapSize); }
+  template <typename Ehdr, typename Shdr>
+  static void InitElf(uint64_t sh_offset, Ehdr* ehdr, uint8_t class_type, uint8_t machine_type) {
+    memset(ehdr, 0, sizeof(*ehdr));
+    memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
+    ehdr->e_ident[EI_CLASS] = class_type;
+    ehdr->e_machine = machine_type;
+    ehdr->e_shoff = sh_offset;
+    ehdr->e_shentsize = sizeof(Shdr) + 100;
+    ehdr->e_shnum = 4;
+  }
 
   const size_t kMapSize = 4096;
 
-  void* map_ = nullptr;
-  std::unique_ptr<MapInfo> info_;
+  std::shared_ptr<Memory> process_memory_;
+  MemoryFake* memory_;
+
+  TemporaryFile elf_;
 };
 
 TEST_F(MapInfoGetElfTest, invalid) {
+  MapInfo info{.start = 0x1000, .end = 0x2000, .offset = 0, .flags = PROT_READ, .name = ""};
+
   // The map is empty, but this should still create an invalid elf object.
-  std::unique_ptr<Elf> elf(info_->GetElf(getpid(), false));
+  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
   ASSERT_TRUE(elf.get() != nullptr);
   ASSERT_FALSE(elf->valid());
 }
 
 TEST_F(MapInfoGetElfTest, valid32) {
+  MapInfo info{.start = 0x3000, .end = 0x4000, .offset = 0, .flags = PROT_READ, .name = ""};
+
   Elf32_Ehdr ehdr;
   TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
-  memcpy(map_, &ehdr, sizeof(ehdr));
+  memory_->SetMemory(0x3000, &ehdr, sizeof(ehdr));
 
-  std::unique_ptr<Elf> elf(info_->GetElf(getpid(), false));
+  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
   ASSERT_TRUE(elf.get() != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
@@ -76,11 +90,13 @@
 }
 
 TEST_F(MapInfoGetElfTest, valid64) {
+  MapInfo info{.start = 0x8000, .end = 0x9000, .offset = 0, .flags = PROT_READ, .name = ""};
+
   Elf64_Ehdr ehdr;
   TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
-  memcpy(map_, &ehdr, sizeof(ehdr));
+  memory_->SetMemory(0x8000, &ehdr, sizeof(ehdr));
 
-  std::unique_ptr<Elf> elf(info_->GetElf(getpid(), false));
+  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
   ASSERT_TRUE(elf.get() != nullptr);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
@@ -88,12 +104,14 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_do_not_init32) {
-  TestInitGnuDebugdata<Elf32_Ehdr, Elf32_Shdr>(
-      ELFCLASS32, EM_ARM, false, [&](uint64_t offset, const void* ptr, size_t size) {
-        memcpy(&reinterpret_cast<uint8_t*>(map_)[offset], ptr, size);
-      });
+  MapInfo info{.start = 0x4000, .end = 0x8000, .offset = 0, .flags = PROT_READ, .name = ""};
 
-  std::unique_ptr<Elf> elf(info_->GetElf(getpid(), false));
+  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);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
@@ -102,12 +120,14 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_do_not_init64) {
-  TestInitGnuDebugdata<Elf64_Ehdr, Elf64_Shdr>(
-      ELFCLASS64, EM_AARCH64, false, [&](uint64_t offset, const void* ptr, size_t size) {
-        memcpy(&reinterpret_cast<uint8_t*>(map_)[offset], ptr, size);
-      });
+  MapInfo info{.start = 0x6000, .end = 0x8000, .offset = 0, .flags = PROT_READ, .name = ""};
 
-  std::unique_ptr<Elf> elf(info_->GetElf(getpid(), false));
+  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);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
@@ -116,12 +136,14 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_init32) {
-  TestInitGnuDebugdata<Elf32_Ehdr, Elf32_Shdr>(
-      ELFCLASS32, EM_ARM, true, [&](uint64_t offset, const void* ptr, size_t size) {
-        memcpy(&reinterpret_cast<uint8_t*>(map_)[offset], ptr, size);
-      });
+  MapInfo info{.start = 0x2000, .end = 0x3000, .offset = 0, .flags = PROT_READ, .name = ""};
 
-  std::unique_ptr<Elf> elf(info_->GetElf(getpid(), true));
+  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);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
@@ -130,12 +152,14 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_init64) {
-  TestInitGnuDebugdata<Elf64_Ehdr, Elf64_Shdr>(
-      ELFCLASS64, EM_AARCH64, true, [&](uint64_t offset, const void* ptr, size_t size) {
-        memcpy(&reinterpret_cast<uint8_t*>(map_)[offset], ptr, size);
-      });
+  MapInfo info{.start = 0x5000, .end = 0x8000, .offset = 0, .flags = PROT_READ, .name = ""};
 
-  std::unique_ptr<Elf> elf(info_->GetElf(getpid(), true));
+  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);
   ASSERT_TRUE(elf->valid());
   EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
@@ -143,4 +167,195 @@
   EXPECT_TRUE(elf->gnu_debugdata_interface() != nullptr);
 }
 
+TEST_F(MapInfoGetElfTest, end_le_start) {
+  MapInfo info{.start = 0x1000, .end = 0x1000, .offset = 0, .flags = PROT_READ, .name = 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));
+  ASSERT_FALSE(elf->valid());
+
+  info.elf = nullptr;
+  info.end = 0xfff;
+  elf.reset(info.GetElf(process_memory_, false));
+  ASSERT_FALSE(elf->valid());
+
+  // Make sure this test is valid.
+  info.elf = nullptr;
+  info.end = 0x2000;
+  elf.reset(info.GetElf(process_memory_, false));
+  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};
+
+  std::vector<uint8_t> buffer(0x1000);
+  memset(buffer.data(), 0, buffer.size());
+  Elf32_Ehdr ehdr;
+  TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
+  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));
+  ASSERT_TRUE(elf->valid());
+  ASSERT_TRUE(elf->memory() != nullptr);
+  ASSERT_EQ(0x100U, info.elf_offset);
+
+  // Read the entire file.
+  memset(buffer.data(), 0, buffer.size());
+  ASSERT_TRUE(elf->memory()->Read(0, buffer.data(), buffer.size()));
+  ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
+  for (size_t i = sizeof(ehdr); i < buffer.size(); i++) {
+    ASSERT_EQ(0, buffer[i]) << "Failed at byte " << i;
+  }
+
+  ASSERT_FALSE(elf->memory()->Read(buffer.size(), buffer.data(), 1));
+}
+
+// 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};
+
+  std::vector<uint8_t> buffer(0x4000);
+  memset(buffer.data(), 0, buffer.size());
+  Elf32_Ehdr ehdr;
+  TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
+  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));
+  ASSERT_TRUE(elf->valid());
+  ASSERT_TRUE(elf->memory() != nullptr);
+  ASSERT_EQ(0U, info.elf_offset);
+
+  // Read the valid part of the file.
+  ASSERT_TRUE(elf->memory()->Read(0, buffer.data(), 0x1000));
+  ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
+  for (size_t i = sizeof(ehdr); i < 0x1000; i++) {
+    ASSERT_EQ(0, buffer[i]) << "Failed at byte " << i;
+  }
+
+  ASSERT_FALSE(elf->memory()->Read(0x1000, buffer.data(), 1));
+}
+
+// Verify that if the offset is non-zero and there is an elf at that
+// offset, that only part of the file is used. Further verify that if the
+// 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};
+
+  std::vector<uint8_t> buffer(0x4000);
+  memset(buffer.data(), 0, buffer.size());
+  Elf32_Ehdr ehdr;
+  TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
+  ehdr.e_shoff = 0x2000;
+  ehdr.e_shentsize = sizeof(Elf32_Shdr) + 100;
+  ehdr.e_shnum = 4;
+  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));
+  ASSERT_TRUE(elf->valid());
+  ASSERT_TRUE(elf->memory() != nullptr);
+  ASSERT_EQ(0U, info.elf_offset);
+
+  // Verify the memory is a valid elf.
+  memset(buffer.data(), 0, buffer.size());
+  ASSERT_TRUE(elf->memory()->Read(0, buffer.data(), 0x1000));
+  ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
+
+  // Read past the end of what would normally be the size of the map.
+  ASSERT_TRUE(elf->memory()->Read(0x1000, buffer.data(), 1));
+}
+
+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};
+
+  std::vector<uint8_t> buffer(0x4000);
+  memset(buffer.data(), 0, buffer.size());
+  Elf64_Ehdr ehdr;
+  TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
+  ehdr.e_shoff = 0x2000;
+  ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
+  ehdr.e_shnum = 4;
+  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));
+  ASSERT_TRUE(elf->valid());
+  ASSERT_TRUE(elf->memory() != nullptr);
+  ASSERT_EQ(0U, info.elf_offset);
+
+  // Verify the memory is a valid elf.
+  memset(buffer.data(), 0, buffer.size());
+  ASSERT_TRUE(elf->memory()->Read(0, buffer.data(), 0x1000));
+  ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
+
+  // Read past the end of what would normally be the size of the map.
+  ASSERT_TRUE(elf->memory()->Read(0x1000, buffer.data(), 1));
+}
+
+TEST_F(MapInfoGetElfTest, process_memory_not_read_only) {
+  MapInfo info{.start = 0x9000, .end = 0xa000, .offset = 0x1000, .flags = 0, .name = ""};
+
+  // Create valid elf data in process memory only.
+  Elf64_Ehdr ehdr;
+  TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
+  ehdr.e_shoff = 0x2000;
+  ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
+  ehdr.e_shnum = 4;
+  memory_->SetMemory(0x9000, &ehdr, sizeof(ehdr));
+
+  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  ASSERT_FALSE(elf->valid());
+
+  info.elf = nullptr;
+  info.flags = PROT_READ;
+  elf.reset(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"};
+
+  // Create valid elf data in process memory for this to verify that only
+  // the name is causing invalid elf data.
+  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));
+
+  std::unique_ptr<Elf> elf(info.GetElf(process_memory_, false));
+  ASSERT_FALSE(elf->valid());
+
+  // Set the name to nothing to verify that it still fails.
+  info.elf = nullptr;
+  info.name = "";
+  elf.reset(info.GetElf(process_memory_, false));
+  ASSERT_FALSE(elf->valid());
+
+  // Change the flags and verify the elf is valid now.
+  info.elf = nullptr;
+  info.flags = PROT_READ;
+  elf.reset(info.GetElf(process_memory_, false));
+  ASSERT_TRUE(elf->valid());
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MemoryRangeTest.cpp b/libunwindstack/tests/MemoryRangeTest.cpp
index 6d1366c..680fae9 100644
--- a/libunwindstack/tests/MemoryRangeTest.cpp
+++ b/libunwindstack/tests/MemoryRangeTest.cpp
@@ -31,10 +31,11 @@
 TEST(MemoryRangeTest, read) {
   std::vector<uint8_t> src(1024);
   memset(src.data(), 0x4c, 1024);
-  MemoryFake* memory = new MemoryFake;
-  memory->SetMemory(9001, src);
+  MemoryFake* memory_fake = new MemoryFake;
+  std::shared_ptr<Memory> process_memory(memory_fake);
+  memory_fake->SetMemory(9001, src);
 
-  MemoryRange range(memory, 9001, 9001 + src.size());
+  MemoryRange range(process_memory, 9001, 9001 + src.size());
 
   std::vector<uint8_t> dst(1024);
   ASSERT_TRUE(range.Read(0, dst.data(), src.size()));
@@ -46,10 +47,11 @@
 TEST(MemoryRangeTest, read_near_limit) {
   std::vector<uint8_t> src(4096);
   memset(src.data(), 0x4c, 4096);
-  MemoryFake* memory = new MemoryFake;
-  memory->SetMemory(1000, src);
+  MemoryFake* memory_fake = new MemoryFake;
+  std::shared_ptr<Memory> process_memory(memory_fake);
+  memory_fake->SetMemory(1000, src);
 
-  MemoryRange range(memory, 1000, 2024);
+  MemoryRange range(process_memory, 1000, 2024);
 
   std::vector<uint8_t> dst(1024);
   ASSERT_TRUE(range.Read(1020, dst.data(), 4));
@@ -69,7 +71,8 @@
 TEST(MemoryRangeTest, read_overflow) {
   std::vector<uint8_t> buffer(100);
 
-  std::unique_ptr<MemoryRange> overflow(new MemoryRange(new MemoryFakeAlwaysReadZero, 100, 200));
+  std::shared_ptr<Memory> process_memory(new MemoryFakeAlwaysReadZero);
+  std::unique_ptr<MemoryRange> overflow(new MemoryRange(process_memory, 100, 200));
   ASSERT_FALSE(overflow->Read(UINT64_MAX - 10, buffer.data(), 100));
 }
 
diff --git a/libunwindstack/tests/UnwindTest.cpp b/libunwindstack/tests/UnwindTest.cpp
index 2fc3a38..a0c45bd 100644
--- a/libunwindstack/tests/UnwindTest.cpp
+++ b/libunwindstack/tests/UnwindTest.cpp
@@ -85,10 +85,11 @@
          function_names[index] + "\n" + "Unwind data:\n" + unwind_stream.str();
 }
 
-static void VerifyUnwind(pid_t pid, Memory* memory, Maps* maps, Regs* regs,
+static void VerifyUnwind(pid_t pid, Maps* maps, Regs* regs,
                          std::vector<const char*>& function_names) {
   size_t function_name_index = 0;
 
+  auto process_memory = Memory::CreateProcessMemory(pid);
   std::stringstream unwind_stream;
   unwind_stream << std::hex;
   for (size_t frame_num = 0; frame_num < 64; frame_num++) {
@@ -96,7 +97,7 @@
     MapInfo* map_info = maps->Find(regs->pc());
     ASSERT_TRUE(map_info != nullptr) << ErrorMsg(function_names, function_name_index, unwind_stream);
 
-    Elf* elf = map_info->GetElf(pid, true);
+    Elf* elf = map_info->GetElf(process_memory, true);
     uint64_t rel_pc = elf->GetRelPc(regs->pc(), map_info);
     uint64_t adjusted_rel_pc = rel_pc;
     if (frame_num != 0) {
@@ -122,7 +123,7 @@
       unwind_stream << " " << name;
     }
     unwind_stream << "\n";
-    ASSERT_TRUE(elf->Step(rel_pc + map_info->elf_offset, regs, memory))
+    ASSERT_TRUE(elf->Step(rel_pc + map_info->elf_offset, regs, process_memory.get()))
         << ErrorMsg(function_names, function_name_index, unwind_stream);
   }
   ASSERT_TRUE(false) << ErrorMsg(function_names, function_name_index, unwind_stream);
@@ -137,9 +138,8 @@
     ASSERT_TRUE(maps.Parse());
     std::unique_ptr<Regs> regs(Regs::CreateFromLocal());
     RegsGetLocal(regs.get());
-    MemoryLocal memory;
 
-    VerifyUnwind(getpid(), &memory, &maps, regs.get(), kFunctionOrder);
+    VerifyUnwind(getpid(), &maps, regs.get(), kFunctionOrder);
   } else {
     g_ready_for_remote = true;
     g_ready = true;
@@ -205,11 +205,10 @@
 
   RemoteMaps maps(pid);
   ASSERT_TRUE(maps.Parse());
-  MemoryRemote memory(pid);
   std::unique_ptr<Regs> regs(Regs::RemoteGet(pid));
   ASSERT_TRUE(regs.get() != nullptr);
 
-  VerifyUnwind(pid, &memory, &maps, regs.get(), kFunctionOrder);
+  VerifyUnwind(pid, &maps, regs.get(), kFunctionOrder);
 
   ASSERT_EQ(0, ptrace(PTRACE_DETACH, pid, 0, 0));
 
@@ -254,9 +253,8 @@
   LocalMaps maps;
   ASSERT_TRUE(maps.Parse());
   std::unique_ptr<Regs> regs(Regs::CreateFromUcontext(Regs::CurrentMachineType(), ucontext));
-  MemoryLocal memory;
 
-  VerifyUnwind(tid.load(), &memory, &maps, regs.get(), kFunctionOrder);
+  VerifyUnwind(getpid(), &maps, regs.get(), kFunctionOrder);
 
   ASSERT_EQ(0, sigaction(SIGUSR1, &oldact, nullptr));
 
@@ -291,11 +289,10 @@
 
   RemoteMaps maps(pid);
   ASSERT_TRUE(maps.Parse());
-  MemoryRemote memory(pid);
   std::unique_ptr<Regs> regs(Regs::RemoteGet(pid));
   ASSERT_TRUE(regs.get() != nullptr);
 
-  VerifyUnwind(pid, &memory, &maps, regs.get(), kFunctionSignalOrder);
+  VerifyUnwind(pid, &maps, regs.get(), kFunctionSignalOrder);
 
   ASSERT_EQ(0, ptrace(PTRACE_DETACH, pid, 0, 0));
 
diff --git a/libunwindstack/tools/unwind.cpp b/libunwindstack/tools/unwind.cpp
index c1077f8..3614198 100644
--- a/libunwindstack/tools/unwind.cpp
+++ b/libunwindstack/tools/unwind.cpp
@@ -91,7 +91,7 @@
   }
   printf("\n");
 
-  unwindstack::MemoryRemote remote_memory(pid);
+  auto process_memory = unwindstack::Memory::CreateProcessMemory(pid);
   for (size_t frame_num = 0; frame_num < 64; frame_num++) {
     if (regs->pc() == 0) {
       break;
@@ -102,7 +102,7 @@
       break;
     }
 
-    unwindstack::Elf* elf = map_info->GetElf(pid, true);
+    unwindstack::Elf* elf = map_info->GetElf(process_memory, true);
 
     uint64_t rel_pc = elf->GetRelPc(regs->pc(), map_info);
     uint64_t adjusted_rel_pc = rel_pc;
@@ -135,7 +135,7 @@
     }
     printf("\n");
 
-    if (!elf->Step(rel_pc + map_info->elf_offset, regs, &remote_memory)) {
+    if (!elf->Step(rel_pc + map_info->elf_offset, regs, process_memory.get())) {
       break;
     }
   }