Merge "Implement support for linker rosegment option."
diff --git a/libbacktrace/Android.bp b/libbacktrace/Android.bp
index 43bcd98..7f9a18a 100644
--- a/libbacktrace/Android.bp
+++ b/libbacktrace/Android.bp
@@ -116,10 +116,6 @@
 
     target: {
         linux_glibc: {
-            // The host uses rosegment, which isn't supported yet.
-            ldflags: [
-                "-Wl,--no-rosegment",
-            ],
             // This forces the creation of eh_frame with unwind information
             // for host.
             cflags: [
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index be2145d..970e05c 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -178,6 +178,7 @@
         "tests/JitDebugTest.cpp",
         "tests/LocalUnwinderTest.cpp",
         "tests/LogFake.cpp",
+        "tests/MapInfoCreateMemoryTest.cpp",
         "tests/MapInfoGetElfTest.cpp",
         "tests/MapInfoGetLoadBiasTest.cpp",
         "tests/MapsTest.cpp",
@@ -188,6 +189,7 @@
         "tests/MemoryOfflineBufferTest.cpp",
         "tests/MemoryOfflineTest.cpp",
         "tests/MemoryRangeTest.cpp",
+        "tests/MemoryRangesTest.cpp",
         "tests/MemoryRemoteTest.cpp",
         "tests/MemoryTest.cpp",
         "tests/RegsInfoTest.cpp",
diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index 39378a3..64005ae 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -102,7 +102,54 @@
   if (!(flags & PROT_READ)) {
     return nullptr;
   }
-  return new MemoryRange(process_memory, start, end - start, 0);
+
+  // Need to verify that this elf is valid. It's possible that
+  // only part of the elf file to be mapped into memory is in the executable
+  // map. In this case, there will be another read-only map that includes the
+  // first part of the elf file. This is done if the linker rosegment
+  // option is used.
+  std::unique_ptr<MemoryRange> memory(new MemoryRange(process_memory, start, end - start, 0));
+  bool valid;
+  uint64_t max_size;
+  Elf::GetInfo(memory.get(), &valid, &max_size);
+  if (valid) {
+    // Valid elf, we are done.
+    return memory.release();
+  }
+
+  if (name.empty() || maps_ == nullptr) {
+    return nullptr;
+  }
+
+  // Find the read-only map that has the same name and has an offset closest
+  // to the current offset but less than the offset of the current map.
+  // For shared libraries, there should be a r-x map that has a non-zero
+  // offset and then a r-- map that has a zero offset.
+  // For shared libraries loaded from an apk, there should be a r-x map that
+  // has a non-zero offset and then a r-- map that has a non-zero offset less
+  // than the offset from the r-x map.
+  uint64_t closest_offset = 0;
+  MapInfo* ro_map_info = nullptr;
+  for (auto map_info : *maps_) {
+    if (map_info->flags == PROT_READ && map_info->name == name && map_info->offset < offset &&
+        map_info->offset >= closest_offset) {
+      ro_map_info = map_info;
+      closest_offset = ro_map_info->offset;
+    }
+  }
+
+  if (ro_map_info != nullptr) {
+    // Make sure that relative pc values are corrected properly.
+    elf_offset = offset - closest_offset;
+
+    MemoryRanges* ranges = new MemoryRanges;
+    ranges->Insert(new MemoryRange(process_memory, ro_map_info->start,
+                                   ro_map_info->end - ro_map_info->start, 0));
+    ranges->Insert(new MemoryRange(process_memory, start, end - start, elf_offset));
+
+    return ranges;
+  }
+  return nullptr;
 }
 
 Elf* MapInfo::GetElf(const std::shared_ptr<Memory>& process_memory, bool init_gnu_debugdata) {
diff --git a/libunwindstack/Maps.cpp b/libunwindstack/Maps.cpp
index e676a5a..8729871 100644
--- a/libunwindstack/Maps.cpp
+++ b/libunwindstack/Maps.cpp
@@ -66,13 +66,13 @@
         if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
           flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
         }
-        maps_.push_back(new MapInfo(start, end, pgoff, flags, name));
+        maps_.push_back(new MapInfo(this, start, end, pgoff, flags, name));
       });
 }
 
 void Maps::Add(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
                const std::string& name, uint64_t load_bias) {
-  MapInfo* map_info = new MapInfo(start, end, offset, flags, name);
+  MapInfo* map_info = new MapInfo(this, start, end, offset, flags, name);
   map_info->load_bias = load_bias;
   maps_.push_back(map_info);
 }
@@ -97,7 +97,7 @@
         if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
           flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
         }
-        maps_.push_back(new MapInfo(start, end, pgoff, flags, name));
+        maps_.push_back(new MapInfo(this, start, end, pgoff, flags, name));
       });
 }
 
diff --git a/libunwindstack/Memory.cpp b/libunwindstack/Memory.cpp
index beb2aad..cfa8c6d 100644
--- a/libunwindstack/Memory.cpp
+++ b/libunwindstack/Memory.cpp
@@ -316,6 +316,18 @@
   return memory_->Read(read_addr, dst, read_length);
 }
 
+void MemoryRanges::Insert(MemoryRange* memory) {
+  maps_.emplace(memory->offset() + memory->length(), memory);
+}
+
+size_t MemoryRanges::Read(uint64_t addr, void* dst, size_t size) {
+  auto entry = maps_.upper_bound(addr);
+  if (entry != maps_.end()) {
+    return entry->second->Read(addr, dst, size);
+  }
+  return 0;
+}
+
 bool MemoryOffline::Init(const std::string& file, uint64_t offset) {
   auto memory_file = std::make_shared<MemoryFileAtOffset>();
   if (!memory_file->Init(file, offset)) {
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index ac0df41..9755c48 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -29,20 +29,25 @@
 namespace unwindstack {
 
 // Forward declarations.
+class Maps;
 class Memory;
 
 struct MapInfo {
-  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 char* name)
-      : start(start),
+  MapInfo(Maps* maps) : maps_(maps) {}
+  MapInfo(Maps* maps, uint64_t start, uint64_t end) : maps_(maps), start(start), end(end) {}
+  MapInfo(Maps* maps, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+          const char* name)
+      : maps_(maps),
+        start(start),
         end(end),
         offset(offset),
         flags(flags),
         name(name),
         load_bias(static_cast<uint64_t>(-1)) {}
-  MapInfo(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags, const std::string& name)
-      : start(start),
+  MapInfo(Maps* maps, uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
+          const std::string& name)
+      : maps_(maps),
+        start(start),
         end(end),
         offset(offset),
         flags(flags),
@@ -50,6 +55,8 @@
         load_bias(static_cast<uint64_t>(-1)) {}
   ~MapInfo() = default;
 
+  Maps* maps_ = nullptr;
+
   uint64_t start = 0;
   uint64_t end = 0;
   uint64_t offset = 0;
@@ -69,14 +76,14 @@
 
   uint64_t GetLoadBias(const std::shared_ptr<Memory>& process_memory);
 
+  Memory* CreateMemory(const std::shared_ptr<Memory>& process_memory);
+
  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_;
 };
diff --git a/libunwindstack/include/unwindstack/Memory.h b/libunwindstack/include/unwindstack/Memory.h
index dee5e98..9c425cb 100644
--- a/libunwindstack/include/unwindstack/Memory.h
+++ b/libunwindstack/include/unwindstack/Memory.h
@@ -22,6 +22,7 @@
 #include <unistd.h>
 
 #include <atomic>
+#include <map>
 #include <memory>
 #include <string>
 #include <vector>
@@ -119,6 +120,9 @@
 
   size_t Read(uint64_t addr, void* dst, size_t size) override;
 
+  uint64_t offset() { return offset_; }
+  uint64_t length() { return length_; }
+
  private:
   std::shared_ptr<Memory> memory_;
   uint64_t begin_;
@@ -126,6 +130,19 @@
   uint64_t offset_;
 };
 
+class MemoryRanges : public Memory {
+ public:
+  MemoryRanges() = default;
+  virtual ~MemoryRanges() = default;
+
+  void Insert(MemoryRange* memory);
+
+  size_t Read(uint64_t addr, void* dst, size_t size) override;
+
+ private:
+  std::map<uint64_t, std::unique_ptr<MemoryRange>> maps_;
+};
+
 class MemoryOffline : public Memory {
  public:
   MemoryOffline() = default;
diff --git a/libunwindstack/tests/DexFileTest.cpp b/libunwindstack/tests/DexFileTest.cpp
index 4dd8cb0..40f9f8e 100644
--- a/libunwindstack/tests/DexFileTest.cpp
+++ b/libunwindstack/tests/DexFileTest.cpp
@@ -120,7 +120,7 @@
             static_cast<size_t>(TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(kDexData)))));
 
   MemoryFake memory;
-  MapInfo info(0, 0x10000, 0, 0x5, tf.path);
+  MapInfo info(nullptr, 0, 0x10000, 0, 0x5, tf.path);
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x500, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 }
@@ -134,7 +134,7 @@
             static_cast<size_t>(TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(kDexData)))));
 
   MemoryFake memory;
-  MapInfo info(0x100, 0x10000, 0, 0x5, tf.path);
+  MapInfo info(nullptr, 0x100, 0x10000, 0, 0x5, tf.path);
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x600, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 }
@@ -148,7 +148,7 @@
             static_cast<size_t>(TEMP_FAILURE_RETRY(write(tf.fd, kDexData, sizeof(kDexData)))));
 
   MemoryFake memory;
-  MapInfo info(0x100, 0x10000, 0x200, 0x5, tf.path);
+  MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, tf.path);
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x400, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 }
@@ -156,7 +156,7 @@
 TEST(DexFileTest, create_using_memory_empty_file) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
-  MapInfo info(0x100, 0x10000, 0x200, 0x5, "");
+  MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "");
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 }
@@ -164,7 +164,7 @@
 TEST(DexFileTest, create_using_memory_file_does_not_exist) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
-  MapInfo info(0x100, 0x10000, 0x200, 0x5, "/does/not/exist");
+  MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "/does/not/exist");
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 }
@@ -178,7 +178,7 @@
 
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
-  MapInfo info(0x4000, 0x10000, 0x200, 0x5, "/does/not/exist");
+  MapInfo info(nullptr, 0x4000, 0x10000, 0x200, 0x5, "/does/not/exist");
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 
@@ -200,7 +200,7 @@
 TEST(DexFileTest, get_method) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
-  MapInfo info(0x100, 0x10000, 0x200, 0x5, "");
+  MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "");
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 
@@ -227,7 +227,7 @@
 TEST(DexFileTest, get_method_empty) {
   MemoryFake memory;
   memory.SetMemory(0x4000, kDexData, sizeof(kDexData));
-  MapInfo info(0x100, 0x10000, 0x200, 0x5, "");
+  MapInfo info(nullptr, 0x100, 0x10000, 0x200, 0x5, "");
   std::unique_ptr<DexFile> dex_file(DexFile::Create(0x4000, &memory, &info));
   ASSERT_TRUE(dex_file != nullptr);
 
diff --git a/libunwindstack/tests/ElfCacheTest.cpp b/libunwindstack/tests/ElfCacheTest.cpp
index 89331ea..1afd4ef 100644
--- a/libunwindstack/tests/ElfCacheTest.cpp
+++ b/libunwindstack/tests/ElfCacheTest.cpp
@@ -79,8 +79,8 @@
 
   uint64_t start = 0x1000;
   uint64_t end = 0x20000;
-  MapInfo info1(start, end, 0, 0x5, tf.path);
-  MapInfo info2(start, end, 0, 0x5, tf.path);
+  MapInfo info1(nullptr, start, end, 0, 0x5, tf.path);
+  MapInfo info2(nullptr, start, end, 0, 0x5, tf.path);
 
   Elf* elf1 = info1.GetElf(memory_, true);
   ASSERT_TRUE(elf1->valid());
@@ -120,17 +120,17 @@
   uint64_t start = 0x1000;
   uint64_t end = 0x20000;
   // Will have an elf at offset 0 in file.
-  MapInfo info0_1(start, end, 0, 0x5, tf.path);
-  MapInfo info0_2(start, end, 0, 0x5, tf.path);
+  MapInfo info0_1(nullptr, start, end, 0, 0x5, tf.path);
+  MapInfo info0_2(nullptr, start, end, 0, 0x5, tf.path);
   // Will have an elf at offset 0x100 in file.
-  MapInfo info100_1(start, end, 0x100, 0x5, tf.path);
-  MapInfo info100_2(start, end, 0x100, 0x5, tf.path);
+  MapInfo info100_1(nullptr, start, end, 0x100, 0x5, tf.path);
+  MapInfo info100_2(nullptr, start, end, 0x100, 0x5, tf.path);
   // Will have an elf at offset 0x200 in file.
-  MapInfo info200_1(start, end, 0x200, 0x5, tf.path);
-  MapInfo info200_2(start, end, 0x200, 0x5, tf.path);
+  MapInfo info200_1(nullptr, start, end, 0x200, 0x5, tf.path);
+  MapInfo info200_2(nullptr, start, end, 0x200, 0x5, tf.path);
   // Will have an elf at offset 0 in file.
-  MapInfo info300_1(start, end, 0x300, 0x5, tf.path);
-  MapInfo info300_2(start, end, 0x300, 0x5, tf.path);
+  MapInfo info300_1(nullptr, start, end, 0x300, 0x5, tf.path);
+  MapInfo info300_2(nullptr, start, end, 0x300, 0x5, tf.path);
 
   Elf* elf0_1 = info0_1.GetElf(memory_, true);
   ASSERT_TRUE(elf0_1->valid());
@@ -217,10 +217,10 @@
   uint64_t start = 0x1000;
   uint64_t end = 0x20000;
   // Multiple info sections at different offsets will have non-zero elf offsets.
-  MapInfo info300_1(start, end, 0x300, 0x5, tf.path);
-  MapInfo info300_2(start, end, 0x300, 0x5, tf.path);
-  MapInfo info400_1(start, end, 0x400, 0x5, tf.path);
-  MapInfo info400_2(start, end, 0x400, 0x5, tf.path);
+  MapInfo info300_1(nullptr, start, end, 0x300, 0x5, tf.path);
+  MapInfo info300_2(nullptr, start, end, 0x300, 0x5, tf.path);
+  MapInfo info400_1(nullptr, start, end, 0x400, 0x5, tf.path);
+  MapInfo info400_2(nullptr, start, end, 0x400, 0x5, tf.path);
 
   Elf* elf300_1 = info300_1.GetElf(memory_, true);
   ASSERT_TRUE(elf300_1->valid());
diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index 55fe16f..9a117b2 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -297,7 +297,7 @@
   elf.FakeSetInterface(interface);
 
   elf.FakeSetValid(true);
-  MapInfo map_info(0x1000, 0x2000);
+  MapInfo map_info(nullptr, 0x1000, 0x2000);
 
   ASSERT_EQ(0x101U, elf.GetRelPc(0x1101, &map_info));
 
diff --git a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
index 866b5b4..2a73c7e 100644
--- a/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
+++ b/libunwindstack/tests/MapInfoCreateMemoryTest.cpp
@@ -32,8 +32,10 @@
 
 #include <unwindstack/Elf.h>
 #include <unwindstack/MapInfo.h>
+#include <unwindstack/Maps.h>
 #include <unwindstack/Memory.h>
 
+#include "ElfTestUtils.h"
 #include "MemoryFake.h"
 
 namespace unwindstack {
@@ -94,7 +96,7 @@
 TemporaryFile MapInfoCreateMemoryTest::elf64_at_map_;
 
 TEST_F(MapInfoCreateMemoryTest, end_le_start) {
-  MapInfo info(0x100, 0x100, 0, 0, elf_.path);
+  MapInfo info(nullptr, 0x100, 0x100, 0, 0, elf_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() == nullptr);
@@ -112,7 +114,7 @@
 // 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(0x100, 0x200, 0x100, 0, elf_.path);
+  MapInfo info(nullptr, 0x100, 0x200, 0x100, 0, elf_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
@@ -133,7 +135,7 @@
 // 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(0x100, 0x200, 0x100, 0, elf_at_100_.path);
+  MapInfo info(nullptr, 0x100, 0x200, 0x100, 0, elf_at_100_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
@@ -156,7 +158,7 @@
 // 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(0x5000, 0x6000, 0x1000, 0, elf32_at_map_.path);
+  MapInfo info(nullptr, 0x5000, 0x6000, 0x1000, 0, elf32_at_map_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
@@ -172,7 +174,7 @@
 }
 
 TEST_F(MapInfoCreateMemoryTest, file_backed_non_zero_offset_partial_file_whole_elf64) {
-  MapInfo info(0x7000, 0x8000, 0x2000, 0, elf64_at_map_.path);
+  MapInfo info(nullptr, 0x7000, 0x8000, 0x2000, 0, elf64_at_map_.path);
 
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() != nullptr);
@@ -192,27 +194,24 @@
   // Set up some memory so that a valid local memory object would
   // be returned if the file mapping fails, but the device check is incorrect.
   std::vector<uint8_t> buffer(1024);
-  MapInfo info;
-  info.start = reinterpret_cast<uint64_t>(buffer.data());
-  info.end = info.start + buffer.size();
-  info.offset = 0;
+  uint64_t start = reinterpret_cast<uint64_t>(buffer.data());
+  MapInfo info(nullptr, start, start + buffer.size(), 0, 0x8000, "/dev/something");
 
-  info.flags = 0x8000;
-  info.name = "/dev/something";
   std::unique_ptr<Memory> memory(info.CreateMemory(process_memory_));
   ASSERT_TRUE(memory.get() == nullptr);
 }
 
 TEST_F(MapInfoCreateMemoryTest, process_memory) {
-  MapInfo info;
-  info.start = 0x2000;
-  info.end = 0x3000;
-  info.offset = 0;
+  MapInfo info(nullptr, 0x2000, 0x3000, 0, PROT_READ, "");
+
+  Elf32_Ehdr ehdr = {};
+  TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
+  std::vector<uint8_t> buffer(1024);
+  memcpy(buffer.data(), &ehdr, sizeof(ehdr));
 
   // 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++) {
+  for (size_t i = sizeof(ehdr); i < buffer.size(); i++) {
     buffer[i] = i % 256;
   }
   memory_->SetMemory(info.start, buffer.data(), buffer.size());
@@ -222,7 +221,8 @@
 
   memset(buffer.data(), 0, buffer.size());
   ASSERT_TRUE(memory->ReadFully(0, buffer.data(), buffer.size()));
-  for (size_t i = 0; i < buffer.size(); i++) {
+  ASSERT_EQ(0, memcmp(&ehdr, buffer.data(), sizeof(ehdr)));
+  for (size_t i = sizeof(ehdr); i < buffer.size(); i++) {
     ASSERT_EQ(i % 256, buffer[i]) << "Failed at byte " << i;
   }
 
@@ -230,4 +230,87 @@
   ASSERT_FALSE(memory->ReadFully(buffer.size(), buffer.data(), 1));
 }
 
+TEST_F(MapInfoCreateMemoryTest, valid_rosegment_zero_offset) {
+  Maps maps;
+  maps.Add(0x500, 0x600, 0, PROT_READ, "something_else", 0);
+  maps.Add(0x1000, 0x2600, 0, PROT_READ, "/only/in/memory.so", 0);
+  maps.Add(0x3000, 0x5000, 0x4000, PROT_READ | PROT_EXEC, "/only/in/memory.so", 0);
+
+  Elf32_Ehdr ehdr = {};
+  TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
+  memory_->SetMemory(0x1000, &ehdr, sizeof(ehdr));
+  memory_->SetMemoryBlock(0x1000 + sizeof(ehdr), 0x1600 - sizeof(ehdr), 0xab);
+
+  // Set the memory in the r-x map.
+  memory_->SetMemoryBlock(0x3000, 0x2000, 0x5d);
+
+  MapInfo* map_info = maps.Find(0x3000);
+  ASSERT_TRUE(map_info != nullptr);
+
+  std::unique_ptr<Memory> mem(map_info->CreateMemory(process_memory_));
+  ASSERT_TRUE(mem.get() != nullptr);
+  EXPECT_EQ(0x4000UL, map_info->elf_offset);
+  EXPECT_EQ(0x4000UL, map_info->offset);
+
+  // Verify that reading values from this memory works properly.
+  std::vector<uint8_t> buffer(0x4000);
+  size_t bytes = mem->Read(0, buffer.data(), buffer.size());
+  ASSERT_EQ(0x1600UL, bytes);
+  ASSERT_EQ(0, memcmp(&ehdr, buffer.data(), sizeof(ehdr)));
+  for (size_t i = sizeof(ehdr); i < bytes; i++) {
+    ASSERT_EQ(0xab, buffer[i]) << "Failed at byte " << i;
+  }
+
+  bytes = mem->Read(0x4000, buffer.data(), buffer.size());
+  ASSERT_EQ(0x2000UL, bytes);
+  for (size_t i = 0; i < bytes; i++) {
+    ASSERT_EQ(0x5d, buffer[i]) << "Failed at byte " << i;
+  }
+}
+
+TEST_F(MapInfoCreateMemoryTest, valid_rosegment_non_zero_offset) {
+  Maps maps;
+  maps.Add(0x500, 0x600, 0, PROT_READ, "something_else", 0);
+  maps.Add(0x1000, 0x2000, 0, PROT_READ, "/only/in/memory.apk", 0);
+  maps.Add(0x2000, 0x3000, 0x1000, PROT_READ | PROT_EXEC, "/only/in/memory.apk", 0);
+  maps.Add(0x3000, 0x4000, 0xa000, PROT_READ, "/only/in/memory.apk", 0);
+  maps.Add(0x4000, 0x5000, 0xb000, PROT_READ | PROT_EXEC, "/only/in/memory.apk", 0);
+
+  Elf32_Ehdr ehdr = {};
+  TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
+
+  // Setup an elf at offset 0x1000 in memory.
+  memory_->SetMemory(0x1000, &ehdr, sizeof(ehdr));
+  memory_->SetMemoryBlock(0x1000 + sizeof(ehdr), 0x2000 - sizeof(ehdr), 0x12);
+  memory_->SetMemoryBlock(0x2000, 0x1000, 0x23);
+
+  // Setup an elf at offset 0x3000 in memory..
+  memory_->SetMemory(0x3000, &ehdr, sizeof(ehdr));
+  memory_->SetMemoryBlock(0x3000 + sizeof(ehdr), 0x4000 - sizeof(ehdr), 0x34);
+  memory_->SetMemoryBlock(0x4000, 0x1000, 0x43);
+
+  MapInfo* map_info = maps.Find(0x4000);
+  ASSERT_TRUE(map_info != nullptr);
+
+  std::unique_ptr<Memory> mem(map_info->CreateMemory(process_memory_));
+  ASSERT_TRUE(mem.get() != nullptr);
+  EXPECT_EQ(0x1000UL, map_info->elf_offset);
+  EXPECT_EQ(0xb000UL, map_info->offset);
+
+  // Verify that reading values from this memory works properly.
+  std::vector<uint8_t> buffer(0x4000);
+  size_t bytes = mem->Read(0, buffer.data(), buffer.size());
+  ASSERT_EQ(0x1000UL, bytes);
+  ASSERT_EQ(0, memcmp(&ehdr, buffer.data(), sizeof(ehdr)));
+  for (size_t i = sizeof(ehdr); i < bytes; i++) {
+    ASSERT_EQ(0x34, buffer[i]) << "Failed at byte " << i;
+  }
+
+  bytes = mem->Read(0x1000, buffer.data(), buffer.size());
+  ASSERT_EQ(0x1000UL, bytes);
+  for (size_t i = 0; i < bytes; i++) {
+    ASSERT_EQ(0x43, buffer[i]) << "Failed at byte " << i;
+  }
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MapInfoGetElfTest.cpp b/libunwindstack/tests/MapInfoGetElfTest.cpp
index 861b82f..918c028 100644
--- a/libunwindstack/tests/MapInfoGetElfTest.cpp
+++ b/libunwindstack/tests/MapInfoGetElfTest.cpp
@@ -69,7 +69,7 @@
 };
 
 TEST_F(MapInfoGetElfTest, invalid) {
-  MapInfo info(0x1000, 0x2000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x1000, 0x2000, 0, PROT_READ, "");
 
   // The map is empty, but this should still create an invalid elf object.
   Elf* elf = info.GetElf(process_memory_, false);
@@ -78,7 +78,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, valid32) {
-  MapInfo info(0x3000, 0x4000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x3000, 0x4000, 0, PROT_READ, "");
 
   Elf32_Ehdr ehdr;
   TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
@@ -92,7 +92,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, valid64) {
-  MapInfo info(0x8000, 0x9000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x8000, 0x9000, 0, PROT_READ, "");
 
   Elf64_Ehdr ehdr;
   TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
@@ -106,7 +106,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_do_not_init32) {
-  MapInfo info(0x4000, 0x8000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x4000, 0x8000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf32_Ehdr, Elf32_Shdr>(ELFCLASS32, EM_ARM, false,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
@@ -122,7 +122,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_do_not_init64) {
-  MapInfo info(0x6000, 0x8000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x6000, 0x8000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf64_Ehdr, Elf64_Shdr>(ELFCLASS64, EM_AARCH64, false,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
@@ -138,7 +138,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_init32) {
-  MapInfo info(0x2000, 0x3000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x2000, 0x3000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf32_Ehdr, Elf32_Shdr>(ELFCLASS32, EM_ARM, true,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
@@ -154,7 +154,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, gnu_debugdata_init64) {
-  MapInfo info(0x5000, 0x8000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x5000, 0x8000, 0, PROT_READ, "");
 
   TestInitGnuDebugdata<Elf64_Ehdr, Elf64_Shdr>(ELFCLASS64, EM_AARCH64, true,
                                                [&](uint64_t offset, const void* ptr, size_t size) {
@@ -170,7 +170,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, end_le_start) {
-  MapInfo info(0x1000, 0x1000, 0, PROT_READ, elf_.path);
+  MapInfo info(nullptr, 0x1000, 0x1000, 0, PROT_READ, elf_.path);
 
   Elf32_Ehdr ehdr;
   TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
@@ -197,7 +197,7 @@
 // Verify that if the offset is non-zero but there is no elf at the offset,
 // that the full file is used.
 TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_full_file) {
-  MapInfo info(0x1000, 0x2000, 0x100, PROT_READ, elf_.path);
+  MapInfo info(nullptr, 0x1000, 0x2000, 0x100, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x1000);
   memset(buffer.data(), 0, buffer.size());
@@ -226,7 +226,7 @@
 // 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(0x1000, 0x2000, 0x2000, PROT_READ, elf_.path);
+  MapInfo info(nullptr, 0x1000, 0x2000, 0x2000, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x4000);
   memset(buffer.data(), 0, buffer.size());
@@ -256,7 +256,7 @@
 // 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(0x5000, 0x6000, 0x1000, PROT_READ, elf_.path);
+  MapInfo info(nullptr, 0x5000, 0x6000, 0x1000, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x4000);
   memset(buffer.data(), 0, buffer.size());
@@ -284,7 +284,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_partial_file_whole_elf64) {
-  MapInfo info(0x7000, 0x8000, 0x1000, PROT_READ, elf_.path);
+  MapInfo info(nullptr, 0x7000, 0x8000, 0x1000, PROT_READ, elf_.path);
 
   std::vector<uint8_t> buffer(0x4000);
   memset(buffer.data(), 0, buffer.size());
@@ -312,7 +312,7 @@
 }
 
 TEST_F(MapInfoGetElfTest, process_memory_not_read_only) {
-  MapInfo info(0x9000, 0xa000, 0x1000, 0, "");
+  MapInfo info(nullptr, 0x9000, 0xa000, 0x1000, 0, "");
 
   // Create valid elf data in process memory only.
   Elf64_Ehdr ehdr;
@@ -333,7 +333,8 @@
 }
 
 TEST_F(MapInfoGetElfTest, check_device_maps) {
-  MapInfo info(0x7000, 0x8000, 0x1000, PROT_READ | MAPS_FLAGS_DEVICE_MAP, "/dev/something");
+  MapInfo info(nullptr, 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.
@@ -378,7 +379,7 @@
   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, "");
+  MapInfo info(nullptr, 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)
diff --git a/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp b/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp
index 7e64a8a..f5ac6cb 100644
--- a/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp
+++ b/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp
@@ -50,7 +50,7 @@
     process_memory_.reset(memory_);
     elf_ = new ElfFake(new MemoryFake);
     elf_container_.reset(elf_);
-    map_info_.reset(new MapInfo(0x1000, 0x20000, 0, PROT_READ | PROT_WRITE, ""));
+    map_info_.reset(new MapInfo(nullptr, 0x1000, 0x20000, 0, PROT_READ | PROT_WRITE, ""));
   }
 
   void MultipleThreadTest(uint64_t expected_load_bias);
@@ -63,7 +63,7 @@
 };
 
 TEST_F(MapInfoGetLoadBiasTest, no_elf_and_no_valid_elf_in_memory) {
-  MapInfo info(0x1000, 0x2000, 0, PROT_READ, "");
+  MapInfo info(nullptr, 0x1000, 0x2000, 0, PROT_READ, "");
 
   EXPECT_EQ(0U, info.GetLoadBias(process_memory_));
 }
diff --git a/libunwindstack/tests/MapsTest.cpp b/libunwindstack/tests/MapsTest.cpp
index 9622ba5..6bdd0b2 100644
--- a/libunwindstack/tests/MapsTest.cpp
+++ b/libunwindstack/tests/MapsTest.cpp
@@ -63,7 +63,7 @@
 }
 
 TEST(MapsTest, verify_parse_line) {
-  MapInfo info;
+  MapInfo info(nullptr);
 
   VerifyLine("01-02 rwxp 03 04:05 06\n", &info);
   EXPECT_EQ(1U, info.start);
@@ -136,7 +136,7 @@
 }
 
 TEST(MapsTest, verify_large_values) {
-  MapInfo info;
+  MapInfo info(nullptr);
 #if defined(__LP64__)
   VerifyLine("fabcdef012345678-f12345678abcdef8 rwxp f0b0d0f010305070 00:00 0\n", &info);
   EXPECT_EQ(0xfabcdef012345678UL, info.start);
diff --git a/libunwindstack/tests/MemoryFake.cpp b/libunwindstack/tests/MemoryFake.cpp
index 60936cd..5695dfc 100644
--- a/libunwindstack/tests/MemoryFake.cpp
+++ b/libunwindstack/tests/MemoryFake.cpp
@@ -23,6 +23,17 @@
 
 namespace unwindstack {
 
+void MemoryFake::SetMemoryBlock(uint64_t addr, size_t length, uint8_t value) {
+  for (size_t i = 0; i < length; i++, addr++) {
+    auto entry = data_.find(addr);
+    if (entry != data_.end()) {
+      entry->second = value;
+    } else {
+      data_.insert({addr, value});
+    }
+  }
+}
+
 void MemoryFake::SetMemory(uint64_t addr, const void* memory, size_t length) {
   const uint8_t* src = reinterpret_cast<const uint8_t*>(memory);
   for (size_t i = 0; i < length; i++, addr++) {
diff --git a/libunwindstack/tests/MemoryFake.h b/libunwindstack/tests/MemoryFake.h
index 764a6c3..20610a5 100644
--- a/libunwindstack/tests/MemoryFake.h
+++ b/libunwindstack/tests/MemoryFake.h
@@ -36,6 +36,8 @@
 
   void SetMemory(uint64_t addr, const void* memory, size_t length);
 
+  void SetMemoryBlock(uint64_t addr, size_t length, uint8_t value);
+
   void SetData8(uint64_t addr, uint8_t value) {
     SetMemory(addr, &value, sizeof(value));
   }
diff --git a/libunwindstack/tests/MemoryRangeTest.cpp b/libunwindstack/tests/MemoryRangeTest.cpp
index cb1a0c9..2bac95b 100644
--- a/libunwindstack/tests/MemoryRangeTest.cpp
+++ b/libunwindstack/tests/MemoryRangeTest.cpp
@@ -15,7 +15,6 @@
  */
 
 #include <stdint.h>
-#include <string.h>
 
 #include <memory>
 #include <vector>
@@ -28,30 +27,34 @@
 
 namespace unwindstack {
 
-TEST(MemoryRangeTest, read) {
-  std::vector<uint8_t> src(1024);
-  memset(src.data(), 0x4c, 1024);
-  MemoryFake* memory_fake = new MemoryFake;
-  std::shared_ptr<Memory> process_memory(memory_fake);
-  memory_fake->SetMemory(9001, src);
+class MemoryRangeTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    process_memory_.reset();
+    memory_fake_ = new MemoryFake;
+    process_memory_.reset(memory_fake_);
+  }
 
-  MemoryRange range(process_memory, 9001, src.size(), 0);
+  std::shared_ptr<Memory> process_memory_;
+  MemoryFake* memory_fake_ = nullptr;
+};
+
+TEST_F(MemoryRangeTest, read_fully) {
+  memory_fake_->SetMemoryBlock(9000, 2048, 0x4c);
+
+  MemoryRange range(process_memory_, 9001, 1024, 0);
 
   std::vector<uint8_t> dst(1024);
-  ASSERT_TRUE(range.ReadFully(0, dst.data(), src.size()));
-  for (size_t i = 0; i < 1024; i++) {
+  ASSERT_TRUE(range.ReadFully(0, dst.data(), dst.size()));
+  for (size_t i = 0; i < dst.size(); i++) {
     ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
   }
 }
 
-TEST(MemoryRangeTest, read_near_limit) {
-  std::vector<uint8_t> src(4096);
-  memset(src.data(), 0x4c, 4096);
-  MemoryFake* memory_fake = new MemoryFake;
-  std::shared_ptr<Memory> process_memory(memory_fake);
-  memory_fake->SetMemory(1000, src);
+TEST_F(MemoryRangeTest, read_fully_near_limit) {
+  memory_fake_->SetMemoryBlock(0, 8192, 0x4c);
 
-  MemoryRange range(process_memory, 1000, 1024, 0);
+  MemoryRange range(process_memory_, 1000, 1024, 0);
 
   std::vector<uint8_t> dst(1024);
   ASSERT_TRUE(range.ReadFully(1020, dst.data(), 4));
@@ -68,7 +71,7 @@
   ASSERT_TRUE(range.ReadFully(1020, dst.data(), 4));
 }
 
-TEST(MemoryRangeTest, read_overflow) {
+TEST_F(MemoryRangeTest, read_fully_overflow) {
   std::vector<uint8_t> buffer(100);
 
   std::shared_ptr<Memory> process_memory(new MemoryFakeAlwaysReadZero);
@@ -76,19 +79,28 @@
   ASSERT_FALSE(overflow->ReadFully(UINT64_MAX - 10, buffer.data(), 100));
 }
 
-TEST(MemoryRangeTest, Read) {
-  std::vector<uint8_t> src(4096);
-  memset(src.data(), 0x4c, 4096);
-  MemoryFake* memory_fake = new MemoryFake;
-  std::shared_ptr<Memory> process_memory(memory_fake);
-  memory_fake->SetMemory(1000, src);
+TEST_F(MemoryRangeTest, read) {
+  memory_fake_->SetMemoryBlock(0, 4096, 0x4c);
 
-  MemoryRange range(process_memory, 1000, 1024, 0);
+  MemoryRange range(process_memory_, 1000, 1024, 0);
+
   std::vector<uint8_t> dst(1024);
-  ASSERT_EQ(4U, range.Read(1020, dst.data(), 1024));
+  ASSERT_EQ(4U, range.Read(1020, dst.data(), dst.size()));
   for (size_t i = 0; i < 4; i++) {
     ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
   }
 }
 
+TEST_F(MemoryRangeTest, read_non_zero_offset) {
+  memory_fake_->SetMemoryBlock(1000, 1024, 0x12);
+
+  MemoryRange range(process_memory_, 1000, 1024, 400);
+
+  std::vector<uint8_t> dst(1024);
+  ASSERT_EQ(1024U, range.Read(400, dst.data(), dst.size()));
+  for (size_t i = 0; i < dst.size(); i++) {
+    ASSERT_EQ(0x12U, dst[i]) << "Failed at byte " << i;
+  }
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MemoryRangesTest.cpp b/libunwindstack/tests/MemoryRangesTest.cpp
new file mode 100644
index 0000000..d24fcd2
--- /dev/null
+++ b/libunwindstack/tests/MemoryRangesTest.cpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+
+#include <vector>
+
+#include <gtest/gtest.h>
+
+#include <unwindstack/Memory.h>
+
+#include "MemoryFake.h"
+
+namespace unwindstack {
+
+class MemoryRangesTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    MemoryFake* memory = new MemoryFake;
+    process_memory_.reset(memory);
+    memory->SetMemoryBlock(1000, 5000, 0x15);
+    memory->SetMemoryBlock(6000, 12000, 0x26);
+    memory->SetMemoryBlock(14000, 20000, 0x37);
+    memory->SetMemoryBlock(20000, 22000, 0x48);
+
+    ranges_.reset(new MemoryRanges);
+    ranges_->Insert(new MemoryRange(process_memory_, 15000, 100, 4000));
+    ranges_->Insert(new MemoryRange(process_memory_, 10000, 2000, 2000));
+    ranges_->Insert(new MemoryRange(process_memory_, 3000, 1000, 0));
+    ranges_->Insert(new MemoryRange(process_memory_, 19000, 1000, 6000));
+    ranges_->Insert(new MemoryRange(process_memory_, 20000, 1000, 7000));
+  }
+
+  std::shared_ptr<Memory> process_memory_;
+  std::unique_ptr<MemoryRanges> ranges_;
+};
+
+TEST_F(MemoryRangesTest, read) {
+  std::vector<uint8_t> dst(2000);
+  size_t bytes = ranges_->Read(0, dst.data(), dst.size());
+  ASSERT_EQ(1000UL, bytes);
+  for (size_t i = 0; i < bytes; i++) {
+    ASSERT_EQ(0x15U, dst[i]) << "Failed at byte " << i;
+  }
+
+  bytes = ranges_->Read(2000, dst.data(), dst.size());
+  ASSERT_EQ(2000UL, bytes);
+  for (size_t i = 0; i < bytes; i++) {
+    ASSERT_EQ(0x26U, dst[i]) << "Failed at byte " << i;
+  }
+
+  bytes = ranges_->Read(4000, dst.data(), dst.size());
+  ASSERT_EQ(100UL, bytes);
+  for (size_t i = 0; i < bytes; i++) {
+    ASSERT_EQ(0x37U, dst[i]) << "Failed at byte " << i;
+  }
+}
+
+TEST_F(MemoryRangesTest, read_fail) {
+  std::vector<uint8_t> dst(4096);
+  ASSERT_EQ(0UL, ranges_->Read(1000, dst.data(), dst.size()));
+  ASSERT_EQ(0UL, ranges_->Read(5000, dst.data(), dst.size()));
+  ASSERT_EQ(0UL, ranges_->Read(8000, dst.data(), dst.size()));
+}
+
+TEST_F(MemoryRangesTest, read_across_ranges) {
+  // The MemoryRanges object does not support reading across a range,
+  // so this will only read in the first range.
+  std::vector<uint8_t> dst(4096);
+  size_t bytes = ranges_->Read(6000, dst.data(), dst.size());
+  ASSERT_EQ(1000UL, bytes);
+  for (size_t i = 0; i < bytes; i++) {
+    ASSERT_EQ(0x37U, dst[i]) << "Failed at byte " << i;
+  }
+}
+
+}  // namespace unwindstack
diff --git a/libunwindstack/tests/RegsTest.cpp b/libunwindstack/tests/RegsTest.cpp
index 90c3fe6..00264c2 100644
--- a/libunwindstack/tests/RegsTest.cpp
+++ b/libunwindstack/tests/RegsTest.cpp
@@ -182,7 +182,7 @@
   RegsX86_64 regs_x86_64;
   RegsMips regs_mips;
   RegsMips64 regs_mips64;
-  MapInfo map_info(0x1000, 0x2000);
+  MapInfo map_info(nullptr, 0x1000, 0x2000);
   Elf* invalid_elf = new Elf(nullptr);
   map_info.elf.reset(invalid_elf);
 
diff --git a/libunwindstack/tests/UnwinderTest.cpp b/libunwindstack/tests/UnwinderTest.cpp
index 2428f68..4369030 100644
--- a/libunwindstack/tests/UnwinderTest.cpp
+++ b/libunwindstack/tests/UnwinderTest.cpp
@@ -58,51 +58,54 @@
  protected:
   static void SetUpTestCase() {
     maps_.FakeClear();
-    MapInfo* info = new MapInfo(0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so");
+    MapInfo* info =
+        new MapInfo(&maps_, 0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so");
     ElfFake* elf = new ElfFake(new MemoryFake);
     info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
+    info = new MapInfo(&maps_, 0x10000, 0x12000, 0, PROT_READ | PROT_WRITE, "[stack]");
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0x13000, 0x15000, 0, PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP,
+    info = new MapInfo(&maps_, 0x13000, 0x15000, 0, PROT_READ | PROT_WRITE | MAPS_FLAGS_DEVICE_MAP,
                        "/dev/fake_device");
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0x20000, 0x22000, 0, PROT_READ | PROT_WRITE, "/system/fake/libunwind.so");
+    info = new MapInfo(&maps_, 0x20000, 0x22000, 0, PROT_READ | PROT_WRITE,
+                       "/system/fake/libunwind.so");
     elf = new ElfFake(new MemoryFake);
     info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so");
+    info = new MapInfo(&maps_, 0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so");
     elf = new ElfFake(new MemoryFake);
     info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so");
+    info = new MapInfo(&maps_, 0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so");
     elf = new ElfFake(new MemoryFake);
     info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk");
+    info = new MapInfo(&maps_, 0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk");
     elf = new ElfFake(new MemoryFake);
     info->elf.reset(elf);
     elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
+    info = new MapInfo(&maps_, 0x53000, 0x54000, 0, PROT_READ | PROT_WRITE, "/fake/fake.oat");
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC, "/fake/fake.vdex");
+    info = new MapInfo(&maps_, 0xa3000, 0xa4000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
+                       "/fake/fake.vdex");
     info->load_bias = 0;
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0xa5000, 0xa6000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
+    info = new MapInfo(&maps_, 0xa5000, 0xa6000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
                        "/fake/fake_load_bias.so");
     elf = new ElfFake(new MemoryFake);
     info->elf.reset(elf);
@@ -110,7 +113,7 @@
     elf->FakeSetLoadBias(0x5000);
     maps_.FakeAddMapInfo(info);
 
-    info = new MapInfo(0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
+    info = new MapInfo(&maps_, 0xa7000, 0xa8000, 0, PROT_READ | PROT_WRITE | PROT_EXEC,
                        "/fake/fake_offset.oat");
     elf = new ElfFake(new MemoryFake);
     info->elf.reset(elf);