diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index 140d05a..6239c81 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -101,7 +101,7 @@
   if (!(flags & PROT_READ)) {
     return nullptr;
   }
-  return new MemoryRange(process_memory, start, end);
+  return new MemoryRange(process_memory, start, end - start, 0);
 }
 
 Elf* MapInfo::GetElf(const std::shared_ptr<Memory>& process_memory, bool init_gnu_debugdata) {
diff --git a/libunwindstack/Memory.cpp b/libunwindstack/Memory.cpp
index 32753df..f27a350 100644
--- a/libunwindstack/Memory.cpp
+++ b/libunwindstack/Memory.cpp
@@ -32,8 +32,63 @@
 
 #include "Check.h"
 
+static size_t ProcessVmRead(pid_t pid, void* dst, uint64_t remote_src, size_t len) {
+  struct iovec dst_iov = {
+      .iov_base = dst,
+      .iov_len = len,
+  };
+
+  // Split up the remote read across page boundaries.
+  // From the manpage:
+  //   A partial read/write may result if one of the remote_iov elements points to an invalid
+  //   memory region in the remote process.
+  //
+  //   Partial transfers apply at the granularity of iovec elements.  These system calls won't
+  //   perform a partial transfer that splits a single iovec element.
+  constexpr size_t kMaxIovecs = 64;
+  struct iovec src_iovs[kMaxIovecs];
+  size_t iovecs_used = 0;
+
+  uint64_t cur = remote_src;
+  while (len > 0) {
+    if (iovecs_used == kMaxIovecs) {
+      errno = EINVAL;
+      return 0;
+    }
+
+    // struct iovec uses void* for iov_base.
+    if (cur >= UINTPTR_MAX) {
+      errno = EFAULT;
+      return 0;
+    }
+
+    src_iovs[iovecs_used].iov_base = reinterpret_cast<void*>(cur);
+
+    uintptr_t misalignment = cur & (getpagesize() - 1);
+    size_t iov_len = getpagesize() - misalignment;
+    iov_len = std::min(iov_len, len);
+
+    len -= iov_len;
+    if (__builtin_add_overflow(cur, iov_len, &cur)) {
+      errno = EFAULT;
+      return 0;
+    }
+
+    src_iovs[iovecs_used].iov_len = iov_len;
+    ++iovecs_used;
+  }
+
+  ssize_t rc = process_vm_readv(pid, &dst_iov, 1, src_iovs, iovecs_used, 0);
+  return rc == -1 ? 0 : rc;
+}
+
 namespace unwindstack {
 
+bool Memory::Read(uint64_t addr, void* dst, size_t size) {
+  size_t rc = ReadPartially(addr, dst, size);
+  return rc == size;
+}
+
 bool Memory::ReadString(uint64_t addr, std::string* string, uint64_t max_read) {
   string->clear();
   uint64_t bytes_read = 0;
@@ -59,16 +114,17 @@
   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)) {
-    return false;
+size_t MemoryBuffer::ReadPartially(uint64_t addr, void* dst, size_t size) {
+  if (addr >= raw_.size()) {
+    return 0;
   }
-  if (last_read_byte > raw_.size()) {
-    return false;
-  }
-  memcpy(dst, &raw_[addr], size);
-  return true;
+
+  size_t bytes_left = raw_.size() - static_cast<size_t>(addr);
+  const unsigned char* actual_base = static_cast<const unsigned char*>(raw_.data()) + addr;
+  size_t actual_len = std::min(bytes_left, size);
+
+  memcpy(dst, actual_base, actual_len);
+  return actual_len;
 }
 
 uint8_t* MemoryBuffer::GetPtr(size_t offset) {
@@ -129,145 +185,77 @@
   return true;
 }
 
-bool MemoryFileAtOffset::Read(uint64_t addr, void* dst, size_t size) {
-  uint64_t max_size;
-  if (__builtin_add_overflow(addr, size, &max_size) || max_size > size_) {
-    return false;
+size_t MemoryFileAtOffset::ReadPartially(uint64_t addr, void* dst, size_t size) {
+  if (addr >= size_) {
+    return 0;
   }
-  memcpy(dst, &data_[addr], size);
-  return true;
+
+  size_t bytes_left = size_ - static_cast<size_t>(addr);
+  const unsigned char* actual_base = static_cast<const unsigned char*>(data_) + addr;
+  size_t actual_len = std::min(bytes_left, size);
+
+  memcpy(dst, actual_base, actual_len);
+  return actual_len;
 }
 
-bool MemoryRemote::PtraceRead(uint64_t addr, long* value) {
-#if !defined(__LP64__)
-  // Cannot read an address greater than 32 bits.
-  if (addr > UINT32_MAX) {
-    return false;
-  }
-#endif
-  // ptrace() returns -1 and sets errno when the operation fails.
-  // To disambiguate -1 from a valid result, we clear errno beforehand.
-  errno = 0;
-  *value = ptrace(PTRACE_PEEKTEXT, pid_, reinterpret_cast<void*>(addr), nullptr);
-  if (*value == -1 && errno) {
-    return false;
-  }
-  return true;
+size_t MemoryRemote::ReadPartially(uint64_t addr, void* dst, size_t size) {
+  return ProcessVmRead(pid_, dst, addr, size);
 }
 
-bool MemoryRemote::Read(uint64_t addr, void* dst, size_t bytes) {
-  // Make sure that there is no overflow.
-  uint64_t max_size;
-  if (__builtin_add_overflow(addr, bytes, &max_size)) {
-    return false;
-  }
-
-  size_t bytes_read = 0;
-  long data;
-  size_t align_bytes = addr & (sizeof(long) - 1);
-  if (align_bytes != 0) {
-    if (!PtraceRead(addr & ~(sizeof(long) - 1), &data)) {
-      return false;
-    }
-    size_t copy_bytes = std::min(sizeof(long) - align_bytes, bytes);
-    memcpy(dst, reinterpret_cast<uint8_t*>(&data) + align_bytes, copy_bytes);
-    addr += copy_bytes;
-    dst = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(dst) + copy_bytes);
-    bytes -= copy_bytes;
-    bytes_read += copy_bytes;
-  }
-
-  for (size_t i = 0; i < bytes / sizeof(long); i++) {
-    if (!PtraceRead(addr, &data)) {
-      return false;
-    }
-    memcpy(dst, &data, sizeof(long));
-    dst = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(dst) + sizeof(long));
-    addr += sizeof(long);
-    bytes_read += sizeof(long);
-  }
-
-  size_t left_over = bytes & (sizeof(long) - 1);
-  if (left_over) {
-    if (!PtraceRead(addr, &data)) {
-      return false;
-    }
-    memcpy(dst, &data, left_over);
-    bytes_read += left_over;
-  }
-  return true;
+size_t MemoryLocal::ReadPartially(uint64_t addr, void* dst, size_t size) {
+  return ProcessVmRead(getpid(), dst, addr, size);
 }
 
-bool MemoryLocal::Read(uint64_t addr, void* dst, size_t size) {
-  // Make sure that there is no overflow.
-  uint64_t max_size;
-  if (__builtin_add_overflow(addr, size, &max_size)) {
-    return false;
+MemoryRange::MemoryRange(const std::shared_ptr<Memory>& memory, uint64_t begin, uint64_t length,
+                         uint64_t offset)
+    : memory_(memory), begin_(begin), length_(length), offset_(offset) {}
+
+size_t MemoryRange::ReadPartially(uint64_t addr, void* dst, size_t size) {
+  if (addr < offset_) {
+    return 0;
   }
 
-  // The process_vm_readv call will not always work on remote
-  // processes, so only use it for reads from the current pid.
-  // Use this method to avoid crashes if an address is invalid since
-  // unwind data could try to access any part of the address space.
-  struct iovec local_io;
-  local_io.iov_base = dst;
-  local_io.iov_len = size;
-
-  struct iovec remote_io;
-  remote_io.iov_base = reinterpret_cast<void*>(static_cast<uintptr_t>(addr));
-  remote_io.iov_len = size;
-
-  ssize_t bytes_read = process_vm_readv(getpid(), &local_io, 1, &remote_io, 1, 0);
-  if (bytes_read == -1) {
-    return false;
+  uint64_t read_offset = addr - offset_;
+  if (read_offset >= length_) {
+    return 0;
   }
-  return static_cast<size_t>(bytes_read) == size;
+
+  uint64_t read_length = std::min(static_cast<uint64_t>(size), length_ - read_offset);
+  uint64_t read_addr;
+  if (__builtin_add_overflow(read_offset, begin_, &read_addr)) {
+    return 0;
+  }
+
+  return memory_->ReadPartially(read_addr, dst, read_length);
 }
 
 bool MemoryOffline::Init(const std::string& file, uint64_t offset) {
-  if (!MemoryFileAtOffset::Init(file, offset)) {
+  auto memory_file = std::make_shared<MemoryFileAtOffset>();
+  if (!memory_file->Init(file, offset)) {
     return false;
   }
+
   // The first uint64_t value is the start of memory.
-  if (!MemoryFileAtOffset::Read(0, &start_, sizeof(start_))) {
+  uint64_t start;
+  if (!memory_file->Read(0, &start, sizeof(start))) {
     return false;
   }
-  // Subtract the first 64 bit value from the total size.
-  size_ -= sizeof(start_);
+
+  uint64_t size = memory_file->Size();
+  if (__builtin_sub_overflow(size, sizeof(start), &size)) {
+    return false;
+  }
+
+  memory_ = std::make_unique<MemoryRange>(memory_file, sizeof(start), size, start);
   return true;
 }
 
-bool MemoryOffline::Read(uint64_t addr, void* dst, size_t size) {
-  uint64_t max_size;
-  if (__builtin_add_overflow(addr, size, &max_size)) {
-    return false;
+size_t MemoryOffline::ReadPartially(uint64_t addr, void* dst, size_t size) {
+  if (!memory_) {
+    return 0;
   }
 
-  uint64_t real_size;
-  if (__builtin_add_overflow(start_, offset_, &real_size) ||
-      __builtin_add_overflow(real_size, size_, &real_size)) {
-    return false;
-  }
-
-  if (addr < start_ || max_size > real_size) {
-    return false;
-  }
-  memcpy(dst, &data_[addr + offset_ - start_ + sizeof(start_)], size);
-  return true;
-}
-
-MemoryRange::MemoryRange(const std::shared_ptr<Memory>& memory, uint64_t begin, uint64_t end)
-    : memory_(memory), begin_(begin), length_(end - begin) {
-  CHECK(end > begin);
-}
-
-bool MemoryRange::Read(uint64_t addr, void* dst, size_t size) {
-  uint64_t max_read;
-  if (__builtin_add_overflow(addr, size, &max_read) || max_read > length_) {
-    return false;
-  }
-  // The check above guarantees that addr + begin_ will not overflow.
-  return memory_->Read(addr + begin_, dst, size);
+  return memory_->ReadPartially(addr, dst, size);
 }
 
 }  // namespace unwindstack
diff --git a/libunwindstack/include/unwindstack/Memory.h b/libunwindstack/include/unwindstack/Memory.h
index 183b899..d747fa7 100644
--- a/libunwindstack/include/unwindstack/Memory.h
+++ b/libunwindstack/include/unwindstack/Memory.h
@@ -36,7 +36,9 @@
 
   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;
+  virtual size_t ReadPartially(uint64_t addr, void* dst, size_t size) = 0;
+
+  bool Read(uint64_t addr, void* dst, size_t size);
 
   inline bool ReadField(uint64_t addr, void* start, void* field, size_t size) {
     if (reinterpret_cast<uintptr_t>(field) < reinterpret_cast<uintptr_t>(start)) {
@@ -60,7 +62,7 @@
   MemoryBuffer() = default;
   virtual ~MemoryBuffer() = default;
 
-  bool Read(uint64_t addr, void* dst, size_t size) override;
+  size_t ReadPartially(uint64_t addr, void* dst, size_t size) override;
 
   uint8_t* GetPtr(size_t offset);
 
@@ -79,7 +81,9 @@
 
   bool Init(const std::string& file, uint64_t offset, uint64_t size = UINT64_MAX);
 
-  bool Read(uint64_t addr, void* dst, size_t size) override;
+  size_t ReadPartially(uint64_t addr, void* dst, size_t size) override;
+
+  size_t Size() { return size_; }
 
   void Clear();
 
@@ -89,31 +93,15 @@
   uint8_t* data_ = nullptr;
 };
 
-class MemoryOffline : public MemoryFileAtOffset {
- public:
-  MemoryOffline() = default;
-  virtual ~MemoryOffline() = default;
-
-  bool Init(const std::string& file, uint64_t offset);
-
-  bool Read(uint64_t addr, void* dst, size_t size) override;
-
- private:
-  uint64_t start_;
-};
-
 class MemoryRemote : public Memory {
  public:
   MemoryRemote(pid_t pid) : pid_(pid) {}
   virtual ~MemoryRemote() = default;
 
-  bool Read(uint64_t addr, void* dst, size_t size) override;
+  size_t ReadPartially(uint64_t addr, void* dst, size_t size) override;
 
   pid_t pid() { return pid_; }
 
- protected:
-  virtual bool PtraceRead(uint64_t addr, long* value);
-
  private:
   pid_t pid_;
 };
@@ -123,20 +111,38 @@
   MemoryLocal() = default;
   virtual ~MemoryLocal() = default;
 
-  bool Read(uint64_t addr, void* dst, size_t size) override;
+  size_t ReadPartially(uint64_t addr, void* dst, size_t size) override;
 };
 
+// MemoryRange maps one address range onto another.
+// The range [src_begin, src_begin + length) in the underlying Memory is mapped onto offset,
+// such that range.read(offset) is equivalent to underlying.read(src_begin).
 class MemoryRange : public Memory {
  public:
-  MemoryRange(const std::shared_ptr<Memory>& memory, uint64_t begin, uint64_t end);
+  MemoryRange(const std::shared_ptr<Memory>& memory, uint64_t begin, uint64_t length,
+              uint64_t offset);
   virtual ~MemoryRange() = default;
 
-  bool Read(uint64_t addr, void* dst, size_t size) override;
+  size_t ReadPartially(uint64_t addr, void* dst, size_t size) override;
 
  private:
   std::shared_ptr<Memory> memory_;
   uint64_t begin_;
   uint64_t length_;
+  uint64_t offset_;
+};
+
+class MemoryOffline : public Memory {
+ public:
+  MemoryOffline() = default;
+  virtual ~MemoryOffline() = default;
+
+  bool Init(const std::string& file, uint64_t offset);
+
+  size_t ReadPartially(uint64_t addr, void* dst, size_t size) override;
+
+ private:
+  std::unique_ptr<MemoryRange> memory_;
 };
 
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MemoryBufferTest.cpp b/libunwindstack/tests/MemoryBufferTest.cpp
index 50a8a1b..be5a520 100644
--- a/libunwindstack/tests/MemoryBufferTest.cpp
+++ b/libunwindstack/tests/MemoryBufferTest.cpp
@@ -78,4 +78,24 @@
   ASSERT_FALSE(memory_->Read(UINT64_MAX - 100, buffer.data(), 200));
 }
 
+TEST_F(MemoryBufferTest, ReadPartially) {
+  memory_->Resize(256);
+  ASSERT_EQ(256U, memory_->Size());
+  ASSERT_TRUE(memory_->GetPtr(0) != nullptr);
+  ASSERT_TRUE(memory_->GetPtr(1) != nullptr);
+  ASSERT_TRUE(memory_->GetPtr(255) != nullptr);
+  ASSERT_TRUE(memory_->GetPtr(256) == nullptr);
+
+  uint8_t* data = memory_->GetPtr(0);
+  for (size_t i = 0; i < memory_->Size(); i++) {
+    data[i] = i;
+  }
+
+  std::vector<uint8_t> buffer(memory_->Size());
+  ASSERT_EQ(128U, memory_->ReadPartially(128, buffer.data(), buffer.size()));
+  for (size_t i = 0; i < 128; i++) {
+    ASSERT_EQ(128 + i, buffer[i]) << "Failed at byte " << i;
+  }
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MemoryFake.cpp b/libunwindstack/tests/MemoryFake.cpp
index 2026acc..e340dba 100644
--- a/libunwindstack/tests/MemoryFake.cpp
+++ b/libunwindstack/tests/MemoryFake.cpp
@@ -35,16 +35,16 @@
   }
 }
 
-bool MemoryFake::Read(uint64_t addr, void* memory, size_t size) {
+size_t MemoryFake::ReadPartially(uint64_t addr, void* memory, size_t size) {
   uint8_t* dst = reinterpret_cast<uint8_t*>(memory);
   for (size_t i = 0; i < size; i++, addr++) {
     auto value = data_.find(addr);
     if (value == data_.end()) {
-      return false;
+      return i;
     }
     dst[i] = value->second;
   }
-  return true;
+  return size;
 }
 
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MemoryFake.h b/libunwindstack/tests/MemoryFake.h
index d374261..2b0297c 100644
--- a/libunwindstack/tests/MemoryFake.h
+++ b/libunwindstack/tests/MemoryFake.h
@@ -32,7 +32,7 @@
   MemoryFake() = default;
   virtual ~MemoryFake() = default;
 
-  bool Read(uint64_t addr, void* buffer, size_t size) override;
+  size_t ReadPartially(uint64_t addr, void* buffer, size_t size) override;
 
   void SetMemory(uint64_t addr, const void* memory, size_t length);
 
@@ -71,21 +71,9 @@
   MemoryFakeAlwaysReadZero() = default;
   virtual ~MemoryFakeAlwaysReadZero() = default;
 
-  bool Read(uint64_t, void* buffer, size_t size) override {
+  size_t ReadPartially(uint64_t, void* buffer, size_t size) override {
     memset(buffer, 0, size);
-    return true;
-  }
-};
-
-class MemoryFakeRemote : public MemoryRemote {
- public:
-  MemoryFakeRemote() : MemoryRemote(0) {}
-  virtual ~MemoryFakeRemote() = default;
-
- protected:
-  bool PtraceRead(uint64_t, long* value) override {
-    *value = 0;
-    return true;
+    return size;
   }
 };
 
diff --git a/libunwindstack/tests/MemoryLocalTest.cpp b/libunwindstack/tests/MemoryLocalTest.cpp
index 73eebdd..957b239 100644
--- a/libunwindstack/tests/MemoryLocalTest.cpp
+++ b/libunwindstack/tests/MemoryLocalTest.cpp
@@ -16,6 +16,7 @@
 
 #include <stdint.h>
 #include <string.h>
+#include <sys/mman.h>
 
 #include <vector>
 
@@ -67,4 +68,44 @@
   ASSERT_FALSE(local.Read(reinterpret_cast<uint64_t>(&value), dst.data(), SIZE_MAX));
 }
 
+TEST(MemoryLocalTest, ReadPartially) {
+  char* mapping = static_cast<char*>(
+      mmap(nullptr, 2 * getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
+
+  ASSERT_NE(MAP_FAILED, mapping);
+
+  mprotect(mapping + getpagesize(), getpagesize(), PROT_NONE);
+  memset(mapping + getpagesize() - 1024, 0x4c, 1024);
+
+  MemoryLocal local;
+
+  std::vector<uint8_t> dst(4096);
+  ASSERT_EQ(1024U, local.ReadPartially(reinterpret_cast<uint64_t>(mapping + getpagesize() - 1024),
+                                       dst.data(), 4096));
+  for (size_t i = 0; i < 1024; i++) {
+    ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
+  }
+
+  ASSERT_EQ(0, munmap(mapping, 2 * getpagesize()));
+}
+
+TEST(MemoryLocalTest, read_hole) {
+  void* mapping =
+      mmap(nullptr, 3 * 4096, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+  ASSERT_NE(MAP_FAILED, mapping);
+  memset(mapping, 0xFF, 3 * 4096);
+  mprotect(static_cast<char*>(mapping) + 4096, 4096, PROT_NONE);
+
+  MemoryLocal local;
+  std::vector<uint8_t> dst(4096 * 3, 0xCC);
+  ASSERT_EQ(4096U, local.ReadPartially(reinterpret_cast<uintptr_t>(mapping), dst.data(), 4096 * 3));
+  for (size_t i = 0; i < 4096; ++i) {
+    ASSERT_EQ(0xFF, dst[i]);
+  }
+  for (size_t i = 4096; i < 4096 * 3; ++i) {
+    ASSERT_EQ(0xCC, dst[i]);
+  }
+  ASSERT_EQ(0, munmap(mapping, 3 * 4096));
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MemoryRangeTest.cpp b/libunwindstack/tests/MemoryRangeTest.cpp
index 680fae9..4a764f5 100644
--- a/libunwindstack/tests/MemoryRangeTest.cpp
+++ b/libunwindstack/tests/MemoryRangeTest.cpp
@@ -35,7 +35,7 @@
   std::shared_ptr<Memory> process_memory(memory_fake);
   memory_fake->SetMemory(9001, src);
 
-  MemoryRange range(process_memory, 9001, 9001 + src.size());
+  MemoryRange range(process_memory, 9001, src.size(), 0);
 
   std::vector<uint8_t> dst(1024);
   ASSERT_TRUE(range.Read(0, dst.data(), src.size()));
@@ -51,7 +51,7 @@
   std::shared_ptr<Memory> process_memory(memory_fake);
   memory_fake->SetMemory(1000, src);
 
-  MemoryRange range(process_memory, 1000, 2024);
+  MemoryRange range(process_memory, 1000, 1024, 0);
 
   std::vector<uint8_t> dst(1024);
   ASSERT_TRUE(range.Read(1020, dst.data(), 4));
@@ -72,8 +72,23 @@
   std::vector<uint8_t> buffer(100);
 
   std::shared_ptr<Memory> process_memory(new MemoryFakeAlwaysReadZero);
-  std::unique_ptr<MemoryRange> overflow(new MemoryRange(process_memory, 100, 200));
+  std::unique_ptr<MemoryRange> overflow(new MemoryRange(process_memory, 100, 200, 0));
   ASSERT_FALSE(overflow->Read(UINT64_MAX - 10, buffer.data(), 100));
 }
 
+TEST(MemoryRangeTest, ReadPartially) {
+  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);
+
+  MemoryRange range(process_memory, 1000, 1024, 0);
+  std::vector<uint8_t> dst(1024);
+  ASSERT_EQ(4U, range.ReadPartially(1020, dst.data(), 1024));
+  for (size_t i = 0; i < 4; i++) {
+    ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
+  }
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/tests/MemoryRemoteTest.cpp b/libunwindstack/tests/MemoryRemoteTest.cpp
index a66d0c5..8ab8068 100644
--- a/libunwindstack/tests/MemoryRemoteTest.cpp
+++ b/libunwindstack/tests/MemoryRemoteTest.cpp
@@ -79,6 +79,38 @@
   ASSERT_TRUE(Detach(pid));
 }
 
+TEST_F(MemoryRemoteTest, ReadPartially) {
+  char* mapping = static_cast<char*>(
+      mmap(nullptr, 2 * getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
+
+  ASSERT_NE(MAP_FAILED, mapping);
+
+  mprotect(mapping + getpagesize(), getpagesize(), PROT_NONE);
+  memset(mapping + getpagesize() - 1024, 0x4c, 1024);
+
+  pid_t pid;
+  if ((pid = fork()) == 0) {
+    while (true);
+    exit(1);
+  }
+  ASSERT_LT(0, pid);
+  TestScopedPidReaper reap(pid);
+
+  ASSERT_TRUE(Attach(pid));
+
+  MemoryRemote remote(pid);
+
+  std::vector<uint8_t> dst(4096);
+  ASSERT_EQ(1024U, remote.ReadPartially(reinterpret_cast<uint64_t>(mapping + getpagesize() - 1024),
+                                        dst.data(), 4096));
+  for (size_t i = 0; i < 1024; i++) {
+    ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
+  }
+
+  ASSERT_TRUE(Detach(pid));
+  ASSERT_EQ(0, munmap(mapping, 2 * getpagesize()));
+}
+
 TEST_F(MemoryRemoteTest, read_fail) {
   int pagesize = getpagesize();
   void* src = mmap(nullptr, pagesize * 2, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,-1, 0);
@@ -119,11 +151,23 @@
 }
 
 TEST_F(MemoryRemoteTest, read_overflow) {
-  MemoryFakeRemote remote;
+  pid_t pid;
+  if ((pid = fork()) == 0) {
+    while (true);
+    exit(1);
+  }
+  ASSERT_LT(0, pid);
+  TestScopedPidReaper reap(pid);
+
+  ASSERT_TRUE(Attach(pid));
+
+  MemoryRemote remote(pid);
 
   // Check overflow condition is caught properly.
   std::vector<uint8_t> dst(200);
   ASSERT_FALSE(remote.Read(UINT64_MAX - 100, dst.data(), 200));
+
+  ASSERT_TRUE(Detach(pid));
 }
 
 TEST_F(MemoryRemoteTest, read_illegal) {
@@ -146,4 +190,32 @@
   ASSERT_TRUE(Detach(pid));
 }
 
+TEST_F(MemoryRemoteTest, read_hole) {
+  void* mapping =
+      mmap(nullptr, 3 * 4096, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+  ASSERT_NE(MAP_FAILED, mapping);
+  memset(mapping, 0xFF, 3 * 4096);
+  mprotect(static_cast<char*>(mapping) + 4096, 4096, PROT_NONE);
+
+  pid_t pid;
+  if ((pid = fork()) == 0) {
+    while (true);
+    exit(1);
+  }
+  ASSERT_LT(0, pid);
+  TestScopedPidReaper reap(pid);
+
+  ASSERT_TRUE(Attach(pid));
+
+  MemoryRemote remote(pid);
+  std::vector<uint8_t> dst(4096 * 3, 0xCC);
+  ASSERT_EQ(4096U, remote.ReadPartially(reinterpret_cast<uintptr_t>(mapping), dst.data(), 4096 * 3));
+  for (size_t i = 0; i < 4096; ++i) {
+    ASSERT_EQ(0xFF, dst[i]);
+  }
+  for (size_t i = 4096; i < 4096 * 3; ++i) {
+    ASSERT_EQ(0xCC, dst[i]);
+  }
+}
+
 }  // namespace unwindstack