diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 7411e5a..8e3875f 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -72,6 +72,8 @@
 
 static constexpr const std::string_view kCowGroupName = "cow";
 
+bool SourceCopyOperationIsClone(const chromeos_update_engine::InstallOperation& operation);
+
 enum class UpdateState : unsigned int {
     // No update or merge is in progress.
     None,
diff --git a/fs_mgr/libsnapshot/partition_cow_creator.cpp b/fs_mgr/libsnapshot/partition_cow_creator.cpp
index 77315b4..61f5c0c 100644
--- a/fs_mgr/libsnapshot/partition_cow_creator.cpp
+++ b/fs_mgr/libsnapshot/partition_cow_creator.cpp
@@ -62,27 +62,52 @@
     return false;
 }
 
+bool SourceCopyOperationIsClone(const InstallOperation& operation) {
+    using ChromeOSExtent = chromeos_update_engine::Extent;
+    if (operation.src_extents().size() != operation.dst_extents().size()) {
+        return false;
+    }
+    return std::equal(operation.src_extents().begin(), operation.src_extents().end(),
+                      operation.dst_extents().begin(),
+                      [](const ChromeOSExtent& src, const ChromeOSExtent& dst) {
+                          return src.start_block() == dst.start_block() &&
+                                 src.num_blocks() == dst.num_blocks();
+                      });
+}
+
+void WriteExtent(DmSnapCowSizeCalculator* sc, const chromeos_update_engine::Extent& de,
+                 unsigned int sectors_per_block) {
+    const auto block_boundary = de.start_block() + de.num_blocks();
+    for (auto b = de.start_block(); b < block_boundary; ++b) {
+        for (unsigned int s = 0; s < sectors_per_block; ++s) {
+            const auto sector_id = b * sectors_per_block + s;
+            sc->WriteSector(sector_id);
+        }
+    }
+}
+
 uint64_t PartitionCowCreator::GetCowSize() {
     // WARNING: The origin partition should be READ-ONLY
     const uint64_t logical_block_size = current_metadata->logical_block_size();
     const unsigned int sectors_per_block = logical_block_size / kSectorSize;
     DmSnapCowSizeCalculator sc(kSectorSize, kSnapshotChunkSize);
 
+    // Allocate space for extra extents (if any). These extents are those that can be
+    // used for error corrections or to store verity hash trees.
+    for (const auto& de : extra_extents) {
+        WriteExtent(&sc, de, sectors_per_block);
+    }
+
     if (operations == nullptr) return sc.cow_size_bytes();
 
     for (const auto& iop : *operations) {
-        for (const auto& de : iop.dst_extents()) {
-            // Skip if no blocks are written
-            if (de.num_blocks() == 0) continue;
+        // Do not allocate space for operations that are going to be skipped
+        // during OTA application.
+        if (iop.type() == InstallOperation::SOURCE_COPY && SourceCopyOperationIsClone(iop))
+            continue;
 
-            // Flag all the blocks that were written
-            const auto block_boundary = de.start_block() + de.num_blocks();
-            for (auto b = de.start_block(); b < block_boundary; ++b) {
-                for (unsigned int s = 0; s < sectors_per_block; ++s) {
-                    const auto sector_id = b * sectors_per_block + s;
-                    sc.WriteSector(sector_id);
-                }
-            }
+        for (const auto& de : iop.dst_extents()) {
+            WriteExtent(&sc, de, sectors_per_block);
         }
     }
 
diff --git a/fs_mgr/libsnapshot/partition_cow_creator.h b/fs_mgr/libsnapshot/partition_cow_creator.h
index d3d186b..699f9a1 100644
--- a/fs_mgr/libsnapshot/partition_cow_creator.h
+++ b/fs_mgr/libsnapshot/partition_cow_creator.h
@@ -18,6 +18,7 @@
 
 #include <optional>
 #include <string>
+#include <vector>
 
 #include <liblp/builder.h>
 #include <update_engine/update_metadata.pb.h>
@@ -30,6 +31,7 @@
 // Helper class that creates COW for a partition.
 struct PartitionCowCreator {
     using Extent = android::fs_mgr::Extent;
+    using ChromeOSExtent = chromeos_update_engine::Extent;
     using Interval = android::fs_mgr::Interval;
     using MetadataBuilder = android::fs_mgr::MetadataBuilder;
     using Partition = android::fs_mgr::Partition;
@@ -50,6 +52,9 @@
     std::string current_suffix;
     // List of operations to be applied on the partition.
     const RepeatedPtrField<InstallOperation>* operations = nullptr;
+    // Extra extents that are going to be invalidated during the update
+    // process.
+    std::vector<ChromeOSExtent> extra_extents = {};
 
     struct Return {
         SnapshotStatus snapshot_status;
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 0fb4af9..80d73c3 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -65,6 +65,7 @@
 using android::fs_mgr::SlotNumberForSlotSuffix;
 using android::hardware::boot::V1_1::MergeStatus;
 using chromeos_update_engine::DeltaArchiveManifest;
+using chromeos_update_engine::Extent;
 using chromeos_update_engine::InstallOperation;
 template <typename T>
 using RepeatedPtrField = google::protobuf::RepeatedPtrField<T>;
@@ -128,6 +129,13 @@
     auto file = LockExclusive();
     if (!file) return false;
 
+    // Purge the ImageManager just in case there is a corrupt lp_metadata file
+    // lying around. (NB: no need to return false on an error, we can let the
+    // update try to progress.)
+    if (EnsureImageManager()) {
+        images_->RemoveAllImages();
+    }
+
     auto state = ReadUpdateState(file.get());
     if (state != UpdateState::None) {
         LOG(ERROR) << "An update is already in progress, cannot begin a new update";
@@ -1181,8 +1189,26 @@
     }
 
     bool ok = true;
+    bool has_mapped_cow_images = false;
     for (const auto& name : snapshots) {
-        ok &= (UnmapPartitionWithSnapshot(lock, name) && DeleteSnapshot(lock, name));
+        if (!UnmapPartitionWithSnapshot(lock, name) || !DeleteSnapshot(lock, name)) {
+            // Remember whether or not we were able to unmap the cow image.
+            auto cow_image_device = GetCowImageDeviceName(name);
+            has_mapped_cow_images |= images_->IsImageMapped(cow_image_device);
+
+            ok = false;
+        }
+    }
+
+    if (ok || !has_mapped_cow_images) {
+        // Delete any image artifacts as a precaution, in case an update is
+        // being cancelled due to some corrupted state in an lp_metadata file.
+        // Note that we do not do this if some cow images are still mapped,
+        // since we must not remove backing storage if it's in use.
+        if (!EnsureImageManager() || !images_->RemoveAllImages()) {
+            LOG(ERROR) << "Could not remove all snapshot artifacts";
+            return false;
+        }
     }
     return ok;
 }
@@ -1886,12 +1912,15 @@
     // these devices.
     AutoDeviceList created_devices;
 
-    PartitionCowCreator cow_creator{.target_metadata = target_metadata.get(),
-                                    .target_suffix = target_suffix,
-                                    .target_partition = nullptr,
-                                    .current_metadata = current_metadata.get(),
-                                    .current_suffix = current_suffix,
-                                    .operations = nullptr};
+    PartitionCowCreator cow_creator{
+            .target_metadata = target_metadata.get(),
+            .target_suffix = target_suffix,
+            .target_partition = nullptr,
+            .current_metadata = current_metadata.get(),
+            .current_suffix = current_suffix,
+            .operations = nullptr,
+            .extra_extents = {},
+    };
 
     if (!CreateUpdateSnapshotsInternal(lock.get(), manifest, &cow_creator, &created_devices,
                                        &all_snapshot_status)) {
@@ -1937,15 +1966,24 @@
     }
 
     std::map<std::string, const RepeatedPtrField<InstallOperation>*> install_operation_map;
+    std::map<std::string, std::vector<Extent>> extra_extents_map;
     for (const auto& partition_update : manifest.partitions()) {
         auto suffixed_name = partition_update.partition_name() + target_suffix;
-        auto&& [it, inserted] = install_operation_map.emplace(std::move(suffixed_name),
-                                                              &partition_update.operations());
+        auto&& [it, inserted] =
+                install_operation_map.emplace(suffixed_name, &partition_update.operations());
         if (!inserted) {
             LOG(ERROR) << "Duplicated partition " << partition_update.partition_name()
                        << " in update manifest.";
             return false;
         }
+
+        auto& extra_extents = extra_extents_map[suffixed_name];
+        if (partition_update.has_hash_tree_extent()) {
+            extra_extents.push_back(partition_update.hash_tree_extent());
+        }
+        if (partition_update.has_fec_extent()) {
+            extra_extents.push_back(partition_update.fec_extent());
+        }
     }
 
     for (auto* target_partition : ListPartitionsWithSuffix(target_metadata, target_suffix)) {
@@ -1956,6 +1994,12 @@
             cow_creator->operations = operations_it->second;
         }
 
+        cow_creator->extra_extents.clear();
+        auto extra_extents_it = extra_extents_map.find(target_partition->name());
+        if (extra_extents_it != extra_extents_map.end()) {
+            cow_creator->extra_extents = std::move(extra_extents_it->second);
+        }
+
         // Compute the device sizes for the partition.
         auto cow_creator_ret = cow_creator->Run();
         if (!cow_creator_ret.has_value()) {
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index 7d6e78f..1d2a1f1 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -716,6 +716,45 @@
         return AssertionSuccess();
     }
 
+    AssertionResult MapUpdateSnapshot(const std::string& name, std::string* path = nullptr) {
+        std::string real_path;
+        if (!sm->MapUpdateSnapshot(
+                    CreateLogicalPartitionParams{
+                            .block_device = fake_super,
+                            .metadata_slot = 1,
+                            .partition_name = name,
+                            .timeout_ms = 10s,
+                            .partition_opener = opener_.get(),
+                    },
+                    &real_path)) {
+            return AssertionFailure() << "Unable to map snapshot " << name;
+        }
+        if (path) {
+            *path = real_path;
+        }
+        return AssertionSuccess() << "Mapped snapshot " << name << " to " << real_path;
+    }
+
+    AssertionResult WriteSnapshotAndHash(const std::string& name,
+                                         std::optional<size_t> size = std::nullopt) {
+        std::string path;
+        auto res = MapUpdateSnapshot(name, &path);
+        if (!res) {
+            return res;
+        }
+
+        std::string size_string = size ? (std::to_string(*size) + " bytes") : "";
+
+        if (!WriteRandomData(path, size, &hashes_[name])) {
+            return AssertionFailure() << "Unable to write " << size_string << " to " << path
+                                      << " for partition " << name;
+        }
+
+        return AssertionSuccess() << "Written " << size_string << " to " << path
+                                  << " for snapshot partition " << name
+                                  << ", hash: " << hashes_[name];
+    }
+
     std::unique_ptr<TestPartitionOpener> opener_;
     DeltaArchiveManifest manifest_;
     std::unique_ptr<MetadataBuilder> src_;
@@ -762,21 +801,7 @@
 
     // Write some data to target partitions.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
-        std::string path;
-        ASSERT_TRUE(sm->MapUpdateSnapshot(
-                CreateLogicalPartitionParams{
-                        .block_device = fake_super,
-                        .metadata_slot = 1,
-                        .partition_name = name,
-                        .timeout_ms = 10s,
-                        .partition_opener = opener_.get(),
-                },
-                &path))
-                << name;
-        ASSERT_TRUE(WriteRandomData(path));
-        auto hash = GetHash(path);
-        ASSERT_TRUE(hash.has_value());
-        hashes_[name] = *hash;
+        ASSERT_TRUE(WriteSnapshotAndHash(name, partition_size));
     }
 
     // Assert that source partitions aren't affected.
@@ -890,17 +915,7 @@
 
     // Check that target partitions can be mapped.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
-        std::string path;
-        EXPECT_TRUE(sm->MapUpdateSnapshot(
-                CreateLogicalPartitionParams{
-                        .block_device = fake_super,
-                        .metadata_slot = 1,
-                        .partition_name = name,
-                        .timeout_ms = 10s,
-                        .partition_opener = opener_.get(),
-                },
-                &path))
-                << name;
+        EXPECT_TRUE(MapUpdateSnapshot(name));
     }
 }
 
@@ -921,21 +936,7 @@
 
     // Write some data to target partitions.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
-        std::string path;
-        ASSERT_TRUE(sm->MapUpdateSnapshot(
-                CreateLogicalPartitionParams{
-                        .block_device = fake_super,
-                        .metadata_slot = 1,
-                        .partition_name = name,
-                        .timeout_ms = 10s,
-                        .partition_opener = opener_.get(),
-                },
-                &path))
-                << name;
-        ASSERT_TRUE(WriteRandomData(path));
-        auto hash = GetHash(path);
-        ASSERT_TRUE(hash.has_value());
-        hashes_[name] = *hash;
+        ASSERT_TRUE(WriteSnapshotAndHash(name));
     }
 
     // Assert that source partitions aren't affected.
@@ -1089,21 +1090,7 @@
 
     // Write some data to target partitions.
     for (const auto& name : {"sys_b", "vnd_b", "prd_b"}) {
-        std::string path;
-        ASSERT_TRUE(sm->MapUpdateSnapshot(
-                CreateLogicalPartitionParams{
-                        .block_device = fake_super,
-                        .metadata_slot = 1,
-                        .partition_name = name,
-                        .timeout_ms = 10s,
-                        .partition_opener = opener_.get(),
-                },
-                &path))
-                << name;
-        ASSERT_TRUE(WriteRandomData(path));
-        auto hash = GetHash(path);
-        ASSERT_TRUE(hash.has_value());
-        hashes_[name] = *hash;
+        ASSERT_TRUE(WriteSnapshotAndHash(name));
     }
 
     // Assert that source partitions aren't affected.
@@ -1313,6 +1300,56 @@
     EXPECT_FALSE(test_device->IsSlotUnbootable(0));
 }
 
+TEST_F(SnapshotUpdateTest, Hashtree) {
+    constexpr auto partition_size = 4_MiB;
+    constexpr auto data_size = 3_MiB;
+    constexpr auto hashtree_size = 512_KiB;
+    constexpr auto fec_size = partition_size - data_size - hashtree_size;
+
+    const auto block_size = manifest_.block_size();
+    SetSize(sys_, partition_size);
+
+    auto e = sys_->add_operations()->add_dst_extents();
+    e->set_start_block(0);
+    e->set_num_blocks(data_size / block_size);
+
+    // Set hastree extents.
+    sys_->mutable_hash_tree_data_extent()->set_start_block(0);
+    sys_->mutable_hash_tree_data_extent()->set_num_blocks(data_size / block_size);
+
+    sys_->mutable_hash_tree_extent()->set_start_block(data_size / block_size);
+    sys_->mutable_hash_tree_extent()->set_num_blocks(hashtree_size / block_size);
+
+    // Set FEC extents.
+    sys_->mutable_fec_data_extent()->set_start_block(0);
+    sys_->mutable_fec_data_extent()->set_num_blocks((data_size + hashtree_size) / block_size);
+
+    sys_->mutable_fec_extent()->set_start_block((data_size + hashtree_size) / block_size);
+    sys_->mutable_fec_extent()->set_num_blocks(fec_size / block_size);
+
+    ASSERT_TRUE(sm->BeginUpdate());
+    ASSERT_TRUE(sm->CreateUpdateSnapshots(manifest_));
+
+    // Write some data to target partition.
+    ASSERT_TRUE(WriteSnapshotAndHash("sys_b", partition_size));
+
+    // Finish update.
+    ASSERT_TRUE(sm->FinishedSnapshotWrites());
+
+    // Simulate shutting down the device.
+    ASSERT_TRUE(UnmapAll());
+
+    // After reboot, init does first stage mount.
+    auto init = SnapshotManager::NewForFirstStageMount(new TestDeviceInfo(fake_super, "_b"));
+    ASSERT_NE(init, nullptr);
+    ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
+    ASSERT_TRUE(init->CreateLogicalAndSnapshotPartitions("super"));
+
+    // Check that the target partition have the same content. Hashtree and FEC extents
+    // should be accounted for.
+    ASSERT_TRUE(IsPartitionUnchanged("sys_b"));
+}
+
 class FlashAfterUpdateTest : public SnapshotUpdateTest,
                              public WithParamInterface<std::tuple<uint32_t, bool>> {
   public:
diff --git a/fs_mgr/libsnapshot/snapshotctl.rc b/fs_mgr/libsnapshot/snapshotctl.rc
index 29707f1..3ab0645 100644
--- a/fs_mgr/libsnapshot/snapshotctl.rc
+++ b/fs_mgr/libsnapshot/snapshotctl.rc
@@ -1,2 +1,2 @@
 on property:sys.boot_completed=1
-    exec - root root -- /system/bin/snapshotctl merge --logcat
+    exec_background - root root -- /system/bin/snapshotctl merge --logcat
diff --git a/fs_mgr/libsnapshot/test_helpers.cpp b/fs_mgr/libsnapshot/test_helpers.cpp
index 312fa3e..2d62347 100644
--- a/fs_mgr/libsnapshot/test_helpers.cpp
+++ b/fs_mgr/libsnapshot/test_helpers.cpp
@@ -62,24 +62,6 @@
     return PartitionOpener::GetDeviceString(partition_name);
 }
 
-bool WriteRandomData(const std::string& path) {
-    unique_fd rand(open("/dev/urandom", O_RDONLY));
-    unique_fd fd(open(path.c_str(), O_WRONLY));
-
-    char buf[4096];
-    while (true) {
-        ssize_t n = TEMP_FAILURE_RETRY(read(rand.get(), buf, sizeof(buf)));
-        if (n <= 0) return false;
-        if (!WriteFully(fd.get(), buf, n)) {
-            if (errno == ENOSPC) {
-                return true;
-            }
-            PLOG(ERROR) << "Cannot write " << path;
-            return false;
-        }
-    }
-}
-
 std::string ToHexString(const uint8_t* buf, size_t len) {
     char lookup[] = "0123456789abcdef";
     std::string out(len * 2 + 1, '\0');
@@ -91,6 +73,47 @@
     return out;
 }
 
+bool WriteRandomData(const std::string& path, std::optional<size_t> expect_size,
+                     std::string* hash) {
+    unique_fd rand(open("/dev/urandom", O_RDONLY));
+    unique_fd fd(open(path.c_str(), O_WRONLY));
+
+    SHA256_CTX ctx;
+    if (hash) {
+        SHA256_Init(&ctx);
+    }
+
+    char buf[4096];
+    size_t total_written = 0;
+    while (!expect_size || total_written < *expect_size) {
+        ssize_t n = TEMP_FAILURE_RETRY(read(rand.get(), buf, sizeof(buf)));
+        if (n <= 0) return false;
+        if (!WriteFully(fd.get(), buf, n)) {
+            if (errno == ENOSPC) {
+                break;
+            }
+            PLOG(ERROR) << "Cannot write " << path;
+            return false;
+        }
+        total_written += n;
+        if (hash) {
+            SHA256_Update(&ctx, buf, n);
+        }
+    }
+
+    if (expect_size && total_written != *expect_size) {
+        PLOG(ERROR) << "Written " << total_written << " bytes, expected " << *expect_size;
+        return false;
+    }
+
+    if (hash) {
+        uint8_t out[32];
+        SHA256_Final(out, &ctx);
+        *hash = ToHexString(out, sizeof(out));
+    }
+    return true;
+}
+
 std::optional<std::string> GetHash(const std::string& path) {
     std::string content;
     if (!android::base::ReadFileToString(path, &content, true)) {
diff --git a/fs_mgr/libsnapshot/test_helpers.h b/fs_mgr/libsnapshot/test_helpers.h
index 9083843..2bf1b57 100644
--- a/fs_mgr/libsnapshot/test_helpers.h
+++ b/fs_mgr/libsnapshot/test_helpers.h
@@ -137,8 +137,11 @@
 // Helper for error-spam-free cleanup.
 void DeleteBackingImage(android::fiemap::IImageManager* manager, const std::string& name);
 
-// Write some random data to the given device. Will write until reaching end of the device.
-bool WriteRandomData(const std::string& device);
+// Write some random data to the given device.
+// If expect_size is not specified, will write until reaching end of the device.
+// Expect space of |path| is multiple of 4K.
+bool WriteRandomData(const std::string& path, std::optional<size_t> expect_size = std::nullopt,
+                     std::string* hash = nullptr);
 
 std::optional<std::string> GetHash(const std::string& path);
 
diff --git a/libunwindstack/Elf.cpp b/libunwindstack/Elf.cpp
index c141b2e..6627787 100644
--- a/libunwindstack/Elf.cpp
+++ b/libunwindstack/Elf.cpp
@@ -112,35 +112,33 @@
                      gnu_debugdata_interface_->GetFunctionName(addr, name, func_offset)));
 }
 
-bool Elf::GetGlobalVariable(const std::string& name, uint64_t* memory_address) {
+bool Elf::GetGlobalVariableOffset(const std::string& name, uint64_t* memory_offset) {
   if (!valid_) {
     return false;
   }
 
-  if (!interface_->GetGlobalVariable(name, memory_address) &&
+  uint64_t vaddr;
+  if (!interface_->GetGlobalVariable(name, &vaddr) &&
       (gnu_debugdata_interface_ == nullptr ||
-       !gnu_debugdata_interface_->GetGlobalVariable(name, memory_address))) {
+       !gnu_debugdata_interface_->GetGlobalVariable(name, &vaddr))) {
     return false;
   }
 
-  // Adjust by the load bias.
-  if (load_bias_ > 0 && *memory_address < static_cast<uint64_t>(load_bias_)) {
-    return false;
+  // Check the .data section.
+  uint64_t vaddr_start = interface_->data_vaddr_start();
+  if (vaddr >= vaddr_start && vaddr < interface_->data_vaddr_end()) {
+    *memory_offset = vaddr - vaddr_start + interface_->data_offset();
+    return true;
   }
 
-  *memory_address -= load_bias_;
-
-  // If this winds up in the dynamic section, then we might need to adjust
-  // the address.
-  uint64_t dynamic_end = interface_->dynamic_vaddr() + interface_->dynamic_size();
-  if (*memory_address >= interface_->dynamic_vaddr() && *memory_address < dynamic_end) {
-    if (interface_->dynamic_vaddr() > interface_->dynamic_offset()) {
-      *memory_address -= interface_->dynamic_vaddr() - interface_->dynamic_offset();
-    } else {
-      *memory_address += interface_->dynamic_offset() - interface_->dynamic_vaddr();
-    }
+  // Check the .dynamic section.
+  vaddr_start = interface_->dynamic_vaddr_start();
+  if (vaddr >= vaddr_start && vaddr < interface_->dynamic_vaddr_end()) {
+    *memory_offset = vaddr - vaddr_start + interface_->dynamic_offset();
+    return true;
   }
-  return true;
+
+  return false;
 }
 
 std::string Elf::GetBuildID() {
diff --git a/libunwindstack/ElfInterface.cpp b/libunwindstack/ElfInterface.cpp
index 5f95fa8..7676289 100644
--- a/libunwindstack/ElfInterface.cpp
+++ b/libunwindstack/ElfInterface.cpp
@@ -236,8 +236,12 @@
 
     case PT_DYNAMIC:
       dynamic_offset_ = phdr.p_offset;
-      dynamic_vaddr_ = phdr.p_vaddr;
-      dynamic_size_ = phdr.p_memsz;
+      dynamic_vaddr_start_ = phdr.p_vaddr;
+      if (__builtin_add_overflow(dynamic_vaddr_start_, phdr.p_memsz, &dynamic_vaddr_end_)) {
+        dynamic_offset_ = 0;
+        dynamic_vaddr_start_ = 0;
+        dynamic_vaddr_end_ = 0;
+      }
       break;
 
     default:
@@ -360,6 +364,14 @@
             eh_frame_hdr_offset_ = shdr.sh_offset;
             eh_frame_hdr_section_bias_ = static_cast<uint64_t>(shdr.sh_addr) - shdr.sh_offset;
             eh_frame_hdr_size_ = shdr.sh_size;
+          } else if (name == ".data") {
+            data_offset_ = shdr.sh_offset;
+            data_vaddr_start_ = shdr.sh_addr;
+            if (__builtin_add_overflow(data_vaddr_start_, shdr.sh_size, &data_vaddr_end_)) {
+              data_offset_ = 0;
+              data_vaddr_start_ = 0;
+              data_vaddr_end_ = 0;
+            }
           }
         }
       }
@@ -398,7 +410,7 @@
   // Find the soname location from the dynamic headers section.
   DynType dyn;
   uint64_t offset = dynamic_offset_;
-  uint64_t max_offset = offset + dynamic_size_;
+  uint64_t max_offset = offset + dynamic_vaddr_end_ - dynamic_vaddr_start_;
   for (uint64_t offset = dynamic_offset_; offset < max_offset; offset += sizeof(DynType)) {
     if (!memory_->ReadFully(offset, &dyn, sizeof(dyn))) {
       last_error_.code = ERROR_MEMORY_INVALID;
diff --git a/libunwindstack/Global.cpp b/libunwindstack/Global.cpp
index a20be00..ec977e1 100644
--- a/libunwindstack/Global.cpp
+++ b/libunwindstack/Global.cpp
@@ -39,28 +39,22 @@
   }
 }
 
-uint64_t Global::GetVariableOffset(MapInfo* info, const std::string& variable) {
-  if (!search_libs_.empty()) {
-    bool found = false;
-    const char* lib = basename(info->name.c_str());
-    for (const std::string& name : search_libs_) {
-      if (name == lib) {
-        found = true;
-        break;
-      }
-    }
-    if (!found) {
-      return 0;
-    }
+bool Global::Searchable(const std::string& name) {
+  if (search_libs_.empty()) {
+    return true;
   }
 
-  Elf* elf = info->GetElf(memory_, arch());
-  uint64_t ptr;
-  // Find first non-empty list (libraries might be loaded multiple times).
-  if (elf->GetGlobalVariable(variable, &ptr) && ptr != 0) {
-    return ptr + info->start;
+  if (name.empty()) {
+    return false;
   }
-  return 0;
+
+  const char* base_name = basename(name.c_str());
+  for (const std::string& lib : search_libs_) {
+    if (base_name == lib) {
+      return true;
+    }
+  }
+  return false;
 }
 
 void Global::FindAndReadVariable(Maps* maps, const char* var_str) {
@@ -78,24 +72,27 @@
   //   f2000-f3000 2000 rw- /system/lib/libc.so
   MapInfo* map_start = nullptr;
   for (const auto& info : *maps) {
-    if (map_start != nullptr) {
-      if (map_start->name == info->name) {
-        if (info->offset != 0 &&
-            (info->flags & (PROT_READ | PROT_WRITE)) == (PROT_READ | PROT_WRITE)) {
-          uint64_t ptr = GetVariableOffset(map_start, variable);
-          if (ptr != 0 && ReadVariableData(ptr)) {
-            break;
-          } else {
-            // Failed to find the global variable, do not bother trying again.
-            map_start = nullptr;
+    if (map_start != nullptr && map_start->name == info->name) {
+      if (info->offset != 0 &&
+          (info->flags & (PROT_READ | PROT_WRITE)) == (PROT_READ | PROT_WRITE)) {
+        Elf* elf = map_start->GetElf(memory_, arch());
+        uint64_t ptr;
+        if (elf->GetGlobalVariableOffset(variable, &ptr) && ptr != 0) {
+          uint64_t offset_end = info->offset + info->end - info->start;
+          if (ptr >= info->offset && ptr < offset_end) {
+            ptr = info->start + ptr - info->offset;
+            if (ReadVariableData(ptr)) {
+              break;
+            }
           }
         }
-      } else {
         map_start = nullptr;
       }
+    } else {
+      map_start = nullptr;
     }
     if (map_start == nullptr && (info->flags & PROT_READ) && info->offset == 0 &&
-        !info->name.empty()) {
+        Searchable(info->name)) {
       map_start = info.get();
     }
   }
diff --git a/libunwindstack/include/unwindstack/Elf.h b/libunwindstack/include/unwindstack/Elf.h
index fc3f2a6..472ed92 100644
--- a/libunwindstack/include/unwindstack/Elf.h
+++ b/libunwindstack/include/unwindstack/Elf.h
@@ -63,7 +63,7 @@
 
   bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset);
 
-  bool GetGlobalVariable(const std::string& name, uint64_t* memory_address);
+  bool GetGlobalVariableOffset(const std::string& name, uint64_t* memory_offset);
 
   uint64_t GetRelPc(uint64_t pc, const MapInfo* map_info);
 
diff --git a/libunwindstack/include/unwindstack/ElfInterface.h b/libunwindstack/include/unwindstack/ElfInterface.h
index ae9bd9a..0c39b23 100644
--- a/libunwindstack/include/unwindstack/ElfInterface.h
+++ b/libunwindstack/include/unwindstack/ElfInterface.h
@@ -77,8 +77,11 @@
   void SetGnuDebugdataInterface(ElfInterface* interface) { gnu_debugdata_interface_ = interface; }
 
   uint64_t dynamic_offset() { return dynamic_offset_; }
-  uint64_t dynamic_vaddr() { return dynamic_vaddr_; }
-  uint64_t dynamic_size() { return dynamic_size_; }
+  uint64_t dynamic_vaddr_start() { return dynamic_vaddr_start_; }
+  uint64_t dynamic_vaddr_end() { return dynamic_vaddr_end_; }
+  uint64_t data_offset() { return data_offset_; }
+  uint64_t data_vaddr_start() { return data_vaddr_start_; }
+  uint64_t data_vaddr_end() { return data_vaddr_end_; }
   uint64_t eh_frame_hdr_offset() { return eh_frame_hdr_offset_; }
   int64_t eh_frame_hdr_section_bias() { return eh_frame_hdr_section_bias_; }
   uint64_t eh_frame_hdr_size() { return eh_frame_hdr_size_; }
@@ -141,8 +144,12 @@
 
   // Stored elf data.
   uint64_t dynamic_offset_ = 0;
-  uint64_t dynamic_vaddr_ = 0;
-  uint64_t dynamic_size_ = 0;
+  uint64_t dynamic_vaddr_start_ = 0;
+  uint64_t dynamic_vaddr_end_ = 0;
+
+  uint64_t data_offset_ = 0;
+  uint64_t data_vaddr_start_ = 0;
+  uint64_t data_vaddr_end_ = 0;
 
   uint64_t eh_frame_hdr_offset_ = 0;
   int64_t eh_frame_hdr_section_bias_ = 0;
diff --git a/libunwindstack/include/unwindstack/Global.h b/libunwindstack/include/unwindstack/Global.h
index a7e6c15..b9bb141 100644
--- a/libunwindstack/include/unwindstack/Global.h
+++ b/libunwindstack/include/unwindstack/Global.h
@@ -45,7 +45,7 @@
   ArchEnum arch() { return arch_; }
 
  protected:
-  uint64_t GetVariableOffset(MapInfo* info, const std::string& variable);
+  bool Searchable(const std::string& name);
   void FindAndReadVariable(Maps* maps, const char* variable);
 
   virtual bool ReadVariableData(uint64_t offset) = 0;
diff --git a/libunwindstack/tests/DexFilesTest.cpp b/libunwindstack/tests/DexFilesTest.cpp
index 1ea9e5c..0dd3af6 100644
--- a/libunwindstack/tests/DexFilesTest.cpp
+++ b/libunwindstack/tests/DexFilesTest.cpp
@@ -36,14 +36,18 @@
 
 class DexFilesTest : public ::testing::Test {
  protected:
-  void CreateFakeElf(MapInfo* map_info) {
+  void CreateFakeElf(MapInfo* map_info, uint64_t global_offset, uint64_t data_offset,
+                     uint64_t data_vaddr, uint64_t data_size) {
     MemoryFake* memory = new MemoryFake;
     ElfFake* elf = new ElfFake(memory);
     elf->FakeSetValid(true);
     ElfInterfaceFake* interface = new ElfInterfaceFake(memory);
     elf->FakeSetInterface(interface);
 
-    interface->FakeSetGlobalVariable("__dex_debug_descriptor", 0x800);
+    interface->FakeSetGlobalVariable("__dex_debug_descriptor", global_offset);
+    interface->FakeSetDataOffset(data_offset);
+    interface->FakeSetDataVaddrStart(data_vaddr);
+    interface->FakeSetDataVaddrEnd(data_vaddr + data_size);
     map_info->elf.reset(elf);
   }
 
@@ -54,11 +58,11 @@
     maps_.reset(
         new BufferMaps("1000-4000 ---s 00000000 00:00 0 /fake/elf\n"
                        "4000-6000 r--s 00000000 00:00 0 /fake/elf\n"
-                       "6000-8000 -wxs 00000000 00:00 0 /fake/elf\n"
+                       "6000-8000 -wxs 00002000 00:00 0 /fake/elf\n"
                        "a000-c000 r--p 00000000 00:00 0 /fake/elf2\n"
-                       "c000-f000 rw-p 00001000 00:00 0 /fake/elf2\n"
+                       "c000-f000 rw-p 00002000 00:00 0 /fake/elf2\n"
                        "f000-11000 r--p 00000000 00:00 0 /fake/elf3\n"
-                       "100000-110000 rw-p 0001000 00:00 0 /fake/elf3\n"
+                       "100000-110000 rw-p 00f1000 00:00 0 /fake/elf3\n"
                        "200000-210000 rw-p 0002000 00:00 0 /fake/elf3\n"
                        "300000-400000 rw-p 0003000 00:00 0 /fake/elf3\n"));
     ASSERT_TRUE(maps_->Parse());
@@ -66,17 +70,17 @@
     // Global variable in a section that is not readable.
     MapInfo* map_info = maps_->Get(kMapGlobalNonReadable);
     ASSERT_TRUE(map_info != nullptr);
-    CreateFakeElf(map_info);
+    CreateFakeElf(map_info, 0x2800, 0x2000, 0x2000, 0x3000);
 
     // Global variable not set by default.
     map_info = maps_->Get(kMapGlobalSetToZero);
     ASSERT_TRUE(map_info != nullptr);
-    CreateFakeElf(map_info);
+    CreateFakeElf(map_info, 0x2800, 0x2000, 0x2000, 0x3000);
 
     // Global variable set in this map.
     map_info = maps_->Get(kMapGlobal);
     ASSERT_TRUE(map_info != nullptr);
-    CreateFakeElf(map_info);
+    CreateFakeElf(map_info, 0xf1800, 0xf1000, 0xf1000, 0x10000);
   }
 
   void SetUp() override {
@@ -156,7 +160,7 @@
   uint64_t method_offset = 0x124;
   MapInfo* info = maps_->Get(kMapDexFiles);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x100800, 0x200000);
   WriteEntry32(0x200000, 0, 0, 0x300000);
   WriteDex(0x300000);
 
@@ -172,7 +176,7 @@
   uint64_t method_offset = 0x124;
   MapInfo* info = maps_->Get(kMapDexFiles);
 
-  WriteDescriptor64(0xf800, 0x200000);
+  WriteDescriptor64(0x100800, 0x200000);
   WriteEntry64(0x200000, 0, 0, 0x301000);
   WriteDex(0x301000);
 
@@ -186,7 +190,7 @@
   uint64_t method_offset = 0x124;
   MapInfo* info = maps_->Get(kMapDexFiles);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x100800, 0x200000);
   WriteEntry32(0x200000, 0x200100, 0, 0x100000);
   WriteEntry32(0x200100, 0, 0x200000, 0x300000);
   WriteDex(0x300000);
@@ -203,7 +207,7 @@
   uint64_t method_offset = 0x124;
   MapInfo* info = maps_->Get(kMapDexFiles);
 
-  WriteDescriptor64(0xf800, 0x200000);
+  WriteDescriptor64(0x100800, 0x200000);
   WriteEntry64(0x200000, 0x200100, 0, 0x100000);
   WriteEntry64(0x200100, 0, 0x200000, 0x300000);
   WriteDex(0x300000);
@@ -218,7 +222,7 @@
   uint64_t method_offset = 0x124;
   MapInfo* info = maps_->Get(kMapDexFiles);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x100800, 0x200000);
   WriteEntry32(0x200000, 0, 0, 0x300000);
   WriteDex(0x300000);
 
@@ -238,7 +242,7 @@
   uint64_t method_offset = 0x124;
   MapInfo* info = maps_->Get(kMapDexFiles);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x100800, 0x200000);
   WriteEntry32(0x200000, 0x200100, 0, 0x100000);
   WriteEntry32(0x200100, 0, 0x200000, 0x300000);
   WriteDex(0x300000);
@@ -274,9 +278,9 @@
   MapInfo* info = maps_->Get(kMapDexFiles);
 
   // First global variable found, but value is zero.
-  WriteDescriptor32(0xa800, 0);
+  WriteDescriptor32(0xc800, 0);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x100800, 0x200000);
   WriteEntry32(0x200000, 0, 0, 0x300000);
   WriteDex(0x300000);
 
@@ -289,7 +293,7 @@
   dex_files_->SetArch(ARCH_ARM);
   method_name = "fail";
   method_offset = 0x123;
-  WriteDescriptor32(0xa800, 0x100000);
+  WriteDescriptor32(0xc800, 0x100000);
   dex_files_->GetMethodInformation(maps_.get(), info, 0x300100, &method_name, &method_offset);
   EXPECT_EQ("fail", method_name);
   EXPECT_EQ(0x123U, method_offset);
@@ -303,9 +307,9 @@
   MapInfo* info = maps_->Get(kMapDexFiles);
 
   // First global variable found, but value is zero.
-  WriteDescriptor64(0xa800, 0);
+  WriteDescriptor64(0xc800, 0);
 
-  WriteDescriptor64(0xf800, 0x200000);
+  WriteDescriptor64(0x100800, 0x200000);
   WriteEntry64(0x200000, 0, 0, 0x300000);
   WriteDex(0x300000);
 
@@ -318,7 +322,7 @@
   dex_files_->SetArch(ARCH_ARM64);
   method_name = "fail";
   method_offset = 0x123;
-  WriteDescriptor64(0xa800, 0x100000);
+  WriteDescriptor64(0xc800, 0x100000);
   dex_files_->GetMethodInformation(maps_.get(), info, 0x300100, &method_name, &method_offset);
   EXPECT_EQ("fail", method_name);
   EXPECT_EQ(0x123U, method_offset);
diff --git a/libunwindstack/tests/ElfFake.h b/libunwindstack/tests/ElfFake.h
index 832e64a..c33908d 100644
--- a/libunwindstack/tests/ElfFake.h
+++ b/libunwindstack/tests/ElfFake.h
@@ -97,6 +97,14 @@
 
   void FakeSetErrorAddress(uint64_t address) { last_error_.address = address; }
 
+  void FakeSetDataOffset(uint64_t offset) { data_offset_ = offset; }
+  void FakeSetDataVaddrStart(uint64_t vaddr) { data_vaddr_start_ = vaddr; }
+  void FakeSetDataVaddrEnd(uint64_t vaddr) { data_vaddr_end_ = vaddr; }
+
+  void FakeSetDynamicOffset(uint64_t offset) { dynamic_offset_ = offset; }
+  void FakeSetDynamicVaddrStart(uint64_t vaddr) { dynamic_vaddr_start_ = vaddr; }
+  void FakeSetDynamicVaddrEnd(uint64_t vaddr) { dynamic_vaddr_end_ = vaddr; }
+
  private:
   std::unordered_map<std::string, uint64_t> globals_;
   std::string fake_build_id_;
diff --git a/libunwindstack/tests/ElfTest.cpp b/libunwindstack/tests/ElfTest.cpp
index e6728a0..d227b60 100644
--- a/libunwindstack/tests/ElfTest.cpp
+++ b/libunwindstack/tests/ElfTest.cpp
@@ -320,9 +320,13 @@
   MOCK_METHOD(bool, GetGlobalVariable, (const std::string&, uint64_t*), (override));
   MOCK_METHOD(bool, IsValidPc, (uint64_t), (override));
 
+  void MockSetDataOffset(uint64_t offset) { data_offset_ = offset; }
+  void MockSetDataVaddrStart(uint64_t vaddr) { data_vaddr_start_ = vaddr; }
+  void MockSetDataVaddrEnd(uint64_t vaddr) { data_vaddr_end_ = vaddr; }
+
   void MockSetDynamicOffset(uint64_t offset) { dynamic_offset_ = offset; }
-  void MockSetDynamicVaddr(uint64_t vaddr) { dynamic_vaddr_ = vaddr; }
-  void MockSetDynamicSize(uint64_t size) { dynamic_size_ = size; }
+  void MockSetDynamicVaddrStart(uint64_t vaddr) { dynamic_vaddr_start_ = vaddr; }
+  void MockSetDynamicVaddrEnd(uint64_t vaddr) { dynamic_vaddr_end_ = vaddr; }
 };
 
 TEST_F(ElfTest, step_in_interface) {
@@ -348,7 +352,7 @@
 
   std::string global("something");
   uint64_t offset;
-  ASSERT_FALSE(elf.GetGlobalVariable(global, &offset));
+  ASSERT_FALSE(elf.GetGlobalVariableOffset(global, &offset));
 }
 
 TEST_F(ElfTest, get_global_valid_not_in_interface) {
@@ -358,119 +362,69 @@
   ElfInterfaceMock* interface = new ElfInterfaceMock(memory_);
   elf.FakeSetInterface(interface);
 
-  uint64_t offset;
   std::string global("something");
-  EXPECT_CALL(*interface, GetGlobalVariable(global, &offset)).WillOnce(::testing::Return(false));
+  EXPECT_CALL(*interface, GetGlobalVariable(global, ::testing::_))
+      .WillOnce(::testing::Return(false));
 
-  ASSERT_FALSE(elf.GetGlobalVariable(global, &offset));
+  uint64_t offset;
+  ASSERT_FALSE(elf.GetGlobalVariableOffset(global, &offset));
 }
 
-TEST_F(ElfTest, get_global_valid_below_load_bias) {
+TEST_F(ElfTest, get_global_vaddr_in_no_sections) {
   ElfFake elf(memory_);
   elf.FakeSetValid(true);
-  elf.FakeSetLoadBias(0x1000);
 
   ElfInterfaceMock* interface = new ElfInterfaceMock(memory_);
   elf.FakeSetInterface(interface);
 
-  uint64_t offset;
   std::string global("something");
-  EXPECT_CALL(*interface, GetGlobalVariable(global, &offset))
+  EXPECT_CALL(*interface, GetGlobalVariable(global, ::testing::_))
       .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x300), ::testing::Return(true)));
 
-  ASSERT_FALSE(elf.GetGlobalVariable(global, &offset));
-}
-
-TEST_F(ElfTest, get_global_valid_dynamic_zero_non_zero_load_bias) {
-  ElfFake elf(memory_);
-  elf.FakeSetValid(true);
-  elf.FakeSetLoadBias(0x100);
-
-  ElfInterfaceMock* interface = new ElfInterfaceMock(memory_);
-  elf.FakeSetInterface(interface);
-
   uint64_t offset;
-  std::string global("something");
-  EXPECT_CALL(*interface, GetGlobalVariable(global, &offset))
-      .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x300), ::testing::Return(true)));
-
-  ASSERT_TRUE(elf.GetGlobalVariable(global, &offset));
-  EXPECT_EQ(0x200U, offset);
+  ASSERT_FALSE(elf.GetGlobalVariableOffset(global, &offset));
 }
 
-TEST_F(ElfTest, get_global_valid_dynamic_zero) {
+TEST_F(ElfTest, get_global_vaddr_in_data_section) {
   ElfFake elf(memory_);
   elf.FakeSetValid(true);
 
   ElfInterfaceMock* interface = new ElfInterfaceMock(memory_);
   elf.FakeSetInterface(interface);
+  interface->MockSetDataVaddrStart(0x500);
+  interface->MockSetDataVaddrEnd(0x600);
+  interface->MockSetDataOffset(0xa000);
 
-  ElfInterfaceMock* gnu_interface = new ElfInterfaceMock(memory_);
-  elf.FakeSetGnuDebugdataInterface(gnu_interface);
+  std::string global("something");
+  EXPECT_CALL(*interface, GetGlobalVariable(global, ::testing::_))
+      .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x580), ::testing::Return(true)));
 
   uint64_t offset;
-  std::string global("something");
-  EXPECT_CALL(*interface, GetGlobalVariable(global, &offset)).WillOnce(::testing::Return(false));
-
-  EXPECT_CALL(*gnu_interface, GetGlobalVariable(global, &offset))
-      .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x500), ::testing::Return(true)));
-
-  ASSERT_TRUE(elf.GetGlobalVariable(global, &offset));
-  EXPECT_EQ(0x500U, offset);
+  ASSERT_TRUE(elf.GetGlobalVariableOffset(global, &offset));
+  EXPECT_EQ(0xa080U, offset);
 }
 
-TEST_F(ElfTest, get_global_valid_in_gnu_debugdata_dynamic_zero) {
+TEST_F(ElfTest, get_global_vaddr_in_dynamic_section) {
   ElfFake elf(memory_);
   elf.FakeSetValid(true);
 
   ElfInterfaceMock* interface = new ElfInterfaceMock(memory_);
   elf.FakeSetInterface(interface);
+  interface->MockSetDataVaddrStart(0x500);
+  interface->MockSetDataVaddrEnd(0x600);
+  interface->MockSetDataOffset(0xa000);
+
+  interface->MockSetDynamicVaddrStart(0x800);
+  interface->MockSetDynamicVaddrEnd(0x900);
+  interface->MockSetDynamicOffset(0xc000);
+
+  std::string global("something");
+  EXPECT_CALL(*interface, GetGlobalVariable(global, ::testing::_))
+      .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x880), ::testing::Return(true)));
 
   uint64_t offset;
-  std::string global("something");
-  EXPECT_CALL(*interface, GetGlobalVariable(global, &offset))
-      .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x300), ::testing::Return(true)));
-
-  ASSERT_TRUE(elf.GetGlobalVariable(global, &offset));
-  EXPECT_EQ(0x300U, offset);
-}
-
-TEST_F(ElfTest, get_global_valid_dynamic_adjust_negative) {
-  ElfFake elf(memory_);
-  elf.FakeSetValid(true);
-
-  ElfInterfaceMock* interface = new ElfInterfaceMock(memory_);
-  interface->MockSetDynamicOffset(0x400);
-  interface->MockSetDynamicVaddr(0x800);
-  interface->MockSetDynamicSize(0x100);
-  elf.FakeSetInterface(interface);
-
-  uint64_t offset;
-  std::string global("something");
-  EXPECT_CALL(*interface, GetGlobalVariable(global, &offset))
-      .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x850), ::testing::Return(true)));
-
-  ASSERT_TRUE(elf.GetGlobalVariable(global, &offset));
-  EXPECT_EQ(0x450U, offset);
-}
-
-TEST_F(ElfTest, get_global_valid_dynamic_adjust_positive) {
-  ElfFake elf(memory_);
-  elf.FakeSetValid(true);
-
-  ElfInterfaceMock* interface = new ElfInterfaceMock(memory_);
-  interface->MockSetDynamicOffset(0x1000);
-  interface->MockSetDynamicVaddr(0x800);
-  interface->MockSetDynamicSize(0x100);
-  elf.FakeSetInterface(interface);
-
-  uint64_t offset;
-  std::string global("something");
-  EXPECT_CALL(*interface, GetGlobalVariable(global, &offset))
-      .WillOnce(::testing::DoAll(::testing::SetArgPointee<1>(0x850), ::testing::Return(true)));
-
-  ASSERT_TRUE(elf.GetGlobalVariable(global, &offset));
-  EXPECT_EQ(0x1050U, offset);
+  ASSERT_TRUE(elf.GetGlobalVariableOffset(global, &offset));
+  EXPECT_EQ(0xc080U, offset);
 }
 
 TEST_F(ElfTest, is_valid_pc_elf_invalid) {
diff --git a/libunwindstack/tests/JitDebugTest.cpp b/libunwindstack/tests/JitDebugTest.cpp
index b1ca111..9b32a3a 100644
--- a/libunwindstack/tests/JitDebugTest.cpp
+++ b/libunwindstack/tests/JitDebugTest.cpp
@@ -35,13 +35,17 @@
 
 class JitDebugTest : public ::testing::Test {
  protected:
-  void CreateFakeElf(MapInfo* map_info) {
+  void CreateFakeElf(MapInfo* map_info, uint64_t global_offset, uint64_t data_offset,
+                     uint64_t data_vaddr, uint64_t data_size) {
     MemoryFake* memory = new MemoryFake;
     ElfFake* elf = new ElfFake(memory);
     elf->FakeSetValid(true);
     ElfInterfaceFake* interface = new ElfInterfaceFake(memory);
     elf->FakeSetInterface(interface);
-    interface->FakeSetGlobalVariable("__jit_debug_descriptor", 0x800);
+    interface->FakeSetGlobalVariable("__jit_debug_descriptor", global_offset);
+    interface->FakeSetDataOffset(data_offset);
+    interface->FakeSetDataVaddrStart(data_vaddr);
+    interface->FakeSetDataVaddrEnd(data_vaddr + data_size);
     map_info->elf.reset(elf);
   }
 
@@ -52,27 +56,27 @@
     maps_.reset(
         new BufferMaps("1000-4000 ---s 00000000 00:00 0 /fake/elf1\n"
                        "4000-6000 r--s 00000000 00:00 0 /fake/elf1\n"
-                       "6000-8000 -wxs 00000000 00:00 0 /fake/elf1\n"
+                       "6000-8000 -wxs 00002000 00:00 0 /fake/elf1\n"
                        "a000-c000 --xp 00000000 00:00 0 /fake/elf2\n"
-                       "c000-f000 rw-p 00001000 00:00 0 /fake/elf2\n"
+                       "c000-f000 rw-p 00002000 00:00 0 /fake/elf2\n"
                        "f000-11000 r--p 00000000 00:00 0 /fake/elf3\n"
-                       "11000-12000 rw-p 00001000 00:00 0 /fake/elf3\n"
+                       "11000-12000 rw-p 00002000 00:00 0 /fake/elf3\n"
                        "12000-14000 r--p 00000000 00:00 0 /fake/elf4\n"
-                       "100000-110000 rw-p 0001000 00:00 0 /fake/elf4\n"
-                       "200000-210000 rw-p 0002000 00:00 0 /fake/elf4\n"));
+                       "100000-110000 rw-p 00ee000 00:00 0 /fake/elf4\n"
+                       "200000-210000 rw-p 01ee000 00:00 0 /fake/elf4\n"));
     ASSERT_TRUE(maps_->Parse());
 
     MapInfo* map_info = maps_->Get(3);
     ASSERT_TRUE(map_info != nullptr);
-    CreateFakeElf(map_info);
+    CreateFakeElf(map_info, 0x2800, 0x2000, 0x2000, 0x3000);
 
     map_info = maps_->Get(5);
     ASSERT_TRUE(map_info != nullptr);
-    CreateFakeElf(map_info);
+    CreateFakeElf(map_info, 0x2800, 0x2000, 0x2000, 0x3000);
 
     map_info = maps_->Get(7);
     ASSERT_TRUE(map_info != nullptr);
-    CreateFakeElf(map_info);
+    CreateFakeElf(map_info, 0xee800, 0xee000, 0xee000, 0x10000);
   }
 
   void SetUp() override {
@@ -258,7 +262,7 @@
 TEST_F(JitDebugTest, get_elf_no_valid_code_entry) {
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x11800, 0x200000);
 
   Elf* elf = jit_debug_->GetElf(maps_.get(), 0x1500);
   ASSERT_TRUE(elf == nullptr);
@@ -267,7 +271,7 @@
 TEST_F(JitDebugTest, get_elf_invalid_descriptor_first_entry) {
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
 
-  WriteDescriptor32(0xf800, 0);
+  WriteDescriptor32(0x11800, 0);
 
   Elf* elf = jit_debug_->GetElf(maps_.get(), 0x1500);
   ASSERT_TRUE(elf == nullptr);
@@ -276,9 +280,9 @@
 TEST_F(JitDebugTest, get_elf_invalid_descriptor_version) {
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
 
-  WriteDescriptor32(0xf800, 0x20000);
+  WriteDescriptor32(0x11800, 0x20000);
   // Set the version to an invalid value.
-  memory_->SetData32(0xf800, 2);
+  memory_->SetData32(0x11800, 2);
 
   Elf* elf = jit_debug_->GetElf(maps_.get(), 0x1500);
   ASSERT_TRUE(elf == nullptr);
@@ -287,7 +291,7 @@
 TEST_F(JitDebugTest, get_elf_32) {
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x11800, 0x200000);
   WriteEntry32Pad(0x200000, 0, 0, 0x4000, 0x1000);
 
   Elf* elf = jit_debug_->GetElf(maps_.get(), 0x1500);
@@ -304,16 +308,16 @@
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x5000, ELFCLASS32, EM_ARM, 0x2000, 0x300);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x11800, 0x200000);
   WriteEntry32Pad(0x200000, 0, 0, 0x4000, 0x1000);
-  WriteDescriptor32(0x12800, 0x201000);
+  WriteDescriptor32(0x100800, 0x201000);
   WriteEntry32Pad(0x201000, 0, 0, 0x5000, 0x1000);
 
   ASSERT_TRUE(jit_debug_->GetElf(maps_.get(), 0x1500) != nullptr);
   ASSERT_TRUE(jit_debug_->GetElf(maps_.get(), 0x2000) == nullptr);
 
   // Now clear the descriptor entry for the first one.
-  WriteDescriptor32(0xf800, 0);
+  WriteDescriptor32(0x11800, 0);
   jit_debug_.reset(new JitDebug(process_memory_));
   jit_debug_->SetArch(ARCH_ARM);
 
@@ -326,7 +330,7 @@
 
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x11800, 0x200000);
   WriteEntry32Pack(0x200000, 0, 0, 0x4000, 0x1000);
 
   jit_debug_->SetArch(ARCH_X86);
@@ -345,7 +349,7 @@
 
   CreateElf<Elf64_Ehdr, Elf64_Shdr>(0x4000, ELFCLASS64, EM_AARCH64, 0x1500, 0x200);
 
-  WriteDescriptor64(0xf800, 0x200000);
+  WriteDescriptor64(0x11800, 0x200000);
   WriteEntry64(0x200000, 0, 0, 0x4000, 0x1000);
 
   Elf* elf = jit_debug_->GetElf(maps_.get(), 0x1500);
@@ -362,7 +366,7 @@
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x5000, ELFCLASS32, EM_ARM, 0x2300, 0x400);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x11800, 0x200000);
   WriteEntry32Pad(0x200000, 0, 0x200100, 0x4000, 0x1000);
   WriteEntry32Pad(0x200100, 0x200100, 0, 0x5000, 0x1000);
 
@@ -385,7 +389,7 @@
 TEST_F(JitDebugTest, get_elf_search_libs) {
   CreateElf<Elf32_Ehdr, Elf32_Shdr>(0x4000, ELFCLASS32, EM_ARM, 0x1500, 0x200);
 
-  WriteDescriptor32(0xf800, 0x200000);
+  WriteDescriptor32(0x11800, 0x200000);
   WriteEntry32Pad(0x200000, 0, 0, 0x4000, 0x1000);
 
   // Only search a given named list of libs.
diff --git a/libunwindstack/tests/files/offline/art_quick_osr_stub_arm/maps.txt b/libunwindstack/tests/files/offline/art_quick_osr_stub_arm/maps.txt
index 5657373..1ff12db 100644
--- a/libunwindstack/tests/files/offline/art_quick_osr_stub_arm/maps.txt
+++ b/libunwindstack/tests/files/offline/art_quick_osr_stub_arm/maps.txt
@@ -1,4 +1,4 @@
 d0250000-d2600000 r-xp 0 00:00 0 <anonymous:d0250000>
 e466e000-e4ae8000 r-xp 0 00:00 0 libart.so
-e4ae8000-e4ae9000 rw-p 1000 00:00 0 libart.so
+e4af1000-e4af2000 rw-p 482000 00:00 0 libart.so
 e7d91000-e7e31000 r-xp 0 00:00 0 libc.so
diff --git a/libunwindstack/tests/files/offline/jit_debug_arm/maps.txt b/libunwindstack/tests/files/offline/jit_debug_arm/maps.txt
index 4043122..3b87f2f 100644
--- a/libunwindstack/tests/files/offline/jit_debug_arm/maps.txt
+++ b/libunwindstack/tests/files/offline/jit_debug_arm/maps.txt
@@ -4,8 +4,8 @@
 e0447000-e0448000 r-xp 2000 00:00 0   137-cfi.odex
 e2796000-e4796000 r-xp 0 00:00 0   anonymous:e2796000
 e648e000-e690f000 r-xp 0 00:00 0  libart.so
-e690f000-e6910000 rw-p 1000 00:00 0  libart.so
+e6918000-e6919000 rw-p 489000 00:00 0  libart.so
 ed306000-ed801000 r-xp 0 00:00 0   libartd.so
-ed801000-ed802000 rw-p 1000 00:00 0   libartd.so
+ed80a000-ed80b000 rw-p 503000 00:00 0   libartd.so
 eda88000-edb23000 r-xp 0 00:00 0   libc.so
 ede4e000-ede50000 r-xp 0 00:00 0   anonymous:ede4e000
diff --git a/libunwindstack/tests/files/offline/jit_debug_x86/maps.txt b/libunwindstack/tests/files/offline/jit_debug_x86/maps.txt
index f255a44..c22b5de 100644
--- a/libunwindstack/tests/files/offline/jit_debug_x86/maps.txt
+++ b/libunwindstack/tests/files/offline/jit_debug_x86/maps.txt
@@ -4,5 +4,5 @@
 ec606000-ec607000 r-xp 2000 00:00 0   137-cfi.odex
 ee74c000-f074c000 r-xp 0 00:00 0   anonymous:ee74c000
 f6be1000-f732b000 r-xp 0 00:00 0   libartd.so
-f732b000-f732c000 rw-p 1000 00:00 0   libartd.so
+f7334000-f7335000 rw-p 752000 00:00 0   libartd.so
 f734b000-f74fc000 r-xp 0 00:00 0   libc.so
diff --git a/libutils/StrongPointer.cpp b/libutils/StrongPointer.cpp
index ba52502..ef46723 100644
--- a/libutils/StrongPointer.cpp
+++ b/libutils/StrongPointer.cpp
@@ -21,4 +21,7 @@
 namespace android {
 
 void sp_report_race() { LOG_ALWAYS_FATAL("sp<> assignment detected data race"); }
+
+void sp_report_stack_pointer() { LOG_ALWAYS_FATAL("sp<> constructed with stack pointer argument"); }
+
 }
diff --git a/libutils/include/utils/StrongPointer.h b/libutils/include/utils/StrongPointer.h
index 9cd7c75..07dd3f1 100644
--- a/libutils/include/utils/StrongPointer.h
+++ b/libutils/include/utils/StrongPointer.h
@@ -122,26 +122,54 @@
         return o != *this;
     }
 
-private:    
+private:
     template<typename Y> friend class sp;
     template<typename Y> friend class wp;
     void set_pointer(T* ptr);
+    static inline void check_not_on_stack(const void* ptr);
     T* m_ptr;
 };
 
-// For code size reasons, we do not want this inlined or templated.
+// For code size reasons, we do not want these inlined or templated.
 void sp_report_race();
+void sp_report_stack_pointer();
 
 #undef COMPARE
 
 // ---------------------------------------------------------------------------
 // No user serviceable parts below here.
 
+// Check whether address is definitely on the calling stack.  We actually check whether it is on
+// the same 4K page as the frame pointer.
+//
+// Assumptions:
+// - Pages are never smaller than 4K (MIN_PAGE_SIZE)
+// - Malloced memory never shares a page with a stack.
+//
+// It does not appear safe to broaden this check to include adjacent pages; apparently this code
+// is used in environments where there may not be a guard page below (at higher addresses than)
+// the bottom of the stack.
+//
+// TODO: Consider adding make_sp<T>() to allocate an object and wrap the resulting pointer safely
+// without checking overhead.
+template <typename T>
+void sp<T>::check_not_on_stack(const void* ptr) {
+    static constexpr int MIN_PAGE_SIZE = 0x1000;  // 4K. Safer than including sys/user.h.
+    static constexpr uintptr_t MIN_PAGE_MASK = ~static_cast<uintptr_t>(MIN_PAGE_SIZE - 1);
+    uintptr_t my_frame_address =
+            reinterpret_cast<uintptr_t>(__builtin_frame_address(0 /* this frame */));
+    if (((reinterpret_cast<uintptr_t>(ptr) ^ my_frame_address) & MIN_PAGE_MASK) == 0) {
+        sp_report_stack_pointer();
+    }
+}
+
 template<typename T>
 sp<T>::sp(T* other)
         : m_ptr(other) {
-    if (other)
+    if (other) {
+        check_not_on_stack(other);
         other->incStrong(this);
+    }
 }
 
 template<typename T>
@@ -159,8 +187,10 @@
 template<typename T> template<typename U>
 sp<T>::sp(U* other)
         : m_ptr(other) {
-    if (other)
+    if (other) {
+        check_not_on_stack(other);
         (static_cast<T*>(other))->incStrong(this);
+    }
 }
 
 template<typename T> template<typename U>
@@ -207,7 +237,10 @@
 template<typename T>
 sp<T>& sp<T>::operator =(T* other) {
     T* oldPtr(*const_cast<T* volatile*>(&m_ptr));
-    if (other) other->incStrong(this);
+    if (other) {
+        check_not_on_stack(other);
+        other->incStrong(this);
+    }
     if (oldPtr) oldPtr->decStrong(this);
     if (oldPtr != *const_cast<T* volatile*>(&m_ptr)) sp_report_race();
     m_ptr = other;