Unquicken dex files before exporting from oatdump
Benefit from the vdex unquicken method when exporting dex files from
oatdump (--export-dex-to). Currently oatdump exports the quickened dex
files as generated by the dex compiler (dex-to-dex transformations).
With this commit the dex files associated with the input oat file are
unquickened before exporting.
In contrast to the other VdexFile::Unquicken() calls, in this case it
is useful to decompile a RETURN_VOID_NO_BARRIER into a RETURN_VOID. As
such, the required changes around the decompile_return_instruction flag
were made since it was hardcoded to false.
This feature is mostly useful when inspecting oat files that have the
original bytecode being stripped from the matching APK. If unquicken
is successful, the old checksum is expected to match.
Test: test-art-host
Change-Id: I9133d5f488ee3451c8f361ae90d1e12857529b1e
Signed-off-by: Anestis Bechtsoudis <anestis@census-labs.com>
diff --git a/oatdump/oatdump.cc b/oatdump/oatdump.cc
index bcf007b..bdc36e8 100644
--- a/oatdump/oatdump.cc
+++ b/oatdump/oatdump.cc
@@ -412,6 +412,8 @@
return instruction_set_;
}
+ typedef std::vector<std::unique_ptr<const DexFile>> DexFileUniqV;
+
bool Dump(std::ostream& os) {
bool success = true;
const OatHeader& oat_header = oat_file_.GetOatHeader();
@@ -563,14 +565,50 @@
for (size_t i = 0; i < oat_dex_files_.size(); i++) {
const OatFile::OatDexFile* oat_dex_file = oat_dex_files_[i];
CHECK(oat_dex_file != nullptr);
+ if (!DumpOatDexFile(os, *oat_dex_file)) {
+ success = false;
+ }
+ }
+ }
- // If file export selected skip file analysis
- if (options_.export_dex_location_) {
- if (!ExportDexFile(os, *oat_dex_file)) {
+ if (options_.export_dex_location_) {
+ if (kIsVdexEnabled) {
+ std::string error_msg;
+ std::string vdex_filename = GetVdexFilename(oat_file_.GetLocation());
+ if (!OS::FileExists(vdex_filename.c_str())) {
+ os << "File " << vdex_filename.c_str() << " does not exist\n";
+ return false;
+ }
+
+ DexFileUniqV vdex_dex_files;
+ std::unique_ptr<const VdexFile> vdex_file = OpenVdexUnquicken(vdex_filename,
+ &vdex_dex_files,
+ &error_msg);
+ if (vdex_file.get() == nullptr) {
+ os << "Failed to open vdex file: " << error_msg << "\n";
+ return false;
+ }
+ if (oat_dex_files_.size() != vdex_dex_files.size()) {
+ os << "Dex files number in Vdex file does not match Dex files number in Oat file: "
+ << vdex_dex_files.size() << " vs " << oat_dex_files_.size() << '\n';
+ return false;
+ }
+
+ size_t i = 0;
+ for (const auto& vdex_dex_file : vdex_dex_files) {
+ const OatFile::OatDexFile* oat_dex_file = oat_dex_files_[i];
+ CHECK(oat_dex_file != nullptr);
+ CHECK(vdex_dex_file != nullptr);
+ if (!ExportDexFile(os, *oat_dex_file, vdex_dex_file.get())) {
success = false;
}
- } else {
- if (!DumpOatDexFile(os, *oat_dex_file)) {
+ i++;
+ }
+ } else {
+ for (size_t i = 0; i < oat_dex_files_.size(); i++) {
+ const OatFile::OatDexFile* oat_dex_file = oat_dex_files_[i];
+ CHECK(oat_dex_file != nullptr);
+ if (!ExportDexFile(os, *oat_dex_file, /* vdex_dex_file */ nullptr)) {
success = false;
}
}
@@ -628,6 +666,57 @@
return nullptr;
}
+ // Returns nullptr and updates error_msg if the Vdex file cannot be opened, otherwise all Dex
+ // files are fully unquickened and stored in dex_files
+ std::unique_ptr<const VdexFile> OpenVdexUnquicken(const std::string& vdex_filename,
+ /* out */ DexFileUniqV* dex_files,
+ /* out */ std::string* error_msg) {
+ std::unique_ptr<const File> file(OS::OpenFileForReading(vdex_filename.c_str()));
+ if (file == nullptr) {
+ *error_msg = "Could not open file " + vdex_filename + " for reading.";
+ return nullptr;
+ }
+
+ int64_t vdex_length = file->GetLength();
+ if (vdex_length == -1) {
+ *error_msg = "Could not read the length of file " + vdex_filename;
+ return nullptr;
+ }
+
+ std::unique_ptr<MemMap> mmap(MemMap::MapFile(
+ file->GetLength(),
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE,
+ file->Fd(),
+ /* start offset */ 0,
+ /* low_4gb */ false,
+ vdex_filename.c_str(),
+ error_msg));
+ if (mmap == nullptr) {
+ *error_msg = "Failed to mmap file " + vdex_filename + ": " + *error_msg;
+ return nullptr;
+ }
+
+ std::unique_ptr<VdexFile> vdex_file(new VdexFile(mmap.release()));
+ if (!vdex_file->IsValid()) {
+ *error_msg = "Vdex file is not valid";
+ return nullptr;
+ }
+
+ DexFileUniqV tmp_dex_files;
+ if (!vdex_file->OpenAllDexFiles(&tmp_dex_files, error_msg)) {
+ *error_msg = "Failed to open Dex files from Vdex: " + *error_msg;
+ return nullptr;
+ }
+
+ vdex_file->Unquicken(MakeNonOwningPointerVector(tmp_dex_files),
+ vdex_file->GetQuickeningInfo(),
+ /* decompile_return_instruction */ true);
+
+ *dex_files = std::move(tmp_dex_files);
+ return vdex_file;
+ }
+
struct Stats {
enum ByteKind {
kByteKindCode,
@@ -1024,15 +1113,15 @@
return success;
}
- bool ExportDexFile(std::ostream& os, const OatFile::OatDexFile& oat_dex_file) {
+ // Backwards compatible Dex file export. If dex_file is nullptr (valid Vdex file not present) the
+ // Dex resource is extracted from the oat_dex_file and its checksum is repaired since it's not
+ // unquickened. Otherwise the dex_file has been fully unquickened and is expected to verify the
+ // original checksum.
+ bool ExportDexFile(std::ostream& os,
+ const OatFile::OatDexFile& oat_dex_file,
+ const DexFile* dex_file) {
std::string error_msg;
std::string dex_file_location = oat_dex_file.GetDexFileLocation();
-
- const DexFile* const dex_file = OpenDexFile(&oat_dex_file, &error_msg);
- if (dex_file == nullptr) {
- os << "Failed to open dex file '" << dex_file_location << "': " << error_msg;
- return false;
- }
size_t fsize = oat_dex_file.FileSize();
// Some quick checks just in case
@@ -1041,6 +1130,27 @@
return false;
}
+ if (dex_file == nullptr) {
+ // Exported bytecode is quickened (dex-to-dex transformations present)
+ dex_file = OpenDexFile(&oat_dex_file, &error_msg);
+ if (dex_file == nullptr) {
+ os << "Failed to open dex file '" << dex_file_location << "': " << error_msg;
+ return false;
+ }
+
+ // Recompute checksum
+ reinterpret_cast<DexFile::Header*>(const_cast<uint8_t*>(dex_file->Begin()))->checksum_ =
+ dex_file->CalculateChecksum();
+ } else {
+ // Vdex unquicken output should match original input bytecode
+ uint32_t orig_checksum =
+ reinterpret_cast<DexFile::Header*>(const_cast<uint8_t*>(dex_file->Begin()))->checksum_;
+ if (orig_checksum != dex_file->CalculateChecksum()) {
+ os << "Unexpected checksum from unquicken dex file '" << dex_file_location << "'\n";
+ return false;
+ }
+ }
+
// Verify output directory exists
if (!OS::DirectoryExists(options_.export_dex_location_)) {
// TODO: Extend OS::DirectoryExists if symlink support is required