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/*
* Copyright (C) 2016 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.
*/
#ifndef ART_RUNTIME_VDEX_FILE_H_
#define ART_RUNTIME_VDEX_FILE_H_
#include <stdint.h>
#include <string>
#include "base/array_ref.h"
#include "base/macros.h"
#include "base/mem_map.h"
#include "base/os.h"
#include "dex/compact_offset_table.h"
#include "dex/dex_file.h"
#include "quicken_info.h"
namespace art {
class ClassLoaderContext;
namespace verifier {
class VerifierDeps;
} // namespace verifier
// VDEX files contain extracted DEX files. The VdexFile class maps the file to
// memory and provides tools for accessing its individual sections.
//
// File format:
// VdexFile::VerifierDepsHeader fixed-length header
// Dex file checksums
//
// Optionally:
// VdexFile::DexSectionHeader fixed-length header
//
// quicken_table_off[0] offset into QuickeningInfo section for offset table for DEX[0].
// DEX[0] array of the input DEX files, the bytecode may have been quickened.
// quicken_table_off[1]
// DEX[1]
// ...
// DEX[D]
//
// VerifierDeps
// uint8[D][] verification dependencies
//
// Optionally:
// QuickeningInfo
// uint8[D][] quickening data
// uint32[D][] quickening data offset tables
class VdexFile {
public:
using VdexChecksum = uint32_t;
using QuickeningTableOffsetType = uint32_t;
struct VerifierDepsHeader {
public:
VerifierDepsHeader(uint32_t number_of_dex_files_,
uint32_t verifier_deps_size,
bool has_dex_section,
uint32_t bootclasspath_checksums_size = 0,
uint32_t class_loader_context_size = 0);
const char* GetMagic() const { return reinterpret_cast<const char*>(magic_); }
const char* GetVerifierDepsVersion() const {
return reinterpret_cast<const char*>(verifier_deps_version_);
}
const char* GetDexSectionVersion() const {
return reinterpret_cast<const char*>(dex_section_version_);
}
bool IsMagicValid() const;
bool IsVerifierDepsVersionValid() const;
bool IsDexSectionVersionValid() const;
bool IsValid() const {
return IsMagicValid() && IsVerifierDepsVersionValid() && IsDexSectionVersionValid();
}
bool HasDexSection() const;
uint32_t GetVerifierDepsSize() const { return verifier_deps_size_; }
uint32_t GetNumberOfDexFiles() const { return number_of_dex_files_; }
uint32_t GetBootClassPathChecksumStringSize() const { return bootclasspath_checksums_size_; }
uint32_t GetClassLoaderContextStringSize() const { return class_loader_context_size_; }
size_t GetSizeOfChecksumsSection() const {
return sizeof(VdexChecksum) * GetNumberOfDexFiles();
}
const VdexChecksum* GetDexChecksumsArray() const {
return reinterpret_cast<const VdexChecksum*>(
reinterpret_cast<const uint8_t*>(this) + sizeof(VerifierDepsHeader));
}
VdexChecksum GetDexChecksumAtOffset(size_t idx) const {
DCHECK_LT(idx, GetNumberOfDexFiles());
return GetDexChecksumsArray()[idx];
}
static constexpr uint8_t kVdexInvalidMagic[] = { 'w', 'd', 'e', 'x' };
private:
static constexpr uint8_t kVdexMagic[] = { 'v', 'd', 'e', 'x' };
// The format version of the verifier deps header and the verifier deps.
// Last update: Add boot checksum, class loader context.
static constexpr uint8_t kVerifierDepsVersion[] = { '0', '2', '1', '\0' };
// The format version of the dex section header and the dex section, containing
// both the dex code and the quickening data.
// Last update: Add owned section for CompactDex.
static constexpr uint8_t kDexSectionVersion[] = { '0', '0', '2', '\0' };
// If the .vdex file has no dex section (hence no dex code nor quickening data),
// we encode this magic version.
static constexpr uint8_t kDexSectionVersionEmpty[] = { '0', '0', '0', '\0' };
uint8_t magic_[4];
uint8_t verifier_deps_version_[4];
uint8_t dex_section_version_[4];
uint32_t number_of_dex_files_;
uint32_t verifier_deps_size_;
uint32_t bootclasspath_checksums_size_;
uint32_t class_loader_context_size_;
};
struct DexSectionHeader {
public:
DexSectionHeader(uint32_t dex_size,
uint32_t dex_shared_data_size,
uint32_t quickening_info_size);
uint32_t GetDexSize() const { return dex_size_; }
uint32_t GetDexSharedDataSize() const { return dex_shared_data_size_; }
uint32_t GetQuickeningInfoSize() const { return quickening_info_size_; }
size_t GetDexSectionSize() const {
return sizeof(DexSectionHeader) +
GetDexSize() +
GetDexSharedDataSize();
}
private:
uint32_t dex_size_;
uint32_t dex_shared_data_size_;
uint32_t quickening_info_size_;
friend class VdexFile; // For updating quickening_info_size_.
};
size_t GetComputedFileSize() const {
size_t size = sizeof(VerifierDepsHeader);
const VerifierDepsHeader& header = GetVerifierDepsHeader();
size += header.GetVerifierDepsSize();
size += header.GetSizeOfChecksumsSection();
if (header.HasDexSection()) {
size += GetDexSectionHeader().GetDexSectionSize();
size += GetDexSectionHeader().GetQuickeningInfoSize();
}
size += header.GetBootClassPathChecksumStringSize();
size += header.GetClassLoaderContextStringSize();
return size;
}
// Note: The file is called "primary" to match the naming with profiles.
static const constexpr char* kVdexNameInDmFile = "primary.vdex";
explicit VdexFile(MemMap&& mmap) : mmap_(std::move(mmap)) {}
// Returns nullptr if the vdex file cannot be opened or is not valid.
// The mmap_* parameters can be left empty (nullptr/0/false) to allocate at random address.
static std::unique_ptr<VdexFile> OpenAtAddress(uint8_t* mmap_addr,
size_t mmap_size,
bool mmap_reuse,
const std::string& vdex_filename,
bool writable,
bool low_4gb,
bool unquicken,
std::string* error_msg);
// Returns nullptr if the vdex file cannot be opened or is not valid.
// The mmap_* parameters can be left empty (nullptr/0/false) to allocate at random address.
static std::unique_ptr<VdexFile> OpenAtAddress(uint8_t* mmap_addr,
size_t mmap_size,
bool mmap_reuse,
int file_fd,
size_t vdex_length,
const std::string& vdex_filename,
bool writable,
bool low_4gb,
bool unquicken,
std::string* error_msg);
// Returns nullptr if the vdex file cannot be opened or is not valid.
static std::unique_ptr<VdexFile> Open(const std::string& vdex_filename,
bool writable,
bool low_4gb,
bool unquicken,
std::string* error_msg) {
return OpenAtAddress(nullptr,
0,
false,
vdex_filename,
writable,
low_4gb,
unquicken,
error_msg);
}
// Returns nullptr if the vdex file cannot be opened or is not valid.
static std::unique_ptr<VdexFile> Open(int file_fd,
size_t vdex_length,
const std::string& vdex_filename,
bool writable,
bool low_4gb,
bool unquicken,
std::string* error_msg) {
return OpenAtAddress(nullptr,
0,
false,
file_fd,
vdex_length,
vdex_filename,
writable,
low_4gb,
unquicken,
error_msg);
}
const uint8_t* Begin() const { return mmap_.Begin(); }
const uint8_t* End() const { return mmap_.End(); }
size_t Size() const { return mmap_.Size(); }
const VerifierDepsHeader& GetVerifierDepsHeader() const {
return *reinterpret_cast<const VerifierDepsHeader*>(Begin());
}
uint32_t GetDexSectionHeaderOffset() const {
return sizeof(VerifierDepsHeader) + GetVerifierDepsHeader().GetSizeOfChecksumsSection();
}
const DexSectionHeader& GetDexSectionHeader() const {
DCHECK(GetVerifierDepsHeader().HasDexSection());
return *reinterpret_cast<const DexSectionHeader*>(Begin() + GetDexSectionHeaderOffset());
}
const uint8_t* GetVerifierDepsStart() const {
const uint8_t* result = Begin() + GetDexSectionHeaderOffset();
if (GetVerifierDepsHeader().HasDexSection()) {
// When there is a dex section, the verifier deps are after it, but before the quickening.
return result + GetDexSectionHeader().GetDexSectionSize();
} else {
// When there is no dex section, the verifier deps are just after the header.
return result;
}
}
ArrayRef<const uint8_t> GetVerifierDepsData() const {
return ArrayRef<const uint8_t>(
GetVerifierDepsStart(),
GetVerifierDepsHeader().GetVerifierDepsSize());
}
ArrayRef<const uint8_t> GetQuickeningInfo() const {
return ArrayRef<const uint8_t>(
GetVerifierDepsData().end(),
GetVerifierDepsHeader().HasDexSection()
? GetDexSectionHeader().GetQuickeningInfoSize() : 0);
}
ArrayRef<const uint8_t> GetBootClassPathChecksumData() const {
return ArrayRef<const uint8_t>(
GetQuickeningInfo().end(),
GetVerifierDepsHeader().GetBootClassPathChecksumStringSize());
}
ArrayRef<const uint8_t> GetClassLoaderContextData() const {
return ArrayRef<const uint8_t>(
GetBootClassPathChecksumData().end(),
GetVerifierDepsHeader().GetClassLoaderContextStringSize());
}
bool IsValid() const {
return mmap_.Size() >= sizeof(VerifierDepsHeader) && GetVerifierDepsHeader().IsValid();
}
// This method is for iterating over the dex files in the vdex. If `cursor` is null,
// the first dex file is returned. If `cursor` is not null, it must point to a dex
// file and this method returns the next dex file if there is one, or null if there
// is none.
const uint8_t* GetNextDexFileData(const uint8_t* cursor) const;
// Get the location checksum of the dex file number `dex_file_index`.
uint32_t GetLocationChecksum(uint32_t dex_file_index) const {
DCHECK_LT(dex_file_index, GetVerifierDepsHeader().GetNumberOfDexFiles());
return reinterpret_cast<const uint32_t*>(Begin() + sizeof(VerifierDepsHeader))[dex_file_index];
}
// Open all the dex files contained in this vdex file.
bool OpenAllDexFiles(std::vector<std::unique_ptr<const DexFile>>* dex_files,
std::string* error_msg) const;
// In-place unquicken the given `dex_files` based on `quickening_info`.
// `decompile_return_instruction` controls if RETURN_VOID_BARRIER instructions are
// decompiled to RETURN_VOID instructions using the slower ClassAccessor instead of the faster
// QuickeningInfoIterator.
// Always unquickens using the vdex dex files as the source for quicken tables.
void Unquicken(const std::vector<const DexFile*>& target_dex_files,
bool decompile_return_instruction) const;
void UnquickenInPlace(bool decompile_return_instruction) const;
// Fully unquicken `target_dex_file` based on `quickening_info`.
void UnquickenDexFile(const DexFile& target_dex_file,
const DexFile& source_dex_file,
bool decompile_return_instruction) const;
// Return the quickening info of a given method index (or null if it's empty).
ArrayRef<const uint8_t> GetQuickenedInfoOf(const DexFile& dex_file,
uint32_t dex_method_idx) const;
bool HasDexSection() const {
return GetVerifierDepsHeader().HasDexSection();
}
// Writes a vdex into `path` and returns true on success.
// The vdex will not contain a dex section but will store checksums of `dex_files`,
// encoded `verifier_deps`, as well as the current boot class path cheksum and
// encoded `class_loader_context`.
static bool WriteToDisk(const std::string& path,
const std::vector<const DexFile*>& dex_files,
const verifier::VerifierDeps& verifier_deps,
const std::string& class_loader_context,
std::string* error_msg);
// Returns true if the dex file checksums stored in the vdex header match
// the checksums in `dex_headers`. Both the number of dex files and their
// order must match too.
bool MatchesDexFileChecksums(const std::vector<const DexFile::Header*>& dex_headers) const;
// Returns true if the boot class path checksum stored in the vdex matches
// the checksum of boot class path in the current runtime.
bool MatchesBootClassPathChecksums() const;
// Returns true if the class loader context stored in the vdex matches `context`.
bool MatchesClassLoaderContext(const ClassLoaderContext& context) const;
// Make the Vdex file & underlying dex-files RW or RO. Should only be used for in-place
// dequickening.
void AllowWriting(bool value) const;
private:
uint32_t GetQuickeningInfoTableOffset(const uint8_t* source_dex_begin) const;
// Source dex must be the in the vdex file.
void UnquickenDexFile(const DexFile& target_dex_file,
const uint8_t* source_dex_begin,
bool decompile_return_instruction) const;
CompactOffsetTable::Accessor GetQuickenInfoOffsetTable(
const DexFile& dex_file,
const ArrayRef<const uint8_t>& quickening_info) const;
CompactOffsetTable::Accessor GetQuickenInfoOffsetTable(
const uint8_t* source_dex_begin,
const ArrayRef<const uint8_t>& quickening_info) const;
bool ContainsDexFile(const DexFile& dex_file) const;
const uint8_t* DexBegin() const {
DCHECK(HasDexSection());
return Begin() + GetDexSectionHeaderOffset() + sizeof(DexSectionHeader);
}
const uint8_t* DexEnd() const {
DCHECK(HasDexSection());
return DexBegin() + GetDexSectionHeader().GetDexSize();
}
// mutable for AllowWriting()
mutable MemMap mmap_;
DISALLOW_COPY_AND_ASSIGN(VdexFile);
};
} // namespace art
#endif // ART_RUNTIME_VDEX_FILE_H_