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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 "class_status.h"
#include "dex/compact_offset_table.h"
#include "dex/dex_file.h"
#include "handle.h"
namespace art HIDDEN {
class ClassLoaderContext;
class Thread;
namespace mirror {
class Class;
}
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.
//
// In the description below, D is the number of dex files.
//
// File format:
// VdexFileHeader fixed-length header
// VdexSectionHeader[kNumberOfSections]
//
// Checksum section
// VdexChecksum[D]
//
// Optionally:
// DexSection
// DEX[0] array of the input DEX files
// DEX[1]
// ...
// DEX[D-1]
//
// VerifierDeps
// 4-byte alignment
// uint32[D] DexFileDeps offsets for each dex file
// DexFileDeps[D][] verification dependencies
// 4-byte alignment
// uint32[class_def_size] TypeAssignability offsets (kNotVerifiedMarker for a class
// that isn't verified)
// uint32 Offset of end of AssignabilityType sets
// uint8[] AssignabilityType sets
// 4-byte alignment
// uint32 Number of strings
// uint32[] String data offsets for each string
// uint8[] String data
enum VdexSection : uint32_t {
kChecksumSection = 0,
kDexFileSection = 1,
kVerifierDepsSection = 2,
kTypeLookupTableSection = 3,
kNumberOfSections = 4,
};
class VdexFile {
public:
using VdexChecksum = uint32_t;
struct VdexSectionHeader {
VdexSection section_kind;
uint32_t section_offset;
uint32_t section_size;
VdexSectionHeader(VdexSection kind, uint32_t offset, uint32_t size)
: section_kind(kind), section_offset(offset), section_size(size) {}
VdexSectionHeader() {}
};
struct VdexFileHeader {
public:
EXPORT explicit VdexFileHeader(bool has_dex_section);
const char* GetMagic() const { return reinterpret_cast<const char*>(magic_); }
const char* GetVdexVersion() const {
return reinterpret_cast<const char*>(vdex_version_);
}
uint32_t GetNumberOfSections() const {
return number_of_sections_;
}
EXPORT bool IsMagicValid() const;
EXPORT bool IsVdexVersionValid() const;
bool IsValid() const {
return IsMagicValid() && IsVdexVersionValid();
}
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: Introduce vdex sections.
static constexpr uint8_t kVdexVersion[] = { '0', '2', '7', '\0' };
uint8_t magic_[4];
uint8_t vdex_version_[4];
uint32_t number_of_sections_;
};
const VdexSectionHeader& GetSectionHeaderAt(uint32_t index) const {
DCHECK_LT(index, GetVdexFileHeader().GetNumberOfSections());
return *reinterpret_cast<const VdexSectionHeader*>(
Begin() + sizeof(VdexFileHeader) + index * sizeof(VdexSectionHeader));
}
const VdexSectionHeader& GetSectionHeader(VdexSection kind) const {
return GetSectionHeaderAt(static_cast<uint32_t>(kind));
}
static size_t GetChecksumsOffset() {
return sizeof(VdexFileHeader) +
static_cast<size_t>(VdexSection::kNumberOfSections) * sizeof(VdexSectionHeader);
}
size_t GetComputedFileSize() const {
const VdexFileHeader& header = GetVdexFileHeader();
uint32_t size = sizeof(VdexFileHeader) +
header.GetNumberOfSections() * sizeof(VdexSectionHeader);
for (uint32_t i = 0; i < header.GetNumberOfSections(); ++i) {
size = std::max(size,
GetSectionHeaderAt(i).section_offset + GetSectionHeaderAt(i).section_size);
}
return size;
}
bool HasDexSection() const {
return GetSectionHeader(VdexSection::kDexFileSection).section_size != 0u;
}
uint32_t GetVerifierDepsSize() const {
return GetSectionHeader(VdexSection::kVerifierDepsSection).section_size;
}
uint32_t GetNumberOfDexFiles() const {
return GetSectionHeader(VdexSection::kChecksumSection).section_size / sizeof(VdexChecksum);
}
bool HasTypeLookupTableSection() const {
return GetVdexFileHeader().GetNumberOfSections() >= (kTypeLookupTableSection + 1);
}
const VdexChecksum* GetDexChecksumsArray() const {
return reinterpret_cast<const VdexChecksum*>(
Begin() + GetSectionHeader(VdexSection::kChecksumSection).section_offset);
}
VdexChecksum GetDexChecksumAt(size_t idx) const {
DCHECK_LT(idx, GetNumberOfDexFiles());
return GetDexChecksumsArray()[idx];
}
// 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.
EXPORT 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,
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.
EXPORT 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,
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,
std::string* error_msg) {
return OpenAtAddress(nullptr,
0,
false,
vdex_filename,
writable,
low_4gb,
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,
std::string* error_msg) {
return OpenAtAddress(nullptr,
0,
false,
file_fd,
vdex_length,
vdex_filename,
writable,
low_4gb,
error_msg);
}
EXPORT static std::unique_ptr<VdexFile> OpenFromDm(const std::string& filename,
const ZipArchive& archive);
const uint8_t* Begin() const { return mmap_.Begin(); }
const uint8_t* End() const { return mmap_.End(); }
size_t Size() const { return mmap_.Size(); }
bool Contains(const uint8_t* pointer, size_t size) const {
return Begin() <= pointer && size <= Size() && pointer <= End() - size;
}
const VdexFileHeader& GetVdexFileHeader() const {
return *reinterpret_cast<const VdexFileHeader*>(Begin());
}
ArrayRef<const uint8_t> GetVerifierDepsData() const {
return ArrayRef<const uint8_t>(
Begin() + GetSectionHeader(VdexSection::kVerifierDepsSection).section_offset,
GetSectionHeader(VdexSection::kVerifierDepsSection).section_size);
}
bool IsValid() const {
return mmap_.Size() >= sizeof(VdexFileHeader) && GetVdexFileHeader().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.
EXPORT const uint8_t* GetNextDexFileData(const uint8_t* cursor, uint32_t dex_file_index) const;
const uint8_t* GetNextTypeLookupTableData(const uint8_t* cursor, uint32_t dex_file_index) 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, GetNumberOfDexFiles());
return GetDexChecksumAt(dex_file_index);
}
// Open all the dex files contained in this vdex file.
EXPORT bool OpenAllDexFiles(std::vector<std::unique_ptr<const DexFile>>* dex_files,
std::string* error_msg) const;
// 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,
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 all dex files are standard dex rather than compact dex.
// Also returns true if there are no dex files at all.
bool HasOnlyStandardDexFiles() const;
ClassStatus ComputeClassStatus(Thread* self, Handle<mirror::Class> cls) const
REQUIRES_SHARED(Locks::mutator_lock_);
// Return the name of the underlying `MemMap` of the vdex file, typically the
// location on disk of the vdex file.
const std::string& GetName() const {
return mmap_.GetName();
}
private:
bool ContainsDexFile(const DexFile& dex_file) const;
const uint8_t* DexBegin() const {
DCHECK(HasDexSection());
return Begin() + GetSectionHeader(VdexSection::kDexFileSection).section_offset;
}
const uint8_t* TypeLookupTableDataBegin() const {
DCHECK(HasTypeLookupTableSection());
return Begin() + GetSectionHeader(VdexSection::kTypeLookupTableSection).section_offset;
}
MemMap mmap_;
DISALLOW_COPY_AND_ASSIGN(VdexFile);
};
} // namespace art
#endif // ART_RUNTIME_VDEX_FILE_H_