1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/*
* 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.
*/
#include "vdex_file.h"
#include <sys/mman.h> // For the PROT_* and MAP_* constants.
#include <memory>
#include "base/logging.h"
#include "base/stl_util.h"
#include "base/unix_file/fd_file.h"
#include "dex_file.h"
#include "dex_to_dex_decompiler.h"
namespace art {
constexpr uint8_t VdexFile::Header::kVdexInvalidMagic[4];
constexpr uint8_t VdexFile::Header::kVdexMagic[4];
constexpr uint8_t VdexFile::Header::kVdexVersion[4];
bool VdexFile::Header::IsMagicValid() const {
return (memcmp(magic_, kVdexMagic, sizeof(kVdexMagic)) == 0);
}
bool VdexFile::Header::IsVersionValid() const {
return (memcmp(version_, kVdexVersion, sizeof(kVdexVersion)) == 0);
}
VdexFile::Header::Header(uint32_t number_of_dex_files,
uint32_t dex_size,
uint32_t verifier_deps_size,
uint32_t quickening_info_size)
: number_of_dex_files_(number_of_dex_files),
dex_size_(dex_size),
verifier_deps_size_(verifier_deps_size),
quickening_info_size_(quickening_info_size) {
memcpy(magic_, kVdexMagic, sizeof(kVdexMagic));
memcpy(version_, kVdexVersion, sizeof(kVdexVersion));
DCHECK(IsMagicValid());
DCHECK(IsVersionValid());
}
std::unique_ptr<VdexFile> VdexFile::Open(const std::string& vdex_filename,
bool writable,
bool low_4gb,
bool unquicken,
std::string* error_msg) {
if (!OS::FileExists(vdex_filename.c_str())) {
*error_msg = "File " + vdex_filename + " does not exist.";
return nullptr;
}
std::unique_ptr<File> vdex_file;
if (writable) {
vdex_file.reset(OS::OpenFileReadWrite(vdex_filename.c_str()));
} else {
vdex_file.reset(OS::OpenFileForReading(vdex_filename.c_str()));
}
if (vdex_file == nullptr) {
*error_msg = "Could not open file " + vdex_filename +
(writable ? " for read/write" : "for reading");
return nullptr;
}
int64_t vdex_length = vdex_file->GetLength();
if (vdex_length == -1) {
*error_msg = "Could not read the length of file " + vdex_filename;
return nullptr;
}
return Open(vdex_file->Fd(), vdex_length, vdex_filename, writable, low_4gb, unquicken, error_msg);
}
std::unique_ptr<VdexFile> 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) {
std::unique_ptr<MemMap> mmap(MemMap::MapFile(
vdex_length,
(writable || unquicken) ? PROT_READ | PROT_WRITE : PROT_READ,
unquicken ? MAP_PRIVATE : MAP_SHARED,
file_fd,
0 /* start offset */,
low_4gb,
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(new VdexFile(mmap.release()));
if (!vdex->IsValid()) {
*error_msg = "Vdex file is not valid";
return nullptr;
}
if (unquicken) {
std::vector<std::unique_ptr<const DexFile>> unique_ptr_dex_files;
if (!vdex->OpenAllDexFiles(&unique_ptr_dex_files, error_msg)) {
return nullptr;
}
Unquicken(MakeNonOwningPointerVector(unique_ptr_dex_files), vdex->GetQuickeningInfo());
// Update the quickening info size to pretend there isn't any.
reinterpret_cast<Header*>(vdex->mmap_->Begin())->quickening_info_size_ = 0;
}
*error_msg = "Success";
return vdex;
}
const uint8_t* VdexFile::GetNextDexFileData(const uint8_t* cursor) const {
DCHECK(cursor == nullptr || (cursor > Begin() && cursor <= End()));
if (cursor == nullptr) {
// Beginning of the iteration, return the first dex file if there is one.
return HasDexSection() ? DexBegin() : nullptr;
} else {
// Fetch the next dex file. Return null if there is none.
const uint8_t* data = cursor + reinterpret_cast<const DexFile::Header*>(cursor)->file_size_;
return (data == DexEnd()) ? nullptr : data;
}
}
bool VdexFile::OpenAllDexFiles(std::vector<std::unique_ptr<const DexFile>>* dex_files,
std::string* error_msg) {
size_t i = 0;
for (const uint8_t* dex_file_start = GetNextDexFileData(nullptr);
dex_file_start != nullptr;
dex_file_start = GetNextDexFileData(dex_file_start), ++i) {
size_t size = reinterpret_cast<const DexFile::Header*>(dex_file_start)->file_size_;
// TODO: Supply the location information for a vdex file.
static constexpr char kVdexLocation[] = "";
std::string location = DexFile::GetMultiDexLocation(i, kVdexLocation);
std::unique_ptr<const DexFile> dex(DexFile::Open(dex_file_start,
size,
location,
GetLocationChecksum(i),
nullptr /*oat_dex_file*/,
false /*verify*/,
false /*verify_checksum*/,
error_msg));
if (dex == nullptr) {
return false;
}
dex_files->push_back(std::move(dex));
}
return true;
}
void VdexFile::Unquicken(const std::vector<const DexFile*>& dex_files,
const ArrayRef<const uint8_t>& quickening_info) {
if (quickening_info.size() == 0) {
// If there is no quickening info, we bail early, as the code below expects at
// least the size of quickening data for each method that has a code item.
return;
}
const uint8_t* quickening_info_ptr = quickening_info.data();
const uint8_t* const quickening_info_end = quickening_info.data() + quickening_info.size();
for (const DexFile* dex_file : dex_files) {
for (uint32_t i = 0; i < dex_file->NumClassDefs(); ++i) {
const DexFile::ClassDef& class_def = dex_file->GetClassDef(i);
const uint8_t* class_data = dex_file->GetClassData(class_def);
if (class_data == nullptr) {
continue;
}
ClassDataItemIterator it(*dex_file, class_data);
// Skip fields
while (it.HasNextStaticField()) {
it.Next();
}
while (it.HasNextInstanceField()) {
it.Next();
}
while (it.HasNextDirectMethod()) {
const DexFile::CodeItem* code_item = it.GetMethodCodeItem();
if (code_item != nullptr) {
uint32_t quickening_size = *reinterpret_cast<const uint32_t*>(quickening_info_ptr);
quickening_info_ptr += sizeof(uint32_t);
optimizer::ArtDecompileDEX(*code_item,
ArrayRef<const uint8_t>(quickening_info_ptr, quickening_size),
/* decompile_return_instruction */ false);
quickening_info_ptr += quickening_size;
}
it.Next();
}
while (it.HasNextVirtualMethod()) {
const DexFile::CodeItem* code_item = it.GetMethodCodeItem();
if (code_item != nullptr) {
uint32_t quickening_size = *reinterpret_cast<const uint32_t*>(quickening_info_ptr);
quickening_info_ptr += sizeof(uint32_t);
optimizer::ArtDecompileDEX(*code_item,
ArrayRef<const uint8_t>(quickening_info_ptr, quickening_size),
/* decompile_return_instruction */ false);
quickening_info_ptr += quickening_size;
}
it.Next();
}
DCHECK(!it.HasNext());
}
}
if (quickening_info_ptr != quickening_info_end) {
LOG(FATAL) << "Failed to use all quickening info";
}
}
} // namespace art
|