1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "elf_writer_quick.h"
18
19 #include <memory>
20 #include <openssl/sha.h>
21 #include <unordered_map>
22 #include <unordered_set>
23
24 #include <android-base/logging.h>
25
26 #include "base/casts.h"
27 #include "base/globals.h"
28 #include "base/leb128.h"
29 #include "base/utils.h"
30 #include "compiled_method.h"
31 #include "debug/elf_debug_writer.h"
32 #include "debug/method_debug_info.h"
33 #include "driver/compiler_options.h"
34 #include "elf/elf_builder.h"
35 #include "elf/elf_utils.h"
36 #include "stream/buffered_output_stream.h"
37 #include "stream/file_output_stream.h"
38 #include "thread-current-inl.h"
39 #include "thread_pool.h"
40
41 namespace art {
42 namespace linker {
43
44 class DebugInfoTask : public Task {
45 public:
DebugInfoTask(InstructionSet isa,const InstructionSetFeatures * features,uint64_t text_section_address,size_t text_section_size,uint64_t dex_section_address,size_t dex_section_size,const debug::DebugInfo & debug_info)46 DebugInfoTask(InstructionSet isa,
47 const InstructionSetFeatures* features,
48 uint64_t text_section_address,
49 size_t text_section_size,
50 uint64_t dex_section_address,
51 size_t dex_section_size,
52 const debug::DebugInfo& debug_info)
53 : isa_(isa),
54 instruction_set_features_(features),
55 text_section_address_(text_section_address),
56 text_section_size_(text_section_size),
57 dex_section_address_(dex_section_address),
58 dex_section_size_(dex_section_size),
59 debug_info_(debug_info) {
60 }
61
Run(Thread *)62 void Run(Thread*) override {
63 result_ = debug::MakeMiniDebugInfo(isa_,
64 instruction_set_features_,
65 text_section_address_,
66 text_section_size_,
67 dex_section_address_,
68 dex_section_size_,
69 debug_info_);
70 }
71
GetResult()72 std::vector<uint8_t>* GetResult() {
73 return &result_;
74 }
75
76 private:
77 InstructionSet isa_;
78 const InstructionSetFeatures* instruction_set_features_;
79 uint64_t text_section_address_;
80 size_t text_section_size_;
81 uint64_t dex_section_address_;
82 size_t dex_section_size_;
83 const debug::DebugInfo& debug_info_;
84 std::vector<uint8_t> result_;
85 };
86
87 template <typename ElfTypes>
88 class ElfWriterQuick final : public ElfWriter {
89 public:
90 ElfWriterQuick(const CompilerOptions& compiler_options,
91 File* elf_file);
92 ~ElfWriterQuick();
93
94 void Start() override;
95 void PrepareDynamicSection(size_t rodata_size,
96 size_t text_size,
97 size_t data_bimg_rel_ro_size,
98 size_t bss_size,
99 size_t bss_methods_offset,
100 size_t bss_roots_offset,
101 size_t dex_section_size) override;
102 void PrepareDebugInfo(const debug::DebugInfo& debug_info) override;
103 OutputStream* StartRoData() override;
104 void EndRoData(OutputStream* rodata) override;
105 OutputStream* StartText() override;
106 void EndText(OutputStream* text) override;
107 OutputStream* StartDataBimgRelRo() override;
108 void EndDataBimgRelRo(OutputStream* data_bimg_rel_ro) override;
109 void WriteDynamicSection() override;
110 void WriteDebugInfo(const debug::DebugInfo& debug_info) override;
111 bool StripDebugInfo() override;
112 bool End() override;
113
114 OutputStream* GetStream() override;
115
116 size_t GetLoadedSize() override;
117
118 static void EncodeOatPatches(const std::vector<uintptr_t>& locations,
119 std::vector<uint8_t>* buffer);
120
121 private:
122 const CompilerOptions& compiler_options_;
123 File* const elf_file_;
124 size_t rodata_size_;
125 size_t text_size_;
126 size_t data_bimg_rel_ro_size_;
127 size_t bss_size_;
128 size_t dex_section_size_;
129 std::unique_ptr<BufferedOutputStream> output_stream_;
130 std::unique_ptr<ElfBuilder<ElfTypes>> builder_;
131 std::unique_ptr<DebugInfoTask> debug_info_task_;
132 std::unique_ptr<ThreadPool> debug_info_thread_pool_;
133
134 void ComputeFileBuildId(uint8_t (*build_id)[ElfBuilder<ElfTypes>::kBuildIdLen]);
135
136 DISALLOW_IMPLICIT_CONSTRUCTORS(ElfWriterQuick);
137 };
138
CreateElfWriterQuick(const CompilerOptions & compiler_options,File * elf_file)139 std::unique_ptr<ElfWriter> CreateElfWriterQuick(const CompilerOptions& compiler_options,
140 File* elf_file) {
141 if (Is64BitInstructionSet(compiler_options.GetInstructionSet())) {
142 return std::make_unique<ElfWriterQuick<ElfTypes64>>(compiler_options, elf_file);
143 } else {
144 return std::make_unique<ElfWriterQuick<ElfTypes32>>(compiler_options, elf_file);
145 }
146 }
147
148 template <typename ElfTypes>
ElfWriterQuick(const CompilerOptions & compiler_options,File * elf_file)149 ElfWriterQuick<ElfTypes>::ElfWriterQuick(const CompilerOptions& compiler_options, File* elf_file)
150 : ElfWriter(),
151 compiler_options_(compiler_options),
152 elf_file_(elf_file),
153 rodata_size_(0u),
154 text_size_(0u),
155 data_bimg_rel_ro_size_(0u),
156 bss_size_(0u),
157 dex_section_size_(0u),
158 output_stream_(
159 std::make_unique<BufferedOutputStream>(std::make_unique<FileOutputStream>(elf_file))),
160 builder_(new ElfBuilder<ElfTypes>(compiler_options_.GetInstructionSet(),
161 output_stream_.get())) {}
162
163 template <typename ElfTypes>
~ElfWriterQuick()164 ElfWriterQuick<ElfTypes>::~ElfWriterQuick() {}
165
166 template <typename ElfTypes>
Start()167 void ElfWriterQuick<ElfTypes>::Start() {
168 builder_->Start();
169 if (compiler_options_.GetGenerateBuildId()) {
170 builder_->GetBuildId()->AllocateVirtualMemory(builder_->GetBuildId()->GetSize());
171 builder_->WriteBuildIdSection();
172 }
173 }
174
175 template <typename ElfTypes>
PrepareDynamicSection(size_t rodata_size,size_t text_size,size_t data_bimg_rel_ro_size,size_t bss_size,size_t bss_methods_offset,size_t bss_roots_offset,size_t dex_section_size)176 void ElfWriterQuick<ElfTypes>::PrepareDynamicSection(size_t rodata_size,
177 size_t text_size,
178 size_t data_bimg_rel_ro_size,
179 size_t bss_size,
180 size_t bss_methods_offset,
181 size_t bss_roots_offset,
182 size_t dex_section_size) {
183 DCHECK_EQ(rodata_size_, 0u);
184 rodata_size_ = rodata_size;
185 DCHECK_EQ(text_size_, 0u);
186 text_size_ = text_size;
187 DCHECK_EQ(data_bimg_rel_ro_size_, 0u);
188 data_bimg_rel_ro_size_ = data_bimg_rel_ro_size;
189 DCHECK_EQ(bss_size_, 0u);
190 bss_size_ = bss_size;
191 DCHECK_EQ(dex_section_size_, 0u);
192 dex_section_size_ = dex_section_size;
193 builder_->PrepareDynamicSection(elf_file_->GetPath(),
194 rodata_size_,
195 text_size_,
196 data_bimg_rel_ro_size_,
197 bss_size_,
198 bss_methods_offset,
199 bss_roots_offset,
200 dex_section_size);
201 }
202
203 template <typename ElfTypes>
StartRoData()204 OutputStream* ElfWriterQuick<ElfTypes>::StartRoData() {
205 auto* rodata = builder_->GetRoData();
206 rodata->Start();
207 return rodata;
208 }
209
210 template <typename ElfTypes>
EndRoData(OutputStream * rodata)211 void ElfWriterQuick<ElfTypes>::EndRoData(OutputStream* rodata) {
212 CHECK_EQ(builder_->GetRoData(), rodata);
213 builder_->GetRoData()->End();
214 }
215
216 template <typename ElfTypes>
StartText()217 OutputStream* ElfWriterQuick<ElfTypes>::StartText() {
218 auto* text = builder_->GetText();
219 text->Start();
220 return text;
221 }
222
223 template <typename ElfTypes>
EndText(OutputStream * text)224 void ElfWriterQuick<ElfTypes>::EndText(OutputStream* text) {
225 CHECK_EQ(builder_->GetText(), text);
226 builder_->GetText()->End();
227 }
228
229 template <typename ElfTypes>
StartDataBimgRelRo()230 OutputStream* ElfWriterQuick<ElfTypes>::StartDataBimgRelRo() {
231 auto* data_bimg_rel_ro = builder_->GetDataBimgRelRo();
232 data_bimg_rel_ro->Start();
233 return data_bimg_rel_ro;
234 }
235
236 template <typename ElfTypes>
EndDataBimgRelRo(OutputStream * data_bimg_rel_ro)237 void ElfWriterQuick<ElfTypes>::EndDataBimgRelRo(OutputStream* data_bimg_rel_ro) {
238 CHECK_EQ(builder_->GetDataBimgRelRo(), data_bimg_rel_ro);
239 builder_->GetDataBimgRelRo()->End();
240 }
241
242 template <typename ElfTypes>
WriteDynamicSection()243 void ElfWriterQuick<ElfTypes>::WriteDynamicSection() {
244 builder_->WriteDynamicSection();
245 }
246
247 template <typename ElfTypes>
PrepareDebugInfo(const debug::DebugInfo & debug_info)248 void ElfWriterQuick<ElfTypes>::PrepareDebugInfo(const debug::DebugInfo& debug_info) {
249 if (compiler_options_.GetGenerateMiniDebugInfo()) {
250 // Prepare the mini-debug-info in background while we do other I/O.
251 Thread* self = Thread::Current();
252 debug_info_task_ = std::make_unique<DebugInfoTask>(
253 builder_->GetIsa(),
254 compiler_options_.GetInstructionSetFeatures(),
255 builder_->GetText()->GetAddress(),
256 text_size_,
257 builder_->GetDex()->Exists() ? builder_->GetDex()->GetAddress() : 0,
258 dex_section_size_,
259 debug_info);
260 debug_info_thread_pool_ = std::make_unique<ThreadPool>("Mini-debug-info writer", 1);
261 debug_info_thread_pool_->AddTask(self, debug_info_task_.get());
262 debug_info_thread_pool_->StartWorkers(self);
263 }
264 }
265
266 template <typename ElfTypes>
WriteDebugInfo(const debug::DebugInfo & debug_info)267 void ElfWriterQuick<ElfTypes>::WriteDebugInfo(const debug::DebugInfo& debug_info) {
268 if (compiler_options_.GetGenerateMiniDebugInfo()) {
269 // Wait for the mini-debug-info generation to finish and write it to disk.
270 Thread* self = Thread::Current();
271 DCHECK(debug_info_thread_pool_ != nullptr);
272 debug_info_thread_pool_->Wait(self, true, false);
273 builder_->WriteSection(".gnu_debugdata", debug_info_task_->GetResult());
274 }
275 // The Strip method expects debug info to be last (mini-debug-info is not stripped).
276 if (!debug_info.Empty() && compiler_options_.GetGenerateDebugInfo()) {
277 // Generate all the debug information we can.
278 debug::WriteDebugInfo(builder_.get(), debug_info);
279 }
280 }
281
282 template <typename ElfTypes>
StripDebugInfo()283 bool ElfWriterQuick<ElfTypes>::StripDebugInfo() {
284 off_t file_size = builder_->Strip();
285 return elf_file_->SetLength(file_size) == 0;
286 }
287
288 template <typename ElfTypes>
End()289 bool ElfWriterQuick<ElfTypes>::End() {
290 builder_->End();
291 if (compiler_options_.GetGenerateBuildId()) {
292 uint8_t build_id[ElfBuilder<ElfTypes>::kBuildIdLen];
293 ComputeFileBuildId(&build_id);
294 builder_->WriteBuildId(build_id);
295 }
296 return builder_->Good();
297 }
298
299 template <typename ElfTypes>
ComputeFileBuildId(uint8_t (* build_id)[ElfBuilder<ElfTypes>::kBuildIdLen])300 void ElfWriterQuick<ElfTypes>::ComputeFileBuildId(
301 uint8_t (*build_id)[ElfBuilder<ElfTypes>::kBuildIdLen]) {
302 constexpr int kBufSize = 8192;
303 std::vector<char> buffer(kBufSize);
304 int64_t offset = 0;
305 SHA_CTX ctx;
306 SHA1_Init(&ctx);
307 while (true) {
308 int64_t bytes_read = elf_file_->Read(buffer.data(), kBufSize, offset);
309 CHECK_GE(bytes_read, 0);
310 if (bytes_read == 0) {
311 // End of file.
312 break;
313 }
314 SHA1_Update(&ctx, buffer.data(), bytes_read);
315 offset += bytes_read;
316 }
317 SHA1_Final(*build_id, &ctx);
318 }
319
320 template <typename ElfTypes>
GetStream()321 OutputStream* ElfWriterQuick<ElfTypes>::GetStream() {
322 return builder_->GetStream();
323 }
324
325 template <typename ElfTypes>
GetLoadedSize()326 size_t ElfWriterQuick<ElfTypes>::GetLoadedSize() {
327 return builder_->GetLoadedSize();
328 }
329
330 // Explicit instantiations
331 template class ElfWriterQuick<ElfTypes32>;
332 template class ElfWriterQuick<ElfTypes64>;
333
334 } // namespace linker
335 } // namespace art
336