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
22 #include <android-base/logging.h>
23
24 #include "base/casts.h"
25 #include "base/globals.h"
26 #include "base/leb128.h"
27 #include "base/utils.h"
28 #include "compiled_method.h"
29 #include "debug/elf_debug_writer.h"
30 #include "debug/method_debug_info.h"
31 #include "driver/compiler_options.h"
32 #include "elf/elf_builder.h"
33 #include "elf/elf_utils.h"
34 #include "stream/buffered_output_stream.h"
35 #include "stream/file_output_stream.h"
36 #include "thread-current-inl.h"
37 #include "thread_pool.h"
38
39 namespace art {
40 namespace linker {
41
42 class DebugInfoTask : public Task {
43 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)44 DebugInfoTask(InstructionSet isa,
45 const InstructionSetFeatures* features,
46 uint64_t text_section_address,
47 size_t text_section_size,
48 uint64_t dex_section_address,
49 size_t dex_section_size,
50 const debug::DebugInfo& debug_info)
51 : isa_(isa),
52 instruction_set_features_(features),
53 text_section_address_(text_section_address),
54 text_section_size_(text_section_size),
55 dex_section_address_(dex_section_address),
56 dex_section_size_(dex_section_size),
57 debug_info_(debug_info) {
58 }
59
Run(Thread *)60 void Run(Thread*) override {
61 result_ = debug::MakeMiniDebugInfo(isa_,
62 instruction_set_features_,
63 text_section_address_,
64 text_section_size_,
65 dex_section_address_,
66 dex_section_size_,
67 debug_info_);
68 }
69
GetResult()70 std::vector<uint8_t>* GetResult() {
71 return &result_;
72 }
73
74 private:
75 InstructionSet isa_;
76 const InstructionSetFeatures* instruction_set_features_;
77 uint64_t text_section_address_;
78 size_t text_section_size_;
79 uint64_t dex_section_address_;
80 size_t dex_section_size_;
81 const debug::DebugInfo& debug_info_;
82 std::vector<uint8_t> result_;
83 };
84
85 template <typename ElfTypes>
86 class ElfWriterQuick final : public ElfWriter {
87 public:
88 ElfWriterQuick(const CompilerOptions& compiler_options,
89 File* elf_file);
90 ~ElfWriterQuick();
91
92 void Start() override;
93 void PrepareDynamicSection(size_t rodata_size,
94 size_t text_size,
95 size_t data_bimg_rel_ro_size,
96 size_t bss_size,
97 size_t bss_methods_offset,
98 size_t bss_roots_offset,
99 size_t dex_section_size) override;
100 void PrepareDebugInfo(const debug::DebugInfo& debug_info) override;
101 OutputStream* StartRoData() override;
102 void EndRoData(OutputStream* rodata) override;
103 OutputStream* StartText() override;
104 void EndText(OutputStream* text) override;
105 OutputStream* StartDataBimgRelRo() override;
106 void EndDataBimgRelRo(OutputStream* data_bimg_rel_ro) override;
107 void WriteDynamicSection() override;
108 void WriteDebugInfo(const debug::DebugInfo& debug_info) override;
109 bool StripDebugInfo() override;
110 bool End() override;
111
112 OutputStream* GetStream() override;
113
114 size_t GetLoadedSize() override;
115
116 static void EncodeOatPatches(const std::vector<uintptr_t>& locations,
117 std::vector<uint8_t>* buffer);
118
119 private:
120 const CompilerOptions& compiler_options_;
121 File* const elf_file_;
122 size_t rodata_size_;
123 size_t text_size_;
124 size_t data_bimg_rel_ro_size_;
125 size_t bss_size_;
126 size_t dex_section_size_;
127 std::unique_ptr<BufferedOutputStream> output_stream_;
128 std::unique_ptr<ElfBuilder<ElfTypes>> builder_;
129 std::unique_ptr<DebugInfoTask> debug_info_task_;
130 std::unique_ptr<ThreadPool> debug_info_thread_pool_;
131
132 void ComputeFileBuildId(uint8_t (*build_id)[ElfBuilder<ElfTypes>::kBuildIdLen]);
133
134 DISALLOW_IMPLICIT_CONSTRUCTORS(ElfWriterQuick);
135 };
136
CreateElfWriterQuick(const CompilerOptions & compiler_options,File * elf_file)137 std::unique_ptr<ElfWriter> CreateElfWriterQuick(const CompilerOptions& compiler_options,
138 File* elf_file) {
139 if (Is64BitInstructionSet(compiler_options.GetInstructionSet())) {
140 return std::make_unique<ElfWriterQuick<ElfTypes64>>(compiler_options, elf_file);
141 } else {
142 return std::make_unique<ElfWriterQuick<ElfTypes32>>(compiler_options, elf_file);
143 }
144 }
145
146 template <typename ElfTypes>
ElfWriterQuick(const CompilerOptions & compiler_options,File * elf_file)147 ElfWriterQuick<ElfTypes>::ElfWriterQuick(const CompilerOptions& compiler_options, File* elf_file)
148 : ElfWriter(),
149 compiler_options_(compiler_options),
150 elf_file_(elf_file),
151 rodata_size_(0u),
152 text_size_(0u),
153 data_bimg_rel_ro_size_(0u),
154 bss_size_(0u),
155 dex_section_size_(0u),
156 output_stream_(
157 std::make_unique<BufferedOutputStream>(std::make_unique<FileOutputStream>(elf_file))),
158 builder_(new ElfBuilder<ElfTypes>(compiler_options_.GetInstructionSet(),
159 output_stream_.get())) {}
160
161 template <typename ElfTypes>
~ElfWriterQuick()162 ElfWriterQuick<ElfTypes>::~ElfWriterQuick() {}
163
164 template <typename ElfTypes>
Start()165 void ElfWriterQuick<ElfTypes>::Start() {
166 builder_->Start();
167 if (compiler_options_.GetGenerateBuildId()) {
168 builder_->GetBuildId()->AllocateVirtualMemory(builder_->GetBuildId()->GetSize());
169 builder_->WriteBuildIdSection();
170 }
171 }
172
173 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)174 void ElfWriterQuick<ElfTypes>::PrepareDynamicSection(size_t rodata_size,
175 size_t text_size,
176 size_t data_bimg_rel_ro_size,
177 size_t bss_size,
178 size_t bss_methods_offset,
179 size_t bss_roots_offset,
180 size_t dex_section_size) {
181 DCHECK_EQ(rodata_size_, 0u);
182 rodata_size_ = rodata_size;
183 DCHECK_EQ(text_size_, 0u);
184 text_size_ = text_size;
185 DCHECK_EQ(data_bimg_rel_ro_size_, 0u);
186 data_bimg_rel_ro_size_ = data_bimg_rel_ro_size;
187 DCHECK_EQ(bss_size_, 0u);
188 bss_size_ = bss_size;
189 DCHECK_EQ(dex_section_size_, 0u);
190 dex_section_size_ = dex_section_size;
191 builder_->PrepareDynamicSection(elf_file_->GetPath(),
192 rodata_size_,
193 text_size_,
194 data_bimg_rel_ro_size_,
195 bss_size_,
196 bss_methods_offset,
197 bss_roots_offset,
198 dex_section_size);
199 }
200
201 template <typename ElfTypes>
StartRoData()202 OutputStream* ElfWriterQuick<ElfTypes>::StartRoData() {
203 auto* rodata = builder_->GetRoData();
204 rodata->Start();
205 return rodata;
206 }
207
208 template <typename ElfTypes>
EndRoData(OutputStream * rodata)209 void ElfWriterQuick<ElfTypes>::EndRoData(OutputStream* rodata) {
210 CHECK_EQ(builder_->GetRoData(), rodata);
211 builder_->GetRoData()->End();
212 }
213
214 template <typename ElfTypes>
StartText()215 OutputStream* ElfWriterQuick<ElfTypes>::StartText() {
216 auto* text = builder_->GetText();
217 text->Start();
218 return text;
219 }
220
221 template <typename ElfTypes>
EndText(OutputStream * text)222 void ElfWriterQuick<ElfTypes>::EndText(OutputStream* text) {
223 CHECK_EQ(builder_->GetText(), text);
224 builder_->GetText()->End();
225 }
226
227 template <typename ElfTypes>
StartDataBimgRelRo()228 OutputStream* ElfWriterQuick<ElfTypes>::StartDataBimgRelRo() {
229 auto* data_bimg_rel_ro = builder_->GetDataBimgRelRo();
230 data_bimg_rel_ro->Start();
231 return data_bimg_rel_ro;
232 }
233
234 template <typename ElfTypes>
EndDataBimgRelRo(OutputStream * data_bimg_rel_ro)235 void ElfWriterQuick<ElfTypes>::EndDataBimgRelRo(OutputStream* data_bimg_rel_ro) {
236 CHECK_EQ(builder_->GetDataBimgRelRo(), data_bimg_rel_ro);
237 builder_->GetDataBimgRelRo()->End();
238 }
239
240 template <typename ElfTypes>
WriteDynamicSection()241 void ElfWriterQuick<ElfTypes>::WriteDynamicSection() {
242 builder_->WriteDynamicSection();
243 }
244
245 template <typename ElfTypes>
PrepareDebugInfo(const debug::DebugInfo & debug_info)246 void ElfWriterQuick<ElfTypes>::PrepareDebugInfo(const debug::DebugInfo& debug_info) {
247 if (compiler_options_.GetGenerateMiniDebugInfo()) {
248 // Prepare the mini-debug-info in background while we do other I/O.
249 Thread* self = Thread::Current();
250 debug_info_task_ = std::make_unique<DebugInfoTask>(
251 builder_->GetIsa(),
252 compiler_options_.GetInstructionSetFeatures(),
253 builder_->GetText()->GetAddress(),
254 text_size_,
255 builder_->GetDex()->Exists() ? builder_->GetDex()->GetAddress() : 0,
256 dex_section_size_,
257 debug_info);
258 debug_info_thread_pool_ = std::make_unique<ThreadPool>("Mini-debug-info writer", 1);
259 debug_info_thread_pool_->AddTask(self, debug_info_task_.get());
260 debug_info_thread_pool_->StartWorkers(self);
261 }
262 }
263
264 template <typename ElfTypes>
WriteDebugInfo(const debug::DebugInfo & debug_info)265 void ElfWriterQuick<ElfTypes>::WriteDebugInfo(const debug::DebugInfo& debug_info) {
266 if (compiler_options_.GetGenerateMiniDebugInfo()) {
267 // If mini-debug-info wasn't explicitly created so far, create it now (happens in tests).
268 if (debug_info_task_ == nullptr) {
269 PrepareDebugInfo(debug_info);
270 }
271 // Wait for the mini-debug-info generation to finish and write it to disk.
272 Thread* self = Thread::Current();
273 DCHECK(debug_info_thread_pool_ != nullptr);
274 debug_info_thread_pool_->Wait(self, true, false);
275 builder_->WriteSection(".gnu_debugdata", debug_info_task_->GetResult());
276 }
277 // The Strip method expects debug info to be last (mini-debug-info is not stripped).
278 if (!debug_info.Empty() && compiler_options_.GetGenerateDebugInfo()) {
279 // Generate all the debug information we can.
280 debug::WriteDebugInfo(builder_.get(), debug_info);
281 }
282 }
283
284 template <typename ElfTypes>
StripDebugInfo()285 bool ElfWriterQuick<ElfTypes>::StripDebugInfo() {
286 off_t file_size = builder_->Strip();
287 return elf_file_->SetLength(file_size) == 0;
288 }
289
290 template <typename ElfTypes>
End()291 bool ElfWriterQuick<ElfTypes>::End() {
292 builder_->End();
293 if (compiler_options_.GetGenerateBuildId()) {
294 uint8_t build_id[ElfBuilder<ElfTypes>::kBuildIdLen];
295 ComputeFileBuildId(&build_id);
296 builder_->WriteBuildId(build_id);
297 }
298 return builder_->Good();
299 }
300
301 template <typename ElfTypes>
ComputeFileBuildId(uint8_t (* build_id)[ElfBuilder<ElfTypes>::kBuildIdLen])302 void ElfWriterQuick<ElfTypes>::ComputeFileBuildId(
303 uint8_t (*build_id)[ElfBuilder<ElfTypes>::kBuildIdLen]) {
304 constexpr int kBufSize = 8192;
305 std::vector<char> buffer(kBufSize);
306 int64_t offset = 0;
307 SHA_CTX ctx;
308 SHA1_Init(&ctx);
309 while (true) {
310 int64_t bytes_read = elf_file_->Read(buffer.data(), kBufSize, offset);
311 CHECK_GE(bytes_read, 0);
312 if (bytes_read == 0) {
313 // End of file.
314 break;
315 }
316 SHA1_Update(&ctx, buffer.data(), bytes_read);
317 offset += bytes_read;
318 }
319 SHA1_Final(*build_id, &ctx);
320 }
321
322 template <typename ElfTypes>
GetStream()323 OutputStream* ElfWriterQuick<ElfTypes>::GetStream() {
324 return builder_->GetStream();
325 }
326
327 template <typename ElfTypes>
GetLoadedSize()328 size_t ElfWriterQuick<ElfTypes>::GetLoadedSize() {
329 return builder_->GetLoadedSize();
330 }
331
332 // Explicit instantiations
333 template class ElfWriterQuick<ElfTypes32>;
334 template class ElfWriterQuick<ElfTypes64>;
335
336 } // namespace linker
337 } // namespace art
338