Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 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.h" |
| 18 | |
| 19 | #include "base/unix_file/fd_file.h" |
Ian Rogers | 1212a02 | 2013-03-04 10:48:41 -0800 | [diff] [blame^] | 20 | #include "compiler/driver/compiler_driver.h" |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 21 | #include "elf_file.h" |
| 22 | #include "oat.h" |
| 23 | #include "oat_file.h" |
| 24 | |
| 25 | #include <llvm/Support/TargetSelect.h> |
| 26 | |
| 27 | #include <mcld/Environment.h> |
| 28 | #include <mcld/IRBuilder.h> |
| 29 | #include <mcld/Linker.h> |
| 30 | #include <mcld/LinkerConfig.h> |
Brian Carlstrom | 818d98e | 2013-02-10 21:38:12 -0800 | [diff] [blame] | 31 | #include <mcld/MC/ZOption.h> |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 32 | #include <mcld/Module.h> |
| 33 | #include <mcld/Support/Path.h> |
| 34 | #include <mcld/Support/TargetSelect.h> |
| 35 | |
| 36 | namespace art { |
| 37 | |
Ian Rogers | 1212a02 | 2013-03-04 10:48:41 -0800 | [diff] [blame^] | 38 | bool ElfWriter::Create(File* file, std::vector<uint8_t>& oat_contents, const CompilerDriver& compiler) { |
| 39 | ElfWriter elf_writer(&compiler); |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 40 | return elf_writer.Write(oat_contents, file); |
| 41 | } |
| 42 | |
Ian Rogers | 1212a02 | 2013-03-04 10:48:41 -0800 | [diff] [blame^] | 43 | ElfWriter::ElfWriter(const CompilerDriver* driver) : compiler_driver_(driver) {} |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 44 | |
| 45 | ElfWriter::~ElfWriter() {} |
| 46 | |
| 47 | static void InitializeLLVM() { |
| 48 | // TODO: this is lifted from art's compiler_llvm.cc, should be factored out |
| 49 | #if defined(ART_TARGET) |
| 50 | llvm::InitializeNativeTarget(); |
| 51 | // TODO: odd that there is no InitializeNativeTargetMC? |
| 52 | #else |
| 53 | llvm::InitializeAllTargets(); |
| 54 | llvm::InitializeAllTargetMCs(); |
| 55 | #endif |
| 56 | } |
| 57 | |
| 58 | bool ElfWriter::Write(std::vector<uint8_t>& oat_contents, File* elf_file) { |
| 59 | |
| 60 | std::string target_triple; |
| 61 | std::string target_cpu; |
| 62 | std::string target_attr; |
Ian Rogers | 1212a02 | 2013-03-04 10:48:41 -0800 | [diff] [blame^] | 63 | CompilerDriver::InstructionSetToLLVMTarget(compiler_driver_->GetInstructionSet(), |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 64 | target_triple, |
| 65 | target_cpu, |
| 66 | target_attr); |
| 67 | |
| 68 | { |
| 69 | // Based on mclinker's llvm-mcld.cpp main() and LinkerTest |
| 70 | // |
| 71 | // TODO: LinkerTest uses mcld::Initialize(), but it does an |
| 72 | // llvm::InitializeAllTargets, which we don't want. Basically we |
| 73 | // want mcld::InitializeNative, but it doesn't exist yet, so we |
| 74 | // inline the minimal we need here. |
| 75 | InitializeLLVM(); |
| 76 | mcld::InitializeAllTargets(); |
| 77 | mcld::InitializeAllLinkers(); |
| 78 | mcld::InitializeAllEmulations(); |
| 79 | mcld::InitializeAllDiagnostics(); |
| 80 | |
| 81 | UniquePtr<mcld::LinkerConfig> linker_config(new mcld::LinkerConfig(target_triple)); |
| 82 | CHECK(linker_config.get() != NULL); |
| 83 | linker_config->setCodeGenType(mcld::LinkerConfig::DynObj); |
Ian Rogers | 1212a02 | 2013-03-04 10:48:41 -0800 | [diff] [blame^] | 84 | if (compiler_driver_->GetInstructionSet() == kMips) { |
Brian Carlstrom | 818d98e | 2013-02-10 21:38:12 -0800 | [diff] [blame] | 85 | // MCLinker defaults MIPS section alignment to 0x10000, not 0x1000 |
| 86 | mcld::ZOption z_option; |
| 87 | z_option.setKind(mcld::ZOption::MaxPageSize); |
| 88 | z_option.setPageSize(kPageSize); |
| 89 | linker_config->options().addZOption(z_option); |
| 90 | } |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 91 | linker_config->options().setSOName(elf_file->GetPath()); |
| 92 | // TODO: Wire up mcld DiagnosticEngine to LOG? |
| 93 | if (false) { |
| 94 | // enables some tracing of input file processing |
| 95 | linker_config->options().setTrace(true); |
| 96 | } |
| 97 | |
| 98 | // Based on alone::Linker::config |
| 99 | UniquePtr<mcld::Module> module(new mcld::Module(linker_config->options().soname())); |
| 100 | CHECK(module.get() != NULL); |
| 101 | UniquePtr<mcld::IRBuilder> ir_builder(new mcld::IRBuilder(*module.get(), *linker_config.get())); |
| 102 | CHECK(ir_builder.get() != NULL); |
| 103 | UniquePtr<mcld::Linker> linker(new mcld::Linker()); |
| 104 | CHECK(linker.get() != NULL); |
| 105 | linker->config(*linker_config.get()); |
| 106 | |
| 107 | |
| 108 | // Add an artificial memory input. Based on LinkerTest. |
| 109 | UniquePtr<OatFile> oat_file(OatFile::Open(oat_contents, elf_file->GetPath())); |
| 110 | CHECK(oat_file.get() != NULL) << elf_file->GetPath(); |
| 111 | |
| 112 | const char* oat_data_start = reinterpret_cast<const char*>(&oat_file->GetOatHeader()); |
| 113 | const size_t oat_data_length = oat_file->GetOatHeader().GetExecutableOffset(); |
| 114 | const char* oat_code_start = oat_data_start + oat_data_length; |
| 115 | const size_t oat_code_length = oat_file->Size() - oat_data_length; |
| 116 | |
| 117 | // TODO: ownership of input? |
| 118 | mcld::Input* input = ir_builder->CreateInput("oat contents", |
| 119 | mcld::sys::fs::Path("oat contents path"), |
| 120 | mcld::Input::Object); |
| 121 | CHECK(input != NULL); |
| 122 | |
| 123 | // TODO: ownership of null_section? |
| 124 | mcld::LDSection* null_section = ir_builder->CreateELFHeader(*input, |
| 125 | "", |
| 126 | mcld::LDFileFormat::Null, |
| 127 | llvm::ELF::SHT_NULL, |
| 128 | 0); |
| 129 | CHECK(null_section != NULL); |
| 130 | |
| 131 | // TODO: we should split readonly data from readonly executable |
| 132 | // code like .oat does. We need to control section layout with |
| 133 | // linker script like functionality to guarantee references |
| 134 | // between sections maintain relative position which isn't |
| 135 | // possible right now with the mclinker APIs. |
| 136 | CHECK(oat_code_start); |
| 137 | |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 138 | // we need to ensure that oatdata is page aligned so when we |
| 139 | // fixup the segment load addresses, they remain page aligned. |
Brian Carlstrom | 818d98e | 2013-02-10 21:38:12 -0800 | [diff] [blame] | 140 | uint32_t alignment = kPageSize; |
| 141 | |
| 142 | // TODO: ownership of text_section? |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 143 | mcld::LDSection* text_section = ir_builder->CreateELFHeader(*input, |
| 144 | ".text", |
| 145 | llvm::ELF::SHT_PROGBITS, |
| 146 | llvm::ELF::SHF_EXECINSTR |
| 147 | | llvm::ELF::SHF_ALLOC, |
Brian Carlstrom | 818d98e | 2013-02-10 21:38:12 -0800 | [diff] [blame] | 148 | alignment); |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 149 | CHECK(text_section != NULL); |
| 150 | |
| 151 | mcld::SectionData* text_section_data = ir_builder->CreateSectionData(*text_section); |
| 152 | CHECK(text_section_data != NULL); |
| 153 | |
| 154 | // TODO: why does IRBuilder::CreateRegion take a non-const pointer? |
| 155 | mcld::Fragment* text_fragment = ir_builder->CreateRegion(const_cast<char*>(oat_data_start), |
| 156 | oat_file->Size()); |
| 157 | CHECK(text_fragment != NULL); |
| 158 | ir_builder->AppendFragment(*text_fragment, *text_section_data); |
| 159 | |
| 160 | ir_builder->AddSymbol(*input, |
| 161 | "oatdata", |
| 162 | mcld::ResolveInfo::Object, |
| 163 | mcld::ResolveInfo::Define, |
| 164 | mcld::ResolveInfo::Global, |
| 165 | oat_data_length, // size |
| 166 | 0, // offset |
| 167 | text_section); |
| 168 | |
| 169 | ir_builder->AddSymbol(*input, |
| 170 | "oatexec", |
Ian Rogers | e9de2dd | 2013-01-31 11:11:16 -0800 | [diff] [blame] | 171 | mcld::ResolveInfo::Function, |
Brian Carlstrom | 700c8d3 | 2012-11-05 10:42:02 -0800 | [diff] [blame] | 172 | mcld::ResolveInfo::Define, |
| 173 | mcld::ResolveInfo::Global, |
| 174 | oat_code_length, // size |
| 175 | oat_data_length, // offset |
| 176 | text_section); |
| 177 | |
| 178 | ir_builder->AddSymbol(*input, |
| 179 | "oatlastword", |
| 180 | mcld::ResolveInfo::Object, |
| 181 | mcld::ResolveInfo::Define, |
| 182 | mcld::ResolveInfo::Global, |
| 183 | 0, // size |
| 184 | // subtract a word so symbol is within section |
| 185 | (oat_data_length + oat_code_length) - sizeof(uint32_t), // offset |
| 186 | text_section); |
| 187 | |
| 188 | // link inputs |
| 189 | if (!linker->link(*module.get(), *ir_builder.get())) { |
| 190 | LOG(ERROR) << "problem linking " << elf_file->GetPath(); |
| 191 | return false; |
| 192 | } |
| 193 | |
| 194 | // emited linked output |
| 195 | if (!linker->emit(elf_file->Fd())) { |
| 196 | LOG(ERROR) << "problem emitting " << elf_file->GetPath(); |
| 197 | return false; |
| 198 | } |
| 199 | // TODO: mcld::Linker::emit closed the file descriptor. It probably shouldn't. |
| 200 | // For now, close our File to match. |
| 201 | elf_file->Close(); |
| 202 | mcld::Finalize(); |
| 203 | } |
| 204 | LOG(INFO) << "ELF file written successfully: " << elf_file->GetPath(); |
| 205 | return true; |
| 206 | } |
| 207 | |
| 208 | bool ElfWriter::Fixup(File* file, uintptr_t oat_data_begin) { |
| 209 | UniquePtr<ElfFile> elf_file(ElfFile::Open(file, true, false)); |
| 210 | CHECK(elf_file.get() != NULL); |
| 211 | |
| 212 | // Lookup "oatdata" symbol address. |
| 213 | llvm::ELF::Elf32_Addr oatdata_address = elf_file->FindSymbolAddress(llvm::ELF::SHT_DYNSYM, |
| 214 | "oatdata"); |
| 215 | CHECK_NE(0U, oatdata_address); |
| 216 | llvm::ELF::Elf32_Off base_address = oat_data_begin - oatdata_address; |
| 217 | |
| 218 | if (!FixupDynamic(*elf_file.get(), base_address)) { |
| 219 | LOG(WARNING) << "Failed fo fixup .dynamic in " << file->GetPath(); |
| 220 | return false; |
| 221 | } |
| 222 | if (!FixupSectionHeaders(*elf_file.get(), base_address)) { |
| 223 | LOG(WARNING) << "Failed fo fixup section headers in " << file->GetPath(); |
| 224 | return false; |
| 225 | } |
| 226 | if (!FixupProgramHeaders(*elf_file.get(), base_address)) { |
| 227 | LOG(WARNING) << "Failed fo fixup program headers in " << file->GetPath(); |
| 228 | return false; |
| 229 | } |
| 230 | if (!FixupSymbols(*elf_file.get(), base_address, true)) { |
| 231 | LOG(WARNING) << "Failed fo fixup .dynsym in " << file->GetPath(); |
| 232 | return false; |
| 233 | } |
| 234 | if (!FixupSymbols(*elf_file.get(), base_address, false)) { |
| 235 | LOG(WARNING) << "Failed fo fixup .symtab in " << file->GetPath(); |
| 236 | return false; |
| 237 | } |
| 238 | return true; |
| 239 | } |
| 240 | |
| 241 | bool ElfWriter::FixupDynamic(ElfFile& elf_file, uintptr_t base_address) { |
| 242 | // TODO: C++0x auto. |
| 243 | for (llvm::ELF::Elf32_Word i = 0; i < elf_file.GetDynamicNum(); i++) { |
| 244 | llvm::ELF::Elf32_Dyn& elf_dyn = elf_file.GetDynamic(i); |
| 245 | bool elf_dyn_needs_fixup = false; |
| 246 | // case 1: if Elf32_Dyn.d_tag implies Elf32_Dyn.d_un contains an address in d_ptr |
| 247 | switch (elf_dyn.d_tag) { |
| 248 | case llvm::ELF::DT_PLTGOT: |
| 249 | case llvm::ELF::DT_HASH: |
| 250 | case llvm::ELF::DT_STRTAB: |
| 251 | case llvm::ELF::DT_SYMTAB: |
| 252 | case llvm::ELF::DT_RELA: |
| 253 | case llvm::ELF::DT_INIT: |
| 254 | case llvm::ELF::DT_FINI: |
| 255 | case llvm::ELF::DT_REL: |
| 256 | case llvm::ELF::DT_DEBUG: |
| 257 | case llvm::ELF::DT_JMPREL: { |
| 258 | elf_dyn_needs_fixup = true; |
| 259 | break; |
| 260 | } |
| 261 | default: { |
| 262 | // case 2: if d_tag is even and greater than > DT_ENCODING |
| 263 | if ((elf_dyn.d_tag > llvm::ELF::DT_ENCODING) && ((elf_dyn.d_tag % 2) == 0)) { |
| 264 | elf_dyn_needs_fixup = true; |
| 265 | } |
| 266 | break; |
| 267 | } |
| 268 | } |
| 269 | if (elf_dyn_needs_fixup) { |
| 270 | uint32_t d_ptr = elf_dyn.d_un.d_ptr; |
| 271 | d_ptr += base_address; |
| 272 | elf_dyn.d_un.d_ptr = d_ptr; |
| 273 | } |
| 274 | } |
| 275 | return true; |
| 276 | } |
| 277 | |
| 278 | bool ElfWriter::FixupSectionHeaders(ElfFile& elf_file, uintptr_t base_address) { |
| 279 | for (llvm::ELF::Elf32_Word i = 0; i < elf_file.GetSectionHeaderNum(); i++) { |
| 280 | llvm::ELF::Elf32_Shdr& sh = elf_file.GetSectionHeader(i); |
| 281 | // 0 implies that the section will not exist in the memory of the process |
| 282 | if (sh.sh_addr == 0) { |
| 283 | continue; |
| 284 | } |
| 285 | sh.sh_addr += base_address; |
| 286 | } |
| 287 | return true; |
| 288 | } |
| 289 | |
| 290 | bool ElfWriter::FixupProgramHeaders(ElfFile& elf_file, uintptr_t base_address) { |
| 291 | // TODO: ELFObjectFile doesn't have give to Elf32_Phdr, so we do that ourselves for now. |
| 292 | for (llvm::ELF::Elf32_Word i = 0; i < elf_file.GetProgramHeaderNum(); i++) { |
| 293 | llvm::ELF::Elf32_Phdr& ph = elf_file.GetProgramHeader(i); |
| 294 | CHECK_EQ(ph.p_vaddr, ph.p_paddr) << elf_file.GetFile().GetPath() << " i=" << i; |
| 295 | CHECK((ph.p_align == 0) || (0 == ((ph.p_vaddr - ph.p_offset) & (ph.p_align - 1)))); |
| 296 | ph.p_vaddr += base_address; |
| 297 | ph.p_paddr += base_address; |
| 298 | CHECK((ph.p_align == 0) || (0 == ((ph.p_vaddr - ph.p_offset) & (ph.p_align - 1)))); |
| 299 | } |
| 300 | return true; |
| 301 | } |
| 302 | |
| 303 | bool ElfWriter::FixupSymbols(ElfFile& elf_file, uintptr_t base_address, bool dynamic) { |
| 304 | llvm::ELF::Elf32_Word section_type = dynamic ? llvm::ELF::SHT_DYNSYM : llvm::ELF::SHT_SYMTAB; |
| 305 | // TODO: Unfortunate ELFObjectFile has protected symbol access, so use ElfFile |
| 306 | llvm::ELF::Elf32_Shdr* symbol_section = elf_file.FindSectionByType(section_type); |
| 307 | CHECK(symbol_section != NULL) << elf_file.GetFile().GetPath(); |
| 308 | for (uint32_t i = 0; i < elf_file.GetSymbolNum(*symbol_section); i++) { |
| 309 | llvm::ELF::Elf32_Sym& symbol = elf_file.GetSymbol(section_type, i); |
| 310 | if (symbol.st_value != 0) { |
| 311 | symbol.st_value += base_address; |
| 312 | } |
| 313 | } |
| 314 | return true; |
| 315 | } |
| 316 | |
| 317 | void ElfWriter::GetOatElfInformation(File* file, |
| 318 | size_t& oat_loaded_size, |
| 319 | size_t& oat_data_offset) { |
| 320 | UniquePtr<ElfFile> elf_file(ElfFile::Open(file, false, false)); |
| 321 | CHECK(elf_file.get() != NULL); |
| 322 | |
| 323 | oat_loaded_size = elf_file->GetLoadedSize(); |
| 324 | CHECK_NE(0U, oat_loaded_size); |
| 325 | oat_data_offset = elf_file->FindSymbolAddress(llvm::ELF::SHT_DYNSYM, "oatdata"); |
| 326 | CHECK_NE(0U, oat_data_offset); |
| 327 | } |
| 328 | |
| 329 | } // namespace art |