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 "base/logging.h" 20 #include "base/unix_file/fd_file.h" 21 #include "buffered_output_stream.h" 22 #include "driver/compiler_driver.h" 23 #include "file_output_stream.h" 24 #include "globals.h" 25 #include "oat.h" 26 #include "oat_writer.h" 27 #include "utils.h" 28 29 namespace art { 30 31 ElfWriterQuick::ElfWriterQuick(const CompilerDriver& driver, File* elf_file) 32 : ElfWriter(driver, elf_file) {} 33 34 ElfWriterQuick::~ElfWriterQuick() {} 35 36 bool ElfWriterQuick::Create(File* elf_file, 37 OatWriter& oat_writer, 38 const std::vector<const DexFile*>& dex_files, 39 const std::string& android_root, 40 bool is_host, 41 const CompilerDriver& driver) { 42 ElfWriterQuick elf_writer(driver, elf_file); 43 return elf_writer.Write(oat_writer, dex_files, android_root, is_host); 44 } 45 46 bool ElfWriterQuick::Write(OatWriter& oat_writer, 47 const std::vector<const DexFile*>& dex_files_unused, 48 const std::string& android_root_unused, 49 bool is_host_unused) { 50 const bool debug = false; 51 // +-------------------------+ 52 // | Elf32_Ehdr | 53 // +-------------------------+ 54 // | Elf32_Phdr PHDR | 55 // | Elf32_Phdr LOAD R | .dynsym .dynstr .hash .rodata 56 // | Elf32_Phdr LOAD R X | .text 57 // | Elf32_Phdr LOAD RW | .dynamic 58 // | Elf32_Phdr DYNAMIC | .dynamic 59 // +-------------------------+ 60 // | .dynsym | 61 // | Elf32_Sym STN_UNDEF | 62 // | Elf32_Sym oatdata | 63 // | Elf32_Sym oatexec | 64 // | Elf32_Sym oatlastword | 65 // +-------------------------+ 66 // | .dynstr | 67 // | \0 | 68 // | oatdata\0 | 69 // | oatexec\0 | 70 // | oatlastword\0 | 71 // | boot.oat\0 | 72 // +-------------------------+ 73 // | .hash | 74 // | Elf32_Word nbucket = 1 | 75 // | Elf32_Word nchain = 3 | 76 // | Elf32_Word bucket[0] = 0| 77 // | Elf32_Word chain[0] = 1| 78 // | Elf32_Word chain[1] = 2| 79 // | Elf32_Word chain[2] = 3| 80 // +-------------------------+ 81 // | .rodata | 82 // | oatdata..oatexec-4 | 83 // +-------------------------+ 84 // | .text | 85 // | oatexec..oatlastword | 86 // +-------------------------+ 87 // | .dynamic | 88 // | Elf32_Dyn DT_SONAME | 89 // | Elf32_Dyn DT_HASH | 90 // | Elf32_Dyn DT_SYMTAB | 91 // | Elf32_Dyn DT_SYMENT | 92 // | Elf32_Dyn DT_STRTAB | 93 // | Elf32_Dyn DT_STRSZ | 94 // | Elf32_Dyn DT_NULL | 95 // +-------------------------+ 96 // | .shstrtab | 97 // | \0 | 98 // | .dynamic\0 | 99 // | .dynsym\0 | 100 // | .dynstr\0 | 101 // | .hash\0 | 102 // | .rodata\0 | 103 // | .text\0 | 104 // | .shstrtab\0 | 105 // +-------------------------+ 106 // | Elf32_Shdr NULL | 107 // | Elf32_Shdr .dynsym | 108 // | Elf32_Shdr .dynstr | 109 // | Elf32_Shdr .hash | 110 // | Elf32_Shdr .text | 111 // | Elf32_Shdr .rodata | 112 // | Elf32_Shdr .dynamic | 113 // | Elf32_Shdr .shstrtab | 114 // +-------------------------+ 115 116 // phase 1: computing offsets 117 uint32_t expected_offset = 0; 118 119 // Elf32_Ehdr 120 expected_offset += sizeof(llvm::ELF::Elf32_Ehdr); 121 122 // PHDR 123 uint32_t phdr_alignment = sizeof(llvm::ELF::Elf32_Word); 124 uint32_t phdr_offset = expected_offset; 125 const uint8_t PH_PHDR = 0; 126 const uint8_t PH_LOAD_R__ = 1; 127 const uint8_t PH_LOAD_R_X = 2; 128 const uint8_t PH_LOAD_RW_ = 3; 129 const uint8_t PH_DYNAMIC = 4; 130 const uint8_t PH_NUM = 5; 131 uint32_t phdr_size = sizeof(llvm::ELF::Elf32_Phdr) * PH_NUM; 132 expected_offset += phdr_size; 133 if (debug) { 134 LOG(INFO) << "phdr_offset=" << phdr_offset << std::hex << " " << phdr_offset; 135 LOG(INFO) << "phdr_size=" << phdr_size << std::hex << " " << phdr_size; 136 } 137 138 // .dynsym 139 uint32_t dynsym_alignment = sizeof(llvm::ELF::Elf32_Word); 140 uint32_t dynsym_offset = expected_offset = RoundUp(expected_offset, dynsym_alignment); 141 const uint8_t SYM_UNDEF = 0; // aka STN_UNDEF 142 const uint8_t SYM_OATDATA = 1; 143 const uint8_t SYM_OATEXEC = 2; 144 const uint8_t SYM_OATLASTWORD = 3; 145 const uint8_t SYM_NUM = 4; 146 uint32_t dynsym_size = sizeof(llvm::ELF::Elf32_Sym) * SYM_NUM; 147 expected_offset += dynsym_size; 148 if (debug) { 149 LOG(INFO) << "dynsym_offset=" << dynsym_offset << std::hex << " " << dynsym_offset; 150 LOG(INFO) << "dynsym_size=" << dynsym_size << std::hex << " " << dynsym_size; 151 } 152 153 // .dynstr 154 uint32_t dynstr_alignment = 1; 155 uint32_t dynstr_offset = expected_offset = RoundUp(expected_offset, dynstr_alignment); 156 std::string dynstr; 157 dynstr += '\0'; 158 uint32_t dynstr_oatdata_offset = dynstr.size(); 159 dynstr += "oatdata"; 160 dynstr += '\0'; 161 uint32_t dynstr_oatexec_offset = dynstr.size(); 162 dynstr += "oatexec"; 163 dynstr += '\0'; 164 uint32_t dynstr_oatlastword_offset = dynstr.size(); 165 dynstr += "oatlastword"; 166 dynstr += '\0'; 167 uint32_t dynstr_soname_offset = dynstr.size(); 168 std::string file_name(elf_file_->GetPath()); 169 size_t directory_separator_pos = file_name.rfind('/'); 170 if (directory_separator_pos != std::string::npos) { 171 file_name = file_name.substr(directory_separator_pos + 1); 172 } 173 dynstr += file_name; 174 dynstr += '\0'; 175 uint32_t dynstr_size = dynstr.size(); 176 expected_offset += dynstr_size; 177 if (debug) { 178 LOG(INFO) << "dynstr_offset=" << dynstr_offset << std::hex << " " << dynstr_offset; 179 LOG(INFO) << "dynstr_size=" << dynstr_size << std::hex << " " << dynstr_size; 180 } 181 182 // .hash 183 uint32_t hash_alignment = sizeof(llvm::ELF::Elf32_Word); // Even for 64-bit 184 uint32_t hash_offset = expected_offset = RoundUp(expected_offset, hash_alignment); 185 const uint8_t HASH_NBUCKET = 0; 186 const uint8_t HASH_NCHAIN = 1; 187 const uint8_t HASH_BUCKET0 = 2; 188 const uint8_t HASH_NUM = HASH_BUCKET0 + 1 + SYM_NUM; 189 uint32_t hash_size = sizeof(llvm::ELF::Elf32_Word) * HASH_NUM; 190 expected_offset += hash_size; 191 if (debug) { 192 LOG(INFO) << "hash_offset=" << hash_offset << std::hex << " " << hash_offset; 193 LOG(INFO) << "hash_size=" << hash_size << std::hex << " " << hash_size; 194 } 195 196 // .rodata 197 uint32_t oat_data_alignment = kPageSize; 198 uint32_t oat_data_offset = expected_offset = RoundUp(expected_offset, oat_data_alignment); 199 const OatHeader& oat_header = oat_writer.GetOatHeader(); 200 CHECK(oat_header.IsValid()); 201 uint32_t oat_data_size = oat_header.GetExecutableOffset(); 202 expected_offset += oat_data_size; 203 if (debug) { 204 LOG(INFO) << "oat_data_offset=" << oat_data_offset << std::hex << " " << oat_data_offset; 205 LOG(INFO) << "oat_data_size=" << oat_data_size << std::hex << " " << oat_data_size; 206 } 207 208 // .text 209 uint32_t oat_exec_alignment = kPageSize; 210 CHECK_ALIGNED(expected_offset, kPageSize); 211 uint32_t oat_exec_offset = expected_offset = RoundUp(expected_offset, oat_exec_alignment); 212 uint32_t oat_exec_size = oat_writer.GetSize() - oat_data_size; 213 expected_offset += oat_exec_size; 214 CHECK_EQ(oat_data_offset + oat_writer.GetSize(), expected_offset); 215 if (debug) { 216 LOG(INFO) << "oat_exec_offset=" << oat_exec_offset << std::hex << " " << oat_exec_offset; 217 LOG(INFO) << "oat_exec_size=" << oat_exec_size << std::hex << " " << oat_exec_size; 218 } 219 220 // .dynamic 221 // alignment would naturally be sizeof(llvm::ELF::Elf32_Word), but we want this in a new segment 222 uint32_t dynamic_alignment = kPageSize; 223 uint32_t dynamic_offset = expected_offset = RoundUp(expected_offset, dynamic_alignment); 224 const uint8_t DH_SONAME = 0; 225 const uint8_t DH_HASH = 1; 226 const uint8_t DH_SYMTAB = 2; 227 const uint8_t DH_SYMENT = 3; 228 const uint8_t DH_STRTAB = 4; 229 const uint8_t DH_STRSZ = 5; 230 const uint8_t DH_NULL = 6; 231 const uint8_t DH_NUM = 7; 232 uint32_t dynamic_size = sizeof(llvm::ELF::Elf32_Dyn) * DH_NUM; 233 expected_offset += dynamic_size; 234 if (debug) { 235 LOG(INFO) << "dynamic_offset=" << dynamic_offset << std::hex << " " << dynamic_offset; 236 LOG(INFO) << "dynamic_size=" << dynamic_size << std::hex << " " << dynamic_size; 237 } 238 239 // .shstrtab 240 uint32_t shstrtab_alignment = 1; 241 uint32_t shstrtab_offset = expected_offset = RoundUp(expected_offset, shstrtab_alignment); 242 std::string shstrtab; 243 shstrtab += '\0'; 244 uint32_t shstrtab_dynamic_offset = shstrtab.size(); 245 CHECK_EQ(1U, shstrtab_dynamic_offset); 246 shstrtab += ".dynamic"; 247 shstrtab += '\0'; 248 uint32_t shstrtab_dynsym_offset = shstrtab.size(); 249 shstrtab += ".dynsym"; 250 shstrtab += '\0'; 251 uint32_t shstrtab_dynstr_offset = shstrtab.size(); 252 shstrtab += ".dynstr"; 253 shstrtab += '\0'; 254 uint32_t shstrtab_hash_offset = shstrtab.size(); 255 shstrtab += ".hash"; 256 shstrtab += '\0'; 257 uint32_t shstrtab_rodata_offset = shstrtab.size(); 258 shstrtab += ".rodata"; 259 shstrtab += '\0'; 260 uint32_t shstrtab_text_offset = shstrtab.size(); 261 shstrtab += ".text"; 262 shstrtab += '\0'; 263 uint32_t shstrtab_shstrtab_offset = shstrtab.size(); 264 shstrtab += ".shstrtab"; 265 shstrtab += '\0'; 266 uint32_t shstrtab_size = shstrtab.size(); 267 expected_offset += shstrtab_size; 268 if (debug) { 269 LOG(INFO) << "shstrtab_offset=" << shstrtab_offset << std::hex << " " << shstrtab_offset; 270 LOG(INFO) << "shstrtab_size=" << shstrtab_size << std::hex << " " << shstrtab_size; 271 } 272 273 // section headers (after all sections) 274 uint32_t shdr_alignment = sizeof(llvm::ELF::Elf32_Word); 275 uint32_t shdr_offset = expected_offset = RoundUp(expected_offset, shdr_alignment); 276 const uint8_t SH_NULL = 0; 277 const uint8_t SH_DYNSYM = 1; 278 const uint8_t SH_DYNSTR = 2; 279 const uint8_t SH_HASH = 3; 280 const uint8_t SH_RODATA = 4; 281 const uint8_t SH_TEXT = 5; 282 const uint8_t SH_DYNAMIC = 6; 283 const uint8_t SH_SHSTRTAB = 7; 284 const uint8_t SH_NUM = 8; 285 uint32_t shdr_size = sizeof(llvm::ELF::Elf32_Shdr) * SH_NUM; 286 expected_offset += shdr_size; 287 if (debug) { 288 LOG(INFO) << "shdr_offset=" << shdr_offset << std::hex << " " << shdr_offset; 289 LOG(INFO) << "shdr_size=" << shdr_size << std::hex << " " << shdr_size; 290 } 291 292 // phase 2: initializing data 293 294 // Elf32_Ehdr 295 llvm::ELF::Elf32_Ehdr elf_header; 296 memset(&elf_header, 0, sizeof(elf_header)); 297 elf_header.e_ident[llvm::ELF::EI_MAG0] = llvm::ELF::ElfMagic[0]; 298 elf_header.e_ident[llvm::ELF::EI_MAG1] = llvm::ELF::ElfMagic[1]; 299 elf_header.e_ident[llvm::ELF::EI_MAG2] = llvm::ELF::ElfMagic[2]; 300 elf_header.e_ident[llvm::ELF::EI_MAG3] = llvm::ELF::ElfMagic[3]; 301 elf_header.e_ident[llvm::ELF::EI_CLASS] = llvm::ELF::ELFCLASS32; 302 elf_header.e_ident[llvm::ELF::EI_DATA] = llvm::ELF::ELFDATA2LSB; 303 elf_header.e_ident[llvm::ELF::EI_VERSION] = llvm::ELF::EV_CURRENT; 304 elf_header.e_ident[llvm::ELF::EI_OSABI] = llvm::ELF::ELFOSABI_LINUX; 305 elf_header.e_ident[llvm::ELF::EI_ABIVERSION] = 0; 306 elf_header.e_type = llvm::ELF::ET_DYN; 307 switch (compiler_driver_->GetInstructionSet()) { 308 case kThumb2: { 309 elf_header.e_machine = llvm::ELF::EM_ARM; 310 elf_header.e_flags = llvm::ELF::EF_ARM_EABI_VER5; 311 break; 312 } 313 case kX86: { 314 elf_header.e_machine = llvm::ELF::EM_386; 315 elf_header.e_flags = 0; 316 break; 317 } 318 case kMips: { 319 elf_header.e_machine = llvm::ELF::EM_MIPS; 320 elf_header.e_flags = (llvm::ELF::EF_MIPS_NOREORDER | 321 llvm::ELF::EF_MIPS_PIC | 322 llvm::ELF::EF_MIPS_CPIC | 323 llvm::ELF::EF_MIPS_ABI_O32 | 324 llvm::ELF::EF_MIPS_ARCH_32R2); 325 break; 326 } 327 case kArm: 328 default: { 329 LOG(FATAL) << "Unknown instruction set: " << compiler_driver_->GetInstructionSet(); 330 break; 331 } 332 } 333 elf_header.e_version = 1; 334 elf_header.e_entry = 0; 335 elf_header.e_phoff = phdr_offset; 336 elf_header.e_shoff = shdr_offset; 337 elf_header.e_ehsize = sizeof(llvm::ELF::Elf32_Ehdr); 338 elf_header.e_phentsize = sizeof(llvm::ELF::Elf32_Phdr); 339 elf_header.e_phnum = PH_NUM; 340 elf_header.e_shentsize = sizeof(llvm::ELF::Elf32_Shdr); 341 elf_header.e_shnum = SH_NUM; 342 elf_header.e_shstrndx = SH_SHSTRTAB; 343 344 // PHDR 345 llvm::ELF::Elf32_Phdr program_headers[PH_NUM]; 346 memset(&program_headers, 0, sizeof(program_headers)); 347 348 program_headers[PH_PHDR].p_type = llvm::ELF::PT_PHDR; 349 program_headers[PH_PHDR].p_offset = phdr_offset; 350 program_headers[PH_PHDR].p_vaddr = phdr_offset; 351 program_headers[PH_PHDR].p_paddr = phdr_offset; 352 program_headers[PH_PHDR].p_filesz = sizeof(program_headers); 353 program_headers[PH_PHDR].p_memsz = sizeof(program_headers); 354 program_headers[PH_PHDR].p_flags = llvm::ELF::PF_R; 355 program_headers[PH_PHDR].p_align = phdr_alignment; 356 357 program_headers[PH_LOAD_R__].p_type = llvm::ELF::PT_LOAD; 358 program_headers[PH_LOAD_R__].p_offset = 0; 359 program_headers[PH_LOAD_R__].p_vaddr = 0; 360 program_headers[PH_LOAD_R__].p_paddr = 0; 361 program_headers[PH_LOAD_R__].p_filesz = oat_data_offset + oat_data_size; 362 program_headers[PH_LOAD_R__].p_memsz = oat_data_offset + oat_data_size; 363 program_headers[PH_LOAD_R__].p_flags = llvm::ELF::PF_R; 364 program_headers[PH_LOAD_R__].p_align = oat_data_alignment; 365 366 program_headers[PH_LOAD_R_X].p_type = llvm::ELF::PT_LOAD; 367 program_headers[PH_LOAD_R_X].p_offset = oat_exec_offset; 368 program_headers[PH_LOAD_R_X].p_vaddr = oat_exec_offset; 369 program_headers[PH_LOAD_R_X].p_paddr = oat_exec_offset; 370 program_headers[PH_LOAD_R_X].p_filesz = oat_exec_size; 371 program_headers[PH_LOAD_R_X].p_memsz = oat_exec_size; 372 program_headers[PH_LOAD_R_X].p_flags = llvm::ELF::PF_R | llvm::ELF::PF_X; 373 program_headers[PH_LOAD_R_X].p_align = oat_exec_alignment; 374 375 // TODO: PF_W for DYNAMIC is considered processor specific, do we need it? 376 program_headers[PH_LOAD_RW_].p_type = llvm::ELF::PT_LOAD; 377 program_headers[PH_LOAD_RW_].p_offset = dynamic_offset; 378 program_headers[PH_LOAD_RW_].p_vaddr = dynamic_offset; 379 program_headers[PH_LOAD_RW_].p_paddr = dynamic_offset; 380 program_headers[PH_LOAD_RW_].p_filesz = dynamic_size; 381 program_headers[PH_LOAD_RW_].p_memsz = dynamic_size; 382 program_headers[PH_LOAD_RW_].p_flags = llvm::ELF::PF_R | llvm::ELF::PF_W; 383 program_headers[PH_LOAD_RW_].p_align = dynamic_alignment; 384 385 // TODO: PF_W for DYNAMIC is considered processor specific, do we need it? 386 program_headers[PH_DYNAMIC].p_type = llvm::ELF::PT_DYNAMIC; 387 program_headers[PH_DYNAMIC].p_offset = dynamic_offset; 388 program_headers[PH_DYNAMIC].p_vaddr = dynamic_offset; 389 program_headers[PH_DYNAMIC].p_paddr = dynamic_offset; 390 program_headers[PH_DYNAMIC].p_filesz = dynamic_size; 391 program_headers[PH_DYNAMIC].p_memsz = dynamic_size; 392 program_headers[PH_DYNAMIC].p_flags = llvm::ELF::PF_R | llvm::ELF::PF_W; 393 program_headers[PH_DYNAMIC].p_align = dynamic_alignment; 394 395 // .dynsym 396 llvm::ELF::Elf32_Sym dynsym[SYM_NUM]; 397 memset(&dynsym, 0, sizeof(dynsym)); 398 399 dynsym[SYM_UNDEF].st_name = 0; 400 dynsym[SYM_UNDEF].st_value = 0; 401 dynsym[SYM_UNDEF].st_size = 0; 402 dynsym[SYM_UNDEF].st_info = 0; 403 dynsym[SYM_UNDEF].st_other = 0; 404 dynsym[SYM_UNDEF].st_shndx = 0; 405 406 dynsym[SYM_OATDATA].st_name = dynstr_oatdata_offset; 407 dynsym[SYM_OATDATA].st_value = oat_data_offset; 408 dynsym[SYM_OATDATA].st_size = oat_data_size; 409 dynsym[SYM_OATDATA].setBindingAndType(llvm::ELF::STB_GLOBAL, llvm::ELF::STT_OBJECT); 410 dynsym[SYM_OATDATA].st_other = llvm::ELF::STV_DEFAULT; 411 dynsym[SYM_OATDATA].st_shndx = SH_RODATA; 412 413 dynsym[SYM_OATEXEC].st_name = dynstr_oatexec_offset; 414 dynsym[SYM_OATEXEC].st_value = oat_exec_offset; 415 dynsym[SYM_OATEXEC].st_size = oat_exec_size; 416 dynsym[SYM_OATEXEC].setBindingAndType(llvm::ELF::STB_GLOBAL, llvm::ELF::STT_OBJECT); 417 dynsym[SYM_OATEXEC].st_other = llvm::ELF::STV_DEFAULT; 418 dynsym[SYM_OATEXEC].st_shndx = SH_TEXT; 419 420 dynsym[SYM_OATLASTWORD].st_name = dynstr_oatlastword_offset; 421 dynsym[SYM_OATLASTWORD].st_value = oat_exec_offset + oat_exec_size - 4; 422 dynsym[SYM_OATLASTWORD].st_size = 4; 423 dynsym[SYM_OATLASTWORD].setBindingAndType(llvm::ELF::STB_GLOBAL, llvm::ELF::STT_OBJECT); 424 dynsym[SYM_OATLASTWORD].st_other = llvm::ELF::STV_DEFAULT; 425 dynsym[SYM_OATLASTWORD].st_shndx = SH_TEXT; 426 427 // .dynstr initialized above as dynstr 428 429 // .hash 430 llvm::ELF::Elf32_Word hash[HASH_NUM]; // Note this is Elf32_Word even on 64-bit 431 hash[HASH_NBUCKET] = 1; 432 hash[HASH_NCHAIN] = SYM_NUM; 433 hash[HASH_BUCKET0] = SYM_OATDATA; 434 hash[HASH_BUCKET0 + 1 + SYM_UNDEF] = SYM_UNDEF; 435 hash[HASH_BUCKET0 + 1 + SYM_OATDATA] = SYM_OATEXEC; 436 hash[HASH_BUCKET0 + 1 + SYM_OATEXEC] = SYM_OATLASTWORD; 437 hash[HASH_BUCKET0 + 1 + SYM_OATLASTWORD] = SYM_UNDEF; 438 439 // .rodata and .text content come from oat_contents 440 441 // .dynamic 442 llvm::ELF::Elf32_Dyn dynamic_headers[DH_NUM]; 443 memset(&dynamic_headers, 0, sizeof(dynamic_headers)); 444 445 dynamic_headers[DH_SONAME].d_tag = llvm::ELF::DT_SONAME; 446 dynamic_headers[DH_SONAME].d_un.d_val = dynstr_soname_offset; 447 448 dynamic_headers[DH_HASH].d_tag = llvm::ELF::DT_HASH; 449 dynamic_headers[DH_HASH].d_un.d_ptr = hash_offset; 450 451 dynamic_headers[DH_SYMTAB].d_tag = llvm::ELF::DT_SYMTAB; 452 dynamic_headers[DH_SYMTAB].d_un.d_ptr = dynsym_offset; 453 454 dynamic_headers[DH_SYMENT].d_tag = llvm::ELF::DT_SYMENT; 455 dynamic_headers[DH_SYMENT].d_un.d_val = sizeof(llvm::ELF::Elf32_Sym); 456 457 dynamic_headers[DH_STRTAB].d_tag = llvm::ELF::DT_STRTAB; 458 dynamic_headers[DH_STRTAB].d_un.d_ptr = dynstr_offset; 459 460 dynamic_headers[DH_STRSZ].d_tag = llvm::ELF::DT_STRSZ; 461 dynamic_headers[DH_STRSZ].d_un.d_val = dynstr_size; 462 463 dynamic_headers[DH_NULL].d_tag = llvm::ELF::DT_NULL; 464 dynamic_headers[DH_NULL].d_un.d_val = 0; 465 466 // .shstrtab initialized above as shstrtab 467 468 // section headers (after all sections) 469 llvm::ELF::Elf32_Shdr section_headers[SH_NUM]; 470 memset(§ion_headers, 0, sizeof(section_headers)); 471 472 section_headers[SH_NULL].sh_name = 0; 473 section_headers[SH_NULL].sh_type = llvm::ELF::SHT_NULL; 474 section_headers[SH_NULL].sh_flags = 0; 475 section_headers[SH_NULL].sh_addr = 0; 476 section_headers[SH_NULL].sh_offset = 0; 477 section_headers[SH_NULL].sh_size = 0; 478 section_headers[SH_NULL].sh_link = 0; 479 section_headers[SH_NULL].sh_info = 0; 480 section_headers[SH_NULL].sh_addralign = 0; 481 section_headers[SH_NULL].sh_entsize = 0; 482 483 section_headers[SH_DYNSYM].sh_name = shstrtab_dynsym_offset; 484 section_headers[SH_DYNSYM].sh_type = llvm::ELF::SHT_DYNSYM; 485 section_headers[SH_DYNSYM].sh_flags = llvm::ELF::SHF_ALLOC; 486 section_headers[SH_DYNSYM].sh_addr = dynsym_offset; 487 section_headers[SH_DYNSYM].sh_offset = dynsym_offset; 488 section_headers[SH_DYNSYM].sh_size = dynsym_size; 489 section_headers[SH_DYNSYM].sh_link = SH_DYNSTR; 490 section_headers[SH_DYNSYM].sh_info = 1; // 1 because we have not STB_LOCAL symbols 491 section_headers[SH_DYNSYM].sh_addralign = dynsym_alignment; 492 section_headers[SH_DYNSYM].sh_entsize = sizeof(llvm::ELF::Elf32_Sym); 493 494 section_headers[SH_DYNSTR].sh_name = shstrtab_dynstr_offset; 495 section_headers[SH_DYNSTR].sh_type = llvm::ELF::SHT_STRTAB; 496 section_headers[SH_DYNSTR].sh_flags = llvm::ELF::SHF_ALLOC; 497 section_headers[SH_DYNSTR].sh_addr = dynstr_offset; 498 section_headers[SH_DYNSTR].sh_offset = dynstr_offset; 499 section_headers[SH_DYNSTR].sh_size = dynstr_size; 500 section_headers[SH_DYNSTR].sh_link = 0; 501 section_headers[SH_DYNSTR].sh_info = 0; 502 section_headers[SH_DYNSTR].sh_addralign = dynstr_alignment; 503 section_headers[SH_DYNSTR].sh_entsize = 0; 504 505 section_headers[SH_HASH].sh_name = shstrtab_hash_offset; 506 section_headers[SH_HASH].sh_type = llvm::ELF::SHT_HASH; 507 section_headers[SH_HASH].sh_flags = llvm::ELF::SHF_ALLOC; 508 section_headers[SH_HASH].sh_addr = hash_offset; 509 section_headers[SH_HASH].sh_offset = hash_offset; 510 section_headers[SH_HASH].sh_size = hash_size; 511 section_headers[SH_HASH].sh_link = SH_DYNSYM; 512 section_headers[SH_HASH].sh_info = 0; 513 section_headers[SH_HASH].sh_addralign = hash_alignment; 514 section_headers[SH_HASH].sh_entsize = sizeof(llvm::ELF::Elf32_Word); // This is Elf32_Word even on 64-bit 515 516 section_headers[SH_RODATA].sh_name = shstrtab_rodata_offset; 517 section_headers[SH_RODATA].sh_type = llvm::ELF::SHT_PROGBITS; 518 section_headers[SH_RODATA].sh_flags = llvm::ELF::SHF_ALLOC; 519 section_headers[SH_RODATA].sh_addr = oat_data_offset; 520 section_headers[SH_RODATA].sh_offset = oat_data_offset; 521 section_headers[SH_RODATA].sh_size = oat_data_size; 522 section_headers[SH_RODATA].sh_link = 0; 523 section_headers[SH_RODATA].sh_info = 0; 524 section_headers[SH_RODATA].sh_addralign = oat_data_alignment; 525 section_headers[SH_RODATA].sh_entsize = 0; 526 527 section_headers[SH_TEXT].sh_name = shstrtab_text_offset; 528 section_headers[SH_TEXT].sh_type = llvm::ELF::SHT_PROGBITS; 529 section_headers[SH_TEXT].sh_flags = llvm::ELF::SHF_ALLOC | llvm::ELF::SHF_EXECINSTR; 530 section_headers[SH_TEXT].sh_addr = oat_exec_offset; 531 section_headers[SH_TEXT].sh_offset = oat_exec_offset; 532 section_headers[SH_TEXT].sh_size = oat_exec_size; 533 section_headers[SH_TEXT].sh_link = 0; 534 section_headers[SH_TEXT].sh_info = 0; 535 section_headers[SH_TEXT].sh_addralign = oat_exec_alignment; 536 section_headers[SH_TEXT].sh_entsize = 0; 537 538 // TODO: SHF_WRITE for .dynamic is considered processor specific, do we need it? 539 section_headers[SH_DYNAMIC].sh_name = shstrtab_dynamic_offset; 540 section_headers[SH_DYNAMIC].sh_type = llvm::ELF::SHT_DYNAMIC; 541 section_headers[SH_DYNAMIC].sh_flags = llvm::ELF::SHF_WRITE | llvm::ELF::SHF_ALLOC; 542 section_headers[SH_DYNAMIC].sh_addr = dynamic_offset; 543 section_headers[SH_DYNAMIC].sh_offset = dynamic_offset; 544 section_headers[SH_DYNAMIC].sh_size = dynamic_size; 545 section_headers[SH_DYNAMIC].sh_link = SH_DYNSTR; 546 section_headers[SH_DYNAMIC].sh_info = 0; 547 section_headers[SH_DYNAMIC].sh_addralign = dynamic_alignment; 548 section_headers[SH_DYNAMIC].sh_entsize = sizeof(llvm::ELF::Elf32_Dyn); 549 550 section_headers[SH_SHSTRTAB].sh_name = shstrtab_shstrtab_offset; 551 section_headers[SH_SHSTRTAB].sh_type = llvm::ELF::SHT_STRTAB; 552 section_headers[SH_SHSTRTAB].sh_flags = 0; 553 section_headers[SH_SHSTRTAB].sh_addr = shstrtab_offset; 554 section_headers[SH_SHSTRTAB].sh_offset = shstrtab_offset; 555 section_headers[SH_SHSTRTAB].sh_size = shstrtab_size; 556 section_headers[SH_SHSTRTAB].sh_link = 0; 557 section_headers[SH_SHSTRTAB].sh_info = 0; 558 section_headers[SH_SHSTRTAB].sh_addralign = shstrtab_alignment; 559 section_headers[SH_SHSTRTAB].sh_entsize = 0; 560 561 // phase 3: writing file 562 563 // Elf32_Ehdr 564 if (!elf_file_->WriteFully(&elf_header, sizeof(elf_header))) { 565 PLOG(ERROR) << "Failed to write ELF header for " << elf_file_->GetPath(); 566 return false; 567 } 568 569 // PHDR 570 if (static_cast<off_t>(phdr_offset) != lseek(elf_file_->Fd(), 0, SEEK_CUR)) { 571 PLOG(ERROR) << "Failed to be at expected ELF program header offset phdr_offset " 572 << " for " << elf_file_->GetPath(); 573 return false; 574 } 575 if (!elf_file_->WriteFully(program_headers, sizeof(program_headers))) { 576 PLOG(ERROR) << "Failed to write ELF program headers for " << elf_file_->GetPath(); 577 return false; 578 } 579 580 // .dynsym 581 DCHECK_LE(phdr_offset + phdr_size, dynsym_offset); 582 if (static_cast<off_t>(dynsym_offset) != lseek(elf_file_->Fd(), dynsym_offset, SEEK_SET)) { 583 PLOG(ERROR) << "Failed to seek to .dynsym offset location " << dynsym_offset 584 << " for " << elf_file_->GetPath(); 585 return false; 586 } 587 if (!elf_file_->WriteFully(dynsym, sizeof(dynsym))) { 588 PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath(); 589 return false; 590 } 591 592 // .dynstr 593 DCHECK_LE(dynsym_offset + dynsym_size, dynstr_offset); 594 if (static_cast<off_t>(dynstr_offset) != lseek(elf_file_->Fd(), dynstr_offset, SEEK_SET)) { 595 PLOG(ERROR) << "Failed to seek to .dynstr offset " << dynstr_offset 596 << " for " << elf_file_->GetPath(); 597 return false; 598 } 599 if (!elf_file_->WriteFully(&dynstr[0], dynstr_size)) { 600 PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath(); 601 return false; 602 } 603 604 // .hash 605 DCHECK_LE(dynstr_offset + dynstr_size, hash_offset); 606 if (static_cast<off_t>(hash_offset) != lseek(elf_file_->Fd(), hash_offset, SEEK_SET)) { 607 PLOG(ERROR) << "Failed to seek to .hash offset " << hash_offset 608 << " for " << elf_file_->GetPath(); 609 return false; 610 } 611 if (!elf_file_->WriteFully(hash, sizeof(hash))) { 612 PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath(); 613 return false; 614 } 615 616 // .rodata .text 617 DCHECK_LE(hash_offset + hash_size, oat_data_offset); 618 if (static_cast<off_t>(oat_data_offset) != lseek(elf_file_->Fd(), oat_data_offset, SEEK_SET)) { 619 PLOG(ERROR) << "Failed to seek to .rodata offset " << oat_data_offset 620 << " for " << elf_file_->GetPath(); 621 return false; 622 } 623 BufferedOutputStream output_stream(new FileOutputStream(elf_file_)); 624 if (!oat_writer.Write(output_stream)) { 625 PLOG(ERROR) << "Failed to write .rodata and .text for " << elf_file_->GetPath(); 626 return false; 627 } 628 629 // .dynamic 630 DCHECK_LE(oat_data_offset + oat_writer.GetSize(), dynamic_offset); 631 if (static_cast<off_t>(dynamic_offset) != lseek(elf_file_->Fd(), dynamic_offset, SEEK_SET)) { 632 PLOG(ERROR) << "Failed to seek to .dynamic offset " << dynamic_offset 633 << " for " << elf_file_->GetPath(); 634 return false; 635 } 636 if (!elf_file_->WriteFully(&dynamic_headers[0], dynamic_size)) { 637 PLOG(ERROR) << "Failed to write .dynamic for " << elf_file_->GetPath(); 638 return false; 639 } 640 641 // .shstrtab 642 DCHECK_LE(dynamic_offset + dynamic_size, shstrtab_offset); 643 if (static_cast<off_t>(shstrtab_offset) != lseek(elf_file_->Fd(), shstrtab_offset, SEEK_SET)) { 644 PLOG(ERROR) << "Failed to seek to .shstrtab offset " << shstrtab_offset 645 << " for " << elf_file_->GetPath(); 646 return false; 647 } 648 if (!elf_file_->WriteFully(&shstrtab[0], shstrtab_size)) { 649 PLOG(ERROR) << "Failed to write .shstrtab for " << elf_file_->GetPath(); 650 return false; 651 } 652 653 // section headers (after all sections) 654 DCHECK_LE(shstrtab_offset + shstrtab_size, shdr_offset); 655 if (static_cast<off_t>(shdr_offset) != lseek(elf_file_->Fd(), shdr_offset, SEEK_SET)) { 656 PLOG(ERROR) << "Failed to seek to ELF section headers offset " << shdr_offset 657 << " for " << elf_file_->GetPath(); 658 return false; 659 } 660 if (!elf_file_->WriteFully(section_headers, sizeof(section_headers))) { 661 PLOG(ERROR) << "Failed to write ELF section headers for " << elf_file_->GetPath(); 662 return false; 663 } 664 665 VLOG(compiler) << "ELF file written successfully: " << elf_file_->GetPath(); 666 return true; 667 } 668 669 } // namespace art 670
