elf_writer_quick.cc revision 8718359763aa3dcd0033a2d2e67e0cb145fb9c53
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 "driver/compiler_driver.h" 22#include "file_output_stream.h" 23#include "globals.h" 24#include "oat.h" 25#include "oat_writer.h" 26#include "utils.h" 27 28namespace art { 29 30ElfWriterQuick::ElfWriterQuick(const CompilerDriver& driver, File* elf_file) 31 : ElfWriter(driver, elf_file) {} 32 33ElfWriterQuick::~ElfWriterQuick() {} 34 35bool ElfWriterQuick::Create(File* elf_file, 36 OatWriter& oat_writer, 37 const std::vector<const DexFile*>& dex_files, 38 const std::string& android_root, 39 bool is_host, 40 const CompilerDriver& driver) { 41 ElfWriterQuick elf_writer(driver, elf_file); 42 return elf_writer.Write(oat_writer, dex_files, android_root, is_host); 43} 44 45bool ElfWriterQuick::Write(OatWriter& oat_writer, 46 const std::vector<const DexFile*>& dex_files_unused, 47 const std::string& android_root_unused, 48 bool is_host_unused) { 49 const bool debug = false; 50 // +-------------------------+ 51 // | Elf32_Ehdr | 52 // +-------------------------+ 53 // | Elf32_Phdr PHDR | 54 // | Elf32_Phdr LOAD R | .dynsym .dynstr .hash .rodata 55 // | Elf32_Phdr LOAD R X | .text 56 // | Elf32_Phdr LOAD RW | .dynamic 57 // | Elf32_Phdr DYNAMIC | .dynamic 58 // +-------------------------+ 59 // | .dynsym | 60 // | Elf32_Sym STN_UNDEF | 61 // | Elf32_Sym oatdata | 62 // | Elf32_Sym oatexec | 63 // | Elf32_Sym oatlastword | 64 // +-------------------------+ 65 // | .dynstr | 66 // | \0 | 67 // | oatdata\0 | 68 // | oatexec\0 | 69 // | oatlastword\0 | 70 // | boot.oat\0 | 71 // +-------------------------+ 72 // | .hash | 73 // | Elf32_Word nbucket = 1 | 74 // | Elf32_Word nchain = 3 | 75 // | Elf32_Word bucket[0] = 0| 76 // | Elf32_Word chain[0] = 1| 77 // | Elf32_Word chain[1] = 2| 78 // | Elf32_Word chain[2] = 3| 79 // +-------------------------+ 80 // | .rodata | 81 // | oatdata..oatexec-4 | 82 // +-------------------------+ 83 // | .text | 84 // | oatexec..oatlastword | 85 // +-------------------------+ 86 // | .dynamic | 87 // | Elf32_Dyn DT_SONAME | 88 // | Elf32_Dyn DT_HASH | 89 // | Elf32_Dyn DT_SYMTAB | 90 // | Elf32_Dyn DT_SYMENT | 91 // | Elf32_Dyn DT_STRTAB | 92 // | Elf32_Dyn DT_STRSZ | 93 // | Elf32_Dyn DT_NULL | 94 // +-------------------------+ 95 // | .shstrtab | 96 // | \0 | 97 // | .dynamic\0 | 98 // | .dynsym\0 | 99 // | .dynstr\0 | 100 // | .hash\0 | 101 // | .rodata\0 | 102 // | .text\0 | 103 // | .shstrtab\0 | 104 // +-------------------------+ 105 // | Elf32_Shdr NULL | 106 // | Elf32_Shdr .dynsym | 107 // | Elf32_Shdr .dynstr | 108 // | Elf32_Shdr .hash | 109 // | Elf32_Shdr .text | 110 // | Elf32_Shdr .rodata | 111 // | Elf32_Shdr .dynamic | 112 // | Elf32_Shdr .shstrtab | 113 // +-------------------------+ 114 115 // phase 1: computing offsets 116 uint32_t expected_offset = 0; 117 118 // Elf32_Ehdr 119 expected_offset += sizeof(llvm::ELF::Elf32_Ehdr); 120 121 // PHDR 122 uint32_t phdr_alignment = sizeof(llvm::ELF::Elf32_Word); 123 uint32_t phdr_offset = expected_offset; 124 const uint8_t PH_PHDR = 0; 125 const uint8_t PH_LOAD_R__ = 1; 126 const uint8_t PH_LOAD_R_X = 2; 127 const uint8_t PH_LOAD_RW_ = 3; 128 const uint8_t PH_DYNAMIC = 4; 129 const uint8_t PH_NUM = 5; 130 uint32_t phdr_size = sizeof(llvm::ELF::Elf32_Phdr) * PH_NUM; 131 expected_offset += phdr_size; 132 if (debug) { 133 LOG(INFO) << "phdr_offset=" << phdr_offset << std::hex << " " << phdr_offset; 134 LOG(INFO) << "phdr_size=" << phdr_size << std::hex << " " << phdr_size; 135 } 136 137 // .dynsym 138 uint32_t dynsym_alignment = sizeof(llvm::ELF::Elf32_Word); 139 uint32_t dynsym_offset = expected_offset = RoundUp(expected_offset, dynsym_alignment); 140 const uint8_t SYM_UNDEF = 0; // aka STN_UNDEF 141 const uint8_t SYM_OATDATA = 1; 142 const uint8_t SYM_OATEXEC = 2; 143 const uint8_t SYM_OATLASTWORD = 3; 144 const uint8_t SYM_NUM = 4; 145 uint32_t dynsym_size = sizeof(llvm::ELF::Elf32_Sym) * SYM_NUM; 146 expected_offset += dynsym_size; 147 if (debug) { 148 LOG(INFO) << "dynsym_offset=" << dynsym_offset << std::hex << " " << dynsym_offset; 149 LOG(INFO) << "dynsym_size=" << dynsym_size << std::hex << " " << dynsym_size; 150 } 151 152 // .dynstr 153 uint32_t dynstr_alignment = 1; 154 uint32_t dynstr_offset = expected_offset = RoundUp(expected_offset, dynstr_alignment); 155 std::string dynstr; 156 dynstr += '\0'; 157 uint32_t dynstr_oatdata_offset = dynstr.size(); 158 dynstr += "oatdata"; 159 dynstr += '\0'; 160 uint32_t dynstr_oatexec_offset = dynstr.size(); 161 dynstr += "oatexec"; 162 dynstr += '\0'; 163 uint32_t dynstr_oatlastword_offset = dynstr.size(); 164 dynstr += "oatlastword"; 165 dynstr += '\0'; 166 uint32_t dynstr_soname_offset = dynstr.size(); 167 std::string file_name(elf_file_->GetPath()); 168 size_t directory_separator_pos = file_name.rfind('/'); 169 if (directory_separator_pos != std::string::npos) { 170 file_name = file_name.substr(directory_separator_pos + 1); 171 } 172 dynstr += file_name; 173 dynstr += '\0'; 174 uint32_t dynstr_size = dynstr.size(); 175 expected_offset += dynstr_size; 176 if (debug) { 177 LOG(INFO) << "dynstr_offset=" << dynstr_offset << std::hex << " " << dynstr_offset; 178 LOG(INFO) << "dynstr_size=" << dynstr_size << std::hex << " " << dynstr_size; 179 } 180 181 // .hash 182 uint32_t hash_alignment = sizeof(llvm::ELF::Elf32_Word); // Even for 64-bit 183 uint32_t hash_offset = expected_offset = RoundUp(expected_offset, hash_alignment); 184 const uint8_t HASH_NBUCKET = 0; 185 const uint8_t HASH_NCHAIN = 1; 186 const uint8_t HASH_BUCKET0 = 2; 187 const uint8_t HASH_NUM = HASH_BUCKET0 + 1 + SYM_NUM; 188 uint32_t hash_size = sizeof(llvm::ELF::Elf32_Word) * HASH_NUM; 189 expected_offset += hash_size; 190 if (debug) { 191 LOG(INFO) << "hash_offset=" << hash_offset << std::hex << " " << hash_offset; 192 LOG(INFO) << "hash_size=" << hash_size << std::hex << " " << hash_size; 193 } 194 195 // .rodata 196 uint32_t oat_data_alignment = kPageSize; 197 uint32_t oat_data_offset = expected_offset = RoundUp(expected_offset, oat_data_alignment); 198 const OatHeader& oat_header = oat_writer.GetOatHeader(); 199 CHECK(oat_header.IsValid()); 200 uint32_t oat_data_size = oat_header.GetExecutableOffset(); 201 expected_offset += oat_data_size; 202 if (debug) { 203 LOG(INFO) << "oat_data_offset=" << oat_data_offset << std::hex << " " << oat_data_offset; 204 LOG(INFO) << "oat_data_size=" << oat_data_size << std::hex << " " << oat_data_size; 205 } 206 207 // .text 208 uint32_t oat_exec_alignment = kPageSize; 209 CHECK_ALIGNED(expected_offset, kPageSize); 210 uint32_t oat_exec_offset = expected_offset = RoundUp(expected_offset, oat_exec_alignment); 211 uint32_t oat_exec_size = oat_writer.GetSize() - oat_data_size; 212 expected_offset += oat_exec_size; 213 CHECK_EQ(oat_data_offset + oat_writer.GetSize(), expected_offset); 214 if (debug) { 215 LOG(INFO) << "oat_exec_offset=" << oat_exec_offset << std::hex << " " << oat_exec_offset; 216 LOG(INFO) << "oat_exec_size=" << oat_exec_size << std::hex << " " << oat_exec_size; 217 } 218 219 // .dynamic 220 // alignment would naturally be sizeof(llvm::ELF::Elf32_Word), but we want this in a new segment 221 uint32_t dynamic_alignment = kPageSize; 222 uint32_t dynamic_offset = expected_offset = RoundUp(expected_offset, dynamic_alignment); 223 const uint8_t DH_SONAME = 0; 224 const uint8_t DH_HASH = 1; 225 const uint8_t DH_SYMTAB = 2; 226 const uint8_t DH_SYMENT = 3; 227 const uint8_t DH_STRTAB = 4; 228 const uint8_t DH_STRSZ = 5; 229 const uint8_t DH_NULL = 6; 230 const uint8_t DH_NUM = 7; 231 uint32_t dynamic_size = sizeof(llvm::ELF::Elf32_Dyn) * DH_NUM; 232 expected_offset += dynamic_size; 233 if (debug) { 234 LOG(INFO) << "dynamic_offset=" << dynamic_offset << std::hex << " " << dynamic_offset; 235 LOG(INFO) << "dynamic_size=" << dynamic_size << std::hex << " " << dynamic_size; 236 } 237 238 // .shstrtab 239 uint32_t shstrtab_alignment = 1; 240 uint32_t shstrtab_offset = expected_offset = RoundUp(expected_offset, shstrtab_alignment); 241 std::string shstrtab; 242 shstrtab += '\0'; 243 uint32_t shstrtab_dynamic_offset = shstrtab.size(); 244 CHECK_EQ(1U, shstrtab_dynamic_offset); 245 shstrtab += ".dynamic"; 246 shstrtab += '\0'; 247 uint32_t shstrtab_dynsym_offset = shstrtab.size(); 248 shstrtab += ".dynsym"; 249 shstrtab += '\0'; 250 uint32_t shstrtab_dynstr_offset = shstrtab.size(); 251 shstrtab += ".dynstr"; 252 shstrtab += '\0'; 253 uint32_t shstrtab_hash_offset = shstrtab.size(); 254 shstrtab += ".hash"; 255 shstrtab += '\0'; 256 uint32_t shstrtab_rodata_offset = shstrtab.size(); 257 shstrtab += ".rodata"; 258 shstrtab += '\0'; 259 uint32_t shstrtab_text_offset = shstrtab.size(); 260 shstrtab += ".text"; 261 shstrtab += '\0'; 262 uint32_t shstrtab_shstrtab_offset = shstrtab.size(); 263 shstrtab += ".shstrtab"; 264 shstrtab += '\0'; 265 uint32_t shstrtab_size = shstrtab.size(); 266 expected_offset += shstrtab_size; 267 if (debug) { 268 LOG(INFO) << "shstrtab_offset=" << shstrtab_offset << std::hex << " " << shstrtab_offset; 269 LOG(INFO) << "shstrtab_size=" << shstrtab_size << std::hex << " " << shstrtab_size; 270 } 271 272 // section headers (after all sections) 273 uint32_t shdr_alignment = sizeof(llvm::ELF::Elf32_Word); 274 uint32_t shdr_offset = expected_offset = RoundUp(expected_offset, shdr_alignment); 275 const uint8_t SH_NULL = 0; 276 const uint8_t SH_DYNSYM = 1; 277 const uint8_t SH_DYNSTR = 2; 278 const uint8_t SH_HASH = 3; 279 const uint8_t SH_RODATA = 4; 280 const uint8_t SH_TEXT = 5; 281 const uint8_t SH_DYNAMIC = 6; 282 const uint8_t SH_SHSTRTAB = 7; 283 const uint8_t SH_NUM = 8; 284 uint32_t shdr_size = sizeof(llvm::ELF::Elf32_Shdr) * SH_NUM; 285 expected_offset += shdr_size; 286 if (debug) { 287 LOG(INFO) << "shdr_offset=" << shdr_offset << std::hex << " " << shdr_offset; 288 LOG(INFO) << "shdr_size=" << shdr_size << std::hex << " " << shdr_size; 289 } 290 291 // phase 2: initializing data 292 293 // Elf32_Ehdr 294 llvm::ELF::Elf32_Ehdr elf_header; 295 memset(&elf_header, 0, sizeof(elf_header)); 296 elf_header.e_ident[llvm::ELF::EI_MAG0] = llvm::ELF::ElfMagic[0]; 297 elf_header.e_ident[llvm::ELF::EI_MAG1] = llvm::ELF::ElfMagic[1]; 298 elf_header.e_ident[llvm::ELF::EI_MAG2] = llvm::ELF::ElfMagic[2]; 299 elf_header.e_ident[llvm::ELF::EI_MAG3] = llvm::ELF::ElfMagic[3]; 300 elf_header.e_ident[llvm::ELF::EI_CLASS] = llvm::ELF::ELFCLASS32; 301 elf_header.e_ident[llvm::ELF::EI_DATA] = llvm::ELF::ELFDATA2LSB; 302 elf_header.e_ident[llvm::ELF::EI_VERSION] = llvm::ELF::EV_CURRENT; 303 elf_header.e_ident[llvm::ELF::EI_OSABI] = llvm::ELF::ELFOSABI_LINUX; 304 elf_header.e_ident[llvm::ELF::EI_ABIVERSION] = 0; 305 elf_header.e_type = llvm::ELF::ET_DYN; 306 switch (compiler_driver_->GetInstructionSet()) { 307 case kThumb2: { 308 elf_header.e_machine = llvm::ELF::EM_ARM; 309 elf_header.e_flags = llvm::ELF::EF_ARM_EABI_VER5; 310 break; 311 } 312 case kX86: { 313 elf_header.e_machine = llvm::ELF::EM_386; 314 elf_header.e_flags = 0; 315 break; 316 } 317 case kMips: { 318 elf_header.e_machine = llvm::ELF::EM_MIPS; 319 elf_header.e_flags = (llvm::ELF::EF_MIPS_NOREORDER | 320 llvm::ELF::EF_MIPS_PIC | 321 llvm::ELF::EF_MIPS_CPIC | 322 llvm::ELF::EF_MIPS_ABI_O32 | 323 llvm::ELF::EF_MIPS_ARCH_32R2); 324 break; 325 } 326 case kArm: 327 default: { 328 LOG(FATAL) << "Unknown instruction set: " << compiler_driver_->GetInstructionSet(); 329 break; 330 } 331 } 332 elf_header.e_version = 1; 333 elf_header.e_entry = 0; 334 elf_header.e_phoff = phdr_offset; 335 elf_header.e_shoff = shdr_offset; 336 elf_header.e_ehsize = sizeof(llvm::ELF::Elf32_Ehdr); 337 elf_header.e_phentsize = sizeof(llvm::ELF::Elf32_Phdr); 338 elf_header.e_phnum = PH_NUM; 339 elf_header.e_shentsize = sizeof(llvm::ELF::Elf32_Shdr); 340 elf_header.e_shnum = SH_NUM; 341 elf_header.e_shstrndx = SH_SHSTRTAB; 342 343 // PHDR 344 llvm::ELF::Elf32_Phdr program_headers[PH_NUM]; 345 memset(&program_headers, 0, sizeof(program_headers)); 346 347 program_headers[PH_PHDR].p_type = llvm::ELF::PT_PHDR; 348 program_headers[PH_PHDR].p_offset = phdr_offset; 349 program_headers[PH_PHDR].p_vaddr = phdr_offset; 350 program_headers[PH_PHDR].p_paddr = phdr_offset; 351 program_headers[PH_PHDR].p_filesz = sizeof(program_headers); 352 program_headers[PH_PHDR].p_memsz = sizeof(program_headers); 353 program_headers[PH_PHDR].p_flags = llvm::ELF::PF_R; 354 program_headers[PH_PHDR].p_align = phdr_alignment; 355 356 program_headers[PH_LOAD_R__].p_type = llvm::ELF::PT_LOAD; 357 program_headers[PH_LOAD_R__].p_offset = 0; 358 program_headers[PH_LOAD_R__].p_vaddr = 0; 359 program_headers[PH_LOAD_R__].p_paddr = 0; 360 program_headers[PH_LOAD_R__].p_filesz = oat_data_offset + oat_data_size; 361 program_headers[PH_LOAD_R__].p_memsz = oat_data_offset + oat_data_size; 362 program_headers[PH_LOAD_R__].p_flags = llvm::ELF::PF_R; 363 program_headers[PH_LOAD_R__].p_align = oat_data_alignment; 364 365 program_headers[PH_LOAD_R_X].p_type = llvm::ELF::PT_LOAD; 366 program_headers[PH_LOAD_R_X].p_offset = oat_exec_offset; 367 program_headers[PH_LOAD_R_X].p_vaddr = oat_exec_offset; 368 program_headers[PH_LOAD_R_X].p_paddr = oat_exec_offset; 369 program_headers[PH_LOAD_R_X].p_filesz = oat_exec_size; 370 program_headers[PH_LOAD_R_X].p_memsz = oat_exec_size; 371 program_headers[PH_LOAD_R_X].p_flags = llvm::ELF::PF_R | llvm::ELF::PF_X; 372 program_headers[PH_LOAD_R_X].p_align = oat_exec_alignment; 373 374 // TODO: PF_W for DYNAMIC is considered processor specific, do we need it? 375 program_headers[PH_LOAD_RW_].p_type = llvm::ELF::PT_LOAD; 376 program_headers[PH_LOAD_RW_].p_offset = dynamic_offset; 377 program_headers[PH_LOAD_RW_].p_vaddr = dynamic_offset; 378 program_headers[PH_LOAD_RW_].p_paddr = dynamic_offset; 379 program_headers[PH_LOAD_RW_].p_filesz = dynamic_size; 380 program_headers[PH_LOAD_RW_].p_memsz = dynamic_size; 381 program_headers[PH_LOAD_RW_].p_flags = llvm::ELF::PF_R | llvm::ELF::PF_W; 382 program_headers[PH_LOAD_RW_].p_align = dynamic_alignment; 383 384 // TODO: PF_W for DYNAMIC is considered processor specific, do we need it? 385 program_headers[PH_DYNAMIC].p_type = llvm::ELF::PT_DYNAMIC; 386 program_headers[PH_DYNAMIC].p_offset = dynamic_offset; 387 program_headers[PH_DYNAMIC].p_vaddr = dynamic_offset; 388 program_headers[PH_DYNAMIC].p_paddr = dynamic_offset; 389 program_headers[PH_DYNAMIC].p_filesz = dynamic_size; 390 program_headers[PH_DYNAMIC].p_memsz = dynamic_size; 391 program_headers[PH_DYNAMIC].p_flags = llvm::ELF::PF_R | llvm::ELF::PF_W; 392 program_headers[PH_DYNAMIC].p_align = dynamic_alignment; 393 394 // .dynsym 395 llvm::ELF::Elf32_Sym dynsym[SYM_NUM]; 396 memset(&dynsym, 0, sizeof(dynsym)); 397 398 dynsym[SYM_UNDEF].st_name = 0; 399 dynsym[SYM_UNDEF].st_value = 0; 400 dynsym[SYM_UNDEF].st_size = 0; 401 dynsym[SYM_UNDEF].st_info = 0; 402 dynsym[SYM_UNDEF].st_other = 0; 403 dynsym[SYM_UNDEF].st_shndx = 0; 404 405 dynsym[SYM_OATDATA].st_name = dynstr_oatdata_offset; 406 dynsym[SYM_OATDATA].st_value = oat_data_offset; 407 dynsym[SYM_OATDATA].st_size = oat_data_size; 408 dynsym[SYM_OATDATA].setBindingAndType(llvm::ELF::STB_GLOBAL, llvm::ELF::STT_OBJECT); 409 dynsym[SYM_OATDATA].st_other = llvm::ELF::STV_DEFAULT; 410 dynsym[SYM_OATDATA].st_shndx = SH_RODATA; 411 412 dynsym[SYM_OATEXEC].st_name = dynstr_oatexec_offset; 413 dynsym[SYM_OATEXEC].st_value = oat_exec_offset; 414 dynsym[SYM_OATEXEC].st_size = oat_exec_size; 415 dynsym[SYM_OATEXEC].setBindingAndType(llvm::ELF::STB_GLOBAL, llvm::ELF::STT_OBJECT); 416 dynsym[SYM_OATEXEC].st_other = llvm::ELF::STV_DEFAULT; 417 dynsym[SYM_OATEXEC].st_shndx = SH_TEXT; 418 419 dynsym[SYM_OATLASTWORD].st_name = dynstr_oatlastword_offset; 420 dynsym[SYM_OATLASTWORD].st_value = oat_exec_offset + oat_exec_size - 4; 421 dynsym[SYM_OATLASTWORD].st_size = 4; 422 dynsym[SYM_OATLASTWORD].setBindingAndType(llvm::ELF::STB_GLOBAL, llvm::ELF::STT_OBJECT); 423 dynsym[SYM_OATLASTWORD].st_other = llvm::ELF::STV_DEFAULT; 424 dynsym[SYM_OATLASTWORD].st_shndx = SH_TEXT; 425 426 // .dynstr initialized above as dynstr 427 428 // .hash 429 llvm::ELF::Elf32_Word hash[HASH_NUM]; // Note this is Elf32_Word even on 64-bit 430 hash[HASH_NBUCKET] = 1; 431 hash[HASH_NCHAIN] = SYM_NUM; 432 hash[HASH_BUCKET0] = SYM_OATDATA; 433 hash[HASH_BUCKET0 + 1 + SYM_UNDEF] = SYM_UNDEF; 434 hash[HASH_BUCKET0 + 1 + SYM_OATDATA] = SYM_OATEXEC; 435 hash[HASH_BUCKET0 + 1 + SYM_OATEXEC] = SYM_OATLASTWORD; 436 hash[HASH_BUCKET0 + 1 + SYM_OATLASTWORD] = SYM_UNDEF; 437 438 // .rodata and .text content come from oat_contents 439 440 // .dynamic 441 llvm::ELF::Elf32_Dyn dynamic_headers[DH_NUM]; 442 memset(&dynamic_headers, 0, sizeof(dynamic_headers)); 443 444 dynamic_headers[DH_SONAME].d_tag = llvm::ELF::DT_SONAME; 445 dynamic_headers[DH_SONAME].d_un.d_val = dynstr_soname_offset; 446 447 dynamic_headers[DH_HASH].d_tag = llvm::ELF::DT_HASH; 448 dynamic_headers[DH_HASH].d_un.d_ptr = hash_offset; 449 450 dynamic_headers[DH_SYMTAB].d_tag = llvm::ELF::DT_SYMTAB; 451 dynamic_headers[DH_SYMTAB].d_un.d_ptr = dynsym_offset; 452 453 dynamic_headers[DH_SYMENT].d_tag = llvm::ELF::DT_SYMENT; 454 dynamic_headers[DH_SYMENT].d_un.d_val = sizeof(llvm::ELF::Elf32_Sym); 455 456 dynamic_headers[DH_STRTAB].d_tag = llvm::ELF::DT_STRTAB; 457 dynamic_headers[DH_STRTAB].d_un.d_ptr = dynstr_offset; 458 459 dynamic_headers[DH_STRSZ].d_tag = llvm::ELF::DT_STRSZ; 460 dynamic_headers[DH_STRSZ].d_un.d_val = dynstr_size; 461 462 dynamic_headers[DH_NULL].d_tag = llvm::ELF::DT_NULL; 463 dynamic_headers[DH_NULL].d_un.d_val = 0; 464 465 // .shstrtab initialized above as shstrtab 466 467 // section headers (after all sections) 468 llvm::ELF::Elf32_Shdr section_headers[SH_NUM]; 469 memset(§ion_headers, 0, sizeof(section_headers)); 470 471 section_headers[SH_NULL].sh_name = 0; 472 section_headers[SH_NULL].sh_type = llvm::ELF::SHT_NULL; 473 section_headers[SH_NULL].sh_flags = 0; 474 section_headers[SH_NULL].sh_addr = 0; 475 section_headers[SH_NULL].sh_offset = 0; 476 section_headers[SH_NULL].sh_size = 0; 477 section_headers[SH_NULL].sh_link = 0; 478 section_headers[SH_NULL].sh_info = 0; 479 section_headers[SH_NULL].sh_addralign = 0; 480 section_headers[SH_NULL].sh_entsize = 0; 481 482 section_headers[SH_DYNSYM].sh_name = shstrtab_dynsym_offset; 483 section_headers[SH_DYNSYM].sh_type = llvm::ELF::SHT_DYNSYM; 484 section_headers[SH_DYNSYM].sh_flags = llvm::ELF::SHF_ALLOC; 485 section_headers[SH_DYNSYM].sh_addr = dynsym_offset; 486 section_headers[SH_DYNSYM].sh_offset = dynsym_offset; 487 section_headers[SH_DYNSYM].sh_size = dynsym_size; 488 section_headers[SH_DYNSYM].sh_link = SH_DYNSTR; 489 section_headers[SH_DYNSYM].sh_info = 1; // 1 because we have not STB_LOCAL symbols 490 section_headers[SH_DYNSYM].sh_addralign = dynsym_alignment; 491 section_headers[SH_DYNSYM].sh_entsize = sizeof(llvm::ELF::Elf32_Sym); 492 493 section_headers[SH_DYNSTR].sh_name = shstrtab_dynstr_offset; 494 section_headers[SH_DYNSTR].sh_type = llvm::ELF::SHT_STRTAB; 495 section_headers[SH_DYNSTR].sh_flags = llvm::ELF::SHF_ALLOC; 496 section_headers[SH_DYNSTR].sh_addr = dynstr_offset; 497 section_headers[SH_DYNSTR].sh_offset = dynstr_offset; 498 section_headers[SH_DYNSTR].sh_size = dynstr_size; 499 section_headers[SH_DYNSTR].sh_link = 0; 500 section_headers[SH_DYNSTR].sh_info = 0; 501 section_headers[SH_DYNSTR].sh_addralign = dynstr_alignment; 502 section_headers[SH_DYNSTR].sh_entsize = 0; 503 504 section_headers[SH_HASH].sh_name = shstrtab_hash_offset; 505 section_headers[SH_HASH].sh_type = llvm::ELF::SHT_HASH; 506 section_headers[SH_HASH].sh_flags = llvm::ELF::SHF_ALLOC; 507 section_headers[SH_HASH].sh_addr = hash_offset; 508 section_headers[SH_HASH].sh_offset = hash_offset; 509 section_headers[SH_HASH].sh_size = hash_size; 510 section_headers[SH_HASH].sh_link = SH_DYNSYM; 511 section_headers[SH_HASH].sh_info = 0; 512 section_headers[SH_HASH].sh_addralign = hash_alignment; 513 section_headers[SH_HASH].sh_entsize = sizeof(llvm::ELF::Elf32_Word); // This is Elf32_Word even on 64-bit 514 515 section_headers[SH_RODATA].sh_name = shstrtab_rodata_offset; 516 section_headers[SH_RODATA].sh_type = llvm::ELF::SHT_PROGBITS; 517 section_headers[SH_RODATA].sh_flags = llvm::ELF::SHF_ALLOC; 518 section_headers[SH_RODATA].sh_addr = oat_data_offset; 519 section_headers[SH_RODATA].sh_offset = oat_data_offset; 520 section_headers[SH_RODATA].sh_size = oat_data_size; 521 section_headers[SH_RODATA].sh_link = 0; 522 section_headers[SH_RODATA].sh_info = 0; 523 section_headers[SH_RODATA].sh_addralign = oat_data_alignment; 524 section_headers[SH_RODATA].sh_entsize = 0; 525 526 section_headers[SH_TEXT].sh_name = shstrtab_text_offset; 527 section_headers[SH_TEXT].sh_type = llvm::ELF::SHT_PROGBITS; 528 section_headers[SH_TEXT].sh_flags = llvm::ELF::SHF_ALLOC | llvm::ELF::SHF_EXECINSTR; 529 section_headers[SH_TEXT].sh_addr = oat_exec_offset; 530 section_headers[SH_TEXT].sh_offset = oat_exec_offset; 531 section_headers[SH_TEXT].sh_size = oat_exec_size; 532 section_headers[SH_TEXT].sh_link = 0; 533 section_headers[SH_TEXT].sh_info = 0; 534 section_headers[SH_TEXT].sh_addralign = oat_exec_alignment; 535 section_headers[SH_TEXT].sh_entsize = 0; 536 537 // TODO: SHF_WRITE for .dynamic is considered processor specific, do we need it? 538 section_headers[SH_DYNAMIC].sh_name = shstrtab_dynamic_offset; 539 section_headers[SH_DYNAMIC].sh_type = llvm::ELF::SHT_DYNAMIC; 540 section_headers[SH_DYNAMIC].sh_flags = llvm::ELF::SHF_WRITE | llvm::ELF::SHF_ALLOC; 541 section_headers[SH_DYNAMIC].sh_addr = dynamic_offset; 542 section_headers[SH_DYNAMIC].sh_offset = dynamic_offset; 543 section_headers[SH_DYNAMIC].sh_size = dynamic_size; 544 section_headers[SH_DYNAMIC].sh_link = SH_DYNSTR; 545 section_headers[SH_DYNAMIC].sh_info = 0; 546 section_headers[SH_DYNAMIC].sh_addralign = dynamic_alignment; 547 section_headers[SH_DYNAMIC].sh_entsize = sizeof(llvm::ELF::Elf32_Dyn); 548 549 section_headers[SH_SHSTRTAB].sh_name = shstrtab_shstrtab_offset; 550 section_headers[SH_SHSTRTAB].sh_type = llvm::ELF::SHT_STRTAB; 551 section_headers[SH_SHSTRTAB].sh_flags = 0; 552 section_headers[SH_SHSTRTAB].sh_addr = shstrtab_offset; 553 section_headers[SH_SHSTRTAB].sh_offset = shstrtab_offset; 554 section_headers[SH_SHSTRTAB].sh_size = shstrtab_size; 555 section_headers[SH_SHSTRTAB].sh_link = 0; 556 section_headers[SH_SHSTRTAB].sh_info = 0; 557 section_headers[SH_SHSTRTAB].sh_addralign = shstrtab_alignment; 558 section_headers[SH_SHSTRTAB].sh_entsize = 0; 559 560 // phase 3: writing file 561 562 // Elf32_Ehdr 563 if (!elf_file_->WriteFully(&elf_header, sizeof(elf_header))) { 564 PLOG(ERROR) << "Failed to write ELF header for " << elf_file_->GetPath(); 565 return false; 566 } 567 568 // PHDR 569 if (static_cast<off_t>(phdr_offset) != lseek(elf_file_->Fd(), 0, SEEK_CUR)) { 570 PLOG(ERROR) << "Failed to be at expected ELF program header offset phdr_offset " 571 << " for " << elf_file_->GetPath(); 572 return false; 573 } 574 if (!elf_file_->WriteFully(program_headers, sizeof(program_headers))) { 575 PLOG(ERROR) << "Failed to write ELF program headers for " << elf_file_->GetPath(); 576 return false; 577 } 578 579 // .dynsym 580 DCHECK_LE(phdr_offset + phdr_size, dynsym_offset); 581 if (static_cast<off_t>(dynsym_offset) != lseek(elf_file_->Fd(), dynsym_offset, SEEK_SET)) { 582 PLOG(ERROR) << "Failed to seek to .dynsym offset location " << dynsym_offset 583 << " for " << elf_file_->GetPath(); 584 return false; 585 } 586 if (!elf_file_->WriteFully(dynsym, sizeof(dynsym))) { 587 PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath(); 588 return false; 589 } 590 591 // .dynstr 592 DCHECK_LE(dynsym_offset + dynsym_size, dynstr_offset); 593 if (static_cast<off_t>(dynstr_offset) != lseek(elf_file_->Fd(), dynstr_offset, SEEK_SET)) { 594 PLOG(ERROR) << "Failed to seek to .dynstr offset " << dynstr_offset 595 << " for " << elf_file_->GetPath(); 596 return false; 597 } 598 if (!elf_file_->WriteFully(&dynstr[0], dynsym_size)) { 599 PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath(); 600 return false; 601 } 602 603 // .hash 604 DCHECK_LE(dynstr_offset + dynstr_size, hash_offset); 605 if (static_cast<off_t>(hash_offset) != lseek(elf_file_->Fd(), hash_offset, SEEK_SET)) { 606 PLOG(ERROR) << "Failed to seek to .hash offset " << hash_offset 607 << " for " << elf_file_->GetPath(); 608 return false; 609 } 610 if (!elf_file_->WriteFully(hash, sizeof(hash))) { 611 PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath(); 612 return false; 613 } 614 615 // .rodata .text 616 DCHECK_LE(hash_offset + hash_size, oat_data_offset); 617 if (static_cast<off_t>(oat_data_offset) != lseek(elf_file_->Fd(), oat_data_offset, SEEK_SET)) { 618 PLOG(ERROR) << "Failed to seek to .rodata offset " << oat_data_offset 619 << " for " << elf_file_->GetPath(); 620 return false; 621 } 622 FileOutputStream output_stream(elf_file_); 623 if (!oat_writer.Write(output_stream)) { 624 PLOG(ERROR) << "Failed to write .rodata and .text for " << elf_file_->GetPath(); 625 return false; 626 } 627 628 // .dynamic 629 DCHECK_LE(oat_data_offset + oat_writer.GetSize(), dynamic_offset); 630 if (static_cast<off_t>(dynamic_offset) != lseek(elf_file_->Fd(), dynamic_offset, SEEK_SET)) { 631 PLOG(ERROR) << "Failed to seek to .dynamic offset " << dynamic_offset 632 << " for " << elf_file_->GetPath(); 633 return false; 634 } 635 if (!elf_file_->WriteFully(&dynamic_headers[0], dynamic_size)) { 636 PLOG(ERROR) << "Failed to write .dynamic for " << elf_file_->GetPath(); 637 return false; 638 } 639 640 // .shstrtab 641 DCHECK_LE(dynamic_offset + dynamic_size, shstrtab_offset); 642 if (static_cast<off_t>(shstrtab_offset) != lseek(elf_file_->Fd(), shstrtab_offset, SEEK_SET)) { 643 PLOG(ERROR) << "Failed to seek to .shstrtab offset " << shstrtab_offset 644 << " for " << elf_file_->GetPath(); 645 return false; 646 } 647 if (!elf_file_->WriteFully(&shstrtab[0], shstrtab_size)) { 648 PLOG(ERROR) << "Failed to write .shstrtab for " << elf_file_->GetPath(); 649 return false; 650 } 651 652 // section headers (after all sections) 653 DCHECK_LE(shstrtab_offset + shstrtab_size, shdr_offset); 654 if (static_cast<off_t>(shdr_offset) != lseek(elf_file_->Fd(), shdr_offset, SEEK_SET)) { 655 PLOG(ERROR) << "Failed to seek to ELF section headers offset " << shdr_offset 656 << " for " << elf_file_->GetPath(); 657 return false; 658 } 659 if (!elf_file_->WriteFully(section_headers, sizeof(section_headers))) { 660 PLOG(ERROR) << "Failed to write ELF section headers for " << elf_file_->GetPath(); 661 return false; 662 } 663 664 VLOG(compiler) << "ELF file written successfully: " << elf_file_->GetPath(); 665 return true; 666} 667 668} // namespace art 669