github.com/euank/go@v0.0.0-20160829210321-495514729181/src/cmd/link/internal/ld/elf.go (about) 1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package ld 6 7 import ( 8 "cmd/internal/obj" 9 "cmd/internal/sys" 10 "crypto/sha1" 11 "encoding/binary" 12 "encoding/hex" 13 "path/filepath" 14 "sort" 15 "strings" 16 ) 17 18 /* 19 * Derived from: 20 * $FreeBSD: src/sys/sys/elf32.h,v 1.8.14.1 2005/12/30 22:13:58 marcel Exp $ 21 * $FreeBSD: src/sys/sys/elf64.h,v 1.10.14.1 2005/12/30 22:13:58 marcel Exp $ 22 * $FreeBSD: src/sys/sys/elf_common.h,v 1.15.8.1 2005/12/30 22:13:58 marcel Exp $ 23 * $FreeBSD: src/sys/alpha/include/elf.h,v 1.14 2003/09/25 01:10:22 peter Exp $ 24 * $FreeBSD: src/sys/amd64/include/elf.h,v 1.18 2004/08/03 08:21:48 dfr Exp $ 25 * $FreeBSD: src/sys/arm/include/elf.h,v 1.5.2.1 2006/06/30 21:42:52 cognet Exp $ 26 * $FreeBSD: src/sys/i386/include/elf.h,v 1.16 2004/08/02 19:12:17 dfr Exp $ 27 * $FreeBSD: src/sys/powerpc/include/elf.h,v 1.7 2004/11/02 09:47:01 ssouhlal Exp $ 28 * $FreeBSD: src/sys/sparc64/include/elf.h,v 1.12 2003/09/25 01:10:26 peter Exp $ 29 * 30 * Copyright (c) 1996-1998 John D. Polstra. All rights reserved. 31 * Copyright (c) 2001 David E. O'Brien 32 * Portions Copyright 2009 The Go Authors. All rights reserved. 33 * 34 * Redistribution and use in source and binary forms, with or without 35 * modification, are permitted provided that the following conditions 36 * are met: 37 * 1. Redistributions of source code must retain the above copyright 38 * notice, this list of conditions and the following disclaimer. 39 * 2. Redistributions in binary form must reproduce the above copyright 40 * notice, this list of conditions and the following disclaimer in the 41 * documentation and/or other materials provided with the distribution. 42 * 43 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 44 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 45 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 46 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 47 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 48 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 49 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 50 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 51 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 52 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 53 * SUCH DAMAGE. 54 * 55 */ 56 57 /* 58 * ELF definitions that are independent of architecture or word size. 59 */ 60 61 /* 62 * Note header. The ".note" section contains an array of notes. Each 63 * begins with this header, aligned to a word boundary. Immediately 64 * following the note header is n_namesz bytes of name, padded to the 65 * next word boundary. Then comes n_descsz bytes of descriptor, again 66 * padded to a word boundary. The values of n_namesz and n_descsz do 67 * not include the padding. 68 */ 69 type elfNote struct { 70 nNamesz uint32 71 nDescsz uint32 72 nType uint32 73 } 74 75 const ( 76 EI_MAG0 = 0 77 EI_MAG1 = 1 78 EI_MAG2 = 2 79 EI_MAG3 = 3 80 EI_CLASS = 4 81 EI_DATA = 5 82 EI_VERSION = 6 83 EI_OSABI = 7 84 EI_ABIVERSION = 8 85 OLD_EI_BRAND = 8 86 EI_PAD = 9 87 EI_NIDENT = 16 88 ELFMAG0 = 0x7f 89 ELFMAG1 = 'E' 90 ELFMAG2 = 'L' 91 ELFMAG3 = 'F' 92 SELFMAG = 4 93 EV_NONE = 0 94 EV_CURRENT = 1 95 ELFCLASSNONE = 0 96 ELFCLASS32 = 1 97 ELFCLASS64 = 2 98 ELFDATANONE = 0 99 ELFDATA2LSB = 1 100 ELFDATA2MSB = 2 101 ELFOSABI_NONE = 0 102 ELFOSABI_HPUX = 1 103 ELFOSABI_NETBSD = 2 104 ELFOSABI_LINUX = 3 105 ELFOSABI_HURD = 4 106 ELFOSABI_86OPEN = 5 107 ELFOSABI_SOLARIS = 6 108 ELFOSABI_AIX = 7 109 ELFOSABI_IRIX = 8 110 ELFOSABI_FREEBSD = 9 111 ELFOSABI_TRU64 = 10 112 ELFOSABI_MODESTO = 11 113 ELFOSABI_OPENBSD = 12 114 ELFOSABI_OPENVMS = 13 115 ELFOSABI_NSK = 14 116 ELFOSABI_ARM = 97 117 ELFOSABI_STANDALONE = 255 118 ELFOSABI_SYSV = ELFOSABI_NONE 119 ELFOSABI_MONTEREY = ELFOSABI_AIX 120 ET_NONE = 0 121 ET_REL = 1 122 ET_EXEC = 2 123 ET_DYN = 3 124 ET_CORE = 4 125 ET_LOOS = 0xfe00 126 ET_HIOS = 0xfeff 127 ET_LOPROC = 0xff00 128 ET_HIPROC = 0xffff 129 EM_NONE = 0 130 EM_M32 = 1 131 EM_SPARC = 2 132 EM_386 = 3 133 EM_68K = 4 134 EM_88K = 5 135 EM_860 = 7 136 EM_MIPS = 8 137 EM_S370 = 9 138 EM_MIPS_RS3_LE = 10 139 EM_PARISC = 15 140 EM_VPP500 = 17 141 EM_SPARC32PLUS = 18 142 EM_960 = 19 143 EM_PPC = 20 144 EM_PPC64 = 21 145 EM_S390 = 22 146 EM_V800 = 36 147 EM_FR20 = 37 148 EM_RH32 = 38 149 EM_RCE = 39 150 EM_ARM = 40 151 EM_SH = 42 152 EM_SPARCV9 = 43 153 EM_TRICORE = 44 154 EM_ARC = 45 155 EM_H8_300 = 46 156 EM_H8_300H = 47 157 EM_H8S = 48 158 EM_H8_500 = 49 159 EM_IA_64 = 50 160 EM_MIPS_X = 51 161 EM_COLDFIRE = 52 162 EM_68HC12 = 53 163 EM_MMA = 54 164 EM_PCP = 55 165 EM_NCPU = 56 166 EM_NDR1 = 57 167 EM_STARCORE = 58 168 EM_ME16 = 59 169 EM_ST100 = 60 170 EM_TINYJ = 61 171 EM_X86_64 = 62 172 EM_AARCH64 = 183 173 EM_486 = 6 174 EM_MIPS_RS4_BE = 10 175 EM_ALPHA_STD = 41 176 EM_ALPHA = 0x9026 177 SHN_UNDEF = 0 178 SHN_LORESERVE = 0xff00 179 SHN_LOPROC = 0xff00 180 SHN_HIPROC = 0xff1f 181 SHN_LOOS = 0xff20 182 SHN_HIOS = 0xff3f 183 SHN_ABS = 0xfff1 184 SHN_COMMON = 0xfff2 185 SHN_XINDEX = 0xffff 186 SHN_HIRESERVE = 0xffff 187 SHT_NULL = 0 188 SHT_PROGBITS = 1 189 SHT_SYMTAB = 2 190 SHT_STRTAB = 3 191 SHT_RELA = 4 192 SHT_HASH = 5 193 SHT_DYNAMIC = 6 194 SHT_NOTE = 7 195 SHT_NOBITS = 8 196 SHT_REL = 9 197 SHT_SHLIB = 10 198 SHT_DYNSYM = 11 199 SHT_INIT_ARRAY = 14 200 SHT_FINI_ARRAY = 15 201 SHT_PREINIT_ARRAY = 16 202 SHT_GROUP = 17 203 SHT_SYMTAB_SHNDX = 18 204 SHT_LOOS = 0x60000000 205 SHT_HIOS = 0x6fffffff 206 SHT_GNU_VERDEF = 0x6ffffffd 207 SHT_GNU_VERNEED = 0x6ffffffe 208 SHT_GNU_VERSYM = 0x6fffffff 209 SHT_LOPROC = 0x70000000 210 SHT_ARM_ATTRIBUTES = 0x70000003 211 SHT_HIPROC = 0x7fffffff 212 SHT_LOUSER = 0x80000000 213 SHT_HIUSER = 0xffffffff 214 SHF_WRITE = 0x1 215 SHF_ALLOC = 0x2 216 SHF_EXECINSTR = 0x4 217 SHF_MERGE = 0x10 218 SHF_STRINGS = 0x20 219 SHF_INFO_LINK = 0x40 220 SHF_LINK_ORDER = 0x80 221 SHF_OS_NONCONFORMING = 0x100 222 SHF_GROUP = 0x200 223 SHF_TLS = 0x400 224 SHF_MASKOS = 0x0ff00000 225 SHF_MASKPROC = 0xf0000000 226 PT_NULL = 0 227 PT_LOAD = 1 228 PT_DYNAMIC = 2 229 PT_INTERP = 3 230 PT_NOTE = 4 231 PT_SHLIB = 5 232 PT_PHDR = 6 233 PT_TLS = 7 234 PT_LOOS = 0x60000000 235 PT_HIOS = 0x6fffffff 236 PT_LOPROC = 0x70000000 237 PT_HIPROC = 0x7fffffff 238 PT_GNU_STACK = 0x6474e551 239 PT_PAX_FLAGS = 0x65041580 240 PF_X = 0x1 241 PF_W = 0x2 242 PF_R = 0x4 243 PF_MASKOS = 0x0ff00000 244 PF_MASKPROC = 0xf0000000 245 DT_NULL = 0 246 DT_NEEDED = 1 247 DT_PLTRELSZ = 2 248 DT_PLTGOT = 3 249 DT_HASH = 4 250 DT_STRTAB = 5 251 DT_SYMTAB = 6 252 DT_RELA = 7 253 DT_RELASZ = 8 254 DT_RELAENT = 9 255 DT_STRSZ = 10 256 DT_SYMENT = 11 257 DT_INIT = 12 258 DT_FINI = 13 259 DT_SONAME = 14 260 DT_RPATH = 15 261 DT_SYMBOLIC = 16 262 DT_REL = 17 263 DT_RELSZ = 18 264 DT_RELENT = 19 265 DT_PLTREL = 20 266 DT_DEBUG = 21 267 DT_TEXTREL = 22 268 DT_JMPREL = 23 269 DT_BIND_NOW = 24 270 DT_INIT_ARRAY = 25 271 DT_FINI_ARRAY = 26 272 DT_INIT_ARRAYSZ = 27 273 DT_FINI_ARRAYSZ = 28 274 DT_RUNPATH = 29 275 DT_FLAGS = 30 276 DT_ENCODING = 32 277 DT_PREINIT_ARRAY = 32 278 DT_PREINIT_ARRAYSZ = 33 279 DT_LOOS = 0x6000000d 280 DT_HIOS = 0x6ffff000 281 DT_LOPROC = 0x70000000 282 DT_HIPROC = 0x7fffffff 283 DT_VERNEED = 0x6ffffffe 284 DT_VERNEEDNUM = 0x6fffffff 285 DT_VERSYM = 0x6ffffff0 286 DT_PPC64_GLINK = DT_LOPROC + 0 287 DT_PPC64_OPT = DT_LOPROC + 3 288 DF_ORIGIN = 0x0001 289 DF_SYMBOLIC = 0x0002 290 DF_TEXTREL = 0x0004 291 DF_BIND_NOW = 0x0008 292 DF_STATIC_TLS = 0x0010 293 NT_PRSTATUS = 1 294 NT_FPREGSET = 2 295 NT_PRPSINFO = 3 296 STB_LOCAL = 0 297 STB_GLOBAL = 1 298 STB_WEAK = 2 299 STB_LOOS = 10 300 STB_HIOS = 12 301 STB_LOPROC = 13 302 STB_HIPROC = 15 303 STT_NOTYPE = 0 304 STT_OBJECT = 1 305 STT_FUNC = 2 306 STT_SECTION = 3 307 STT_FILE = 4 308 STT_COMMON = 5 309 STT_TLS = 6 310 STT_LOOS = 10 311 STT_HIOS = 12 312 STT_LOPROC = 13 313 STT_HIPROC = 15 314 STV_DEFAULT = 0x0 315 STV_INTERNAL = 0x1 316 STV_HIDDEN = 0x2 317 STV_PROTECTED = 0x3 318 STN_UNDEF = 0 319 ) 320 321 /* For accessing the fields of r_info. */ 322 323 /* For constructing r_info from field values. */ 324 325 /* 326 * Relocation types. 327 */ 328 const ( 329 R_X86_64_NONE = 0 330 R_X86_64_64 = 1 331 R_X86_64_PC32 = 2 332 R_X86_64_GOT32 = 3 333 R_X86_64_PLT32 = 4 334 R_X86_64_COPY = 5 335 R_X86_64_GLOB_DAT = 6 336 R_X86_64_JMP_SLOT = 7 337 R_X86_64_RELATIVE = 8 338 R_X86_64_GOTPCREL = 9 339 R_X86_64_32 = 10 340 R_X86_64_32S = 11 341 R_X86_64_16 = 12 342 R_X86_64_PC16 = 13 343 R_X86_64_8 = 14 344 R_X86_64_PC8 = 15 345 R_X86_64_DTPMOD64 = 16 346 R_X86_64_DTPOFF64 = 17 347 R_X86_64_TPOFF64 = 18 348 R_X86_64_TLSGD = 19 349 R_X86_64_TLSLD = 20 350 R_X86_64_DTPOFF32 = 21 351 R_X86_64_GOTTPOFF = 22 352 R_X86_64_TPOFF32 = 23 353 R_X86_64_PC64 = 24 354 R_X86_64_GOTOFF64 = 25 355 R_X86_64_GOTPC32 = 26 356 R_X86_64_GOT64 = 27 357 R_X86_64_GOTPCREL64 = 28 358 R_X86_64_GOTPC64 = 29 359 R_X86_64_GOTPLT64 = 30 360 R_X86_64_PLTOFF64 = 31 361 R_X86_64_SIZE32 = 32 362 R_X86_64_SIZE64 = 33 363 R_X86_64_GOTPC32_TLSDEC = 34 364 R_X86_64_TLSDESC_CALL = 35 365 R_X86_64_TLSDESC = 36 366 R_X86_64_IRELATIVE = 37 367 R_X86_64_PC32_BND = 40 368 R_X86_64_GOTPCRELX = 41 369 R_X86_64_REX_GOTPCRELX = 42 370 371 R_AARCH64_ABS64 = 257 372 R_AARCH64_ABS32 = 258 373 R_AARCH64_CALL26 = 283 374 R_AARCH64_ADR_PREL_PG_HI21 = 275 375 R_AARCH64_ADD_ABS_LO12_NC = 277 376 R_AARCH64_LDST8_ABS_LO12_NC = 278 377 R_AARCH64_LDST16_ABS_LO12_NC = 284 378 R_AARCH64_LDST32_ABS_LO12_NC = 285 379 R_AARCH64_LDST64_ABS_LO12_NC = 286 380 R_AARCH64_ADR_GOT_PAGE = 311 381 R_AARCH64_LD64_GOT_LO12_NC = 312 382 R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 = 541 383 R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC = 542 384 R_AARCH64_TLSLE_MOVW_TPREL_G0 = 547 385 386 R_ALPHA_NONE = 0 387 R_ALPHA_REFLONG = 1 388 R_ALPHA_REFQUAD = 2 389 R_ALPHA_GPREL32 = 3 390 R_ALPHA_LITERAL = 4 391 R_ALPHA_LITUSE = 5 392 R_ALPHA_GPDISP = 6 393 R_ALPHA_BRADDR = 7 394 R_ALPHA_HINT = 8 395 R_ALPHA_SREL16 = 9 396 R_ALPHA_SREL32 = 10 397 R_ALPHA_SREL64 = 11 398 R_ALPHA_OP_PUSH = 12 399 R_ALPHA_OP_STORE = 13 400 R_ALPHA_OP_PSUB = 14 401 R_ALPHA_OP_PRSHIFT = 15 402 R_ALPHA_GPVALUE = 16 403 R_ALPHA_GPRELHIGH = 17 404 R_ALPHA_GPRELLOW = 18 405 R_ALPHA_IMMED_GP_16 = 19 406 R_ALPHA_IMMED_GP_HI32 = 20 407 R_ALPHA_IMMED_SCN_HI32 = 21 408 R_ALPHA_IMMED_BR_HI32 = 22 409 R_ALPHA_IMMED_LO32 = 23 410 R_ALPHA_COPY = 24 411 R_ALPHA_GLOB_DAT = 25 412 R_ALPHA_JMP_SLOT = 26 413 R_ALPHA_RELATIVE = 27 414 415 R_ARM_NONE = 0 416 R_ARM_PC24 = 1 417 R_ARM_ABS32 = 2 418 R_ARM_REL32 = 3 419 R_ARM_PC13 = 4 420 R_ARM_ABS16 = 5 421 R_ARM_ABS12 = 6 422 R_ARM_THM_ABS5 = 7 423 R_ARM_ABS8 = 8 424 R_ARM_SBREL32 = 9 425 R_ARM_THM_PC22 = 10 426 R_ARM_THM_PC8 = 11 427 R_ARM_AMP_VCALL9 = 12 428 R_ARM_SWI24 = 13 429 R_ARM_THM_SWI8 = 14 430 R_ARM_XPC25 = 15 431 R_ARM_THM_XPC22 = 16 432 R_ARM_COPY = 20 433 R_ARM_GLOB_DAT = 21 434 R_ARM_JUMP_SLOT = 22 435 R_ARM_RELATIVE = 23 436 R_ARM_GOTOFF = 24 437 R_ARM_GOTPC = 25 438 R_ARM_GOT32 = 26 439 R_ARM_PLT32 = 27 440 R_ARM_CALL = 28 441 R_ARM_JUMP24 = 29 442 R_ARM_V4BX = 40 443 R_ARM_GOT_PREL = 96 444 R_ARM_GNU_VTENTRY = 100 445 R_ARM_GNU_VTINHERIT = 101 446 R_ARM_TLS_IE32 = 107 447 R_ARM_TLS_LE32 = 108 448 R_ARM_RSBREL32 = 250 449 R_ARM_THM_RPC22 = 251 450 R_ARM_RREL32 = 252 451 R_ARM_RABS32 = 253 452 R_ARM_RPC24 = 254 453 R_ARM_RBASE = 255 454 455 R_386_NONE = 0 456 R_386_32 = 1 457 R_386_PC32 = 2 458 R_386_GOT32 = 3 459 R_386_PLT32 = 4 460 R_386_COPY = 5 461 R_386_GLOB_DAT = 6 462 R_386_JMP_SLOT = 7 463 R_386_RELATIVE = 8 464 R_386_GOTOFF = 9 465 R_386_GOTPC = 10 466 R_386_TLS_TPOFF = 14 467 R_386_TLS_IE = 15 468 R_386_TLS_GOTIE = 16 469 R_386_TLS_LE = 17 470 R_386_TLS_GD = 18 471 R_386_TLS_LDM = 19 472 R_386_TLS_GD_32 = 24 473 R_386_TLS_GD_PUSH = 25 474 R_386_TLS_GD_CALL = 26 475 R_386_TLS_GD_POP = 27 476 R_386_TLS_LDM_32 = 28 477 R_386_TLS_LDM_PUSH = 29 478 R_386_TLS_LDM_CALL = 30 479 R_386_TLS_LDM_POP = 31 480 R_386_TLS_LDO_32 = 32 481 R_386_TLS_IE_32 = 33 482 R_386_TLS_LE_32 = 34 483 R_386_TLS_DTPMOD32 = 35 484 R_386_TLS_DTPOFF32 = 36 485 R_386_TLS_TPOFF32 = 37 486 R_386_TLS_GOTDESC = 39 487 R_386_TLS_DESC_CALL = 40 488 R_386_TLS_DESC = 41 489 R_386_IRELATIVE = 42 490 R_386_GOT32X = 43 491 492 R_MIPS_NONE = 0 493 R_MIPS_16 = 1 494 R_MIPS_32 = 2 495 R_MIPS_REL32 = 3 496 R_MIPS_26 = 4 497 R_MIPS_HI16 = 5 498 R_MIPS_LO16 = 6 499 R_MIPS_GPREL16 = 7 500 R_MIPS_LITERAL = 8 501 R_MIPS_GOT16 = 9 502 R_MIPS_PC16 = 10 503 R_MIPS_CALL16 = 11 504 R_MIPS_GPREL32 = 12 505 R_MIPS_SHIFT5 = 16 506 R_MIPS_SHIFT6 = 17 507 R_MIPS_64 = 18 508 R_MIPS_GOT_DISP = 19 509 R_MIPS_GOT_PAGE = 20 510 R_MIPS_GOT_OFST = 21 511 R_MIPS_GOT_HI16 = 22 512 R_MIPS_GOT_LO16 = 23 513 R_MIPS_SUB = 24 514 R_MIPS_INSERT_A = 25 515 R_MIPS_INSERT_B = 26 516 R_MIPS_DELETE = 27 517 R_MIPS_HIGHER = 28 518 R_MIPS_HIGHEST = 29 519 R_MIPS_CALL_HI16 = 30 520 R_MIPS_CALL_LO16 = 31 521 R_MIPS_SCN_DISP = 32 522 R_MIPS_REL16 = 33 523 R_MIPS_ADD_IMMEDIATE = 34 524 R_MIPS_PJUMP = 35 525 R_MIPS_RELGOT = 36 526 R_MIPS_JALR = 37 527 R_MIPS_TLS_DTPMOD32 = 38 528 R_MIPS_TLS_DTPREL32 = 39 529 R_MIPS_TLS_DTPMOD64 = 40 530 R_MIPS_TLS_DTPREL64 = 41 531 R_MIPS_TLS_GD = 42 532 R_MIPS_TLS_LDM = 43 533 R_MIPS_TLS_DTPREL_HI16 = 44 534 R_MIPS_TLS_DTPREL_LO16 = 45 535 R_MIPS_TLS_GOTTPREL = 46 536 R_MIPS_TLS_TPREL32 = 47 537 R_MIPS_TLS_TPREL64 = 48 538 R_MIPS_TLS_TPREL_HI16 = 49 539 R_MIPS_TLS_TPREL_LO16 = 50 540 541 R_PPC_NONE = 0 542 R_PPC_ADDR32 = 1 543 R_PPC_ADDR24 = 2 544 R_PPC_ADDR16 = 3 545 R_PPC_ADDR16_LO = 4 546 R_PPC_ADDR16_HI = 5 547 R_PPC_ADDR16_HA = 6 548 R_PPC_ADDR14 = 7 549 R_PPC_ADDR14_BRTAKEN = 8 550 R_PPC_ADDR14_BRNTAKEN = 9 551 R_PPC_REL24 = 10 552 R_PPC_REL14 = 11 553 R_PPC_REL14_BRTAKEN = 12 554 R_PPC_REL14_BRNTAKEN = 13 555 R_PPC_GOT16 = 14 556 R_PPC_GOT16_LO = 15 557 R_PPC_GOT16_HI = 16 558 R_PPC_GOT16_HA = 17 559 R_PPC_PLTREL24 = 18 560 R_PPC_COPY = 19 561 R_PPC_GLOB_DAT = 20 562 R_PPC_JMP_SLOT = 21 563 R_PPC_RELATIVE = 22 564 R_PPC_LOCAL24PC = 23 565 R_PPC_UADDR32 = 24 566 R_PPC_UADDR16 = 25 567 R_PPC_REL32 = 26 568 R_PPC_PLT32 = 27 569 R_PPC_PLTREL32 = 28 570 R_PPC_PLT16_LO = 29 571 R_PPC_PLT16_HI = 30 572 R_PPC_PLT16_HA = 31 573 R_PPC_SDAREL16 = 32 574 R_PPC_SECTOFF = 33 575 R_PPC_SECTOFF_LO = 34 576 R_PPC_SECTOFF_HI = 35 577 R_PPC_SECTOFF_HA = 36 578 R_PPC_TLS = 67 579 R_PPC_DTPMOD32 = 68 580 R_PPC_TPREL16 = 69 581 R_PPC_TPREL16_LO = 70 582 R_PPC_TPREL16_HI = 71 583 R_PPC_TPREL16_HA = 72 584 R_PPC_TPREL32 = 73 585 R_PPC_DTPREL16 = 74 586 R_PPC_DTPREL16_LO = 75 587 R_PPC_DTPREL16_HI = 76 588 R_PPC_DTPREL16_HA = 77 589 R_PPC_DTPREL32 = 78 590 R_PPC_GOT_TLSGD16 = 79 591 R_PPC_GOT_TLSGD16_LO = 80 592 R_PPC_GOT_TLSGD16_HI = 81 593 R_PPC_GOT_TLSGD16_HA = 82 594 R_PPC_GOT_TLSLD16 = 83 595 R_PPC_GOT_TLSLD16_LO = 84 596 R_PPC_GOT_TLSLD16_HI = 85 597 R_PPC_GOT_TLSLD16_HA = 86 598 R_PPC_GOT_TPREL16 = 87 599 R_PPC_GOT_TPREL16_LO = 88 600 R_PPC_GOT_TPREL16_HI = 89 601 R_PPC_GOT_TPREL16_HA = 90 602 R_PPC_EMB_NADDR32 = 101 603 R_PPC_EMB_NADDR16 = 102 604 R_PPC_EMB_NADDR16_LO = 103 605 R_PPC_EMB_NADDR16_HI = 104 606 R_PPC_EMB_NADDR16_HA = 105 607 R_PPC_EMB_SDAI16 = 106 608 R_PPC_EMB_SDA2I16 = 107 609 R_PPC_EMB_SDA2REL = 108 610 R_PPC_EMB_SDA21 = 109 611 R_PPC_EMB_MRKREF = 110 612 R_PPC_EMB_RELSEC16 = 111 613 R_PPC_EMB_RELST_LO = 112 614 R_PPC_EMB_RELST_HI = 113 615 R_PPC_EMB_RELST_HA = 114 616 R_PPC_EMB_BIT_FLD = 115 617 R_PPC_EMB_RELSDA = 116 618 619 R_PPC64_ADDR32 = R_PPC_ADDR32 620 R_PPC64_ADDR16_LO = R_PPC_ADDR16_LO 621 R_PPC64_ADDR16_HA = R_PPC_ADDR16_HA 622 R_PPC64_REL24 = R_PPC_REL24 623 R_PPC64_GOT16_HA = R_PPC_GOT16_HA 624 R_PPC64_JMP_SLOT = R_PPC_JMP_SLOT 625 R_PPC64_TPREL16 = R_PPC_TPREL16 626 R_PPC64_ADDR64 = 38 627 R_PPC64_TOC16 = 47 628 R_PPC64_TOC16_LO = 48 629 R_PPC64_TOC16_HI = 49 630 R_PPC64_TOC16_HA = 50 631 R_PPC64_ADDR16_LO_DS = 57 632 R_PPC64_GOT16_LO_DS = 59 633 R_PPC64_TOC16_DS = 63 634 R_PPC64_TOC16_LO_DS = 64 635 R_PPC64_TLS = 67 636 R_PPC64_GOT_TPREL16_LO_DS = 88 637 R_PPC64_GOT_TPREL16_HA = 90 638 R_PPC64_REL16_LO = 250 639 R_PPC64_REL16_HI = 251 640 R_PPC64_REL16_HA = 252 641 642 R_SPARC_NONE = 0 643 R_SPARC_8 = 1 644 R_SPARC_16 = 2 645 R_SPARC_32 = 3 646 R_SPARC_DISP8 = 4 647 R_SPARC_DISP16 = 5 648 R_SPARC_DISP32 = 6 649 R_SPARC_WDISP30 = 7 650 R_SPARC_WDISP22 = 8 651 R_SPARC_HI22 = 9 652 R_SPARC_22 = 10 653 R_SPARC_13 = 11 654 R_SPARC_LO10 = 12 655 R_SPARC_GOT10 = 13 656 R_SPARC_GOT13 = 14 657 R_SPARC_GOT22 = 15 658 R_SPARC_PC10 = 16 659 R_SPARC_PC22 = 17 660 R_SPARC_WPLT30 = 18 661 R_SPARC_COPY = 19 662 R_SPARC_GLOB_DAT = 20 663 R_SPARC_JMP_SLOT = 21 664 R_SPARC_RELATIVE = 22 665 R_SPARC_UA32 = 23 666 R_SPARC_PLT32 = 24 667 R_SPARC_HIPLT22 = 25 668 R_SPARC_LOPLT10 = 26 669 R_SPARC_PCPLT32 = 27 670 R_SPARC_PCPLT22 = 28 671 R_SPARC_PCPLT10 = 29 672 R_SPARC_10 = 30 673 R_SPARC_11 = 31 674 R_SPARC_64 = 32 675 R_SPARC_OLO10 = 33 676 R_SPARC_HH22 = 34 677 R_SPARC_HM10 = 35 678 R_SPARC_LM22 = 36 679 R_SPARC_PC_HH22 = 37 680 R_SPARC_PC_HM10 = 38 681 R_SPARC_PC_LM22 = 39 682 R_SPARC_WDISP16 = 40 683 R_SPARC_WDISP19 = 41 684 R_SPARC_GLOB_JMP = 42 685 R_SPARC_7 = 43 686 R_SPARC_5 = 44 687 R_SPARC_6 = 45 688 R_SPARC_DISP64 = 46 689 R_SPARC_PLT64 = 47 690 R_SPARC_HIX22 = 48 691 R_SPARC_LOX10 = 49 692 R_SPARC_H44 = 50 693 R_SPARC_M44 = 51 694 R_SPARC_L44 = 52 695 R_SPARC_REGISTER = 53 696 R_SPARC_UA64 = 54 697 R_SPARC_UA16 = 55 698 699 R_390_NONE = 0 700 R_390_8 = 1 701 R_390_12 = 2 702 R_390_16 = 3 703 R_390_32 = 4 704 R_390_PC32 = 5 705 R_390_GOT12 = 6 706 R_390_GOT32 = 7 707 R_390_PLT32 = 8 708 R_390_COPY = 9 709 R_390_GLOB_DAT = 10 710 R_390_JMP_SLOT = 11 711 R_390_RELATIVE = 12 712 R_390_GOTOFF = 13 713 R_390_GOTPC = 14 714 R_390_GOT16 = 15 715 R_390_PC16 = 16 716 R_390_PC16DBL = 17 717 R_390_PLT16DBL = 18 718 R_390_PC32DBL = 19 719 R_390_PLT32DBL = 20 720 R_390_GOTPCDBL = 21 721 R_390_64 = 22 722 R_390_PC64 = 23 723 R_390_GOT64 = 24 724 R_390_PLT64 = 25 725 R_390_GOTENT = 26 726 R_390_GOTOFF16 = 27 727 R_390_GOTOFF64 = 28 728 R_390_GOTPLT12 = 29 729 R_390_GOTPLT16 = 30 730 R_390_GOTPLT32 = 31 731 R_390_GOTPLT64 = 32 732 R_390_GOTPLTENT = 33 733 R_390_GOTPLTOFF16 = 34 734 R_390_GOTPLTOFF32 = 35 735 R_390_GOTPLTOFF64 = 36 736 R_390_TLS_LOAD = 37 737 R_390_TLS_GDCALL = 38 738 R_390_TLS_LDCALL = 39 739 R_390_TLS_GD32 = 40 740 R_390_TLS_GD64 = 41 741 R_390_TLS_GOTIE12 = 42 742 R_390_TLS_GOTIE32 = 43 743 R_390_TLS_GOTIE64 = 44 744 R_390_TLS_LDM32 = 45 745 R_390_TLS_LDM64 = 46 746 R_390_TLS_IE32 = 47 747 R_390_TLS_IE64 = 48 748 R_390_TLS_IEENT = 49 749 R_390_TLS_LE32 = 50 750 R_390_TLS_LE64 = 51 751 R_390_TLS_LDO32 = 52 752 R_390_TLS_LDO64 = 53 753 R_390_TLS_DTPMOD = 54 754 R_390_TLS_DTPOFF = 55 755 R_390_TLS_TPOFF = 56 756 R_390_20 = 57 757 R_390_GOT20 = 58 758 R_390_GOTPLT20 = 59 759 R_390_TLS_GOTIE20 = 60 760 761 ARM_MAGIC_TRAMP_NUMBER = 0x5c000003 762 ) 763 764 /* 765 * Symbol table entries. 766 */ 767 768 /* For accessing the fields of st_info. */ 769 770 /* For constructing st_info from field values. */ 771 772 /* For accessing the fields of st_other. */ 773 774 /* 775 * ELF header. 776 */ 777 type ElfEhdr struct { 778 ident [EI_NIDENT]uint8 779 type_ uint16 780 machine uint16 781 version uint32 782 entry uint64 783 phoff uint64 784 shoff uint64 785 flags uint32 786 ehsize uint16 787 phentsize uint16 788 phnum uint16 789 shentsize uint16 790 shnum uint16 791 shstrndx uint16 792 } 793 794 /* 795 * Section header. 796 */ 797 type ElfShdr struct { 798 name uint32 799 type_ uint32 800 flags uint64 801 addr uint64 802 off uint64 803 size uint64 804 link uint32 805 info uint32 806 addralign uint64 807 entsize uint64 808 shnum int 809 secsym *Symbol 810 } 811 812 /* 813 * Program header. 814 */ 815 type ElfPhdr struct { 816 type_ uint32 817 flags uint32 818 off uint64 819 vaddr uint64 820 paddr uint64 821 filesz uint64 822 memsz uint64 823 align uint64 824 } 825 826 /* For accessing the fields of r_info. */ 827 828 /* For constructing r_info from field values. */ 829 830 /* 831 * Symbol table entries. 832 */ 833 834 /* For accessing the fields of st_info. */ 835 836 /* For constructing st_info from field values. */ 837 838 /* For accessing the fields of st_other. */ 839 840 /* 841 * Go linker interface 842 */ 843 const ( 844 ELF64HDRSIZE = 64 845 ELF64PHDRSIZE = 56 846 ELF64SHDRSIZE = 64 847 ELF64RELSIZE = 16 848 ELF64RELASIZE = 24 849 ELF64SYMSIZE = 24 850 ELF32HDRSIZE = 52 851 ELF32PHDRSIZE = 32 852 ELF32SHDRSIZE = 40 853 ELF32SYMSIZE = 16 854 ELF32RELSIZE = 8 855 ) 856 857 /* 858 * The interface uses the 64-bit structures always, 859 * to avoid code duplication. The writers know how to 860 * marshal a 32-bit representation from the 64-bit structure. 861 */ 862 863 var Elfstrdat []byte 864 865 /* 866 * Total amount of space to reserve at the start of the file 867 * for Header, PHeaders, SHeaders, and interp. 868 * May waste some. 869 * On FreeBSD, cannot be larger than a page. 870 */ 871 const ( 872 ELFRESERVE = 4096 873 ) 874 875 /* 876 * We use the 64-bit data structures on both 32- and 64-bit machines 877 * in order to write the code just once. The 64-bit data structure is 878 * written in the 32-bit format on the 32-bit machines. 879 */ 880 const ( 881 NSECT = 48 882 ) 883 884 var ( 885 Iself bool 886 887 Nelfsym int = 1 888 889 elf64 bool 890 // Either ".rel" or ".rela" depending on which type of relocation the 891 // target platform uses. 892 elfRelType string 893 894 ehdr ElfEhdr 895 phdr [NSECT]*ElfPhdr 896 shdr [NSECT]*ElfShdr 897 898 interp string 899 ) 900 901 type Elfstring struct { 902 s string 903 off int 904 } 905 906 var elfstr [100]Elfstring 907 908 var nelfstr int 909 910 var buildinfo []byte 911 912 /* 913 Initialize the global variable that describes the ELF header. It will be updated as 914 we write section and prog headers. 915 */ 916 func Elfinit(ctxt *Link) { 917 Iself = true 918 919 if SysArch.InFamily(sys.AMD64, sys.ARM64, sys.MIPS64, sys.PPC64, sys.S390X) { 920 elfRelType = ".rela" 921 } else { 922 elfRelType = ".rel" 923 } 924 925 switch SysArch.Family { 926 // 64-bit architectures 927 case sys.PPC64, sys.S390X: 928 if ctxt.Arch.ByteOrder == binary.BigEndian { 929 ehdr.flags = 1 /* Version 1 ABI */ 930 } else { 931 ehdr.flags = 2 /* Version 2 ABI */ 932 } 933 fallthrough 934 case sys.AMD64, sys.ARM64, sys.MIPS64: 935 if SysArch.Family == sys.MIPS64 { 936 ehdr.flags = 0x20000000 /* MIPS 3 */ 937 } 938 elf64 = true 939 940 ehdr.phoff = ELF64HDRSIZE /* Must be be ELF64HDRSIZE: first PHdr must follow ELF header */ 941 ehdr.shoff = ELF64HDRSIZE /* Will move as we add PHeaders */ 942 ehdr.ehsize = ELF64HDRSIZE /* Must be ELF64HDRSIZE */ 943 ehdr.phentsize = ELF64PHDRSIZE /* Must be ELF64PHDRSIZE */ 944 ehdr.shentsize = ELF64SHDRSIZE /* Must be ELF64SHDRSIZE */ 945 946 // we use EABI on both linux/arm and freebsd/arm. 947 // 32-bit architectures 948 case sys.ARM: 949 // we use EABI on both linux/arm and freebsd/arm. 950 if HEADTYPE == obj.Hlinux || HEADTYPE == obj.Hfreebsd { 951 // We set a value here that makes no indication of which 952 // float ABI the object uses, because this is information 953 // used by the dynamic linker to compare executables and 954 // shared libraries -- so it only matters for cgo calls, and 955 // the information properly comes from the object files 956 // produced by the host C compiler. parseArmAttributes in 957 // ldelf.go reads that information and updates this field as 958 // appropriate. 959 ehdr.flags = 0x5000002 // has entry point, Version5 EABI 960 } 961 fallthrough 962 default: 963 ehdr.phoff = ELF32HDRSIZE 964 /* Must be be ELF32HDRSIZE: first PHdr must follow ELF header */ 965 ehdr.shoff = ELF32HDRSIZE /* Will move as we add PHeaders */ 966 ehdr.ehsize = ELF32HDRSIZE /* Must be ELF32HDRSIZE */ 967 ehdr.phentsize = ELF32PHDRSIZE /* Must be ELF32PHDRSIZE */ 968 ehdr.shentsize = ELF32SHDRSIZE /* Must be ELF32SHDRSIZE */ 969 } 970 } 971 972 // Make sure PT_LOAD is aligned properly and 973 // that there is no gap, 974 // correct ELF loaders will do this implicitly, 975 // but buggy ELF loaders like the one in some 976 // versions of QEMU and UPX won't. 977 func fixElfPhdr(e *ElfPhdr) { 978 frag := int(e.vaddr & (e.align - 1)) 979 980 e.off -= uint64(frag) 981 e.vaddr -= uint64(frag) 982 e.paddr -= uint64(frag) 983 e.filesz += uint64(frag) 984 e.memsz += uint64(frag) 985 } 986 987 func elf64phdr(e *ElfPhdr) { 988 if e.type_ == PT_LOAD { 989 fixElfPhdr(e) 990 } 991 992 Thearch.Lput(e.type_) 993 Thearch.Lput(e.flags) 994 Thearch.Vput(e.off) 995 Thearch.Vput(e.vaddr) 996 Thearch.Vput(e.paddr) 997 Thearch.Vput(e.filesz) 998 Thearch.Vput(e.memsz) 999 Thearch.Vput(e.align) 1000 } 1001 1002 func elf32phdr(e *ElfPhdr) { 1003 if e.type_ == PT_LOAD { 1004 fixElfPhdr(e) 1005 } 1006 1007 Thearch.Lput(e.type_) 1008 Thearch.Lput(uint32(e.off)) 1009 Thearch.Lput(uint32(e.vaddr)) 1010 Thearch.Lput(uint32(e.paddr)) 1011 Thearch.Lput(uint32(e.filesz)) 1012 Thearch.Lput(uint32(e.memsz)) 1013 Thearch.Lput(e.flags) 1014 Thearch.Lput(uint32(e.align)) 1015 } 1016 1017 func elf64shdr(e *ElfShdr) { 1018 Thearch.Lput(e.name) 1019 Thearch.Lput(e.type_) 1020 Thearch.Vput(e.flags) 1021 Thearch.Vput(e.addr) 1022 Thearch.Vput(e.off) 1023 Thearch.Vput(e.size) 1024 Thearch.Lput(e.link) 1025 Thearch.Lput(e.info) 1026 Thearch.Vput(e.addralign) 1027 Thearch.Vput(e.entsize) 1028 } 1029 1030 func elf32shdr(e *ElfShdr) { 1031 Thearch.Lput(e.name) 1032 Thearch.Lput(e.type_) 1033 Thearch.Lput(uint32(e.flags)) 1034 Thearch.Lput(uint32(e.addr)) 1035 Thearch.Lput(uint32(e.off)) 1036 Thearch.Lput(uint32(e.size)) 1037 Thearch.Lput(e.link) 1038 Thearch.Lput(e.info) 1039 Thearch.Lput(uint32(e.addralign)) 1040 Thearch.Lput(uint32(e.entsize)) 1041 } 1042 1043 func elfwriteshdrs() uint32 { 1044 if elf64 { 1045 for i := 0; i < int(ehdr.shnum); i++ { 1046 elf64shdr(shdr[i]) 1047 } 1048 return uint32(ehdr.shnum) * ELF64SHDRSIZE 1049 } 1050 1051 for i := 0; i < int(ehdr.shnum); i++ { 1052 elf32shdr(shdr[i]) 1053 } 1054 return uint32(ehdr.shnum) * ELF32SHDRSIZE 1055 } 1056 1057 func elfsetstring(ctxt *Link, s string, off int) { 1058 if nelfstr >= len(elfstr) { 1059 ctxt.Diag("too many elf strings") 1060 errorexit() 1061 } 1062 1063 elfstr[nelfstr].s = s 1064 elfstr[nelfstr].off = off 1065 nelfstr++ 1066 } 1067 1068 func elfwritephdrs() uint32 { 1069 if elf64 { 1070 for i := 0; i < int(ehdr.phnum); i++ { 1071 elf64phdr(phdr[i]) 1072 } 1073 return uint32(ehdr.phnum) * ELF64PHDRSIZE 1074 } 1075 1076 for i := 0; i < int(ehdr.phnum); i++ { 1077 elf32phdr(phdr[i]) 1078 } 1079 return uint32(ehdr.phnum) * ELF32PHDRSIZE 1080 } 1081 1082 func newElfPhdr(ctxt *Link) *ElfPhdr { 1083 e := new(ElfPhdr) 1084 if ehdr.phnum >= NSECT { 1085 ctxt.Diag("too many phdrs") 1086 } else { 1087 phdr[ehdr.phnum] = e 1088 ehdr.phnum++ 1089 } 1090 if elf64 { 1091 ehdr.shoff += ELF64PHDRSIZE 1092 } else { 1093 ehdr.shoff += ELF32PHDRSIZE 1094 } 1095 return e 1096 } 1097 1098 func newElfShdr(ctxt *Link, name int64) *ElfShdr { 1099 e := new(ElfShdr) 1100 e.name = uint32(name) 1101 e.shnum = int(ehdr.shnum) 1102 if ehdr.shnum >= NSECT { 1103 ctxt.Diag("too many shdrs") 1104 } else { 1105 shdr[ehdr.shnum] = e 1106 ehdr.shnum++ 1107 } 1108 1109 return e 1110 } 1111 1112 func getElfEhdr() *ElfEhdr { 1113 return &ehdr 1114 } 1115 1116 func elf64writehdr() uint32 { 1117 for i := 0; i < EI_NIDENT; i++ { 1118 Cput(ehdr.ident[i]) 1119 } 1120 Thearch.Wput(ehdr.type_) 1121 Thearch.Wput(ehdr.machine) 1122 Thearch.Lput(ehdr.version) 1123 Thearch.Vput(ehdr.entry) 1124 Thearch.Vput(ehdr.phoff) 1125 Thearch.Vput(ehdr.shoff) 1126 Thearch.Lput(ehdr.flags) 1127 Thearch.Wput(ehdr.ehsize) 1128 Thearch.Wput(ehdr.phentsize) 1129 Thearch.Wput(ehdr.phnum) 1130 Thearch.Wput(ehdr.shentsize) 1131 Thearch.Wput(ehdr.shnum) 1132 Thearch.Wput(ehdr.shstrndx) 1133 return ELF64HDRSIZE 1134 } 1135 1136 func elf32writehdr() uint32 { 1137 for i := 0; i < EI_NIDENT; i++ { 1138 Cput(ehdr.ident[i]) 1139 } 1140 Thearch.Wput(ehdr.type_) 1141 Thearch.Wput(ehdr.machine) 1142 Thearch.Lput(ehdr.version) 1143 Thearch.Lput(uint32(ehdr.entry)) 1144 Thearch.Lput(uint32(ehdr.phoff)) 1145 Thearch.Lput(uint32(ehdr.shoff)) 1146 Thearch.Lput(ehdr.flags) 1147 Thearch.Wput(ehdr.ehsize) 1148 Thearch.Wput(ehdr.phentsize) 1149 Thearch.Wput(ehdr.phnum) 1150 Thearch.Wput(ehdr.shentsize) 1151 Thearch.Wput(ehdr.shnum) 1152 Thearch.Wput(ehdr.shstrndx) 1153 return ELF32HDRSIZE 1154 } 1155 1156 func elfwritehdr() uint32 { 1157 if elf64 { 1158 return elf64writehdr() 1159 } 1160 return elf32writehdr() 1161 } 1162 1163 /* Taken directly from the definition document for ELF64 */ 1164 func elfhash(name string) uint32 { 1165 var h uint32 1166 for i := 0; i < len(name); i++ { 1167 h = (h << 4) + uint32(name[i]) 1168 if g := h & 0xf0000000; g != 0 { 1169 h ^= g >> 24 1170 } 1171 h &= 0x0fffffff 1172 } 1173 return h 1174 } 1175 1176 func Elfwritedynent(ctxt *Link, s *Symbol, tag int, val uint64) { 1177 if elf64 { 1178 Adduint64(ctxt, s, uint64(tag)) 1179 Adduint64(ctxt, s, val) 1180 } else { 1181 Adduint32(ctxt, s, uint32(tag)) 1182 Adduint32(ctxt, s, uint32(val)) 1183 } 1184 } 1185 1186 func elfwritedynentsym(ctxt *Link, s *Symbol, tag int, t *Symbol) { 1187 Elfwritedynentsymplus(ctxt, s, tag, t, 0) 1188 } 1189 1190 func Elfwritedynentsymplus(ctxt *Link, s *Symbol, tag int, t *Symbol, add int64) { 1191 if elf64 { 1192 Adduint64(ctxt, s, uint64(tag)) 1193 } else { 1194 Adduint32(ctxt, s, uint32(tag)) 1195 } 1196 Addaddrplus(ctxt, s, t, add) 1197 } 1198 1199 func elfwritedynentsymsize(ctxt *Link, s *Symbol, tag int, t *Symbol) { 1200 if elf64 { 1201 Adduint64(ctxt, s, uint64(tag)) 1202 } else { 1203 Adduint32(ctxt, s, uint32(tag)) 1204 } 1205 addsize(ctxt, s, t) 1206 } 1207 1208 func elfinterp(sh *ElfShdr, startva uint64, resoff uint64, p string) int { 1209 interp = p 1210 n := len(interp) + 1 1211 sh.addr = startva + resoff - uint64(n) 1212 sh.off = resoff - uint64(n) 1213 sh.size = uint64(n) 1214 1215 return n 1216 } 1217 1218 func elfwriteinterp(ctxt *Link) int { 1219 sh := elfshname(ctxt, ".interp") 1220 Cseek(int64(sh.off)) 1221 coutbuf.WriteString(interp) 1222 Cput(0) 1223 return int(sh.size) 1224 } 1225 1226 func elfnote(sh *ElfShdr, startva uint64, resoff uint64, sz int, alloc bool) int { 1227 n := 3*4 + uint64(sz) + resoff%4 1228 1229 sh.type_ = SHT_NOTE 1230 if alloc { 1231 sh.flags = SHF_ALLOC 1232 } 1233 sh.addralign = 4 1234 sh.addr = startva + resoff - n 1235 sh.off = resoff - n 1236 sh.size = n - resoff%4 1237 1238 return int(n) 1239 } 1240 1241 func elfwritenotehdr(ctxt *Link, str string, namesz uint32, descsz uint32, tag uint32) *ElfShdr { 1242 sh := elfshname(ctxt, str) 1243 1244 // Write Elf_Note header. 1245 Cseek(int64(sh.off)) 1246 1247 Thearch.Lput(namesz) 1248 Thearch.Lput(descsz) 1249 Thearch.Lput(tag) 1250 1251 return sh 1252 } 1253 1254 // NetBSD Signature (as per sys/exec_elf.h) 1255 const ( 1256 ELF_NOTE_NETBSD_NAMESZ = 7 1257 ELF_NOTE_NETBSD_DESCSZ = 4 1258 ELF_NOTE_NETBSD_TAG = 1 1259 ELF_NOTE_NETBSD_VERSION = 599000000 /* NetBSD 5.99 */ 1260 ) 1261 1262 var ELF_NOTE_NETBSD_NAME = []byte("NetBSD\x00") 1263 1264 func elfnetbsdsig(sh *ElfShdr, startva uint64, resoff uint64) int { 1265 n := int(Rnd(ELF_NOTE_NETBSD_NAMESZ, 4) + Rnd(ELF_NOTE_NETBSD_DESCSZ, 4)) 1266 return elfnote(sh, startva, resoff, n, true) 1267 } 1268 1269 func elfwritenetbsdsig(ctxt *Link) int { 1270 // Write Elf_Note header. 1271 sh := elfwritenotehdr(ctxt, ".note.netbsd.ident", ELF_NOTE_NETBSD_NAMESZ, ELF_NOTE_NETBSD_DESCSZ, ELF_NOTE_NETBSD_TAG) 1272 1273 if sh == nil { 1274 return 0 1275 } 1276 1277 // Followed by NetBSD string and version. 1278 Cwrite(ELF_NOTE_NETBSD_NAME) 1279 Cput(0) 1280 1281 Thearch.Lput(ELF_NOTE_NETBSD_VERSION) 1282 1283 return int(sh.size) 1284 } 1285 1286 // OpenBSD Signature 1287 const ( 1288 ELF_NOTE_OPENBSD_NAMESZ = 8 1289 ELF_NOTE_OPENBSD_DESCSZ = 4 1290 ELF_NOTE_OPENBSD_TAG = 1 1291 ELF_NOTE_OPENBSD_VERSION = 0 1292 ) 1293 1294 var ELF_NOTE_OPENBSD_NAME = []byte("OpenBSD\x00") 1295 1296 func elfopenbsdsig(sh *ElfShdr, startva uint64, resoff uint64) int { 1297 n := ELF_NOTE_OPENBSD_NAMESZ + ELF_NOTE_OPENBSD_DESCSZ 1298 return elfnote(sh, startva, resoff, n, true) 1299 } 1300 1301 func elfwriteopenbsdsig(ctxt *Link) int { 1302 // Write Elf_Note header. 1303 sh := elfwritenotehdr(ctxt, ".note.openbsd.ident", ELF_NOTE_OPENBSD_NAMESZ, ELF_NOTE_OPENBSD_DESCSZ, ELF_NOTE_OPENBSD_TAG) 1304 1305 if sh == nil { 1306 return 0 1307 } 1308 1309 // Followed by OpenBSD string and version. 1310 Cwrite(ELF_NOTE_OPENBSD_NAME) 1311 1312 Thearch.Lput(ELF_NOTE_OPENBSD_VERSION) 1313 1314 return int(sh.size) 1315 } 1316 1317 func addbuildinfo(val string) { 1318 if !strings.HasPrefix(val, "0x") { 1319 Exitf("-B argument must start with 0x: %s", val) 1320 } 1321 1322 ov := val 1323 val = val[2:] 1324 1325 const maxLen = 32 1326 if hex.DecodedLen(len(val)) > maxLen { 1327 Exitf("-B option too long (max %d digits): %s", maxLen, ov) 1328 } 1329 1330 b, err := hex.DecodeString(val) 1331 if err != nil { 1332 if err == hex.ErrLength { 1333 Exitf("-B argument must have even number of digits: %s", ov) 1334 } 1335 if inv, ok := err.(hex.InvalidByteError); ok { 1336 Exitf("-B argument contains invalid hex digit %c: %s", byte(inv), ov) 1337 } 1338 Exitf("-B argument contains invalid hex: %s", ov) 1339 } 1340 1341 buildinfo = b 1342 } 1343 1344 // Build info note 1345 const ( 1346 ELF_NOTE_BUILDINFO_NAMESZ = 4 1347 ELF_NOTE_BUILDINFO_TAG = 3 1348 ) 1349 1350 var ELF_NOTE_BUILDINFO_NAME = []byte("GNU\x00") 1351 1352 func elfbuildinfo(sh *ElfShdr, startva uint64, resoff uint64) int { 1353 n := int(ELF_NOTE_BUILDINFO_NAMESZ + Rnd(int64(len(buildinfo)), 4)) 1354 return elfnote(sh, startva, resoff, n, true) 1355 } 1356 1357 func elfgobuildid(sh *ElfShdr, startva uint64, resoff uint64) int { 1358 n := len(ELF_NOTE_GO_NAME) + int(Rnd(int64(len(*flagBuildid)), 4)) 1359 return elfnote(sh, startva, resoff, n, true) 1360 } 1361 1362 func elfwritebuildinfo(ctxt *Link) int { 1363 sh := elfwritenotehdr(ctxt, ".note.gnu.build-id", ELF_NOTE_BUILDINFO_NAMESZ, uint32(len(buildinfo)), ELF_NOTE_BUILDINFO_TAG) 1364 if sh == nil { 1365 return 0 1366 } 1367 1368 Cwrite(ELF_NOTE_BUILDINFO_NAME) 1369 Cwrite(buildinfo) 1370 var zero = make([]byte, 4) 1371 Cwrite(zero[:int(Rnd(int64(len(buildinfo)), 4)-int64(len(buildinfo)))]) 1372 1373 return int(sh.size) 1374 } 1375 1376 func elfwritegobuildid(ctxt *Link) int { 1377 sh := elfwritenotehdr(ctxt, ".note.go.buildid", uint32(len(ELF_NOTE_GO_NAME)), uint32(len(*flagBuildid)), ELF_NOTE_GOBUILDID_TAG) 1378 if sh == nil { 1379 return 0 1380 } 1381 1382 Cwrite(ELF_NOTE_GO_NAME) 1383 Cwrite([]byte(*flagBuildid)) 1384 var zero = make([]byte, 4) 1385 Cwrite(zero[:int(Rnd(int64(len(*flagBuildid)), 4)-int64(len(*flagBuildid)))]) 1386 1387 return int(sh.size) 1388 } 1389 1390 // Go specific notes 1391 const ( 1392 ELF_NOTE_GOPKGLIST_TAG = 1 1393 ELF_NOTE_GOABIHASH_TAG = 2 1394 ELF_NOTE_GODEPS_TAG = 3 1395 ELF_NOTE_GOBUILDID_TAG = 4 1396 ) 1397 1398 var ELF_NOTE_GO_NAME = []byte("Go\x00\x00") 1399 1400 var elfverneed int 1401 1402 type Elfaux struct { 1403 next *Elfaux 1404 num int 1405 vers string 1406 } 1407 1408 type Elflib struct { 1409 next *Elflib 1410 aux *Elfaux 1411 file string 1412 } 1413 1414 func addelflib(list **Elflib, file string, vers string) *Elfaux { 1415 var lib *Elflib 1416 1417 for lib = *list; lib != nil; lib = lib.next { 1418 if lib.file == file { 1419 goto havelib 1420 } 1421 } 1422 lib = new(Elflib) 1423 lib.next = *list 1424 lib.file = file 1425 *list = lib 1426 1427 havelib: 1428 for aux := lib.aux; aux != nil; aux = aux.next { 1429 if aux.vers == vers { 1430 return aux 1431 } 1432 } 1433 aux := new(Elfaux) 1434 aux.next = lib.aux 1435 aux.vers = vers 1436 lib.aux = aux 1437 1438 return aux 1439 } 1440 1441 func elfdynhash(ctxt *Link) { 1442 if !Iself { 1443 return 1444 } 1445 1446 nsym := Nelfsym 1447 s := Linklookup(ctxt, ".hash", 0) 1448 s.Type = obj.SELFROSECT 1449 s.Attr |= AttrReachable 1450 1451 i := nsym 1452 nbucket := 1 1453 for i > 0 { 1454 nbucket++ 1455 i >>= 1 1456 } 1457 1458 var needlib *Elflib 1459 need := make([]*Elfaux, nsym) 1460 chain := make([]uint32, nsym) 1461 buckets := make([]uint32, nbucket) 1462 1463 var b int 1464 for _, sy := range ctxt.Allsym { 1465 if sy.Dynid <= 0 { 1466 continue 1467 } 1468 1469 if sy.Dynimpvers != "" { 1470 need[sy.Dynid] = addelflib(&needlib, sy.Dynimplib, sy.Dynimpvers) 1471 } 1472 1473 name := sy.Extname 1474 hc := elfhash(name) 1475 1476 b = int(hc % uint32(nbucket)) 1477 chain[sy.Dynid] = buckets[b] 1478 buckets[b] = uint32(sy.Dynid) 1479 } 1480 1481 // s390x (ELF64) hash table entries are 8 bytes 1482 if SysArch.Family == sys.S390X { 1483 Adduint64(ctxt, s, uint64(nbucket)) 1484 Adduint64(ctxt, s, uint64(nsym)) 1485 for i := 0; i < nbucket; i++ { 1486 Adduint64(ctxt, s, uint64(buckets[i])) 1487 } 1488 for i := 0; i < nsym; i++ { 1489 Adduint64(ctxt, s, uint64(chain[i])) 1490 } 1491 } else { 1492 Adduint32(ctxt, s, uint32(nbucket)) 1493 Adduint32(ctxt, s, uint32(nsym)) 1494 for i := 0; i < nbucket; i++ { 1495 Adduint32(ctxt, s, buckets[i]) 1496 } 1497 for i := 0; i < nsym; i++ { 1498 Adduint32(ctxt, s, chain[i]) 1499 } 1500 } 1501 1502 // version symbols 1503 dynstr := Linklookup(ctxt, ".dynstr", 0) 1504 1505 s = Linklookup(ctxt, ".gnu.version_r", 0) 1506 i = 2 1507 nfile := 0 1508 var j int 1509 var x *Elfaux 1510 for l := needlib; l != nil; l = l.next { 1511 nfile++ 1512 1513 // header 1514 Adduint16(ctxt, s, 1) // table version 1515 j = 0 1516 for x = l.aux; x != nil; x = x.next { 1517 j++ 1518 } 1519 Adduint16(ctxt, s, uint16(j)) // aux count 1520 Adduint32(ctxt, s, uint32(Addstring(ctxt, dynstr, l.file))) // file string offset 1521 Adduint32(ctxt, s, 16) // offset from header to first aux 1522 if l.next != nil { 1523 Adduint32(ctxt, s, 16+uint32(j)*16) // offset from this header to next 1524 } else { 1525 Adduint32(ctxt, s, 0) 1526 } 1527 1528 for x = l.aux; x != nil; x = x.next { 1529 x.num = i 1530 i++ 1531 1532 // aux struct 1533 Adduint32(ctxt, s, elfhash(x.vers)) // hash 1534 Adduint16(ctxt, s, 0) // flags 1535 Adduint16(ctxt, s, uint16(x.num)) // other - index we refer to this by 1536 Adduint32(ctxt, s, uint32(Addstring(ctxt, dynstr, x.vers))) // version string offset 1537 if x.next != nil { 1538 Adduint32(ctxt, s, 16) // offset from this aux to next 1539 } else { 1540 Adduint32(ctxt, s, 0) 1541 } 1542 } 1543 } 1544 1545 // version references 1546 s = Linklookup(ctxt, ".gnu.version", 0) 1547 1548 for i := 0; i < nsym; i++ { 1549 if i == 0 { 1550 Adduint16(ctxt, s, 0) // first entry - no symbol 1551 } else if need[i] == nil { 1552 Adduint16(ctxt, s, 1) // global 1553 } else { 1554 Adduint16(ctxt, s, uint16(need[i].num)) 1555 } 1556 } 1557 1558 s = Linklookup(ctxt, ".dynamic", 0) 1559 elfverneed = nfile 1560 if elfverneed != 0 { 1561 elfwritedynentsym(ctxt, s, DT_VERNEED, Linklookup(ctxt, ".gnu.version_r", 0)) 1562 Elfwritedynent(ctxt, s, DT_VERNEEDNUM, uint64(nfile)) 1563 elfwritedynentsym(ctxt, s, DT_VERSYM, Linklookup(ctxt, ".gnu.version", 0)) 1564 } 1565 1566 sy := Linklookup(ctxt, elfRelType+".plt", 0) 1567 if sy.Size > 0 { 1568 if elfRelType == ".rela" { 1569 Elfwritedynent(ctxt, s, DT_PLTREL, DT_RELA) 1570 } else { 1571 Elfwritedynent(ctxt, s, DT_PLTREL, DT_REL) 1572 } 1573 elfwritedynentsymsize(ctxt, s, DT_PLTRELSZ, sy) 1574 elfwritedynentsym(ctxt, s, DT_JMPREL, sy) 1575 } 1576 1577 Elfwritedynent(ctxt, s, DT_NULL, 0) 1578 } 1579 1580 func elfphload(ctxt *Link, seg *Segment) *ElfPhdr { 1581 ph := newElfPhdr(ctxt) 1582 ph.type_ = PT_LOAD 1583 if seg.Rwx&4 != 0 { 1584 ph.flags |= PF_R 1585 } 1586 if seg.Rwx&2 != 0 { 1587 ph.flags |= PF_W 1588 } 1589 if seg.Rwx&1 != 0 { 1590 ph.flags |= PF_X 1591 } 1592 ph.vaddr = seg.Vaddr 1593 ph.paddr = seg.Vaddr 1594 ph.memsz = seg.Length 1595 ph.off = seg.Fileoff 1596 ph.filesz = seg.Filelen 1597 ph.align = uint64(*FlagRound) 1598 1599 return ph 1600 } 1601 1602 func elfshname(ctxt *Link, name string) *ElfShdr { 1603 var off int 1604 var sh *ElfShdr 1605 1606 for i := 0; i < nelfstr; i++ { 1607 if name == elfstr[i].s { 1608 off = elfstr[i].off 1609 for i = 0; i < int(ehdr.shnum); i++ { 1610 sh = shdr[i] 1611 if sh.name == uint32(off) { 1612 return sh 1613 } 1614 } 1615 1616 sh = newElfShdr(ctxt, int64(off)) 1617 return sh 1618 } 1619 } 1620 1621 ctxt.Diag("cannot find elf name %s", name) 1622 errorexit() 1623 return nil 1624 } 1625 1626 func elfshalloc(ctxt *Link, sect *Section) *ElfShdr { 1627 sh := elfshname(ctxt, sect.Name) 1628 sect.Elfsect = sh 1629 return sh 1630 } 1631 1632 func elfshbits(ctxt *Link, sect *Section) *ElfShdr { 1633 sh := elfshalloc(ctxt, sect) 1634 // If this section has already been set up as a note, we assume type_ and 1635 // flags are already correct, but the other fields still need filling in. 1636 if sh.type_ == SHT_NOTE { 1637 if Linkmode != LinkExternal { 1638 // TODO(mwhudson): the approach here will work OK when 1639 // linking internally for notes that we want to be included 1640 // in a loadable segment (e.g. the abihash note) but not for 1641 // notes that we do not want to be mapped (e.g. the package 1642 // list note). The real fix is probably to define new values 1643 // for Symbol.Type corresponding to mapped and unmapped notes 1644 // and handle them in dodata(). 1645 ctxt.Diag("sh.type_ == SHT_NOTE in elfshbits when linking internally") 1646 } 1647 sh.addralign = uint64(sect.Align) 1648 sh.size = sect.Length 1649 sh.off = sect.Seg.Fileoff + sect.Vaddr - sect.Seg.Vaddr 1650 return sh 1651 } 1652 if sh.type_ > 0 { 1653 return sh 1654 } 1655 1656 if sect.Vaddr < sect.Seg.Vaddr+sect.Seg.Filelen { 1657 sh.type_ = SHT_PROGBITS 1658 } else { 1659 sh.type_ = SHT_NOBITS 1660 } 1661 sh.flags = SHF_ALLOC 1662 if sect.Rwx&1 != 0 { 1663 sh.flags |= SHF_EXECINSTR 1664 } 1665 if sect.Rwx&2 != 0 { 1666 sh.flags |= SHF_WRITE 1667 } 1668 if sect.Name == ".tbss" { 1669 sh.flags |= SHF_TLS 1670 sh.type_ = SHT_NOBITS 1671 } 1672 if strings.HasPrefix(sect.Name, ".debug") { 1673 sh.flags = 0 1674 } 1675 1676 if Linkmode != LinkExternal { 1677 sh.addr = sect.Vaddr 1678 } 1679 sh.addralign = uint64(sect.Align) 1680 sh.size = sect.Length 1681 if sect.Name != ".tbss" { 1682 sh.off = sect.Seg.Fileoff + sect.Vaddr - sect.Seg.Vaddr 1683 } 1684 1685 return sh 1686 } 1687 1688 func elfshreloc(ctxt *Link, sect *Section) *ElfShdr { 1689 // If main section is SHT_NOBITS, nothing to relocate. 1690 // Also nothing to relocate in .shstrtab or notes. 1691 if sect.Vaddr >= sect.Seg.Vaddr+sect.Seg.Filelen { 1692 return nil 1693 } 1694 if sect.Name == ".shstrtab" || sect.Name == ".tbss" { 1695 return nil 1696 } 1697 if sect.Elfsect.type_ == SHT_NOTE { 1698 return nil 1699 } 1700 1701 var typ int 1702 if elfRelType == ".rela" { 1703 typ = SHT_RELA 1704 } else { 1705 typ = SHT_REL 1706 } 1707 1708 sh := elfshname(ctxt, elfRelType+sect.Name) 1709 sh.type_ = uint32(typ) 1710 sh.entsize = uint64(SysArch.RegSize) * 2 1711 if typ == SHT_RELA { 1712 sh.entsize += uint64(SysArch.RegSize) 1713 } 1714 sh.link = uint32(elfshname(ctxt, ".symtab").shnum) 1715 sh.info = uint32(sect.Elfsect.shnum) 1716 sh.off = sect.Reloff 1717 sh.size = sect.Rellen 1718 sh.addralign = uint64(SysArch.RegSize) 1719 return sh 1720 } 1721 1722 func elfrelocsect(ctxt *Link, sect *Section, syms []*Symbol) { 1723 // If main section is SHT_NOBITS, nothing to relocate. 1724 // Also nothing to relocate in .shstrtab. 1725 if sect.Vaddr >= sect.Seg.Vaddr+sect.Seg.Filelen { 1726 return 1727 } 1728 if sect.Name == ".shstrtab" { 1729 return 1730 } 1731 1732 sect.Reloff = uint64(coutbuf.Offset()) 1733 for i, s := range syms { 1734 if !s.Attr.Reachable() { 1735 continue 1736 } 1737 if uint64(s.Value) >= sect.Vaddr { 1738 syms = syms[i:] 1739 break 1740 } 1741 } 1742 1743 eaddr := int32(sect.Vaddr + sect.Length) 1744 for _, sym := range syms { 1745 if !sym.Attr.Reachable() { 1746 continue 1747 } 1748 if sym.Value >= int64(eaddr) { 1749 break 1750 } 1751 ctxt.Cursym = sym 1752 1753 for ri := 0; ri < len(sym.R); ri++ { 1754 r := &sym.R[ri] 1755 if r.Done != 0 { 1756 continue 1757 } 1758 if r.Xsym == nil { 1759 ctxt.Diag("missing xsym in relocation") 1760 continue 1761 } 1762 if r.Xsym.ElfsymForReloc() == 0 { 1763 ctxt.Diag("reloc %d to non-elf symbol %s (outer=%s) %d", r.Type, r.Sym.Name, r.Xsym.Name, r.Sym.Type) 1764 } 1765 if Thearch.Elfreloc1(ctxt, r, int64(uint64(sym.Value+int64(r.Off))-sect.Vaddr)) < 0 { 1766 ctxt.Diag("unsupported obj reloc %d/%d to %s", r.Type, r.Siz, r.Sym.Name) 1767 } 1768 } 1769 } 1770 1771 sect.Rellen = uint64(coutbuf.Offset()) - sect.Reloff 1772 } 1773 1774 func Elfemitreloc(ctxt *Link) { 1775 for coutbuf.Offset()&7 != 0 { 1776 Cput(0) 1777 } 1778 1779 elfrelocsect(ctxt, Segtext.Sect, ctxt.Textp) 1780 for sect := Segtext.Sect.Next; sect != nil; sect = sect.Next { 1781 elfrelocsect(ctxt, sect, datap) 1782 } 1783 for sect := Segrodata.Sect; sect != nil; sect = sect.Next { 1784 elfrelocsect(ctxt, sect, datap) 1785 } 1786 for sect := Segdata.Sect; sect != nil; sect = sect.Next { 1787 elfrelocsect(ctxt, sect, datap) 1788 } 1789 for sect := Segdwarf.Sect; sect != nil; sect = sect.Next { 1790 elfrelocsect(ctxt, sect, dwarfp) 1791 } 1792 } 1793 1794 func addgonote(ctxt *Link, sectionName string, tag uint32, desc []byte) { 1795 s := Linklookup(ctxt, sectionName, 0) 1796 s.Attr |= AttrReachable 1797 s.Type = obj.SELFROSECT 1798 // namesz 1799 Adduint32(ctxt, s, uint32(len(ELF_NOTE_GO_NAME))) 1800 // descsz 1801 Adduint32(ctxt, s, uint32(len(desc))) 1802 // tag 1803 Adduint32(ctxt, s, tag) 1804 // name + padding 1805 s.P = append(s.P, ELF_NOTE_GO_NAME...) 1806 for len(s.P)%4 != 0 { 1807 s.P = append(s.P, 0) 1808 } 1809 // desc + padding 1810 s.P = append(s.P, desc...) 1811 for len(s.P)%4 != 0 { 1812 s.P = append(s.P, 0) 1813 } 1814 s.Size = int64(len(s.P)) 1815 } 1816 1817 func (ctxt *Link) doelf() { 1818 if !Iself { 1819 return 1820 } 1821 1822 /* predefine strings we need for section headers */ 1823 shstrtab := Linklookup(ctxt, ".shstrtab", 0) 1824 1825 shstrtab.Type = obj.SELFROSECT 1826 shstrtab.Attr |= AttrReachable 1827 1828 Addstring(ctxt, shstrtab, "") 1829 Addstring(ctxt, shstrtab, ".text") 1830 Addstring(ctxt, shstrtab, ".noptrdata") 1831 Addstring(ctxt, shstrtab, ".data") 1832 Addstring(ctxt, shstrtab, ".bss") 1833 Addstring(ctxt, shstrtab, ".noptrbss") 1834 1835 // generate .tbss section (except for OpenBSD where it's not supported) 1836 // for dynamic internal linker or external linking, so that various 1837 // binutils could correctly calculate PT_TLS size. 1838 // see https://golang.org/issue/5200. 1839 if HEADTYPE != obj.Hopenbsd { 1840 if !*FlagD || Linkmode == LinkExternal { 1841 Addstring(ctxt, shstrtab, ".tbss") 1842 } 1843 } 1844 if HEADTYPE == obj.Hnetbsd { 1845 Addstring(ctxt, shstrtab, ".note.netbsd.ident") 1846 } 1847 if HEADTYPE == obj.Hopenbsd { 1848 Addstring(ctxt, shstrtab, ".note.openbsd.ident") 1849 } 1850 if len(buildinfo) > 0 { 1851 Addstring(ctxt, shstrtab, ".note.gnu.build-id") 1852 } 1853 if *flagBuildid != "" { 1854 Addstring(ctxt, shstrtab, ".note.go.buildid") 1855 } 1856 Addstring(ctxt, shstrtab, ".elfdata") 1857 Addstring(ctxt, shstrtab, ".rodata") 1858 // See the comment about data.rel.ro.FOO section names in data.go. 1859 relro_prefix := "" 1860 if UseRelro() { 1861 Addstring(ctxt, shstrtab, ".data.rel.ro") 1862 relro_prefix = ".data.rel.ro" 1863 } 1864 Addstring(ctxt, shstrtab, relro_prefix+".typelink") 1865 Addstring(ctxt, shstrtab, relro_prefix+".itablink") 1866 Addstring(ctxt, shstrtab, relro_prefix+".gosymtab") 1867 Addstring(ctxt, shstrtab, relro_prefix+".gopclntab") 1868 1869 if Linkmode == LinkExternal { 1870 *FlagD = true 1871 1872 Addstring(ctxt, shstrtab, elfRelType+".text") 1873 Addstring(ctxt, shstrtab, elfRelType+".rodata") 1874 Addstring(ctxt, shstrtab, elfRelType+relro_prefix+".typelink") 1875 Addstring(ctxt, shstrtab, elfRelType+relro_prefix+".itablink") 1876 Addstring(ctxt, shstrtab, elfRelType+relro_prefix+".gosymtab") 1877 Addstring(ctxt, shstrtab, elfRelType+relro_prefix+".gopclntab") 1878 Addstring(ctxt, shstrtab, elfRelType+".noptrdata") 1879 Addstring(ctxt, shstrtab, elfRelType+".data") 1880 if UseRelro() { 1881 Addstring(ctxt, shstrtab, elfRelType+".data.rel.ro") 1882 } 1883 1884 // add a .note.GNU-stack section to mark the stack as non-executable 1885 Addstring(ctxt, shstrtab, ".note.GNU-stack") 1886 1887 if Buildmode == BuildmodeShared { 1888 Addstring(ctxt, shstrtab, ".note.go.abihash") 1889 Addstring(ctxt, shstrtab, ".note.go.pkg-list") 1890 Addstring(ctxt, shstrtab, ".note.go.deps") 1891 } 1892 } 1893 1894 hasinitarr := *FlagLinkshared 1895 1896 /* shared library initializer */ 1897 switch Buildmode { 1898 case BuildmodeCArchive, BuildmodeCShared, BuildmodeShared: 1899 hasinitarr = true 1900 } 1901 1902 if hasinitarr { 1903 Addstring(ctxt, shstrtab, ".init_array") 1904 Addstring(ctxt, shstrtab, elfRelType+".init_array") 1905 } 1906 1907 if !*FlagS { 1908 Addstring(ctxt, shstrtab, ".symtab") 1909 Addstring(ctxt, shstrtab, ".strtab") 1910 dwarfaddshstrings(ctxt, shstrtab) 1911 } 1912 1913 Addstring(ctxt, shstrtab, ".shstrtab") 1914 1915 if !*FlagD { /* -d suppresses dynamic loader format */ 1916 Addstring(ctxt, shstrtab, ".interp") 1917 Addstring(ctxt, shstrtab, ".hash") 1918 Addstring(ctxt, shstrtab, ".got") 1919 if SysArch.Family == sys.PPC64 { 1920 Addstring(ctxt, shstrtab, ".glink") 1921 } 1922 Addstring(ctxt, shstrtab, ".got.plt") 1923 Addstring(ctxt, shstrtab, ".dynamic") 1924 Addstring(ctxt, shstrtab, ".dynsym") 1925 Addstring(ctxt, shstrtab, ".dynstr") 1926 Addstring(ctxt, shstrtab, elfRelType) 1927 Addstring(ctxt, shstrtab, elfRelType+".plt") 1928 1929 Addstring(ctxt, shstrtab, ".plt") 1930 Addstring(ctxt, shstrtab, ".gnu.version") 1931 Addstring(ctxt, shstrtab, ".gnu.version_r") 1932 1933 /* dynamic symbol table - first entry all zeros */ 1934 s := Linklookup(ctxt, ".dynsym", 0) 1935 1936 s.Type = obj.SELFROSECT 1937 s.Attr |= AttrReachable 1938 if elf64 { 1939 s.Size += ELF64SYMSIZE 1940 } else { 1941 s.Size += ELF32SYMSIZE 1942 } 1943 1944 /* dynamic string table */ 1945 s = Linklookup(ctxt, ".dynstr", 0) 1946 1947 s.Type = obj.SELFROSECT 1948 s.Attr |= AttrReachable 1949 if s.Size == 0 { 1950 Addstring(ctxt, s, "") 1951 } 1952 dynstr := s 1953 1954 /* relocation table */ 1955 s = Linklookup(ctxt, elfRelType, 0) 1956 s.Attr |= AttrReachable 1957 s.Type = obj.SELFROSECT 1958 1959 /* global offset table */ 1960 s = Linklookup(ctxt, ".got", 0) 1961 1962 s.Attr |= AttrReachable 1963 s.Type = obj.SELFGOT // writable 1964 1965 /* ppc64 glink resolver */ 1966 if SysArch.Family == sys.PPC64 { 1967 s := Linklookup(ctxt, ".glink", 0) 1968 s.Attr |= AttrReachable 1969 s.Type = obj.SELFRXSECT 1970 } 1971 1972 /* hash */ 1973 s = Linklookup(ctxt, ".hash", 0) 1974 1975 s.Attr |= AttrReachable 1976 s.Type = obj.SELFROSECT 1977 1978 s = Linklookup(ctxt, ".got.plt", 0) 1979 s.Attr |= AttrReachable 1980 s.Type = obj.SELFSECT // writable 1981 1982 s = Linklookup(ctxt, ".plt", 0) 1983 1984 s.Attr |= AttrReachable 1985 if SysArch.Family == sys.PPC64 { 1986 // In the ppc64 ABI, .plt is a data section 1987 // written by the dynamic linker. 1988 s.Type = obj.SELFSECT 1989 } else { 1990 s.Type = obj.SELFRXSECT 1991 } 1992 1993 Thearch.Elfsetupplt(ctxt) 1994 1995 s = Linklookup(ctxt, elfRelType+".plt", 0) 1996 s.Attr |= AttrReachable 1997 s.Type = obj.SELFROSECT 1998 1999 s = Linklookup(ctxt, ".gnu.version", 0) 2000 s.Attr |= AttrReachable 2001 s.Type = obj.SELFROSECT 2002 2003 s = Linklookup(ctxt, ".gnu.version_r", 0) 2004 s.Attr |= AttrReachable 2005 s.Type = obj.SELFROSECT 2006 2007 /* define dynamic elf table */ 2008 s = Linklookup(ctxt, ".dynamic", 0) 2009 2010 s.Attr |= AttrReachable 2011 s.Type = obj.SELFSECT // writable 2012 2013 /* 2014 * .dynamic table 2015 */ 2016 elfwritedynentsym(ctxt, s, DT_HASH, Linklookup(ctxt, ".hash", 0)) 2017 2018 elfwritedynentsym(ctxt, s, DT_SYMTAB, Linklookup(ctxt, ".dynsym", 0)) 2019 if elf64 { 2020 Elfwritedynent(ctxt, s, DT_SYMENT, ELF64SYMSIZE) 2021 } else { 2022 Elfwritedynent(ctxt, s, DT_SYMENT, ELF32SYMSIZE) 2023 } 2024 elfwritedynentsym(ctxt, s, DT_STRTAB, Linklookup(ctxt, ".dynstr", 0)) 2025 elfwritedynentsymsize(ctxt, s, DT_STRSZ, Linklookup(ctxt, ".dynstr", 0)) 2026 if elfRelType == ".rela" { 2027 elfwritedynentsym(ctxt, s, DT_RELA, Linklookup(ctxt, ".rela", 0)) 2028 elfwritedynentsymsize(ctxt, s, DT_RELASZ, Linklookup(ctxt, ".rela", 0)) 2029 Elfwritedynent(ctxt, s, DT_RELAENT, ELF64RELASIZE) 2030 } else { 2031 elfwritedynentsym(ctxt, s, DT_REL, Linklookup(ctxt, ".rel", 0)) 2032 elfwritedynentsymsize(ctxt, s, DT_RELSZ, Linklookup(ctxt, ".rel", 0)) 2033 Elfwritedynent(ctxt, s, DT_RELENT, ELF32RELSIZE) 2034 } 2035 2036 if rpath.val != "" { 2037 Elfwritedynent(ctxt, s, DT_RUNPATH, uint64(Addstring(ctxt, dynstr, rpath.val))) 2038 } 2039 2040 if SysArch.Family == sys.PPC64 { 2041 elfwritedynentsym(ctxt, s, DT_PLTGOT, Linklookup(ctxt, ".plt", 0)) 2042 } else if SysArch.Family == sys.S390X { 2043 elfwritedynentsym(ctxt, s, DT_PLTGOT, Linklookup(ctxt, ".got", 0)) 2044 } else { 2045 elfwritedynentsym(ctxt, s, DT_PLTGOT, Linklookup(ctxt, ".got.plt", 0)) 2046 } 2047 2048 if SysArch.Family == sys.PPC64 { 2049 Elfwritedynent(ctxt, s, DT_PPC64_OPT, 0) 2050 } 2051 2052 // Solaris dynamic linker can't handle an empty .rela.plt if 2053 // DT_JMPREL is emitted so we have to defer generation of DT_PLTREL, 2054 // DT_PLTRELSZ, and DT_JMPREL dynamic entries until after we know the 2055 // size of .rel(a).plt section. 2056 Elfwritedynent(ctxt, s, DT_DEBUG, 0) 2057 } 2058 2059 if Buildmode == BuildmodeShared { 2060 // The go.link.abihashbytes symbol will be pointed at the appropriate 2061 // part of the .note.go.abihash section in data.go:func address(). 2062 s := Linklookup(ctxt, "go.link.abihashbytes", 0) 2063 s.Attr |= AttrLocal 2064 s.Type = obj.SRODATA 2065 s.Attr |= AttrSpecial 2066 s.Attr |= AttrReachable 2067 s.Size = int64(sha1.Size) 2068 2069 sort.Sort(byPkg(ctxt.Library)) 2070 h := sha1.New() 2071 for _, l := range ctxt.Library { 2072 h.Write(l.hash) 2073 } 2074 addgonote(ctxt, ".note.go.abihash", ELF_NOTE_GOABIHASH_TAG, h.Sum([]byte{})) 2075 addgonote(ctxt, ".note.go.pkg-list", ELF_NOTE_GOPKGLIST_TAG, pkglistfornote) 2076 var deplist []string 2077 for _, shlib := range ctxt.Shlibs { 2078 deplist = append(deplist, filepath.Base(shlib.Path)) 2079 } 2080 addgonote(ctxt, ".note.go.deps", ELF_NOTE_GODEPS_TAG, []byte(strings.Join(deplist, "\n"))) 2081 } 2082 2083 if Linkmode == LinkExternal && *flagBuildid != "" { 2084 addgonote(ctxt, ".note.go.buildid", ELF_NOTE_GOBUILDID_TAG, []byte(*flagBuildid)) 2085 } 2086 } 2087 2088 // Do not write DT_NULL. elfdynhash will finish it. 2089 func shsym(ctxt *Link, sh *ElfShdr, s *Symbol) { 2090 addr := Symaddr(ctxt, s) 2091 if sh.flags&SHF_ALLOC != 0 { 2092 sh.addr = uint64(addr) 2093 } 2094 sh.off = uint64(datoff(ctxt, addr)) 2095 sh.size = uint64(s.Size) 2096 } 2097 2098 func phsh(ph *ElfPhdr, sh *ElfShdr) { 2099 ph.vaddr = sh.addr 2100 ph.paddr = ph.vaddr 2101 ph.off = sh.off 2102 ph.filesz = sh.size 2103 ph.memsz = sh.size 2104 ph.align = sh.addralign 2105 } 2106 2107 func Asmbelfsetup(ctxt *Link) { 2108 /* This null SHdr must appear before all others */ 2109 elfshname(ctxt, "") 2110 2111 for sect := Segtext.Sect; sect != nil; sect = sect.Next { 2112 elfshalloc(ctxt, sect) 2113 } 2114 for sect := Segrodata.Sect; sect != nil; sect = sect.Next { 2115 elfshalloc(ctxt, sect) 2116 } 2117 for sect := Segdata.Sect; sect != nil; sect = sect.Next { 2118 elfshalloc(ctxt, sect) 2119 } 2120 for sect := Segdwarf.Sect; sect != nil; sect = sect.Next { 2121 elfshalloc(ctxt, sect) 2122 } 2123 } 2124 2125 func Asmbelf(ctxt *Link, symo int64) { 2126 eh := getElfEhdr() 2127 switch SysArch.Family { 2128 default: 2129 Exitf("unknown architecture in asmbelf: %v", SysArch.Family) 2130 case sys.MIPS64: 2131 eh.machine = EM_MIPS 2132 case sys.ARM: 2133 eh.machine = EM_ARM 2134 case sys.AMD64: 2135 eh.machine = EM_X86_64 2136 case sys.ARM64: 2137 eh.machine = EM_AARCH64 2138 case sys.I386: 2139 eh.machine = EM_386 2140 case sys.PPC64: 2141 eh.machine = EM_PPC64 2142 case sys.S390X: 2143 eh.machine = EM_S390 2144 } 2145 2146 elfreserve := int64(ELFRESERVE) 2147 startva := *FlagTextAddr - int64(HEADR) 2148 resoff := elfreserve 2149 2150 var pph *ElfPhdr 2151 var pnote *ElfPhdr 2152 if Linkmode == LinkExternal { 2153 /* skip program headers */ 2154 eh.phoff = 0 2155 2156 eh.phentsize = 0 2157 2158 if Buildmode == BuildmodeShared { 2159 sh := elfshname(ctxt, ".note.go.pkg-list") 2160 sh.type_ = SHT_NOTE 2161 sh = elfshname(ctxt, ".note.go.abihash") 2162 sh.type_ = SHT_NOTE 2163 sh.flags = SHF_ALLOC 2164 sh = elfshname(ctxt, ".note.go.deps") 2165 sh.type_ = SHT_NOTE 2166 } 2167 2168 if *flagBuildid != "" { 2169 sh := elfshname(ctxt, ".note.go.buildid") 2170 sh.type_ = SHT_NOTE 2171 sh.flags = SHF_ALLOC 2172 } 2173 2174 goto elfobj 2175 } 2176 2177 /* program header info */ 2178 pph = newElfPhdr(ctxt) 2179 2180 pph.type_ = PT_PHDR 2181 pph.flags = PF_R 2182 pph.off = uint64(eh.ehsize) 2183 pph.vaddr = uint64(*FlagTextAddr) - uint64(HEADR) + pph.off 2184 pph.paddr = uint64(*FlagTextAddr) - uint64(HEADR) + pph.off 2185 pph.align = uint64(*FlagRound) 2186 2187 /* 2188 * PHDR must be in a loaded segment. Adjust the text 2189 * segment boundaries downwards to include it. 2190 * Except on NaCl where it must not be loaded. 2191 */ 2192 if HEADTYPE != obj.Hnacl { 2193 o := int64(Segtext.Vaddr - pph.vaddr) 2194 Segtext.Vaddr -= uint64(o) 2195 Segtext.Length += uint64(o) 2196 o = int64(Segtext.Fileoff - pph.off) 2197 Segtext.Fileoff -= uint64(o) 2198 Segtext.Filelen += uint64(o) 2199 } 2200 2201 if !*FlagD { /* -d suppresses dynamic loader format */ 2202 /* interpreter */ 2203 sh := elfshname(ctxt, ".interp") 2204 2205 sh.type_ = SHT_PROGBITS 2206 sh.flags = SHF_ALLOC 2207 sh.addralign = 1 2208 if interpreter == "" { 2209 switch HEADTYPE { 2210 case obj.Hlinux: 2211 interpreter = Thearch.Linuxdynld 2212 2213 case obj.Hfreebsd: 2214 interpreter = Thearch.Freebsddynld 2215 2216 case obj.Hnetbsd: 2217 interpreter = Thearch.Netbsddynld 2218 2219 case obj.Hopenbsd: 2220 interpreter = Thearch.Openbsddynld 2221 2222 case obj.Hdragonfly: 2223 interpreter = Thearch.Dragonflydynld 2224 2225 case obj.Hsolaris: 2226 interpreter = Thearch.Solarisdynld 2227 } 2228 } 2229 2230 resoff -= int64(elfinterp(sh, uint64(startva), uint64(resoff), interpreter)) 2231 2232 ph := newElfPhdr(ctxt) 2233 ph.type_ = PT_INTERP 2234 ph.flags = PF_R 2235 phsh(ph, sh) 2236 } 2237 2238 pnote = nil 2239 if HEADTYPE == obj.Hnetbsd || HEADTYPE == obj.Hopenbsd { 2240 var sh *ElfShdr 2241 switch HEADTYPE { 2242 case obj.Hnetbsd: 2243 sh = elfshname(ctxt, ".note.netbsd.ident") 2244 resoff -= int64(elfnetbsdsig(sh, uint64(startva), uint64(resoff))) 2245 2246 case obj.Hopenbsd: 2247 sh = elfshname(ctxt, ".note.openbsd.ident") 2248 resoff -= int64(elfopenbsdsig(sh, uint64(startva), uint64(resoff))) 2249 } 2250 2251 pnote = newElfPhdr(ctxt) 2252 pnote.type_ = PT_NOTE 2253 pnote.flags = PF_R 2254 phsh(pnote, sh) 2255 } 2256 2257 if len(buildinfo) > 0 { 2258 sh := elfshname(ctxt, ".note.gnu.build-id") 2259 resoff -= int64(elfbuildinfo(sh, uint64(startva), uint64(resoff))) 2260 2261 if pnote == nil { 2262 pnote = newElfPhdr(ctxt) 2263 pnote.type_ = PT_NOTE 2264 pnote.flags = PF_R 2265 } 2266 2267 phsh(pnote, sh) 2268 } 2269 2270 if *flagBuildid != "" { 2271 sh := elfshname(ctxt, ".note.go.buildid") 2272 resoff -= int64(elfgobuildid(sh, uint64(startva), uint64(resoff))) 2273 2274 pnote := newElfPhdr(ctxt) 2275 pnote.type_ = PT_NOTE 2276 pnote.flags = PF_R 2277 phsh(pnote, sh) 2278 } 2279 2280 // Additions to the reserved area must be above this line. 2281 2282 elfphload(ctxt, &Segtext) 2283 if Segrodata.Sect != nil { 2284 elfphload(ctxt, &Segrodata) 2285 } 2286 elfphload(ctxt, &Segdata) 2287 2288 /* Dynamic linking sections */ 2289 if !*FlagD { 2290 sh := elfshname(ctxt, ".dynsym") 2291 sh.type_ = SHT_DYNSYM 2292 sh.flags = SHF_ALLOC 2293 if elf64 { 2294 sh.entsize = ELF64SYMSIZE 2295 } else { 2296 sh.entsize = ELF32SYMSIZE 2297 } 2298 sh.addralign = uint64(SysArch.RegSize) 2299 sh.link = uint32(elfshname(ctxt, ".dynstr").shnum) 2300 2301 // sh->info = index of first non-local symbol (number of local symbols) 2302 shsym(ctxt, sh, Linklookup(ctxt, ".dynsym", 0)) 2303 2304 sh = elfshname(ctxt, ".dynstr") 2305 sh.type_ = SHT_STRTAB 2306 sh.flags = SHF_ALLOC 2307 sh.addralign = 1 2308 shsym(ctxt, sh, Linklookup(ctxt, ".dynstr", 0)) 2309 2310 if elfverneed != 0 { 2311 sh := elfshname(ctxt, ".gnu.version") 2312 sh.type_ = SHT_GNU_VERSYM 2313 sh.flags = SHF_ALLOC 2314 sh.addralign = 2 2315 sh.link = uint32(elfshname(ctxt, ".dynsym").shnum) 2316 sh.entsize = 2 2317 shsym(ctxt, sh, Linklookup(ctxt, ".gnu.version", 0)) 2318 2319 sh = elfshname(ctxt, ".gnu.version_r") 2320 sh.type_ = SHT_GNU_VERNEED 2321 sh.flags = SHF_ALLOC 2322 sh.addralign = uint64(SysArch.RegSize) 2323 sh.info = uint32(elfverneed) 2324 sh.link = uint32(elfshname(ctxt, ".dynstr").shnum) 2325 shsym(ctxt, sh, Linklookup(ctxt, ".gnu.version_r", 0)) 2326 } 2327 2328 if elfRelType == ".rela" { 2329 sh := elfshname(ctxt, ".rela.plt") 2330 sh.type_ = SHT_RELA 2331 sh.flags = SHF_ALLOC 2332 sh.entsize = ELF64RELASIZE 2333 sh.addralign = uint64(SysArch.RegSize) 2334 sh.link = uint32(elfshname(ctxt, ".dynsym").shnum) 2335 sh.info = uint32(elfshname(ctxt, ".plt").shnum) 2336 shsym(ctxt, sh, Linklookup(ctxt, ".rela.plt", 0)) 2337 2338 sh = elfshname(ctxt, ".rela") 2339 sh.type_ = SHT_RELA 2340 sh.flags = SHF_ALLOC 2341 sh.entsize = ELF64RELASIZE 2342 sh.addralign = 8 2343 sh.link = uint32(elfshname(ctxt, ".dynsym").shnum) 2344 shsym(ctxt, sh, Linklookup(ctxt, ".rela", 0)) 2345 } else { 2346 sh := elfshname(ctxt, ".rel.plt") 2347 sh.type_ = SHT_REL 2348 sh.flags = SHF_ALLOC 2349 sh.entsize = ELF32RELSIZE 2350 sh.addralign = 4 2351 sh.link = uint32(elfshname(ctxt, ".dynsym").shnum) 2352 shsym(ctxt, sh, Linklookup(ctxt, ".rel.plt", 0)) 2353 2354 sh = elfshname(ctxt, ".rel") 2355 sh.type_ = SHT_REL 2356 sh.flags = SHF_ALLOC 2357 sh.entsize = ELF32RELSIZE 2358 sh.addralign = 4 2359 sh.link = uint32(elfshname(ctxt, ".dynsym").shnum) 2360 shsym(ctxt, sh, Linklookup(ctxt, ".rel", 0)) 2361 } 2362 2363 if eh.machine == EM_PPC64 { 2364 sh := elfshname(ctxt, ".glink") 2365 sh.type_ = SHT_PROGBITS 2366 sh.flags = SHF_ALLOC + SHF_EXECINSTR 2367 sh.addralign = 4 2368 shsym(ctxt, sh, Linklookup(ctxt, ".glink", 0)) 2369 } 2370 2371 sh = elfshname(ctxt, ".plt") 2372 sh.type_ = SHT_PROGBITS 2373 sh.flags = SHF_ALLOC + SHF_EXECINSTR 2374 if eh.machine == EM_X86_64 { 2375 sh.entsize = 16 2376 } else if eh.machine == EM_S390 { 2377 sh.entsize = 32 2378 } else if eh.machine == EM_PPC64 { 2379 // On ppc64, this is just a table of addresses 2380 // filled by the dynamic linker 2381 sh.type_ = SHT_NOBITS 2382 2383 sh.flags = SHF_ALLOC + SHF_WRITE 2384 sh.entsize = 8 2385 } else { 2386 sh.entsize = 4 2387 } 2388 sh.addralign = sh.entsize 2389 shsym(ctxt, sh, Linklookup(ctxt, ".plt", 0)) 2390 2391 // On ppc64, .got comes from the input files, so don't 2392 // create it here, and .got.plt is not used. 2393 if eh.machine != EM_PPC64 { 2394 sh := elfshname(ctxt, ".got") 2395 sh.type_ = SHT_PROGBITS 2396 sh.flags = SHF_ALLOC + SHF_WRITE 2397 sh.entsize = uint64(SysArch.RegSize) 2398 sh.addralign = uint64(SysArch.RegSize) 2399 shsym(ctxt, sh, Linklookup(ctxt, ".got", 0)) 2400 2401 sh = elfshname(ctxt, ".got.plt") 2402 sh.type_ = SHT_PROGBITS 2403 sh.flags = SHF_ALLOC + SHF_WRITE 2404 sh.entsize = uint64(SysArch.RegSize) 2405 sh.addralign = uint64(SysArch.RegSize) 2406 shsym(ctxt, sh, Linklookup(ctxt, ".got.plt", 0)) 2407 } 2408 2409 sh = elfshname(ctxt, ".hash") 2410 sh.type_ = SHT_HASH 2411 sh.flags = SHF_ALLOC 2412 sh.entsize = 4 2413 sh.addralign = uint64(SysArch.RegSize) 2414 sh.link = uint32(elfshname(ctxt, ".dynsym").shnum) 2415 shsym(ctxt, sh, Linklookup(ctxt, ".hash", 0)) 2416 2417 /* sh and PT_DYNAMIC for .dynamic section */ 2418 sh = elfshname(ctxt, ".dynamic") 2419 2420 sh.type_ = SHT_DYNAMIC 2421 sh.flags = SHF_ALLOC + SHF_WRITE 2422 sh.entsize = 2 * uint64(SysArch.RegSize) 2423 sh.addralign = uint64(SysArch.RegSize) 2424 sh.link = uint32(elfshname(ctxt, ".dynstr").shnum) 2425 shsym(ctxt, sh, Linklookup(ctxt, ".dynamic", 0)) 2426 ph := newElfPhdr(ctxt) 2427 ph.type_ = PT_DYNAMIC 2428 ph.flags = PF_R + PF_W 2429 phsh(ph, sh) 2430 2431 /* 2432 * Thread-local storage segment (really just size). 2433 */ 2434 // Do not emit PT_TLS for OpenBSD since ld.so(1) does 2435 // not currently support it. This is handled 2436 // appropriately in runtime/cgo. 2437 if HEADTYPE != obj.Hopenbsd { 2438 tlssize := uint64(0) 2439 for sect := Segdata.Sect; sect != nil; sect = sect.Next { 2440 if sect.Name == ".tbss" { 2441 tlssize = sect.Length 2442 } 2443 } 2444 if tlssize != 0 { 2445 ph := newElfPhdr(ctxt) 2446 ph.type_ = PT_TLS 2447 ph.flags = PF_R 2448 ph.memsz = tlssize 2449 ph.align = uint64(SysArch.RegSize) 2450 } 2451 } 2452 } 2453 2454 if HEADTYPE == obj.Hlinux { 2455 ph := newElfPhdr(ctxt) 2456 ph.type_ = PT_GNU_STACK 2457 ph.flags = PF_W + PF_R 2458 ph.align = uint64(SysArch.RegSize) 2459 2460 ph = newElfPhdr(ctxt) 2461 ph.type_ = PT_PAX_FLAGS 2462 ph.flags = 0x2a00 // mprotect, randexec, emutramp disabled 2463 ph.align = uint64(SysArch.RegSize) 2464 } 2465 2466 elfobj: 2467 sh := elfshname(ctxt, ".shstrtab") 2468 sh.type_ = SHT_STRTAB 2469 sh.addralign = 1 2470 shsym(ctxt, sh, Linklookup(ctxt, ".shstrtab", 0)) 2471 eh.shstrndx = uint16(sh.shnum) 2472 2473 // put these sections early in the list 2474 if !*FlagS { 2475 elfshname(ctxt, ".symtab") 2476 elfshname(ctxt, ".strtab") 2477 } 2478 2479 for sect := Segtext.Sect; sect != nil; sect = sect.Next { 2480 elfshbits(ctxt, sect) 2481 } 2482 for sect := Segrodata.Sect; sect != nil; sect = sect.Next { 2483 elfshbits(ctxt, sect) 2484 } 2485 for sect := Segdata.Sect; sect != nil; sect = sect.Next { 2486 elfshbits(ctxt, sect) 2487 } 2488 for sect := Segdwarf.Sect; sect != nil; sect = sect.Next { 2489 elfshbits(ctxt, sect) 2490 } 2491 2492 if Linkmode == LinkExternal { 2493 for sect := Segtext.Sect; sect != nil; sect = sect.Next { 2494 elfshreloc(ctxt, sect) 2495 } 2496 for sect := Segrodata.Sect; sect != nil; sect = sect.Next { 2497 elfshreloc(ctxt, sect) 2498 } 2499 for sect := Segdata.Sect; sect != nil; sect = sect.Next { 2500 elfshreloc(ctxt, sect) 2501 } 2502 for _, s := range dwarfp { 2503 if len(s.R) > 0 || s.Type == obj.SDWARFINFO { 2504 elfshreloc(ctxt, s.Sect) 2505 } 2506 if s.Type == obj.SDWARFINFO { 2507 break 2508 } 2509 } 2510 // add a .note.GNU-stack section to mark the stack as non-executable 2511 sh := elfshname(ctxt, ".note.GNU-stack") 2512 2513 sh.type_ = SHT_PROGBITS 2514 sh.addralign = 1 2515 sh.flags = 0 2516 } 2517 2518 if !*FlagS { 2519 sh := elfshname(ctxt, ".symtab") 2520 sh.type_ = SHT_SYMTAB 2521 sh.off = uint64(symo) 2522 sh.size = uint64(Symsize) 2523 sh.addralign = uint64(SysArch.RegSize) 2524 sh.entsize = 8 + 2*uint64(SysArch.RegSize) 2525 sh.link = uint32(elfshname(ctxt, ".strtab").shnum) 2526 sh.info = uint32(elfglobalsymndx) 2527 2528 sh = elfshname(ctxt, ".strtab") 2529 sh.type_ = SHT_STRTAB 2530 sh.off = uint64(symo) + uint64(Symsize) 2531 sh.size = uint64(len(Elfstrdat)) 2532 sh.addralign = 1 2533 } 2534 2535 /* Main header */ 2536 eh.ident[EI_MAG0] = '\177' 2537 2538 eh.ident[EI_MAG1] = 'E' 2539 eh.ident[EI_MAG2] = 'L' 2540 eh.ident[EI_MAG3] = 'F' 2541 if HEADTYPE == obj.Hfreebsd { 2542 eh.ident[EI_OSABI] = ELFOSABI_FREEBSD 2543 } else if HEADTYPE == obj.Hnetbsd { 2544 eh.ident[EI_OSABI] = ELFOSABI_NETBSD 2545 } else if HEADTYPE == obj.Hopenbsd { 2546 eh.ident[EI_OSABI] = ELFOSABI_OPENBSD 2547 } else if HEADTYPE == obj.Hdragonfly { 2548 eh.ident[EI_OSABI] = ELFOSABI_NONE 2549 } 2550 if elf64 { 2551 eh.ident[EI_CLASS] = ELFCLASS64 2552 } else { 2553 eh.ident[EI_CLASS] = ELFCLASS32 2554 } 2555 if ctxt.Arch.ByteOrder == binary.BigEndian { 2556 eh.ident[EI_DATA] = ELFDATA2MSB 2557 } else { 2558 eh.ident[EI_DATA] = ELFDATA2LSB 2559 } 2560 eh.ident[EI_VERSION] = EV_CURRENT 2561 2562 if Linkmode == LinkExternal { 2563 eh.type_ = ET_REL 2564 } else { 2565 eh.type_ = ET_EXEC 2566 } 2567 2568 if Linkmode != LinkExternal { 2569 eh.entry = uint64(Entryvalue(ctxt)) 2570 } 2571 2572 eh.version = EV_CURRENT 2573 2574 if pph != nil { 2575 pph.filesz = uint64(eh.phnum) * uint64(eh.phentsize) 2576 pph.memsz = pph.filesz 2577 } 2578 2579 Cseek(0) 2580 a := int64(0) 2581 a += int64(elfwritehdr()) 2582 a += int64(elfwritephdrs()) 2583 a += int64(elfwriteshdrs()) 2584 if !*FlagD { 2585 a += int64(elfwriteinterp(ctxt)) 2586 } 2587 if Linkmode != LinkExternal { 2588 if HEADTYPE == obj.Hnetbsd { 2589 a += int64(elfwritenetbsdsig(ctxt)) 2590 } 2591 if HEADTYPE == obj.Hopenbsd { 2592 a += int64(elfwriteopenbsdsig(ctxt)) 2593 } 2594 if len(buildinfo) > 0 { 2595 a += int64(elfwritebuildinfo(ctxt)) 2596 } 2597 if *flagBuildid != "" { 2598 a += int64(elfwritegobuildid(ctxt)) 2599 } 2600 } 2601 2602 if a > elfreserve { 2603 ctxt.Diag("ELFRESERVE too small: %d > %d", a, elfreserve) 2604 } 2605 } 2606 2607 func Elfadddynsym(ctxt *Link, s *Symbol) { 2608 if elf64 { 2609 s.Dynid = int32(Nelfsym) 2610 Nelfsym++ 2611 2612 d := Linklookup(ctxt, ".dynsym", 0) 2613 2614 name := s.Extname 2615 Adduint32(ctxt, d, uint32(Addstring(ctxt, Linklookup(ctxt, ".dynstr", 0), name))) 2616 2617 /* type */ 2618 t := STB_GLOBAL << 4 2619 2620 if s.Attr.CgoExport() && s.Type&obj.SMASK == obj.STEXT { 2621 t |= STT_FUNC 2622 } else { 2623 t |= STT_OBJECT 2624 } 2625 Adduint8(ctxt, d, uint8(t)) 2626 2627 /* reserved */ 2628 Adduint8(ctxt, d, 0) 2629 2630 /* section where symbol is defined */ 2631 if s.Type == obj.SDYNIMPORT { 2632 Adduint16(ctxt, d, SHN_UNDEF) 2633 } else { 2634 Adduint16(ctxt, d, 1) 2635 } 2636 2637 /* value */ 2638 if s.Type == obj.SDYNIMPORT { 2639 Adduint64(ctxt, d, 0) 2640 } else { 2641 Addaddr(ctxt, d, s) 2642 } 2643 2644 /* size of object */ 2645 Adduint64(ctxt, d, uint64(s.Size)) 2646 2647 if SysArch.Family == sys.AMD64 && !s.Attr.CgoExportDynamic() && s.Dynimplib != "" && !seenlib[s.Dynimplib] { 2648 Elfwritedynent(ctxt, Linklookup(ctxt, ".dynamic", 0), DT_NEEDED, uint64(Addstring(ctxt, Linklookup(ctxt, ".dynstr", 0), s.Dynimplib))) 2649 } 2650 } else { 2651 s.Dynid = int32(Nelfsym) 2652 Nelfsym++ 2653 2654 d := Linklookup(ctxt, ".dynsym", 0) 2655 2656 /* name */ 2657 name := s.Extname 2658 2659 Adduint32(ctxt, d, uint32(Addstring(ctxt, Linklookup(ctxt, ".dynstr", 0), name))) 2660 2661 /* value */ 2662 if s.Type == obj.SDYNIMPORT { 2663 Adduint32(ctxt, d, 0) 2664 } else { 2665 Addaddr(ctxt, d, s) 2666 } 2667 2668 /* size of object */ 2669 Adduint32(ctxt, d, uint32(s.Size)) 2670 2671 /* type */ 2672 t := STB_GLOBAL << 4 2673 2674 // TODO(mwhudson): presumably the behaviour should actually be the same on both arm and 386. 2675 if SysArch.Family == sys.I386 && s.Attr.CgoExport() && s.Type&obj.SMASK == obj.STEXT { 2676 t |= STT_FUNC 2677 } else if SysArch.Family == sys.ARM && s.Attr.CgoExportDynamic() && s.Type&obj.SMASK == obj.STEXT { 2678 t |= STT_FUNC 2679 } else { 2680 t |= STT_OBJECT 2681 } 2682 Adduint8(ctxt, d, uint8(t)) 2683 Adduint8(ctxt, d, 0) 2684 2685 /* shndx */ 2686 if s.Type == obj.SDYNIMPORT { 2687 Adduint16(ctxt, d, SHN_UNDEF) 2688 } else { 2689 Adduint16(ctxt, d, 1) 2690 } 2691 } 2692 } 2693 2694 func ELF32_R_SYM(info uint32) uint32 { 2695 return info >> 8 2696 } 2697 2698 func ELF32_R_TYPE(info uint32) uint32 { 2699 return uint32(uint8(info)) 2700 } 2701 2702 func ELF32_R_INFO(sym uint32, type_ uint32) uint32 { 2703 return sym<<8 | type_ 2704 } 2705 2706 func ELF32_ST_BIND(info uint8) uint8 { 2707 return info >> 4 2708 } 2709 2710 func ELF32_ST_TYPE(info uint8) uint8 { 2711 return info & 0xf 2712 } 2713 2714 func ELF32_ST_INFO(bind uint8, type_ uint8) uint8 { 2715 return bind<<4 | type_&0xf 2716 } 2717 2718 func ELF32_ST_VISIBILITY(oth uint8) uint8 { 2719 return oth & 3 2720 } 2721 2722 func ELF64_R_SYM(info uint64) uint32 { 2723 return uint32(info >> 32) 2724 } 2725 2726 func ELF64_R_TYPE(info uint64) uint32 { 2727 return uint32(info) 2728 } 2729 2730 func ELF64_R_INFO(sym uint32, type_ uint32) uint64 { 2731 return uint64(sym)<<32 | uint64(type_) 2732 } 2733 2734 func ELF64_ST_BIND(info uint8) uint8 { 2735 return info >> 4 2736 } 2737 2738 func ELF64_ST_TYPE(info uint8) uint8 { 2739 return info & 0xf 2740 } 2741 2742 func ELF64_ST_INFO(bind uint8, type_ uint8) uint8 { 2743 return bind<<4 | type_&0xf 2744 } 2745 2746 func ELF64_ST_VISIBILITY(oth uint8) uint8 { 2747 return oth & 3 2748 }