1 /* AArch64-specific support for ELF. 2 Copyright (C) 2009-2015 Free Software Foundation, Inc. 3 Contributed by ARM Ltd. 4 5 This file is part of BFD, the Binary File Descriptor library. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; see the file COPYING3. If not, 19 see <http://www.gnu.org/licenses/>. */ 20 21 #include "sysdep.h" 22 #include "elfxx-aarch64.h" 23 #include <stdarg.h> 24 #include <string.h> 25 26 #define MASK(n) ((1u << (n)) - 1) 27 28 /* Decode the 26-bit offset of unconditional branch. */ 29 static inline uint32_t 30 decode_branch_ofs_26 (uint32_t insn) 31 { 32 return insn & MASK (26); 33 } 34 35 /* Decode the 19-bit offset of conditional branch and compare & branch. */ 36 static inline uint32_t 37 decode_cond_branch_ofs_19 (uint32_t insn) 38 { 39 return (insn >> 5) & MASK (19); 40 } 41 42 /* Decode the 19-bit offset of load literal. */ 43 static inline uint32_t 44 decode_ld_lit_ofs_19 (uint32_t insn) 45 { 46 return (insn >> 5) & MASK (19); 47 } 48 49 /* Decode the 14-bit offset of test & branch. */ 50 static inline uint32_t 51 decode_tst_branch_ofs_14 (uint32_t insn) 52 { 53 return (insn >> 5) & MASK (14); 54 } 55 56 /* Decode the 16-bit imm of move wide. */ 57 static inline uint32_t 58 decode_movw_imm (uint32_t insn) 59 { 60 return (insn >> 5) & MASK (16); 61 } 62 63 /* Decode the 12-bit imm of add immediate. */ 64 static inline uint32_t 65 decode_add_imm (uint32_t insn) 66 { 67 return (insn >> 10) & MASK (12); 68 } 69 70 /* Reencode the imm field of add immediate. */ 71 static inline uint32_t 72 reencode_add_imm (uint32_t insn, uint32_t imm) 73 { 74 return (insn & ~(MASK (12) << 10)) | ((imm & MASK (12)) << 10); 75 } 76 77 /* Reencode the imm field of adr. */ 78 static inline uint32_t 79 reencode_adr_imm (uint32_t insn, uint32_t imm) 80 { 81 return (insn & ~((MASK (2) << 29) | (MASK (19) << 5))) 82 | ((imm & MASK (2)) << 29) | ((imm & (MASK (19) << 2)) << 3); 83 } 84 85 /* Reencode the imm field of ld/st pos immediate. */ 86 static inline uint32_t 87 reencode_ldst_pos_imm (uint32_t insn, uint32_t imm) 88 { 89 return (insn & ~(MASK (12) << 10)) | ((imm & MASK (12)) << 10); 90 } 91 92 /* Encode the 26-bit offset of unconditional branch. */ 93 static inline uint32_t 94 reencode_branch_ofs_26 (uint32_t insn, uint32_t ofs) 95 { 96 return (insn & ~MASK (26)) | (ofs & MASK (26)); 97 } 98 99 /* Encode the 19-bit offset of conditional branch and compare & branch. */ 100 static inline uint32_t 101 reencode_cond_branch_ofs_19 (uint32_t insn, uint32_t ofs) 102 { 103 return (insn & ~(MASK (19) << 5)) | ((ofs & MASK (19)) << 5); 104 } 105 106 /* Decode the 19-bit offset of load literal. */ 107 static inline uint32_t 108 reencode_ld_lit_ofs_19 (uint32_t insn, uint32_t ofs) 109 { 110 return (insn & ~(MASK (19) << 5)) | ((ofs & MASK (19)) << 5); 111 } 112 113 /* Encode the 14-bit offset of test & branch. */ 114 static inline uint32_t 115 reencode_tst_branch_ofs_14 (uint32_t insn, uint32_t ofs) 116 { 117 return (insn & ~(MASK (14) << 5)) | ((ofs & MASK (14)) << 5); 118 } 119 120 /* Reencode the imm field of move wide. */ 121 static inline uint32_t 122 reencode_movw_imm (uint32_t insn, uint32_t imm) 123 { 124 return (insn & ~(MASK (16) << 5)) | ((imm & MASK (16)) << 5); 125 } 126 127 /* Reencode mov[zn] to movz. */ 128 static inline uint32_t 129 reencode_movzn_to_movz (uint32_t opcode) 130 { 131 return opcode | (1 << 30); 132 } 133 134 /* Reencode mov[zn] to movn. */ 135 static inline uint32_t 136 reencode_movzn_to_movn (uint32_t opcode) 137 { 138 return opcode & ~(1 << 30); 139 } 140 141 /* Return non-zero if the indicated VALUE has overflowed the maximum 142 range expressible by a unsigned number with the indicated number of 143 BITS. */ 144 145 static bfd_reloc_status_type 146 aarch64_unsigned_overflow (bfd_vma value, unsigned int bits) 147 { 148 bfd_vma lim; 149 if (bits >= sizeof (bfd_vma) * 8) 150 return bfd_reloc_ok; 151 lim = (bfd_vma) 1 << bits; 152 if (value >= lim) 153 return bfd_reloc_overflow; 154 return bfd_reloc_ok; 155 } 156 157 /* Return non-zero if the indicated VALUE has overflowed the maximum 158 range expressible by an signed number with the indicated number of 159 BITS. */ 160 161 static bfd_reloc_status_type 162 aarch64_signed_overflow (bfd_vma value, unsigned int bits) 163 { 164 bfd_signed_vma svalue = (bfd_signed_vma) value; 165 bfd_signed_vma lim; 166 167 if (bits >= sizeof (bfd_vma) * 8) 168 return bfd_reloc_ok; 169 lim = (bfd_signed_vma) 1 << (bits - 1); 170 if (svalue < -lim || svalue >= lim) 171 return bfd_reloc_overflow; 172 return bfd_reloc_ok; 173 } 174 175 /* Insert the addend/value into the instruction or data object being 176 relocated. */ 177 bfd_reloc_status_type 178 _bfd_aarch64_elf_put_addend (bfd *abfd, 179 bfd_byte *address, bfd_reloc_code_real_type r_type, 180 reloc_howto_type *howto, bfd_signed_vma addend) 181 { 182 bfd_reloc_status_type status = bfd_reloc_ok; 183 bfd_signed_vma old_addend = addend; 184 bfd_vma contents; 185 int size; 186 187 size = bfd_get_reloc_size (howto); 188 switch (size) 189 { 190 case 2: 191 contents = bfd_get_16 (abfd, address); 192 break; 193 case 4: 194 if (howto->src_mask != 0xffffffff) 195 /* Must be 32-bit instruction, always little-endian. */ 196 contents = bfd_getl32 (address); 197 else 198 /* Must be 32-bit data (endianness dependent). */ 199 contents = bfd_get_32 (abfd, address); 200 break; 201 case 8: 202 contents = bfd_get_64 (abfd, address); 203 break; 204 default: 205 abort (); 206 } 207 208 switch (howto->complain_on_overflow) 209 { 210 case complain_overflow_dont: 211 break; 212 case complain_overflow_signed: 213 status = aarch64_signed_overflow (addend, 214 howto->bitsize + howto->rightshift); 215 break; 216 case complain_overflow_unsigned: 217 status = aarch64_unsigned_overflow (addend, 218 howto->bitsize + howto->rightshift); 219 break; 220 case complain_overflow_bitfield: 221 default: 222 abort (); 223 } 224 225 addend >>= howto->rightshift; 226 227 switch (r_type) 228 { 229 case BFD_RELOC_AARCH64_JUMP26: 230 case BFD_RELOC_AARCH64_CALL26: 231 contents = reencode_branch_ofs_26 (contents, addend); 232 break; 233 234 case BFD_RELOC_AARCH64_BRANCH19: 235 contents = reencode_cond_branch_ofs_19 (contents, addend); 236 break; 237 238 case BFD_RELOC_AARCH64_TSTBR14: 239 contents = reencode_tst_branch_ofs_14 (contents, addend); 240 break; 241 242 case BFD_RELOC_AARCH64_LD_LO19_PCREL: 243 case BFD_RELOC_AARCH64_GOT_LD_PREL19: 244 if (old_addend & ((1 << howto->rightshift) - 1)) 245 return bfd_reloc_overflow; 246 contents = reencode_ld_lit_ofs_19 (contents, addend); 247 break; 248 249 case BFD_RELOC_AARCH64_TLSDESC_CALL: 250 break; 251 252 case BFD_RELOC_AARCH64_TLSGD_ADR_PAGE21: 253 case BFD_RELOC_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 254 case BFD_RELOC_AARCH64_TLSDESC_ADR_PAGE21: 255 case BFD_RELOC_AARCH64_ADR_GOT_PAGE: 256 case BFD_RELOC_AARCH64_ADR_LO21_PCREL: 257 case BFD_RELOC_AARCH64_ADR_HI21_PCREL: 258 case BFD_RELOC_AARCH64_ADR_HI21_NC_PCREL: 259 contents = reencode_adr_imm (contents, addend); 260 break; 261 262 case BFD_RELOC_AARCH64_TLSGD_ADD_LO12_NC: 263 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12: 264 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_HI12: 265 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12_NC: 266 case BFD_RELOC_AARCH64_TLSDESC_ADD_LO12_NC: 267 case BFD_RELOC_AARCH64_ADD_LO12: 268 /* Corresponds to: add rd, rn, #uimm12 to provide the low order 269 12 bits of the page offset following 270 BFD_RELOC_AARCH64_ADR_HI21_PCREL which computes the 271 (pc-relative) page base. */ 272 contents = reencode_add_imm (contents, addend); 273 break; 274 275 case BFD_RELOC_AARCH64_LDST8_LO12: 276 case BFD_RELOC_AARCH64_LDST16_LO12: 277 case BFD_RELOC_AARCH64_LDST32_LO12: 278 case BFD_RELOC_AARCH64_LDST64_LO12: 279 case BFD_RELOC_AARCH64_LDST128_LO12: 280 case BFD_RELOC_AARCH64_TLSDESC_LD64_LO12_NC: 281 case BFD_RELOC_AARCH64_TLSDESC_LD32_LO12_NC: 282 case BFD_RELOC_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 283 case BFD_RELOC_AARCH64_TLSIE_LD32_GOTTPREL_LO12_NC: 284 case BFD_RELOC_AARCH64_LD64_GOT_LO12_NC: 285 case BFD_RELOC_AARCH64_LD32_GOT_LO12_NC: 286 if (old_addend & ((1 << howto->rightshift) - 1)) 287 return bfd_reloc_overflow; 288 /* Used for ldr*|str* rt, [rn, #uimm12] to provide the low order 289 12 bits of the page offset following BFD_RELOC_AARCH64_ADR_HI21_PCREL 290 which computes the (pc-relative) page base. */ 291 contents = reencode_ldst_pos_imm (contents, addend); 292 break; 293 294 /* Group relocations to create high bits of a 16, 32, 48 or 64 295 bit signed data or abs address inline. Will change 296 instruction to MOVN or MOVZ depending on sign of calculated 297 value. */ 298 299 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G2: 300 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1: 301 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1_NC: 302 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0: 303 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0_NC: 304 case BFD_RELOC_AARCH64_MOVW_G0_S: 305 case BFD_RELOC_AARCH64_MOVW_G1_S: 306 case BFD_RELOC_AARCH64_MOVW_G2_S: 307 /* NOTE: We can only come here with movz or movn. */ 308 if (addend < 0) 309 { 310 /* Force use of MOVN. */ 311 addend = ~addend; 312 contents = reencode_movzn_to_movn (contents); 313 } 314 else 315 { 316 /* Force use of MOVZ. */ 317 contents = reencode_movzn_to_movz (contents); 318 } 319 /* fall through */ 320 321 /* Group relocations to create a 16, 32, 48 or 64 bit unsigned 322 data or abs address inline. */ 323 324 case BFD_RELOC_AARCH64_MOVW_G0: 325 case BFD_RELOC_AARCH64_MOVW_G0_NC: 326 case BFD_RELOC_AARCH64_MOVW_G1: 327 case BFD_RELOC_AARCH64_MOVW_G1_NC: 328 case BFD_RELOC_AARCH64_MOVW_G2: 329 case BFD_RELOC_AARCH64_MOVW_G2_NC: 330 case BFD_RELOC_AARCH64_MOVW_G3: 331 contents = reencode_movw_imm (contents, addend); 332 break; 333 334 default: 335 /* Repack simple data */ 336 if (howto->dst_mask & (howto->dst_mask + 1)) 337 return bfd_reloc_notsupported; 338 339 contents = ((contents & ~howto->dst_mask) | (addend & howto->dst_mask)); 340 break; 341 } 342 343 switch (size) 344 { 345 case 2: 346 bfd_put_16 (abfd, contents, address); 347 break; 348 case 4: 349 if (howto->dst_mask != 0xffffffff) 350 /* must be 32-bit instruction, always little-endian */ 351 bfd_putl32 (contents, address); 352 else 353 /* must be 32-bit data (endianness dependent) */ 354 bfd_put_32 (abfd, contents, address); 355 break; 356 case 8: 357 bfd_put_64 (abfd, contents, address); 358 break; 359 default: 360 abort (); 361 } 362 363 return status; 364 } 365 366 bfd_vma 367 _bfd_aarch64_elf_resolve_relocation (bfd_reloc_code_real_type r_type, 368 bfd_vma place, bfd_vma value, 369 bfd_vma addend, bfd_boolean weak_undef_p) 370 { 371 switch (r_type) 372 { 373 case BFD_RELOC_AARCH64_TLSDESC_CALL: 374 case BFD_RELOC_AARCH64_NONE: 375 break; 376 377 case BFD_RELOC_AARCH64_ADR_LO21_PCREL: 378 case BFD_RELOC_AARCH64_BRANCH19: 379 case BFD_RELOC_AARCH64_LD_LO19_PCREL: 380 case BFD_RELOC_AARCH64_16_PCREL: 381 case BFD_RELOC_AARCH64_32_PCREL: 382 case BFD_RELOC_AARCH64_64_PCREL: 383 case BFD_RELOC_AARCH64_TSTBR14: 384 if (weak_undef_p) 385 value = place; 386 value = value + addend - place; 387 break; 388 389 case BFD_RELOC_AARCH64_CALL26: 390 case BFD_RELOC_AARCH64_JUMP26: 391 value = value + addend - place; 392 break; 393 394 case BFD_RELOC_AARCH64_16: 395 case BFD_RELOC_AARCH64_32: 396 case BFD_RELOC_AARCH64_MOVW_G0_S: 397 case BFD_RELOC_AARCH64_MOVW_G1_S: 398 case BFD_RELOC_AARCH64_MOVW_G2_S: 399 case BFD_RELOC_AARCH64_MOVW_G0: 400 case BFD_RELOC_AARCH64_MOVW_G0_NC: 401 case BFD_RELOC_AARCH64_MOVW_G1: 402 case BFD_RELOC_AARCH64_MOVW_G1_NC: 403 case BFD_RELOC_AARCH64_MOVW_G2: 404 case BFD_RELOC_AARCH64_MOVW_G2_NC: 405 case BFD_RELOC_AARCH64_MOVW_G3: 406 value = value + addend; 407 break; 408 409 case BFD_RELOC_AARCH64_ADR_HI21_PCREL: 410 case BFD_RELOC_AARCH64_ADR_HI21_NC_PCREL: 411 if (weak_undef_p) 412 value = PG (place); 413 value = PG (value + addend) - PG (place); 414 break; 415 416 case BFD_RELOC_AARCH64_GOT_LD_PREL19: 417 value = value + addend - place; 418 break; 419 420 case BFD_RELOC_AARCH64_ADR_GOT_PAGE: 421 case BFD_RELOC_AARCH64_TLSDESC_ADR_PAGE21: 422 case BFD_RELOC_AARCH64_TLSGD_ADR_PAGE21: 423 case BFD_RELOC_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 424 value = PG (value + addend) - PG (place); 425 break; 426 427 case BFD_RELOC_AARCH64_ADD_LO12: 428 case BFD_RELOC_AARCH64_LD64_GOT_LO12_NC: 429 case BFD_RELOC_AARCH64_LD32_GOT_LO12_NC: 430 case BFD_RELOC_AARCH64_LDST8_LO12: 431 case BFD_RELOC_AARCH64_LDST16_LO12: 432 case BFD_RELOC_AARCH64_LDST32_LO12: 433 case BFD_RELOC_AARCH64_LDST64_LO12: 434 case BFD_RELOC_AARCH64_LDST128_LO12: 435 case BFD_RELOC_AARCH64_TLSDESC_ADD_LO12_NC: 436 case BFD_RELOC_AARCH64_TLSDESC_ADD: 437 case BFD_RELOC_AARCH64_TLSDESC_LD64_LO12_NC: 438 case BFD_RELOC_AARCH64_TLSDESC_LD32_LO12_NC: 439 case BFD_RELOC_AARCH64_TLSDESC_LDR: 440 case BFD_RELOC_AARCH64_TLSGD_ADD_LO12_NC: 441 case BFD_RELOC_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 442 case BFD_RELOC_AARCH64_TLSIE_LD32_GOTTPREL_LO12_NC: 443 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12: 444 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_LO12_NC: 445 value = PG_OFFSET (value + addend); 446 break; 447 448 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1: 449 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G1_NC: 450 value = (value + addend) & (bfd_vma) 0xffff0000; 451 break; 452 case BFD_RELOC_AARCH64_TLSLE_ADD_TPREL_HI12: 453 value = (value + addend) & (bfd_vma) 0xfff000; 454 break; 455 456 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0: 457 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G0_NC: 458 value = (value + addend) & (bfd_vma) 0xffff; 459 break; 460 461 case BFD_RELOC_AARCH64_TLSLE_MOVW_TPREL_G2: 462 value = (value + addend) & ~(bfd_vma) 0xffffffff; 463 value -= place & ~(bfd_vma) 0xffffffff; 464 break; 465 466 default: 467 break; 468 } 469 470 return value; 471 } 472 473 /* Hook called by the linker routine which adds symbols from an object 474 file. */ 475 476 bfd_boolean 477 _bfd_aarch64_elf_add_symbol_hook (bfd *abfd, struct bfd_link_info *info, 478 Elf_Internal_Sym *sym, 479 const char **namep ATTRIBUTE_UNUSED, 480 flagword *flagsp ATTRIBUTE_UNUSED, 481 asection **secp ATTRIBUTE_UNUSED, 482 bfd_vma *valp ATTRIBUTE_UNUSED) 483 { 484 if ((ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC 485 || ELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE) 486 && (abfd->flags & DYNAMIC) == 0 487 && bfd_get_flavour (info->output_bfd) == bfd_target_elf_flavour) 488 elf_tdata (info->output_bfd)->has_gnu_symbols = TRUE; 489 490 return TRUE; 491 } 492 493 /* Support for core dump NOTE sections. */ 494 495 bfd_boolean 496 _bfd_aarch64_elf_grok_prstatus (bfd *abfd, Elf_Internal_Note *note) 497 { 498 int offset; 499 size_t size; 500 501 switch (note->descsz) 502 { 503 default: 504 return FALSE; 505 506 case 392: /* sizeof(struct elf_prstatus) on Linux/arm64. */ 507 /* pr_cursig */ 508 elf_tdata (abfd)->core->signal 509 = bfd_get_16 (abfd, note->descdata + 12); 510 511 /* pr_pid */ 512 elf_tdata (abfd)->core->lwpid 513 = bfd_get_32 (abfd, note->descdata + 32); 514 515 /* pr_reg */ 516 offset = 112; 517 size = 272; 518 519 break; 520 } 521 522 /* Make a ".reg/999" section. */ 523 return _bfd_elfcore_make_pseudosection (abfd, ".reg", 524 size, note->descpos + offset); 525 } 526 527 bfd_boolean 528 _bfd_aarch64_elf_grok_psinfo (bfd *abfd, Elf_Internal_Note *note) 529 { 530 switch (note->descsz) 531 { 532 default: 533 return FALSE; 534 535 case 136: /* This is sizeof(struct elf_prpsinfo) on Linux/aarch64. */ 536 elf_tdata (abfd)->core->pid = bfd_get_32 (abfd, note->descdata + 24); 537 elf_tdata (abfd)->core->program 538 = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16); 539 elf_tdata (abfd)->core->command 540 = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80); 541 } 542 543 /* Note that for some reason, a spurious space is tacked 544 onto the end of the args in some (at least one anyway) 545 implementations, so strip it off if it exists. */ 546 547 { 548 char *command = elf_tdata (abfd)->core->command; 549 int n = strlen (command); 550 551 if (0 < n && command[n - 1] == ' ') 552 command[n - 1] = '\0'; 553 } 554 555 return TRUE; 556 } 557 558 char * 559 _bfd_aarch64_elf_write_core_note (bfd *abfd, char *buf, int *bufsiz, int note_type, 560 ...) 561 { 562 switch (note_type) 563 { 564 default: 565 return NULL; 566 567 case NT_PRPSINFO: 568 { 569 char data[136]; 570 va_list ap; 571 572 va_start (ap, note_type); 573 memset (data, 0, sizeof (data)); 574 strncpy (data + 40, va_arg (ap, const char *), 16); 575 strncpy (data + 56, va_arg (ap, const char *), 80); 576 va_end (ap); 577 578 return elfcore_write_note (abfd, buf, bufsiz, "CORE", 579 note_type, data, sizeof (data)); 580 } 581 582 case NT_PRSTATUS: 583 { 584 char data[392]; 585 va_list ap; 586 long pid; 587 int cursig; 588 const void *greg; 589 590 va_start (ap, note_type); 591 memset (data, 0, sizeof (data)); 592 pid = va_arg (ap, long); 593 bfd_put_32 (abfd, pid, data + 32); 594 cursig = va_arg (ap, int); 595 bfd_put_16 (abfd, cursig, data + 12); 596 greg = va_arg (ap, const void *); 597 memcpy (data + 112, greg, 272); 598 va_end (ap); 599 600 return elfcore_write_note (abfd, buf, bufsiz, "CORE", 601 note_type, data, sizeof (data)); 602 } 603 } 604 } 605