tools/relocate-rela.c

   1 // SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause
   2 /*
   3  * Copyright 2013 Freescale Semiconductor, Inc.
   4  *
   5  * 64-bit and little-endian target only until we need to support a different
   6  * arch that needs this.
   7  */
   8
   9 #include <elf.h>
  10 #include <errno.h>
  11 #include <inttypes.h>
  12 #include <stdarg.h>
  13 #include <stdbool.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include "compiler.h"
  18
  19 #ifndef R_AARCH64_RELATIVE
  20 #define R_AARCH64_RELATIVE      1027
  21 #endif
  22
  23 static int ei_class;
  24
  25 static uint64_t rela_start, rela_end, text_base, dyn_start;
  26
  27 static const bool debug_en;
  28
  29 static void debug(const char *fmt, ...)
  30 {
  31         va_list args;
  32
  33         if (debug_en) {
  34                 va_start(args, fmt);
  35                 vprintf(fmt, args);
  36                 va_end(args);
  37         }
  38 }
  39
  40 static bool supported_rela(Elf64_Rela *rela)
  41 {
  42         uint64_t mask = 0xffffffffULL; /* would be different on 32-bit */
  43         uint32_t type = rela->r_info & mask;
  44
  45         switch (type) {
  46         case R_AARCH64_RELATIVE:
  47                 return true;
  48         default:
  49                 fprintf(stderr, "warning: unsupported relocation type %"
  50                                 PRIu32 " at %" PRIx64 "\n",
  51                         type, rela->r_offset);
  52
  53                 return false;
  54         }
  55 }
  56
  57 static int decode_elf64(FILE *felf, char **argv)
  58 {
  59         size_t size;
  60         Elf64_Ehdr header;
  61         uint64_t section_header_base, section_header_size;
  62         uint64_t sh_addr, sh_offset, sh_size;
  63         Elf64_Half sh_index, sh_num;
  64         Elf64_Shdr *sh_table; /* Elf symbol table */
  65         int ret, i, machine;
  66         char *sh_str;
  67
  68         debug("64bit version\n");
  69
  70         /* Make sure we are at start */
  71         rewind(felf);
  72
  73         size = fread(&header, 1, sizeof(header), felf);
  74         if (size != sizeof(header)) {
  75                 fclose(felf);
  76                 return 25;
  77         }
  78
  79         machine = le16_to_cpu(header.e_machine);
  80         debug("Machine\t%d\n", machine);
  81
  82         if (machine != EM_AARCH64) {
  83                 fprintf(stderr, "%s: Not supported machine type\n", argv[0]);
  84                 return 30;
  85         }
  86
  87         text_base = le64_to_cpu(header.e_entry);
  88         section_header_base = le64_to_cpu(header.e_shoff);
  89         section_header_size = le16_to_cpu(header.e_shentsize) *
  90                               le16_to_cpu(header.e_shnum);
  91
  92         sh_table = malloc(section_header_size);
  93         if (!sh_table) {
  94                 fprintf(stderr, "%s: Cannot allocate space for section header\n",
  95                         argv[0]);
  96                 fclose(felf);
  97                 return 26;
  98         }
  99
 100         ret = fseek(felf, section_header_base, SEEK_SET);
 101         if (ret) {
 102                 fprintf(stderr, "%s: Can't set pointer to section header: %x/%lx\n",
 103                         argv[0], ret, section_header_base);
 104                 free(sh_table);
 105                 fclose(felf);
 106                 return 26;
 107         }
 108
 109         size = fread(sh_table, 1, section_header_size, felf);
 110         if (size != section_header_size) {
 111                 fprintf(stderr, "%s: Can't read section header: %lx/%lx\n",
 112                         argv[0], size, section_header_size);
 113                 free(sh_table);
 114                 fclose(felf);
 115                 return 27;
 116         }
 117
 118         sh_index = le16_to_cpu(header.e_shstrndx);
 119         sh_size = le64_to_cpu(sh_table[sh_index].sh_size);
 120         debug("e_shstrndx %x, sh_size %lx\n", sh_index, sh_size);
 121
 122         sh_str = malloc(sh_size);
 123         if (!sh_str) {
 124                 fprintf(stderr, "malloc failed\n");
 125                 free(sh_table);
 126                 fclose(felf);
 127                 return 28;
 128         }
 129
 130         /*
 131          * Specifies the byte offset from the beginning of the file
 132          * to the first byte in the section.
 133          */
 134         sh_offset = le64_to_cpu(sh_table[sh_index].sh_offset);
 135         sh_num = le16_to_cpu(header.e_shnum);
 136
 137         ret = fseek(felf, sh_offset, SEEK_SET);
 138         if (ret) {
 139                 fprintf(stderr, "Setting up sh_offset failed\n");
 140                 free(sh_str);
 141                 free(sh_table);
 142                 fclose(felf);
 143                 return 29;
 144         }
 145
 146         size = fread(sh_str, 1, sh_size, felf);
 147         if (size != sh_size) {
 148                 fprintf(stderr, "%s: Can't read section: %lx/%lx\n",
 149                         argv[0], size, sh_size);
 150                 free(sh_str);
 151                 free(sh_table);
 152                 fclose(felf);
 153                 return 30;
 154         }
 155
 156         for (i = 0; i < sh_num; i++) {
 157                 char *sh_name = sh_str + le32_to_cpu(sh_table[i].sh_name);
 158
 159                 debug("%s\n", sh_name);
 160
 161                 sh_addr = le64_to_cpu(sh_table[i].sh_addr);
 162                 sh_offset = le64_to_cpu(sh_table[i].sh_offset);
 163                 sh_size = le64_to_cpu(sh_table[i].sh_size);
 164
 165                 if (!strcmp(".rela.dyn", sh_name)) {
 166                         debug("Found section\t\".rela_dyn\"\n");
 167                         debug(" at addr\t0x%08x\n", sh_addr);
 168                         debug(" at offset\t0x%08x\n", sh_offset);
 169                         debug(" of size\t0x%08x\n", sh_size);
 170                         rela_start = sh_addr;
 171                         rela_end = rela_start + sh_size;
 172                         break;
 173                 }
 174         }
 175
 176         /* Clean up */
 177         free(sh_str);
 178         free(sh_table);
 179         fclose(felf);
 180
 181         debug("text_base\t0x%08lx\n", text_base);
 182         debug("rela_start\t0x%08lx\n", rela_start);
 183         debug("rela_end\t0x%08lx\n", rela_end);
 184
 185         if (!rela_start)
 186                 return 1;
 187
 188         return 0;
 189 }
 190
 191 static int decode_elf32(FILE *felf, char **argv)
 192 {
 193         size_t size;
 194         Elf32_Ehdr header;
 195         uint64_t section_header_base, section_header_size;
 196         uint32_t sh_addr, sh_offset, sh_size;
 197         Elf32_Half sh_index, sh_num;
 198         Elf32_Shdr *sh_table; /* Elf symbol table */
 199         int ret, i, machine;
 200         char *sh_str;
 201
 202         debug("32bit version\n");
 203
 204         /* Make sure we are at start */
 205         rewind(felf);
 206
 207         size = fread(&header, 1, sizeof(header), felf);
 208         if (size != sizeof(header)) {
 209                 fclose(felf);
 210                 return 25;
 211         }
 212
 213         machine = le16_to_cpu(header.e_machine);
 214         debug("Machine %d\n", machine);
 215
 216         if (machine != EM_MICROBLAZE) {
 217                 fprintf(stderr, "%s: Not supported machine type\n", argv[0]);
 218                 return 30;
 219         }
 220
 221         text_base = le32_to_cpu(header.e_entry);
 222         section_header_base = le32_to_cpu(header.e_shoff);
 223         section_header_size = le16_to_cpu(header.e_shentsize) *
 224                               le16_to_cpu(header.e_shnum);
 225
 226         sh_table = malloc(section_header_size);
 227         if (!sh_table) {
 228                 fprintf(stderr, "%s: Cannot allocate space for section header\n",
 229                         argv[0]);
 230                 fclose(felf);
 231                 return 26;
 232         }
 233
 234         ret = fseek(felf, section_header_base, SEEK_SET);
 235         if (ret) {
 236                 fprintf(stderr, "%s: Can't set pointer to section header: %x/%lx\n",
 237                         argv[0], ret, section_header_base);
 238                 free(sh_table);
 239                 fclose(felf);
 240                 return 26;
 241         }
 242
 243         size = fread(sh_table, 1, section_header_size, felf);
 244         if (size != section_header_size) {
 245                 fprintf(stderr, "%s: Can't read section header: %lx/%lx\n",
 246                         argv[0], size, section_header_size);
 247                 free(sh_table);
 248                 fclose(felf);
 249                 return 27;
 250         }
 251
 252         sh_index = le16_to_cpu(header.e_shstrndx);
 253         sh_size = le32_to_cpu(sh_table[sh_index].sh_size);
 254         debug("e_shstrndx %x, sh_size %lx\n", sh_index, sh_size);
 255
 256         sh_str = malloc(sh_size);
 257         if (!sh_str) {
 258                 fprintf(stderr, "malloc failed\n");
 259                 free(sh_table);
 260                 fclose(felf);
 261                 return 28;
 262         }
 263
 264         /*
 265          * Specifies the byte offset from the beginning of the file
 266          * to the first byte in the section.
 267          */
 268         sh_offset = le32_to_cpu(sh_table[sh_index].sh_offset);
 269         sh_num = le16_to_cpu(header.e_shnum);
 270
 271         ret = fseek(felf, sh_offset, SEEK_SET);
 272         if (ret) {
 273                 fprintf(stderr, "Setting up sh_offset failed\n");
 274                 free(sh_str);
 275                 free(sh_table);
 276                 fclose(felf);
 277                 return 29;
 278         }
 279
 280         size = fread(sh_str, 1, sh_size, felf);
 281         if (size != sh_size) {
 282                 fprintf(stderr, "%s: Can't read section: %lx/%x\n",
 283                         argv[0], size, sh_size);
 284                 free(sh_str);
 285                 free(sh_table);
 286                 fclose(felf);
 287                 return 30;
 288         }
 289
 290         for (i = 0; i < sh_num; i++) {
 291                 char *sh_name = sh_str + le32_to_cpu(sh_table[i].sh_name);
 292
 293                 debug("%s\n", sh_name);
 294
 295                 sh_addr = le64_to_cpu(sh_table[i].sh_addr);
 296                 sh_offset = le64_to_cpu(sh_table[i].sh_offset);
 297                 sh_size = le64_to_cpu(sh_table[i].sh_size);
 298
 299                 if (!strcmp(".rela.dyn", sh_name)) {
 300                         debug("Found section\t\".rela_dyn\"\n");
 301                         debug(" at addr\t0x%08x\n", sh_addr);
 302                         debug(" at offset\t0x%08x\n", sh_offset);
 303                         debug(" of size\t0x%08x\n", sh_size);
 304                         rela_start = sh_addr;
 305                         rela_end = rela_start + sh_size;
 306                 }
 307                 if (!strcmp(".dynsym", sh_name)) {
 308                         debug("Found section\t\".dynsym\"\n");
 309                         debug(" at addr\t0x%08x\n", sh_addr);
 310                         debug(" at offset\t0x%08x\n", sh_offset);
 311                         debug(" of size\t0x%08x\n", sh_size);
 312                         dyn_start = sh_addr;
 313                 }
 314         }
 315
 316         /* Clean up */
 317         free(sh_str);
 318         free(sh_table);
 319         fclose(felf);
 320
 321         debug("text_base\t0x%08lx\n", text_base);
 322         debug("rela_start\t0x%08lx\n", rela_start);
 323         debug("rela_end\t0x%08lx\n", rela_end);
 324         debug("dyn_start\t0x%08lx\n", dyn_start);
 325
 326         if (!rela_start)
 327                 return 1;
 328
 329         return 0;
 330 }
 331
 332 static int decode_elf(char **argv)
 333 {
 334         FILE *felf;
 335         size_t size;
 336         unsigned char e_ident[EI_NIDENT];
 337
 338         felf = fopen(argv[2], "r+b");
 339         if (!felf) {
 340                 fprintf(stderr, "%s: Cannot open %s: %s\n",
 341                         argv[0], argv[5], strerror(errno));
 342                 return 2;
 343         }
 344
 345         size = fread(e_ident, 1, EI_NIDENT, felf);
 346         if (size != EI_NIDENT) {
 347                 fclose(felf);
 348                 return 25;
 349         }
 350
 351         /* Check if this is really ELF file */
 352         if (e_ident[0] != 0x7f &&
 353             e_ident[1] != 'E' &&
 354             e_ident[2] != 'L' &&
 355             e_ident[3] != 'F') {
 356                 fclose(felf);
 357                 return 1;
 358         }
 359
 360         ei_class = e_ident[4];
 361         debug("EI_CLASS(1=32bit, 2=64bit) %d\n", ei_class);
 362
 363         if (ei_class == 2)
 364                 return decode_elf64(felf, argv);
 365
 366         return decode_elf32(felf, argv);
 367 }
 368
 369 static int rela_elf64(char **argv, FILE *f)
 370 {
 371         int i, num;
 372
 373         if ((rela_end - rela_start) % sizeof(Elf64_Rela)) {
 374                 fprintf(stderr, "%s: rela size isn't a multiple of Elf64_Rela\n", argv[0]);
 375                 return 3;
 376         }
 377
 378         num = (rela_end - rela_start) / sizeof(Elf64_Rela);
 379
 380         for (i = 0; i < num; i++) {
 381                 Elf64_Rela rela, swrela;
 382                 uint64_t pos = rela_start + sizeof(Elf64_Rela) * i;
 383                 uint64_t addr;
 384
 385                 if (fseek(f, pos, SEEK_SET) < 0) {
 386                         fprintf(stderr, "%s: %s: seek to %" PRIx64
 387                                         " failed: %s\n",
 388                                 argv[0], argv[1], pos, strerror(errno));
 389                 }
 390
 391                 if (fread(&rela, sizeof(rela), 1, f) != 1) {
 392                         fprintf(stderr, "%s: %s: read rela failed at %"
 393                                         PRIx64 "\n",
 394                                 argv[0], argv[1], pos);
 395                         return 4;
 396                 }
 397
 398                 swrela.r_offset = le64_to_cpu(rela.r_offset);
 399                 swrela.r_info = le64_to_cpu(rela.r_info);
 400                 swrela.r_addend = le64_to_cpu(rela.r_addend);
 401
 402                 if (!supported_rela(&swrela))
 403                         continue;
 404
 405                 debug("Rela %" PRIx64 " %" PRIu64 " %" PRIx64 "\n",
 406                       swrela.r_offset, swrela.r_info, swrela.r_addend);
 407
 408                 if (swrela.r_offset < text_base) {
 409                         fprintf(stderr, "%s: %s: bad rela at %" PRIx64 "\n",
 410                                 argv[0], argv[1], pos);
 411                         return 4;
 412                 }
 413
 414                 addr = swrela.r_offset - text_base;
 415
 416                 if (fseek(f, addr, SEEK_SET) < 0) {
 417                         fprintf(stderr, "%s: %s: seek to %"
 418                                         PRIx64 " failed: %s\n",
 419                                 argv[0], argv[1], addr, strerror(errno));
 420                 }
 421
 422                 if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
 423                         fprintf(stderr, "%s: %s: write failed at %" PRIx64 "\n",
 424                                 argv[0], argv[1], addr);
 425                         return 4;
 426                 }
 427         }
 428
 429         return 0;
 430 }
 431
 432 static bool supported_rela32(Elf32_Rela *rela, uint32_t *type)
 433 {
 434         uint32_t mask = 0xffULL; /* would be different on 32-bit */
 435         *type = rela->r_info & mask;
 436
 437         debug("Type:\t");
 438
 439         switch (*type) {
 440         case R_MICROBLAZE_32:
 441                 debug("R_MICROBLAZE_32\n");
 442                 return true;
 443         case R_MICROBLAZE_GLOB_DAT:
 444                 debug("R_MICROBLAZE_GLOB_DAT\n");
 445                 return true;
 446         case R_MICROBLAZE_NONE:
 447                 debug("R_MICROBLAZE_NONE - ignoring - do nothing\n");
 448                 return false;
 449         case R_MICROBLAZE_REL:
 450                 debug("R_MICROBLAZE_REL\n");
 451                 return true;
 452         default:
 453                 fprintf(stderr, "warning: unsupported relocation type %"
 454                         PRIu32 " at %" PRIx32 "\n", *type, rela->r_offset);
 455
 456                 return false;
 457         }
 458 }
 459
 460 static int rela_elf32(char **argv, FILE *f)
 461 {
 462         int i, num, index;
 463         uint32_t value, type;
 464
 465         if ((rela_end - rela_start) % sizeof(Elf32_Rela)) {
 466                 fprintf(stderr, "%s: rela size isn't a multiple of Elf32_Rela\n", argv[0]);
 467                 return 3;
 468         }
 469
 470         num = (rela_end - rela_start) / sizeof(Elf32_Rela);
 471
 472         debug("Number of entries: %u\n", num);
 473
 474         for (i = 0; i < num; i++) {
 475                 Elf32_Rela rela, swrela;
 476                 Elf32_Sym symbols;
 477                 uint32_t pos = rela_start + sizeof(Elf32_Rela) * i;
 478                 uint32_t addr, pos_dyn;
 479
 480                 debug("\nPossition:\t%d/0x%x\n", i, pos);
 481
 482                 if (fseek(f, pos, SEEK_SET) < 0) {
 483                         fprintf(stderr, "%s: %s: seek to %" PRIx32
 484                                         " failed: %s\n",
 485                                 argv[0], argv[1], pos, strerror(errno));
 486                 }
 487
 488                 if (fread(&rela, sizeof(rela), 1, f) != 1) {
 489                         fprintf(stderr, "%s: %s: read rela failed at %"
 490                                         PRIx32 "\n",
 491                                 argv[0], argv[1], pos);
 492                         return 4;
 493                 }
 494
 495                 debug("Rela:\toffset:\t%" PRIx32 " r_info:\t%"
 496                       PRIu32 " r_addend:\t%" PRIx32 "\n",
 497                       rela.r_offset, rela.r_info, rela.r_addend);
 498
 499                 swrela.r_offset = le32_to_cpu(rela.r_offset);
 500                 swrela.r_info = le32_to_cpu(rela.r_info);
 501                 swrela.r_addend = le32_to_cpu(rela.r_addend);
 502
 503                 debug("SWRela:\toffset:\t%" PRIx32 " r_info:\t%"
 504                       PRIu32 " r_addend:\t%" PRIx32 "\n",
 505                       swrela.r_offset, swrela.r_info, swrela.r_addend);
 506
 507                 if (!supported_rela32(&swrela, &type))
 508                         continue;
 509
 510                 if (swrela.r_offset < text_base) {
 511                         fprintf(stderr, "%s: %s: bad rela at %" PRIx32 "\n",
 512                                 argv[0], argv[1], pos);
 513                         return 4;
 514                 }
 515
 516                 addr = swrela.r_offset - text_base;
 517
 518                 debug("Addr:\t0x%" PRIx32 "\n", addr);
 519
 520                 switch (type) {
 521                 case R_MICROBLAZE_REL:
 522                         if (fseek(f, addr, SEEK_SET) < 0) {
 523                                 fprintf(stderr, "%s: %s: seek to %"
 524                                         PRIx32 " failed: %s\n",
 525                                         argv[0], argv[1], addr, strerror(errno));
 526                                 return 5;
 527                         }
 528
 529                         debug("Write addend\n");
 530
 531                         if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
 532                                 fprintf(stderr, "%s: %s: write failed at %" PRIx32 "\n",
 533                                         argv[0], argv[1], addr);
 534                                 return 4;
 535                         }
 536                         break;
 537                 case R_MICROBLAZE_32:
 538                 case R_MICROBLAZE_GLOB_DAT:
 539                         /* global symbols read it and add reloc offset */
 540                         index = swrela.r_info >> 8;
 541                         pos_dyn = dyn_start + sizeof(Elf32_Sym) * index;
 542
 543                         debug("Index:\t%d\n", index);
 544                         debug("Pos_dyn:\t0x%x\n", pos_dyn);
 545
 546                         if (fseek(f, pos_dyn, SEEK_SET) < 0) {
 547                                 fprintf(stderr, "%s: %s: seek to %"
 548                                         PRIx32 " failed: %s\n",
 549                                         argv[0], argv[1], pos_dyn, strerror(errno));
 550                                 return 5;
 551                         }
 552
 553                         if (fread(&symbols, sizeof(symbols), 1, f) != 1) {
 554                                 fprintf(stderr, "%s: %s: read symbols failed at %"
 555                                                 PRIx32 "\n",
 556                                         argv[0], argv[1], pos_dyn);
 557                                 return 4;
 558                         }
 559
 560                         debug("Symbol description:\n");
 561                         debug(" st_name:\t0x%x\n", symbols.st_name);
 562                         debug(" st_value:\t0x%x\n", symbols.st_value);
 563                         debug(" st_size:\t0x%x\n", symbols.st_size);
 564
 565                         value = swrela.r_addend + symbols.st_value;
 566
 567                         debug("Value:\t0x%x\n", value);
 568
 569                         if (fseek(f, addr, SEEK_SET) < 0) {
 570                                 fprintf(stderr, "%s: %s: seek to %"
 571                                         PRIx32 " failed: %s\n",
 572                                         argv[0], argv[1], addr, strerror(errno));
 573                                 return 5;
 574                         }
 575
 576                         if (fwrite(&value, sizeof(rela.r_addend), 1, f) != 1) {
 577                                 fprintf(stderr, "%s: %s: write failed at %" PRIx32 "\n",
 578                                         argv[0], argv[1], addr);
 579                                 return 4;
 580                         }
 581
 582                         break;
 583                 case R_MICROBLAZE_NONE:
 584                         debug("R_MICROBLAZE_NONE - skip\n");
 585                         break;
 586                 default:
 587                         fprintf(stderr, "warning: unsupported relocation type %"
 588                                 PRIu32 " at %" PRIx32 "\n",
 589                                 type, rela.r_offset);
 590                 }
 591         }
 592
 593         return 0;
 594 }
 595
 596 int main(int argc, char **argv)
 597 {
 598         FILE *f;
 599         int ret;
 600         uint64_t file_size;
 601
 602         if (argc != 3) {
 603                 fprintf(stderr, "Statically apply ELF rela relocations\n");
 604                 fprintf(stderr, "Usage: %s <bin file> <u-boot ELF>\n",
 605                         argv[0]);
 606                 return 1;
 607         }
 608
 609         ret = decode_elf(argv);
 610         if (ret) {
 611                 fprintf(stderr, "ELF decoding failed\n");
 612                 return ret;
 613         }
 614
 615         if (rela_start > rela_end || rela_start < text_base) {
 616                 fprintf(stderr, "%s: bad rela bounds\n", argv[0]);
 617                 return 3;
 618         }
 619
 620         rela_start -= text_base;
 621         rela_end -= text_base;
 622         dyn_start -= text_base;
 623
 624         f = fopen(argv[1], "r+b");
 625         if (!f) {
 626                 fprintf(stderr, "%s: Cannot open %s: %s\n",
 627                         argv[0], argv[1], strerror(errno));
 628                 return 2;
 629         }
 630
 631         fseek(f, 0, SEEK_END);
 632         file_size = ftell(f);
 633         rewind(f);
 634
 635         if (rela_end > file_size) {
 636                 // Most likely compiler inserted some section that didn't get
 637                 // objcopy-ed into the final binary
 638                 rela_end = file_size;
 639         }
 640
 641         if (ei_class == 2)
 642                 ret = rela_elf64(argv, f);
 643         else
 644                 ret = rela_elf32(argv, f);
 645
 646         if (fclose(f) < 0) {
 647                 fprintf(stderr, "%s: %s: close failed: %s\n",
 648                         argv[0], argv[1], strerror(errno));
 649                 return 4;
 650         }
 651
 652         return ret;
 653 }