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 #ifdef R_AARCH64_RELATIVE
  47         case R_AARCH64_RELATIVE:
  48                 return true;
  49 #endif
  50         default:
  51                 fprintf(stderr, "warning: unsupported relocation type %"
  52                                 PRIu32 " at %" PRIx64 "\n",
  53                         type, rela->r_offset);
  54
  55                 return false;
  56         }
  57 }
  58
  59 static int decode_elf64(FILE *felf, char **argv)
  60 {
  61         size_t size;
  62         Elf64_Ehdr header;
  63         uint64_t section_header_base, section_header_size, sh_offset, sh_size;
  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 = 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 = header.e_entry;
  88         section_header_base = header.e_shoff;
  89         section_header_size = header.e_shentsize * header.e_shnum;
  90
  91         sh_table = malloc(section_header_size);
  92         if (!sh_table) {
  93                 fprintf(stderr, "%s: Cannot allocate space for section header\n",
  94                         argv[0]);
  95                 fclose(felf);
  96                 return 26;
  97         }
  98
  99         ret = fseek(felf, section_header_base, SEEK_SET);
 100         if (ret) {
 101                 fprintf(stderr, "%s: Can't set pointer to section header: %x/%lx\n",
 102                         argv[0], ret, section_header_base);
 103                 free(sh_table);
 104                 fclose(felf);
 105                 return 26;
 106         }
 107
 108         size = fread(sh_table, 1, section_header_size, felf);
 109         if (size != section_header_size) {
 110                 fprintf(stderr, "%s: Can't read section header: %lx/%lx\n",
 111                         argv[0], size, section_header_size);
 112                 free(sh_table);
 113                 fclose(felf);
 114                 return 27;
 115         }
 116
 117         sh_size = sh_table[header.e_shstrndx].sh_size;
 118         debug("e_shstrndx\t0x%08x\n", header.e_shstrndx);
 119         debug("sh_size\t\t0x%08lx\n", sh_size);
 120
 121         sh_str = malloc(sh_size);
 122         if (!sh_str) {
 123                 fprintf(stderr, "malloc failed\n");
 124                 free(sh_table);
 125                 fclose(felf);
 126                 return 28;
 127         }
 128
 129         /*
 130          * Specifies the byte offset from the beginning of the file
 131          * to the first byte in the section.
 132          */
 133         sh_offset = sh_table[header.e_shstrndx].sh_offset;
 134
 135         debug("sh_offset\t0x%08x\n", 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 < header.e_shnum; i++) {
 157                 /* fprintf(stderr, "%s\n", sh_str + sh_table[i].sh_name); Debug only */
 158                 if (!strcmp(".rela.dyn", (sh_str + sh_table[i].sh_name))) {
 159                         debug("Found section\t\".rela_dyn\"\n");
 160                         debug(" at addr\t0x%08x\n",
 161                               (unsigned int)sh_table[i].sh_addr);
 162                         debug(" at offset\t0x%08x\n",
 163                               (unsigned int)sh_table[i].sh_offset);
 164                         debug(" of size\t0x%08x\n",
 165                               (unsigned int)sh_table[i].sh_size);
 166                         rela_start = sh_table[i].sh_addr;
 167                         rela_end = rela_start + sh_table[i].sh_size;
 168                         break;
 169                 }
 170         }
 171
 172         /* Clean up */
 173         free(sh_str);
 174         free(sh_table);
 175         fclose(felf);
 176
 177         debug("text_base\t0x%08lx\n", text_base);
 178         debug("rela_start\t0x%08lx\n", rela_start);
 179         debug("rela_end\t0x%08lx\n", rela_end);
 180
 181         if (!rela_start)
 182                 return 1;
 183
 184         return 0;
 185 }
 186
 187 static int decode_elf32(FILE *felf, char **argv)
 188 {
 189         size_t size;
 190         Elf32_Ehdr header;
 191         uint64_t section_header_base, section_header_size, sh_offset, sh_size;
 192         Elf32_Shdr *sh_table; /* Elf symbol table */
 193         int ret, i, machine;
 194         char *sh_str;
 195
 196         debug("32bit version\n");
 197
 198         /* Make sure we are at start */
 199         rewind(felf);
 200
 201         size = fread(&header, 1, sizeof(header), felf);
 202         if (size != sizeof(header)) {
 203                 fclose(felf);
 204                 return 25;
 205         }
 206
 207         machine = header.e_machine;
 208         debug("Machine %d\n", machine);
 209
 210         if (machine != EM_MICROBLAZE) {
 211                 fprintf(stderr, "%s: Not supported machine type\n", argv[0]);
 212                 return 30;
 213         }
 214
 215         text_base = header.e_entry;
 216         section_header_base = header.e_shoff;
 217
 218         debug("Section header base %x\n", section_header_base);
 219
 220         section_header_size = header.e_shentsize * header.e_shnum;
 221
 222         debug("Section header size %d\n", section_header_size);
 223
 224         sh_table = malloc(section_header_size);
 225         if (!sh_table) {
 226                 fprintf(stderr, "%s: Cannot allocate space for section header\n",
 227                         argv[0]);
 228                 fclose(felf);
 229                 return 26;
 230         }
 231
 232         ret = fseek(felf, section_header_base, SEEK_SET);
 233         if (ret) {
 234                 fprintf(stderr, "%s: Can't set pointer to section header: %x/%lx\n",
 235                         argv[0], ret, section_header_base);
 236                 free(sh_table);
 237                 fclose(felf);
 238                 return 26;
 239         }
 240
 241         size = fread(sh_table, 1, section_header_size, felf);
 242         if (size != section_header_size) {
 243                 fprintf(stderr, "%s: Can't read section header: %lx/%lx\n",
 244                         argv[0], size, section_header_size);
 245                 free(sh_table);
 246                 fclose(felf);
 247                 return 27;
 248         }
 249
 250         sh_size = sh_table[header.e_shstrndx].sh_size;
 251         debug("e_shstrndx %x, sh_size %lx\n", header.e_shstrndx, sh_size);
 252
 253         sh_str = malloc(sh_size);
 254         if (!sh_str) {
 255                 fprintf(stderr, "malloc failed\n");
 256                 free(sh_table);
 257                 fclose(felf);
 258                 return 28;
 259         }
 260
 261         /*
 262          * Specifies the byte offset from the beginning of the file
 263          * to the first byte in the section.
 264          */
 265         sh_offset = sh_table[header.e_shstrndx].sh_offset;
 266
 267         debug("sh_offset %x\n", header.e_shnum);
 268
 269         ret = fseek(felf, sh_offset, SEEK_SET);
 270         if (ret) {
 271                 fprintf(stderr, "Setting up sh_offset failed\n");
 272                 free(sh_str);
 273                 free(sh_table);
 274                 fclose(felf);
 275                 return 29;
 276         }
 277
 278         size = fread(sh_str, 1, sh_size, felf);
 279         if (size != sh_size) {
 280                 fprintf(stderr, "%s: Can't read section: %lx/%lx\n",
 281                         argv[0], size, sh_size);
 282                 free(sh_str);
 283                 free(sh_table);
 284                 fclose(felf);
 285                 return 30;
 286         }
 287
 288         for (i = 0; i < header.e_shnum; i++) {
 289                 debug("%s\n", sh_str + sh_table[i].sh_name);
 290                 if (!strcmp(".rela.dyn", (sh_str + sh_table[i].sh_name))) {
 291                         debug("Found section\t\".rela_dyn\"\n");
 292                         debug(" at addr\t0x%08x\n", (unsigned int)sh_table[i].sh_addr);
 293                         debug(" at offset\t0x%08x\n", (unsigned int)sh_table[i].sh_offset);
 294                         debug(" of size\t0x%08x\n", (unsigned int)sh_table[i].sh_size);
 295                         rela_start = sh_table[i].sh_addr;
 296                         rela_end = rela_start + sh_table[i].sh_size;
 297                 }
 298                 if (!strcmp(".dynsym", (sh_str + sh_table[i].sh_name))) {
 299                         debug("Found section\t\".dynsym\"\n");
 300                         debug(" at addr\t0x%08x\n", (unsigned int)sh_table[i].sh_addr);
 301                         debug(" at offset\t0x%08x\n", (unsigned int)sh_table[i].sh_offset);
 302                         debug(" of size\t0x%08x\n", (unsigned int)sh_table[i].sh_size);
 303                         dyn_start = sh_table[i].sh_addr;
 304                 }
 305         }
 306
 307         /* Clean up */
 308         free(sh_str);
 309         free(sh_table);
 310         fclose(felf);
 311
 312         debug("text_base\t0x%08lx\n", text_base);
 313         debug("rela_start\t0x%08lx\n", rela_start);
 314         debug("rela_end\t0x%08lx\n", rela_end);
 315         debug("dyn_start\t0x%08lx\n", dyn_start);
 316
 317         if (!rela_start)
 318                 return 1;
 319
 320         return 0;
 321 }
 322
 323 static int decode_elf(char **argv)
 324 {
 325         FILE *felf;
 326         size_t size;
 327         unsigned char e_ident[EI_NIDENT];
 328
 329         felf = fopen(argv[2], "r+b");
 330         if (!felf) {
 331                 fprintf(stderr, "%s: Cannot open %s: %s\n",
 332                         argv[0], argv[5], strerror(errno));
 333                 return 2;
 334         }
 335
 336         size = fread(e_ident, 1, EI_NIDENT, felf);
 337         if (size != EI_NIDENT) {
 338                 fclose(felf);
 339                 return 25;
 340         }
 341
 342         /* Check if this is really ELF file */
 343         if (e_ident[0] != 0x7f &&
 344             e_ident[1] != 'E' &&
 345             e_ident[2] != 'L' &&
 346             e_ident[3] != 'F') {
 347                 fclose(felf);
 348                 return 1;
 349         }
 350
 351         ei_class = e_ident[4];
 352         debug("EI_CLASS(1=32bit, 2=64bit) %d\n", ei_class);
 353
 354         if (ei_class == 2)
 355                 return decode_elf64(felf, argv);
 356
 357         return decode_elf32(felf, argv);
 358 }
 359
 360 static int rela_elf64(char **argv, FILE *f)
 361 {
 362         int i, num;
 363
 364         if ((rela_end - rela_start) % sizeof(Elf64_Rela)) {
 365                 fprintf(stderr, "%s: rela size isn't a multiple of Elf64_Rela\n", argv[0]);
 366                 return 3;
 367         }
 368
 369         num = (rela_end - rela_start) / sizeof(Elf64_Rela);
 370
 371         for (i = 0; i < num; i++) {
 372                 Elf64_Rela rela, swrela;
 373                 uint64_t pos = rela_start + sizeof(Elf64_Rela) * i;
 374                 uint64_t addr;
 375
 376                 if (fseek(f, pos, SEEK_SET) < 0) {
 377                         fprintf(stderr, "%s: %s: seek to %" PRIx64
 378                                         " failed: %s\n",
 379                                 argv[0], argv[1], pos, strerror(errno));
 380                 }
 381
 382                 if (fread(&rela, sizeof(rela), 1, f) != 1) {
 383                         fprintf(stderr, "%s: %s: read rela failed at %"
 384                                         PRIx64 "\n",
 385                                 argv[0], argv[1], pos);
 386                         return 4;
 387                 }
 388
 389                 swrela.r_offset = cpu_to_le64(rela.r_offset);
 390                 swrela.r_info = cpu_to_le64(rela.r_info);
 391                 swrela.r_addend = cpu_to_le64(rela.r_addend);
 392
 393                 if (!supported_rela(&swrela))
 394                         continue;
 395
 396                 debug("Rela %" PRIx64 " %" PRIu64 " %" PRIx64 "\n",
 397                       swrela.r_offset, swrela.r_info, swrela.r_addend);
 398
 399                 if (swrela.r_offset < text_base) {
 400                         fprintf(stderr, "%s: %s: bad rela at %" PRIx64 "\n",
 401                                 argv[0], argv[1], pos);
 402                         return 4;
 403                 }
 404
 405                 addr = swrela.r_offset - text_base;
 406
 407                 if (fseek(f, addr, SEEK_SET) < 0) {
 408                         fprintf(stderr, "%s: %s: seek to %"
 409                                         PRIx64 " failed: %s\n",
 410                                 argv[0], argv[1], addr, strerror(errno));
 411                 }
 412
 413                 if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
 414                         fprintf(stderr, "%s: %s: write failed at %" PRIx64 "\n",
 415                                 argv[0], argv[1], addr);
 416                         return 4;
 417                 }
 418         }
 419
 420         return 0;
 421 }
 422
 423 static bool supported_rela32(Elf32_Rela *rela, uint32_t *type)
 424 {
 425         uint32_t mask = 0xffULL; /* would be different on 32-bit */
 426         *type = rela->r_info & mask;
 427
 428         debug("Type:\t");
 429
 430         switch (*type) {
 431         case R_MICROBLAZE_32:
 432                 debug("R_MICROBLAZE_32\n");
 433                 return true;
 434         case R_MICROBLAZE_GLOB_DAT:
 435                 debug("R_MICROBLAZE_GLOB_DAT\n");
 436                 return true;
 437         case R_MICROBLAZE_NONE:
 438                 debug("R_MICROBLAZE_NONE - ignoring - do nothing\n");
 439                 return false;
 440         case R_MICROBLAZE_REL:
 441                 debug("R_MICROBLAZE_REL\n");
 442                 return true;
 443         default:
 444                 fprintf(stderr, "warning: unsupported relocation type %"
 445                         PRIu32 " at %" PRIx32 "\n", *type, rela->r_offset);
 446
 447                 return false;
 448         }
 449 }
 450
 451 static int rela_elf32(char **argv, FILE *f)
 452 {
 453         int i, num, index;
 454         uint32_t value, type;
 455
 456         if ((rela_end - rela_start) % sizeof(Elf32_Rela)) {
 457                 fprintf(stderr, "%s: rela size isn't a multiple of Elf32_Rela\n", argv[0]);
 458                 return 3;
 459         }
 460
 461         num = (rela_end - rela_start) / sizeof(Elf32_Rela);
 462
 463         debug("Number of entries: %u\n", num);
 464
 465         for (i = 0; i < num; i++) {
 466                 Elf32_Rela rela, swrela;
 467                 Elf32_Sym symbols;
 468                 uint32_t pos = rela_start + sizeof(Elf32_Rela) * i;
 469                 uint32_t addr, pos_dyn;
 470
 471                 debug("\nPossition:\t%d/0x%x\n", i, pos);
 472
 473                 if (fseek(f, pos, SEEK_SET) < 0) {
 474                         fprintf(stderr, "%s: %s: seek to %" PRIx32
 475                                         " failed: %s\n",
 476                                 argv[0], argv[1], pos, strerror(errno));
 477                 }
 478
 479                 if (fread(&rela, sizeof(rela), 1, f) != 1) {
 480                         fprintf(stderr, "%s: %s: read rela failed at %"
 481                                         PRIx32 "\n",
 482                                 argv[0], argv[1], pos);
 483                         return 4;
 484                 }
 485
 486                 debug("Rela:\toffset:\t%" PRIx32 " r_info:\t%"
 487                       PRIu32 " r_addend:\t%" PRIx32 "\n",
 488                       rela.r_offset, rela.r_info, rela.r_addend);
 489
 490                 swrela.r_offset = cpu_to_le32(rela.r_offset);
 491                 swrela.r_info = cpu_to_le32(rela.r_info);
 492                 swrela.r_addend = cpu_to_le32(rela.r_addend);
 493
 494                 debug("SWRela:\toffset:\t%" PRIx32 " r_info:\t%"
 495                       PRIu32 " r_addend:\t%" PRIx32 "\n",
 496                       swrela.r_offset, swrela.r_info, swrela.r_addend);
 497
 498                 if (!supported_rela32(&swrela, &type))
 499                         continue;
 500
 501                 if (swrela.r_offset < text_base) {
 502                         fprintf(stderr, "%s: %s: bad rela at %" PRIx32 "\n",
 503                                 argv[0], argv[1], pos);
 504                         return 4;
 505                 }
 506
 507                 addr = swrela.r_offset - text_base;
 508
 509                 debug("Addr:\t0x%" PRIx32 "\n", addr);
 510
 511                 switch (type) {
 512                 case R_MICROBLAZE_REL:
 513                         if (fseek(f, addr, SEEK_SET) < 0) {
 514                                 fprintf(stderr, "%s: %s: seek to %"
 515                                         PRIx32 " failed: %s\n",
 516                                         argv[0], argv[1], addr, strerror(errno));
 517                                 return 5;
 518                         }
 519
 520                         debug("Write addend\n");
 521
 522                         if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
 523                                 fprintf(stderr, "%s: %s: write failed at %" PRIx32 "\n",
 524                                         argv[0], argv[1], addr);
 525                                 return 4;
 526                         }
 527                         break;
 528                 case R_MICROBLAZE_32:
 529                 case R_MICROBLAZE_GLOB_DAT:
 530                         /* global symbols read it and add reloc offset */
 531                         index = swrela.r_info >> 8;
 532                         pos_dyn = dyn_start + sizeof(Elf32_Sym) * index;
 533
 534                         debug("Index:\t%d\n", index);
 535                         debug("Pos_dyn:\t0x%x\n", pos_dyn);
 536
 537                         if (fseek(f, pos_dyn, SEEK_SET) < 0) {
 538                                 fprintf(stderr, "%s: %s: seek to %"
 539                                         PRIx32 " failed: %s\n",
 540                                         argv[0], argv[1], pos_dyn, strerror(errno));
 541                                 return 5;
 542                         }
 543
 544                         if (fread(&symbols, sizeof(symbols), 1, f) != 1) {
 545                                 fprintf(stderr, "%s: %s: read symbols failed at %"
 546                                                 PRIx32 "\n",
 547                                         argv[0], argv[1], pos_dyn);
 548                                 return 4;
 549                         }
 550
 551                         debug("Symbol description:\n");
 552                         debug(" st_name:\t0x%x\n", symbols.st_name);
 553                         debug(" st_value:\t0x%x\n", symbols.st_value);
 554                         debug(" st_size:\t0x%x\n", symbols.st_size);
 555
 556                         value = swrela.r_addend + symbols.st_value;
 557
 558                         debug("Value:\t0x%x\n", value);
 559
 560                         if (fseek(f, addr, SEEK_SET) < 0) {
 561                                 fprintf(stderr, "%s: %s: seek to %"
 562                                         PRIx32 " failed: %s\n",
 563                                         argv[0], argv[1], addr, strerror(errno));
 564                                 return 5;
 565                         }
 566
 567                         if (fwrite(&value, sizeof(rela.r_addend), 1, f) != 1) {
 568                                 fprintf(stderr, "%s: %s: write failed at %" PRIx32 "\n",
 569                                         argv[0], argv[1], addr);
 570                                 return 4;
 571                         }
 572
 573                         break;
 574                 case R_MICROBLAZE_NONE:
 575                         debug("R_MICROBLAZE_NONE - skip\n");
 576                         break;
 577                 default:
 578                         fprintf(stderr, "warning: unsupported relocation type %"
 579                                 PRIu32 " at %" PRIx32 "\n",
 580                                 type, rela.r_offset);
 581                 }
 582         }
 583
 584         return 0;
 585 }
 586
 587 int main(int argc, char **argv)
 588 {
 589         FILE *f;
 590         int ret;
 591         uint64_t file_size;
 592
 593         if (argc != 3) {
 594                 fprintf(stderr, "Statically apply ELF rela relocations\n");
 595                 fprintf(stderr, "Usage: %s <bin file> <u-boot ELF>\n",
 596                         argv[0]);
 597                 return 1;
 598         }
 599
 600         ret = decode_elf(argv);
 601         if (ret) {
 602                 fprintf(stderr, "ELF decoding failed\n");
 603                 return ret;
 604         }
 605
 606         if (rela_start > rela_end || rela_start < text_base) {
 607                 fprintf(stderr, "%s: bad rela bounds\n", argv[0]);
 608                 return 3;
 609         }
 610
 611         rela_start -= text_base;
 612         rela_end -= text_base;
 613         dyn_start -= text_base;
 614
 615         f = fopen(argv[1], "r+b");
 616         if (!f) {
 617                 fprintf(stderr, "%s: Cannot open %s: %s\n",
 618                         argv[0], argv[1], strerror(errno));
 619                 return 2;
 620         }
 621
 622         fseek(f, 0, SEEK_END);
 623         file_size = ftell(f);
 624         rewind(f);
 625
 626         if (rela_end > file_size) {
 627                 // Most likely compiler inserted some section that didn't get
 628                 // objcopy-ed into the final binary
 629                 rela_end = file_size;
 630         }
 631
 632         if (ei_class == 2)
 633                 ret = rela_elf64(argv, f);
 634         else
 635                 ret = rela_elf32(argv, f);
 636
 637         if (fclose(f) < 0) {
 638                 fprintf(stderr, "%s: %s: close failed: %s\n",
 639                         argv[0], argv[1], strerror(errno));
 640                 return 4;
 641         }
 642
 643         return ret;
 644 }