src/system/runtime_loader/runtime_loader.cpp

   1 /*
   2  * Copyright 2005-2009, Axel Dörfler, axeld@pinc-software.de.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Copyright 2002, Manuel J. Petit. All rights reserved.
   6  * Distributed under the terms of the NewOS License.
   7  */
   8
   9
  10 #include "runtime_loader_private.h"
  11
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include <sys/stat.h>
  15
  16 #include <algorithm>
  17
  18 #include <ByteOrder.h>
  19
  20 #include <directories.h>
  21 #include <find_directory_private.h>
  22 #include <image_defs.h>
  23 #include <syscalls.h>
  24 #include <user_runtime.h>
  25 #include <vm_defs.h>
  26
  27 #include "elf_symbol_lookup.h"
  28 #include "pe.h"
  29
  30
  31 struct user_space_program_args *gProgramArgs;
  32 void *__gCommPageAddress;
  33 void *__dso_handle;
  34
  35 int32 __gCPUCount = 1;
  36
  37 const directory_which kLibraryDirectories[] = {
  38         B_SYSTEM_LIB_DIRECTORY,
  39         B_SYSTEM_NONPACKAGED_LIB_DIRECTORY,
  40         B_USER_LIB_DIRECTORY,
  41         B_USER_NONPACKAGED_LIB_DIRECTORY
  42 };
  43
  44
  45 static const char *
  46 search_path_for_type(image_type type)
  47 {
  48         const char *path = NULL;
  49
  50         // TODO: The *PATH variables should not include the standard system paths.
  51         // Instead those paths should always be used after the directories specified
  52         // via the variables.
  53         switch (type) {
  54                 case B_APP_IMAGE:
  55                         path = getenv("PATH");
  56                         break;
  57                 case B_LIBRARY_IMAGE:
  58                         path = getenv("LIBRARY_PATH");
  59                         break;
  60                 case B_ADD_ON_IMAGE:
  61                         path = getenv("ADDON_PATH");
  62                         break;
  63
  64                 default:
  65                         return NULL;
  66         }
  67
  68         if (path != NULL)
  69                 return path;
  70
  71         // The environment variables may not have been set yet - in that case,
  72         // we're returning some useful defaults.
  73         // Since the kernel does not set any variables, this is also needed
  74         // to start the root shell.
  75
  76         // TODO: The user specific paths should not be used by default.
  77         switch (type) {
  78                 case B_APP_IMAGE:
  79                         return kUserNonpackagedBinDirectory
  80                                 ":" kUserBinDirectory
  81                                                 // TODO: Remove!
  82                                 ":" kSystemNonpackagedBinDirectory
  83                                 ":" kGlobalBinDirectory
  84                                 ":" kSystemAppsDirectory
  85                                 ":" kSystemPreferencesDirectory;
  86
  87                 case B_LIBRARY_IMAGE:
  88                         return kAppLocalLibDirectory
  89                                 ":" kUserNonpackagedLibDirectory
  90                                 ":" kUserLibDirectory
  91                                         // TODO: Remove!
  92                                 ":" kSystemNonpackagedLibDirectory
  93                                 ":" kSystemLibDirectory;
  94
  95                 case B_ADD_ON_IMAGE:
  96                         return kAppLocalAddonsDirectory
  97                                 ":" kUserNonpackagedAddonsDirectory
  98                                 ":" kUserAddonsDirectory
  99                                         // TODO: Remove!
 100                                 ":" kSystemNonpackagedAddonsDirectory
 101                                 ":" kSystemAddonsDirectory;
 102
 103                 default:
 104                         return NULL;
 105         }
 106 }
 107
 108
 109 static bool
 110 replace_executable_path_placeholder(const char*& dir, int& dirLength,
 111         const char* placeholder, size_t placeholderLength,
 112         const char* replacementSubPath, char*& buffer, size_t& bufferSize,
 113         status_t& _error)
 114 {
 115         if (dirLength < (int)placeholderLength
 116                 || strncmp(dir, placeholder, placeholderLength) != 0) {
 117                 return false;
 118         }
 119
 120         if (replacementSubPath == NULL) {
 121                 _error = B_ENTRY_NOT_FOUND;
 122                 return true;
 123         }
 124
 125         char* lastSlash = strrchr(replacementSubPath, '/');
 126
 127         // Copy replacementSubPath without the last component (the application file
 128         // name, respectively the requesting executable file name).
 129         size_t toCopy;
 130         if (lastSlash != NULL) {
 131                 toCopy = lastSlash - replacementSubPath;
 132                 strlcpy(buffer, replacementSubPath,
 133                         std::min((ssize_t)bufferSize, lastSlash + 1 - replacementSubPath));
 134         } else {
 135                 replacementSubPath = ".";
 136                 toCopy = 1;
 137                 strlcpy(buffer, ".", bufferSize);
 138         }
 139
 140         if (toCopy >= bufferSize) {
 141                 _error = B_NAME_TOO_LONG;
 142                 return true;
 143         }
 144
 145         memcpy(buffer, replacementSubPath, toCopy);
 146         buffer[toCopy] = '\0';
 147
 148         buffer += toCopy;
 149         bufferSize -= toCopy;
 150         dir += placeholderLength;
 151         dirLength -= placeholderLength;
 152
 153         _error = B_OK;
 154         return true;
 155 }
 156
 157
 158 static int
 159 try_open_executable(const char *dir, int dirLength, const char *name,
 160         const char *programPath, const char *requestingObjectPath,
 161         const char *abiSpecificSubDir, char *path, size_t pathLength)
 162 {
 163         size_t nameLength = strlen(name);
 164         struct stat stat;
 165         status_t status;
 166
 167         // construct the path
 168         if (dirLength > 0) {
 169                 char *buffer = path;
 170                 size_t subDirLen = 0;
 171
 172                 if (programPath == NULL)
 173                         programPath = gProgramArgs->program_path;
 174
 175                 if (replace_executable_path_placeholder(dir, dirLength, "%A", 2,
 176                                 programPath, buffer, pathLength, status)
 177                         || replace_executable_path_placeholder(dir, dirLength, "$ORIGIN", 7,
 178                                 requestingObjectPath, buffer, pathLength, status)) {
 179                         if (status != B_OK)
 180                                 return status;
 181                 } else if (abiSpecificSubDir != NULL) {
 182                         // We're looking for a library or an add-on and the executable has
 183                         // not been compiled with a compiler using the same ABI as the one
 184                         // the OS has been built with. Thus we only look in subdirs
 185                         // specific to that ABI.
 186                         // However, only if it's a known library location
 187                         for (int i = 0; i < 4; ++i) {
 188                                 char buffer[PATH_MAX];
 189                                 status_t result = __find_directory(kLibraryDirectories[i], -1,
 190                                         false, buffer, PATH_MAX);
 191                                 if (result == B_OK && strncmp(dir, buffer, dirLength) == 0) {
 192                                         subDirLen = strlen(abiSpecificSubDir) + 1;
 193                                         break;
 194                                 }
 195                         }
 196                 }
 197
 198                 if (dirLength + 1 + subDirLen + nameLength >= pathLength)
 199                         return B_NAME_TOO_LONG;
 200
 201                 memcpy(buffer, dir, dirLength);
 202                 buffer[dirLength] = '/';
 203                 if (subDirLen > 0) {
 204                         memcpy(buffer + dirLength + 1, abiSpecificSubDir, subDirLen - 1);
 205                         buffer[dirLength + subDirLen] = '/';
 206                 }
 207                 strcpy(buffer + dirLength + 1 + subDirLen, name);
 208         } else {
 209                 if (nameLength >= pathLength)
 210                         return B_NAME_TOO_LONG;
 211
 212                 strcpy(path + dirLength + 1, name);
 213         }
 214
 215         TRACE(("runtime_loader: try_open_container(): %s\n", path));
 216
 217         // Test if the target is a symbolic link, and correct the path in this case
 218
 219         status = _kern_read_stat(-1, path, false, &stat, sizeof(struct stat));
 220         if (status < B_OK)
 221                 return status;
 222
 223         if (S_ISLNK(stat.st_mode)) {
 224                 char buffer[PATH_MAX];
 225                 size_t length = PATH_MAX - 1;
 226                 char *lastSlash;
 227
 228                 // it's a link, indeed
 229                 status = _kern_read_link(-1, path, buffer, &length);
 230                 if (status < B_OK)
 231                         return status;
 232                 buffer[length] = '\0';
 233
 234                 lastSlash = strrchr(path, '/');
 235                 if (buffer[0] != '/' && lastSlash != NULL) {
 236                         // relative path
 237                         strlcpy(lastSlash + 1, buffer, lastSlash + 1 - path + pathLength);
 238                 } else
 239                         strlcpy(path, buffer, pathLength);
 240         }
 241
 242         return _kern_open(-1, path, O_RDONLY, 0);
 243 }
 244
 245
 246 static int
 247 search_executable_in_path_list(const char *name, const char *pathList,
 248         int pathListLen, const char *programPath, const char *requestingObjectPath,
 249         const char *abiSpecificSubDir, char *pathBuffer, size_t pathBufferLength)
 250 {
 251         const char *pathListEnd = pathList + pathListLen;
 252         status_t status = B_ENTRY_NOT_FOUND;
 253
 254         TRACE(("runtime_loader: search_container_in_path_list() %s in %.*s\n", name,
 255                 pathListLen, pathList));
 256
 257         while (pathListLen > 0) {
 258                 const char *pathEnd = pathList;
 259                 int fd;
 260
 261                 // find the next ':' or run till the end of the string
 262                 while (pathEnd < pathListEnd && *pathEnd != ':')
 263                         pathEnd++;
 264
 265                 fd = try_open_executable(pathList, pathEnd - pathList, name,
 266                         programPath, requestingObjectPath, abiSpecificSubDir, pathBuffer,
 267                         pathBufferLength);
 268                 if (fd >= 0) {
 269                         // see if it's a dir
 270                         struct stat stat;
 271                         status = _kern_read_stat(fd, NULL, true, &stat, sizeof(struct stat));
 272                         if (status == B_OK) {
 273                                 if (!S_ISDIR(stat.st_mode))
 274                                         return fd;
 275                                 status = B_IS_A_DIRECTORY;
 276                         }
 277                         _kern_close(fd);
 278                 }
 279
 280                 pathListLen = pathListEnd - pathEnd - 1;
 281                 pathList = pathEnd + 1;
 282         }
 283
 284         return status;
 285 }
 286
 287
 288 int
 289 open_executable(char *name, image_type type, const char *rpath,
 290         const char *programPath, const char *requestingObjectPath,
 291         const char *abiSpecificSubDir)
 292 {
 293         char buffer[PATH_MAX];
 294         int fd = B_ENTRY_NOT_FOUND;
 295
 296         if (strchr(name, '/')) {
 297                 // the name already contains a path, we don't have to search for it
 298                 fd = _kern_open(-1, name, O_RDONLY, 0);
 299                 if (fd >= 0 || type == B_APP_IMAGE)
 300                         return fd;
 301
 302                 // can't search harder an absolute path add-on name!
 303                 if (type == B_ADD_ON_IMAGE && name[0] == '/')
 304                         return fd;
 305
 306                 // Even though ELF specs don't say this, we give shared libraries
 307                 // and relative path based add-ons another chance and look
 308                 // them up in the usual search paths - at
 309                 // least that seems to be what BeOS does, and since it doesn't hurt...
 310                 if (type == B_LIBRARY_IMAGE) {
 311                         // For library (but not add-on), strip any path from name.
 312                         // Relative path of add-on is kept.
 313                         const char* paths = strrchr(name, '/') + 1;
 314                         memmove(name, paths, strlen(paths) + 1);
 315                 }
 316         }
 317
 318         // try rpath (DT_RPATH)
 319         if (rpath != NULL) {
 320                 // It consists of a colon-separated search path list. Optionally a
 321                 // second search path list follows, separated from the first by a
 322                 // semicolon.
 323                 const char *semicolon = strchr(rpath, ';');
 324                 const char *firstList = (semicolon ? rpath : NULL);
 325                 const char *secondList = (semicolon ? semicolon + 1 : rpath);
 326                         // If there is no ';', we set only secondList to simplify things.
 327                 if (firstList) {
 328                         fd = search_executable_in_path_list(name, firstList,
 329                                 semicolon - firstList, programPath, requestingObjectPath, NULL,
 330                                 buffer, sizeof(buffer));
 331                 }
 332                 if (fd < 0) {
 333                         fd = search_executable_in_path_list(name, secondList,
 334                                 strlen(secondList), programPath, requestingObjectPath, NULL,
 335                                 buffer, sizeof(buffer));
 336                 }
 337         }
 338
 339         // If not found yet, let's evaluate the system path variables to find the
 340         // shared object.
 341         if (fd < 0) {
 342                 if (const char *paths = search_path_for_type(type)) {
 343                         fd = search_executable_in_path_list(name, paths, strlen(paths),
 344                                 programPath, NULL, abiSpecificSubDir, buffer, sizeof(buffer));
 345                 }
 346         }
 347
 348         if (fd >= 0) {
 349                 // we found it, copy path!
 350                 TRACE(("runtime_loader: open_executable(%s): found at %s\n", name, buffer));
 351                 strlcpy(name, buffer, PATH_MAX);
 352         }
 353
 354         return fd;
 355 }
 356
 357
 358 /*!
 359         Applies haiku-specific fixes to a shebang line.
 360 */
 361 static void
 362 fixup_shebang(char *invoker)
 363 {
 364         char *current = invoker;
 365         while (*current == ' ' || *current == '\t') {
 366                 ++current;
 367         }
 368
 369         char *commandStart = current;
 370         while (*current != ' ' && *current != '\t' && *current != '\0') {
 371                 ++current;
 372         }
 373
 374         // replace /usr/bin/env with /bin/env
 375         if (memcmp(commandStart, "/usr/bin/env", current - commandStart) == 0)
 376                 memmove(commandStart, commandStart + 4, strlen(commandStart + 4) + 1);
 377 }
 378
 379
 380 /*!
 381         Tests if there is an executable file at the provided path. It will
 382         also test if the file has a valid ELF header or is a shell script.
 383         Even if the runtime loader does not need to be able to deal with
 384         both types, the caller will give scripts a proper treatment.
 385 */
 386 status_t
 387 test_executable(const char *name, char *invoker)
 388 {
 389         char path[B_PATH_NAME_LENGTH];
 390         char buffer[B_FILE_NAME_LENGTH];
 391                 // must be large enough to hold the ELF header
 392         status_t status;
 393         ssize_t length;
 394         int fd;
 395
 396         if (name == NULL)
 397                 return B_BAD_VALUE;
 398
 399         strlcpy(path, name, sizeof(path));
 400
 401         fd = open_executable(path, B_APP_IMAGE, NULL, NULL, NULL, NULL);
 402         if (fd < B_OK)
 403                 return fd;
 404
 405         // see if it's executable at all
 406         status = _kern_access(-1, path, X_OK, false);
 407         if (status != B_OK)
 408                 goto out;
 409
 410         // read and verify the ELF header
 411
 412         length = _kern_read(fd, 0, buffer, sizeof(buffer));
 413         if (length < 0) {
 414                 status = length;
 415                 goto out;
 416         }
 417
 418         status = elf_verify_header(buffer, length);
 419         if (status == B_NOT_AN_EXECUTABLE) {
 420                 if (!strncmp(buffer, "#!", 2)) {
 421                         // test for shell scripts
 422                         char *end;
 423                         buffer[min_c((size_t)length, sizeof(buffer) - 1)] = '\0';
 424
 425                         end = strchr(buffer, '\n');
 426                         if (end == NULL) {
 427                                 status = E2BIG;
 428                                 goto out;
 429                         } else
 430                                 end[0] = '\0';
 431
 432                         if (invoker) {
 433                                 strcpy(invoker, buffer + 2);
 434                                 fixup_shebang(invoker);
 435                         }
 436
 437                         status = B_OK;
 438                 } else {
 439                         // Something odd like a PE?
 440                         status = pe_verify_header(buffer, length);
 441
 442                         // It is a PE, throw B_UNKNOWN_EXECUTABLE
 443                         // likely win32 at this point
 444                         if (status == B_OK)
 445                                 status = B_UNKNOWN_EXECUTABLE;
 446                 }
 447         } else if (status == B_OK) {
 448                 elf_ehdr *elfHeader = (elf_ehdr *)buffer;
 449                 if (elfHeader->e_entry == 0) {
 450                         // we don't like to open shared libraries
 451                         status = B_NOT_AN_EXECUTABLE;
 452                 } else if (invoker)
 453                         invoker[0] = '\0';
 454         }
 455
 456 out:
 457         _kern_close(fd);
 458         return status;
 459 }
 460
 461
 462 static bool
 463 determine_x86_abi(int fd, const Elf32_Ehdr& elfHeader, bool& _isGcc2)
 464 {
 465         // Unless we're a little-endian CPU, don't bother. We're not x86, so it
 466         // doesn't matter all that much whether we can determine the correct gcc
 467         // ABI. This saves the code below from having to deal with endianess
 468         // conversion.
 469 #if B_HOST_IS_LENDIAN
 470
 471         // Since we don't want to load the complete image, we can't use the
 472         // functions that normally determine the Haiku version and ABI. Instead
 473         // we'll load the symbol and string tables and resolve the ABI symbol
 474         // manually.
 475
 476         // map the file into memory
 477         struct stat st;
 478         if (_kern_read_stat(fd, NULL, true, &st, sizeof(st)) != B_OK)
 479                 return false;
 480
 481         void* fileBaseAddress;
 482         area_id area = _kern_map_file("mapped file", &fileBaseAddress,
 483                 B_ANY_ADDRESS, st.st_size, B_READ_AREA, REGION_NO_PRIVATE_MAP, false,
 484                 fd, 0);
 485         if (area < 0)
 486                 return false;
 487
 488         struct AreaDeleter {
 489                 AreaDeleter(area_id area)
 490                         :
 491                         fArea(area)
 492                 {
 493                 }
 494
 495                 ~AreaDeleter()
 496                 {
 497                         _kern_delete_area(fArea);
 498                 }
 499
 500         private:
 501                 area_id fArea;
 502         } areaDeleter(area);
 503
 504         // get the section headers
 505         if (elfHeader.e_shoff == 0 || elfHeader.e_shentsize < sizeof(Elf32_Shdr))
 506                 return false;
 507
 508         size_t sectionHeadersSize = elfHeader.e_shentsize * elfHeader.e_shnum;
 509         if (elfHeader.e_shoff + (off_t)sectionHeadersSize > st.st_size)
 510                 return false;
 511
 512         void* sectionHeaders = (uint8*)fileBaseAddress + elfHeader.e_shoff;
 513
 514         // find the sections we need
 515         uint32* symbolHash = NULL;
 516         uint32 symbolHashSize = 0;
 517         uint32 symbolHashChainSize = 0;
 518         Elf32_Sym* symbolTable = NULL;
 519         uint32 symbolTableSize = 0;
 520         const char* stringTable = NULL;
 521         off_t stringTableSize = 0;
 522
 523         for (int32 i = 0; i < elfHeader.e_shnum; i++) {
 524                 Elf32_Shdr* sectionHeader
 525                         = (Elf32_Shdr*)((uint8*)sectionHeaders + i * elfHeader.e_shentsize);
 526                 if ((off_t)sectionHeader->sh_offset + (off_t)sectionHeader->sh_size
 527                                 > st.st_size) {
 528                         continue;
 529                 }
 530
 531                 void* sectionAddress = (uint8*)fileBaseAddress
 532                         + sectionHeader->sh_offset;
 533
 534                 switch (sectionHeader->sh_type) {
 535                         case SHT_HASH:
 536                                 symbolHash = (uint32*)sectionAddress;
 537                                 if (sectionHeader->sh_size < (off_t)sizeof(symbolHash[0]))
 538                                         return false;
 539                                 symbolHashSize = symbolHash[0];
 540                                 symbolHashChainSize
 541                                         = sectionHeader->sh_size / sizeof(symbolHash[0]);
 542                                 if (symbolHashChainSize < symbolHashSize + 2)
 543                                         return false;
 544                                 symbolHashChainSize -= symbolHashSize + 2;
 545                                 break;
 546                         case SHT_DYNSYM:
 547                                 symbolTable = (Elf32_Sym*)sectionAddress;
 548                                 symbolTableSize = sectionHeader->sh_size;
 549                                 break;
 550                         case SHT_STRTAB:
 551                                 // .shstrtab has the same type as .dynstr, but it isn't loaded
 552                                 // into memory.
 553                                 if (sectionHeader->sh_addr == 0)
 554                                         continue;
 555                                 stringTable = (const char*)sectionAddress;
 556                                 stringTableSize = (off_t)sectionHeader->sh_size;
 557                                 break;
 558                         default:
 559                                 continue;
 560                 }
 561         }
 562
 563         if (symbolHash == NULL || symbolTable == NULL || stringTable == NULL)
 564                 return false;
 565         uint32 symbolCount
 566                 = std::min(symbolTableSize / (uint32)sizeof(Elf32_Sym),
 567                         symbolHashChainSize);
 568         if (symbolCount < symbolHashSize)
 569                 return false;
 570
 571         // look up the ABI symbol
 572         const char* name = B_SHARED_OBJECT_HAIKU_ABI_VARIABLE_NAME;
 573         size_t nameLength = strlen(name);
 574         uint32 bucket = elf_hash(name) % symbolHashSize;
 575
 576         for (uint32 i = symbolHash[bucket + 2]; i < symbolCount && i != STN_UNDEF;
 577                 i = symbolHash[2 + symbolHashSize + i]) {
 578                 Elf32_Sym* symbol = symbolTable + i;
 579                 if (symbol->st_shndx != SHN_UNDEF
 580                         && ((symbol->Bind() == STB_GLOBAL) || (symbol->Bind() == STB_WEAK))
 581                         && symbol->Type() == STT_OBJECT
 582                         && (off_t)symbol->st_name + (off_t)nameLength < stringTableSize
 583                         && strcmp(stringTable + symbol->st_name, name) == 0) {
 584                         if (symbol->st_value > 0 && symbol->st_size >= sizeof(uint32)
 585                                 && symbol->st_shndx < elfHeader.e_shnum) {
 586                                 Elf32_Shdr* sectionHeader = (Elf32_Shdr*)((uint8*)sectionHeaders
 587                                         + symbol->st_shndx * elfHeader.e_shentsize);
 588                                 if (symbol->st_value >= sectionHeader->sh_addr
 589                                         && symbol->st_value
 590                                                 <= sectionHeader->sh_addr + sectionHeader->sh_size) {
 591                                         off_t fileOffset = symbol->st_value - sectionHeader->sh_addr
 592                                                 + sectionHeader->sh_offset;
 593                                         if (fileOffset + (off_t)sizeof(uint32) <= st.st_size) {
 594                                                 uint32 abi
 595                                                         = *(uint32*)((uint8*)fileBaseAddress + fileOffset);
 596                                                 _isGcc2 = (abi & B_HAIKU_ABI_MAJOR)
 597                                                         == B_HAIKU_ABI_GCC_2;
 598                                                 return true;
 599                                         }
 600                                 }
 601                         }
 602
 603                         return false;
 604                 }
 605         }
 606
 607         // ABI symbol not found. That means the object pre-dates its introduction
 608         // in Haiku. So this is most likely gcc 2. We don't fall back to reading
 609         // the comment sections to verify.
 610         _isGcc2 = true;
 611         return true;
 612 #else   // not little endian
 613         return false;
 614 #endif
 615 }
 616
 617
 618 static status_t
 619 get_executable_architecture(int fd, const char** _architecture)
 620 {
 621         // Read the ELF header. We read the 32 bit header. Generally the e_machine
 622         // field is the last one that interests us and the 64 bit header is still
 623         // identical at that point.
 624         Elf32_Ehdr elfHeader;
 625         ssize_t bytesRead = _kern_read(fd, 0, &elfHeader, sizeof(elfHeader));
 626         if (bytesRead < 0)
 627                 return bytesRead;
 628         if ((size_t)bytesRead != sizeof(elfHeader))
 629                 return B_NOT_AN_EXECUTABLE;
 630
 631         // check whether this is indeed an ELF file
 632         if (memcmp(elfHeader.e_ident, ELF_MAGIC, 4) != 0)
 633                 return B_NOT_AN_EXECUTABLE;
 634
 635         // check the architecture
 636         uint16 machine = elfHeader.e_machine;
 637         if ((elfHeader.e_ident[EI_DATA] == ELFDATA2LSB) != (B_HOST_IS_LENDIAN != 0))
 638                 machine = (machine >> 8) | (machine << 8);
 639
 640         const char* architecture = NULL;
 641         switch (machine) {
 642                 case EM_386:
 643                 case EM_486:
 644                 {
 645                         bool isGcc2;
 646                         if (determine_x86_abi(fd, elfHeader, isGcc2) && isGcc2)
 647                                 architecture = "x86_gcc2";
 648                         else
 649                                 architecture = "x86";
 650                         break;
 651                 }
 652                 case EM_68K:
 653                         architecture = "m68k";
 654                         break;
 655                 case EM_PPC:
 656                         architecture = "ppc";
 657                         break;
 658                 case EM_ARM:
 659                         architecture = "arm";
 660                         break;
 661                 case EM_X86_64:
 662                         architecture = "x86_64";
 663                         break;
 664         }
 665
 666         if (architecture == NULL)
 667                 return B_NOT_SUPPORTED;
 668
 669         *_architecture = architecture;
 670         return B_OK;
 671 }
 672
 673
 674 status_t
 675 get_executable_architecture(const char* path, const char** _architecture)
 676 {
 677         int fd = _kern_open(-1, path, O_RDONLY, 0);
 678         if (fd < 0)
 679                 return fd;
 680
 681         status_t error = get_executable_architecture(fd, _architecture);
 682
 683         _kern_close(fd);
 684         return error;
 685 }
 686
 687
 688 /*!
 689         This is the main entry point of the runtime loader as
 690         specified by its ld-script.
 691 */
 692 int
 693 runtime_loader(void* _args, void* commpage)
 694 {
 695         void *entry = NULL;
 696         int returnCode;
 697
 698         gProgramArgs = (struct user_space_program_args *)_args;
 699         __gCommPageAddress = commpage;
 700
 701         // Relocate the args and env arrays -- they are organized in a contiguous
 702         // buffer which the kernel just copied into user space without adjusting the
 703         // pointers.
 704         {
 705                 int32 i;
 706                 addr_t relocationOffset = 0;
 707
 708                 if (gProgramArgs->arg_count > 0)
 709                         relocationOffset = (addr_t)gProgramArgs->args[0];
 710                 else if (gProgramArgs->env_count > 0)
 711                         relocationOffset = (addr_t)gProgramArgs->env[0];
 712
 713                 // That's basically: <new buffer address> - <old buffer address>.
 714                 // It looks a little complicated, since we don't have the latter one at
 715                 // hand and thus need to reconstruct it (<first string pointer> -
 716                 // <arguments + environment array sizes>).
 717                 relocationOffset = (addr_t)gProgramArgs->args - relocationOffset
 718                         + (gProgramArgs->arg_count + gProgramArgs->env_count + 2)
 719                                 * sizeof(char*);
 720
 721                 for (i = 0; i < gProgramArgs->arg_count; i++)
 722                         gProgramArgs->args[i] += relocationOffset;
 723
 724                 for (i = 0; i < gProgramArgs->env_count; i++)
 725                         gProgramArgs->env[i] += relocationOffset;
 726         }
 727
 728 #if DEBUG_RLD
 729         close(0); open("/dev/console", 0); /* stdin   */
 730         close(1); open("/dev/console", 0); /* stdout  */
 731         close(2); open("/dev/console", 0); /* stderr  */
 732 #endif
 733
 734         if (heap_init() < B_OK)
 735                 return 1;
 736
 737         rldexport_init();
 738         rldelf_init();
 739
 740         load_program(gProgramArgs->program_path, &entry);
 741
 742         if (entry == NULL)
 743                 return -1;
 744
 745         // call the program entry point (usually _start())
 746         returnCode = ((int (*)(int, void *, void *))entry)(gProgramArgs->arg_count,
 747                 gProgramArgs->args, gProgramArgs->env);
 748
 749         terminate_program();
 750
 751         return returnCode;
 752 }