Usermode/Libraries/ld-acess.so_src/elf.c

   1 /*
   2  * AcessOS 1 - Dynamic Loader
   3  * By thePowersGang
   4  */
   5 #include "common.h"
   6 #include <stdint.h>
   7 #include "elf32.h"
   8 #include "elf64.h"
   9
  10 #define DEBUG   1
  11
  12 #if DEBUG
  13 # define        DEBUGS(v...)    SysDebug("ld-acess - " v)
  14 #else
  15 # define        DEBUGS(...)
  16 #endif
  17
  18 #if BITS > 32
  19 # define SUPPORT_ELF64
  20 #endif
  21
  22 // === CONSTANTS ===
  23 #if DEBUG
  24 //static const char     *csaDT_NAMES[] = {"DT_NULL", "DT_NEEDED", "DT_PLTRELSZ", "DT_PLTGOT", "DT_HASH", "DT_STRTAB", "DT_SYMTAB", "DT_RELA", "DT_RELASZ", "DT_RELAENT", "DT_STRSZ", "DT_SYMENT", "DT_INIT", "DT_FINI", "DT_SONAME", "DT_RPATH", "DT_SYMBOLIC", "DT_REL", "DT_RELSZ", "DT_RELENT", "DT_PLTREL", "DT_DEBUG", "DT_TEXTREL", "DT_JMPREL"};
  25 static const char       *csaR_NAMES[] = {"R_386_NONE", "R_386_32", "R_386_PC32", "R_386_GOT32", "R_386_PLT32", "R_386_COPY", "R_386_GLOB_DAT", "R_386_JMP_SLOT", "R_386_RELATIVE", "R_386_GOTOFF", "R_386_GOTPC", "R_386_LAST"};
  26 #endif
  27
  28 // === PROTOTYPES ===
  29 void    *ElfRelocate(void *Base, char **envp, const char *Filename);
  30  int    ElfGetSymbol(void *Base, const char *Name, void **Ret);
  31 void    *Elf32Relocate(void *Base, char **envp, const char *Filename);
  32  int    Elf32GetSymbol(void *Base, const char *Name, void **Ret);
  33 #ifdef SUPPORT_ELF64
  34 void    *Elf64Relocate(void *Base, char **envp, const char *Filename);
  35  int    Elf64GetSymbol(void *Base, const char *Name, void **Ret);
  36 #endif
  37 Uint32  ElfHashString(const char *name);
  38
  39 // === CODE ===
  40 /**
  41  * \fn int ElfRelocate(void *Base, char **envp, const char *Filename)
  42  * \brief Relocates a loaded ELF Executable
  43  */
  44 void *ElfRelocate(void *Base, char **envp, const char *Filename)
  45 {
  46         Elf32_Ehdr      *hdr = Base;
  47
  48         switch(hdr->e_ident[4])
  49         {
  50         case ELFCLASS32:
  51                 return Elf32Relocate(Base, envp, Filename);
  52 #ifdef SUPPORT_ELF64
  53         case ELFCLASS64:
  54                 return Elf64Relocate(Base, envp, Filename);
  55 #endif
  56         default:
  57                 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
  58                 return NULL;
  59         }
  60 }
  61
  62 /**
  63  * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
  64  */
  65 int ElfGetSymbol(void *Base, const char *Name, void **ret)
  66 {
  67         Elf32_Ehdr      *hdr = Base;
  68
  69         switch(hdr->e_ident[4])
  70         {
  71         case ELFCLASS32:
  72                 return Elf32GetSymbol(Base, Name, ret);
  73 #ifdef SUPPORT_ELF64
  74         case ELFCLASS64:
  75                 return Elf64GetSymbol(Base, Name, ret);
  76 #endif
  77         default:
  78                 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
  79                 return 0;
  80         }
  81 }
  82
  83 void *Elf32Relocate(void *Base, char **envp, const char *Filename)
  84 {
  85         Elf32_Ehdr      *hdr = Base;
  86         Elf32_Phdr      *phtab;
  87          int    i, j;   // Counters
  88         char    *libPath;
  89         intptr_t        iRealBase = -1;
  90         intptr_t        iBaseDiff;
  91          int    iSegmentCount;
  92          int    iSymCount;
  93         Elf32_Rel       *rel = NULL;
  94         Elf32_Rela      *rela = NULL;
  95         Uint32  *pltgot = NULL;
  96         void    *plt = NULL;
  97          int    relSz=0, relEntSz=8;
  98          int    relaSz=0, relaEntSz=8;
  99          int    pltSz=0, pltType=0;
 100         Elf32_Dyn       *dynamicTab = NULL;     // Dynamic Table Pointer
 101         char    *dynstrtab = NULL;      // .dynamic String Table
 102         Elf32_Sym       *dynsymtab;
 103         void    (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, const char *Sym);
 104
 105         DEBUGS("ElfRelocate: (Base=0x%x)", Base);
 106
 107         // Check magic header
 108
 109
 110         // Parse Program Header to get Dynamic Table
 111         phtab = Base + hdr->phoff;
 112         iSegmentCount = hdr->phentcount;
 113         for(i=0;i<iSegmentCount;i++)
 114         {
 115                 // Determine linked base address
 116                 if(phtab[i].Type == PT_LOAD && iRealBase > phtab[i].VAddr)
 117                         iRealBase = phtab[i].VAddr;
 118
 119                 // Find Dynamic Section
 120                 if(phtab[i].Type == PT_DYNAMIC) {
 121                         if(dynamicTab) {
 122                                 DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
 123                                 continue;
 124                         }
 125                         dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
 126                         j = i;  // Save Dynamic Table ID
 127                 }
 128         }
 129
 130         // Page Align real base
 131         iRealBase &= ~0xFFF;
 132         DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
 133
 134         // Adjust "Real" Base
 135         iBaseDiff = (intptr_t)Base - iRealBase;
 136
 137 //      hdr->entrypoint += iBaseDiff;   // Adjust Entrypoint
 138
 139         // Check if a PT_DYNAMIC segement was found
 140         if(!dynamicTab) {
 141                 SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 142                 return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
 143         }
 144
 145         // Adjust Dynamic Table
 146         dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
 147
 148         // === Get Symbol table and String Table ===
 149         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 150         {
 151                 switch(dynamicTab[j].d_tag)
 152                 {
 153                 // --- Symbol Table ---
 154                 case DT_SYMTAB:
 155                         DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
 156                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 157                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 158                         dynsymtab = (void*)(dynamicTab[j].d_val);
 159 //                      hdr->misc.SymTable = dynamicTab[j].d_val;       // Saved in unused bytes of ident
 160                         break;
 161                 // --- String Table ---
 162                 case DT_STRTAB:
 163                         DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
 164                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 165                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 166                         dynstrtab = (void*)(dynamicTab[j].d_val);
 167                         break;
 168                 // --- Hash Table --
 169                 case DT_HASH:
 170                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 171                         iSymCount = ((Elf32_Word*)(dynamicTab[j].d_val))[1];
 172 //                      hdr->misc.HashTable = dynamicTab[j].d_val;      // Saved in unused bytes of ident
 173                         break;
 174                 }
 175         }
 176
 177         if(dynsymtab == NULL) {
 178                 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
 179                 return (void *) hdr->entrypoint + iBaseDiff;
 180         }
 181
 182         #if 0
 183         // Alter Symbols to true base
 184         for(i=0;i<iSymCount;i++)
 185         {
 186                 dynsymtab[i].value += iBaseDiff;
 187                 dynsymtab[i].nameOfs += (intptr_t)dynstrtab;
 188                 //DEBUGS("elf_relocate: Sym '%s' = 0x%x (relocated)", dynsymtab[i].name, dynsymtab[i].value);
 189         }
 190         #endif
 191
 192         // === Add to loaded list (can be imported now) ===
 193         AddLoaded( Filename, Base );
 194
 195         // === Parse Relocation Data ===
 196         DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
 197         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 198         {
 199                 switch(dynamicTab[j].d_tag)
 200                 {
 201                 // --- Shared Library Name ---
 202                 case DT_SONAME:
 203                         DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
 204                         break;
 205                 // --- Needed Library ---
 206                 case DT_NEEDED:
 207                         libPath = dynstrtab + dynamicTab[j].d_val;
 208                         DEBUGS(" Required Library '%s'", libPath);
 209                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 210                                 #if DEBUG
 211                                 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
 212                                 #else
 213                                 SysDebug("Unable to load required library '%s'", libPath);
 214                                 #endif
 215                                 return 0;
 216                         }
 217                         break;
 218                 // --- PLT/GOT ---
 219                 case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val);      break;
 220                 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 221                 case DT_PLTREL: pltType = dynamicTab[j].d_val;  break;
 222                 case DT_PLTRELSZ:       pltSz = dynamicTab[j].d_val;    break;
 223
 224                 // --- Relocation ---
 225                 case DT_REL:    rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 226                 case DT_RELSZ:  relSz = dynamicTab[j].d_val;    break;
 227                 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
 228                 case DT_RELA:   rela = (void*)(iBaseDiff + dynamicTab[j].d_val);        break;
 229                 case DT_RELASZ: relaSz = dynamicTab[j].d_val;   break;
 230                 case DT_RELAENT:        relaEntSz = dynamicTab[j].d_val;        break;
 231
 232                 // --- Symbol Table ---
 233                 case DT_SYMTAB:
 234                 // --- Hash Table ---
 235                 case DT_HASH:
 236                 // --- String Table ---
 237                 case DT_STRTAB:
 238                         break;
 239
 240                 // --- Unknown ---
 241                 default:
 242                         if(dynamicTab[j].d_tag > DT_JMPREL)     continue;
 243                         //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
 244                         //      i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
 245                         break;
 246                 }
 247         }
 248
 249         DEBUGS(" elf_relocate: Beginning Relocation");
 250
 251         void elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, const char *Sym)
 252         {
 253                 Uint32  val;
 254                 switch( type )
 255                 {
 256                 // Standard 32 Bit Relocation (S+A)
 257                 case R_386_32:
 258                         val = (intptr_t) GetSymbol( Sym );
 259                         DEBUGS(" elf_doRelocate: R_386_32 *0x%x += 0x%x('%s')",
 260                                         ptr, val, Sym);
 261                         *ptr = val + addend;
 262                         break;
 263
 264                 // 32 Bit Relocation wrt. Offset (S+A-P)
 265                 case R_386_PC32:
 266                         DEBUGS(" elf_doRelocate: '%s'", Sym);
 267                         val = (intptr_t) GetSymbol( Sym );
 268                         DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%x - 0x%x",
 269                                 ptr, *ptr, val, (intptr_t)ptr );
 270                         *ptr = val + addend - (intptr_t)ptr;
 271                         //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
 272                         break;
 273
 274                 // Absolute Value of a symbol (S)
 275                 case R_386_GLOB_DAT:
 276                 case R_386_JMP_SLOT:
 277                         DEBUGS(" elf_doRelocate: '%s'", Sym);
 278                         val = (intptr_t) GetSymbol( Sym );
 279                         DEBUGS(" elf_doRelocate: %s *0x%x = 0x%x", csaR_NAMES[type], ptr, val);
 280                         *ptr = val;
 281                         break;
 282
 283                 // Base Address (B+A)
 284                 case R_386_RELATIVE:
 285                         DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
 286                         *ptr = iBaseDiff + addend;
 287                         break;
 288
 289                 default:
 290                         SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
 291                         break;
 292                 }
 293         }
 294
 295         void elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, const char *Sym)
 296         {
 297                 uint32_t        val;
 298                 switch(type)
 299                 {
 300                 // (S + A) | T
 301                 case R_ARM_GLOB_DAT:
 302                 case R_ARM_JUMP_SLOT:
 303                         val = (intptr_t)GetSymbol(Sym);
 304                         *ptr = val + addend;
 305                         break;
 306                 default:
 307                         SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
 308                         break;
 309                 }
 310         }
 311
 312         void _doRelocate(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend)
 313         {
 314                  int    type = ELF32_R_TYPE(r_info);
 315                  int    sym = ELF32_R_SYM(r_info);
 316                 const char      *symname = dynstrtab + dynsymtab[sym].nameOfs;
 317                 do_relocate(r_info, ptr, addend, type, symname);
 318         }
 319
 320         switch(hdr->machine)
 321         {
 322         case EM_386:
 323                 do_relocate = elf_doRelocate_386;
 324                 break;
 325         case EM_ARM:
 326                 do_relocate = elf_doRelocate_arm;
 327                 break;
 328         default:
 329                 SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
 330                 break;
 331         }
 332
 333         // Parse Relocation Entries
 334         if(rel && relSz)
 335         {
 336                 Uint32  *ptr;
 337                 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
 338                 j = relSz / relEntSz;
 339                 for( i = 0; i < j; i++ )
 340                 {
 341                         //DEBUGS("  Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
 342                         ptr = (void*)(iBaseDiff + rel[i].r_offset);
 343                         _doRelocate(rel[i].r_info, ptr, *ptr);
 344                 }
 345         }
 346         // Parse Relocation Entries
 347         if(rela && relaSz)
 348         {
 349                 Uint32  *ptr;
 350                 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
 351                 j = relaSz / relaEntSz;
 352                 for( i = 0; i < j; i++ )
 353                 {
 354                         ptr = (void*)(iBaseDiff + rela[i].r_offset);
 355                         _doRelocate(rel[i].r_info, ptr, rela[i].r_addend);
 356                 }
 357         }
 358
 359         // === Process PLT (Procedure Linkage Table) ===
 360         if(plt && pltSz)
 361         {
 362                 Uint32  *ptr;
 363                 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
 364                 if(pltType == DT_REL)
 365                 {
 366                         Elf32_Rel       *pltRel = plt;
 367                         j = pltSz / sizeof(Elf32_Rel);
 368                         DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", j);
 369                         for(i=0;i<j;i++)
 370                         {
 371                                 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
 372                                 _doRelocate(pltRel[i].r_info, ptr, *ptr);
 373                         }
 374                 }
 375                 else
 376                 {
 377                         Elf32_Rela      *pltRela = plt;
 378                         j = pltSz / sizeof(Elf32_Rela);
 379                         DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", j);
 380                         for(i=0;i<j;i++)
 381                         {
 382                                 ptr = (void*)(iRealBase + pltRela[i].r_offset);
 383                                 _doRelocate(pltRela[i].r_info, ptr, pltRela[i].r_addend);
 384                         }
 385                 }
 386         }
 387
 388         DEBUGS("ElfRelocate: RETURN 0x%x", hdr->entrypoint + iBaseDiff);
 389         return (void*)hdr->entrypoint + iBaseDiff;
 390 }
 391
 392 int Elf32GetSymbol(void *Base, const char *Name, void **ret)
 393 {
 394         Elf32_Ehdr      *hdr = Base;
 395         Elf32_Sym       *symtab;
 396          int    nbuckets = 0;
 397          int    iSymCount = 0;
 398          int    i;
 399         Uint32  *pBuckets;
 400         Uint32  *pChains;
 401         uint32_t        iNameHash;
 402         const char      *dynstrtab;
 403         uintptr_t       iBaseDiff = -1;
 404         Elf32_Phdr      *phtab;
 405         Elf32_Dyn       *dynTab = NULL;
 406
 407         // Locate the tables
 408         phtab = (void*)( Base + hdr->phoff );
 409         for( i = 0; i < hdr->phentcount; i ++ )
 410         {
 411                 if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
 412                         iBaseDiff = phtab[i].VAddr;
 413                 if( phtab[i].Type == PT_DYNAMIC ) {
 414                         dynTab = (void*)(intptr_t)phtab[i].VAddr;
 415                 }
 416         }
 417         if( !dynTab ) {
 418                 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 419                 return 0;
 420         }
 421         iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 422         dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 423         for( i = 0; dynTab[i].d_tag != DT_NULL; i++)
 424         {
 425                 switch(dynTab[i].d_tag)
 426                 {
 427                 // --- Symbol Table ---
 428                 case DT_SYMTAB:
 429                         symtab = (void*)(intptr_t) dynTab[i].d_val;     // Rebased in Relocate
 430                         break;
 431                 case DT_STRTAB:
 432                         dynstrtab = (void*)(intptr_t) dynTab[i].d_val;
 433                         break;
 434                 // --- Hash Table --
 435                 case DT_HASH:
 436                         pBuckets = (void*)(intptr_t) dynTab[i].d_val;
 437                         break;
 438                 }
 439         }
 440
 441         nbuckets = pBuckets[0];
 442         iSymCount = pBuckets[1];
 443         pBuckets = &pBuckets[2];
 444         pChains = &pBuckets[ nbuckets ];
 445
 446         // Get hash
 447         iNameHash = ElfHashString(Name);
 448         iNameHash %= nbuckets;
 449
 450         // Walk Chain
 451         i = pBuckets[ iNameHash ];
 452         if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
 453                 *ret = (void*) (intptr_t) symtab[ i ].value + iBaseDiff;
 454                 return 1;
 455         }
 456
 457         while(pChains[i] != STN_UNDEF)
 458         {
 459                 i = pChains[i];
 460                 if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
 461                         *ret = (void*)(intptr_t)symtab[ i ].value + iBaseDiff;
 462                         return 1;
 463                 }
 464         }
 465
 466         return 0;
 467 }
 468
 469 #ifdef SUPPORT_ELF64
 470 void *Elf64Relocate(void *Base, char **envp, const char *Filename)
 471 {
 472          int    i;
 473         Elf64_Ehdr      *hdr = Base;
 474         Elf64_Phdr      *phtab;
 475         Elf64_Dyn       *dyntab;
 476         Elf64_Addr      compiledBase = -1, baseDiff;
 477         Elf64_Sym       *symtab = NULL;
 478         char    *strtab = NULL;
 479         Elf64_Word      *hashtab = NULL;
 480         Elf64_Rel       *rel = NULL;
 481          int    rel_count = 0;
 482         Elf64_Rela      *rela = NULL;
 483          int    rela_count = 0;
 484         void    *pltrel = NULL;
 485          int    plt_size = 0, plt_type = 0;
 486
 487         DEBUGS("Elf64Relocate: hdr = {");
 488         DEBUGS("Elf64Relocate:  e_ident = '%.16s'", hdr->e_ident);
 489         DEBUGS("Elf64Relocate:  e_type = 0x%x", hdr->e_type);
 490         DEBUGS("Elf64Relocate:  e_machine = 0x%x", hdr->e_machine);
 491         DEBUGS("Elf64Relocate:  e_version = 0x%x", hdr->e_version);
 492         DEBUGS("Elf64Relocate:  e_entry = %p", hdr->e_entry);
 493         DEBUGS("Elf64Relocate:  e_phoff = 0x%llx", hdr->e_phoff);
 494         DEBUGS("Elf64Relocate:  e_shoff = 0x%llx", hdr->e_shoff);
 495         DEBUGS("Elf64Relocate:  e_flags = 0x%x", hdr->e_flags);
 496         DEBUGS("Elf64Relocate:  e_ehsize = 0x%x", hdr->e_ehsize);
 497         DEBUGS("Elf64Relocate:  e_phentsize = 0x%x", hdr->e_phentsize);
 498         DEBUGS("Elf64Relocate:  e_phnum = %i", hdr->e_phnum);
 499
 500         // Scan for the dynamic table (and find the compiled base)
 501         phtab = Base + hdr->e_phoff;
 502         for( i = 0; i < hdr->e_phnum; i ++ )
 503         {
 504                 if(phtab[i].p_type == PT_DYNAMIC)
 505                         dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
 506                 if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
 507                         compiledBase = phtab[i].p_vaddr;
 508         }
 509
 510         baseDiff = (Elf64_Addr)Base - compiledBase;
 511
 512         DEBUGS("baseDiff = %p", baseDiff);
 513
 514         if(dyntab == NULL) {
 515                 SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 516                 return (void *)(hdr->e_entry + baseDiff);
 517         }
 518
 519         dyntab = (void *)((Elf64_Addr)dyntab + baseDiff);
 520
 521         // Parse the dynamic table (first pass)
 522         // - Search for String, Symbol and Hash tables
 523         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 524         {
 525                 switch(dyntab[i].d_tag)
 526                 {
 527                 case DT_SYMTAB:
 528                         dyntab[i].d_un.d_ptr += baseDiff;
 529                         symtab = (void *)dyntab[i].d_un.d_ptr;
 530                         break;
 531                 case DT_STRTAB:
 532                         dyntab[i].d_un.d_ptr += baseDiff;
 533                         strtab = (void *)dyntab[i].d_un.d_ptr;
 534                         break;
 535                 case DT_HASH:
 536                         dyntab[i].d_un.d_ptr += baseDiff;
 537                         hashtab = (void *)dyntab[i].d_un.d_ptr;
 538                         break;
 539                 }
 540         }
 541
 542         if( !symtab || !strtab || !hashtab ) {
 543                 SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
 544                 return NULL;
 545         }
 546
 547         // Ready for symbol use
 548         AddLoaded( Filename, Base );
 549
 550         // Second pass on dynamic table
 551         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 552         {
 553                 DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
 554                 switch(dyntab[i].d_tag)
 555                 {
 556                 case DT_SONAME: break;
 557
 558                 case DT_NEEDED: {
 559                         char *libPath = strtab + dyntab[i].d_un.d_val;
 560                         DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
 561                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 562                                 SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
 563                                 return NULL;
 564                         }
 565                         } break;
 566
 567                 // Relocation entries
 568                 case DT_REL:
 569                         dyntab[i].d_un.d_ptr += baseDiff;
 570                         rel = (void *)dyntab[i].d_un.d_ptr;
 571                         break;
 572                 case DT_RELSZ:
 573                         rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
 574                         break;
 575                 case DT_RELENT:
 576                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
 577                                 SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
 578                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
 579                                 return NULL;
 580                         }
 581                         break;
 582                 case DT_RELA:
 583                         dyntab[i].d_un.d_ptr += baseDiff;
 584                         rela = (void *)dyntab[i].d_un.d_ptr;
 585                         break;
 586                 case DT_RELASZ:
 587                         rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
 588                         break;
 589                 case DT_RELAENT:
 590                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
 591                                 SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
 592                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
 593                                 return NULL;
 594                         }
 595                         break;
 596                 case DT_JMPREL:
 597                         dyntab[i].d_un.d_ptr += baseDiff;
 598                         pltrel = (void *)dyntab[i].d_un.d_ptr;
 599                         break;
 600                 case DT_PLTREL:
 601                         plt_type = dyntab[i].d_un.d_val;
 602                         break;
 603                 case DT_PLTRELSZ:
 604                         plt_size = dyntab[i].d_un.d_val;
 605                         break;
 606                 }
 607         }
 608
 609         // Relocation function
 610         void _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
 611         {
 612                  int    sym = ELF64_R_SYM(r_info);
 613                  int    type = ELF64_R_TYPE(r_info);
 614                 const char      *symname = strtab + symtab[sym].st_name;
 615                 switch( type )
 616                 {
 617                 case R_X86_64_NONE:
 618                         break;
 619                 case R_X86_64_64:
 620                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname) + addend;
 621                         break;
 622                 case R_X86_64_COPY:
 623                         break;
 624                 case R_X86_64_GLOB_DAT:
 625                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname);
 626                         break;
 627                 case R_X86_64_JUMP_SLOT:
 628                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname);
 629                         break;
 630                 default:
 631                         SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
 632                         break;
 633                 }
 634         }
 635
 636         if( rel )
 637         {
 638                 DEBUGS("rel_count = %i", rel_count);
 639                 for( i = 0; i < rel_count; i ++ )
 640                 {
 641                         uint64_t *ptr = (void *)( rel[i].r_offset + baseDiff );
 642                         _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
 643                 }
 644         }
 645
 646         if( rela )
 647         {
 648                 DEBUGS("rela_count = %i", rela_count);
 649                 for( i = 0; i < rela_count; i ++ )
 650                 {
 651                         _Elf64DoReloc( rela[i].r_info, (void *)( rela[i].r_offset + baseDiff ), rela[i].r_addend );
 652                 }
 653         }
 654
 655         if( pltrel && plt_type )
 656         {
 657                 if( plt_type == DT_REL ) {
 658                         Elf64_Rel       *plt = pltrel;
 659                          int    count = plt_size / sizeof(Elf64_Rel);
 660                         DEBUGS("plt rel count = %i", count);
 661                         for( i = 0; i < count; i ++ )
 662                         {
 663                                 uint64_t *ptr = (void *)( plt[i].r_offset + baseDiff );
 664                                 _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
 665                         }
 666                 }
 667                 else {
 668                         Elf64_Rela      *plt = pltrel;
 669                          int    count = plt_size / sizeof(Elf64_Rela);
 670                         DEBUGS("plt rela count = %i", count);
 671                         for( i = 0; i < count; i ++ )
 672                         {
 673                                 _Elf64DoReloc( plt[i].r_info, (void *)(plt[i].r_offset + baseDiff), plt[i].r_addend);
 674                         }
 675                 }
 676         }
 677
 678         DEBUGS("Elf64Relocate: Relocations done, return %p", (void *)(hdr->e_entry + baseDiff));
 679         return (void *)(hdr->e_entry + baseDiff);
 680 }
 681
 682 int Elf64GetSymbol(void *Base, const char *Name, void **Ret)
 683 {
 684         Elf64_Ehdr      *hdr = Base;
 685         Elf64_Sym       *symtab;
 686          int    nbuckets = 0;
 687          int    iSymCount = 0;
 688          int    i;
 689         Elf64_Word      *pBuckets;
 690         Elf64_Word      *pChains;
 691         uint32_t        iNameHash;
 692         const char      *dynstrtab;
 693         uintptr_t       iBaseDiff = -1;
 694
 695         dynstrtab = NULL;
 696         pBuckets = NULL;
 697         symtab = NULL;
 698
 699         // Catch the current executable
 700         if( !pBuckets )
 701         {
 702                 Elf64_Phdr      *phtab;
 703                 Elf64_Dyn       *dynTab = NULL;
 704                  int    j;
 705
 706                 // Locate the tables
 707                 phtab = (void*)( Base + hdr->e_phoff );
 708                 for( i = 0; i < hdr->e_phnum; i ++ )
 709                 {
 710                         if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
 711                                 iBaseDiff = phtab[i].p_vaddr;
 712                         if( phtab[i].p_type == PT_DYNAMIC ) {
 713                                 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
 714                         }
 715                 }
 716                 if( !dynTab ) {
 717                         SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 718                         return 0;
 719                 }
 720                 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 721                 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 722
 723                 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
 724                 {
 725                         switch(dynTab[j].d_tag)
 726                         {
 727                         // --- Symbol Table ---
 728                         case DT_SYMTAB:
 729                                 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val;        // Rebased in Relocate
 730                                 break;
 731                         case DT_STRTAB:
 732                                 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
 733                                 break;
 734                         // --- Hash Table --
 735                         case DT_HASH:
 736                                 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
 737                                 break;
 738                         }
 739                 }
 740         }
 741
 742         nbuckets = pBuckets[0];
 743         iSymCount = pBuckets[1];
 744         pBuckets = &pBuckets[2];
 745         pChains = &pBuckets[ nbuckets ];
 746
 747         // Get hash
 748         iNameHash = ElfHashString(Name);
 749         iNameHash %= nbuckets;
 750
 751         // Walk Chain
 752         i = pBuckets[ iNameHash ];
 753         if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 754                 *Ret = (void*) (intptr_t) symtab[i].st_value + iBaseDiff;
 755                 DEBUGS("%s = %p", Name, *Ret);
 756                 return 1;
 757         }
 758
 759         while(pChains[i] != STN_UNDEF)
 760         {
 761                 i = pChains[i];
 762                 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 763                         *Ret = (void*)(intptr_t)symtab[i].st_value + iBaseDiff;
 764                         DEBUGS("%s = %p", Name, *Ret);
 765                         return 1;
 766                 }
 767         }
 768
 769         return 0;
 770 }
 771 #endif
 772
 773
 774 Uint32 ElfHashString(const char *name)
 775 {
 776         Uint32  h = 0, g;
 777         while(*name)
 778         {
 779                 h = (h << 4) + *(Uint8*)name++;
 780                 if( (g = h & 0xf0000000) )
 781                         h ^= g >> 24;
 782                 h &= ~g;
 783         }
 784         return h;
 785 }
 786