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   0
  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, size_t *Size);
  31 void    *Elf32Relocate(void *Base, char **envp, const char *Filename);
  32  int    Elf32GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  33 #ifdef SUPPORT_ELF64
  34 void    *Elf64Relocate(void *Base, char **envp, const char *Filename);
  35  int    Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  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, size_t *Size)
  66 {
  67         Elf32_Ehdr      *hdr = Base;
  68
  69         switch(hdr->e_ident[4])
  70         {
  71         case ELFCLASS32:
  72                 return Elf32GetSymbol(Base, Name, ret, Size);
  73 #ifdef SUPPORT_ELF64
  74         case ELFCLASS64:
  75                 return Elf64GetSymbol(Base, Name, ret, Size);
  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*)(intptr_t)dynamicTab[j].d_val;
 159                         break;
 160                 // --- String Table ---
 161                 case DT_STRTAB:
 162                         DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
 163                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 164                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 165                         dynstrtab = (void*)(intptr_t)dynamicTab[j].d_val;
 166                         break;
 167                 // --- Hash Table --
 168                 case DT_HASH:
 169                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 170                         iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
 171                         break;
 172                 }
 173         }
 174
 175         if(dynsymtab == NULL) {
 176                 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
 177                 return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
 178         }
 179
 180         // === Add to loaded list (can be imported now) ===
 181         AddLoaded( Filename, Base );
 182
 183         // === Parse Relocation Data ===
 184         DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
 185         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 186         {
 187                 switch(dynamicTab[j].d_tag)
 188                 {
 189                 // --- Shared Library Name ---
 190                 case DT_SONAME:
 191                         DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
 192                         break;
 193                 // --- Needed Library ---
 194                 case DT_NEEDED:
 195                         libPath = dynstrtab + dynamicTab[j].d_val;
 196                         DEBUGS(" Required Library '%s'", libPath);
 197                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 198                                 #if DEBUG
 199                                 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
 200                                 #else
 201                                 SysDebug("Unable to load required library '%s'", libPath);
 202                                 #endif
 203                                 return 0;
 204                         }
 205                         DEBUGS(" Lib loaded");
 206                         break;
 207                 // --- PLT/GOT ---
 208                 case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val);      break;
 209                 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 210                 case DT_PLTREL: pltType = dynamicTab[j].d_val;  break;
 211                 case DT_PLTRELSZ:       pltSz = dynamicTab[j].d_val;    break;
 212
 213                 // --- Relocation ---
 214                 case DT_REL:    rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 215                 case DT_RELSZ:  relSz = dynamicTab[j].d_val;    break;
 216                 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
 217                 case DT_RELA:   rela = (void*)(iBaseDiff + dynamicTab[j].d_val);        break;
 218                 case DT_RELASZ: relaSz = dynamicTab[j].d_val;   break;
 219                 case DT_RELAENT:        relaEntSz = dynamicTab[j].d_val;        break;
 220
 221                 // --- Symbol Table ---
 222                 case DT_SYMTAB:
 223                 // --- Hash Table ---
 224                 case DT_HASH:
 225                 // --- String Table ---
 226                 case DT_STRTAB:
 227                         break;
 228
 229                 // --- Unknown ---
 230                 default:
 231                         if(dynamicTab[j].d_tag > DT_JMPREL)     continue;
 232                         //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
 233                         //      i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
 234                         break;
 235                 }
 236         }
 237
 238         DEBUGS(" elf_relocate: Beginning Relocation");
 239
 240         void elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, const char *Sym)
 241         {
 242                 Uint32  val;
 243                 switch( type )
 244                 {
 245                 // Standard 32 Bit Relocation (S+A)
 246                 case R_386_32:
 247                         val = (intptr_t) GetSymbol(Sym, NULL);
 248                         DEBUGS(" elf_doRelocate: R_386_32 *0x%x += 0x%x('%s')",
 249                                         ptr, val, Sym);
 250                         *ptr = val + addend;
 251                         break;
 252
 253                 // 32 Bit Relocation wrt. Offset (S+A-P)
 254                 case R_386_PC32:
 255                         DEBUGS(" elf_doRelocate: '%s'", Sym);
 256                         val = (intptr_t) GetSymbol(Sym, NULL);
 257                         DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%x - 0x%x",
 258                                 ptr, *ptr, val, (intptr_t)ptr );
 259                         *ptr = val + addend - (intptr_t)ptr;
 260                         //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
 261                         break;
 262
 263                 // Absolute Value of a symbol (S)
 264                 case R_386_GLOB_DAT:
 265                 case R_386_JMP_SLOT:
 266                         DEBUGS(" elf_doRelocate: '%s'", Sym);
 267                         val = (intptr_t) GetSymbol( Sym, NULL );
 268                         DEBUGS(" elf_doRelocate: %s *0x%x = 0x%x", csaR_NAMES[type], ptr, val);
 269                         *ptr = val;
 270                         break;
 271
 272                 // Base Address (B+A)
 273                 case R_386_RELATIVE:
 274                         DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
 275                         *ptr = iBaseDiff + addend;
 276                         break;
 277
 278                 case R_386_COPY: {
 279                         size_t  size;
 280                         void    *src = GetSymbol(Sym, &size);
 281                         DEBUGS(" elf_doRelocate_386: R_386_COPY (%p, %p, %i)", ptr, val, size);
 282                         memcpy(ptr, src, size);
 283                         break; }
 284
 285                 default:
 286                         SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
 287                         break;
 288                 }
 289         }
 290
 291         void elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, const char *Sym)
 292         {
 293                 uint32_t        val;
 294                 switch(type)
 295                 {
 296                 // (S + A) | T
 297                 case R_ARM_GLOB_DAT:
 298                 case R_ARM_JUMP_SLOT:
 299                         val = (intptr_t)GetSymbol(Sym, NULL);
 300                         *ptr = val + addend;
 301                         break;
 302                 default:
 303                         SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
 304                         break;
 305                 }
 306         }
 307
 308         void _doRelocate(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend)
 309         {
 310                  int    type = ELF32_R_TYPE(r_info);
 311                  int    sym = ELF32_R_SYM(r_info);
 312                 const char      *symname = dynstrtab + dynsymtab[sym].nameOfs;
 313                 do_relocate(r_info, ptr, addend, type, symname);
 314         }
 315
 316         switch(hdr->machine)
 317         {
 318         case EM_386:
 319                 do_relocate = elf_doRelocate_386;
 320                 break;
 321         case EM_ARM:
 322                 do_relocate = elf_doRelocate_arm;
 323                 break;
 324         default:
 325                 SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
 326                 break;
 327         }
 328
 329         // Parse Relocation Entries
 330         if(rel && relSz)
 331         {
 332                 Uint32  *ptr;
 333                 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
 334                 j = relSz / relEntSz;
 335                 for( i = 0; i < j; i++ )
 336                 {
 337                         //DEBUGS("  Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
 338                         ptr = (void*)(iBaseDiff + rel[i].r_offset);
 339                         _doRelocate(rel[i].r_info, ptr, *ptr);
 340                 }
 341         }
 342         // Parse Relocation Entries
 343         if(rela && relaSz)
 344         {
 345                 Uint32  *ptr;
 346                 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
 347                 j = relaSz / relaEntSz;
 348                 for( i = 0; i < j; i++ )
 349                 {
 350                         ptr = (void*)(iBaseDiff + rela[i].r_offset);
 351                         _doRelocate(rel[i].r_info, ptr, rela[i].r_addend);
 352                 }
 353         }
 354
 355         // === Process PLT (Procedure Linkage Table) ===
 356         if(plt && pltSz)
 357         {
 358                 Uint32  *ptr;
 359                 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
 360                 if(pltType == DT_REL)
 361                 {
 362                         Elf32_Rel       *pltRel = plt;
 363                         j = pltSz / sizeof(Elf32_Rel);
 364                         DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", j);
 365                         for(i=0;i<j;i++)
 366                         {
 367                                 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
 368                                 _doRelocate(pltRel[i].r_info, ptr, *ptr);
 369                         }
 370                 }
 371                 else
 372                 {
 373                         Elf32_Rela      *pltRela = plt;
 374                         j = pltSz / sizeof(Elf32_Rela);
 375                         DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", j);
 376                         for(i=0;i<j;i++)
 377                         {
 378                                 ptr = (void*)(iRealBase + pltRela[i].r_offset);
 379                                 _doRelocate(pltRela[i].r_info, ptr, pltRela[i].r_addend);
 380                         }
 381                 }
 382         }
 383
 384         DEBUGS("ElfRelocate: RETURN 0x%x", hdr->entrypoint + iBaseDiff);
 385         return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff );
 386 }
 387
 388 int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
 389 {
 390         Elf32_Ehdr      *hdr = Base;
 391         Elf32_Sym       *symtab;
 392          int    nbuckets = 0;
 393          int    iSymCount = 0;
 394          int    i;
 395         Uint32  *pBuckets;
 396         Uint32  *pChains;
 397         uint32_t        iNameHash;
 398         const char      *dynstrtab;
 399         uintptr_t       iBaseDiff = -1;
 400         Elf32_Phdr      *phtab;
 401         Elf32_Dyn       *dynTab = NULL;
 402
 403         // Locate the tables
 404         phtab = (void*)( Base + hdr->phoff );
 405         for( i = 0; i < hdr->phentcount; i ++ )
 406         {
 407                 if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
 408                         iBaseDiff = phtab[i].VAddr;
 409                 if( phtab[i].Type == PT_DYNAMIC ) {
 410                         dynTab = (void*)(intptr_t)phtab[i].VAddr;
 411                 }
 412         }
 413         if( !dynTab ) {
 414                 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 415                 return 0;
 416         }
 417         iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 418         dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 419         for( i = 0; dynTab[i].d_tag != DT_NULL; i++)
 420         {
 421                 switch(dynTab[i].d_tag)
 422                 {
 423                 // --- Symbol Table ---
 424                 case DT_SYMTAB:
 425                         symtab = (void*)(intptr_t) dynTab[i].d_val;     // Rebased in Relocate
 426                         break;
 427                 case DT_STRTAB:
 428                         dynstrtab = (void*)(intptr_t) dynTab[i].d_val;
 429                         break;
 430                 // --- Hash Table --
 431                 case DT_HASH:
 432                         pBuckets = (void*)(intptr_t) dynTab[i].d_val;
 433                         break;
 434                 }
 435         }
 436
 437         nbuckets = pBuckets[0];
 438         iSymCount = pBuckets[1];
 439         pBuckets = &pBuckets[2];
 440         pChains = &pBuckets[ nbuckets ];
 441
 442         // Get hash
 443         iNameHash = ElfHashString(Name);
 444         iNameHash %= nbuckets;
 445
 446         // Walk Chain
 447         i = pBuckets[ iNameHash ];
 448         if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
 449                 *ret = (void*) (intptr_t) symtab[ i ].value + iBaseDiff;
 450                 if(Size)        *Size = symtab[i].size;
 451                 return 1;
 452         }
 453
 454         while(pChains[i] != STN_UNDEF)
 455         {
 456                 i = pChains[i];
 457                 if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
 458                         *ret = (void*)(intptr_t)symtab[ i ].value + iBaseDiff;
 459                         if(Size)        *Size = symtab[i].size;
 460                         return 1;
 461                 }
 462         }
 463
 464         return 0;
 465 }
 466
 467 #ifdef SUPPORT_ELF64
 468 void *Elf64Relocate(void *Base, char **envp, const char *Filename)
 469 {
 470          int    i;
 471         Elf64_Ehdr      *hdr = Base;
 472         Elf64_Phdr      *phtab;
 473         Elf64_Dyn       *dyntab;
 474         Elf64_Addr      compiledBase = -1, baseDiff;
 475         Elf64_Sym       *symtab = NULL;
 476         char    *strtab = NULL;
 477         Elf64_Word      *hashtab = NULL;
 478         Elf64_Rel       *rel = NULL;
 479          int    rel_count = 0;
 480         Elf64_Rela      *rela = NULL;
 481          int    rela_count = 0;
 482         void    *pltrel = NULL;
 483          int    plt_size = 0, plt_type = 0;
 484
 485         DEBUGS("Elf64Relocate: hdr = {");
 486         DEBUGS("Elf64Relocate:  e_ident = '%.16s'", hdr->e_ident);
 487         DEBUGS("Elf64Relocate:  e_type = 0x%x", hdr->e_type);
 488         DEBUGS("Elf64Relocate:  e_machine = 0x%x", hdr->e_machine);
 489         DEBUGS("Elf64Relocate:  e_version = 0x%x", hdr->e_version);
 490         DEBUGS("Elf64Relocate:  e_entry = %p", hdr->e_entry);
 491         DEBUGS("Elf64Relocate:  e_phoff = 0x%llx", hdr->e_phoff);
 492         DEBUGS("Elf64Relocate:  e_shoff = 0x%llx", hdr->e_shoff);
 493         DEBUGS("Elf64Relocate:  e_flags = 0x%x", hdr->e_flags);
 494         DEBUGS("Elf64Relocate:  e_ehsize = 0x%x", hdr->e_ehsize);
 495         DEBUGS("Elf64Relocate:  e_phentsize = 0x%x", hdr->e_phentsize);
 496         DEBUGS("Elf64Relocate:  e_phnum = %i", hdr->e_phnum);
 497
 498         // Scan for the dynamic table (and find the compiled base)
 499         phtab = Base + hdr->e_phoff;
 500         for( i = 0; i < hdr->e_phnum; i ++ )
 501         {
 502                 if(phtab[i].p_type == PT_DYNAMIC)
 503                         dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
 504                 if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
 505                         compiledBase = phtab[i].p_vaddr;
 506         }
 507
 508         baseDiff = (Elf64_Addr)Base - compiledBase;
 509
 510         DEBUGS("baseDiff = %p", baseDiff);
 511
 512         if(dyntab == NULL) {
 513                 SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 514                 return (void *)(hdr->e_entry + baseDiff);
 515         }
 516
 517         dyntab = (void *)((Elf64_Addr)dyntab + baseDiff);
 518
 519         // Parse the dynamic table (first pass)
 520         // - Search for String, Symbol and Hash tables
 521         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 522         {
 523                 switch(dyntab[i].d_tag)
 524                 {
 525                 case DT_SYMTAB:
 526                         dyntab[i].d_un.d_ptr += baseDiff;
 527                         symtab = (void *)dyntab[i].d_un.d_ptr;
 528                         break;
 529                 case DT_STRTAB:
 530                         dyntab[i].d_un.d_ptr += baseDiff;
 531                         strtab = (void *)dyntab[i].d_un.d_ptr;
 532                         break;
 533                 case DT_HASH:
 534                         dyntab[i].d_un.d_ptr += baseDiff;
 535                         hashtab = (void *)dyntab[i].d_un.d_ptr;
 536                         break;
 537                 }
 538         }
 539
 540         if( !symtab || !strtab || !hashtab ) {
 541                 SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
 542                 return NULL;
 543         }
 544
 545         // Ready for symbol use
 546         AddLoaded( Filename, Base );
 547
 548         // Second pass on dynamic table
 549         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 550         {
 551                 DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
 552                 switch(dyntab[i].d_tag)
 553                 {
 554                 case DT_SONAME: break;
 555
 556                 case DT_NEEDED: {
 557                         char *libPath = strtab + dyntab[i].d_un.d_val;
 558                         DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
 559                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 560                                 SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
 561                                 return NULL;
 562                         }
 563                         } break;
 564
 565                 // Relocation entries
 566                 case DT_REL:
 567                         dyntab[i].d_un.d_ptr += baseDiff;
 568                         rel = (void *)dyntab[i].d_un.d_ptr;
 569                         break;
 570                 case DT_RELSZ:
 571                         rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
 572                         break;
 573                 case DT_RELENT:
 574                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
 575                                 SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
 576                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
 577                                 return NULL;
 578                         }
 579                         break;
 580                 case DT_RELA:
 581                         dyntab[i].d_un.d_ptr += baseDiff;
 582                         rela = (void *)dyntab[i].d_un.d_ptr;
 583                         break;
 584                 case DT_RELASZ:
 585                         rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
 586                         break;
 587                 case DT_RELAENT:
 588                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
 589                                 SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
 590                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
 591                                 return NULL;
 592                         }
 593                         break;
 594                 case DT_JMPREL:
 595                         dyntab[i].d_un.d_ptr += baseDiff;
 596                         pltrel = (void *)dyntab[i].d_un.d_ptr;
 597                         break;
 598                 case DT_PLTREL:
 599                         plt_type = dyntab[i].d_un.d_val;
 600                         break;
 601                 case DT_PLTRELSZ:
 602                         plt_size = dyntab[i].d_un.d_val;
 603                         break;
 604                 }
 605         }
 606
 607         // Relocation function
 608         void _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
 609         {
 610                  int    sym = ELF64_R_SYM(r_info);
 611                  int    type = ELF64_R_TYPE(r_info);
 612                 const char      *symname = strtab + symtab[sym].st_name;
 613                 switch( type )
 614                 {
 615                 case R_X86_64_NONE:
 616                         break;
 617                 case R_X86_64_64:
 618                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname, NULL) + addend;
 619                         break;
 620                 case R_X86_64_COPY: {
 621                         size_t  size;
 622                         void    *sym = GetSymbol(symname, &size);
 623                         memcpy(ptr, sym, size);
 624                         } break;
 625                 case R_X86_64_GLOB_DAT:
 626                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname, NULL);
 627                         break;
 628                 case R_X86_64_JUMP_SLOT:
 629                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname, NULL);
 630                         break;
 631                 case R_X86_64_RELATIVE:
 632                         *(uint64_t*)ptr = (intptr_t)Base + addend;
 633                         break;
 634                 default:
 635                         SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
 636                         break;
 637                 }
 638         }
 639
 640         if( rel )
 641         {
 642                 DEBUGS("rel_count = %i", rel_count);
 643                 for( i = 0; i < rel_count; i ++ )
 644                 {
 645                         uint64_t *ptr = (void *)( rel[i].r_offset + baseDiff );
 646                         _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
 647                 }
 648         }
 649
 650         if( rela )
 651         {
 652                 DEBUGS("rela_count = %i", rela_count);
 653                 for( i = 0; i < rela_count; i ++ )
 654                 {
 655                         _Elf64DoReloc( rela[i].r_info, (void *)( rela[i].r_offset + baseDiff ), rela[i].r_addend );
 656                 }
 657         }
 658
 659         if( pltrel && plt_type )
 660         {
 661                 if( plt_type == DT_REL ) {
 662                         Elf64_Rel       *plt = pltrel;
 663                          int    count = plt_size / sizeof(Elf64_Rel);
 664                         DEBUGS("plt rel count = %i", count);
 665                         for( i = 0; i < count; i ++ )
 666                         {
 667                                 uint64_t *ptr = (void *)( plt[i].r_offset + baseDiff );
 668                                 _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
 669                         }
 670                 }
 671                 else {
 672                         Elf64_Rela      *plt = pltrel;
 673                          int    count = plt_size / sizeof(Elf64_Rela);
 674                         DEBUGS("plt rela count = %i", count);
 675                         for( i = 0; i < count; i ++ )
 676                         {
 677                                 _Elf64DoReloc( plt[i].r_info, (void *)(plt[i].r_offset + baseDiff), plt[i].r_addend);
 678                         }
 679                 }
 680         }
 681
 682         DEBUGS("Elf64Relocate: Relocations done, return %p", (void *)(hdr->e_entry + baseDiff));
 683         return (void *)(hdr->e_entry + baseDiff);
 684 }
 685
 686 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size)
 687 {
 688         Elf64_Ehdr      *hdr = Base;
 689         Elf64_Sym       *symtab;
 690          int    nbuckets = 0;
 691          int    iSymCount = 0;
 692          int    i;
 693         Elf64_Word      *pBuckets;
 694         Elf64_Word      *pChains;
 695         uint32_t        iNameHash;
 696         const char      *dynstrtab;
 697         uintptr_t       iBaseDiff = -1;
 698
 699         dynstrtab = NULL;
 700         pBuckets = NULL;
 701         symtab = NULL;
 702
 703         // Catch the current executable
 704         if( !pBuckets )
 705         {
 706                 Elf64_Phdr      *phtab;
 707                 Elf64_Dyn       *dynTab = NULL;
 708                  int    j;
 709
 710                 // Locate the tables
 711                 phtab = (void*)( Base + hdr->e_phoff );
 712                 for( i = 0; i < hdr->e_phnum; i ++ )
 713                 {
 714                         if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
 715                                 iBaseDiff = phtab[i].p_vaddr;
 716                         if( phtab[i].p_type == PT_DYNAMIC ) {
 717                                 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
 718                         }
 719                 }
 720                 if( !dynTab ) {
 721                         SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 722                         return 0;
 723                 }
 724                 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 725                 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 726
 727                 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
 728                 {
 729                         switch(dynTab[j].d_tag)
 730                         {
 731                         // --- Symbol Table ---
 732                         case DT_SYMTAB:
 733                                 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val;        // Rebased in Relocate
 734                                 break;
 735                         case DT_STRTAB:
 736                                 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
 737                                 break;
 738                         // --- Hash Table --
 739                         case DT_HASH:
 740                                 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
 741                                 break;
 742                         }
 743                 }
 744         }
 745
 746         nbuckets = pBuckets[0];
 747         iSymCount = pBuckets[1];
 748         pBuckets = &pBuckets[2];
 749         pChains = &pBuckets[ nbuckets ];
 750
 751         // Get hash
 752         iNameHash = ElfHashString(Name);
 753         iNameHash %= nbuckets;
 754
 755         // Walk Chain
 756         i = pBuckets[ iNameHash ];
 757         if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 758                 *Ret = (void*) (intptr_t) symtab[i].st_value + iBaseDiff;
 759                 if(Size)        *Size = symtab[i].st_size;
 760                 DEBUGS("%s = %p", Name, *Ret);
 761                 return 1;
 762         }
 763
 764         while(pChains[i] != STN_UNDEF)
 765         {
 766                 i = pChains[i];
 767                 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 768                         *Ret = (void*)(intptr_t)symtab[i].st_value + iBaseDiff;
 769                         if(Size)        *Size = symtab[i].st_size;
 770                         DEBUGS("%s = %p", Name, *Ret);
 771                         return 1;
 772                 }
 773         }
 774
 775         return 0;
 776 }
 777 #endif
 778
 779
 780 Uint32 ElfHashString(const char *name)
 781 {
 782         Uint32  h = 0, g;
 783         while(*name)
 784         {
 785                 h = (h << 4) + *(Uint8*)name++;
 786                 if( (g = h & 0xf0000000) )
 787                         h ^= g >> 24;
 788                 h &= ~g;
 789         }
 790         return h;
 791 }
 792