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

   1 /*
   2  * Acess2 Dynamic Linker
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * elf.c
   6  * - ELF32/ELF64 relocation
   7  */
   8 #ifndef DEBUG   // This code is #include'd from the kernel, so DEBUG may already be defined
   9 # define DEBUG  0
  10 #endif
  11
  12 #include "common.h"
  13 #include <stdint.h>
  14 #include "elf32.h"
  15 #include "elf64.h"
  16
  17 #if DEBUG
  18 # define        DEBUGS(v...)    SysDebug("ld-acess - " v)
  19 #else
  20 # define        DEBUGS(...)
  21 #endif
  22
  23 #ifndef DISABLE_ELF64
  24 # define SUPPORT_ELF64
  25 #endif
  26
  27 // === CONSTANTS ===
  28 #if DEBUG
  29 //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"};
  30 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"};
  31 #endif
  32
  33 // === PROTOTYPES ===
  34 void    *ElfRelocate(void *Base, char **envp, const char *Filename);
  35  int    ElfGetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  36 void    *Elf32Relocate(void *Base, char **envp, const char *Filename);
  37  int    Elf32GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  38 void    elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff);
  39 void    elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff);
  40 #ifdef SUPPORT_ELF64
  41 void    *Elf64Relocate(void *Base, char **envp, const char *Filename);
  42  int    Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  43 #endif
  44 uint32_t        ElfHashString(const char *name);
  45
  46 // === CODE ===
  47 /**
  48  * \fn int ElfRelocate(void *Base, char **envp, const char *Filename)
  49  * \brief Relocates a loaded ELF Executable
  50  */
  51 void *ElfRelocate(void *Base, char **envp, const char *Filename)
  52 {
  53         Elf32_Ehdr      *hdr = Base;
  54
  55         switch(hdr->e_ident[4])
  56         {
  57         case ELFCLASS32:
  58                 return Elf32Relocate(Base, envp, Filename);
  59 #ifdef SUPPORT_ELF64
  60         case ELFCLASS64:
  61                 return Elf64Relocate(Base, envp, Filename);
  62 #endif
  63         default:
  64                 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
  65                 return NULL;
  66         }
  67 }
  68
  69 /**
  70  * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
  71  */
  72 int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
  73 {
  74         Elf32_Ehdr      *hdr = Base;
  75
  76         switch(hdr->e_ident[4])
  77         {
  78         case ELFCLASS32:
  79                 return Elf32GetSymbol(Base, Name, ret, Size);
  80 #ifdef SUPPORT_ELF64
  81         case ELFCLASS64:
  82                 return Elf64GetSymbol(Base, Name, ret, Size);
  83 #endif
  84         default:
  85                 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
  86                 return 0;
  87         }
  88 }
  89
  90 void elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
  91 {
  92         intptr_t        val;
  93         switch( type )
  94         {
  95         // Standard 32 Bit Relocation (S+A)
  96         case R_386_32:
  97                 val = (intptr_t) GetSymbol(Sym, NULL);
  98                 DEBUGS(" elf_doRelocate: R_386_32 *0x%x += 0x%x('%s')",
  99                                 ptr, val, Sym);
 100                 *ptr = val + addend;
 101                 break;
 102
 103         // 32 Bit Relocation wrt. Offset (S+A-P)
 104         case R_386_PC32:
 105                 DEBUGS(" elf_doRelocate: '%s'", Sym);
 106                 val = (intptr_t) GetSymbol(Sym, NULL);
 107                 DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%x - 0x%x",
 108                         ptr, *ptr, val, (intptr_t)ptr );
 109                 *ptr = val + addend - (intptr_t)ptr;
 110                 //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
 111                 break;
 112
 113         // Absolute Value of a symbol (S)
 114         case R_386_GLOB_DAT:
 115         case R_386_JMP_SLOT:
 116                 DEBUGS(" elf_doRelocate: '%s'", Sym);
 117                 val = (intptr_t) GetSymbol( Sym, NULL );
 118                 DEBUGS(" elf_doRelocate: %s *0x%x = 0x%x", csaR_NAMES[type], ptr, val);
 119                 *ptr = val;
 120                 break;
 121
 122         // Base Address (B+A)
 123         case R_386_RELATIVE:
 124                 DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
 125                 *ptr = iBaseDiff + addend;
 126                 break;
 127
 128         case R_386_COPY: {
 129                 size_t  size;
 130                 void    *src = GetSymbol(Sym, &size);
 131                 DEBUGS(" elf_doRelocate_386: R_386_COPY (%p, %p, %i)", ptr, src, size);
 132                 memcpy(ptr, src, size);
 133                 break; }
 134
 135         default:
 136                 SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
 137                 break;
 138         }
 139 }
 140
 141 void elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
 142 {
 143         uint32_t        val;
 144         switch(type)
 145         {
 146         // (S + A) | T
 147         case R_ARM_ABS32:
 148                 DEBUGS(" elf_doRelocate_arm: R_ARM_ABS32 %p (%s + %x)", ptr, Sym, addend);
 149                 val = (intptr_t)GetSymbol(Sym, NULL);
 150                 *ptr = val + addend;
 151                 break;
 152         case R_ARM_GLOB_DAT:
 153                 DEBUGS(" elf_doRelocate_arm: R_ARM_GLOB_DAT %p (%s + %x)", ptr, Sym, addend);
 154                 val = (intptr_t)GetSymbol(Sym, NULL);
 155                 *ptr = val + addend;
 156                 break;
 157         case R_ARM_JUMP_SLOT:
 158                 if(!bRela)      addend = 0;
 159                 DEBUGS(" elf_doRelocate_arm: R_ARM_JUMP_SLOT %p (%s + %x)", ptr, Sym, addend);
 160                 val = (intptr_t)GetSymbol(Sym, NULL);
 161                 *ptr = val + addend;
 162                 break;
 163         // Copy
 164         case R_ARM_COPY: {
 165                 size_t  size;
 166                 void    *src = GetSymbol(Sym, &size);
 167                 DEBUGS(" elf_doRelocate_arm: R_ARM_COPY (%p, %p, %i)", ptr, src, size);
 168                 memcpy(ptr, src, size);
 169                 break; }
 170         // Delta between link and runtime locations + A
 171         case R_ARM_RELATIVE:
 172                 if(Sym[0] != '\0') {
 173                         // TODO: Get delta for a symbol
 174                         SysDebug("elf_doRelocate_arm: TODO - Implment R_ARM_RELATIVE for symbols");
 175                 }
 176                 else {
 177                         *ptr = iBaseDiff + addend;
 178                 }
 179                 break;
 180         default:
 181                 SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
 182                 break;
 183         }
 184 }
 185
 186 void *Elf32Relocate(void *Base, char **envp, const char *Filename)
 187 {
 188         Elf32_Ehdr      *hdr = Base;
 189         Elf32_Phdr      *phtab;
 190          int    i, j;   // Counters
 191         char    *libPath;
 192         intptr_t        iRealBase = -1;
 193         intptr_t        iBaseDiff;
 194          int    iSegmentCount;
 195 //       int    iSymCount;
 196         Elf32_Rel       *rel = NULL;
 197         Elf32_Rela      *rela = NULL;
 198         void    *plt = NULL;
 199          int    relSz=0, relEntSz=8;
 200          int    relaSz=0, relaEntSz=8;
 201          int    pltSz=0, pltType=0;
 202         Elf32_Dyn       *dynamicTab = NULL;     // Dynamic Table Pointer
 203         char    *dynstrtab = NULL;      // .dynamic String Table
 204         Elf32_Sym       *dynsymtab;
 205         void    (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, int bRela, const char *Sym, intptr_t iBaseDiff);
 206         auto void _doRelocate(uint32_t r_info, uint32_t *ptr, int bRela, Elf32_Addr addend);
 207
 208         DEBUGS("ElfRelocate: (Base=0x%x)", Base);
 209
 210         // Check magic header
 211
 212
 213         // Parse Program Header to get Dynamic Table
 214         phtab = (void*)( (uintptr_t)Base + hdr->phoff );
 215         iSegmentCount = hdr->phentcount;
 216         for(i=0;i<iSegmentCount;i++)
 217         {
 218                 // Determine linked base address
 219                 if(phtab[i].Type == PT_LOAD && iRealBase > phtab[i].VAddr)
 220                         iRealBase = phtab[i].VAddr;
 221
 222                 // Find Dynamic Section
 223                 if(phtab[i].Type == PT_DYNAMIC) {
 224                         if(dynamicTab) {
 225                                 DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
 226                                 continue;
 227                         }
 228                         dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
 229                         j = i;  // Save Dynamic Table ID
 230                 }
 231         }
 232
 233         // Page Align real base
 234         iRealBase &= ~0xFFF;
 235         DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
 236
 237         // Adjust "Real" Base
 238         iBaseDiff = (intptr_t)Base - iRealBase;
 239
 240 //      hdr->entrypoint += iBaseDiff;   // Adjust Entrypoint
 241
 242         // Check if a PT_DYNAMIC segement was found
 243         if(!dynamicTab) {
 244                 SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 245                 return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
 246         }
 247
 248         // Adjust Dynamic Table
 249         dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
 250
 251         // === Get Symbol table and String Table ===
 252         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 253         {
 254                 switch(dynamicTab[j].d_tag)
 255                 {
 256                 // --- Symbol Table ---
 257                 case DT_SYMTAB:
 258                         DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
 259                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 260                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 261                         dynsymtab = (void*)(intptr_t)dynamicTab[j].d_val;
 262                         break;
 263                 // --- String Table ---
 264                 case DT_STRTAB:
 265                         DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
 266                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 267                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 268                         dynstrtab = (void*)(intptr_t)dynamicTab[j].d_val;
 269                         break;
 270                 // --- Hash Table --
 271                 case DT_HASH:
 272                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 273 //                      iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
 274                         break;
 275                 }
 276         }
 277
 278         if(dynsymtab == NULL) {
 279                 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
 280                 return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
 281         }
 282
 283         // === Add to loaded list (can be imported now) ===
 284         AddLoaded( Filename, Base );
 285
 286         // === Parse Relocation Data ===
 287         DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
 288         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 289         {
 290                 switch(dynamicTab[j].d_tag)
 291                 {
 292                 // --- Shared Library Name ---
 293                 case DT_SONAME:
 294                         DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
 295                         break;
 296                 // --- Needed Library ---
 297                 case DT_NEEDED:
 298                         libPath = dynstrtab + dynamicTab[j].d_val;
 299                         DEBUGS(" Required Library '%s'", libPath);
 300                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 301                                 #if DEBUG
 302                                 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
 303                                 #else
 304                                 SysDebug("Unable to load required library '%s'", libPath);
 305                                 #endif
 306                                 return 0;
 307                         }
 308                         DEBUGS(" Lib loaded");
 309                         break;
 310                 // --- PLT/GOT ---
 311 //              case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val);      break;
 312                 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 313                 case DT_PLTREL: pltType = dynamicTab[j].d_val;  break;
 314                 case DT_PLTRELSZ:       pltSz = dynamicTab[j].d_val;    break;
 315
 316                 // --- Relocation ---
 317                 case DT_REL:    rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 318                 case DT_RELSZ:  relSz = dynamicTab[j].d_val;    break;
 319                 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
 320                 case DT_RELA:   rela = (void*)(iBaseDiff + dynamicTab[j].d_val);        break;
 321                 case DT_RELASZ: relaSz = dynamicTab[j].d_val;   break;
 322                 case DT_RELAENT:        relaEntSz = dynamicTab[j].d_val;        break;
 323
 324                 // --- Symbol Table ---
 325                 case DT_SYMTAB:
 326                 // --- Hash Table ---
 327                 case DT_HASH:
 328                 // --- String Table ---
 329                 case DT_STRTAB:
 330                         break;
 331
 332                 // --- Unknown ---
 333                 default:
 334                         if(dynamicTab[j].d_tag > DT_JMPREL)     continue;
 335                         //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
 336                         //      i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
 337                         break;
 338                 }
 339         }
 340
 341         DEBUGS(" elf_relocate: Beginning Relocation");
 342
 343         void _doRelocate(uint32_t r_info, uint32_t *ptr, int bRela, Elf32_Addr addend)
 344         {
 345                  int    type = ELF32_R_TYPE(r_info);
 346                  int    sym = ELF32_R_SYM(r_info);
 347                 const char      *symname = dynstrtab + dynsymtab[sym].nameOfs;
 348                 do_relocate(r_info, ptr, addend, type, bRela, symname, iBaseDiff);
 349         }
 350
 351         switch(hdr->machine)
 352         {
 353         case EM_386:
 354                 do_relocate = elf_doRelocate_386;
 355                 break;
 356         case EM_ARM:
 357                 do_relocate = elf_doRelocate_arm;
 358                 break;
 359         default:
 360                 SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
 361                 break;
 362         }
 363
 364         DEBUGS("do_relocate = %p (%p or %p)", do_relocate, &elf_doRelocate_386, &elf_doRelocate_arm);
 365
 366         // Parse Relocation Entries
 367         if(rel && relSz)
 368         {
 369                 Elf32_Word      *ptr;
 370                 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
 371                 j = relSz / relEntSz;
 372                 for( i = 0; i < j; i++ )
 373                 {
 374                         //DEBUGS("  Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
 375                         ptr = (void*)(iBaseDiff + rel[i].r_offset);
 376                         _doRelocate(rel[i].r_info, ptr, 0, *ptr);
 377                 }
 378         }
 379         // Parse Relocation Entries
 380         if(rela && relaSz)
 381         {
 382                 Elf32_Word      *ptr;
 383                 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
 384                 j = relaSz / relaEntSz;
 385                 for( i = 0; i < j; i++ )
 386                 {
 387                         ptr = (void*)(iBaseDiff + rela[i].r_offset);
 388                         _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend);
 389                 }
 390         }
 391
 392         // === Process PLT (Procedure Linkage Table) ===
 393         if(plt && pltSz)
 394         {
 395                 Elf32_Word      *ptr;
 396                 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
 397                 if(pltType == DT_REL)
 398                 {
 399                         Elf32_Rel       *pltRel = plt;
 400                         j = pltSz / sizeof(Elf32_Rel);
 401                         DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", j);
 402                         for(i=0;i<j;i++)
 403                         {
 404                                 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
 405                                 _doRelocate(pltRel[i].r_info, ptr, 0, *ptr);
 406                         }
 407                 }
 408                 else
 409                 {
 410                         Elf32_Rela      *pltRela = plt;
 411                         j = pltSz / sizeof(Elf32_Rela);
 412                         DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", j);
 413                         for(i=0;i<j;i++)
 414                         {
 415                                 ptr = (void*)(iRealBase + pltRela[i].r_offset);
 416                                 _doRelocate(pltRela[i].r_info, ptr, 1, pltRela[i].r_addend);
 417                         }
 418                 }
 419         }
 420
 421         DEBUGS("ElfRelocate: RETURN 0x%x to %p", hdr->entrypoint + iBaseDiff, __builtin_return_address(0));
 422         return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff );
 423 }
 424
 425 int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
 426 {
 427         Elf32_Ehdr      *hdr = Base;
 428         Elf32_Sym       *symtab = NULL;
 429          int    nbuckets = 0;
 430         Elf32_Word      *pBuckets = NULL;
 431         Elf32_Word      *pChains;
 432         uint32_t        iNameHash;
 433         const char      *dynstrtab = NULL;
 434         uintptr_t       iBaseDiff = -1;
 435         Elf32_Phdr      *phtab;
 436         Elf32_Dyn       *dynTab = NULL;
 437          int    i;
 438
 439         // Locate the tables
 440         phtab = (void*)( (uintptr_t)Base + hdr->phoff );
 441         for( i = 0; i < hdr->phentcount; i ++ )
 442         {
 443                 if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
 444                         iBaseDiff = phtab[i].VAddr;
 445                 if( phtab[i].Type == PT_DYNAMIC ) {
 446                         dynTab = (void*)(intptr_t)phtab[i].VAddr;
 447                 }
 448         }
 449         if( !dynTab ) {
 450                 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 451                 return 0;
 452         }
 453         iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 454         dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 455         for( i = 0; dynTab[i].d_tag != DT_NULL; i++)
 456         {
 457                 switch(dynTab[i].d_tag)
 458                 {
 459                 // --- Symbol Table ---
 460                 case DT_SYMTAB:
 461                         symtab = (void*)(intptr_t) dynTab[i].d_val;     // Rebased in Relocate
 462                         break;
 463                 case DT_STRTAB:
 464                         dynstrtab = (void*)(intptr_t) dynTab[i].d_val;
 465                         break;
 466                 // --- Hash Table --
 467                 case DT_HASH:
 468                         pBuckets = (void*)(intptr_t) dynTab[i].d_val;
 469                         break;
 470                 }
 471         }
 472
 473         if( !symtab ) {
 474                 SysDebug("ERRO - No DT_SYMTAB in %p", Base);
 475                 return 0;
 476         }
 477         if( !pBuckets ) {
 478                 SysDebug("ERRO - No DT_HASH in %p", Base);
 479                 return 0;
 480         }
 481         if( !dynstrtab ) {
 482                 SysDebug("ERRO - No DT_STRTAB in %p", Base);
 483                 return 0;
 484         }
 485
 486         // ... ok... maybe they haven't been relocated
 487         if( (uintptr_t)symtab < (uintptr_t)Base )
 488         {
 489                 symtab    = (void*)( (uintptr_t)symtab    + iBaseDiff );
 490                 pBuckets  = (void*)( (uintptr_t)pBuckets  + iBaseDiff );
 491                 dynstrtab = (void*)( (uintptr_t)dynstrtab + iBaseDiff );
 492                 SysDebug("Executable not yet relocated");
 493         }
 494
 495         nbuckets = pBuckets[0];
 496 //      iSymCount = pBuckets[1];
 497         pBuckets = &pBuckets[2];
 498         pChains = &pBuckets[ nbuckets ];
 499
 500         // Get hash
 501         iNameHash = ElfHashString(Name);
 502         iNameHash %= nbuckets;
 503
 504         // Walk Chain
 505         i = pBuckets[ iNameHash ];
 506         if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
 507                 *ret = (void*)( (uintptr_t) symtab[ i ].value + iBaseDiff );
 508                 if(Size)        *Size = symtab[i].size;
 509                 return 1;
 510         }
 511
 512         while(pChains[i] != STN_UNDEF)
 513         {
 514                 i = pChains[i];
 515                 if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
 516                         *ret = (void*)( (uintptr_t)symtab[ i ].value + iBaseDiff );
 517                         if(Size)        *Size = symtab[i].size;
 518                         return 1;
 519                 }
 520         }
 521
 522         return 0;
 523 }
 524
 525 #ifdef SUPPORT_ELF64
 526 void *Elf64Relocate(void *Base, char **envp, const char *Filename)
 527 {
 528          int    i;
 529         Elf64_Ehdr      *hdr = Base;
 530         Elf64_Phdr      *phtab;
 531         Elf64_Dyn       *dyntab;
 532         Elf64_Addr      compiledBase = -1, baseDiff;
 533         Elf64_Sym       *symtab = NULL;
 534         char    *strtab = NULL;
 535         Elf64_Word      *hashtab = NULL;
 536         Elf64_Rel       *rel = NULL;
 537          int    rel_count = 0;
 538         Elf64_Rela      *rela = NULL;
 539          int    rela_count = 0;
 540         void    *pltrel = NULL;
 541          int    plt_size = 0, plt_type = 0;
 542
 543         DEBUGS("Elf64Relocate: hdr = {");
 544         DEBUGS("Elf64Relocate:  e_ident = '%.16s'", hdr->e_ident);
 545         DEBUGS("Elf64Relocate:  e_type = 0x%x", hdr->e_type);
 546         DEBUGS("Elf64Relocate:  e_machine = 0x%x", hdr->e_machine);
 547         DEBUGS("Elf64Relocate:  e_version = 0x%x", hdr->e_version);
 548         DEBUGS("Elf64Relocate:  e_entry = %p", hdr->e_entry);
 549         DEBUGS("Elf64Relocate:  e_phoff = 0x%llx", hdr->e_phoff);
 550         DEBUGS("Elf64Relocate:  e_shoff = 0x%llx", hdr->e_shoff);
 551         DEBUGS("Elf64Relocate:  e_flags = 0x%x", hdr->e_flags);
 552         DEBUGS("Elf64Relocate:  e_ehsize = 0x%x", hdr->e_ehsize);
 553         DEBUGS("Elf64Relocate:  e_phentsize = 0x%x", hdr->e_phentsize);
 554         DEBUGS("Elf64Relocate:  e_phnum = %i", hdr->e_phnum);
 555
 556         // Scan for the dynamic table (and find the compiled base)
 557         phtab = Base + hdr->e_phoff;
 558         for( i = 0; i < hdr->e_phnum; i ++ )
 559         {
 560                 if(phtab[i].p_type == PT_DYNAMIC)
 561                         dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
 562                 if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
 563                         compiledBase = phtab[i].p_vaddr;
 564         }
 565
 566         baseDiff = (uintptr_t)Base - compiledBase;
 567
 568         DEBUGS("baseDiff = %p", baseDiff);
 569
 570         if(dyntab == NULL) {
 571                 SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 572                 return (void *)(uintptr_t)(hdr->e_entry + baseDiff);
 573         }
 574
 575         dyntab = (void *)(uintptr_t)((uintptr_t)dyntab + baseDiff);
 576
 577         // Parse the dynamic table (first pass)
 578         // - Search for String, Symbol and Hash tables
 579         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 580         {
 581                 switch(dyntab[i].d_tag)
 582                 {
 583                 case DT_SYMTAB:
 584                         dyntab[i].d_un.d_ptr += baseDiff;
 585                         symtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 586                         break;
 587                 case DT_STRTAB:
 588                         dyntab[i].d_un.d_ptr += baseDiff;
 589                         strtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 590                         break;
 591                 case DT_HASH:
 592                         dyntab[i].d_un.d_ptr += baseDiff;
 593                         hashtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 594                         break;
 595                 }
 596         }
 597
 598         if( !symtab || !strtab || !hashtab ) {
 599                 SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
 600                 return NULL;
 601         }
 602
 603         // Ready for symbol use
 604         AddLoaded( Filename, Base );
 605
 606         // Second pass on dynamic table
 607         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 608         {
 609                 DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
 610                 switch(dyntab[i].d_tag)
 611                 {
 612                 case DT_SONAME: break;
 613
 614                 case DT_NEEDED: {
 615                         char *libPath = strtab + dyntab[i].d_un.d_val;
 616                         DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
 617                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 618                                 SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
 619                                 return NULL;
 620                         }
 621                         } break;
 622
 623                 // Relocation entries
 624                 case DT_REL:
 625                         dyntab[i].d_un.d_ptr += baseDiff;
 626                         rel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 627                         break;
 628                 case DT_RELSZ:
 629                         rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
 630                         break;
 631                 case DT_RELENT:
 632                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
 633                                 SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
 634                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
 635                                 return NULL;
 636                         }
 637                         break;
 638                 case DT_RELA:
 639                         dyntab[i].d_un.d_ptr += baseDiff;
 640                         rela = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 641                         break;
 642                 case DT_RELASZ:
 643                         rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
 644                         break;
 645                 case DT_RELAENT:
 646                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
 647                                 SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
 648                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
 649                                 return NULL;
 650                         }
 651                         break;
 652                 case DT_JMPREL:
 653                         dyntab[i].d_un.d_ptr += baseDiff;
 654                         pltrel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 655                         break;
 656                 case DT_PLTREL:
 657                         plt_type = dyntab[i].d_un.d_val;
 658                         break;
 659                 case DT_PLTRELSZ:
 660                         plt_size = dyntab[i].d_un.d_val;
 661                         break;
 662                 }
 663         }
 664
 665         // Relocation function
 666         void _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
 667         {
 668                  int    sym = ELF64_R_SYM(r_info);
 669                  int    type = ELF64_R_TYPE(r_info);
 670                 const char      *symname = strtab + symtab[sym].st_name;
 671                 switch( type )
 672                 {
 673                 case R_X86_64_NONE:
 674                         break;
 675                 case R_X86_64_64:
 676                         *(uint64_t*)ptr = (uintptr_t)GetSymbol(symname, NULL) + addend;
 677                         break;
 678                 case R_X86_64_COPY: {
 679                         size_t  size;
 680                         void    *sym = GetSymbol(symname, &size);
 681                         memcpy(ptr, sym, size);
 682                         } break;
 683                 case R_X86_64_GLOB_DAT:
 684                         *(uint64_t*)ptr = (uintptr_t)GetSymbol(symname, NULL);
 685                         break;
 686                 case R_X86_64_JUMP_SLOT:
 687                         *(uint64_t*)ptr = (uintptr_t)GetSymbol(symname, NULL);
 688                         break;
 689                 case R_X86_64_RELATIVE:
 690                         *(uint64_t*)ptr = (uintptr_t)Base + addend;
 691                         break;
 692                 default:
 693                         SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
 694                         break;
 695                 }
 696         }
 697
 698         if( rel )
 699         {
 700                 DEBUGS("rel_count = %i", rel_count);
 701                 for( i = 0; i < rel_count; i ++ )
 702                 {
 703                         uint64_t *ptr = (void *)(uintptr_t)( rel[i].r_offset + baseDiff );
 704                         _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
 705                 }
 706         }
 707
 708         if( rela )
 709         {
 710                 DEBUGS("rela_count = %i", rela_count);
 711                 for( i = 0; i < rela_count; i ++ )
 712                 {
 713                         uint64_t *ptr = (void *)(uintptr_t)( rela[i].r_offset + baseDiff );
 714                         _Elf64DoReloc( rela[i].r_info, ptr, rela[i].r_addend );
 715                 }
 716         }
 717
 718         if( pltrel && plt_type )
 719         {
 720                 if( plt_type == DT_REL ) {
 721                         Elf64_Rel       *plt = pltrel;
 722                          int    count = plt_size / sizeof(Elf64_Rel);
 723                         DEBUGS("plt rel count = %i", count);
 724                         for( i = 0; i < count; i ++ )
 725                         {
 726                                 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
 727                                 _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
 728                         }
 729                 }
 730                 else {
 731                         Elf64_Rela      *plt = pltrel;
 732                          int    count = plt_size / sizeof(Elf64_Rela);
 733                         DEBUGS("plt rela count = %i", count);
 734                         for( i = 0; i < count; i ++ )
 735                         {
 736                                 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
 737                                 _Elf64DoReloc( plt[i].r_info, ptr, plt[i].r_addend);
 738                         }
 739                 }
 740         }
 741
 742         {
 743         void *ret = (void *)(uintptr_t)(hdr->e_entry + baseDiff);
 744         DEBUGS("Elf64Relocate: Relocations done, return %p", ret);
 745         return ret;
 746         }
 747 }
 748
 749 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size)
 750 {
 751         Elf64_Ehdr      *hdr = Base;
 752         Elf64_Sym       *symtab;
 753          int    nbuckets = 0;
 754 //       int    iSymCount = 0;
 755          int    i;
 756         Elf64_Word      *pBuckets;
 757         Elf64_Word      *pChains;
 758         uint32_t        iNameHash;
 759         const char      *dynstrtab;
 760         uintptr_t       iBaseDiff = -1;
 761
 762         dynstrtab = NULL;
 763         pBuckets = NULL;
 764         symtab = NULL;
 765
 766         // Catch the current executable
 767         if( !pBuckets )
 768         {
 769                 Elf64_Phdr      *phtab;
 770                 Elf64_Dyn       *dynTab = NULL;
 771                  int    j;
 772
 773                 // Locate the tables
 774                 phtab = (void*)( (intptr_t)Base + hdr->e_phoff );
 775                 for( i = 0; i < hdr->e_phnum; i ++ )
 776                 {
 777                         if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
 778                                 iBaseDiff = phtab[i].p_vaddr;
 779                         if( phtab[i].p_type == PT_DYNAMIC ) {
 780                                 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
 781                         }
 782                 }
 783                 if( !dynTab ) {
 784                         SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 785                         return 0;
 786                 }
 787                 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 788                 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 789
 790                 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
 791                 {
 792                         switch(dynTab[j].d_tag)
 793                         {
 794                         // --- Symbol Table ---
 795                         case DT_SYMTAB:
 796                                 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val;        // Rebased in Relocate
 797                                 break;
 798                         case DT_STRTAB:
 799                                 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
 800                                 break;
 801                         // --- Hash Table --
 802                         case DT_HASH:
 803                                 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
 804                                 break;
 805                         }
 806                 }
 807         }
 808
 809         nbuckets = pBuckets[0];
 810 //      iSymCount = pBuckets[1];
 811         pBuckets = &pBuckets[2];
 812         pChains = &pBuckets[ nbuckets ];
 813
 814         // Get hash
 815         iNameHash = ElfHashString(Name);
 816         iNameHash %= nbuckets;
 817
 818         // Walk Chain
 819         i = pBuckets[ iNameHash ];
 820         if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 821                 *Ret = (void*)( (intptr_t)symtab[i].st_value + iBaseDiff );
 822                 if(Size)        *Size = symtab[i].st_size;
 823                 DEBUGS("%s = %p", Name, *Ret);
 824                 return 1;
 825         }
 826
 827         while(pChains[i] != STN_UNDEF)
 828         {
 829                 i = pChains[i];
 830                 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 831                         *Ret = (void*)((intptr_t)symtab[i].st_value + iBaseDiff);
 832                         if(Size)        *Size = symtab[i].st_size;
 833                         DEBUGS("%s = %p", Name, *Ret);
 834                         return 1;
 835                 }
 836         }
 837
 838         return 0;
 839 }
 840 #endif
 841
 842
 843 uint32_t ElfHashString(const char *name)
 844 {
 845         uint32_t        h = 0, g;
 846         while(*name)
 847         {
 848                 h = (h << 4) + *(uint8_t*)name++;
 849                 if( (g = h & 0xf0000000) )
 850                         h ^= g >> 24;
 851                 h &= ~g;
 852         }
 853         return h;
 854 }
 855