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