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 #ifndef PAGE_SIZE
  13 # define PAGE_SIZE      4096
  14 #endif
  15
  16 #include "common.h"
  17 #include <stdint.h>
  18 #include "elf32.h"
  19 #include "elf64.h"
  20
  21 #if DEBUG
  22 # define        DEBUGS(v...)    SysDebug("ld-acess - " v)
  23 #else
  24 # define        DEBUGS(...)
  25 #endif
  26
  27 #ifndef DISABLE_ELF64
  28 # define SUPPORT_ELF64
  29 #endif
  30
  31 // === CONSTANTS ===
  32 #if DEBUG
  33 //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"};
  34 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"};
  35 #endif
  36
  37 // === PROTOTYPES ===
  38 void    *ElfRelocate(void *Base, char **envp, const char *Filename);
  39  int    ElfGetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  40 void    *Elf32Relocate(void *Base, char **envp, const char *Filename);
  41  int    Elf32GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  42  int    elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff);
  43  int    elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff);
  44  int    elf_doRelocate_unk(uint32_t , uint32_t *, Elf32_Addr , int , int , const char *, intptr_t);
  45 #ifdef SUPPORT_ELF64
  46 void    *Elf64Relocate(void *Base, char **envp, const char *Filename);
  47  int    Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
  48 #endif
  49 uint32_t        ElfHashString(const char *name);
  50
  51 // === CODE ===
  52 /**
  53  * \fn int ElfRelocate(void *Base, char **envp, const char *Filename)
  54  * \brief Relocates a loaded ELF Executable
  55  */
  56 void *ElfRelocate(void *Base, char **envp, const char *Filename)
  57 {
  58         Elf32_Ehdr      *hdr = Base;
  59
  60         switch(hdr->e_ident[4])
  61         {
  62         case ELFCLASS32:
  63                 return Elf32Relocate(Base, envp, Filename);
  64 #ifdef SUPPORT_ELF64
  65         case ELFCLASS64:
  66                 return Elf64Relocate(Base, envp, Filename);
  67 #endif
  68         default:
  69                 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
  70                 return NULL;
  71         }
  72 }
  73
  74 /**
  75  * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
  76  */
  77 int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
  78 {
  79         Elf32_Ehdr      *hdr = Base;
  80
  81         switch(hdr->e_ident[4])
  82         {
  83         case ELFCLASS32:
  84                 return Elf32GetSymbol(Base, Name, ret, Size);
  85 #ifdef SUPPORT_ELF64
  86         case ELFCLASS64:
  87                 return Elf64GetSymbol(Base, Name, ret, Size);
  88 #endif
  89         default:
  90                 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
  91                 return 0;
  92         }
  93 }
  94
  95 int elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type,
  96                 int bRela, const char *Sym, intptr_t iBaseDiff)
  97 {
  98         void    *symval;
  99         switch( type )
 100         {
 101         // Standard 32 Bit Relocation (S+A)
 102         case R_386_32:
 103                 if( !GetSymbol(Sym, &symval, NULL) )
 104                         return 1;
 105                 DEBUGS(" elf_doRelocate: R_386_32 *0x%x += %p('%s')",
 106                                 ptr, symval, Sym);
 107                 *ptr = (intptr_t)symval + addend;
 108                 break;
 109
 110         // 32 Bit Relocation wrt. Offset (S+A-P)
 111         case R_386_PC32:
 112                 DEBUGS(" elf_doRelocate: '%s'", Sym);
 113                 if( !GetSymbol(Sym, &symval, NULL) )    return 1;
 114                 DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%p - 0x%x",
 115                         ptr, *ptr, symval, (intptr_t)ptr );
 116                 *ptr = (intptr_t)symval + addend - (intptr_t)ptr;
 117                 //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
 118                 break;
 119
 120         // Absolute Value of a symbol (S)
 121         case R_386_GLOB_DAT:
 122         case R_386_JMP_SLOT:
 123                 DEBUGS(" elf_doRelocate: '%s'", Sym);
 124                 if( !GetSymbol(Sym, &symval, NULL) )    return 1;
 125                 DEBUGS(" elf_doRelocate: %s *0x%x = %p", csaR_NAMES[type], ptr, symval);
 126                 *ptr = (intptr_t)symval;
 127                 break;
 128
 129         // Base Address (B+A)
 130         case R_386_RELATIVE:
 131                 DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
 132                 *ptr = iBaseDiff + addend;
 133                 break;
 134
 135         case R_386_COPY: {
 136                 size_t  size;
 137                 if( !GetSymbol(Sym, &symval, &size) )   return 1;
 138                 DEBUGS(" elf_doRelocate_386: R_386_COPY (%p, %p, %i)", ptr, symval, size);
 139                 memcpy(ptr, symval, size);
 140                 break; }
 141
 142         default:
 143                 SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
 144                 return 2;
 145         }
 146         return 0;
 147 }
 148
 149 int elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
 150 {
 151         uint32_t        val;
 152         switch(type)
 153         {
 154         // (S + A) | T
 155         case R_ARM_ABS32:
 156                 DEBUGS(" elf_doRelocate_arm: R_ARM_ABS32 %p (%s + %x)", ptr, Sym, addend);
 157                 if( !GetSymbol(Sym, (void**)&val, NULL) )       return 1;
 158                 *ptr = val + addend;
 159                 break;
 160         case R_ARM_GLOB_DAT:
 161                 DEBUGS(" elf_doRelocate_arm: R_ARM_GLOB_DAT %p (%s + %x)", ptr, Sym, addend);
 162                 if( !GetSymbol(Sym, (void**)&val, NULL) )       return 1;
 163                 *ptr = val + addend;
 164                 break;
 165         case R_ARM_JUMP_SLOT:
 166                 if(!bRela)      addend = 0;
 167                 DEBUGS(" elf_doRelocate_arm: R_ARM_JUMP_SLOT %p (%s + %x)", ptr, Sym, addend);
 168                 if( !GetSymbol(Sym, (void**)&val, NULL) )       return 1;
 169                 *ptr = val + addend;
 170                 break;
 171         // Copy
 172         case R_ARM_COPY: {
 173                 size_t  size;
 174                 void    *src;
 175                 if( !GetSymbol(Sym, &src, &size) )      return 1;
 176                 DEBUGS(" elf_doRelocate_arm: R_ARM_COPY (%p, %p, %i)", ptr, src, size);
 177                 memcpy(ptr, src, size);
 178                 break; }
 179         // Delta between link and runtime locations + A
 180         case R_ARM_RELATIVE:
 181                 DEBUGS(" elf_doRelocate_arm: R_ARM_RELATIVE %p (0x%x + 0x%x)", ptr, iBaseDiff, addend);
 182                 if(Sym[0] != '\0') {
 183                         // TODO: Get delta for a symbol
 184                         SysDebug("elf_doRelocate_arm: TODO - Implment R_ARM_RELATIVE for symbols");
 185                         return 2;
 186                 }
 187                 else {
 188                         *ptr = iBaseDiff + addend;
 189                 }
 190                 break;
 191         default:
 192                 SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
 193                 return 2;
 194         }
 195         return 0;
 196 }
 197
 198 int elf_doRelocate_unk(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
 199 {
 200         return 1;
 201 }
 202
 203 void *Elf32Relocate(void *Base, char **envp, const char *Filename)
 204 {
 205         Elf32_Ehdr      *hdr = Base;
 206         Elf32_Phdr      *phtab;
 207          int    i, j;   // Counters
 208         char    *libPath;
 209         intptr_t        iRealBase = -1;
 210         intptr_t        iBaseDiff;
 211          int    iSegmentCount;
 212 //       int    iSymCount;
 213         Elf32_Rel       *rel = NULL;
 214         Elf32_Rela      *rela = NULL;
 215         void    *plt = NULL;
 216          int    relSz=0, relEntSz=8;
 217          int    relaSz=0, relaEntSz=8;
 218          int    pltSz=0, pltType=0;
 219         Elf32_Dyn       *dynamicTab = NULL;     // Dynamic Table Pointer
 220         char    *dynstrtab = NULL;      // .dynamic String Table
 221         Elf32_Sym       *dynsymtab;
 222         int     (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, int bRela, const char *Sym, intptr_t iBaseDiff);
 223
 224         DEBUGS("ElfRelocate: (Base=0x%x)", Base);
 225
 226         // Check magic header
 227
 228
 229         // Parse Program Header to get Dynamic Table
 230         phtab = (void*)( (uintptr_t)Base + hdr->phoff );
 231         iSegmentCount = hdr->phentcount;
 232         for(i=0;i<iSegmentCount;i++)
 233         {
 234                 // Determine linked base address
 235                 if(phtab[i].Type == PT_LOAD && iRealBase > phtab[i].VAddr)
 236                         iRealBase = phtab[i].VAddr;
 237
 238                 // Find Dynamic Section
 239                 if(phtab[i].Type == PT_DYNAMIC) {
 240                         if(dynamicTab) {
 241                                 DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
 242                                 continue;
 243                         }
 244                         dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
 245                         j = i;  // Save Dynamic Table ID
 246                 }
 247         }
 248
 249         // Page Align real base
 250         iRealBase &= ~0xFFF;
 251         DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
 252
 253         // Adjust "Real" Base
 254         iBaseDiff = (intptr_t)Base - iRealBase;
 255
 256 //      hdr->entrypoint += iBaseDiff;   // Adjust Entrypoint
 257
 258         // Check if a PT_DYNAMIC segement was found
 259         if(!dynamicTab) {
 260                 SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 261                 return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
 262         }
 263
 264         // Allow writing to read-only segments, just in case they need to be relocated
 265         // - Will be reversed at the end of the function
 266         for( i = 0; i < iSegmentCount; i ++ )
 267         {
 268                 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
 269                         uintptr_t       addr = phtab[i].VAddr + iBaseDiff;
 270                         uintptr_t       end = addr + phtab[i].MemSize;
 271                         for( ; addr < end; addr += PAGE_SIZE )
 272                                 _SysSetMemFlags(addr, 0, 1);    // Unset RO
 273                 }
 274         }
 275
 276         // Adjust Dynamic Table
 277         dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
 278
 279         // === Get Symbol table and String Table ===
 280         dynsymtab = NULL;
 281         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 282         {
 283                 switch(dynamicTab[j].d_tag)
 284                 {
 285                 // --- Symbol Table ---
 286                 case DT_SYMTAB:
 287                         DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
 288                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 289                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 290                         dynsymtab = (void*)(intptr_t)dynamicTab[j].d_val;
 291                         break;
 292                 // --- String Table ---
 293                 case DT_STRTAB:
 294                         DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
 295                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 296                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 297                         dynstrtab = (void*)(intptr_t)dynamicTab[j].d_val;
 298                         break;
 299                 // --- Hash Table --
 300                 case DT_HASH:
 301                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 302 //                      iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
 303                         break;
 304                 }
 305         }
 306
 307         if(dynsymtab == NULL) {
 308                 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
 309                 return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
 310         }
 311
 312         // === Add to loaded list (can be imported now) ===
 313         AddLoaded( Filename, Base );
 314
 315         // === Parse Relocation Data ===
 316         DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
 317         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 318         {
 319                 switch(dynamicTab[j].d_tag)
 320                 {
 321                 // --- Shared Library Name ---
 322                 case DT_SONAME:
 323                         DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
 324                         break;
 325                 // --- Needed Library ---
 326                 case DT_NEEDED:
 327                         libPath = dynstrtab + dynamicTab[j].d_val;
 328                         DEBUGS(" Required Library '%s'", libPath);
 329                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 330                                 #if DEBUG
 331                                 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
 332                                 #else
 333                                 SysDebug("Unable to load required library '%s'", libPath);
 334                                 #endif
 335                                 return 0;
 336                         }
 337                         DEBUGS(" Lib loaded");
 338                         break;
 339                 // --- PLT/GOT ---
 340 //              case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val);      break;
 341                 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 342                 case DT_PLTREL: pltType = dynamicTab[j].d_val;  break;
 343                 case DT_PLTRELSZ:       pltSz = dynamicTab[j].d_val;    break;
 344
 345                 // --- Relocation ---
 346                 case DT_REL:    rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 347                 case DT_RELSZ:  relSz = dynamicTab[j].d_val;    break;
 348                 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
 349                 case DT_RELA:   rela = (void*)(iBaseDiff + dynamicTab[j].d_val);        break;
 350                 case DT_RELASZ: relaSz = dynamicTab[j].d_val;   break;
 351                 case DT_RELAENT:        relaEntSz = dynamicTab[j].d_val;        break;
 352
 353                 // --- Symbol Table ---
 354                 case DT_SYMTAB:
 355                 // --- Hash Table ---
 356                 case DT_HASH:
 357                 // --- String Table ---
 358                 case DT_STRTAB:
 359                         break;
 360
 361                 // --- Unknown ---
 362                 default:
 363                         if(dynamicTab[j].d_tag > DT_JMPREL)     continue;
 364                         //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
 365                         //      i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
 366                         break;
 367                 }
 368         }
 369
 370         DEBUGS(" elf_relocate: Beginning Relocation");
 371
 372          int    fail = 0;
 373
 374         switch(hdr->machine)
 375         {
 376         case EM_386:
 377                 do_relocate = elf_doRelocate_386;
 378                 break;
 379         case EM_ARM:
 380                 do_relocate = elf_doRelocate_arm;
 381                 break;
 382         default:
 383                 SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
 384                 do_relocate = elf_doRelocate_unk;
 385                 fail = 1;
 386                 break;
 387         }
 388
 389         DEBUGS("do_relocate = %p (%p or %p)", do_relocate, &elf_doRelocate_386, &elf_doRelocate_arm);
 390
 391         #define _doRelocate(r_info, ptr, bRela, addend) \
 392                 do_relocate(r_info, ptr, addend, ELF32_R_TYPE(r_info), bRela, \
 393                         dynstrtab + dynsymtab[ELF32_R_SYM(r_info)].nameOfs, iBaseDiff);
 394
 395         // Parse Relocation Entries
 396         if(rel && relSz)
 397         {
 398                 Elf32_Word      *ptr;
 399                 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
 400                 j = relSz / relEntSz;
 401                 for( i = 0; i < j; i++ )
 402                 {
 403                         //DEBUGS("  Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
 404                         ptr = (void*)(iBaseDiff + rel[i].r_offset);
 405                         fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr);
 406                 }
 407         }
 408         // Parse Relocation Entries
 409         if(rela && relaSz)
 410         {
 411                 Elf32_Word      *ptr;
 412                 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
 413                 j = relaSz / relaEntSz;
 414                 for( i = 0; i < j; i++ )
 415                 {
 416                         ptr = (void*)(iBaseDiff + rela[i].r_offset);
 417                         fail |= _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend);
 418                 }
 419         }
 420
 421         // === Process PLT (Procedure Linkage Table) ===
 422         if(plt && pltSz)
 423         {
 424                 Elf32_Word      *ptr;
 425                 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
 426                 if(pltType == DT_REL)
 427                 {
 428                         Elf32_Rel       *pltRel = plt;
 429                         j = pltSz / sizeof(Elf32_Rel);
 430                         DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", j);
 431                         for(i=0;i<j;i++)
 432                         {
 433                                 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
 434                                 fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr);
 435                         }
 436                 }
 437                 else
 438                 {
 439                         Elf32_Rela      *pltRela = plt;
 440                         j = pltSz / sizeof(Elf32_Rela);
 441                         DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", j);
 442                         for(i=0;i<j;i++)
 443                         {
 444                                 ptr = (void*)(iRealBase + pltRela[i].r_offset);
 445                                 fail |= _doRelocate(pltRela[i].r_info, ptr, 1, pltRela[i].r_addend);
 446                         }
 447                 }
 448         }
 449
 450         // Re-set readonly
 451         for( i = 0; i < iSegmentCount; i ++ )
 452         {
 453                 // If load and not writable
 454                 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
 455                         uintptr_t       addr = phtab[i].VAddr + iBaseDiff;
 456                         uintptr_t       end = addr + phtab[i].MemSize;
 457                         for( ; addr < end; addr += PAGE_SIZE )
 458                                 _SysSetMemFlags(addr, 1, 1);    // Unset RO
 459                 }
 460         }
 461
 462         if( fail ) {
 463                 DEBUGS("ElfRelocate: Failure");
 464                 return NULL;
 465         }
 466
 467         #undef _doRelocate
 468
 469         DEBUGS("ElfRelocate: RETURN 0x%x to %p", hdr->entrypoint + iBaseDiff, __builtin_return_address(0));
 470         return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff );
 471 }
 472
 473 int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
 474 {
 475         Elf32_Ehdr      *hdr = Base;
 476         Elf32_Sym       *symtab = NULL;
 477          int    nbuckets = 0;
 478         Elf32_Word      *pBuckets = NULL;
 479         Elf32_Word      *pChains;
 480         uint32_t        iNameHash;
 481         const char      *dynstrtab = NULL;
 482         uintptr_t       iBaseDiff = -1;
 483         Elf32_Phdr      *phtab;
 484         Elf32_Dyn       *dynTab = NULL;
 485          int    i;
 486
 487         // Locate the tables
 488         phtab = (void*)( (uintptr_t)Base + hdr->phoff );
 489         for( i = 0; i < hdr->phentcount; i ++ )
 490         {
 491                 if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
 492                         iBaseDiff = phtab[i].VAddr;
 493                 if( phtab[i].Type == PT_DYNAMIC ) {
 494                         dynTab = (void*)(intptr_t)phtab[i].VAddr;
 495                 }
 496         }
 497         if( !dynTab ) {
 498                 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 499                 return 0;
 500         }
 501         iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 502         dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 503         for( i = 0; dynTab[i].d_tag != DT_NULL; i++)
 504         {
 505                 switch(dynTab[i].d_tag)
 506                 {
 507                 // --- Symbol Table ---
 508                 case DT_SYMTAB:
 509                         symtab = (void*)(intptr_t) dynTab[i].d_val;     // Rebased in Relocate
 510                         break;
 511                 case DT_STRTAB:
 512                         dynstrtab = (void*)(intptr_t) dynTab[i].d_val;
 513                         break;
 514                 // --- Hash Table --
 515                 case DT_HASH:
 516                         pBuckets = (void*)(intptr_t) dynTab[i].d_val;
 517                         break;
 518                 }
 519         }
 520
 521         if( !symtab ) {
 522                 SysDebug("ERRO - No DT_SYMTAB in %p", Base);
 523                 return 0;
 524         }
 525         if( !pBuckets ) {
 526                 SysDebug("ERRO - No DT_HASH in %p", Base);
 527                 return 0;
 528         }
 529         if( !dynstrtab ) {
 530                 SysDebug("ERRO - No DT_STRTAB in %p", Base);
 531                 return 0;
 532         }
 533
 534         // ... ok... maybe they haven't been relocated
 535         if( (uintptr_t)symtab < (uintptr_t)Base )
 536         {
 537                 symtab    = (void*)( (uintptr_t)symtab    + iBaseDiff );
 538                 pBuckets  = (void*)( (uintptr_t)pBuckets  + iBaseDiff );
 539                 dynstrtab = (void*)( (uintptr_t)dynstrtab + iBaseDiff );
 540                 SysDebug("Executable not yet relocated");
 541         }
 542
 543         nbuckets = pBuckets[0];
 544 //      iSymCount = pBuckets[1];
 545         pBuckets = &pBuckets[2];
 546         pChains = &pBuckets[ nbuckets ];
 547
 548         // Get hash
 549         iNameHash = ElfHashString(Name);
 550         iNameHash %= nbuckets;
 551
 552         // Walk Chain
 553         i = pBuckets[ iNameHash ];
 554         if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
 555                 *ret = (void*)( (uintptr_t) symtab[ i ].value + iBaseDiff );
 556                 if(Size)        *Size = symtab[i].size;
 557                 return 1;
 558         }
 559
 560         while(pChains[i] != STN_UNDEF)
 561         {
 562                 i = pChains[i];
 563                 if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
 564                         *ret = (void*)( (uintptr_t)symtab[ i ].value + iBaseDiff );
 565                         if(Size)        *Size = symtab[i].size;
 566                         return 1;
 567                 }
 568         }
 569
 570         return 0;
 571 }
 572
 573 #ifdef SUPPORT_ELF64
 574 typedef int (*t_elf64_doreloc)(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
 575
 576 int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
 577 {
 578          int    sym = ELF64_R_SYM(r_info);
 579          int    type = ELF64_R_TYPE(r_info);
 580         const char      *symname = strtab + symtab[sym].st_name;
 581         void    *symval;
 582         //DEBUGS("_Elf64DoReloc: %s", symname);
 583         switch( type )
 584         {
 585         case R_X86_64_NONE:
 586                 break;
 587         case R_X86_64_64:
 588                 if( !GetSymbol(symname, &symval, NULL)  )       return 1;
 589                 *(uint64_t*)ptr = (uintptr_t)symval + addend;
 590                 break;
 591         case R_X86_64_COPY: {
 592                 size_t  size;
 593                 if( !GetSymbol(symname, &symval, &size)  )      return 1;
 594                 memcpy(ptr, symval, size);
 595                 } break;
 596         case R_X86_64_GLOB_DAT:
 597                 if( !GetSymbol(symname, &symval, NULL)  )       return 1;
 598                 *(uint64_t*)ptr = (uintptr_t)symval;
 599                 break;
 600         case R_X86_64_JUMP_SLOT:
 601                 if( !GetSymbol(symname, &symval, NULL)  )       return 1;
 602                 *(uint64_t*)ptr = (uintptr_t)symval;
 603                 break;
 604         case R_X86_64_RELATIVE:
 605                 *(uint64_t*)ptr = (uintptr_t)Base + addend;
 606                 break;
 607         default:
 608                 SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
 609                 return 2;
 610         }
 611         //DEBUGS("_Elf64DoReloc: - Good");
 612         return 0;
 613 }
 614
 615 void *Elf64Relocate(void *Base, char **envp, const char *Filename)
 616 {
 617          int    i;
 618         Elf64_Ehdr      *hdr = Base;
 619         Elf64_Phdr      *phtab;
 620         Elf64_Dyn       *dyntab = NULL;
 621         Elf64_Addr      compiledBase = -1, baseDiff;
 622         Elf64_Sym       *symtab = NULL;
 623         char    *strtab = NULL;
 624         Elf64_Word      *hashtab = NULL;
 625         Elf64_Rel       *rel = NULL;
 626          int    rel_count = 0;
 627         Elf64_Rela      *rela = NULL;
 628          int    rela_count = 0;
 629         void    *pltrel = NULL;
 630          int    plt_size = 0, plt_type = 0;
 631
 632         DEBUGS("Elf64Relocate: hdr = {");
 633         DEBUGS("Elf64Relocate:  e_ident = '%.16s'", hdr->e_ident);
 634         DEBUGS("Elf64Relocate:  e_type = 0x%x", hdr->e_type);
 635         DEBUGS("Elf64Relocate:  e_machine = 0x%x", hdr->e_machine);
 636         DEBUGS("Elf64Relocate:  e_version = 0x%x", hdr->e_version);
 637         DEBUGS("Elf64Relocate:  e_entry = %p", hdr->e_entry);
 638         DEBUGS("Elf64Relocate:  e_phoff = 0x%llx", hdr->e_phoff);
 639         DEBUGS("Elf64Relocate:  e_shoff = 0x%llx", hdr->e_shoff);
 640         DEBUGS("Elf64Relocate:  e_flags = 0x%x", hdr->e_flags);
 641         DEBUGS("Elf64Relocate:  e_ehsize = 0x%x", hdr->e_ehsize);
 642         DEBUGS("Elf64Relocate:  e_phentsize = 0x%x", hdr->e_phentsize);
 643         DEBUGS("Elf64Relocate:  e_phnum = %i", hdr->e_phnum);
 644
 645         // Scan for the dynamic table (and find the compiled base)
 646         phtab = (void*)((uintptr_t)Base + (uintptr_t)hdr->e_phoff);
 647         for( i = 0; i < hdr->e_phnum; i ++ )
 648         {
 649                 if(phtab[i].p_type == PT_DYNAMIC)
 650                         dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
 651                 if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
 652                         compiledBase = phtab[i].p_vaddr;
 653         }
 654
 655         baseDiff = (uintptr_t)Base - compiledBase;
 656
 657         DEBUGS("baseDiff = %p", baseDiff);
 658
 659         if(dyntab == NULL) {
 660                 SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 661                 return (void *)(uintptr_t)(hdr->e_entry + baseDiff);
 662         }
 663
 664         dyntab = (void *)(uintptr_t)((uintptr_t)dyntab + baseDiff);
 665
 666         // Parse the dynamic table (first pass)
 667         // - Search for String, Symbol and Hash tables
 668         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 669         {
 670                 switch(dyntab[i].d_tag)
 671                 {
 672                 case DT_SYMTAB:
 673                         dyntab[i].d_un.d_ptr += baseDiff;
 674                         symtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 675                         break;
 676                 case DT_STRTAB:
 677                         dyntab[i].d_un.d_ptr += baseDiff;
 678                         strtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 679                         break;
 680                 case DT_HASH:
 681                         dyntab[i].d_un.d_ptr += baseDiff;
 682                         hashtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 683                         break;
 684                 }
 685         }
 686
 687         if( !symtab || !strtab || !hashtab ) {
 688                 SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
 689                 return NULL;
 690         }
 691
 692         // Ready for symbol use
 693         AddLoaded( Filename, Base );
 694
 695         // Second pass on dynamic table
 696         for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
 697         {
 698                 DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
 699                 switch(dyntab[i].d_tag)
 700                 {
 701                 case DT_SONAME: break;
 702
 703                 case DT_NEEDED: {
 704                         char *libPath = strtab + dyntab[i].d_un.d_val;
 705                         DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
 706                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 707                                 SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
 708                                 return NULL;
 709                         }
 710                         } break;
 711
 712                 // Relocation entries
 713                 case DT_REL:
 714                         dyntab[i].d_un.d_ptr += baseDiff;
 715                         rel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 716                         break;
 717                 case DT_RELSZ:
 718                         rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
 719                         break;
 720                 case DT_RELENT:
 721                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
 722                                 SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
 723                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
 724                                 return NULL;
 725                         }
 726                         break;
 727                 case DT_RELA:
 728                         dyntab[i].d_un.d_ptr += baseDiff;
 729                         rela = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 730                         break;
 731                 case DT_RELASZ:
 732                         rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
 733                         break;
 734                 case DT_RELAENT:
 735                         if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
 736                                 SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
 737                                         dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
 738                                 return NULL;
 739                         }
 740                         break;
 741                 case DT_JMPREL:
 742                         dyntab[i].d_un.d_ptr += baseDiff;
 743                         pltrel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
 744                         break;
 745                 case DT_PLTREL:
 746                         plt_type = dyntab[i].d_un.d_val;
 747                         break;
 748                 case DT_PLTRELSZ:
 749                         plt_size = dyntab[i].d_un.d_val;
 750                         break;
 751                 }
 752         }
 753
 754         // Relocation function
 755         t_elf64_doreloc fpElf64DoReloc = &_Elf64DoReloc_X86_64;
 756         #define _Elf64DoReloc(info, ptr, addend)        fpElf64DoReloc(Base, strtab, symtab, info, ptr, addend)
 757
 758         int fail = 0;
 759         if( rel )
 760         {
 761                 DEBUGS("rel_count = %i", rel_count);
 762                 for( i = 0; i < rel_count; i ++ )
 763                 {
 764                         uint64_t *ptr = (void *)(uintptr_t)( rel[i].r_offset + baseDiff );
 765                         fail |= _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
 766                 }
 767         }
 768
 769         if( rela )
 770         {
 771                 DEBUGS("rela_count = %i", rela_count);
 772                 for( i = 0; i < rela_count; i ++ )
 773                 {
 774                         uint64_t *ptr = (void *)(uintptr_t)( rela[i].r_offset + baseDiff );
 775                         fail |= _Elf64DoReloc( rela[i].r_info, ptr, rela[i].r_addend );
 776                 }
 777         }
 778
 779         if( pltrel && plt_type )
 780         {
 781                 if( plt_type == DT_REL ) {
 782                         Elf64_Rel       *plt = pltrel;
 783                          int    count = plt_size / sizeof(Elf64_Rel);
 784                         DEBUGS("plt rel count = %i", count);
 785                         for( i = 0; i < count; i ++ )
 786                         {
 787                                 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
 788                                 fail |= _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
 789                         }
 790                 }
 791                 else {
 792                         Elf64_Rela      *plt = pltrel;
 793                          int    count = plt_size / sizeof(Elf64_Rela);
 794                         DEBUGS("plt rela count = %i", count);
 795                         for( i = 0; i < count; i ++ )
 796                         {
 797                                 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
 798                                 fail |= _Elf64DoReloc( plt[i].r_info, ptr, plt[i].r_addend);
 799                         }
 800                 }
 801         }
 802
 803         if( fail ) {
 804                 DEBUGS("Elf64Relocate: Failure");
 805                 return NULL;
 806         }
 807
 808         {
 809         void *ret = (void *)(uintptr_t)(hdr->e_entry + baseDiff);
 810         DEBUGS("Elf64Relocate: Relocations done, return %p", ret);
 811         return ret;
 812         }
 813 }
 814
 815 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size)
 816 {
 817         Elf64_Ehdr      *hdr = Base;
 818         Elf64_Sym       *symtab;
 819          int    nbuckets = 0;
 820 //       int    iSymCount = 0;
 821          int    i;
 822         Elf64_Word      *pBuckets;
 823         Elf64_Word      *pChains;
 824         uint32_t        iNameHash;
 825         const char      *dynstrtab;
 826         uintptr_t       iBaseDiff = -1;
 827
 828         dynstrtab = NULL;
 829         pBuckets = NULL;
 830         symtab = NULL;
 831
 832         // Catch the current executable
 833         if( !pBuckets )
 834         {
 835                 Elf64_Phdr      *phtab;
 836                 Elf64_Dyn       *dynTab = NULL;
 837                  int    j;
 838
 839                 // Locate the tables
 840                 phtab = (void*)( (intptr_t)Base + (uintptr_t)hdr->e_phoff );
 841                 for( i = 0; i < hdr->e_phnum; i ++ )
 842                 {
 843                         if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
 844                                 iBaseDiff = phtab[i].p_vaddr;
 845                         if( phtab[i].p_type == PT_DYNAMIC ) {
 846                                 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
 847                         }
 848                 }
 849                 if( !dynTab ) {
 850                         SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 851                         return 0;
 852                 }
 853                 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 854                 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 855
 856                 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
 857                 {
 858                         switch(dynTab[j].d_tag)
 859                         {
 860                         // --- Symbol Table ---
 861                         case DT_SYMTAB:
 862                                 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val;        // Rebased in Relocate
 863                                 break;
 864                         case DT_STRTAB:
 865                                 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
 866                                 break;
 867                         // --- Hash Table --
 868                         case DT_HASH:
 869                                 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
 870                                 break;
 871                         }
 872                 }
 873         }
 874
 875         nbuckets = pBuckets[0];
 876 //      iSymCount = pBuckets[1];
 877         pBuckets = &pBuckets[2];
 878         pChains = &pBuckets[ nbuckets ];
 879
 880         // Get hash
 881         iNameHash = ElfHashString(Name);
 882         iNameHash %= nbuckets;
 883
 884         // Walk Chain
 885         i = pBuckets[ iNameHash ];
 886         if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 887                 *Ret = (void*)( (intptr_t)symtab[i].st_value + iBaseDiff );
 888                 if(Size)        *Size = symtab[i].st_size;
 889                 DEBUGS("%s = %p", Name, *Ret);
 890                 return 1;
 891         }
 892
 893         while(pChains[i] != STN_UNDEF)
 894         {
 895                 i = pChains[i];
 896                 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 897                         *Ret = (void*)((intptr_t)symtab[i].st_value + iBaseDiff);
 898                         if(Size)        *Size = symtab[i].st_size;
 899                         DEBUGS("%s = %p", Name, *Ret);
 900                         return 1;
 901                 }
 902         }
 903
 904         return 0;
 905 }
 906 #endif
 907
 908
 909 uint32_t ElfHashString(const char *name)
 910 {
 911         uint32_t        h = 0, g;
 912         while(*name)
 913         {
 914                 h = (h << 4) + *(uint8_t*)name++;
 915                 if( (g = h & 0xf0000000) )
 916                         h ^= g >> 24;
 917                 h &= ~g;
 918         }
 919         return h;
 920 }
 921