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

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