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_GLOB_DAT:
 207                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname);
 208                         break;
 209                 case R_X86_64_JUMP_SLOT:
 210                         *(uint64_t*)ptr = (uint64_t)GetSymbol(symname);
 211                         break;
 212                 default:
 213                         SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
 214                         break;
 215                 }
 216         }
 217
 218         if( rel )
 219         {
 220                 DEBUGS("rel_count = %i", rel_count);
 221                 for( i = 0; i < rel_count; i ++ )
 222                 {
 223                         uint64_t *ptr = (void *)( rel[i].r_offset + baseDiff );
 224                         _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
 225                 }
 226         }
 227
 228         if( rela )
 229         {
 230                 DEBUGS("rela_count = %i", rela_count);
 231                 for( i = 0; i < rela_count; i ++ )
 232                 {
 233                         _Elf64DoReloc( rela[i].r_info, (void *)( rela[i].r_offset + baseDiff ), rela[i].r_addend );
 234                 }
 235         }
 236
 237         if( pltrel && plt_type )
 238         {
 239                 if( plt_type == DT_REL ) {
 240                         Elf64_Rel       *plt = pltrel;
 241                          int    count = plt_size / sizeof(Elf64_Rel);
 242                         DEBUGS("plt rel count = %i", count);
 243                         for( i = 0; i < count; i ++ )
 244                         {
 245                                 uint64_t *ptr = (void *)( plt[i].r_offset + baseDiff );
 246                                 _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
 247                         }
 248                 }
 249                 else {
 250                         Elf64_Rela      *plt = pltrel;
 251                          int    count = plt_size / sizeof(Elf64_Rela);
 252                         DEBUGS("plt rela count = %i", count);
 253                         for( i = 0; i < count; i ++ )
 254                         {
 255                                 _Elf64DoReloc( plt[i].r_info, (void *)(plt[i].r_offset + baseDiff), plt[i].r_addend);
 256                         }
 257                 }
 258         }
 259
 260         DEBUGS("Elf64Relocate: Relocations done, return %p", (void *)(hdr->e_entry + baseDiff));
 261         return (void *)(hdr->e_entry + baseDiff);
 262 }
 263
 264 void *Elf32Relocate(void *Base, char **envp, const char *Filename)
 265 {
 266         Elf32_Ehdr      *hdr = Base;
 267         Elf32_Phdr      *phtab;
 268          int    i, j;   // Counters
 269         char    *libPath;
 270         intptr_t        iRealBase = -1;
 271         intptr_t        iBaseDiff;
 272          int    iSegmentCount;
 273          int    iSymCount;
 274         Elf32_Rel       *rel = NULL;
 275         Elf32_Rela      *rela = NULL;
 276         Uint32  *pltgot = NULL;
 277         void    *plt = NULL;
 278          int    relSz=0, relEntSz=8;
 279          int    relaSz=0, relaEntSz=8;
 280          int    pltSz=0, pltType=0;
 281         Elf32_Dyn       *dynamicTab = NULL;     // Dynamic Table Pointer
 282         char    *dynstrtab = NULL;      // .dynamic String Table
 283         Elf32_Sym       *dynsymtab;
 284
 285         DEBUGS("ElfRelocate: (Base=0x%x)", Base);
 286
 287         // Check magic header
 288
 289
 290         // Parse Program Header to get Dynamic Table
 291         phtab = Base + hdr->phoff;
 292         iSegmentCount = hdr->phentcount;
 293         for(i=0;i<iSegmentCount;i++)
 294         {
 295                 // Determine linked base address
 296                 if(phtab[i].Type == PT_LOAD && iRealBase > phtab[i].VAddr)
 297                         iRealBase = phtab[i].VAddr;
 298
 299                 // Find Dynamic Section
 300                 if(phtab[i].Type == PT_DYNAMIC) {
 301                         if(dynamicTab) {
 302                                 DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
 303                                 continue;
 304                         }
 305                         dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
 306                         j = i;  // Save Dynamic Table ID
 307                 }
 308         }
 309
 310         // Page Align real base
 311         iRealBase &= ~0xFFF;
 312         DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
 313
 314         // Adjust "Real" Base
 315         iBaseDiff = (intptr_t)Base - iRealBase;
 316
 317 //      hdr->entrypoint += iBaseDiff;   // Adjust Entrypoint
 318
 319         // Check if a PT_DYNAMIC segement was found
 320         if(!dynamicTab) {
 321                 SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
 322                 return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
 323         }
 324
 325         // Adjust Dynamic Table
 326         dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
 327
 328         // === Get Symbol table and String Table ===
 329         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 330         {
 331                 switch(dynamicTab[j].d_tag)
 332                 {
 333                 // --- Symbol Table ---
 334                 case DT_SYMTAB:
 335                         DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
 336                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 337                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 338                         dynsymtab = (void*)(dynamicTab[j].d_val);
 339 //                      hdr->misc.SymTable = dynamicTab[j].d_val;       // Saved in unused bytes of ident
 340                         break;
 341                 // --- String Table ---
 342                 case DT_STRTAB:
 343                         DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
 344                                 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
 345                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 346                         dynstrtab = (void*)(dynamicTab[j].d_val);
 347                         break;
 348                 // --- Hash Table --
 349                 case DT_HASH:
 350                         if(iBaseDiff != 0)      dynamicTab[j].d_val += iBaseDiff;
 351                         iSymCount = ((Elf32_Word*)(dynamicTab[j].d_val))[1];
 352 //                      hdr->misc.HashTable = dynamicTab[j].d_val;      // Saved in unused bytes of ident
 353                         break;
 354                 }
 355         }
 356
 357         if(dynsymtab == NULL) {
 358                 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
 359                 return (void *) hdr->entrypoint + iBaseDiff;
 360         }
 361
 362         #if 0
 363         // Alter Symbols to true base
 364         for(i=0;i<iSymCount;i++)
 365         {
 366                 dynsymtab[i].value += iBaseDiff;
 367                 dynsymtab[i].nameOfs += (intptr_t)dynstrtab;
 368                 //DEBUGS("elf_relocate: Sym '%s' = 0x%x (relocated)", dynsymtab[i].name, dynsymtab[i].value);
 369         }
 370         #endif
 371
 372         // === Add to loaded list (can be imported now) ===
 373         AddLoaded( Filename, Base );
 374
 375         // === Parse Relocation Data ===
 376         DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
 377         for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
 378         {
 379                 switch(dynamicTab[j].d_tag)
 380                 {
 381                 // --- Shared Library Name ---
 382                 case DT_SONAME:
 383                         DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
 384                         break;
 385                 // --- Needed Library ---
 386                 case DT_NEEDED:
 387                         libPath = dynstrtab + dynamicTab[j].d_val;
 388                         DEBUGS(" Required Library '%s'", libPath);
 389                         if(LoadLibrary(libPath, NULL, envp) == 0) {
 390                                 #if DEBUG
 391                                 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
 392                                 #else
 393                                 SysDebug("Unable to load required library '%s'", libPath);
 394                                 #endif
 395                                 return 0;
 396                         }
 397                         break;
 398                 // --- PLT/GOT ---
 399                 case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val);      break;
 400                 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 401                 case DT_PLTREL: pltType = dynamicTab[j].d_val;  break;
 402                 case DT_PLTRELSZ:       pltSz = dynamicTab[j].d_val;    break;
 403
 404                 // --- Relocation ---
 405                 case DT_REL:    rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
 406                 case DT_RELSZ:  relSz = dynamicTab[j].d_val;    break;
 407                 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
 408                 case DT_RELA:   rela = (void*)(iBaseDiff + dynamicTab[j].d_val);        break;
 409                 case DT_RELASZ: relaSz = dynamicTab[j].d_val;   break;
 410                 case DT_RELAENT:        relaEntSz = dynamicTab[j].d_val;        break;
 411
 412                 // --- Symbol Table ---
 413                 case DT_SYMTAB:
 414                 // --- Hash Table ---
 415                 case DT_HASH:
 416                 // --- String Table ---
 417                 case DT_STRTAB:
 418                         break;
 419
 420                 // --- Unknown ---
 421                 default:
 422                         if(dynamicTab[j].d_tag > DT_JMPREL)     continue;
 423                         //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
 424                         //      i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
 425                         break;
 426                 }
 427         }
 428
 429         DEBUGS(" elf_relocate: Beginning Relocation");
 430
 431         void elf_doRelocate(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, Elf32_Sym *symtab)
 432         {
 433                  int    type = ELF32_R_TYPE(r_info);
 434                  int    sym = ELF32_R_SYM(r_info);
 435                 Uint32  val;
 436                 const char      *symname = dynstrtab + symtab[sym].nameOfs;
 437                 switch( type )
 438                 {
 439                 // Standard 32 Bit Relocation (S+A)
 440                 case R_386_32:
 441                         val = (intptr_t) GetSymbol( symname );
 442                         DEBUGS(" elf_doRelocate: R_386_32 *0x%x += 0x%x('%s')",
 443                                         ptr, val, symname);
 444                         *ptr = val + addend;
 445                         break;
 446
 447                 // 32 Bit Relocation wrt. Offset (S+A-P)
 448                 case R_386_PC32:
 449                         DEBUGS(" elf_doRelocate: #%i: '%s'", sym, symname);
 450                         val = (intptr_t) GetSymbol( symname );
 451                         DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%x - 0x%x",
 452                                 ptr, *ptr, val, (intptr_t)ptr );
 453                         *ptr = val + addend - (intptr_t)ptr;
 454                         //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
 455                         break;
 456
 457                 // Absolute Value of a symbol (S)
 458                 case R_386_GLOB_DAT:
 459                 case R_386_JMP_SLOT:
 460                         DEBUGS(" elf_doRelocate: #%i: '%s'", sym, symname);
 461                         val = (intptr_t) GetSymbol( symname );
 462                         DEBUGS(" elf_doRelocate: %s *0x%x = 0x%x", csaR_NAMES[type], ptr, val);
 463                         *ptr = val;
 464                         break;
 465
 466                 // Base Address (B+A)
 467                 case R_386_RELATIVE:
 468                         DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
 469                         *ptr = iBaseDiff + addend;
 470                         break;
 471
 472                 default:
 473                         DEBUGS(" elf_doRelocate: Rel 0x%x: 0x%x,%s", ptr, sym, csaR_NAMES[type]);
 474                         break;
 475                 }
 476         }
 477
 478         // Parse Relocation Entries
 479         if(rel && relSz)
 480         {
 481                 Uint32  *ptr;
 482                 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
 483                 j = relSz / relEntSz;
 484                 for( i = 0; i < j; i++ )
 485                 {
 486                         //DEBUGS("  Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
 487                         ptr = (void*)(iBaseDiff + rel[i].r_offset);
 488                         elf_doRelocate(rel[i].r_info, ptr, *ptr, dynsymtab);
 489                 }
 490         }
 491         // Parse Relocation Entries
 492         if(rela && relaSz)
 493         {
 494                 Uint32  *ptr;
 495                 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
 496                 j = relaSz / relaEntSz;
 497                 for( i = 0; i < j; i++ )
 498                 {
 499                         ptr = (void*)(iBaseDiff + rela[i].r_offset);
 500                         elf_doRelocate(rel[i].r_info, ptr, rela[i].r_addend, dynsymtab);
 501                 }
 502         }
 503
 504         // === Process PLT (Procedure Linkage Table) ===
 505         if(plt && pltSz)
 506         {
 507                 Uint32  *ptr;
 508                 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
 509                 if(pltType == DT_REL)
 510                 {
 511                         Elf32_Rel       *pltRel = plt;
 512                         j = pltSz / sizeof(Elf32_Rel);
 513                         DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", j);
 514                         for(i=0;i<j;i++)
 515                         {
 516                                 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
 517                                 elf_doRelocate(pltRel[i].r_info, ptr, *ptr, dynsymtab);
 518                         }
 519                 }
 520                 else
 521                 {
 522                         Elf32_Rela      *pltRela = plt;
 523                         j = pltSz / sizeof(Elf32_Rela);
 524                         DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", j);
 525                         for(i=0;i<j;i++)
 526                         {
 527                                 ptr = (void*)(iRealBase + pltRela[i].r_offset);
 528                                 elf_doRelocate(pltRela[i].r_info, ptr, pltRela[i].r_addend, dynsymtab);
 529                         }
 530                 }
 531         }
 532
 533         DEBUGS("ElfRelocate: RETURN 0x%x", hdr->entrypoint + iBaseDiff);
 534         return (void*)hdr->entrypoint + iBaseDiff;
 535 }
 536
 537
 538 /**
 539  * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
 540  */
 541 int ElfGetSymbol(void *Base, const char *Name, void **ret)
 542 {
 543         Elf32_Ehdr      *hdr = Base;
 544
 545         switch(hdr->e_ident[4])
 546         {
 547         case ELFCLASS32:
 548                 return Elf32GetSymbol(Base, Name, ret);
 549         case ELFCLASS64:
 550                 return Elf64GetSymbol(Base, Name, ret);
 551         default:
 552                 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
 553                 return 0;
 554         }
 555 }
 556
 557 int Elf64GetSymbol(void *Base, const char *Name, void **Ret)
 558 {
 559         Elf64_Ehdr      *hdr = Base;
 560         Elf64_Sym       *symtab;
 561          int    nbuckets = 0;
 562          int    iSymCount = 0;
 563          int    i;
 564         Elf64_Word      *pBuckets;
 565         Elf64_Word      *pChains;
 566         uint32_t        iNameHash;
 567         const char      *dynstrtab;
 568         uintptr_t       iBaseDiff = -1;
 569
 570 //      DEBUGS("sizeof(uint32_t) = %i, sizeof(Elf64_Word) = %i", sizeof(uint32_t), sizeof(Elf64_Word));
 571
 572         dynstrtab = NULL;
 573         pBuckets = NULL;
 574         symtab = NULL;
 575
 576         // Catch the current executable
 577         if( !pBuckets )
 578         {
 579                 Elf64_Phdr      *phtab;
 580                 Elf64_Dyn       *dynTab = NULL;
 581                  int    j;
 582
 583                 // Locate the tables
 584                 phtab = (void*)( Base + hdr->e_phoff );
 585                 for( i = 0; i < hdr->e_phnum; i ++ )
 586                 {
 587                         if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
 588                                 iBaseDiff = phtab[i].p_vaddr;
 589                         if( phtab[i].p_type == PT_DYNAMIC ) {
 590                                 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
 591                         }
 592                 }
 593                 if( !dynTab ) {
 594                         SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 595                         return 0;
 596                 }
 597                 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 598                 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 599
 600                 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
 601                 {
 602                         switch(dynTab[j].d_tag)
 603                         {
 604                         // --- Symbol Table ---
 605                         case DT_SYMTAB:
 606                                 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val;        // Rebased in Relocate
 607                                 break;
 608                         case DT_STRTAB:
 609                                 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
 610                                 break;
 611                         // --- Hash Table --
 612                         case DT_HASH:
 613                                 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
 614                                 break;
 615                         }
 616                 }
 617         }
 618 //      DEBUGS("pBuckets = %p", pBuckets);
 619
 620         nbuckets = pBuckets[0];
 621         iSymCount = pBuckets[1];
 622         pBuckets = &pBuckets[2];
 623 //      DEBUGS("nbuckets = %i", nbuckets);
 624         pChains = &pBuckets[ nbuckets ];
 625
 626         // Get hash
 627         iNameHash = ElfHashString(Name);
 628         iNameHash %= nbuckets;
 629
 630         // Walk Chain
 631         i = pBuckets[ iNameHash ];
 632 //      DEBUGS("dynstrtab = %p", dynstrtab);
 633 //      DEBUGS("symtab = %p, i = %i", symtab, i);
 634         if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 635                 *Ret = (void*) (intptr_t) symtab[i].st_value + iBaseDiff;
 636                 DEBUGS("%s = %p", Name, *Ret);
 637                 return 1;
 638         }
 639
 640         while(pChains[i] != STN_UNDEF)
 641         {
 642                 i = pChains[i];
 643 //              DEBUGS("chains i = %i", i);
 644                 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
 645                         *Ret = (void*)(intptr_t)symtab[i].st_value + iBaseDiff;
 646                         DEBUGS("%s = %p", Name, *Ret);
 647                         return 1;
 648                 }
 649         }
 650
 651 //      DEBUGS("Elf64GetSymbol: RETURN 0, Symbol '%s' not found", Name);
 652         return 0;
 653 }
 654
 655 int Elf32GetSymbol(void *Base, const char *Name, void **ret)
 656 {
 657         Elf32_Ehdr      *hdr = Base;
 658         Elf32_Sym       *symtab;
 659          int    nbuckets = 0;
 660          int    iSymCount = 0;
 661          int    i;
 662         Uint32  *pBuckets;
 663         Uint32  *pChains;
 664         uint32_t        iNameHash;
 665         const char      *dynstrtab;
 666         uintptr_t       iBaseDiff = -1;
 667
 668         //DEBUGS("ElfGetSymbol: (Base=0x%x, Name='%s')", Base, Name);
 669         dynstrtab = NULL;
 670         pBuckets = NULL;
 671         symtab = NULL;
 672
 673         // Catch the current executable
 674         if( !pBuckets )
 675         {
 676                 Elf32_Phdr      *phtab;
 677                 Elf32_Dyn       *dynTab = NULL;
 678                  int    j;
 679
 680                 // Locate the tables
 681                 phtab = (void*)( Base + hdr->phoff );
 682                 for( i = 0; i < hdr->phentcount; i ++ )
 683                 {
 684                         if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
 685                                 iBaseDiff = phtab[i].VAddr;
 686                         if( phtab[i].Type == PT_DYNAMIC ) {
 687                                 dynTab = (void*)(intptr_t)phtab[i].VAddr;
 688                         }
 689                 }
 690                 if( !dynTab ) {
 691                         SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
 692                         return 0;
 693                 }
 694                 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
 695                 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
 696
 697                 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
 698                 {
 699                         switch(dynTab[j].d_tag)
 700                         {
 701                         // --- Symbol Table ---
 702                         case DT_SYMTAB:
 703                                 symtab = (void*)(intptr_t) dynTab[j].d_val;     // Rebased in Relocate
 704                                 break;
 705                         case DT_STRTAB:
 706                                 dynstrtab = (void*)(intptr_t) dynTab[j].d_val;
 707                                 break;
 708                         // --- Hash Table --
 709                         case DT_HASH:
 710                                 pBuckets = (void*)(intptr_t) dynTab[j].d_val;
 711                                 break;
 712                         }
 713                 }
 714
 715                 #if 0
 716                 hdr->misc.HashTable = pBuckets;
 717                 hdr->misc.SymTable = symtab;
 718                 hdr->misc.StrTab = dynstrtab;
 719                 #endif
 720         }
 721
 722         nbuckets = pBuckets[0];
 723         iSymCount = pBuckets[1];
 724         pBuckets = &pBuckets[2];
 725         pChains = &pBuckets[ nbuckets ];
 726
 727         // Get hash
 728         iNameHash = ElfHashString(Name);
 729         iNameHash %= nbuckets;
 730         //DEBUGS(" ElfGetSymbol: iNameHash = 0x%x", iNameHash);
 731
 732         // Walk Chain
 733         i = pBuckets[ iNameHash ];
 734         //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")", symtab[i].name);
 735         if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
 736                 *ret = (void*) (intptr_t) symtab[ i ].value + iBaseDiff;
 737                 return 1;
 738         }
 739
 740         //DEBUGS(" ElfGetSymbol: Hash of first = 0x%x", ElfHashString( symtab[i].name ) % nbuckets);
 741         while(pChains[i] != STN_UNDEF)
 742         {
 743                 //DEBUGS(" pChains[%i] = %i", i, pChains[i]);
 744                 i = pChains[i];
 745                 //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")", symtab[ i ].name);
 746                 if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
 747                         //DEBUGS("ElfGetSymbol: RETURN 1, '%s' = 0x%x", symtab[ i ].name, symtab[ i ].value);
 748                         *ret = (void*)(intptr_t)symtab[ i ].value + iBaseDiff;
 749                         return 1;
 750                 }
 751         }
 752
 753         //DEBUGS("ElfGetSymbol: RETURN 0, Symbol '%s' not found", Name);
 754         return 0;
 755 }
 756
 757 Uint32 ElfHashString(const char *name)
 758 {
 759         Uint32  h = 0, g;
 760         while(*name)
 761         {
 762                 h = (h << 4) + *(Uint8*)name++;
 763                 if( (g = h & 0xf0000000) )
 764                         h ^= g >> 24;
 765                 h &= ~g;
 766         }
 767         return h;
 768 }
 769
 770 #if 0
 771 unsigned long elf_hash(const unsigned char *name)
 772 {
 773         unsigned long   h = 0, g;
 774         while (*name)
 775         {
 776                 h = (h << 4) + *name++;
 777                 if (g = h & 0xf0000000)
 778                         h ^= g >> 24;
 779                 h &= ~g;
 780         }
 781         return h;
 782 }
 783 #endif