2 * Acess2 Dynamic Linker
3 * - By John Hodge (thePowersGang)
6 * - ELF32/ELF64 relocation
8 #ifndef DEBUG // This code is #include'd from the kernel, so DEBUG may already be defined
13 # define PAGE_SIZE 4096
22 # define DEBUGS(v...) SysDebug("ld-acess - " v)
28 # define SUPPORT_ELF64
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"};
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);
46 int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
47 void *Elf64Relocate(void *Base, char **envp, const char *Filename);
48 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
50 uint32_t ElfHashString(const char *name);
54 * \fn int ElfRelocate(void *Base, char **envp, const char *Filename)
55 * \brief Relocates a loaded ELF Executable
57 void *ElfRelocate(void *Base, char **envp, const char *Filename)
59 Elf32_Ehdr *hdr = Base;
61 switch(hdr->e_ident[4])
64 return Elf32Relocate(Base, envp, Filename);
67 return Elf64Relocate(Base, envp, Filename);
70 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
76 * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
78 int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
80 Elf32_Ehdr *hdr = Base;
82 switch(hdr->e_ident[4])
85 return Elf32GetSymbol(Base, Name, ret, Size);
88 return Elf64GetSymbol(Base, Name, ret, Size);
91 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
96 int elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type,
97 int bRela, const char *Sym, intptr_t iBaseDiff)
102 // Standard 32 Bit Relocation (S+A)
104 if( !GetSymbol(Sym, &symval, NULL) )
106 DEBUGS(" elf_doRelocate: R_386_32 *0x%x += %p('%s')",
108 *ptr = (intptr_t)symval + addend;
111 // 32 Bit Relocation wrt. Offset (S+A-P)
113 DEBUGS(" elf_doRelocate: '%s'", Sym);
114 if( !GetSymbol(Sym, &symval, NULL) ) return 1;
115 DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%p - 0x%x",
116 ptr, *ptr, symval, (intptr_t)ptr );
117 *ptr = (intptr_t)symval + addend - (intptr_t)ptr;
118 //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
121 // Absolute Value of a symbol (S)
124 DEBUGS(" elf_doRelocate: '%s'", Sym);
125 if( !GetSymbol(Sym, &symval, NULL) ) return 1;
126 DEBUGS(" elf_doRelocate: %s *0x%x = %p", csaR_NAMES[type], ptr, symval);
127 *ptr = (intptr_t)symval;
130 // Base Address (B+A)
132 DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
133 *ptr = iBaseDiff + addend;
138 if( !GetSymbol(Sym, &symval, &size) ) return 1;
139 DEBUGS(" elf_doRelocate_386: R_386_COPY (%p, %p, %i)", ptr, symval, size);
140 memcpy(ptr, symval, size);
144 SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
150 int elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
157 DEBUGS(" elf_doRelocate_arm: R_ARM_ABS32 %p (%s + %x)", ptr, Sym, addend);
158 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
162 DEBUGS(" elf_doRelocate_arm: R_ARM_GLOB_DAT %p (%s + %x)", ptr, Sym, addend);
163 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
166 case R_ARM_JUMP_SLOT:
167 if(!bRela) addend = 0;
168 DEBUGS(" elf_doRelocate_arm: R_ARM_JUMP_SLOT %p (%s + %x)", ptr, Sym, addend);
169 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
176 if( !GetSymbol(Sym, &src, &size) ) return 1;
177 DEBUGS(" elf_doRelocate_arm: R_ARM_COPY (%p, %p, %i)", ptr, src, size);
178 memcpy(ptr, src, size);
180 // Delta between link and runtime locations + A
182 DEBUGS(" elf_doRelocate_arm: R_ARM_RELATIVE %p (0x%x + 0x%x)", ptr, iBaseDiff, addend);
184 // TODO: Get delta for a symbol
185 SysDebug("elf_doRelocate_arm: TODO - Implment R_ARM_RELATIVE for symbols");
189 *ptr = iBaseDiff + addend;
193 SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
199 int elf_doRelocate_unk(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
204 void *Elf32Relocate(void *Base, char **envp, const char *Filename)
206 Elf32_Ehdr *hdr = Base;
209 intptr_t iRealBase = -1;
212 Elf32_Rel *rel = NULL;
213 Elf32_Rela *rela = NULL;
215 int relSz=0, relEntSz=8;
216 int relaSz=0, relaEntSz=8;
217 int pltSz=0, pltType=0;
218 Elf32_Dyn *dynamicTab = NULL; // Dynamic Table Pointer
219 char *dynstrtab = NULL; // .dynamic String Table
220 Elf32_Sym *dynsymtab;
221 int (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, int bRela, const char *Sym, intptr_t iBaseDiff);
223 DEBUGS("ElfRelocate: (Base=0x%x)", Base);
225 // Check magic header
228 // Parse Program Header to get Dynamic Table
229 phtab = (void*)( (uintptr_t)Base + hdr->phoff );
230 iSegmentCount = hdr->phentcount;
231 for(int i = 0; i < iSegmentCount; i ++)
233 switch(phtab[i].Type)
236 // Determine linked base address
237 if( iRealBase > phtab[i].VAddr)
238 iRealBase = phtab[i].VAddr;
241 // Find Dynamic Section
243 dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
246 DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
252 // Page Align real base
254 DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
256 // Adjust "Real" Base
257 iBaseDiff = (intptr_t)Base - iRealBase;
259 // hdr->entrypoint += iBaseDiff; // Adjust Entrypoint
261 // Check if a PT_DYNAMIC segement was found
263 SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
264 return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
267 // Allow writing to read-only segments, just in case they need to be relocated
268 // - Will be reversed at the end of the function
269 for( int i = 0; i < iSegmentCount; i ++ )
271 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
272 uintptr_t addr = phtab[i].VAddr + iBaseDiff;
273 uintptr_t end = addr + phtab[i].MemSize;
274 for( ; addr < end; addr += PAGE_SIZE )
275 _SysSetMemFlags(addr, 0, 1); // Unset RO
279 // Adjust Dynamic Table
280 dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
282 // === Get Symbol table and String Table ===
284 for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
286 switch(dynamicTab[j].d_tag)
288 // --- Symbol Table ---
290 DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
291 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
292 dynsymtab = (void*)((intptr_t)dynamicTab[j].d_val + iBaseDiff);
293 //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
295 // --- String Table ---
297 DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
298 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
299 dynstrtab = (void*)((intptr_t)dynamicTab[j].d_val + iBaseDiff);
300 //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
304 //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
305 // iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
310 if(dynsymtab == NULL) {
311 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
312 return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
315 // === Add to loaded list (can be imported now) ===
316 AddLoaded( Filename, Base );
318 // === Parse Relocation Data ===
319 DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
320 for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
322 switch(dynamicTab[j].d_tag)
324 // --- Shared Library Name ---
326 DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
328 // --- Needed Library ---
330 libPath = dynstrtab + dynamicTab[j].d_val;
331 DEBUGS(" dynstrtab = %p, d_val = 0x%x", dynstrtab, dynamicTab[j].d_val);
332 DEBUGS(" Required Library '%s'", libPath);
333 if(LoadLibrary(libPath, NULL, envp) == 0) {
335 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
337 SysDebug("Unable to load required library '%s'", libPath);
341 DEBUGS(" Lib loaded");
344 // case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
345 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
346 case DT_PLTREL: pltType = dynamicTab[j].d_val; break;
347 case DT_PLTRELSZ: pltSz = dynamicTab[j].d_val; break;
349 // --- Relocation ---
350 case DT_REL: rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
351 case DT_RELSZ: relSz = dynamicTab[j].d_val; break;
352 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
353 case DT_RELA: rela = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
354 case DT_RELASZ: relaSz = dynamicTab[j].d_val; break;
355 case DT_RELAENT: relaEntSz = dynamicTab[j].d_val; break;
357 // --- Symbol Table ---
359 // --- Hash Table ---
361 // --- String Table ---
367 if(dynamicTab[j].d_tag > DT_JMPREL) continue;
368 //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
369 // i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
374 DEBUGS(" elf_relocate: Beginning Relocation");
381 do_relocate = elf_doRelocate_386;
384 do_relocate = elf_doRelocate_arm;
387 SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
388 do_relocate = elf_doRelocate_unk;
393 DEBUGS("do_relocate = %p (%p or %p)", do_relocate, &elf_doRelocate_386, &elf_doRelocate_arm);
395 #define _doRelocate(r_info, ptr, bRela, addend) \
396 do_relocate(r_info, ptr, addend, ELF32_R_TYPE(r_info), bRela, \
397 dynstrtab + dynsymtab[ELF32_R_SYM(r_info)].nameOfs, iBaseDiff);
399 // Parse Relocation Entries
403 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
404 int max = relSz / relEntSz;
405 for( int i = 0; i < max; i++ )
407 //DEBUGS(" Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
408 ptr = (void*)(iBaseDiff + rel[i].r_offset);
409 fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr);
412 // Parse Relocation Entries
416 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
417 int count = relaSz / relaEntSz;
418 for( int i = 0; i < count; i++ )
420 ptr = (void*)(iBaseDiff + rela[i].r_offset);
421 fail |= _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend);
425 // === Process PLT (Procedure Linkage Table) ===
429 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
430 if(pltType == DT_REL)
432 Elf32_Rel *pltRel = plt;
433 int count = pltSz / sizeof(Elf32_Rel);
434 DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", count);
435 for(int i = 0; i < count; i ++)
437 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
438 fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr);
443 Elf32_Rela *pltRela = plt;
444 int count = pltSz / sizeof(Elf32_Rela);
445 DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", count);
446 for(int i=0;i<count;i++)
448 ptr = (void*)(iRealBase + pltRela[i].r_offset);
449 fail |= _doRelocate(pltRela[i].r_info, ptr, 1, pltRela[i].r_addend);
455 for( int i = 0; i < iSegmentCount; i ++ )
457 // If load and not writable
458 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
459 uintptr_t addr = phtab[i].VAddr + iBaseDiff;
460 uintptr_t end = addr + phtab[i].MemSize;
461 for( ; addr < end; addr += PAGE_SIZE )
462 _SysSetMemFlags(addr, 1, 1); // Unset RO
467 DEBUGS("ElfRelocate: Failure");
473 DEBUGS("ElfRelocate: RETURN 0x%x to %p", hdr->entrypoint + iBaseDiff, __builtin_return_address(0));
474 return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff );
477 int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
479 Elf32_Ehdr *hdr = Base;
480 Elf32_Sym *symtab = NULL;
482 Elf32_Word *pBuckets = NULL;
485 const char *dynstrtab = NULL;
486 uintptr_t iBaseDiff = -1;
488 Elf32_Dyn *dynTab = NULL;
491 phtab = (void*)( (uintptr_t)Base + hdr->phoff );
492 for( int i = 0; i < hdr->phentcount; i ++ )
494 if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
495 iBaseDiff = phtab[i].VAddr;
496 if( phtab[i].Type == PT_DYNAMIC ) {
497 dynTab = (void*)(intptr_t)phtab[i].VAddr;
501 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
504 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
505 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
506 for( int i = 0; dynTab[i].d_tag != DT_NULL; i++)
508 switch(dynTab[i].d_tag)
510 // --- Symbol Table ---
512 symtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); // Rebased in Relocate
515 dynstrtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff);
519 pBuckets = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff);
525 SysDebug("ERRO - No DT_SYMTAB in %p", Base);
529 SysDebug("ERRO - No DT_HASH in %p", Base);
533 SysDebug("ERRO - No DT_STRTAB in %p", Base);
537 // ... ok... maybe they haven't been relocated
538 if( (uintptr_t)symtab < (uintptr_t)Base )
540 symtab = (void*)( (uintptr_t)symtab + iBaseDiff );
541 pBuckets = (void*)( (uintptr_t)pBuckets + iBaseDiff );
542 dynstrtab = (void*)( (uintptr_t)dynstrtab + iBaseDiff );
543 SysDebug("Executable not yet relocated");
546 nbuckets = pBuckets[0];
547 // iSymCount = pBuckets[1];
548 pBuckets = &pBuckets[2];
549 pChains = &pBuckets[ nbuckets ];
553 iNameHash = ElfHashString(Name);
554 iNameHash %= nbuckets;
557 int idx = pBuckets[ iNameHash ];
559 Elf32_Sym *sym = &symtab[idx];
561 if(sym->shndx != SHN_UNDEF && strcmp(dynstrtab + sym->nameOfs, Name) == 0) {
562 *ret = (void*)( (uintptr_t)sym->value + iBaseDiff );
563 if(Size) *Size = sym->size;
566 } while( (idx = pChains[idx]) != STN_UNDEF && idx != pBuckets[iNameHash] );
572 typedef int (*t_elf64_doreloc)(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
574 int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
576 int sym = ELF64_R_SYM(r_info);
577 int type = ELF64_R_TYPE(r_info);
578 const char *symname = strtab + symtab[sym].st_name;
580 //DEBUGS("_Elf64DoReloc: %s", symname);
586 if( !GetSymbol(symname, &symval, NULL) ) return 1;
587 *(uint64_t*)ptr = (uintptr_t)symval + addend;
589 case R_X86_64_COPY: {
591 if( !GetSymbol(symname, &symval, &size) ) return 1;
592 memcpy(ptr, symval, size);
594 case R_X86_64_GLOB_DAT:
595 if( !GetSymbol(symname, &symval, NULL) ) return 1;
596 *(uint64_t*)ptr = (uintptr_t)symval;
598 case R_X86_64_JUMP_SLOT:
599 if( !GetSymbol(symname, &symval, NULL) ) return 1;
600 *(uint64_t*)ptr = (uintptr_t)symval;
602 case R_X86_64_RELATIVE:
603 *(uint64_t*)ptr = (uintptr_t)Base + addend;
606 SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
609 //DEBUGS("_Elf64DoReloc: - Good");
613 void *Elf64Relocate(void *Base, char **envp, const char *Filename)
616 Elf64_Ehdr *hdr = Base;
618 Elf64_Dyn *dyntab = NULL;
619 Elf64_Addr compiledBase = -1, baseDiff;
620 Elf64_Sym *symtab = NULL;
622 Elf64_Word *hashtab = NULL;
623 Elf64_Rel *rel = NULL;
625 Elf64_Rela *rela = NULL;
628 int plt_size = 0, plt_type = 0;
630 DEBUGS("Elf64Relocate: hdr = {");
631 DEBUGS("Elf64Relocate: e_ident = '%.16s'", hdr->e_ident);
632 DEBUGS("Elf64Relocate: e_type = 0x%x", hdr->e_type);
633 DEBUGS("Elf64Relocate: e_machine = 0x%x", hdr->e_machine);
634 DEBUGS("Elf64Relocate: e_version = 0x%x", hdr->e_version);
635 DEBUGS("Elf64Relocate: e_entry = %p", hdr->e_entry);
636 DEBUGS("Elf64Relocate: e_phoff = 0x%llx", hdr->e_phoff);
637 DEBUGS("Elf64Relocate: e_shoff = 0x%llx", hdr->e_shoff);
638 DEBUGS("Elf64Relocate: e_flags = 0x%x", hdr->e_flags);
639 DEBUGS("Elf64Relocate: e_ehsize = 0x%x", hdr->e_ehsize);
640 DEBUGS("Elf64Relocate: e_phentsize = 0x%x", hdr->e_phentsize);
641 DEBUGS("Elf64Relocate: e_phnum = %i", hdr->e_phnum);
643 // Scan for the dynamic table (and find the compiled base)
644 phtab = (void*)((uintptr_t)Base + (uintptr_t)hdr->e_phoff);
645 for( i = 0; i < hdr->e_phnum; i ++ )
647 if(phtab[i].p_type == PT_DYNAMIC)
648 dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
649 if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
650 compiledBase = phtab[i].p_vaddr;
653 baseDiff = (uintptr_t)Base - compiledBase;
655 DEBUGS("baseDiff = %p", baseDiff);
658 SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
659 return (void *)(uintptr_t)(hdr->e_entry + baseDiff);
662 dyntab = (void *)(uintptr_t)((uintptr_t)dyntab + baseDiff);
664 // Parse the dynamic table (first pass)
665 // - Search for String, Symbol and Hash tables
666 for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
668 switch(dyntab[i].d_tag)
671 dyntab[i].d_un.d_ptr += baseDiff;
672 symtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
675 dyntab[i].d_un.d_ptr += baseDiff;
676 strtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
679 dyntab[i].d_un.d_ptr += baseDiff;
680 hashtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
685 if( !symtab || !strtab || !hashtab ) {
686 SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
690 // Ready for symbol use
691 AddLoaded( Filename, Base );
693 // Second pass on dynamic table
694 for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
696 DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
697 switch(dyntab[i].d_tag)
699 case DT_SONAME: break;
702 char *libPath = strtab + dyntab[i].d_un.d_val;
703 DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
704 if(LoadLibrary(libPath, NULL, envp) == 0) {
705 SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
710 // Relocation entries
712 dyntab[i].d_un.d_ptr += baseDiff;
713 rel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
716 rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
719 if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
720 SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
721 dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
726 dyntab[i].d_un.d_ptr += baseDiff;
727 rela = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
730 rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
733 if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
734 SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
735 dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
740 dyntab[i].d_un.d_ptr += baseDiff;
741 pltrel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
744 plt_type = dyntab[i].d_un.d_val;
747 plt_size = dyntab[i].d_un.d_val;
752 // Relocation function
753 t_elf64_doreloc fpElf64DoReloc = &_Elf64DoReloc_X86_64;
754 #define _Elf64DoReloc(info, ptr, addend) fpElf64DoReloc(Base, strtab, symtab, info, ptr, addend)
759 DEBUGS("rel_count = %i", rel_count);
760 for( i = 0; i < rel_count; i ++ )
762 uint64_t *ptr = (void *)(uintptr_t)( rel[i].r_offset + baseDiff );
763 fail |= _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
769 DEBUGS("rela_count = %i", rela_count);
770 for( i = 0; i < rela_count; i ++ )
772 uint64_t *ptr = (void *)(uintptr_t)( rela[i].r_offset + baseDiff );
773 fail |= _Elf64DoReloc( rela[i].r_info, ptr, rela[i].r_addend );
777 if( pltrel && plt_type )
779 if( plt_type == DT_REL ) {
780 Elf64_Rel *plt = pltrel;
781 int count = plt_size / sizeof(Elf64_Rel);
782 DEBUGS("plt rel count = %i", count);
783 for( i = 0; i < count; i ++ )
785 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
786 fail |= _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
790 Elf64_Rela *plt = pltrel;
791 int count = plt_size / sizeof(Elf64_Rela);
792 DEBUGS("plt rela count = %i", count);
793 for( i = 0; i < count; i ++ )
795 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
796 fail |= _Elf64DoReloc( plt[i].r_info, ptr, plt[i].r_addend);
802 DEBUGS("Elf64Relocate: Failure");
807 void *ret = (void *)(uintptr_t)(hdr->e_entry + baseDiff);
808 DEBUGS("Elf64Relocate: Relocations done, return %p", ret);
813 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size)
815 Elf64_Ehdr *hdr = Base;
818 // int iSymCount = 0;
820 Elf64_Word *pBuckets;
823 const char *dynstrtab;
824 uintptr_t iBaseDiff = -1;
830 // Catch the current executable
834 Elf64_Dyn *dynTab = NULL;
838 phtab = (void*)( (intptr_t)Base + (uintptr_t)hdr->e_phoff );
839 for( i = 0; i < hdr->e_phnum; i ++ )
841 if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
842 iBaseDiff = phtab[i].p_vaddr;
843 if( phtab[i].p_type == PT_DYNAMIC ) {
844 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
848 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
851 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
852 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
854 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
856 switch(dynTab[j].d_tag)
858 // --- Symbol Table ---
860 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val; // Rebased in Relocate
863 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
867 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
873 nbuckets = pBuckets[0];
874 // iSymCount = pBuckets[1];
875 pBuckets = &pBuckets[2];
876 pChains = &pBuckets[ nbuckets ];
879 iNameHash = ElfHashString(Name);
880 iNameHash %= nbuckets;
883 i = pBuckets[ iNameHash ];
884 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
885 *Ret = (void*)( (intptr_t)symtab[i].st_value + iBaseDiff );
886 if(Size) *Size = symtab[i].st_size;
887 DEBUGS("%s = %p", Name, *Ret);
891 while(pChains[i] != STN_UNDEF)
894 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
895 *Ret = (void*)((intptr_t)symtab[i].st_value + iBaseDiff);
896 if(Size) *Size = symtab[i].st_size;
897 DEBUGS("%s = %p", Name, *Ret);
907 uint32_t ElfHashString(const char *name)
912 h = (h << 4) + *(uint8_t*)name++;
913 if( (g = h & 0xf0000000) )