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 void *Elf64Relocate(void *Base, char **envp, const char *Filename);
47 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
49 uint32_t ElfHashString(const char *name);
53 * \fn int ElfRelocate(void *Base, char **envp, const char *Filename)
54 * \brief Relocates a loaded ELF Executable
56 void *ElfRelocate(void *Base, char **envp, const char *Filename)
58 Elf32_Ehdr *hdr = Base;
60 switch(hdr->e_ident[4])
63 return Elf32Relocate(Base, envp, Filename);
66 return Elf64Relocate(Base, envp, Filename);
69 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
75 * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
77 int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
79 Elf32_Ehdr *hdr = Base;
81 switch(hdr->e_ident[4])
84 return Elf32GetSymbol(Base, Name, ret, Size);
87 return Elf64GetSymbol(Base, Name, ret, Size);
90 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
95 int elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type,
96 int bRela, const char *Sym, intptr_t iBaseDiff)
101 // Standard 32 Bit Relocation (S+A)
103 if( !GetSymbol(Sym, &symval, NULL) )
105 DEBUGS(" elf_doRelocate: R_386_32 *0x%x += %p('%s')",
107 *ptr = (intptr_t)symval + addend;
110 // 32 Bit Relocation wrt. Offset (S+A-P)
112 DEBUGS(" elf_doRelocate: '%s'", Sym);
113 if( !GetSymbol(Sym, &symval, NULL) ) return 1;
114 DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%p - 0x%x",
115 ptr, *ptr, symval, (intptr_t)ptr );
116 *ptr = (intptr_t)symval + addend - (intptr_t)ptr;
117 //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
120 // Absolute Value of a symbol (S)
123 DEBUGS(" elf_doRelocate: '%s'", Sym);
124 if( !GetSymbol(Sym, &symval, NULL) ) return 1;
125 DEBUGS(" elf_doRelocate: %s *0x%x = %p", csaR_NAMES[type], ptr, symval);
126 *ptr = (intptr_t)symval;
129 // Base Address (B+A)
131 DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
132 *ptr = iBaseDiff + addend;
137 if( !GetSymbol(Sym, &symval, &size) ) return 1;
138 DEBUGS(" elf_doRelocate_386: R_386_COPY (%p, %p, %i)", ptr, symval, size);
139 memcpy(ptr, symval, size);
143 SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
149 int elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
156 DEBUGS(" elf_doRelocate_arm: R_ARM_ABS32 %p (%s + %x)", ptr, Sym, addend);
157 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
161 DEBUGS(" elf_doRelocate_arm: R_ARM_GLOB_DAT %p (%s + %x)", ptr, Sym, addend);
162 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
165 case R_ARM_JUMP_SLOT:
166 if(!bRela) addend = 0;
167 DEBUGS(" elf_doRelocate_arm: R_ARM_JUMP_SLOT %p (%s + %x)", ptr, Sym, addend);
168 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
175 if( !GetSymbol(Sym, &src, &size) ) return 1;
176 DEBUGS(" elf_doRelocate_arm: R_ARM_COPY (%p, %p, %i)", ptr, src, size);
177 memcpy(ptr, src, size);
179 // Delta between link and runtime locations + A
181 DEBUGS(" elf_doRelocate_arm: R_ARM_RELATIVE %p (0x%x + 0x%x)", ptr, iBaseDiff, addend);
183 // TODO: Get delta for a symbol
184 SysDebug("elf_doRelocate_arm: TODO - Implment R_ARM_RELATIVE for symbols");
188 *ptr = iBaseDiff + addend;
192 SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
198 int elf_doRelocate_unk(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
203 void *Elf32Relocate(void *Base, char **envp, const char *Filename)
205 Elf32_Ehdr *hdr = Base;
208 intptr_t iRealBase = -1;
211 Elf32_Rel *rel = NULL;
212 Elf32_Rela *rela = NULL;
214 int relSz=0, relEntSz=8;
215 int relaSz=0, relaEntSz=8;
216 int pltSz=0, pltType=0;
217 Elf32_Dyn *dynamicTab = NULL; // Dynamic Table Pointer
218 char *dynstrtab = NULL; // .dynamic String Table
219 Elf32_Sym *dynsymtab;
220 int (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, int bRela, const char *Sym, intptr_t iBaseDiff);
222 DEBUGS("ElfRelocate: (Base=0x%x)", Base);
224 // Check magic header
227 // Parse Program Header to get Dynamic Table
228 phtab = (void*)( (uintptr_t)Base + hdr->phoff );
229 iSegmentCount = hdr->phentcount;
230 for(int i = 0; i < iSegmentCount; i ++)
232 switch(phtab[i].Type)
235 // Determine linked base address
236 if( iRealBase > phtab[i].VAddr)
237 iRealBase = phtab[i].VAddr;
240 // Find Dynamic Section
242 dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
245 DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
251 // Page Align real base
253 DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
255 // Adjust "Real" Base
256 iBaseDiff = (intptr_t)Base - iRealBase;
258 // hdr->entrypoint += iBaseDiff; // Adjust Entrypoint
260 // Check if a PT_DYNAMIC segement was found
262 SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
263 return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
266 // Allow writing to read-only segments, just in case they need to be relocated
267 // - Will be reversed at the end of the function
268 for( int i = 0; i < iSegmentCount; i ++ )
270 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
271 uintptr_t addr = phtab[i].VAddr + iBaseDiff;
272 uintptr_t end = addr + phtab[i].MemSize;
273 for( ; addr < end; addr += PAGE_SIZE )
274 _SysSetMemFlags(addr, 0, 1); // Unset RO
278 // Adjust Dynamic Table
279 dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
281 // === Get Symbol table and String Table ===
283 for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
285 switch(dynamicTab[j].d_tag)
287 // --- Symbol Table ---
289 DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
290 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
291 dynsymtab = (void*)((intptr_t)dynamicTab[j].d_val + iBaseDiff);
292 //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
294 // --- String Table ---
296 DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
297 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
298 dynstrtab = (void*)((intptr_t)dynamicTab[j].d_val + iBaseDiff);
299 //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
303 //if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
304 // iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
309 if(dynsymtab == NULL) {
310 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
311 return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
314 // === Add to loaded list (can be imported now) ===
315 AddLoaded( Filename, Base );
317 // === Parse Relocation Data ===
318 DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
319 for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
321 switch(dynamicTab[j].d_tag)
323 // --- Shared Library Name ---
325 DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
327 // --- Needed Library ---
329 libPath = dynstrtab + dynamicTab[j].d_val;
330 DEBUGS(" dynstrtab = %p, d_val = 0x%x", dynstrtab, dynamicTab[j].d_val);
331 DEBUGS(" Required Library '%s'", libPath);
332 if(LoadLibrary(libPath, NULL, envp) == 0) {
334 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
336 SysDebug("Unable to load required library '%s'", libPath);
340 DEBUGS(" Lib loaded");
343 // case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
344 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
345 case DT_PLTREL: pltType = dynamicTab[j].d_val; break;
346 case DT_PLTRELSZ: pltSz = dynamicTab[j].d_val; break;
348 // --- Relocation ---
349 case DT_REL: rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
350 case DT_RELSZ: relSz = dynamicTab[j].d_val; break;
351 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
352 case DT_RELA: rela = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
353 case DT_RELASZ: relaSz = dynamicTab[j].d_val; break;
354 case DT_RELAENT: relaEntSz = dynamicTab[j].d_val; break;
356 // --- Symbol Table ---
358 // --- Hash Table ---
360 // --- String Table ---
366 if(dynamicTab[j].d_tag > DT_JMPREL) continue;
367 //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
368 // i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
373 DEBUGS(" elf_relocate: Beginning Relocation");
380 do_relocate = elf_doRelocate_386;
383 do_relocate = elf_doRelocate_arm;
386 SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
387 do_relocate = elf_doRelocate_unk;
392 DEBUGS("do_relocate = %p (%p or %p)", do_relocate, &elf_doRelocate_386, &elf_doRelocate_arm);
394 #define _doRelocate(r_info, ptr, bRela, addend) \
395 do_relocate(r_info, ptr, addend, ELF32_R_TYPE(r_info), bRela, \
396 dynstrtab + dynsymtab[ELF32_R_SYM(r_info)].nameOfs, iBaseDiff);
398 // Parse Relocation Entries
402 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
403 int max = relSz / relEntSz;
404 for( int i = 0; i < max; i++ )
406 //DEBUGS(" Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
407 ptr = (void*)(iBaseDiff + rel[i].r_offset);
408 fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr);
411 // Parse Relocation Entries
415 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
416 int count = relaSz / relaEntSz;
417 for( int i = 0; i < count; i++ )
419 ptr = (void*)(iBaseDiff + rela[i].r_offset);
420 fail |= _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend);
424 // === Process PLT (Procedure Linkage Table) ===
428 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
429 if(pltType == DT_REL)
431 Elf32_Rel *pltRel = plt;
432 int count = pltSz / sizeof(Elf32_Rel);
433 DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", count);
434 for(int i = 0; i < count; i ++)
436 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
437 fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr);
442 Elf32_Rela *pltRela = plt;
443 int count = pltSz / sizeof(Elf32_Rela);
444 DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", count);
445 for(int i=0;i<count;i++)
447 ptr = (void*)(iRealBase + pltRela[i].r_offset);
448 fail |= _doRelocate(pltRela[i].r_info, ptr, 1, pltRela[i].r_addend);
454 for( int i = 0; i < iSegmentCount; i ++ )
456 // If load and not writable
457 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
458 uintptr_t addr = phtab[i].VAddr + iBaseDiff;
459 uintptr_t end = addr + phtab[i].MemSize;
460 for( ; addr < end; addr += PAGE_SIZE )
461 _SysSetMemFlags(addr, 1, 1); // Unset RO
466 DEBUGS("ElfRelocate: Failure");
472 DEBUGS("ElfRelocate: RETURN 0x%x to %p", hdr->entrypoint + iBaseDiff, __builtin_return_address(0));
473 return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff );
476 int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
478 Elf32_Ehdr *hdr = Base;
479 Elf32_Sym *symtab = NULL;
481 Elf32_Word *pBuckets = NULL;
484 const char *dynstrtab = NULL;
485 uintptr_t iBaseDiff = -1;
487 Elf32_Dyn *dynTab = NULL;
490 phtab = (void*)( (uintptr_t)Base + hdr->phoff );
491 for( int i = 0; i < hdr->phentcount; i ++ )
493 if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
494 iBaseDiff = phtab[i].VAddr;
495 if( phtab[i].Type == PT_DYNAMIC ) {
496 dynTab = (void*)(intptr_t)phtab[i].VAddr;
500 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
503 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
504 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
505 for( int i = 0; dynTab[i].d_tag != DT_NULL; i++)
507 switch(dynTab[i].d_tag)
509 // --- Symbol Table ---
511 symtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); // Rebased in Relocate
514 dynstrtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff);
518 pBuckets = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff);
524 SysDebug("ERRO - No DT_SYMTAB in %p", Base);
528 SysDebug("ERRO - No DT_HASH in %p", Base);
532 SysDebug("ERRO - No DT_STRTAB in %p", Base);
536 // ... ok... maybe they haven't been relocated
537 if( (uintptr_t)symtab < (uintptr_t)Base )
539 symtab = (void*)( (uintptr_t)symtab + iBaseDiff );
540 pBuckets = (void*)( (uintptr_t)pBuckets + iBaseDiff );
541 dynstrtab = (void*)( (uintptr_t)dynstrtab + iBaseDiff );
542 SysDebug("Executable not yet relocated");
545 nbuckets = pBuckets[0];
546 // iSymCount = pBuckets[1];
547 pBuckets = &pBuckets[2];
548 pChains = &pBuckets[ nbuckets ];
552 iNameHash = ElfHashString(Name);
553 iNameHash %= nbuckets;
556 int idx = pBuckets[ iNameHash ];
558 Elf32_Sym *sym = &symtab[idx];
560 if(sym->shndx != SHN_UNDEF && strcmp(dynstrtab + sym->nameOfs, Name) == 0) {
561 *ret = (void*)( (uintptr_t)sym->value + iBaseDiff );
562 if(Size) *Size = sym->size;
565 } while( (idx = pChains[idx]) != STN_UNDEF && idx != pBuckets[iNameHash] );
571 typedef int (*t_elf64_doreloc)(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
573 int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
575 int sym = ELF64_R_SYM(r_info);
576 int type = ELF64_R_TYPE(r_info);
577 const char *symname = strtab + symtab[sym].st_name;
579 //DEBUGS("_Elf64DoReloc: %s", symname);
585 if( !GetSymbol(symname, &symval, NULL) ) return 1;
586 *(uint64_t*)ptr = (uintptr_t)symval + addend;
588 case R_X86_64_COPY: {
590 if( !GetSymbol(symname, &symval, &size) ) return 1;
591 memcpy(ptr, symval, size);
593 case R_X86_64_GLOB_DAT:
594 if( !GetSymbol(symname, &symval, NULL) ) return 1;
595 *(uint64_t*)ptr = (uintptr_t)symval;
597 case R_X86_64_JUMP_SLOT:
598 if( !GetSymbol(symname, &symval, NULL) ) return 1;
599 *(uint64_t*)ptr = (uintptr_t)symval;
601 case R_X86_64_RELATIVE:
602 *(uint64_t*)ptr = (uintptr_t)Base + addend;
605 SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
608 //DEBUGS("_Elf64DoReloc: - Good");
612 void *Elf64Relocate(void *Base, char **envp, const char *Filename)
615 Elf64_Ehdr *hdr = Base;
617 Elf64_Dyn *dyntab = NULL;
618 Elf64_Addr compiledBase = -1, baseDiff;
619 Elf64_Sym *symtab = NULL;
621 Elf64_Word *hashtab = NULL;
622 Elf64_Rel *rel = NULL;
624 Elf64_Rela *rela = NULL;
627 int plt_size = 0, plt_type = 0;
629 DEBUGS("Elf64Relocate: hdr = {");
630 DEBUGS("Elf64Relocate: e_ident = '%.16s'", hdr->e_ident);
631 DEBUGS("Elf64Relocate: e_type = 0x%x", hdr->e_type);
632 DEBUGS("Elf64Relocate: e_machine = 0x%x", hdr->e_machine);
633 DEBUGS("Elf64Relocate: e_version = 0x%x", hdr->e_version);
634 DEBUGS("Elf64Relocate: e_entry = %p", hdr->e_entry);
635 DEBUGS("Elf64Relocate: e_phoff = 0x%llx", hdr->e_phoff);
636 DEBUGS("Elf64Relocate: e_shoff = 0x%llx", hdr->e_shoff);
637 DEBUGS("Elf64Relocate: e_flags = 0x%x", hdr->e_flags);
638 DEBUGS("Elf64Relocate: e_ehsize = 0x%x", hdr->e_ehsize);
639 DEBUGS("Elf64Relocate: e_phentsize = 0x%x", hdr->e_phentsize);
640 DEBUGS("Elf64Relocate: e_phnum = %i", hdr->e_phnum);
642 // Scan for the dynamic table (and find the compiled base)
643 phtab = (void*)((uintptr_t)Base + (uintptr_t)hdr->e_phoff);
644 for( i = 0; i < hdr->e_phnum; i ++ )
646 if(phtab[i].p_type == PT_DYNAMIC)
647 dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
648 if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
649 compiledBase = phtab[i].p_vaddr;
652 baseDiff = (uintptr_t)Base - compiledBase;
654 DEBUGS("baseDiff = %p", baseDiff);
657 SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
658 return (void *)(uintptr_t)(hdr->e_entry + baseDiff);
661 dyntab = (void *)(uintptr_t)((uintptr_t)dyntab + baseDiff);
663 // Parse the dynamic table (first pass)
664 // - Search for String, Symbol and Hash tables
665 for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
667 switch(dyntab[i].d_tag)
670 dyntab[i].d_un.d_ptr += baseDiff;
671 symtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
674 dyntab[i].d_un.d_ptr += baseDiff;
675 strtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
678 dyntab[i].d_un.d_ptr += baseDiff;
679 hashtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
684 if( !symtab || !strtab || !hashtab ) {
685 SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
689 // Ready for symbol use
690 AddLoaded( Filename, Base );
692 // Second pass on dynamic table
693 for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
695 DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
696 switch(dyntab[i].d_tag)
698 case DT_SONAME: break;
701 char *libPath = strtab + dyntab[i].d_un.d_val;
702 DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
703 if(LoadLibrary(libPath, NULL, envp) == 0) {
704 SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
709 // Relocation entries
711 dyntab[i].d_un.d_ptr += baseDiff;
712 rel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
715 rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
718 if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
719 SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
720 dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
725 dyntab[i].d_un.d_ptr += baseDiff;
726 rela = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
729 rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
732 if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
733 SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
734 dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
739 dyntab[i].d_un.d_ptr += baseDiff;
740 pltrel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
743 plt_type = dyntab[i].d_un.d_val;
746 plt_size = dyntab[i].d_un.d_val;
751 // Relocation function
752 t_elf64_doreloc fpElf64DoReloc = &_Elf64DoReloc_X86_64;
753 #define _Elf64DoReloc(info, ptr, addend) fpElf64DoReloc(Base, strtab, symtab, info, ptr, addend)
758 DEBUGS("rel_count = %i", rel_count);
759 for( i = 0; i < rel_count; i ++ )
761 uint64_t *ptr = (void *)(uintptr_t)( rel[i].r_offset + baseDiff );
762 fail |= _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
768 DEBUGS("rela_count = %i", rela_count);
769 for( i = 0; i < rela_count; i ++ )
771 uint64_t *ptr = (void *)(uintptr_t)( rela[i].r_offset + baseDiff );
772 fail |= _Elf64DoReloc( rela[i].r_info, ptr, rela[i].r_addend );
776 if( pltrel && plt_type )
778 if( plt_type == DT_REL ) {
779 Elf64_Rel *plt = pltrel;
780 int count = plt_size / sizeof(Elf64_Rel);
781 DEBUGS("plt rel count = %i", count);
782 for( i = 0; i < count; i ++ )
784 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
785 fail |= _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
789 Elf64_Rela *plt = pltrel;
790 int count = plt_size / sizeof(Elf64_Rela);
791 DEBUGS("plt rela count = %i", count);
792 for( i = 0; i < count; i ++ )
794 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
795 fail |= _Elf64DoReloc( plt[i].r_info, ptr, plt[i].r_addend);
801 DEBUGS("Elf64Relocate: Failure");
806 void *ret = (void *)(uintptr_t)(hdr->e_entry + baseDiff);
807 DEBUGS("Elf64Relocate: Relocations done, return %p", ret);
812 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size)
814 Elf64_Ehdr *hdr = Base;
817 // int iSymCount = 0;
819 Elf64_Word *pBuckets;
822 const char *dynstrtab;
823 uintptr_t iBaseDiff = -1;
829 // Catch the current executable
833 Elf64_Dyn *dynTab = NULL;
837 phtab = (void*)( (intptr_t)Base + (uintptr_t)hdr->e_phoff );
838 for( i = 0; i < hdr->e_phnum; i ++ )
840 if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
841 iBaseDiff = phtab[i].p_vaddr;
842 if( phtab[i].p_type == PT_DYNAMIC ) {
843 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
847 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
850 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
851 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
853 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
855 switch(dynTab[j].d_tag)
857 // --- Symbol Table ---
859 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val; // Rebased in Relocate
862 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
866 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
872 nbuckets = pBuckets[0];
873 // iSymCount = pBuckets[1];
874 pBuckets = &pBuckets[2];
875 pChains = &pBuckets[ nbuckets ];
878 iNameHash = ElfHashString(Name);
879 iNameHash %= nbuckets;
882 i = pBuckets[ iNameHash ];
883 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
884 *Ret = (void*)( (intptr_t)symtab[i].st_value + iBaseDiff );
885 if(Size) *Size = symtab[i].st_size;
886 DEBUGS("%s = %p", Name, *Ret);
890 while(pChains[i] != STN_UNDEF)
893 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
894 *Ret = (void*)((intptr_t)symtab[i].st_value + iBaseDiff);
895 if(Size) *Size = symtab[i].st_size;
896 DEBUGS("%s = %p", Name, *Ret);
906 uint32_t ElfHashString(const char *name)
911 h = (h << 4) + *(uint8_t*)name++;
912 if( (g = h & 0xf0000000) )