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);
45 void *Elf64Relocate(void *Base, char **envp, const char *Filename);
46 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size);
48 uint32_t ElfHashString(const char *name);
52 * \fn int ElfRelocate(void *Base, char **envp, const char *Filename)
53 * \brief Relocates a loaded ELF Executable
55 void *ElfRelocate(void *Base, char **envp, const char *Filename)
57 Elf32_Ehdr *hdr = Base;
59 switch(hdr->e_ident[4])
62 return Elf32Relocate(Base, envp, Filename);
65 return Elf64Relocate(Base, envp, Filename);
68 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
74 * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret)
76 int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
78 Elf32_Ehdr *hdr = Base;
80 switch(hdr->e_ident[4])
83 return Elf32GetSymbol(Base, Name, ret, Size);
86 return Elf64GetSymbol(Base, Name, ret, Size);
89 SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]);
94 int elf_doRelocate_386(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type,
95 int bRela, const char *Sym, intptr_t iBaseDiff)
100 // Standard 32 Bit Relocation (S+A)
102 if( !GetSymbol(Sym, &symval, NULL) )
104 DEBUGS(" elf_doRelocate: R_386_32 *0x%x += %p('%s')",
106 *ptr = (intptr_t)symval + addend;
109 // 32 Bit Relocation wrt. Offset (S+A-P)
111 DEBUGS(" elf_doRelocate: '%s'", Sym);
112 if( !GetSymbol(Sym, &symval, NULL) ) return 1;
113 DEBUGS(" elf_doRelocate: R_386_PC32 *0x%x = 0x%x + 0x%p - 0x%x",
114 ptr, *ptr, symval, (intptr_t)ptr );
115 *ptr = (intptr_t)symval + addend - (intptr_t)ptr;
116 //*ptr = val + addend - ((Uint)ptr - iBaseDiff);
119 // Absolute Value of a symbol (S)
122 DEBUGS(" elf_doRelocate: '%s'", Sym);
123 if( !GetSymbol(Sym, &symval, NULL) ) return 1;
124 DEBUGS(" elf_doRelocate: %s *0x%x = %p", csaR_NAMES[type], ptr, symval);
125 *ptr = (intptr_t)symval;
128 // Base Address (B+A)
130 DEBUGS(" elf_doRelocate: R_386_RELATIVE *0x%x = 0x%x + 0x%x", ptr, iBaseDiff, addend);
131 *ptr = iBaseDiff + addend;
136 if( !GetSymbol(Sym, &symval, &size) ) return 1;
137 DEBUGS(" elf_doRelocate_386: R_386_COPY (%p, %p, %i)", ptr, symval, size);
138 memcpy(ptr, symval, size);
142 SysDebug("elf_doRelocate_386: Unknown relocation %i", type);
148 int elf_doRelocate_arm(uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int type, int bRela, const char *Sym, intptr_t iBaseDiff)
155 DEBUGS(" elf_doRelocate_arm: R_ARM_ABS32 %p (%s + %x)", ptr, Sym, addend);
156 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
160 DEBUGS(" elf_doRelocate_arm: R_ARM_GLOB_DAT %p (%s + %x)", ptr, Sym, addend);
161 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
164 case R_ARM_JUMP_SLOT:
165 if(!bRela) addend = 0;
166 DEBUGS(" elf_doRelocate_arm: R_ARM_JUMP_SLOT %p (%s + %x)", ptr, Sym, addend);
167 if( !GetSymbol(Sym, (void**)&val, NULL) ) return 1;
174 if( !GetSymbol(Sym, &src, &size) ) return 1;
175 DEBUGS(" elf_doRelocate_arm: R_ARM_COPY (%p, %p, %i)", ptr, src, size);
176 memcpy(ptr, src, size);
178 // Delta between link and runtime locations + A
180 DEBUGS(" elf_doRelocate_arm: R_ARM_RELATIVE %p (0x%x + 0x%x)", ptr, iBaseDiff, addend);
182 // TODO: Get delta for a symbol
183 SysDebug("elf_doRelocate_arm: TODO - Implment R_ARM_RELATIVE for symbols");
187 *ptr = iBaseDiff + addend;
191 SysDebug("elf_doRelocate_arm: Unknown Relocation, %i", type);
197 void *Elf32Relocate(void *Base, char **envp, const char *Filename)
199 Elf32_Ehdr *hdr = Base;
201 int i, j; // Counters
203 intptr_t iRealBase = -1;
207 Elf32_Rel *rel = NULL;
208 Elf32_Rela *rela = NULL;
210 int relSz=0, relEntSz=8;
211 int relaSz=0, relaEntSz=8;
212 int pltSz=0, pltType=0;
213 Elf32_Dyn *dynamicTab = NULL; // Dynamic Table Pointer
214 char *dynstrtab = NULL; // .dynamic String Table
215 Elf32_Sym *dynsymtab;
216 int (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, int bRela, const char *Sym, intptr_t iBaseDiff);
217 auto int _doRelocate(uint32_t r_info, uint32_t *ptr, int bRela, Elf32_Addr addend);
219 DEBUGS("ElfRelocate: (Base=0x%x)", Base);
221 // Check magic header
224 // Parse Program Header to get Dynamic Table
225 phtab = (void*)( (uintptr_t)Base + hdr->phoff );
226 iSegmentCount = hdr->phentcount;
227 for(i=0;i<iSegmentCount;i++)
229 // Determine linked base address
230 if(phtab[i].Type == PT_LOAD && iRealBase > phtab[i].VAddr)
231 iRealBase = phtab[i].VAddr;
233 // Find Dynamic Section
234 if(phtab[i].Type == PT_DYNAMIC) {
236 DEBUGS(" WARNING - elf_relocate: Multiple PT_DYNAMIC segments");
239 dynamicTab = (void *) (intptr_t) phtab[i].VAddr;
240 j = i; // Save Dynamic Table ID
244 // Page Align real base
246 DEBUGS(" elf_relocate: True Base = 0x%x, Compiled Base = 0x%x", Base, iRealBase);
248 // Adjust "Real" Base
249 iBaseDiff = (intptr_t)Base - iRealBase;
251 // hdr->entrypoint += iBaseDiff; // Adjust Entrypoint
253 // Check if a PT_DYNAMIC segement was found
255 SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base);
256 return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff);
259 // Allow writing to read-only segments, just in case they need to be relocated
260 // - Will be reversed at the end of the function
261 for( i = 0; i < iSegmentCount; i ++ )
263 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
264 uintptr_t addr = phtab[i].VAddr + iBaseDiff;
265 uintptr_t end = addr + phtab[i].MemSize;
266 for( ; addr < end; addr += PAGE_SIZE )
267 SysSetMemFlags(addr, 0, 1); // Unset RO
271 // Adjust Dynamic Table
272 dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff );
274 // === Get Symbol table and String Table ===
275 for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
277 switch(dynamicTab[j].d_tag)
279 // --- Symbol Table ---
281 DEBUGS(" elf_relocate: DYNAMIC Symbol Table 0x%x (0x%x)",
282 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
283 if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
284 dynsymtab = (void*)(intptr_t)dynamicTab[j].d_val;
286 // --- String Table ---
288 DEBUGS(" elf_relocate: DYNAMIC String Table 0x%x (0x%x)",
289 dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff);
290 if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
291 dynstrtab = (void*)(intptr_t)dynamicTab[j].d_val;
295 if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff;
296 // iSymCount = ((Elf32_Word*)(intptr_t)dynamicTab[j].d_val)[1];
301 if(dynsymtab == NULL) {
302 SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr);
303 return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff);
306 // === Add to loaded list (can be imported now) ===
307 AddLoaded( Filename, Base );
309 // === Parse Relocation Data ===
310 DEBUGS(" elf_relocate: dynamicTab = 0x%x", dynamicTab);
311 for( j = 0; dynamicTab[j].d_tag != DT_NULL; j++)
313 switch(dynamicTab[j].d_tag)
315 // --- Shared Library Name ---
317 DEBUGS(" elf_relocate: .so Name '%s'", dynstrtab+dynamicTab[j].d_val);
319 // --- Needed Library ---
321 libPath = dynstrtab + dynamicTab[j].d_val;
322 DEBUGS(" Required Library '%s'", libPath);
323 if(LoadLibrary(libPath, NULL, envp) == 0) {
325 DEBUGS(" elf_relocate: Unable to load '%s'", libPath);
327 SysDebug("Unable to load required library '%s'", libPath);
331 DEBUGS(" Lib loaded");
334 // case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
335 case DT_JMPREL: plt = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
336 case DT_PLTREL: pltType = dynamicTab[j].d_val; break;
337 case DT_PLTRELSZ: pltSz = dynamicTab[j].d_val; break;
339 // --- Relocation ---
340 case DT_REL: rel = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
341 case DT_RELSZ: relSz = dynamicTab[j].d_val; break;
342 case DT_RELENT: relEntSz = dynamicTab[j].d_val; break;
343 case DT_RELA: rela = (void*)(iBaseDiff + dynamicTab[j].d_val); break;
344 case DT_RELASZ: relaSz = dynamicTab[j].d_val; break;
345 case DT_RELAENT: relaEntSz = dynamicTab[j].d_val; break;
347 // --- Symbol Table ---
349 // --- Hash Table ---
351 // --- String Table ---
357 if(dynamicTab[j].d_tag > DT_JMPREL) continue;
358 //DEBUGS(" elf_relocate: %i-%i = %s,0x%x",
359 // i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val);
364 DEBUGS(" elf_relocate: Beginning Relocation");
366 int _doRelocate(uint32_t r_info, uint32_t *ptr, int bRela, Elf32_Addr addend)
368 int type = ELF32_R_TYPE(r_info);
369 int sym = ELF32_R_SYM(r_info);
370 const char *symname = dynstrtab + dynsymtab[sym].nameOfs;
371 return do_relocate(r_info, ptr, addend, type, bRela, symname, iBaseDiff);
377 do_relocate = elf_doRelocate_386;
380 do_relocate = elf_doRelocate_arm;
383 SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine);
388 DEBUGS("do_relocate = %p (%p or %p)", do_relocate, &elf_doRelocate_386, &elf_doRelocate_arm);
392 // Parse Relocation Entries
396 DEBUGS(" elf_relocate: rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz);
397 j = relSz / relEntSz;
398 for( i = 0; i < j; i++ )
400 //DEBUGS(" Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset);
401 ptr = (void*)(iBaseDiff + rel[i].r_offset);
402 fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr);
405 // Parse Relocation Entries
409 DEBUGS(" elf_relocate: rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz);
410 j = relaSz / relaEntSz;
411 for( i = 0; i < j; i++ )
413 ptr = (void*)(iBaseDiff + rela[i].r_offset);
414 fail |= _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend);
418 // === Process PLT (Procedure Linkage Table) ===
422 DEBUGS(" elf_relocate: Relocate PLT, plt=0x%x", plt);
423 if(pltType == DT_REL)
425 Elf32_Rel *pltRel = plt;
426 j = pltSz / sizeof(Elf32_Rel);
427 DEBUGS(" elf_relocate: PLT Reloc Type = Rel, %i entries", j);
430 ptr = (void*)(iBaseDiff + pltRel[i].r_offset);
431 fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr);
436 Elf32_Rela *pltRela = plt;
437 j = pltSz / sizeof(Elf32_Rela);
438 DEBUGS(" elf_relocate: PLT Reloc Type = Rela, %i entries", j);
441 ptr = (void*)(iRealBase + pltRela[i].r_offset);
442 fail |= _doRelocate(pltRela[i].r_info, ptr, 1, pltRela[i].r_addend);
448 for( i = 0; i < iSegmentCount; i ++ )
450 // If load and not writable
451 if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) {
452 uintptr_t addr = phtab[i].VAddr + iBaseDiff;
453 uintptr_t end = addr + phtab[i].MemSize;
454 for( ; addr < end; addr += PAGE_SIZE )
455 SysSetMemFlags(addr, 1, 1); // Unset RO
460 DEBUGS("ElfRelocate: Failure");
464 DEBUGS("ElfRelocate: RETURN 0x%x to %p", hdr->entrypoint + iBaseDiff, __builtin_return_address(0));
465 return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff );
468 int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size)
470 Elf32_Ehdr *hdr = Base;
471 Elf32_Sym *symtab = NULL;
473 Elf32_Word *pBuckets = NULL;
476 const char *dynstrtab = NULL;
477 uintptr_t iBaseDiff = -1;
479 Elf32_Dyn *dynTab = NULL;
483 phtab = (void*)( (uintptr_t)Base + hdr->phoff );
484 for( i = 0; i < hdr->phentcount; i ++ )
486 if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr)
487 iBaseDiff = phtab[i].VAddr;
488 if( phtab[i].Type == PT_DYNAMIC ) {
489 dynTab = (void*)(intptr_t)phtab[i].VAddr;
493 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
496 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
497 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
498 for( i = 0; dynTab[i].d_tag != DT_NULL; i++)
500 switch(dynTab[i].d_tag)
502 // --- Symbol Table ---
504 symtab = (void*)(intptr_t) dynTab[i].d_val; // Rebased in Relocate
507 dynstrtab = (void*)(intptr_t) dynTab[i].d_val;
511 pBuckets = (void*)(intptr_t) dynTab[i].d_val;
517 SysDebug("ERRO - No DT_SYMTAB in %p", Base);
521 SysDebug("ERRO - No DT_HASH in %p", Base);
525 SysDebug("ERRO - No DT_STRTAB in %p", Base);
529 // ... ok... maybe they haven't been relocated
530 if( (uintptr_t)symtab < (uintptr_t)Base )
532 symtab = (void*)( (uintptr_t)symtab + iBaseDiff );
533 pBuckets = (void*)( (uintptr_t)pBuckets + iBaseDiff );
534 dynstrtab = (void*)( (uintptr_t)dynstrtab + iBaseDiff );
535 SysDebug("Executable not yet relocated");
538 nbuckets = pBuckets[0];
539 // iSymCount = pBuckets[1];
540 pBuckets = &pBuckets[2];
541 pChains = &pBuckets[ nbuckets ];
544 iNameHash = ElfHashString(Name);
545 iNameHash %= nbuckets;
548 i = pBuckets[ iNameHash ];
549 if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) {
550 *ret = (void*)( (uintptr_t) symtab[ i ].value + iBaseDiff );
551 if(Size) *Size = symtab[i].size;
555 while(pChains[i] != STN_UNDEF)
558 if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) {
559 *ret = (void*)( (uintptr_t)symtab[ i ].value + iBaseDiff );
560 if(Size) *Size = symtab[i].size;
569 void *Elf64Relocate(void *Base, char **envp, const char *Filename)
572 Elf64_Ehdr *hdr = Base;
574 Elf64_Dyn *dyntab = NULL;
575 Elf64_Addr compiledBase = -1, baseDiff;
576 Elf64_Sym *symtab = NULL;
578 Elf64_Word *hashtab = NULL;
579 Elf64_Rel *rel = NULL;
581 Elf64_Rela *rela = NULL;
584 int plt_size = 0, plt_type = 0;
586 DEBUGS("Elf64Relocate: hdr = {");
587 DEBUGS("Elf64Relocate: e_ident = '%.16s'", hdr->e_ident);
588 DEBUGS("Elf64Relocate: e_type = 0x%x", hdr->e_type);
589 DEBUGS("Elf64Relocate: e_machine = 0x%x", hdr->e_machine);
590 DEBUGS("Elf64Relocate: e_version = 0x%x", hdr->e_version);
591 DEBUGS("Elf64Relocate: e_entry = %p", hdr->e_entry);
592 DEBUGS("Elf64Relocate: e_phoff = 0x%llx", hdr->e_phoff);
593 DEBUGS("Elf64Relocate: e_shoff = 0x%llx", hdr->e_shoff);
594 DEBUGS("Elf64Relocate: e_flags = 0x%x", hdr->e_flags);
595 DEBUGS("Elf64Relocate: e_ehsize = 0x%x", hdr->e_ehsize);
596 DEBUGS("Elf64Relocate: e_phentsize = 0x%x", hdr->e_phentsize);
597 DEBUGS("Elf64Relocate: e_phnum = %i", hdr->e_phnum);
599 // Scan for the dynamic table (and find the compiled base)
600 phtab = (void*)((uintptr_t)Base + (uintptr_t)hdr->e_phoff);
601 for( i = 0; i < hdr->e_phnum; i ++ )
603 if(phtab[i].p_type == PT_DYNAMIC)
604 dyntab = (void *)(intptr_t)phtab[i].p_vaddr;
605 if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr)
606 compiledBase = phtab[i].p_vaddr;
609 baseDiff = (uintptr_t)Base - compiledBase;
611 DEBUGS("baseDiff = %p", baseDiff);
614 SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base);
615 return (void *)(uintptr_t)(hdr->e_entry + baseDiff);
618 dyntab = (void *)(uintptr_t)((uintptr_t)dyntab + baseDiff);
620 // Parse the dynamic table (first pass)
621 // - Search for String, Symbol and Hash tables
622 for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
624 switch(dyntab[i].d_tag)
627 dyntab[i].d_un.d_ptr += baseDiff;
628 symtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
631 dyntab[i].d_un.d_ptr += baseDiff;
632 strtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
635 dyntab[i].d_un.d_ptr += baseDiff;
636 hashtab = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
641 if( !symtab || !strtab || !hashtab ) {
642 SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table");
646 // Ready for symbol use
647 AddLoaded( Filename, Base );
649 // Second pass on dynamic table
650 for(i = 0; dyntab[i].d_tag != DT_NULL; i ++)
652 DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag);
653 switch(dyntab[i].d_tag)
655 case DT_SONAME: break;
658 char *libPath = strtab + dyntab[i].d_un.d_val;
659 DEBUGS("Elf64Relocate: libPath = '%s'", libPath);
660 if(LoadLibrary(libPath, NULL, envp) == 0) {
661 SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath);
666 // Relocation entries
668 dyntab[i].d_un.d_ptr += baseDiff;
669 rel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
672 rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel);
675 if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) {
676 SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)",
677 dyntab[i].d_un.d_val, sizeof(Elf64_Rel));
682 dyntab[i].d_un.d_ptr += baseDiff;
683 rela = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
686 rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela);
689 if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) {
690 SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)",
691 dyntab[i].d_un.d_val, sizeof(Elf64_Rela));
696 dyntab[i].d_un.d_ptr += baseDiff;
697 pltrel = (void *)(uintptr_t)dyntab[i].d_un.d_ptr;
700 plt_type = dyntab[i].d_un.d_val;
703 plt_size = dyntab[i].d_un.d_val;
708 // Relocation function
709 auto int _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend);
710 int _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend)
712 int sym = ELF64_R_SYM(r_info);
713 int type = ELF64_R_TYPE(r_info);
714 const char *symname = strtab + symtab[sym].st_name;
716 //DEBUGS("_Elf64DoReloc: %s", symname);
722 if( !GetSymbol(symname, &symval, NULL) ) return 1;
723 *(uint64_t*)ptr = (uintptr_t)symval + addend;
725 case R_X86_64_COPY: {
727 if( !GetSymbol(symname, &symval, &size) ) return 1;
728 memcpy(ptr, symval, size);
730 case R_X86_64_GLOB_DAT:
731 if( !GetSymbol(symname, &symval, NULL) ) return 1;
732 *(uint64_t*)ptr = (uintptr_t)symval;
734 case R_X86_64_JUMP_SLOT:
735 if( !GetSymbol(symname, &symval, NULL) ) return 1;
736 *(uint64_t*)ptr = (uintptr_t)symval;
738 case R_X86_64_RELATIVE:
739 *(uint64_t*)ptr = (uintptr_t)Base + addend;
742 SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type);
745 //DEBUGS("_Elf64DoReloc: - Good");
752 DEBUGS("rel_count = %i", rel_count);
753 for( i = 0; i < rel_count; i ++ )
755 uint64_t *ptr = (void *)(uintptr_t)( rel[i].r_offset + baseDiff );
756 fail |= _Elf64DoReloc( rel[i].r_info, ptr, *ptr);
762 DEBUGS("rela_count = %i", rela_count);
763 for( i = 0; i < rela_count; i ++ )
765 uint64_t *ptr = (void *)(uintptr_t)( rela[i].r_offset + baseDiff );
766 fail |= _Elf64DoReloc( rela[i].r_info, ptr, rela[i].r_addend );
770 if( pltrel && plt_type )
772 if( plt_type == DT_REL ) {
773 Elf64_Rel *plt = pltrel;
774 int count = plt_size / sizeof(Elf64_Rel);
775 DEBUGS("plt rel count = %i", count);
776 for( i = 0; i < count; i ++ )
778 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
779 fail |= _Elf64DoReloc( plt[i].r_info, ptr, *ptr);
783 Elf64_Rela *plt = pltrel;
784 int count = plt_size / sizeof(Elf64_Rela);
785 DEBUGS("plt rela count = %i", count);
786 for( i = 0; i < count; i ++ )
788 uint64_t *ptr = (void *)(uintptr_t)( plt[i].r_offset + baseDiff );
789 fail |= _Elf64DoReloc( plt[i].r_info, ptr, plt[i].r_addend);
795 DEBUGS("Elf64Relocate: Failure");
800 void *ret = (void *)(uintptr_t)(hdr->e_entry + baseDiff);
801 DEBUGS("Elf64Relocate: Relocations done, return %p", ret);
806 int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size)
808 Elf64_Ehdr *hdr = Base;
811 // int iSymCount = 0;
813 Elf64_Word *pBuckets;
816 const char *dynstrtab;
817 uintptr_t iBaseDiff = -1;
823 // Catch the current executable
827 Elf64_Dyn *dynTab = NULL;
831 phtab = (void*)( (intptr_t)Base + (uintptr_t)hdr->e_phoff );
832 for( i = 0; i < hdr->e_phnum; i ++ )
834 if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr)
835 iBaseDiff = phtab[i].p_vaddr;
836 if( phtab[i].p_type == PT_DYNAMIC ) {
837 dynTab = (void*)(intptr_t)phtab[i].p_vaddr;
841 SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base);
844 iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff
845 dynTab = (void*)( (intptr_t)dynTab + iBaseDiff );
847 for( j = 0; dynTab[j].d_tag != DT_NULL; j++)
849 switch(dynTab[j].d_tag)
851 // --- Symbol Table ---
853 symtab = (void*)(intptr_t) dynTab[j].d_un.d_val; // Rebased in Relocate
856 dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val;
860 pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val;
866 nbuckets = pBuckets[0];
867 // iSymCount = pBuckets[1];
868 pBuckets = &pBuckets[2];
869 pChains = &pBuckets[ nbuckets ];
872 iNameHash = ElfHashString(Name);
873 iNameHash %= nbuckets;
876 i = pBuckets[ iNameHash ];
877 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
878 *Ret = (void*)( (intptr_t)symtab[i].st_value + iBaseDiff );
879 if(Size) *Size = symtab[i].st_size;
880 DEBUGS("%s = %p", Name, *Ret);
884 while(pChains[i] != STN_UNDEF)
887 if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) {
888 *Ret = (void*)((intptr_t)symtab[i].st_value + iBaseDiff);
889 if(Size) *Size = symtab[i].st_size;
890 DEBUGS("%s = %p", Name, *Ret);
900 uint32_t ElfHashString(const char *name)
905 h = (h << 4) + *(uint8_t*)name++;
906 if( (g = h & 0xf0000000) )