From d8d31a4ec9a28eb8de493146ce75e8238e8e13b1 Mon Sep 17 00:00:00 2001 From: "John Hodge (sonata)" Date: Mon, 3 Nov 2014 12:41:33 +0800 Subject: [PATCH] Usermode/ld-acess - Overhaul cleanup of ELF loader --- KernelLand/Kernel/bin/elf.c | 72 ++- Usermode/Libraries/ld-acess.so_src/Makefile | 1 + Usermode/Libraries/ld-acess.so_src/elf.c | 564 +++--------------- Usermode/Libraries/ld-acess.so_src/elf32.h | 43 +- Usermode/Libraries/ld-acess.so_src/elf64.h | 4 +- Usermode/Libraries/ld-acess.so_src/elf_impl.c | 506 ++++++++++++++++ Usermode/Libraries/ld-acess.so_src/loadlib.c | 2 +- 7 files changed, 653 insertions(+), 539 deletions(-) create mode 100644 Usermode/Libraries/ld-acess.so_src/elf_impl.c diff --git a/KernelLand/Kernel/bin/elf.c b/KernelLand/Kernel/bin/elf.c index 7998d86c..37172cf9 100644 --- a/KernelLand/Kernel/bin/elf.c +++ b/KernelLand/Kernel/bin/elf.c @@ -205,15 +205,14 @@ tBinary *Elf_Load32(int FD, Elf32_Ehdr *Header) { tBinary *ret; Elf32_Phdr *phtab; - int i, j; - int iLoadCount; + int j; ENTER("xFD", FD); // Check architecture with current CPU // - TODO: Support kernel level emulation #if ARCH_IS_x86 - if( Header->machine != EM_386 ) + if( Header->e_machine != EM_386 ) { Log_Warning("ELF", "Unknown architecure on ELF-32"); LEAVE_RET('n'); @@ -222,7 +221,7 @@ tBinary *Elf_Load32(int FD, Elf32_Ehdr *Header) #endif // Check for a program header - if(Header->phoff == 0) { + if(Header->e_phoff == 0) { #if DEBUG_WARN Log_Warning("ELF", "File does not contain a program header (phoff == 0)"); #endif @@ -231,25 +230,25 @@ tBinary *Elf_Load32(int FD, Elf32_Ehdr *Header) } // Read Program Header Table - phtab = malloc( sizeof(Elf32_Phdr) * Header->phentcount ); + phtab = malloc( sizeof(Elf32_Phdr) * Header->e_phnum ); if( !phtab ) { LEAVE('n'); return NULL; } - LOG("hdr.phoff = 0x%08x", Header->phoff); - VFS_Seek(FD, Header->phoff, SEEK_SET); - VFS_Read(FD, sizeof(Elf32_Phdr)*Header->phentcount, phtab); + LOG("hdr.phoff = 0x%08x", Header->e_phoff); + VFS_Seek(FD, Header->e_phoff, SEEK_SET); + VFS_Read(FD, sizeof(Elf32_Phdr)*Header->e_phnum, phtab); // Count Pages - iLoadCount = 0; - LOG("Header->phentcount = %i", Header->phentcount); - for( i = 0; i < Header->phentcount; i++ ) + unsigned iLoadCount = 0; + LOG("Header->phentcount = %i", Header->e_phnum); + for( int i = 0; i < Header->e_phnum; i++ ) { // Ignore Non-LOAD types - if(phtab[i].Type != PT_LOAD) + if(phtab[i].p_type != PT_LOAD) continue; iLoadCount ++; - LOG("phtab[%i] = {VAddr:0x%x, MemSize:0x%x}", i, phtab[i].VAddr, phtab[i].MemSize); + LOG("phtab[%i] = {VAddr:0x%x, MemSize:0x%x}", i, phtab[i].p_vaddr, phtab[i].p_memsz); } LOG("iLoadCount = %i", iLoadCount); @@ -257,56 +256,55 @@ tBinary *Elf_Load32(int FD, Elf32_Ehdr *Header) // Allocate Information Structure ret = malloc( sizeof(tBinary) + sizeof(tBinarySection)*iLoadCount ); // Fill Info Struct - ret->Entry = Header->entrypoint; + ret->Entry = Header->e_entry; ret->Base = -1; // Set Base to maximum value ret->NumSections = iLoadCount; ret->Interpreter = NULL; // Load Pages j = 0; - for( i = 0; i < Header->phentcount; i++ ) + for( int i = 0; i < Header->e_phnum; i++ ) { //LOG("phtab[%i].Type = 0x%x", i, phtab[i].Type); LOG("phtab[%i] = {", i); - LOG(" .Type = 0x%08x", phtab[i].Type); - LOG(" .Offset = 0x%08x", phtab[i].Offset); - LOG(" .VAddr = 0x%08x", phtab[i].VAddr); - LOG(" .PAddr = 0x%08x", phtab[i].PAddr); - LOG(" .FileSize = 0x%08x", phtab[i].FileSize); - LOG(" .MemSize = 0x%08x", phtab[i].MemSize); - LOG(" .Flags = 0x%08x", phtab[i].Flags); - LOG(" .Align = 0x%08x", phtab[i].Align); + LOG(" .Type = 0x%08x", phtab[i].p_type); + LOG(" .Offset = 0x%08x", phtab[i].p_offset); + LOG(" .VAddr = 0x%08x", phtab[i].p_vaddr); + LOG(" .PAddr = 0x%08x", phtab[i].p_paddr); + LOG(" .FileSize = 0x%08x", phtab[i].p_filesz); + LOG(" .MemSize = 0x%08x", phtab[i].p_memsz); + LOG(" .Flags = 0x%08x", phtab[i].p_flags); + LOG(" .Align = 0x%08x", phtab[i].p_align); LOG(" }"); // Get Interpreter Name - if( phtab[i].Type == PT_INTERP ) + if( phtab[i].p_type == PT_INTERP ) { - char *tmp; if(ret->Interpreter) continue; - tmp = malloc(phtab[i].FileSize); - VFS_Seek(FD, phtab[i].Offset, 1); - VFS_Read(FD, phtab[i].FileSize, tmp); + char* tmp = malloc(phtab[i].p_filesz); + VFS_Seek(FD, phtab[i].p_offset, 1); + VFS_Read(FD, phtab[i].p_filesz, tmp); ret->Interpreter = Binary_RegInterp(tmp); LOG("Interpreter '%s'", tmp); free(tmp); continue; } // Ignore non-LOAD types - if(phtab[i].Type != PT_LOAD) continue; + if(phtab[i].p_type != PT_LOAD) continue; // Find Base - if(phtab[i].VAddr < ret->Base) ret->Base = phtab[i].VAddr; + if(phtab[i].p_vaddr < ret->Base) ret->Base = phtab[i].p_vaddr; LOG("phtab[%i] = {VAddr:0x%x,Offset:0x%x,FileSize:0x%x}", - i, phtab[i].VAddr, phtab[i].Offset, phtab[i].FileSize); + i, phtab[i].p_vaddr, phtab[i].p_offset, phtab[i].p_filesz); - ret->LoadSections[j].Offset = phtab[i].Offset; - ret->LoadSections[j].FileSize = phtab[i].FileSize; - ret->LoadSections[j].Virtual = phtab[i].VAddr; - ret->LoadSections[j].MemSize = phtab[i].MemSize; + ret->LoadSections[j].Offset = phtab[i].p_offset; + ret->LoadSections[j].FileSize = phtab[i].p_filesz; + ret->LoadSections[j].Virtual = phtab[i].p_vaddr; + ret->LoadSections[j].MemSize = phtab[i].p_memsz; ret->LoadSections[j].Flags = 0; - if( !(phtab[i].Flags & PF_W) ) + if( !(phtab[i].p_flags & PF_W) ) ret->LoadSections[j].Flags |= BIN_SECTFLAG_RO; - if( phtab[i].Flags & PF_X ) + if( phtab[i].p_flags & PF_X ) ret->LoadSections[j].Flags |= BIN_SECTFLAG_EXEC; j ++; } diff --git a/Usermode/Libraries/ld-acess.so_src/Makefile b/Usermode/Libraries/ld-acess.so_src/Makefile index a588f759..78aac4bd 100644 --- a/Usermode/Libraries/ld-acess.so_src/Makefile +++ b/Usermode/Libraries/ld-acess.so_src/Makefile @@ -11,6 +11,7 @@ EXTRABIN := libld-acess.so EXTRACLEAN = $(_OBJPREFIX)_stublib.o INCFILES := sys/sys.h +#CPPFLAGS += -D DISABLE_ELF64 CFLAGS = -g -Wall -fno-builtin -fno-stack-protector -fPIC -std=c99 -ffreestanding # -fno-leading-underscore CFLAGS += $(CPPFLAGS) diff --git a/Usermode/Libraries/ld-acess.so_src/elf.c b/Usermode/Libraries/ld-acess.so_src/elf.c index 1e31f771..fa2e3f44 100644 --- a/Usermode/Libraries/ld-acess.so_src/elf.c +++ b/Usermode/Libraries/ld-acess.so_src/elf.c @@ -17,6 +17,7 @@ #include "common.h" #include +#include #ifndef assert # include #endif @@ -38,38 +39,24 @@ # define SUPPORT_ELF64 #endif -typedef struct -{ - void *Base; - intptr_t iBaseDiff; - const char *strtab; - Elf32_Sym *symtab; -} tElfRelocInfo; - -typedef int tElf32RelocFcn(tElfRelocInfo *Info, uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int bRela); - // === CONSTANTS === #if DEBUG //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"}; //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"}; #endif +#ifdef SUPPORT_ELF64 +#endif + // === PROTOTYPES === void *ElfRelocate(void *Base, char **envp, const char *Filename); int ElfGetSymbol(void *Base, const char *Name, void **Ret, size_t *Size); -void *Elf32Relocate(void *Base, char **envp, const char *Filename); - int Elf32GetSymbolVars(void *Base, Elf32_Sym** symtab, Elf32_Word** pBuckets, const char **dynstrtab, uintptr_t* piBaseDiff); - int Elf32GetSymbolInfo(void *Base, const char *Name, void **Addr, size_t *Size, int* Section, int *Binding, int *Type); - int Elf32GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size); -tElf32RelocFcn elf_doRelocate_386; -tElf32RelocFcn elf_doRelocate_arm; -tElf32RelocFcn elf_doRelocate_unk; +void *Elf32_Relocate(void *Base, char **envp, const char *Filename); + int Elf32_GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size); #ifdef SUPPORT_ELF64 -int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend); -void *Elf64Relocate(void *Base, char **envp, const char *Filename); - int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size); +void *Elf64_Relocate(void *Base, char **envp, const char *Filename); + int Elf64_GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size); #endif - int Elf32GetSymbolReloc(tElfRelocInfo *Info, const Elf32_Sym *Symbol, void **Ret, size_t *Size); uint32_t ElfHashString(const char *name); // === CODE === @@ -84,10 +71,10 @@ void *ElfRelocate(void *Base, char **envp, const char *Filename) switch(hdr->e_ident[4]) { case ELFCLASS32: - return Elf32Relocate(Base, envp, Filename); + return Elf32_Relocate(Base, envp, Filename); #ifdef SUPPORT_ELF64 case ELFCLASS64: - return Elf64Relocate(Base, envp, Filename); + return Elf64_Relocate(Base, envp, Filename); #endif default: SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]); @@ -105,10 +92,10 @@ int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size) switch(hdr->e_ident[4]) { case ELFCLASS32: - return Elf32GetSymbol(Base, Name, ret, Size); + return Elf32_GetSymbol(Base, Name, ret, Size); #ifdef SUPPORT_ELF64 case ELFCLASS64: - return Elf64GetSymbol(Base, Name, ret, Size); + return Elf64_GetSymbol(Base, Name, ret, Size); #endif default: SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]); @@ -116,7 +103,17 @@ int ElfGetSymbol(void *Base, const char *Name, void **ret, size_t *Size) } } -int elf_doRelocate_386(tElfRelocInfo *Info, uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int bRela) +// -------------------------------------------------------------------- +// Elf32 support +// -------------------------------------------------------------------- +#define ELFTYPE Elf32 +#include "elf_impl.c" +#undef ELFTYPE + +Elf32_RelocFcn elf_doRelocate_386; +Elf32_RelocFcn elf_doRelocate_arm; + +int elf_doRelocate_386(const Elf32_RelocInfo *Info, Elf32_Word r_info, Elf32_Word* ptr, Elf32_Addr addend, bool bRela) { const Elf32_Sym *sym = &Info->symtab[ ELF32_R_SYM(r_info) ]; void *symval = (void*)(intptr_t)sym->st_value; @@ -180,7 +177,7 @@ int elf_doRelocate_386(tElfRelocInfo *Info, uint32_t r_info, uint32_t *ptr, Elf3 return 0; } -int elf_doRelocate_arm(tElfRelocInfo *Info, uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int bRela) +int elf_doRelocate_arm(const Elf32_RelocInfo *Info, Elf32_Word r_info, Elf32_Word* ptr, Elf32_Addr addend, bool bRela) { const Elf32_Sym *sym = &Info->symtab[ ELF32_R_SYM(r_info) ]; void *symval = (void*)(intptr_t)sym->st_value; @@ -227,490 +224,98 @@ int elf_doRelocate_arm(tElfRelocInfo *Info, uint32_t r_info, uint32_t *ptr, Elf3 return 0; } -int elf_doRelocate_unk(tElfRelocInfo *Info, uint32_t r_info, uint32_t *ptr, Elf32_Addr addend, int bRela) -{ - return 1; -} - -void *Elf32Relocate(void *Base, char **envp, const char *Filename) +Elf32_RelocFcn* Elf32_GetRelocFcn(unsigned Machine) { - const Elf32_Ehdr *hdr = Base; - char *libPath; - intptr_t iRealBase = -1; - Elf32_Rel *rel = NULL; - Elf32_Rela *rela = NULL; - void *plt = NULL; - int relSz=0, relEntSz=8; - int relaSz=0, relaEntSz=8; - int pltSz=0, pltType=0; - Elf32_Dyn *dynamicTab = NULL; // Dynamic Table Pointer - - TRACE("(Base=0x%x)", Base); - - // Check magic header - - - // Parse Program Header to get Dynamic Table - // - Determine the linked base of the executable - const Elf32_Phdr *phtab = (void*)( (uintptr_t)Base + hdr->phoff ); - const int iSegmentCount = hdr->phentcount; - for(int i = 0; i < iSegmentCount; i ++) + switch(Machine) { - switch(phtab[i].Type) - { - case PT_LOAD: - // Determine linked base address - if( iRealBase > phtab[i].VAddr) - iRealBase = phtab[i].VAddr; - break; - case PT_DYNAMIC: - // Find Dynamic Section - if(!dynamicTab) { - dynamicTab = (void *) (intptr_t) phtab[i].VAddr; - } - else { - WARNING("elf_relocate: Multiple PT_DYNAMIC segments"); - } - break; - } - } - - // Page Align real base - iRealBase &= ~0xFFF; - - // Adjust "Real" Base - const intptr_t iBaseDiff = (intptr_t)Base - iRealBase; - - TRACE("True Base = 0x%x, Compiled Base = 0x%x, Difference = 0x%x", Base, iRealBase, iBaseDiff); - - // Check if a PT_DYNAMIC segement was found - if(!dynamicTab) { - SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base); - return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff); - } - - // Allow writing to read-only segments, just in case they need to be relocated - // - Will be reversed at the end of the function - for( int i = 0; i < iSegmentCount; i ++ ) - { - if(phtab[i].Type == PT_LOAD && !(phtab[i].Flags & PF_W) ) { - uintptr_t addr = phtab[i].VAddr + iBaseDiff; - uintptr_t end = addr + phtab[i].MemSize; - for( ; addr < end; addr += PAGE_SIZE ) - _SysSetMemFlags(addr, 0, 1); // Unset RO - } - } - - // Adjust Dynamic Table - dynamicTab = (void *)( (intptr_t)dynamicTab + iBaseDiff ); - - // === Get Symbol table and String Table === - char *dynstrtab = NULL; // .dynamic String Table - Elf32_Sym *dynsymtab = NULL; - Elf32_Word *hashtable = NULL; - int iSymCount = 0; - for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++) - { - const Elf32_Dyn *dt = &dynamicTab[j]; - switch(dt->d_tag) - { - // --- Symbol Table --- - case DT_SYMTAB: - TRACE("DYNAMIC Symbol Table 0x%x (0x%x)", dt->d_val, dt->d_val + iBaseDiff); - dynsymtab = (void*)((intptr_t)dt->d_val + iBaseDiff); - break; - // --- String Table --- - case DT_STRTAB: - TRACE("DYNAMIC String Table 0x%x (0x%x)", dt->d_val, dt->d_val + iBaseDiff); - dynstrtab = (void*)((intptr_t)dt->d_val + iBaseDiff); - break; - // --- Hash Table -- - case DT_HASH: - TRACE("DYNAMIC Hash table %p (%p)", dt->d_val, dt->d_val + iBaseDiff); - hashtable = (void*)((intptr_t)dt->d_val + iBaseDiff); - iSymCount = hashtable[1]; - break; - } + case EM_386: return elf_doRelocate_386; + case EM_ARM: return elf_doRelocate_arm; + default: return NULL; } +} - if(dynsymtab == NULL) { - SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr); - return (void *)(intptr_t) (hdr->entrypoint + iBaseDiff); - } - - // Apply base offset to locally defined symbols - // - #0 is defined as ("" SHN_UNDEF), so skip it - for( int i = 1; i < iSymCount; i ++ ) - { - Elf32_Sym *sym = &dynsymtab[i]; - const char *name = dynstrtab + sym->st_name; - (void)name; - if( sym->st_shndx == SHN_UNDEF ) - { - TRACE("Sym %i'%s' deferred (SHN_UNDEF)", i, name); - } - else if( sym->st_shndx == SHN_ABS ) - { - // Leave as is - SysDebug("Sym %i'%s' untouched", i, name); - } - else - { - void *newval; - size_t newsize; - if( ELF32_ST_BIND(sym->st_info) != STB_WEAK ) - { - TRACE("Sym %i'%s' = %p (local)", i, name, sym->st_value + iBaseDiff); - sym->st_value += iBaseDiff; - } - // If GetSymbol doesn't return a strong/global symbol value - else if( GetSymbol(name, &newval, &newsize, Base) != 1 ) - { - TRACE("Sym %i'%s' = %p (Local weak)", i, name, sym->st_value + iBaseDiff); - sym->st_value += iBaseDiff; - } - else - { - TRACE("Sym %i'%s' = %p+0x%x (Extern weak)", i, name, newval, newsize); - sym->st_value = (uintptr_t)newval; - sym->st_size = newsize; - } - } - } - // === Add to loaded list (can be imported now) === - AddLoaded( Filename, Base ); +// -------------------------------------------------------------------- +// Elf64 support +// -------------------------------------------------------------------- +#ifdef SUPPORT_ELF64 - // === Parse Relocation Data === - TRACE("dynamicTab = 0x%x", dynamicTab); - for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++) - { - const Elf32_Dyn *dt = &dynamicTab[j]; - switch(dt->d_tag) - { - // --- Shared Library Name --- - case DT_SONAME: - TRACE(".so Name '%s'", dynstrtab + dt->d_val); - break; - // --- Needed Library --- - case DT_NEEDED: - //assert(dt->d_val <= sizeof_dynstrtab); - libPath = dynstrtab + dt->d_val; - TRACE(" Required Library '%s'", libPath); - if(LoadLibrary(libPath, NULL, envp) == 0) { - SysDebug("Unable to load required library '%s'", libPath); - return 0; - } - TRACE(" Lib loaded"); - break; - // --- PLT/GOT --- -// case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dt->d_val); break; - case DT_JMPREL: plt = (void*)(iBaseDiff + dt->d_val); break; - case DT_PLTREL: pltType = dt->d_val; break; - case DT_PLTRELSZ: pltSz = dt->d_val; break; - - // --- Relocation --- - case DT_REL: rel = (void*)(iBaseDiff + dt->d_val); break; - case DT_RELSZ: relSz = dt->d_val; break; - case DT_RELENT: relEntSz = dt->d_val; break; - case DT_RELA: rela = (void*)(iBaseDiff + dt->d_val); break; - case DT_RELASZ: relaSz = dt->d_val; break; - case DT_RELAENT: relaEntSz = dt->d_val; break; - - // --- Symbol Table --- - case DT_SYMTAB: - // --- Hash Table --- - case DT_HASH: - // --- String Table --- - case DT_STRTAB: - break; - - // --- Unknown --- - default: - if(dt->d_tag > DT_JMPREL) continue; - //DEBUGS(" elf_relocate: %i-%i = %s,0x%x", - // i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val); - break; - } - } - - // Resolve symbols (second pass) - // - #0 is defined as ("" SHN_UNDEF), so skip it - int fail = 0; - for( int i = 1; i < iSymCount; i ++ ) - { - Elf32_Sym *sym = &dynsymtab[i]; - const char *name = dynstrtab + sym->st_name; - if( sym->st_shndx == SHN_UNDEF ) - { - void *newval; - size_t newsize; - if( !GetSymbol(name, &newval, &newsize, Base) ) { - if( ELF32_ST_BIND(sym->st_info) != STB_WEAK ) { - // Not a weak binding, set fail and move on - WARNING("Elf32Relocate: Can't find required symbol '%s' for '%s'", - name, Filename); - fail = 1; - continue ; - } - // Leave the symbol value as-is - } - else { - TRACE("Sym %i'%s' bound to %p+0x%x", i, name, newval, newsize); - sym->st_value = (intptr_t)newval; - sym->st_size = newsize; - } - } - else if( sym->st_shndx == SHN_ABS ) - { - // Leave as is - } - else - { - // Handled previously - // TODO: What about weak locally-defined symbols? - //assert( ELF32_ST_BIND(sym->st_info) != STB_WEAK ); - } - } - if( fail ) { - WARNING("Relocation of '%s' failed", Filename); - return NULL; - } - - TRACE("Beginning Relocation on '%s'", Filename); +#define ELFTYPE Elf64 +#include "elf_impl.c" +#undef ELFTYPE +Elf64_RelocFcn elf_doRelocate_x86_64; - tElf32RelocFcn *do_relocate; - switch(hdr->machine) +int elf_doRelocate_x86_64(const Elf64_RelocInfo *Info, Elf64_Xword r_info, Elf64_Xword* ptr, Elf64_Addr addend, bool bRela) +{ + const Elf64_Sym *sym = &Info->symtab[ ELF64_R_SYM(r_info) ]; + void *symval = (void*)(intptr_t)sym->st_value; + size_t size = sym->st_size; + TRACE("%i '%s'", ELF64_R_TYPE(r_info), Info->strtab + sym->st_name); + switch( ELF64_R_TYPE(r_info) ) { - case EM_386: - do_relocate = elf_doRelocate_386; + case R_X86_64_NONE: break; - case EM_ARM: - do_relocate = elf_doRelocate_arm; + case R_X86_64_64: + TRACE("R_X86_64_64 *0x%x = %p + 0x%x", ptr, symval, addend); + *ptr = (intptr_t)symval + addend; break; - default: - SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine); - do_relocate = elf_doRelocate_unk; - fail = 1; + // Absolute Value of a symbol (S) + case R_X86_64_GLOB_DAT: + TRACE("R_X86_64_GLOB_DAT *0x%x = %p", ptr, symval); if(0) + case R_X86_64_JUMP_SLOT: + TRACE("R_X86_64_JUMP_SLOT *0x%x = %p", ptr, symval); + *ptr = (intptr_t)symval; break; - } - - TRACE("do_relocate = %p (%p or %p)", do_relocate, &elf_doRelocate_386, &elf_doRelocate_arm); - #define _doRelocate(r_info, ptr, bRela, addend) \ - do_relocate(&reloc_info, r_info, ptr, addend, bRela); - - tElfRelocInfo reloc_info = { - .Base = Base, - .iBaseDiff = iBaseDiff, - .strtab = dynstrtab, - .symtab = dynsymtab - }; + // Base Address (B+A) + case R_X86_64_RELATIVE: + TRACE("R_X86_64_RELATIVE *0x%x = 0x%x + 0x%x", ptr, Info->iBaseDiff, addend); + *ptr = Info->iBaseDiff + addend; + break; - // Parse Relocation Entries - if(rel && relSz) - { - Elf32_Word *ptr; - TRACE("rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz); - int max = relSz / relEntSz; - for( int i = 0; i < max; i++ ) - { - ptr = (void*)(iBaseDiff + rel[i].r_offset); - fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr); - } - } - // Parse Relocation Entries - if(rela && relaSz) - { - Elf32_Word *ptr; - TRACE("rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz); - int count = relaSz / relaEntSz; - for( int i = 0; i < count; i++ ) - { - ptr = (void*)(iBaseDiff + rela[i].r_offset); - fail |= _doRelocate(rel[i].r_info, ptr, 1, rela[i].r_addend); - } - } - - // === Process PLT (Procedure Linkage Table) === - if(plt && pltSz) - { - Elf32_Word *ptr; - TRACE("Relocate PLT, plt=0x%x", plt); - if(pltType == DT_REL) + case R_X86_64_COPY: { + void *old_symval = symval; + GetSymbol(Info->strtab + sym->st_name, &symval, &size, Info->Base); + if( symval == old_symval ) { - Elf32_Rel *pltRel = plt; - int count = pltSz / sizeof(Elf32_Rel); - TRACE("PLT Reloc Type = Rel, %i entries", count); - for(int i = 0; i < count; i ++) + if( ELF64_ST_BIND(sym->st_info) != STB_WEAK ) { - ptr = (void*)(iBaseDiff + pltRel[i].r_offset); - fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr); + WARNING("sym={val:%p,size:0x%x,info:0x%x,other:0x%x,shndx:%i}", + sym->st_value, sym->st_size, sym->st_info, sym->st_other, sym->st_shndx); + WARNING("Can't find required external symbol '%s' for R_X86_64_COPY", Info->strtab + sym->st_name); + return 1; } + // Don't bother doing the memcpy + TRACE("R_X86_64_COPY (%p, %p, %i)", ptr, symval, size); } else { - Elf32_Rela *pltRela = plt; - int count = pltSz / sizeof(Elf32_Rela); - TRACE("PLT Reloc Type = Rela, %i entries", count); - for(int i=0;ientrypoint + iBaseDiff, __builtin_return_address(0)); - return (void*)(intptr_t)( hdr->entrypoint + iBaseDiff ); + return 0; } -int Elf32GetSymbolVars(void *Base, Elf32_Sym** symtab, Elf32_Word** pBuckets, const char **dynstrtab, uintptr_t* piBaseDiff) +Elf64_RelocFcn* Elf64_GetRelocFcn(unsigned Machine) { - Elf32_Dyn *dynTab = NULL; - uintptr_t iBaseDiff = -1; - Elf32_Ehdr *hdr = Base; - Elf32_Phdr *phtab = (void*)( (uintptr_t)Base + hdr->phoff ); - for( int i = 0; i < hdr->phentcount; i ++ ) - { - if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr) - iBaseDiff = phtab[i].VAddr; - if( phtab[i].Type == PT_DYNAMIC ) { - dynTab = (void*)(intptr_t)phtab[i].VAddr; - } - } - if( !dynTab ) { - SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base); - return 1; - } - iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff - dynTab = (void*)( (intptr_t)dynTab + iBaseDiff ); - for( int i = 0; dynTab[i].d_tag != DT_NULL; i++) - { - switch(dynTab[i].d_tag) - { - // --- Symbol Table --- - case DT_SYMTAB: - *symtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); // Rebased in Relocate - break; - case DT_STRTAB: - *dynstrtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); - break; - // --- Hash Table -- - case DT_HASH: - *pBuckets = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); - break; - } - } - - if( !*symtab ) { - SysDebug("ERRO - No DT_SYMTAB in %p", Base); - return 1; - } - if( !*pBuckets ) { - SysDebug("ERRO - No DT_HASH in %p", Base); - return 1; - } - if( !*dynstrtab ) { - SysDebug("ERRO - No DT_STRTAB in %p", Base); - return 1; - } - - // ... ok... maybe they haven't been relocated - if( (uintptr_t)*symtab < (uintptr_t)Base ) + switch(Machine) { - SysDebug("Executable not yet relocated (symtab,pBuckets,dynstrtab = %p,%p,%p + 0x%x)", - *symtab,*pBuckets,*dynstrtab, iBaseDiff); - *symtab = (void*)( (uintptr_t)*symtab + iBaseDiff ); - *pBuckets = (void*)( (uintptr_t)*pBuckets + iBaseDiff ); - *dynstrtab = (void*)( (uintptr_t)*dynstrtab + iBaseDiff ); + case EM_X86_64: return elf_doRelocate_x86_64; + default: return NULL; } - *piBaseDiff = iBaseDiff; - return 0; } -int Elf32GetSymbolInfo(void *Base, const char *Name, void **Addr, size_t *Size, int* Section, int *Binding, int *Type) -{ - // Locate the tables - uintptr_t iBaseDiff = -1; - Elf32_Sym *symtab = NULL; - Elf32_Word *pBuckets = NULL; - const char *dynstrtab = NULL; - if( Elf32GetSymbolVars(Base, &symtab, &pBuckets, &dynstrtab, &iBaseDiff) ) - return 1; - - int nbuckets = pBuckets[0]; -// int iSymCount = pBuckets[1]; - pBuckets = &pBuckets[2]; - Elf32_Word* pChains = &pBuckets[ nbuckets ]; - assert(pChains); - - // Get hash - int iNameHash = ElfHashString(Name); - iNameHash %= nbuckets; - - // Walk Chain - int idx = pBuckets[ iNameHash ]; - do { - const Elf32_Sym *sym = &symtab[idx]; - assert(sym); - if( strcmp(dynstrtab + sym->st_name, Name) == 0 ) - { - TRACE("*sym = {value:0x%x,size:0x%x,info:0x%x,other:0x%x,shndx:%i}", - sym->st_value, sym->st_size, sym->st_info, - sym->st_other, sym->st_shndx); - if(Addr) *Addr = (void*)(intptr_t)( sym->st_value ); - if(Size) *Size = sym->st_size; - if(Binding) *Binding = ELF32_ST_BIND(sym->st_info); - if(Type) *Type = ELF32_ST_TYPE(sym->st_info); - if(Section) *Section = sym->st_shndx; - return 0; - } - } while( (idx = pChains[idx]) != STN_UNDEF && idx != pBuckets[iNameHash] ); - - TRACE("No symbol"); - return 1; -} +#endif // SUPPORT_ELF64 -int Elf32GetSymbol(void *Base, const char *Name, void **ret, size_t *Size) -{ - int section, binding; - TRACE("Elf32GetSymbol(%p,%s,...)", Base, Name); - if( Elf32GetSymbolInfo(Base, Name, ret, Size, §ion, &binding, NULL) ) - return 0; - if( section == SHN_UNDEF ) { - TRACE("Elf32GetSymbol: Undefined %p", *ret, (Size?*Size:0), section); - return 0; - } - if( binding == STB_WEAK ) { - TRACE("Elf32GetSymbol: Weak, return %p+0x%x,section=%i", *ret, (Size?*Size:0), section); - return 2; - } - TRACE("Elf32GetSymbol: Found %p+0x%x,section=%i", *ret, (Size?*Size:0), section); - return 1; -} #ifdef SUPPORT_ELF64 +#if 0 typedef int (*t_elf64_doreloc)(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend); int _Elf64DoReloc_X86_64(void *Base, const char *strtab, Elf64_Sym *symtab, Elf64_Xword r_info, void *ptr, Elf64_Sxword addend) @@ -1046,6 +651,7 @@ int Elf64GetSymbol(void *Base, const char *Name, void **Ret, size_t *Size) return 0; } #endif +#endif uint32_t ElfHashString(const char *name) { diff --git a/Usermode/Libraries/ld-acess.so_src/elf32.h b/Usermode/Libraries/ld-acess.so_src/elf32.h index bb15f822..40c801c9 100644 --- a/Usermode/Libraries/ld-acess.so_src/elf32.h +++ b/Usermode/Libraries/ld-acess.so_src/elf32.h @@ -12,6 +12,7 @@ typedef uint16_t Elf32_Half; typedef uint32_t Elf32_Addr; typedef uint32_t Elf32_Off; typedef uint32_t Elf32_Word; +typedef uint32_t Elf32_Xword; // < not strictly correct... but meh typedef int32_t Elf32_Sword; #define ELFCLASS32 1 @@ -26,19 +27,19 @@ typedef int32_t Elf32_Sword; */ struct sElf32_Ehdr { uint8_t e_ident[16]; //!< Identifier Bytes - Elf32_Half filetype; //!< File Type - Elf32_Half machine; //!< Machine / Arch - Elf32_Word version; //!< Version (File?) - Elf32_Addr entrypoint; //!< Entry Point - Elf32_Off phoff; //!< Program Header Offset - Elf32_Word shoff; //!< Section Header Offset - Elf32_Word flags; //!< Flags - Elf32_Half headersize; //!< Header Size - Elf32_Half phentsize; //!< Program Header Entry Size - Elf32_Half phentcount; //!< Program Header Entry Count - Elf32_Half shentsize; //!< Section Header Entry Size - Elf32_Half shentcount; //!< Section Header Entry Count - Elf32_Half shstrindex; //!< Section Header String Table Index + Elf32_Half e_filetype; //!< File Type + Elf32_Half e_machine; //!< Machine / Arch + Elf32_Word e_version; //!< Version (File?) + Elf32_Addr e_entry; //!< Entry Point + Elf32_Off e_phoff; //!< Program Header Offset + Elf32_Word e_shoff; //!< Section Header Offset + Elf32_Word e_flags; //!< Flags + Elf32_Half e_headersize; //!< Header Size + Elf32_Half e_phentsize; //!< Program Header Entry Size + Elf32_Half e_phnum; //!< Program Header Entry Count + Elf32_Half e_shentsize; //!< Section Header Entry Size + Elf32_Half e_shentcount; //!< Section Header Entry Count + Elf32_Half e_shstrindex; //!< Section Header String Table Index }; /** @@ -147,14 +148,14 @@ enum { #define PF_R 4 struct sElf32_Phdr { - Elf32_Word Type; - Elf32_Off Offset; - Elf32_Addr VAddr; - Elf32_Addr PAddr; - Elf32_Word FileSize; - Elf32_Word MemSize; - Elf32_Word Flags; - Elf32_Word Align; + Elf32_Word p_type; + Elf32_Off p_offset; + Elf32_Addr p_vaddr; + Elf32_Addr p_paddr; + Elf32_Word p_filesz; + Elf32_Word p_memsz; + Elf32_Word p_flags; + Elf32_Word p_align; }; struct elf32_rel_s { diff --git a/Usermode/Libraries/ld-acess.so_src/elf64.h b/Usermode/Libraries/ld-acess.so_src/elf64.h index fb39782a..9d04e8af 100644 --- a/Usermode/Libraries/ld-acess.so_src/elf64.h +++ b/Usermode/Libraries/ld-acess.so_src/elf64.h @@ -69,7 +69,7 @@ typedef struct union { Elf64_Xword d_val; Elf64_Addr d_ptr; - } d_un; + };// d_un; } Elf64_Dyn; typedef struct @@ -97,6 +97,8 @@ typedef struct #define ELF64_R_SYM(info) ((info) >> 32) #define ELF64_R_TYPE(info) ((info) & 0xFFFFFFFF) +#define ELF64_ST_BIND(i) ((i)>>4) +#define ELF64_ST_TYPE(i) ((i)&0xF) enum eElf64_RelocTypes_x86_64 { diff --git a/Usermode/Libraries/ld-acess.so_src/elf_impl.c b/Usermode/Libraries/ld-acess.so_src/elf_impl.c new file mode 100644 index 00000000..a89a26f6 --- /dev/null +++ b/Usermode/Libraries/ld-acess.so_src/elf_impl.c @@ -0,0 +1,506 @@ + +#ifndef ELFTYPE +# error "ELFTYPE must be defined to either ELf32 or Elf64 to use this file" +#endif + +#define __PREF(t,s) t##_##s +#define _PREF(t,s) __PREF(t,s) +#define PREF(sym) _PREF(ELFTYPE,sym) + +typedef struct +{ + void *Base; + intptr_t iBaseDiff; + const char *strtab; + const PREF(Sym) *symtab; +} PREF(RelocInfo); + +typedef int PREF(RelocFcn)(const PREF(RelocInfo)* Info, PREF(Xword) t_info, PREF(Xword)* ptr, PREF(Addr) addend, bool bRela); + +// - Extern +static PREF(RelocFcn)* PREF(GetRelocFcn)(unsigned Machine); +// - Local +static PREF(RelocFcn) PREF(doRelocate_unk); +static void PREF(int_GetBaseDyntab)(void* Base, const PREF(Phdr)* phtab, unsigned phentcount, intptr_t* iBaseDiff_p, PREF(Dyn)** dynamicTab_p); +static int PREF(GetSymbolVars)(void *Base, const PREF(Sym)** symtab, const PREF(Word)** pBuckets, const char **dynstrtab, uintptr_t* piBaseDiff); +static int PREF(GetSymbolInfo)(void *Base, const char *Name, void **Addr, size_t *Size, int* Section, int *Binding, int *Type); + +// - Relocate +void *PREF(Relocate)(void *Base, char **envp, const char *Filename) +{ + TRACE("(Base=0x%x)", Base); + const PREF(Ehdr) *hdr = Base; + + // Check magic header + // TODO: Validate header? + + + // Parse Program Header to get Dynamic Table + // - Determine the linked base of the executable + const PREF(Phdr) *phtab = (void*)( (uintptr_t)Base + hdr->e_phoff ); + + intptr_t iBaseDiff = 0; + PREF(Dyn)* dynamicTab = NULL; + + PREF(int_GetBaseDyntab)(Base, phtab, hdr->e_phnum, &iBaseDiff, &dynamicTab); + + // Check if a PT_DYNAMIC segement was found + if(!dynamicTab) + { + SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base); + return (void *)(intptr_t)(hdr->e_entry + iBaseDiff); + } + + // Allow writing to read-only segments, just in case they need to be relocated + // - Will be reversed at the end of the function + for( unsigned i = 0; i < hdr->e_phnum; i ++ ) + { + if(phtab[i].p_type == PT_LOAD && !(phtab[i].p_flags & PF_W) ) + { + uintptr_t addr = phtab[i].p_vaddr + iBaseDiff; + uintptr_t end = addr + phtab[i].p_memsz; + for( ; addr < end; addr += PAGE_SIZE ) + _SysSetMemFlags(addr, 0, 1); // Unset RO + } + } + + // === Get Symbol table and String Table === + char *dynstrtab = NULL; // .dynamic String Table + PREF(Sym) *dynsymtab = NULL; + PREF(Word) *hashtable = NULL; + unsigned iSymCount = 0; + for( unsigned j = 0; dynamicTab[j].d_tag != DT_NULL; j++) + { + const PREF(Dyn) *dt = &dynamicTab[j]; + switch(dt->d_tag) + { + // --- Symbol Table --- + case DT_SYMTAB: + TRACE("DYNAMIC Symbol Table 0x%x (0x%x)", dt->d_val, dt->d_val + iBaseDiff); + dynsymtab = (void*)((intptr_t)dt->d_val + iBaseDiff); + break; + // --- String Table --- + case DT_STRTAB: + TRACE("DYNAMIC String Table 0x%x (0x%x)", dt->d_val, dt->d_val + iBaseDiff); + dynstrtab = (void*)((intptr_t)dt->d_val + iBaseDiff); + break; + // --- Hash Table -- + case DT_HASH: + TRACE("DYNAMIC Hash table %p (%p)", dt->d_val, dt->d_val + iBaseDiff); + hashtable = (void*)((intptr_t)dt->d_val + iBaseDiff); + iSymCount = hashtable[1]; + break; + } + } + + if(dynsymtab == NULL) { + SysDebug("ld-acess.so - WARNING: No Dynamic Symbol table in %p, returning", hdr); + return (void *)(intptr_t) (hdr->e_entry + iBaseDiff); + } + + // Apply base offset to locally defined symbols + // - #0 is defined as ("" SHN_UNDEF), so skip it + for( unsigned i = 1; i < iSymCount; i ++ ) + { + PREF(Sym) *sym = &dynsymtab[i]; + const char *name = dynstrtab + sym->st_name; + (void)name; + if( sym->st_shndx == SHN_UNDEF ) + { + TRACE("Sym %i'%s' deferred (SHN_UNDEF)", i, name); + } + else if( sym->st_shndx == SHN_ABS ) + { + // Leave as is + TRACE("Sym %i'%s' untouched", i, name); + } + else + { + void *newval; + size_t newsize; + if( ELF32_ST_BIND(sym->st_info) != STB_WEAK ) + { + TRACE("Sym %i'%s' = %p (local)", i, name, sym->st_value + iBaseDiff); + sym->st_value += iBaseDiff; + } + // If GetSymbol doesn't return a strong/global symbol value + else if( GetSymbol(name, &newval, &newsize, Base) != 1 ) + { + TRACE("Sym %i'%s' = %p (Local weak)", i, name, sym->st_value + iBaseDiff); + sym->st_value += iBaseDiff; + } + else + { + TRACE("Sym %i'%s' = %p+0x%x (Extern weak)", i, name, newval, newsize); + sym->st_value = (uintptr_t)newval; + sym->st_size = newsize; + } + } + } + + // === Add to loaded list (can be imported now) === + AddLoaded( Filename, Base ); + + // === Parse Relocation Data === + PREF(Rel) *rel = NULL; + PREF(Rela) *rela = NULL; + void *plt = NULL; + int relSz=0, relEntSz=8; + int relaSz=0, relaEntSz=8; + int pltSz=0, pltType=0; + TRACE("dynamicTab = 0x%x", dynamicTab); + for( int j = 0; dynamicTab[j].d_tag != DT_NULL; j++) + { + const PREF(Dyn) *dt = &dynamicTab[j]; + switch(dt->d_tag) + { + // --- Shared Library Name --- + case DT_SONAME: + TRACE(".so Name '%s'", dynstrtab + dt->d_val); + break; + // --- Needed Library --- + case DT_NEEDED: { + //assert(dt->d_val < sizeof_dynstrtab); // Disabled, no sizeof_dynstrtab + const char *libPath = dynstrtab + dt->d_val; + TRACE(" Required Library '%s'", libPath); + if(LoadLibrary(libPath, NULL, envp) == 0) { + SysDebug("Unable to load required library '%s'", libPath); + return 0; + } + TRACE(" Lib loaded"); + break; } + // --- PLT/GOT --- +// case DT_PLTGOT: pltgot = (void*)(iBaseDiff + dt->d_val); break; + case DT_JMPREL: plt = (void*)(iBaseDiff + dt->d_val); break; + case DT_PLTREL: pltType = dt->d_val; break; + case DT_PLTRELSZ: pltSz = dt->d_val; break; + + // --- Relocation --- + case DT_REL: rel = (void*)(iBaseDiff + dt->d_val); break; + case DT_RELSZ: relSz = dt->d_val; break; + case DT_RELENT: relEntSz = dt->d_val; break; + case DT_RELA: rela = (void*)(iBaseDiff + dt->d_val); break; + case DT_RELASZ: relaSz = dt->d_val; break; + case DT_RELAENT: relaEntSz = dt->d_val; break; + + // --- Symbol Table --- + case DT_SYMTAB: + // --- Hash Table --- + case DT_HASH: + // --- String Table --- + case DT_STRTAB: + break; + + // --- Unknown --- + default: + if(dt->d_tag > DT_JMPREL) continue; + //DEBUGS(" elf_relocate: %i-%i = %s,0x%x", + // i,j, csaDT_NAMES[dynamicTab[j].d_tag],dynamicTab[j].d_val); + break; + } + } + + // Resolve symbols (second pass) + // - #0 is defined as ("" SHN_UNDEF), so skip it + int fail = 0; + for( int i = 1; i < iSymCount; i ++ ) + { + PREF(Sym) *sym = &dynsymtab[i]; + const char *name = dynstrtab + sym->st_name; + if( sym->st_shndx == SHN_UNDEF ) + { + void *newval; + size_t newsize; + if( !GetSymbol(name, &newval, &newsize, Base) ) { + if( ELF32_ST_BIND(sym->st_info) != STB_WEAK ) { + // Not a weak binding, set fail and move on + WARNING("%s: Can't find required symbol '%s' for '%s'", __func__, name, Filename); + fail = 1; + continue ; + } + // Leave the symbol value as-is + } + else { + TRACE("Sym %i'%s' bound to %p+0x%x", i, name, newval, newsize); + sym->st_value = (intptr_t)newval; + sym->st_size = newsize; + } + } + else if( sym->st_shndx == SHN_ABS ) + { + // Leave as is + } + else + { + // Handled previously + // TODO: What about weak locally-defined symbols? + //assert( ELF32_ST_BIND(sym->st_info) != STB_WEAK ); + } + } + if( fail ) { + WARNING("Relocation of '%s' failed", Filename); + return NULL; + } + + TRACE("Beginning Relocation on '%s'", Filename); + + + PREF(RelocFcn)* do_relocate = PREF(GetRelocFcn)(hdr->e_machine); + if( do_relocate == 0 ) + { + SysDebug("%s: Unknown machine type %i", __func__, hdr->e_machine); + do_relocate = PREF(doRelocate_unk); + fail = 1; + } + + TRACE("do_relocate = %p", do_relocate); + + #define _doRelocate(r_info, ptr, bRela, addend) \ + do_relocate(&reloc_info, r_info, ptr, addend, bRela); + + PREF(RelocInfo) reloc_info = { + .Base = Base, + .iBaseDiff = iBaseDiff, + .strtab = dynstrtab, + .symtab = dynsymtab + }; + + // Parse Relocation Entries + if(rel && relSz) + { + TRACE("rel=0x%x, relSz=0x%x, relEntSz=0x%x", rel, relSz, relEntSz); + int max = relSz / relEntSz; + for( int i = 0; i < max; i++ ) + { + PREF(Xword) *ptr = (void*)(iBaseDiff + rel[i].r_offset); + fail |= _doRelocate(rel[i].r_info, ptr, 0, *ptr); + } + } + // Parse Relocation Entries + if(rela && relaSz) + { + TRACE("rela=0x%x, relaSz=0x%x, relaEntSz=0x%x", rela, relaSz, relaEntSz); + int count = relaSz / relaEntSz; + for( int i = 0; i < count; i++ ) + { + void *ptr = (void*)(iBaseDiff + rela[i].r_offset); + fail |= _doRelocate(rela[i].r_info, ptr, 1, rela[i].r_addend); + } + } + + // === Process PLT (Procedure Linkage Table) === + if(plt && pltSz) + { + TRACE("Relocate PLT, plt=0x%x", plt); + if(pltType == DT_REL) + { + PREF(Rel) *pltRel = plt; + int count = pltSz / sizeof(*pltRel); + TRACE("PLT Reloc Type = Rel, %i entries", count); + for(int i = 0; i < count; i ++) + { + PREF(Xword) *ptr = (void*)(iBaseDiff + pltRel[i].r_offset); + fail |= _doRelocate(pltRel[i].r_info, ptr, 0, *ptr); + } + } + else + { + PREF(Rela) *pltRela = plt; + int count = pltSz / sizeof(*pltRela); + TRACE("PLT Reloc Type = Rela, %i entries", count); + for(int i=0;ie_phnum; i ++ ) + { + // If load and not writable + if(phtab[i].p_type == PT_LOAD && !(phtab[i].p_flags & PF_W) ) + { + uintptr_t addr = phtab[i].p_vaddr + iBaseDiff; + uintptr_t end = addr + phtab[i].p_memsz; + for( ; addr < end; addr += PAGE_SIZE ) + _SysSetMemFlags(addr, 1, 1); // Unset RO + } + } + + if( fail ) { + TRACE("ElfRelocate: Failure"); + return NULL; + } + + #undef _doRelocate + + TRACE("RETURN 0x%x to %p", hdr->e_entry + iBaseDiff, __builtin_return_address(0)); + return (void*)(intptr_t)( hdr->e_entry + iBaseDiff ); +} + +void PREF(int_GetBaseDyntab)(void* Base, const PREF(Phdr)* phtab, unsigned phentcount, intptr_t* iBaseDiff_p, PREF(Dyn)** dynamicTab_p) +{ + uintptr_t iRealBase = UINTPTR_MAX; + assert(dynamicTab_p); + + for(unsigned i = 0; i < phentcount; i ++) + { + switch(phtab[i].p_type) + { + case PT_LOAD: + // Determine linked base address + if( iRealBase > phtab[i].p_vaddr) + iRealBase = phtab[i].p_vaddr; + break; + case PT_DYNAMIC: + // Find Dynamic Section + if(!*dynamicTab_p) { + *dynamicTab_p = (void *) (intptr_t) phtab[i].p_vaddr; + } + else { + WARNING("elf_relocate: Multiple PT_DYNAMIC segments"); + } + break; + } + } + + // Page Align real base + iRealBase &= ~0xFFF; + + // Adjust "Real" Base + const intptr_t iBaseDiff = (intptr_t)Base - iRealBase; + *iBaseDiff_p = iBaseDiff; + + // Adjust Dynamic Table + if( *dynamicTab_p ) + { + *dynamicTab_p = (void *)( (intptr_t)*dynamicTab_p + iBaseDiff ); + } + + TRACE("True Base = 0x%x, Compiled Base = 0x%x, Difference = 0x%x", Base, iRealBase, *iBaseDiff_p); +} + +int PREF(doRelocate_unk)(const PREF(RelocInfo)* Info, PREF(Xword) r_info, PREF(Xword)* ptr, PREF(Addr) addend, bool bRela) +{ + return 1; +} + +int PREF(GetSymbolVars)(void *Base, const PREF(Sym)** symtab, const PREF(Word)** pBuckets, const char **dynstrtab, uintptr_t* piBaseDiff) +{ + const PREF(Ehdr)* hdr = Base; + PREF(Dyn)* dynTab = NULL; + intptr_t iBaseDiff = -1; + + PREF(int_GetBaseDyntab)(Base, (void*)( (uintptr_t)Base + hdr->e_phoff ), hdr->e_phnum, &iBaseDiff, &dynTab); + if( !dynTab ) { + SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base); + return 1; + } + + for( int i = 0; dynTab[i].d_tag != DT_NULL; i++) + { + switch(dynTab[i].d_tag) + { + // --- Symbol Table --- + case DT_SYMTAB: + *symtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); // Rebased in Relocate + break; + case DT_STRTAB: + *dynstrtab = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); + break; + // --- Hash Table -- + case DT_HASH: + *pBuckets = (void*)((intptr_t)dynTab[i].d_val + iBaseDiff); + break; + } + } + + if( !*symtab ) { + SysDebug("ERRO - No DT_SYMTAB in %p", Base); + return 1; + } + if( !*pBuckets ) { + SysDebug("ERRO - No DT_HASH in %p", Base); + return 1; + } + if( !*dynstrtab ) { + SysDebug("ERRO - No DT_STRTAB in %p", Base); + return 1; + } + + // ... ok... maybe they haven't been relocated + if( (uintptr_t)*symtab < (uintptr_t)Base ) + { + SysDebug("Executable not yet relocated (symtab,pBuckets,dynstrtab = %p,%p,%p + 0x%x)", + *symtab,*pBuckets,*dynstrtab, iBaseDiff); + *symtab = (void*)( (uintptr_t)*symtab + iBaseDiff ); + *pBuckets = (void*)( (uintptr_t)*pBuckets + iBaseDiff ); + *dynstrtab = (void*)( (uintptr_t)*dynstrtab + iBaseDiff ); + } + *piBaseDiff = iBaseDiff; + return 0; +} + +int PREF(GetSymbolInfo)(void *Base, const char *Name, void **Addr, size_t *Size, int* Section, int *Binding, int *Type) +{ + // Locate the tables + uintptr_t iBaseDiff = -1; + const PREF(Sym)* symtab = NULL; + const PREF(Word)* pBuckets = NULL; + const char *dynstrtab = NULL; + if( PREF(GetSymbolVars)(Base, &symtab, &pBuckets, &dynstrtab, &iBaseDiff) ) + return 1; + + unsigned nbuckets = pBuckets[0]; +// int iSymCount = pBuckets[1]; + pBuckets = &pBuckets[2]; + + const PREF(Word)* pChains = &pBuckets[ nbuckets ]; + assert(pChains); + + // Get hash + unsigned iNameHash = ElfHashString(Name); + iNameHash %= nbuckets; + + // Walk Chain + unsigned idx = pBuckets[ iNameHash ]; + do { + const PREF(Sym)* sym = &symtab[idx]; + assert(sym); + if( strcmp(dynstrtab + sym->st_name, Name) == 0 ) + { + TRACE("*sym = {value:0x%x,size:0x%x,info:0x%x,other:0x%x,shndx:%i}", + sym->st_value, sym->st_size, sym->st_info, + sym->st_other, sym->st_shndx); + if(Addr) *Addr = (void*)(intptr_t)( sym->st_value ); + if(Size) *Size = sym->st_size; + if(Binding) *Binding = ELF32_ST_BIND(sym->st_info); + if(Type) *Type = ELF32_ST_TYPE(sym->st_info); + if(Section) *Section = sym->st_shndx; + return 0; + } + } while( (idx = pChains[idx]) != STN_UNDEF && idx != pBuckets[iNameHash] ); + + TRACE("No symbol"); + return 1; +} + +int PREF(GetSymbol)(void *Base, const char *Name, void **ret, size_t *Size) +{ + int section, binding; + TRACE("%s(%p,%s,...)", __func__, Base, Name); + if( PREF(GetSymbolInfo)(Base, Name, ret, Size, §ion, &binding, NULL) ) + return 0; + if( section == SHN_UNDEF ) { + TRACE("%s: Undefined %p", __func__, *ret, (Size?*Size:0), section); + return 0; + } + if( binding == STB_WEAK ) { + TRACE("%s: Weak, return %p+0x%x,section=%i", __func__, *ret, (Size?*Size:0), section); + return 2; + } + TRACE("%s: Found %p+0x%x,section=%i", __func__, *ret, (Size?*Size:0), section); + return 1; +} diff --git a/Usermode/Libraries/ld-acess.so_src/loadlib.c b/Usermode/Libraries/ld-acess.so_src/loadlib.c index 1c750a8f..31dcbd8a 100644 --- a/Usermode/Libraries/ld-acess.so_src/loadlib.c +++ b/Usermode/Libraries/ld-acess.so_src/loadlib.c @@ -65,7 +65,7 @@ void CallQueuedEntrypoints(char **EnvP) { giNumQueuedEntrypoints --; const struct sQueuedEntry *qe = &gaQueuedEntrypoints[giNumQueuedEntrypoints]; - //_SysDebug("Calling EP for %p", qe->Base); + DEBUGS("Calling EP %p for %p", qe->Entry, qe->Base); qe->Entry(qe->Base, 0, NULL, EnvP); } } -- 2.20.1