X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Usermode%2FLibraries%2Fld-acess.so_src%2Felf.c;h=cba670e79e72fba0fec0c78128ec0e43f42d8cc5;hb=7852cb728c839810f4de80b60ba29f29a1fcfa10;hp=b969a19c669f46d53491539f01c082bbe8a7e3ef;hpb=5114cd4c1f8e36f62744a8efa346d619c99bdaf6;p=tpg%2Facess2.git diff --git a/Usermode/Libraries/ld-acess.so_src/elf.c b/Usermode/Libraries/ld-acess.so_src/elf.c index b969a19c..cba670e7 100644 --- a/Usermode/Libraries/ld-acess.so_src/elf.c +++ b/Usermode/Libraries/ld-acess.so_src/elf.c @@ -5,15 +5,20 @@ #include "common.h" #include #include "elf32.h" +#include "elf64.h" -#define DEBUG 0 +#define DEBUG 1 #if DEBUG -# define DEBUGS(v...) SysDebug(v) +# define DEBUGS(v...) SysDebug("ld-acess - " v) #else # define DEBUGS(...) #endif +#if BITS > 32 +# define SUPPORT_ELF64 +#endif + // === 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"}; @@ -21,21 +26,68 @@ static const char *csaR_NAMES[] = {"R_386_NONE", "R_386_32", "R_386_PC32", "R_38 #endif // === PROTOTYPES === -Uint32 ElfHashString(const char *name); +void *ElfRelocate(void *Base, char **envp, const char *Filename); + int ElfGetSymbol(void *Base, const char *Name, void **Ret); +void *Elf32Relocate(void *Base, char **envp, const char *Filename); + int Elf32GetSymbol(void *Base, const char *Name, void **Ret); +#ifdef SUPPORT_ELF64 +void *Elf64Relocate(void *Base, char **envp, const char *Filename); + int Elf64GetSymbol(void *Base, const char *Name, void **Ret); +#endif +Uint32 ElfHashString(const char *name); // === CODE === /** - \fn int ElfRelocate(void *Base, char **envp, char *Filename) - \brief Relocates a loaded ELF Executable -*/ -void *ElfRelocate(void *Base, char **envp, char *Filename) + * \fn int ElfRelocate(void *Base, char **envp, const char *Filename) + * \brief Relocates a loaded ELF Executable + */ +void *ElfRelocate(void *Base, char **envp, const char *Filename) +{ + Elf32_Ehdr *hdr = Base; + + switch(hdr->e_ident[4]) + { + case ELFCLASS32: + return Elf32Relocate(Base, envp, Filename); +#ifdef SUPPORT_ELF64 + case ELFCLASS64: + return Elf64Relocate(Base, envp, Filename); +#endif + default: + SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]); + return NULL; + } +} + +/** + * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret) + */ +int ElfGetSymbol(void *Base, const char *Name, void **ret) +{ + Elf32_Ehdr *hdr = Base; + + switch(hdr->e_ident[4]) + { + case ELFCLASS32: + return Elf32GetSymbol(Base, Name, ret); +#ifdef SUPPORT_ELF64 + case ELFCLASS64: + return Elf64GetSymbol(Base, Name, ret); +#endif + default: + SysDebug("ld-acess - ElfRelocate: Unknown file class %i", hdr->e_ident[4]); + return 0; + } +} + +void *Elf32Relocate(void *Base, char **envp, const char *Filename) { Elf32_Ehdr *hdr = Base; Elf32_Phdr *phtab; int i, j; // Counters char *libPath; - Uint iRealBase = -1; - Uint iBaseDiff; + intptr_t iRealBase = -1; + intptr_t iBaseDiff; int iSegmentCount; int iSymCount; Elf32_Rel *rel = NULL; @@ -48,6 +100,7 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) Elf32_Dyn *dynamicTab = NULL; // Dynamic Table Pointer char *dynstrtab = NULL; // .dynamic String Table Elf32_Sym *dynsymtab; + void (*do_relocate)(uint32_t t_info, uint32_t *ptr, Elf32_Addr addend, int Type, const char *Sym); DEBUGS("ElfRelocate: (Base=0x%x)", Base); @@ -86,7 +139,7 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) // Check if a PT_DYNAMIC segement was found if(!dynamicTab) { SysDebug(" elf_relocate: No PT_DYNAMIC segment in image %p, returning", Base); - return (void *)hdr->entrypoint + iBaseDiff; + return (void *)(intptr_t)(hdr->entrypoint + iBaseDiff); } // Adjust Dynamic Table @@ -103,7 +156,6 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) dynamicTab[j].d_val, dynamicTab[j].d_val + iBaseDiff); if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff; dynsymtab = (void*)(dynamicTab[j].d_val); -// hdr->misc.SymTable = dynamicTab[j].d_val; // Saved in unused bytes of ident break; // --- String Table --- case DT_STRTAB: @@ -115,8 +167,7 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) // --- Hash Table -- case DT_HASH: if(iBaseDiff != 0) dynamicTab[j].d_val += iBaseDiff; - iSymCount = ((Uint*)(dynamicTab[j].d_val))[1]; -// hdr->misc.HashTable = dynamicTab[j].d_val; // Saved in unused bytes of ident + iSymCount = ((Elf32_Word*)(dynamicTab[j].d_val))[1]; break; } } @@ -126,16 +177,6 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) return (void *) hdr->entrypoint + iBaseDiff; } - #if 0 - // Alter Symbols to true base - for(i=0;imachine) + { + case EM_386: + do_relocate = elf_doRelocate_386; + break; + case EM_ARM: + do_relocate = elf_doRelocate_arm; + break; + default: + SysDebug("Elf32Relocate: Unknown machine type %i", hdr->machine); + break; + } // Parse Relocation Entries if(rel && relSz) @@ -252,7 +329,7 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) { //DEBUGS(" Rel %i: 0x%x+0x%x", i, iBaseDiff, rel[i].r_offset); ptr = (void*)(iBaseDiff + rel[i].r_offset); - elf_doRelocate(rel[i].r_info, ptr, *ptr, dynsymtab); + _doRelocate(rel[i].r_info, ptr, *ptr); } } // Parse Relocation Entries @@ -264,7 +341,7 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) for( i = 0; i < j; i++ ) { ptr = (void*)(iBaseDiff + rela[i].r_offset); - elf_doRelocate(rel[i].r_info, ptr, rela[i].r_addend, dynsymtab); + _doRelocate(rel[i].r_info, ptr, rela[i].r_addend); } } @@ -281,7 +358,7 @@ void *ElfRelocate(void *Base, char **envp, char *Filename) for(i=0;ientrypoint + iBaseDiff; } - -/** - * \fn int ElfGetSymbol(Uint Base, const char *name, void **ret) - */ -int ElfGetSymbol(void *Base, const char *Name, void **ret) +int Elf32GetSymbol(void *Base, const char *Name, void **ret) { Elf32_Ehdr *hdr = Base; Elf32_Sym *symtab; @@ -314,40 +387,323 @@ int ElfGetSymbol(void *Base, const char *Name, void **ret) int i; Uint32 *pBuckets; Uint32 *pChains; - Uint iNameHash; + uint32_t iNameHash; + const char *dynstrtab; + uintptr_t iBaseDiff = -1; + Elf32_Phdr *phtab; + Elf32_Dyn *dynTab = NULL; + + // Locate the tables + phtab = (void*)( Base + hdr->phoff ); + for( 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 0; + } + iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff + dynTab = (void*)( (intptr_t)dynTab + iBaseDiff ); + for( 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; // Rebased in Relocate + break; + case DT_STRTAB: + dynstrtab = (void*)(intptr_t) dynTab[i].d_val; + break; + // --- Hash Table -- + case DT_HASH: + pBuckets = (void*)(intptr_t) dynTab[i].d_val; + break; + } + } + + nbuckets = pBuckets[0]; + iSymCount = pBuckets[1]; + pBuckets = &pBuckets[2]; + pChains = &pBuckets[ nbuckets ]; + + // Get hash + iNameHash = ElfHashString(Name); + iNameHash %= nbuckets; + + // Walk Chain + i = pBuckets[ iNameHash ]; + if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) { + *ret = (void*) (intptr_t) symtab[ i ].value + iBaseDiff; + return 1; + } + + while(pChains[i] != STN_UNDEF) + { + i = pChains[i]; + if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) { + *ret = (void*)(intptr_t)symtab[ i ].value + iBaseDiff; + return 1; + } + } + + return 0; +} + +#ifdef SUPPORT_ELF64 +void *Elf64Relocate(void *Base, char **envp, const char *Filename) +{ + int i; + Elf64_Ehdr *hdr = Base; + Elf64_Phdr *phtab; + Elf64_Dyn *dyntab; + Elf64_Addr compiledBase = -1, baseDiff; + Elf64_Sym *symtab = NULL; + char *strtab = NULL; + Elf64_Word *hashtab = NULL; + Elf64_Rel *rel = NULL; + int rel_count = 0; + Elf64_Rela *rela = NULL; + int rela_count = 0; + void *pltrel = NULL; + int plt_size = 0, plt_type = 0; + + DEBUGS("Elf64Relocate: hdr = {"); + DEBUGS("Elf64Relocate: e_ident = '%.16s'", hdr->e_ident); + DEBUGS("Elf64Relocate: e_type = 0x%x", hdr->e_type); + DEBUGS("Elf64Relocate: e_machine = 0x%x", hdr->e_machine); + DEBUGS("Elf64Relocate: e_version = 0x%x", hdr->e_version); + DEBUGS("Elf64Relocate: e_entry = %p", hdr->e_entry); + DEBUGS("Elf64Relocate: e_phoff = 0x%llx", hdr->e_phoff); + DEBUGS("Elf64Relocate: e_shoff = 0x%llx", hdr->e_shoff); + DEBUGS("Elf64Relocate: e_flags = 0x%x", hdr->e_flags); + DEBUGS("Elf64Relocate: e_ehsize = 0x%x", hdr->e_ehsize); + DEBUGS("Elf64Relocate: e_phentsize = 0x%x", hdr->e_phentsize); + DEBUGS("Elf64Relocate: e_phnum = %i", hdr->e_phnum); + + // Scan for the dynamic table (and find the compiled base) + phtab = Base + hdr->e_phoff; + for( i = 0; i < hdr->e_phnum; i ++ ) + { + if(phtab[i].p_type == PT_DYNAMIC) + dyntab = (void *)(intptr_t)phtab[i].p_vaddr; + if(phtab[i].p_type == PT_LOAD && compiledBase > phtab[i].p_vaddr) + compiledBase = phtab[i].p_vaddr; + } + + baseDiff = (Elf64_Addr)Base - compiledBase; + + DEBUGS("baseDiff = %p", baseDiff); + + if(dyntab == NULL) { + SysDebug(" Elf64Relocate: No PT_DYNAMIC segment in image %p, returning", Base); + return (void *)(hdr->e_entry + baseDiff); + } + + dyntab = (void *)((Elf64_Addr)dyntab + baseDiff); + + // Parse the dynamic table (first pass) + // - Search for String, Symbol and Hash tables + for(i = 0; dyntab[i].d_tag != DT_NULL; i ++) + { + switch(dyntab[i].d_tag) + { + case DT_SYMTAB: + dyntab[i].d_un.d_ptr += baseDiff; + symtab = (void *)dyntab[i].d_un.d_ptr; + break; + case DT_STRTAB: + dyntab[i].d_un.d_ptr += baseDiff; + strtab = (void *)dyntab[i].d_un.d_ptr; + break; + case DT_HASH: + dyntab[i].d_un.d_ptr += baseDiff; + hashtab = (void *)dyntab[i].d_un.d_ptr; + break; + } + } + + if( !symtab || !strtab || !hashtab ) { + SysDebug("ld-acess - Elf64Relocate: Missing Symbol, string or hash table"); + return NULL; + } + + // Ready for symbol use + AddLoaded( Filename, Base ); + + // Second pass on dynamic table + for(i = 0; dyntab[i].d_tag != DT_NULL; i ++) + { + DEBUGS("dyntab[%i].d_tag = %i", i, dyntab[i].d_tag); + switch(dyntab[i].d_tag) + { + case DT_SONAME: break; + + case DT_NEEDED: { + char *libPath = strtab + dyntab[i].d_un.d_val; + DEBUGS("Elf64Relocate: libPath = '%s'", libPath); + if(LoadLibrary(libPath, NULL, envp) == 0) { + SysDebug("ld-acess - Elf64Relocate: Unable to load '%s'", libPath); + return NULL; + } + } break; + + // Relocation entries + case DT_REL: + dyntab[i].d_un.d_ptr += baseDiff; + rel = (void *)dyntab[i].d_un.d_ptr; + break; + case DT_RELSZ: + rel_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rel); + break; + case DT_RELENT: + if( dyntab[i].d_un.d_val != sizeof(Elf64_Rel) ) { + SysDebug("ld-acess - Elf64Relocate: DT_RELENT(%i) != sizeof(Elf64_Rel)(%i)", + dyntab[i].d_un.d_val, sizeof(Elf64_Rel)); + return NULL; + } + break; + case DT_RELA: + dyntab[i].d_un.d_ptr += baseDiff; + rela = (void *)dyntab[i].d_un.d_ptr; + break; + case DT_RELASZ: + rela_count = dyntab[i].d_un.d_val / sizeof(Elf64_Rela); + break; + case DT_RELAENT: + if( dyntab[i].d_un.d_val != sizeof(Elf64_Rela) ) { + SysDebug("ld-acess - Elf64Relocate: DT_RELAENT(%i) != sizeof(Elf64_Rela)(%i)", + dyntab[i].d_un.d_val, sizeof(Elf64_Rela)); + return NULL; + } + break; + case DT_JMPREL: + dyntab[i].d_un.d_ptr += baseDiff; + pltrel = (void *)dyntab[i].d_un.d_ptr; + break; + case DT_PLTREL: + plt_type = dyntab[i].d_un.d_val; + break; + case DT_PLTRELSZ: + plt_size = dyntab[i].d_un.d_val; + break; + } + } + + // Relocation function + void _Elf64DoReloc(Elf64_Xword r_info, void *ptr, Elf64_Sxword addend) + { + int sym = ELF64_R_SYM(r_info); + int type = ELF64_R_TYPE(r_info); + const char *symname = strtab + symtab[sym].st_name; + switch( type ) + { + case R_X86_64_NONE: + break; + case R_X86_64_64: + *(uint64_t*)ptr = (uint64_t)GetSymbol(symname) + addend; + break; + case R_X86_64_COPY: + break; + case R_X86_64_GLOB_DAT: + *(uint64_t*)ptr = (uint64_t)GetSymbol(symname); + break; + case R_X86_64_JUMP_SLOT: + *(uint64_t*)ptr = (uint64_t)GetSymbol(symname); + break; + default: + SysDebug("ld-acess - _Elf64DoReloc: Unknown relocation type %i", type); + break; + } + } + + if( rel ) + { + DEBUGS("rel_count = %i", rel_count); + for( i = 0; i < rel_count; i ++ ) + { + uint64_t *ptr = (void *)( rel[i].r_offset + baseDiff ); + _Elf64DoReloc( rel[i].r_info, ptr, *ptr); + } + } + + if( rela ) + { + DEBUGS("rela_count = %i", rela_count); + for( i = 0; i < rela_count; i ++ ) + { + _Elf64DoReloc( rela[i].r_info, (void *)( rela[i].r_offset + baseDiff ), rela[i].r_addend ); + } + } + + if( pltrel && plt_type ) + { + if( plt_type == DT_REL ) { + Elf64_Rel *plt = pltrel; + int count = plt_size / sizeof(Elf64_Rel); + DEBUGS("plt rel count = %i", count); + for( i = 0; i < count; i ++ ) + { + uint64_t *ptr = (void *)( plt[i].r_offset + baseDiff ); + _Elf64DoReloc( plt[i].r_info, ptr, *ptr); + } + } + else { + Elf64_Rela *plt = pltrel; + int count = plt_size / sizeof(Elf64_Rela); + DEBUGS("plt rela count = %i", count); + for( i = 0; i < count; i ++ ) + { + _Elf64DoReloc( plt[i].r_info, (void *)(plt[i].r_offset + baseDiff), plt[i].r_addend); + } + } + } + + DEBUGS("Elf64Relocate: Relocations done, return %p", (void *)(hdr->e_entry + baseDiff)); + return (void *)(hdr->e_entry + baseDiff); +} + +int Elf64GetSymbol(void *Base, const char *Name, void **Ret) +{ + Elf64_Ehdr *hdr = Base; + Elf64_Sym *symtab; + int nbuckets = 0; + int iSymCount = 0; + int i; + Elf64_Word *pBuckets; + Elf64_Word *pChains; + uint32_t iNameHash; const char *dynstrtab; uintptr_t iBaseDiff = -1; - //DEBUGS("ElfGetSymbol: (Base=0x%x, Name='%s')", Base, Name); - #if 0 - pBuckets = (void *) (intptr_t) hdr->misc.HashTable; - symtab = (void *) (intptr_t) hdr->misc.SymTable; - dynstrtab = (void *) (intptr_t) hdr->misc.StrTab; - #else dynstrtab = NULL; pBuckets = NULL; symtab = NULL; - #endif // Catch the current executable if( !pBuckets ) { - Elf32_Phdr *phtab; - Elf32_Dyn *dynTab = NULL; + Elf64_Phdr *phtab; + Elf64_Dyn *dynTab = NULL; int j; // Locate the tables - phtab = (void*)( Base + hdr->phoff ); - for( i = 0; i < hdr->phentcount; i ++ ) + phtab = (void*)( Base + hdr->e_phoff ); + for( i = 0; i < hdr->e_phnum; i ++ ) { - if(phtab[i].Type == PT_LOAD && iBaseDiff > phtab[i].VAddr) - iBaseDiff = phtab[i].VAddr; - if( phtab[i].Type == PT_DYNAMIC ) { - dynTab = (void*)phtab[i].VAddr; + if(phtab[i].p_type == PT_LOAD && iBaseDiff > phtab[i].p_vaddr) + iBaseDiff = phtab[i].p_vaddr; + if( phtab[i].p_type == PT_DYNAMIC ) { + dynTab = (void*)(intptr_t)phtab[i].p_vaddr; } } if( !dynTab ) { - SysDebug("ERROR - Unable to find DYNAMIC segment in %p"); + SysDebug("ERROR - Unable to find DYNAMIC segment in %p", Base); return 0; } iBaseDiff = (intptr_t)Base - iBaseDiff; // Make iBaseDiff actually the diff @@ -359,23 +715,17 @@ int ElfGetSymbol(void *Base, const char *Name, void **ret) { // --- Symbol Table --- case DT_SYMTAB: - symtab = (void*)(intptr_t) dynTab[j].d_val; // Rebased in Relocate + symtab = (void*)(intptr_t) dynTab[j].d_un.d_val; // Rebased in Relocate break; case DT_STRTAB: - dynstrtab = (void*)(intptr_t) dynTab[j].d_val; + dynstrtab = (void*)(intptr_t) dynTab[j].d_un.d_val; break; // --- Hash Table -- case DT_HASH: - pBuckets = (void*)(intptr_t) dynTab[j].d_val; + pBuckets = (void*)(intptr_t) dynTab[j].d_un.d_val; break; } } - - #if 0 - hdr->misc.HashTable = pBucktets; - hdr->misc.SymTable = symtab; - hdr->misc.StrTab = dynstrtab; - #endif } nbuckets = pBuckets[0]; @@ -386,32 +736,29 @@ int ElfGetSymbol(void *Base, const char *Name, void **ret) // Get hash iNameHash = ElfHashString(Name); iNameHash %= nbuckets; - //DEBUGS(" ElfGetSymbol: iNameHash = 0x%x", iNameHash); // Walk Chain i = pBuckets[ iNameHash ]; - //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")", symtab[i].name); - if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].nameOfs, Name) == 0) { - *ret = (void*) (intptr_t) symtab[ i ].value + iBaseDiff; + if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) { + *Ret = (void*) (intptr_t) symtab[i].st_value + iBaseDiff; + DEBUGS("%s = %p", Name, *Ret); return 1; } - //DEBUGS(" ElfGetSymbol: Hash of first = 0x%x", ElfHashString( symtab[i].name ) % nbuckets); while(pChains[i] != STN_UNDEF) { - //DEBUGS(" pChains[%i] = %i", i, pChains[i]); i = pChains[i]; - //DEBUGS(" ElfGetSymbol: strcmp(Name, \"%s\")", symtab[ i ].name); - if(symtab[i].shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[ i ].nameOfs, Name) == 0) { - //DEBUGS("ElfGetSymbol: RETURN 1, '%s' = 0x%x", symtab[ i ].name, symtab[ i ].value); - *ret = (void*)(intptr_t)symtab[ i ].value + iBaseDiff; + if(symtab[i].st_shndx != SHN_UNDEF && strcmp(dynstrtab + symtab[i].st_name, Name) == 0) { + *Ret = (void*)(intptr_t)symtab[i].st_value + iBaseDiff; + DEBUGS("%s = %p", Name, *Ret); return 1; } } - //DEBUGS("ElfGetSymbol: RETURN 0, Symbol '%s' not found", Name); return 0; } +#endif + Uint32 ElfHashString(const char *name) { @@ -426,17 +773,3 @@ Uint32 ElfHashString(const char *name) return h; } -#if 0 -unsigned long elf_hash(const unsigned char *name) -{ - unsigned long h = 0, g; - while (*name) - { - h = (h << 4) + *name++; - if (g = h & 0xf0000000) - h ^= g >> 24; - h &= ~g; - } - return h; -} -#endif