/* * ELF object format helpers * * Copyright (C) 2003-2007 Michael Urman * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND OTHER CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR OTHER CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #ifndef ELF_H_INCLUDED #define ELF_H_INCLUDED typedef struct elf_reloc_entry elf_reloc_entry; typedef struct elf_reloc_head elf_reloc_head; typedef struct elf_secthead elf_secthead; typedef struct elf_strtab_entry elf_strtab_entry; typedef struct elf_strtab_head elf_strtab_head; typedef struct elf_symtab_entry elf_symtab_entry; typedef struct elf_symtab_head elf_symtab_head; typedef struct elf_machine_handler elf_machine_handler; typedef unsigned long elf_address; typedef unsigned long elf_offset; typedef unsigned long elf_size; typedef unsigned long elf_section_info; typedef enum { ET_NONE = 0, ET_REL = 1, /* Relocatable */ ET_EXEC = 2, /* Executable */ ET_DYN = 3, /* Shared object */ ET_CORE = 4, /* Core */ ET_LOOS = 0xfe00, /* Environment specific */ ET_HIOS = 0xfeff, ET_LOPROC = 0xff00, /* Processor specific */ ET_HIPROC = 0xffff } elf_file_type; typedef enum { EM_NONE = 0, EM_M32 = 1, /* AT&T WE 32100 */ EM_SPARC = 2, /* SPARC */ EM_386 = 3, /* Intel 80386 */ EM_68K = 4, /* Motorola 68000 */ EM_88K = 5, /* Motorola 88000 */ EM_860 = 7, /* Intel 80860 */ EM_MIPS = 8, /* MIPS RS3000 */ EM_S370 = 9, /* IBM System/370 */ EM_MIPS_RS4_BE = 10, /* MIPS R4000 Big-Endian (dep)*/ EM_PARISC = 15, /* HPPA */ EM_SPARC32PLUS = 18, /* SPARC v8plus */ EM_PPC = 20, /* PowerPC 32-bit */ EM_PPC64 = 21, /* PowerPC 64-bit */ EM_ARM = 40, /* ARM */ EM_SPARCV9 = 43, /* SPARC v9 64-bit */ EM_IA_64 = 50, /* Intel IA-64 */ EM_X86_64 = 62, /* AMD x86-64 */ EM_ALPHA = 0x9026 /* Alpha (no ABI) */ } elf_machine; typedef enum { ELFMAG0 = 0x7f, ELFMAG1 = 0x45, ELFMAG2 = 0x4c, ELFMAG3 = 0x46 } elf_magic; typedef enum { EV_NONE = 0, /* invalid */ EV_CURRENT = 1 /* current */ } elf_version; typedef enum { EI_MAG0 = 0, /* File id */ EI_MAG1 = 1, EI_MAG2 = 2, EI_MAG3 = 3, EI_CLASS = 4, /* File class */ EI_DATA = 5, /* Data encoding */ EI_VERSION = 6, /* File version */ EI_OSABI = 7, /* OS and ABI */ EI_ABIVERSION = 8, /* version of ABI */ EI_PAD = 9, /* Pad to end; start here */ EI_NIDENT = 16 /* Sizeof e_ident[] */ } elf_identification_index; typedef enum { ELFOSABI_SYSV = 0, /* System V ABI */ ELFOSABI_HPUX = 1, /* HP-UX os */ ELFOSABI_STANDALONE = 255 /* Standalone / embedded app */ } elf_osabi_index; typedef enum { ELFCLASSNONE = 0, /* invalid */ ELFCLASS32 = 1, /* 32-bit */ ELFCLASS64 = 2 /* 64-bit */ } elf_class; typedef enum { ELFDATANONE = 0, ELFDATA2LSB = 1, ELFDATA2MSB = 2 } elf_data_encoding; /* elf section types - index of semantics */ typedef enum { SHT_NULL = 0, /* inactive section - no associated data */ SHT_PROGBITS = 1, /* defined by program for its own meaning */ SHT_SYMTAB = 2, /* symbol table (primarily) for linking */ SHT_STRTAB = 3, /* string table - symbols need names */ SHT_RELA = 4, /* relocation entries w/ explicit addends */ SHT_HASH = 5, /* symbol hash table - for dynamic linking */ SHT_DYNAMIC = 6, /* information for dynamic linking */ SHT_NOTE = 7, /* extra data marking the file somehow */ SHT_NOBITS = 8, /* no stored data, but occupies runtime space */ SHT_REL = 9, /* relocations entries w/o explicit addends */ SHT_SHLIB = 10, /* reserved; unspecified semantics */ SHT_DYNSYM = 11, /* like symtab, but more for dynamic linking */ SHT_LOOS = 0x60000000, /* reserved for environment specific use */ SHT_HIOS = 0x6fffffff, SHT_LOPROC = 0x70000000, /* reserved for processor specific semantics */ SHT_HIPROC = 0x7fffffff/*, SHT_LOUSER = 0x80000000,*/ /* reserved for applications; safe */ /*SHT_HIUSER = 0xffffffff*/ } elf_section_type; /* elf section flags - bitfield of attributes */ typedef enum { SHF_WRITE = 0x1, /* data should be writable at runtime */ SHF_ALLOC = 0x2, /* occupies memory at runtime */ SHF_EXECINSTR = 0x4, /* contains machine instructions */ SHF_MERGE = 0x10, /* data can be merged */ SHF_STRINGS = 0x20, /* contains 0-terminated strings */ SHF_GROUP = 0x200, /* member of a section group */ SHF_TLS = 0x400, /* thread local storage */ SHF_MASKOS = 0x0f000000/*,*//* environment specific use */ /*SHF_MASKPROC = 0xf0000000*/ /* bits reserved for processor specific needs */ } elf_section_flags; /* elf section index - just the special ones */ typedef enum { SHN_UNDEF = 0, /* undefined symbol; requires other global */ SHN_LORESERVE = 0xff00, /* reserved for various semantics */ SHN_LOPROC = 0xff00, /* reserved for processor specific semantics */ SHN_HIPROC = 0xff1f, SHN_LOOS = 0xff20, /* reserved for environment specific use */ SHN_HIOS = 0xff3f, SHN_ABS = 0xfff1, /* associated symbols don't change on reloc */ SHN_COMMON = 0xfff2, /* associated symbols refer to unallocated */ SHN_HIRESERVE = 0xffff } elf_section_index; /* elf symbol binding - index of visibility/behavior */ typedef enum { STB_LOCAL = 0, /* invisible outside defining file */ STB_GLOBAL = 1, /* visible to all combined object files */ STB_WEAK = 2, /* global but lower precedence */ STB_LOOS = 10, /* Environment specific use */ STB_HIOS = 12, STB_LOPROC = 13, /* reserved for processor specific semantics */ STB_HIPROC = 15 } elf_symbol_binding; /* elf symbol type - index of classifications */ typedef enum { STT_NOTYPE = 0, /* type not specified */ STT_OBJECT = 1, /* data object such as a variable, array, etc */ STT_FUNC = 2, /* a function or executable code */ STT_SECTION = 3, /* a section: often for relocation, STB_LOCAL */ STT_FILE = 4, /* often source filename: STB_LOCAL, SHN_ABS */ STT_COMMON = 5, /* Uninitialized common block. */ STT_TLS = 6, /* TLS object. */ STT_NUM = 7, STT_LOOS = 10, /* Environment specific use */ STT_HIOS = 12, STT_LOPROC = 13, /* reserved for processor specific semantics */ STT_HIPROC = 15 } elf_symbol_type; typedef enum { STN_UNDEF = 0 } elf_symbol_index; /* elf symbol visibility - lower two bits of OTHER field */ typedef enum { STV_DEFAULT = 0, /* Default symbol visibility rules */ STV_INTERNAL = 1, /* Processor specific hidden class */ STV_HIDDEN = 2, /* Sym unavailable in other modules */ STV_PROTECTED = 3 /* Not preemptable, not exported */ } elf_symbol_vis; /* internal only object definitions */ #ifdef YASM_OBJFMT_ELF_INTERNAL #define ELF_VISIBILITY_MASK 0x03 #define ELF_ST_VISIBILITY(v) ((v) & ELF_VISIBILITY_MASK) #define ELF32_ST_INFO(bind, type) (((bind) << 4) + ((type) & 0xf)) #define ELF32_R_INFO(s,t) (((s)<<8)+(unsigned char)(t)) #define ELF32_ST_OTHER(vis) ELF_ST_VISIBILITY(vis) #define ELF64_ST_INFO(bind, type) (((bind) << 4) + ((type) & 0xf)) #define ELF64_R_INFO(s,t) (((s)<<32) + ((t) & 0xffffffffL)) #define ELF64_ST_OTHER(vis) ELF_ST_VISIBILITY(vis) #define EHDR32_SIZE 52 #define EHDR64_SIZE 64 #define EHDR_MAXSIZE 64 #define SHDR32_SIZE 40 #define SHDR64_SIZE 64 #define SHDR_MAXSIZE 64 #define SYMTAB32_SIZE 16 #define SYMTAB64_SIZE 24 #define SYMTAB_MAXSIZE 24 #define SYMTAB32_ALIGN 4 #define SYMTAB64_ALIGN 8 #define RELOC32_SIZE 8 #define RELOC32A_SIZE 12 #define RELOC64_SIZE 16 #define RELOC64A_SIZE 24 #define RELOC_MAXSIZE 24 #define RELOC32_ALIGN 4 #define RELOC64_ALIGN 8 /* elf relocation type - index of semantics * * A = Addend (r_addend for RELA, value at location for REL) * B = Base address * G = Offset into global offset table (GOT) * GOT = Address of the global offset table (GOT) * L = Location of procedure linkage table (PLT) * P = Location of location being relocated (r_offset) * S = Value of symbol */ typedef enum { R_386_NONE = 0, /* none */ R_386_32 = 1, /* word32, S + A */ R_386_PC32 = 2, /* word32, S + A - P */ R_386_GOT32 = 3, /* word32, G + A - P */ R_386_PLT32 = 4, /* word32, L + A - P */ R_386_COPY = 5, /* none */ R_386_GLOB_DAT = 6, /* word32, S */ R_386_JMP_SLOT = 7, /* word32, S */ R_386_RELATIVE = 8, /* word32, B + A */ R_386_GOTOFF = 9, /* word32, S + A - GOT */ R_386_GOTPC = 10, /* word32, GOT + A - P */ R_386_TLS_TPOFF = 14, /* Negative offset in static TLS block (GNU version) */ R_386_TLS_IE = 15, /* Absolute address of GOT entry for negative static TLS block offset */ R_386_TLS_GOTIE = 16, /* GOT entry for negative static TLS block offset */ R_386_TLS_LE = 17, /* Negative offset relative to static TLS (GNU version) */ R_386_TLS_GD = 18, /* Direct 32 bit for GNU version of GD TLS */ R_386_TLS_LDM = 19, /* Direct 32 bit for GNU version of LD TLS in LE code */ R_386_16 = 20, /* word16, S + A (GNU extension) */ R_386_PC16 = 21, /* word16, S + A - P (GNU extension) */ R_386_8 = 22, /* word8, S + A (GNU extension) */ R_386_PC8 = 23, /* word8, S + A - P (GNU extension) */ R_386_TLS_GD_32 = 24, /* Direct 32 bit for GD TLS */ R_386_TLS_GD_PUSH = 25, /* Tag for pushl in GD TLS code */ R_386_TLS_GD_CALL = 26, /* Relocation for call to */ R_386_TLS_GD_POP = 27, /* Tag for popl in GD TLS code */ R_386_TLS_LDM_32 = 28, /* Direct 32 bit for local dynamic code */ R_386_TLS_LDM_PUSH = 29, /* Tag for pushl in LDM TLS code */ R_386_TLS_LDM_CALL = 30, /* Relocation for call to */ R_386_TLS_LDM_POP = 31, /* Tag for popl in LDM TLS code */ R_386_TLS_LDO_32 = 32, /* Offset relative to TLS block */ R_386_TLS_IE_32 = 33, /* GOT entry for static TLS block */ R_386_TLS_LE_32 = 34, /* Offset relative to static TLS block */ R_386_TLS_DTPMOD32 = 35, /* ID of module containing symbol */ R_386_TLS_DTPOFF32 = 36, /* Offset in TLS block */ R_386_TLS_TPOFF32 = 37, /* Offset in static TLS block */ R_386_TLS_GOTDESC = 39, R_386_TLS_DESC_CALL = 40, R_386_TLS_DESC = 41 } elf_386_relocation_type; typedef enum { R_X86_64_NONE = 0, /* none */ R_X86_64_64 = 1, /* word64, S + A */ R_X86_64_PC32 = 2, /* word32, S + A - P */ R_X86_64_GOT32 = 3, /* word32, G + A */ R_X86_64_PLT32 = 4, /* word32, L + A - P */ R_X86_64_COPY = 5, /* none */ R_X86_64_GLOB_DAT = 6, /* word64, S, set GOT entry to data address */ R_X86_64_JMP_SLOT = 7, /* word64, S, set GOT entry to code address */ R_X86_64_RELATIVE = 8, /* word64, B + A */ R_X86_64_GOTPCREL = 9, /* word32, G + GOT + A - P */ R_X86_64_32 = 10, /* word32 (zero extend), S + A */ R_X86_64_32S = 11, /* word32 (sign extend), S + A */ R_X86_64_16 = 12, /* word16, S + A */ R_X86_64_PC16 = 13, /* word16, S + A - P */ R_X86_64_8 = 14, /* word8, S + A */ R_X86_64_PC8 = 15, /* word8, S + A - P */ R_X86_64_DPTMOD64 = 16, /* word64, ID of module containing symbol */ R_X86_64_DTPOFF64 = 17, /* word64, offset in TLS block */ R_X86_64_TPOFF64 = 18, /* word64, offset in initial TLS block */ R_X86_64_TLSGD = 19, /* word32, PC-rel offset to GD GOT block */ R_X86_64_TLSLD = 20, /* word32, PC-rel offset to LD GOT block */ R_X86_64_DTPOFF32 = 21, /* word32, offset to TLS block */ R_X86_64_GOTTPOFF = 22, /* word32, PC-rel offset to IE GOT entry */ R_X86_64_TPOFF32 = 23, /* word32, offset in initial TLS block */ R_X86_64_PC64 = 24, /* word64, PC relative */ R_X86_64_GOTOFF64 = 25, /* word64, offset to GOT */ R_X86_64_GOTPC32 = 26, /* word32, signed pc relative to GOT */ R_X86_64_GOT64 = 27, /* word64, GOT entry offset */ R_X86_64_GOTPCREL64 = 28, /* word64, signed pc relative to GOT entry */ R_X86_64_GOTPC64 = 29, /* word64, signed pc relative to GOT */ R_X86_64_GOTPLT64 = 30, /* like GOT64, but indicates PLT entry needed */ R_X86_64_PLTOFF64 = 31, /* word64, GOT relative offset to PLT entry */ R_X86_64_GOTPC32_TLSDESC = 34, /* GOT offset for TLS descriptor */ R_X86_64_TLSDESC_CALL = 35, /* Marker for call through TLS descriptor */ R_X86_64_TLSDESC = 36 /* TLS descriptor */ } elf_x86_64_relocation_type; struct elf_secthead { elf_section_type type; elf_section_flags flags; elf_address offset; yasm_intnum *size; elf_section_index link; elf_section_info info; /* see note ESD1 */ unsigned long align; elf_size entsize; yasm_symrec *sym; elf_strtab_entry *name; elf_section_index index; elf_strtab_entry *rel_name; elf_section_index rel_index; elf_address rel_offset; unsigned long nreloc; }; /* Note ESD1: * for section types SHT_REL, SHT_RELA: * link -> index of associated symbol table * info -> index of relocated section * for section types SHT_SYMTAB, SHT_DYNSYM: * link -> index of associated string table * info -> 1+index of last "local symbol" (bind == STB_LOCAL) * (for section type SHT_DNAMIC: * link -> index of string table * info -> 0 ) * (for section type SHT_HASH: * link -> index of symbol table to which hash applies * info -> 0 ) * for all others: * link -> SHN_UNDEF * info -> 0 */ struct elf_reloc_entry { yasm_reloc reloc; int rtype_rel; size_t valsize; yasm_intnum *addend; /*@null@*/ yasm_symrec *wrt; int is_GOT_sym; }; STAILQ_HEAD(elf_strtab_head, elf_strtab_entry); struct elf_strtab_entry { STAILQ_ENTRY(elf_strtab_entry) qlink; unsigned long index; char *str; }; STAILQ_HEAD(elf_symtab_head, elf_symtab_entry); struct elf_symtab_entry { STAILQ_ENTRY(elf_symtab_entry) qlink; int in_table; yasm_symrec *sym; yasm_section *sect; elf_strtab_entry *name; elf_address value; /*@dependent@*/ yasm_expr *xsize; elf_size size; elf_section_index index; elf_symbol_binding bind; elf_symbol_type type; elf_symbol_vis vis; elf_symbol_index symindex; }; #endif /* defined(YASM_OBJFMT_ELF_INTERNAL) */ extern const yasm_assoc_data_callback elf_section_data; extern const yasm_assoc_data_callback elf_symrec_data; extern const yasm_assoc_data_callback elf_ssym_symrec_data; const elf_machine_handler *elf_set_arch(struct yasm_arch *arch, yasm_symtab *symtab, int bits_pref); yasm_symrec *elf_get_special_sym(const char *name, const char *parser); /* reloc functions */ int elf_is_wrt_sym_relative(yasm_symrec *wrt); int elf_is_wrt_pos_adjusted(yasm_symrec *wrt); elf_reloc_entry *elf_reloc_entry_create(yasm_symrec *sym, /*@null@*/ yasm_symrec *wrt, yasm_intnum *addr, int rel, size_t valsize, int is_GOT_sym); void elf_reloc_entry_destroy(void *entry); /* strtab functions */ elf_strtab_entry *elf_strtab_entry_create(const char *str); void elf_strtab_entry_set_str(elf_strtab_entry *entry, const char *str); elf_strtab_head *elf_strtab_create(void); elf_strtab_entry *elf_strtab_append_str(elf_strtab_head *head, const char *str); void elf_strtab_destroy(elf_strtab_head *head); unsigned long elf_strtab_output_to_file(FILE *f, elf_strtab_head *head); /* symtab functions */ elf_symtab_entry *elf_symtab_entry_create(elf_strtab_entry *name, struct yasm_symrec *sym); elf_symtab_head *elf_symtab_create(void); void elf_symtab_append_entry(elf_symtab_head *symtab, elf_symtab_entry *entry); void elf_symtab_insert_local_sym(elf_symtab_head *symtab, elf_symtab_entry *entry); void elf_symtab_destroy(elf_symtab_head *head); unsigned long elf_symtab_assign_indices(elf_symtab_head *symtab); unsigned long elf_symtab_write_to_file(FILE *f, elf_symtab_head *symtab, yasm_errwarns *errwarns); void elf_symtab_set_nonzero(elf_symtab_entry *entry, struct yasm_section *sect, elf_section_index sectidx, elf_symbol_binding bind, elf_symbol_type type, struct yasm_expr *size, elf_address *value); void elf_sym_set_visibility(elf_symtab_entry *entry, elf_symbol_vis vis); void elf_sym_set_type(elf_symtab_entry *entry, elf_symbol_type type); void elf_sym_set_size(elf_symtab_entry *entry, struct yasm_expr *size); int elf_sym_in_table(elf_symtab_entry *entry); /* section header functions */ elf_secthead *elf_secthead_create(elf_strtab_entry *name, elf_section_type type, elf_section_flags flags, elf_address offset, elf_size size); void elf_secthead_destroy(elf_secthead *esd); unsigned long elf_secthead_write_to_file(FILE *f, elf_secthead *esd, elf_section_index sindex); void elf_secthead_append_reloc(yasm_section *sect, elf_secthead *shead, elf_reloc_entry *reloc); elf_section_type elf_secthead_get_type(elf_secthead *shead); void elf_secthead_set_typeflags(elf_secthead *shead, elf_section_type type, elf_section_flags flags); int elf_secthead_is_empty(elf_secthead *shead); struct yasm_symrec *elf_secthead_get_sym(elf_secthead *shead); unsigned long elf_secthead_get_align(const elf_secthead *shead); unsigned long elf_secthead_set_align(elf_secthead *shead, unsigned long align); elf_section_index elf_secthead_get_index(elf_secthead *shead); elf_section_info elf_secthead_set_info(elf_secthead *shead, elf_section_info info); elf_section_index elf_secthead_set_index(elf_secthead *shead, elf_section_index sectidx); elf_section_index elf_secthead_set_link(elf_secthead *shead, elf_section_index link); elf_section_index elf_secthead_set_rel_index(elf_secthead *shead, elf_section_index sectidx); elf_strtab_entry *elf_secthead_set_rel_name(elf_secthead *shead, elf_strtab_entry *entry); elf_size elf_secthead_set_entsize(elf_secthead *shead, elf_size size); struct yasm_symrec *elf_secthead_set_sym(elf_secthead *shead, struct yasm_symrec *sym); void elf_secthead_add_size(elf_secthead *shead, yasm_intnum *size); char *elf_secthead_name_reloc_section(const char *basesect); void elf_handle_reloc_addend(yasm_intnum *intn, elf_reloc_entry *reloc, unsigned long offset); unsigned long elf_secthead_write_rel_to_file(FILE *f, elf_section_index symtab, yasm_section *sect, elf_secthead *esd, elf_section_index sindex); unsigned long elf_secthead_write_relocs_to_file(FILE *f, yasm_section *sect, elf_secthead *shead, yasm_errwarns *errwarns); long elf_secthead_set_file_offset(elf_secthead *shead, long pos); /* program header function */ unsigned long elf_proghead_get_size(void); unsigned long elf_proghead_write_to_file(FILE *f, elf_offset secthead_addr, unsigned long secthead_count, elf_section_index shstrtab_index); #endif /* ELF_H_INCLUDED */