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Diffstat (limited to 'checklink/ELF_parsers.ml')
| -rw-r--r-- | checklink/ELF_parsers.ml | 362 |
1 files changed, 0 insertions, 362 deletions
diff --git a/checklink/ELF_parsers.ml b/checklink/ELF_parsers.ml deleted file mode 100644 index 8c2d486c..00000000 --- a/checklink/ELF_parsers.ml +++ /dev/null @@ -1,362 +0,0 @@ -open Bitstring_utils -open ELF_types -open ELF_printers -open ELF_utils -open Library -open PPC_parsers - -(** Allows relaxations of the parser: - - 1. Any segment that has the same p_offset and p_memsz as another segment, - and a null p_filesz, will be considered as having a p_filesz equal to the - other segment. This allow symbol's contents resolution to succeed even in - the presence of a bootstrapping copy mechanism from one segment to the - other. -*) -let relaxed = ref false - -exception Unknown_endianness - -(** Converts an elf endian into a bitstring endian *) -let elfdata_to_endian (e: elfdata): Bitstring.endian = - match e with - | ELFDATA2LSB -> Bitstring.LittleEndian - | ELFDATA2MSB -> Bitstring.BigEndian - | _ -> raise Unknown_endianness - -(** Parses an elf32 header *) -let read_elf32_ehdr (bs: bitstring): elf32_ehdr = - bitmatch bs with - | { e_ident : 16*8 : bitstring ; - rest : -1 : bitstring } -> - ( - bitmatch e_ident with - | { 0x7F : 8 ; - "ELF" : 24 : string ; - ei_class : 8 : int ; - ei_data : 8 : int ; - ei_version : 8 : int ; - padding : 72 : bitstring } -> - assert (is_zeros padding 72); - let ei_data = - begin match ei_data with - | 0 -> ELFDATANONE - | 1 -> ELFDATA2LSB - | 2 -> ELFDATA2MSB - | _ -> ELFDATAUNKNOWN - end - in - let e = elfdata_to_endian ei_data in - ( - bitmatch rest with - | { e_type : 16 : int, endian(e) ; - e_machine : 16 : int, endian(e) ; - e_version : 32 : int, endian(e) ; - e_entry : 32 : int, endian(e) ; - e_phoff : 32 : int, endian(e) ; - e_shoff : 32 : int, endian(e) ; - e_flags : 32 : bitstring ; - e_ehsize : 16 : int, endian(e) ; - e_phentsize : 16 : int, endian(e) ; - e_phnum : 16 : int, endian(e) ; - e_shentsize : 16 : int, endian(e) ; - e_shnum : 16 : int, endian(e) ; - e_shstrndx : 16 : int, endian(e) } -> - (* These shouldn't be different than this... *) - assert (e_ehsize = 52); - assert (e_phentsize = 32); - assert (e_shentsize = 40); - { - e_ident = - { - ei_class = - begin match ei_class with - | 0 -> ELFCLASSNONE - | 1 -> ELFCLASS32 - | 2 -> ELFCLASS64 - | _ -> ELFCLASSUNKNOWN - end; - ei_data = ei_data; - ei_version = - begin match ei_version with - | 0 -> EV_NONE - | 1 -> EV_CURRENT - | _ -> EV_UNKNOWN - end; - }; - e_type = - begin match e_type with - | 0 -> ET_NONE - | 1 -> ET_REL - | 2 -> ET_EXEC - | 3 -> ET_DYN - | 4 -> ET_CORE - | _ -> ET_UNKNOWN - end; - e_machine = - begin match e_machine with - | 0 -> EM_NONE - | 1 -> EM_M32 - | 2 -> EM_SPARC - | 3 -> EM_386 - | 4 -> EM_68K - | 5 -> EM_88K - | 7 -> EM_860 - | 8 -> EM_MIPS - | 10 -> EM_MIPS_RS4_BE - | 20 -> EM_PPC - | _ -> EM_UNKNOWN - end; - e_version = - begin match e_version with - | 0l -> EV_NONE - | 1l -> EV_CURRENT - | _ -> EV_UNKNOWN - end; - e_entry = e_entry; - e_phoff = e_phoff; - e_shoff = e_shoff; - e_flags = e_flags; - e_ehsize = e_ehsize; - e_phentsize = e_phentsize; - e_phnum = e_phnum; - e_shentsize = e_shentsize; - e_shnum = e_shnum; - e_shstrndx = e_shstrndx; - } - ) - ) - -(** Returns the file offset of the section header indexed *) -let section_header_offset (e_hdr: elf32_ehdr) (sndx: int): int = - Safe.(of_int32 e_hdr.e_shoff + (sndx * e_hdr.e_shentsize)) - -(** Returns the ndx-th string in the provided bitstring, according to null - characters *) -let strtab_string (bs: bitstring) (ndx: int): string = - let (str, ofs, _) = bs in - let start = (ofs / 8 + ndx) in - String.sub str start (String.index_from str start '\000' - start) - -(** Reads an ELF section header *) -let read_elf32_shdr (e_hdr: elf32_ehdr) (bs: bitstring) (strtab: bitstring) - (num: int): elf32_shdr = - let e = elfdata_to_endian e_hdr.e_ident.ei_data in - let bit_ofs = Safe.( - (section_header_offset e_hdr num) * 8 - ) in - bitmatch bs with - | { sh_name : 32 : endian(e), offset(bit_ofs) ; - sh_type : 32 : endian(e) ; - sh_flags : 32 : endian(e) ; - sh_addr : 32 : endian(e) ; - sh_offset : 32 : endian(e) ; - sh_size : 32 : endian(e) ; - sh_link : 32 : endian(e) ; - sh_info : 32 : endian(e) ; - sh_addralign : 32 : endian(e) ; - sh_entsize : 32 : endian(e) } -> - { - sh_name = strtab_string strtab (Safe32.to_int sh_name); - sh_type = - begin match sh_type with - | 0l -> SHT_NULL - | 1l -> SHT_PROGBITS - | 2l -> SHT_SYMTAB - | 3l -> SHT_STRTAB - | 4l -> SHT_RELA - | 5l -> SHT_HASH - | 6l -> SHT_DYNAMIC - | 7l -> SHT_NOTE - | 8l -> SHT_NOBITS - | 9l -> SHT_REL - | 10l -> SHT_SHLIB - | 11l -> SHT_DYNSYM - | _ -> SHT_UNKNOWN - end; - sh_flags = sh_flags ; - sh_addr = sh_addr ; - sh_offset = sh_offset ; - sh_size = sh_size ; - sh_link = sh_link ; - sh_info = sh_info ; - sh_addralign = sh_addralign ; - sh_entsize = sh_entsize ; - } - -(** Reads an elf program header *) -let read_elf32_phdr (e_hdr: elf32_ehdr) (bs: bitstring) (ndx: int): elf32_phdr = - let e = elfdata_to_endian e_hdr.e_ident.ei_data in - let bit_ofs = Safe.( - ((of_int32 e_hdr.e_phoff) + (ndx * e_hdr.e_phentsize)) * 8 - ) in - bitmatch bs with - | { p_type : 32 : endian(e), offset(bit_ofs) ; - p_offset : 32 : endian(e) ; - p_vaddr : 32 : endian(e) ; - p_paddr : 32 : endian(e) ; - p_filesz : 32 : endian(e) ; - p_memsz : 32 : endian(e) ; - p_flags : 32 : bitstring ; - p_align : 32 : endian(e) } -> - { - p_type = - begin match p_type with - | 0l -> PT_NULL - | 1l -> PT_LOAD - | 2l -> PT_DYNAMIC - | 3l -> PT_INTERP - | 4l -> PT_NOTE - | 5l -> PT_SHLIB - | 6l -> PT_PHDR - | _ -> PT_UNKNOWN - end; - p_offset = p_offset ; - p_vaddr = p_vaddr ; - p_paddr = p_paddr ; - p_filesz = p_filesz ; - p_memsz = p_memsz ; - p_flags = p_flags ; - p_align = p_align ; - } - -(** Reads an ELF symbol *) -let read_elf32_sym (e_hdr: elf32_ehdr) (symtab: bitstring) (strtab: bitstring) - (num: int): elf32_sym = - let e = elfdata_to_endian e_hdr.e_ident.ei_data in - let bit_ofs = Safe.(num * 128) in (* each symbol takes 16 bytes = 128 bits *) - bitmatch symtab with - | { st_name : 32 : endian(e), offset(bit_ofs) ; - st_value : 32 : endian(e) ; - st_size : 32 : endian(e) ; - st_bind : 4 ; - st_type : 4 ; - st_other : 8 ; - st_shndx : 16 : endian(e) } -> - { - st_name = strtab_string strtab (Safe32.to_int st_name) ; - st_value = st_value ; - st_size = st_size ; - st_bind = - begin match st_bind with - | 0 -> STB_LOCAL - | 1 -> STB_GLOBAL - | 2 -> STB_WEAK - | _ -> STB_UNKNOWN - end; - st_type = - begin match st_type with - | 0 -> STT_NOTYPE - | 1 -> STT_OBJECT - | 2 -> STT_FUNC - | 3 -> STT_SECTION - | 4 -> STT_FILE - | _ -> STT_UNKNOWN - end; - st_other = st_other ; - st_shndx = st_shndx ; - } - -(** Reads a whole ELF file from a bitstring *) -let read_elf_bs (bs: bitstring): elf = - let e_hdr = read_elf32_ehdr bs in - (* To initialize section names we need the string table *) - let strtab = ( - let e = elfdata_to_endian e_hdr.e_ident.ei_data in - let strtab_sndx = e_hdr.e_shstrndx in - let strtab_shofs = section_header_offset e_hdr strtab_sndx in - let skipped_bits = Safe.(strtab_shofs * 8 + 128) in - bitmatch bs with - | { ofs : 32 : endian(e), offset(skipped_bits) ; - size : 32 : endian(e) } -> - Bitstring.subbitstring bs Safe.(of_int32 ofs * 8) Safe.(of_int32 size * 8) - ) - in - let e_shdra = - Array.init e_hdr.e_shnum (read_elf32_shdr e_hdr bs strtab) - in - let symtab_sndx = section_ndx_by_name_noelf e_shdra ".symtab" in - let e_symtab = ( - let symtab_shdr = e_shdra.(symtab_sndx) in - let symtab_strtab_sndx = symtab_shdr.sh_link in - let symtab_nb_ent = (Safe32.to_int symtab_shdr.sh_size / 16) in - Array.init symtab_nb_ent - (read_elf32_sym e_hdr - (section_bitstring_noelf bs e_shdra symtab_sndx) - (section_bitstring_noelf bs e_shdra (Safe32.to_int symtab_strtab_sndx))) - ) in - let e_phdra = - let untweaked = Array.init e_hdr.e_phnum (read_elf32_phdr e_hdr bs) in - if !relaxed - then - Array.mapi - (fun ndx curr -> - if ndx < 1 - then curr - else - let prev = untweaked.(ndx - 1) in - if (curr.p_offset = prev.p_offset) - && (curr.p_memsz = prev.p_memsz) - then { curr with p_filesz = prev.p_filesz } - else curr - ) - untweaked - else untweaked - in - let e_sym_phdr = - let intervals = - Array.mapi - (fun ndx phdr -> (* (ndx, (start, stop), type) *) - (ndx, - (phdr.p_vaddr, Safe32.(phdr.p_vaddr + phdr.p_memsz - 1l)), - phdr.p_type - ) - ) - e_phdra - in - let intervals = Array.of_list ( - List.filter - (function (_, _, PT_LOAD) -> true | _ -> false) - (Array.to_list intervals) - ) in - Array.fast_sort (fun (_, (x, _), _) (_, (y, _), _) -> compare x y) intervals; - let lookup = - sorted_lookup - ( - fun (_, (a, b), _) v -> - if a <= v && v <= b - then 0 - else compare a v - ) - intervals - in - fun vaddr -> - begin match lookup vaddr with - | None -> None - | Some(ndx, (_, _), _) -> Some(ndx) - end - in - let e_syms_by_name = - let m = ref StringMap.empty in - for i = 0 to Array.length e_symtab - 1 do - let name = strip_versioning e_symtab.(i).st_name in - let list = try StringMap.find name !m with Not_found -> [] in - m := StringMap.add name (i :: list) !m - done; - !m - in - { - e_bitstring = bs; - e_hdr = e_hdr; - e_shdra = e_shdra; - e_phdra = e_phdra; - e_symtab = e_symtab; - e_symtab_sndx = symtab_sndx; - e_sym_phdr = e_sym_phdr; - e_syms_by_name = e_syms_by_name; - } - -(** Reads a whole ELF file from a file name *) -let read_elf (elffilename: string): elf = - let bs = Bitstring.bitstring_of_file elffilename in - read_elf_bs bs |