Source file elf_file.ml
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(** Module [elf_file] packages all components of an ELF file up into a single
* record, provides I/O routines for this record, as well as other utility
* functions that operate on an entire ELF file.
*)
open Lem_basic_classes
open Lem_bool
open Lem_list
open Lem_num
open Lem_maybe
open Lem_string
open Elf_header
open Elf_interpreted_section
open Elf_interpreted_segment
open Elf_types_native_uint
open Elf_section_header_table
open Elf_symbol_table
open Elf_program_header_table
open String_table
open Byte_sequence
open Error
open Missing_pervasives
open Show
(** [elf32_file] record captures the internal structure of an ELF32 file.
* Invariant: length of the program header and section header tables should match
* the length of their interpreted counterparts, and the nth element of the
* (program/section) header table must correspond to the nth element of the
* interpreted (segments/sections), respectively.
*)
type elf32_file =
{ elf32_file_header : elf32_header (** The file header. *)
; elf32_file_program_header_table : elf32_program_header_table (** The program header table. *)
; elf32_file_section_header_table : elf32_section_header_table (** The section header table. *)
; elf32_file_interpreted_segments : elf32_interpreted_segments (** A more usable interpretation of the file's segments. *)
; elf32_file_interpreted_sections : elf32_interpreted_sections (** A more usable interpretation of the file's sections. *)
; elf32_file_bits_and_bobs : (Nat_big_num.num * byte_sequence0) list (** The uninterpreted "rubbish" that may appear in gaps in the binary file. *)
}
(** [bytes_of_elf32_file f1] blits ELF file [f1] to a byte sequence, ready for
* writing to a binary file. Fails if the invariant on [elf32_file] mentioned
* above is not respected.
*)
let bytes_of_elf32_file ef:(Byte_sequence_wrapper.byte_sequence)error=
(let endian = (get_elf32_header_endianness ef.elf32_file_header) in
let hdr_bytes = (bytes_of_elf32_header ef.elf32_file_header) in
let hdr_layout = ( (Nat_big_num.of_int 0), hdr_bytes) in
let pht_bytes = (bytes_of_elf32_program_header_table endian ef.elf32_file_program_header_table) in
let sht_bytes = (bytes_of_elf32_section_header_table endian ef.elf32_file_section_header_table) in
let pht_off = (Uint32_wrapper.to_bigint ef.elf32_file_header.elf32_phoff) in
let sht_off = (Uint32_wrapper.to_bigint ef.elf32_file_header.elf32_shoff) in
let pht_layout = (pht_off, pht_bytes) in
let sht_layout = (sht_off, sht_bytes) in
let bab_layout = (ef.elf32_file_bits_and_bobs) in
if List.length ef.elf32_file_program_header_table =
List.length ef.elf32_file_interpreted_segments then
if List.length ef.elf32_file_section_header_table =
List.length ef.elf32_file_interpreted_sections then
let segs_zip = (Lem_list.list_combine ef.elf32_file_program_header_table ef.elf32_file_interpreted_segments) in
let sects_zip = (Lem_list.list_combine ef.elf32_file_section_header_table ef.elf32_file_interpreted_sections) in
let segs_layout =
(Lem_list.map (fun (seg, interp_seg) ->
(Uint32_wrapper.to_bigint seg.elf32_p_offset, interp_seg.elf32_segment_body)
) (List.filter (fun (x, _) -> not (x.elf32_p_filesz = (Uint32_wrapper.of_bigint( (Nat_big_num.of_int 0))))) segs_zip))
in
let sects_layout =
(Lem_list.map (fun (sect, interp_sect) ->
(Uint32_wrapper.to_bigint sect.elf32_sh_offset, interp_sect.elf32_section_body)
) (List.filter (fun (x, _) -> not (x.elf32_sh_type = (Uint32_wrapper.of_bigint sht_nobits))) sects_zip))
in
let pre_layout = (List.rev_append (List.rev (List.rev_append (List.rev (List.rev_append (List.rev [hdr_layout; pht_layout; sht_layout]) sects_layout)) segs_layout)) bab_layout) in
let final_layout =
(List.sort (fun (off_x, _) (off_y, _) -> Nat_big_num.compare off_x off_y)
pre_layout)
in
let concats =
(foldM (fun x y ->
let (current_offset, so_far) = x in
let (point_to_add, body) = y in
if Nat_big_num.less point_to_add current_offset then
let diff = (Nat_big_num.sub_nat current_offset point_to_add) in
if Nat_big_num.less (Byte_sequence.length0 body) diff then
return (current_offset, so_far)
else bind (Byte_sequence.partition0 diff body) (fun (_, cut) ->
let concat2 = (Byte_sequence.concat [so_far; cut]) in
let delta = (Nat_big_num.add current_offset (Byte_sequence.length0 cut)) in
return (delta, concat2))
else
let diff = (Nat_big_num.sub_nat point_to_add current_offset) in
let reps = (Byte_sequence.create diff '\000') in
let concat2 = (Byte_sequence.concat [so_far; reps; body]) in
let delta = (Nat_big_num.add point_to_add (Byte_sequence.length0 body)) in
return (delta, concat2)
) ( (Nat_big_num.of_int 0), Byte_sequence.empty) final_layout)
in bind concats (fun (offset, body) ->
return body)
else
fail "bytes_of_elf32_file: interpreted sections and section header table must have same length"
else
fail "bytes_of_elf32_file: interpreted segments and program header table must have same length")
(** [elf64_file] record captures the internal structure of an ELF32 file.
* Invariant: length of the program header and section header tables should match
* the length of their interpreted counterparts, and the nth element of the
* (program/section) header table must correspond to the nth element of the
* interpreted (segments/sections), respectively.
*)
type elf64_file =
{ elf64_file_header : elf64_header (** The file header. *)
; elf64_file_program_header_table : elf64_program_header_table (** The program header table. *)
; elf64_file_section_header_table : elf64_section_header_table (** The section header table. *)
; elf64_file_interpreted_segments : elf64_interpreted_segments (** A more usable interpretation of the file's segments. *)
; elf64_file_interpreted_sections : elf64_interpreted_sections (** A more usable interpretation of the file's sections. *)
; elf64_file_bits_and_bobs : (Nat_big_num.num * byte_sequence0) list (** The uninterpreted "rubbish" that may appear in gaps in the binary file. *)
}
type elf_file =
| ELF_File_32 of elf32_file
| ELF_File_64 of elf64_file
(** [bytes_of_elf64_file f1] blits ELF file [f1] to a byte sequence, ready for
* writing to a binary file. Fails if the invariant on [elf64_file] mentioned
* above is not respected.
*)
let bytes_of_elf64_file ef:(Byte_sequence_wrapper.byte_sequence)error=
(let endian = (get_elf64_header_endianness ef.elf64_file_header) in
let hdr_bytes = (bytes_of_elf64_header ef.elf64_file_header) in
let hdr_layout = ( (Nat_big_num.of_int 0), hdr_bytes) in
let pht_bytes = (bytes_of_elf64_program_header_table endian ef.elf64_file_program_header_table) in
let sht_bytes = (bytes_of_elf64_section_header_table endian ef.elf64_file_section_header_table) in
let pht_off = (Uint64_wrapper.to_bigint ef.elf64_file_header.elf64_phoff) in
let sht_off = (Uint64_wrapper.to_bigint ef.elf64_file_header.elf64_shoff) in
let pht_layout = (pht_off, pht_bytes) in
let sht_layout = (sht_off, sht_bytes) in
let bab_layout = (ef.elf64_file_bits_and_bobs) in
if true then
if List.length ef.elf64_file_section_header_table =
List.length ef.elf64_file_interpreted_sections then
let segs_zip = (Lem_list.list_combine ef.elf64_file_program_header_table ef.elf64_file_interpreted_segments) in
let sects_zip = (Lem_list.list_combine ef.elf64_file_section_header_table ef.elf64_file_interpreted_sections) in
let segs_layout = ([])
in
let sects_layout =
(Lem_list.map (fun (sect, interp_sect) ->
(Uint64_wrapper.to_bigint sect.elf64_sh_offset, interp_sect.elf64_section_body)
) (List.filter (fun (x, _) -> not (x.elf64_sh_type = (Uint32_wrapper.of_bigint sht_nobits))) sects_zip))
in
let pre_layout = (List.rev_append (List.rev (List.rev_append (List.rev (List.rev_append (List.rev [hdr_layout; pht_layout; sht_layout]) sects_layout)) segs_layout)) bab_layout) in
let final_layout =
(List.sort (fun (off_x, _) (off_y, _) -> Nat_big_num.compare off_x off_y)
pre_layout)
in
let concats =
(foldM (fun x y ->
let (current_offset, so_far) = x in
let (point_to_add, body) = y in
if Nat_big_num.less point_to_add current_offset then
let diff = (Nat_big_num.sub_nat current_offset point_to_add) in
if Nat_big_num.less (Byte_sequence.length0 body) diff then
return (current_offset, so_far)
else bind (Byte_sequence.partition0 diff body) (fun (_, cut) ->
let concat2 = (Byte_sequence.concat [so_far; cut]) in
let delta = (Nat_big_num.add current_offset (Byte_sequence.length0 cut)) in
return (delta, concat2))
else
let diff = (Nat_big_num.sub_nat point_to_add current_offset) in
let reps = (Byte_sequence.create diff '\000') in
let concat2 = (Byte_sequence.concat [so_far; reps; body]) in
let delta = (Nat_big_num.add point_to_add (Byte_sequence.length0 body)) in
return (delta, concat2)
) ( (Nat_big_num.of_int 0), Byte_sequence.empty) final_layout)
in bind concats (fun (offset, body) ->
return body)
else
fail "bytes_of_elf64_file: interpreted sections and section header table must have same length"
else
fail "bytes_of_elf64_file: interpreted segments and program header table must have same length")
(** [obtain_elf32_program_header_table hdr bs0] reads a file's program header table
* from byte sequence [bs0] using information gleaned from the file header [hdr].
* Fails if transcription fails.
*)
let hdr bs0:((elf32_program_header_table_entry)list)error=
(let endian = (get_elf32_header_endianness hdr) in
let pentries = (Uint32_wrapper.to_bigint hdr.elf32_phnum) in
let pentry_size = (Uint32_wrapper.to_bigint hdr.elf32_phentsize) in
let psize = (Nat_big_num.mul pentries pentry_size) in
if Nat_big_num.equal psize( (Nat_big_num.of_int 0)) then
return []
else
let poffset = (Uint32_wrapper.to_bigint hdr.elf32_phoff) in bind (Byte_sequence.offset_and_cut poffset psize bs0) (fun pexact -> bind (
read_elf32_program_header_table psize endian pexact) (fun (pht, _) ->
return pht)))
(** [obtain_elf64_program_header_table hdr bs0] reads a file's program header table
* from byte sequence [bs0] using information gleaned from the file header [hdr].
* Fails if transcription fails.
*)
let hdr bs0:((elf64_program_header_table_entry)list)error=
(let endian = (get_elf64_header_endianness hdr) in
let pentries = (Uint32_wrapper.to_bigint hdr.elf64_phnum) in
let pentry_size = (Uint32_wrapper.to_bigint hdr.elf64_phentsize) in
let psize = (Nat_big_num.mul pentries pentry_size) in
if Nat_big_num.equal psize( (Nat_big_num.of_int 0)) then
return []
else
let poffset = (Uint64_wrapper.to_bigint hdr.elf64_phoff) in bind (Byte_sequence.offset_and_cut poffset psize bs0) (fun pexact -> bind (
read_elf64_program_header_table psize endian pexact) (fun (pht, _) ->
return pht)))
(** [obtain_elf32_section_header_table hdr bs0] reads a file's section header table
* from byte sequence [bs0] using information gleaned from the file header [hdr].
* Fails if transcription fails.
*)
let hdr bs0:((elf32_section_header_table_entry)list)error=
(let endian = (get_elf32_header_endianness hdr) in
let sentries = (Uint32_wrapper.to_bigint hdr.elf32_shnum) in
let sentry_size = (Uint32_wrapper.to_bigint hdr.elf32_shentsize) in
let ssize = (Nat_big_num.mul sentries sentry_size) in
if Nat_big_num.equal ssize( (Nat_big_num.of_int 0)) then
return []
else
let soffset = (Uint32_wrapper.to_bigint hdr.elf32_shoff) in bind (Byte_sequence.offset_and_cut soffset ssize bs0) (fun sexact -> bind (
read_elf32_section_header_table ssize endian sexact) (fun (sht, _) ->
return sht)))
(** [obtain_elf64_section_header_table hdr bs0] reads a file's section header table
* from byte sequence [bs0] using information gleaned from the file header [hdr].
* Fails if transcription fails.
*)
let hdr bs0:((elf64_section_header_table_entry)list)error=
(let endian = (get_elf64_header_endianness hdr) in
let sentries = (Uint32_wrapper.to_bigint hdr.elf64_shnum) in
let sentry_size = (Uint32_wrapper.to_bigint hdr.elf64_shentsize) in
let ssize = (Nat_big_num.mul sentries sentry_size) in
if Nat_big_num.equal ssize( (Nat_big_num.of_int 0)) then
return []
else
let soffset = (Uint64_wrapper.to_bigint hdr.elf64_shoff) in bind (Byte_sequence.offset_and_cut soffset ssize bs0) (fun sexact -> bind (
read_elf64_section_header_table ssize endian sexact) (fun (sht, _) ->
return sht)))
(** [obtain_elf32_section_header_string_table hdr sht bs0] reads a file's section
* header string table from byte sequence [bs0] using information gleaned from
* the file header [hdr] and section header table [sht].
* Fails if transcription fails.
*)
let hdr sht bs0:((string_table)option)error=
(if Nat_big_num.equal (Uint32_wrapper.to_bigint hdr.elf32_shstrndx) shn_undef then
return None
else bind (match Ml_bindings.list_index_big_int (Uint32_wrapper.to_bigint hdr.elf32_shstrndx) sht with
None -> fail "no section header string table"
| Some x -> return x
) (fun sh -> bind (Byte_sequence.offset_and_cut (Uint32_wrapper.to_bigint sh.elf32_sh_offset) (Uint32_wrapper.to_bigint sh.elf32_sh_size) bs0) (fun sexact ->
return (Some (string_table_of_byte_sequence sexact)))))
(** [obtain_elf64_section_header_string_table hdr sht bs0] reads a file's section
* header string table from byte sequence [bs0] using information gleaned from
* the file header [hdr] and section header table [sht].
* Fails if transcription fails.
*)
let hdr sht bs0:((string_table)option)error=
(if Nat_big_num.equal (Uint32_wrapper.to_bigint hdr.elf64_shstrndx) shn_undef then
return None
else bind (match Ml_bindings.list_index_big_int (Uint32_wrapper.to_bigint hdr.elf64_shstrndx) sht with
None -> fail "no section header string table"
| Some x -> return x
) (fun sh -> bind (Byte_sequence.offset_and_cut (Uint64_wrapper.to_bigint sh.elf64_sh_offset) (Ml_bindings.nat_big_num_of_uint64 sh.elf64_sh_size) bs0) (fun sexact ->
return (Some (string_table_of_byte_sequence sexact)))))
(** [obtain_elf32_interpreted_segments pht bs0] generates the interpreted segments
* of an ELF file from the uninterpreted program header table entries in [pht],
* read from byte sequence [bs0]. Makes working with segments easier.
* May fail if transcription of any segment fails.
*)
let obtain_elf32_interpreted_segments pht bdy:((elf32_interpreted_segment)list)error=
(mapM (fun ph ->
let offset = (Uint32_wrapper.to_bigint ph.elf32_p_offset) in
let size2 = (Uint32_wrapper.to_bigint ph.elf32_p_filesz) in bind (if Nat_big_num.equal size2( (Nat_big_num.of_int 0)) then
return Byte_sequence.empty
else
Byte_sequence.offset_and_cut offset size2 bdy) (fun relevant ->
let vaddr = (Uint32_wrapper.to_bigint ph.elf32_p_vaddr) in
let paddr = (Uint32_wrapper.to_bigint ph.elf32_p_paddr) in
let memsz = (Uint32_wrapper.to_bigint ph.elf32_p_memsz) in
let typ = (Uint32_wrapper.to_bigint ph.elf32_p_type) in
let align = (Uint32_wrapper.to_bigint ph.elf32_p_align) in
let flags = (parse_elf_segment_permissions (Uint32_wrapper.to_bigint ph.elf32_p_flags)) in
if Nat_big_num.less memsz size2 then
fail "obtain_elf32_interpreted_segments: memory size of segment cannot be less than file size"
else
return { elf32_segment_body = relevant; elf32_segment_type = typ;
elf32_segment_size = size2; elf32_segment_memsz = memsz;
elf32_segment_base = vaddr; elf32_segment_flags = flags;
elf32_segment_paddr = paddr; elf32_segment_align = align;
elf32_segment_offset = offset })
) pht)
(** [obtain_elf64_interpreted_segments pht bs0] generates the interpreted segments
* of an ELF file from the uninterpreted program header table entries in [pht],
* read from byte sequence [bs0]. Makes working with segments easier.
* May fail if transcription of any segment fails.
*)
let obtain_elf64_interpreted_segments pht bdy:((elf64_interpreted_segment)list)error=
(mapM (fun ph ->
let offset = (Uint64_wrapper.to_bigint ph.elf64_p_offset) in
let size2 = (Ml_bindings.nat_big_num_of_uint64 ph.elf64_p_filesz) in bind (if Nat_big_num.equal size2( (Nat_big_num.of_int 0)) then
return Byte_sequence.empty
else
Byte_sequence.offset_and_cut offset size2 bdy) (fun relevant ->
let vaddr = (Ml_bindings.nat_big_num_of_uint64 ph.elf64_p_vaddr) in
let paddr = (Ml_bindings.nat_big_num_of_uint64 ph.elf64_p_paddr) in
let memsz = (Ml_bindings.nat_big_num_of_uint64 ph.elf64_p_memsz) in
let typ = (Uint32_wrapper.to_bigint ph.elf64_p_type) in
let align = (Ml_bindings.nat_big_num_of_uint64 ph.elf64_p_align) in
let flags = (parse_elf_segment_permissions (Uint32_wrapper.to_bigint ph.elf64_p_flags)) in
return { elf64_segment_body = relevant; elf64_segment_type = typ;
elf64_segment_size = size2; elf64_segment_memsz = memsz;
elf64_segment_base = vaddr; elf64_segment_flags = flags;
elf64_segment_align = align; elf64_segment_paddr = paddr;
elf64_segment_offset = offset })
) pht)
(** [obtain_elf32_interpreted_section sht bs0] generates the interpreted sections
* of an ELF file from the uninterpreted section header table entries in [sht],
* read from byte sequence [bs0]. Makes working with sections easier.
* May fail if transcription of any section fails.
*)
let obtain_elf32_interpreted_sections shstrtab sht bs0:((elf32_interpreted_section)list)error=
(mapM (fun sh ->
let offset = (Uint32_wrapper.to_bigint sh.elf32_sh_offset) in
let size2 = (Uint32_wrapper.to_bigint sh.elf32_sh_size) in
let name1 = (Uint32_wrapper.to_bigint sh.elf32_sh_name) in
let typ = (Uint32_wrapper.to_bigint sh.elf32_sh_type) in
let filesz = (if Nat_big_num.equal typ sht_nobits then (Nat_big_num.of_int 0) else size2) in
let flags = (Uint32_wrapper.to_bigint sh.elf32_sh_flags) in
let base = (Uint32_wrapper.to_bigint sh.elf32_sh_addr) in
let link1 = (Uint32_wrapper.to_bigint sh.elf32_sh_link) in
let info = (Uint32_wrapper.to_bigint sh.elf32_sh_info) in
let align = (Uint32_wrapper.to_bigint sh.elf32_sh_addralign) in
let entry_size = (Uint32_wrapper.to_bigint sh.elf32_sh_entsize) in
let name_string =
((match shstrtab with
None -> ""
| Some shstrtab ->
(match (get_string_at name1 shstrtab) with
| Success n -> n
| Fail _ -> ""
)
))
in bind (if Nat_big_num.equal filesz( (Nat_big_num.of_int 0)) then
return Byte_sequence.empty
else
Byte_sequence.offset_and_cut offset filesz bs0) (fun relevant ->
return { elf32_section_name = name1; elf32_section_type = typ;
elf32_section_size = size2; elf32_section_offset = offset;
elf32_section_flags = flags; elf32_section_addr = base;
elf32_section_link = link1; elf32_section_info = info;
elf32_section_align = align; elf32_section_body = relevant;
elf32_section_entsize = entry_size;
elf32_section_name_as_string = name_string })
) sht)
(** [obtain_elf64_interpreted_section sht bs0] generates the interpreted sections
* of an ELF file from the uninterpreted section header table entries in [sht],
* read from byte sequence [bs0]. Makes working with sections easier.
* May fail if transcription of any section fails.
*)
let obtain_elf64_interpreted_sections shstrtab sht bs0:((elf64_interpreted_section)list)error=
(mapM (fun sh ->
let offset = (Uint64_wrapper.to_bigint sh.elf64_sh_offset) in
let size2 = (Ml_bindings.nat_big_num_of_uint64 sh.elf64_sh_size) in
let name1 = (Uint32_wrapper.to_bigint sh.elf64_sh_name) in
let typ = (Uint32_wrapper.to_bigint sh.elf64_sh_type) in
let filesz = (if Nat_big_num.equal typ sht_nobits then (Nat_big_num.of_int 0) else size2) in
let flags = (Ml_bindings.nat_big_num_of_uint64 sh.elf64_sh_flags) in
let base = (Ml_bindings.nat_big_num_of_uint64 sh.elf64_sh_addr) in
let link1 = (Uint32_wrapper.to_bigint sh.elf64_sh_link) in
let info = (Uint32_wrapper.to_bigint sh.elf64_sh_info) in
let align = (Ml_bindings.nat_big_num_of_uint64 sh.elf64_sh_addralign) in
let entry_size = (Ml_bindings.nat_big_num_of_uint64 sh.elf64_sh_entsize) in
let name_string =
((match shstrtab with
None -> ""
| Some shstrtab ->
(match (get_string_at name1 shstrtab) with
| Success n -> n
| Fail _ -> ""
)
))
in bind (if Nat_big_num.equal filesz( (Nat_big_num.of_int 0)) then
return Byte_sequence.empty
else
Byte_sequence.offset_and_cut offset filesz bs0) (fun relevant ->
return { elf64_section_name = name1; elf64_section_type = typ;
elf64_section_size = size2; elf64_section_offset = offset;
elf64_section_flags = flags; elf64_section_addr = base;
elf64_section_link = link1; elf64_section_info = info;
elf64_section_align = align; elf64_section_body = relevant;
elf64_section_entsize = entry_size;
elf64_section_name_as_string = name_string })
) sht)
(** [find_first_not_in_range e rngs] for every pair (start, end) in [rngs], finds
* the first element, beginning counting from [e], that does not lie between
* a start and end value.
*)
let rec find_first_not_in_range start ranges:Nat_big_num.num=
((match List.filter (fun (x, y) -> Nat_big_num.greater_equal start x && Nat_big_num.less_equal start y) ranges with
| [] -> start
| _ -> find_first_not_in_range ( Nat_big_num.add start( (Nat_big_num.of_int 1))) ranges
))
(** [find_first_in_range e rngs] for every pair (start, end) in [rngs], finds
* the first element, beginning counting from [e], that lies between
* a start and end value.
*)
let rec find_first_in_range start ranges:Nat_big_num.num=
((match List.filter (fun (x, y) -> Nat_big_num.greater_equal start x && Nat_big_num.less_equal start y) ranges with
| [] -> find_first_in_range ( Nat_big_num.add start( (Nat_big_num.of_int 1))) ranges
| _ -> start
))
(** [compute_differences start max ranges] is a utility function used for calculating
* "dead" spots in an ELF file not covered by any of the interpreted structure
* that nevertheless need recording in the bits_and_bobs field of each ELF record
* in order to maintain in-out roundtripping up to exact binary equivalence.
*)
let rec compute_differences start max ranges:((Nat_big_num.num*Nat_big_num.num)list)error=
(if Nat_big_num.equal start max then
return []
else if Nat_big_num.greater start max then
fail "compute_differences: passed maximum"
else
let first = (find_first_not_in_range start ranges) in
if Nat_big_num.greater_equal first max then
return []
else
let last1 = (find_first_in_range first ranges) in
if Nat_big_num.greater last1 max then
return [(first, max)]
else bind (compute_differences last1 max ranges) (fun tail ->
return ((first, last1)::tail)))
(** [obtain_elf32_bits_and_bobs hdr pht segs sht sects bs0] identifies and records
* the "dead" spots of an ELF file not covered by any meaningful structure of the
* ELF file format.
*)
let obtain_elf32_bits_and_bobs hdr segs interp_segs sects interp_sects bs0:((Nat_big_num.num*Byte_sequence_wrapper.byte_sequence)list)error=
(let hdr_off_len = ( (Nat_big_num.of_int 0), Uint32_wrapper.to_bigint hdr.elf32_ehsize) in
let pht_off = (Uint32_wrapper.to_bigint hdr.elf32_phoff) in
let pht_len = (Nat_big_num.mul (Uint32_wrapper.to_bigint hdr.elf32_phentsize) (Uint32_wrapper.to_bigint hdr.elf32_phnum)) in
let pht_off_len = (pht_off, Nat_big_num.add pht_off pht_len) in
let sht_off = (Uint32_wrapper.to_bigint hdr.elf32_shoff) in
let sht_len = (Nat_big_num.mul (Uint32_wrapper.to_bigint hdr.elf32_shentsize) (Uint32_wrapper.to_bigint hdr.elf32_shnum)) in
let sht_off_len = (sht_off, Nat_big_num.add sht_off sht_len) in
if List.length interp_segs = List.length segs then
let seg_zip = (Lem_list.list_combine segs interp_segs) in
if List.length interp_sects = List.length sects then
let sect_zip = (Lem_list.list_combine sects interp_sects) in
let seg_off_len =
(Lem_list.map (fun (seg, interp_seg) ->
let start = (Uint32_wrapper.to_bigint seg.elf32_p_offset) in
let len = (interp_seg.elf32_segment_size) in
(start, Nat_big_num.add start len)) seg_zip)
in
let sect_off_len =
(Lem_list.map (fun (sect, interp_sect) ->
let start = (Uint32_wrapper.to_bigint sect.elf32_sh_offset) in
let len = (interp_sect.elf32_section_size) in
(start, Nat_big_num.add start len)) sect_zip)
in
let pre_layout = (hdr_off_len :: (pht_off_len :: (sht_off_len :: List.rev_append (List.rev seg_off_len) sect_off_len))) in
let layout =
(List.sort (fun (off_x, _) (off_y, _) ->
Nat_big_num.compare off_x off_y
) pre_layout)
in bind (compute_differences( (Nat_big_num.of_int 0)) (Byte_sequence.length0 bs0) layout) (fun diffs ->
mapM (fun (start, len) -> bind (Byte_sequence.offset_and_cut start ( Nat_big_num.sub_nat len start) bs0) (fun rel ->
return (start, rel))
) diffs)
else
fail "obtain_elf32_bits_and_bobs: section header table and interpreted section differ in length"
else
fail "obtain_elf32_bits_and_bobs: program header table and interpreted segments differ in length")
(** [obtain_elf64_bits_and_bobs hdr pht segs sht sects bs0] identifies and records
* the "dead" spots of an ELF file not covered by any meaningful structure of the
* ELF file format.
*)
let obtain_elf64_bits_and_bobs hdr segs interp_segs sects interp_sects bs0:((Nat_big_num.num*Byte_sequence_wrapper.byte_sequence)list)error=
(let hdr_off_len = ( (Nat_big_num.of_int 0), Uint32_wrapper.to_bigint hdr.elf64_ehsize) in
let pht_off = (Uint64_wrapper.to_bigint hdr.elf64_phoff) in
let pht_len = (Nat_big_num.mul (Uint32_wrapper.to_bigint hdr.elf64_phentsize) (Uint32_wrapper.to_bigint hdr.elf64_phnum)) in
let pht_off_len = (pht_off, Nat_big_num.add pht_off pht_len) in
let sht_off = (Uint64_wrapper.to_bigint hdr.elf64_shoff) in
let sht_len = (Nat_big_num.mul (Uint32_wrapper.to_bigint hdr.elf64_shentsize) (Uint32_wrapper.to_bigint hdr.elf64_shnum)) in
let sht_off_len = (sht_off, Nat_big_num.add sht_off sht_len) in
if List.length interp_segs = List.length segs then
let seg_zip = (Lem_list.list_combine segs interp_segs) in
if List.length interp_sects = List.length sects then
let sect_zip = (Lem_list.list_combine sects interp_sects) in
let seg_off_len =
(Lem_list.map (fun (seg, interp_seg) ->
let start = (Uint64_wrapper.to_bigint seg.elf64_p_offset) in
let len = (interp_seg.elf64_segment_size) in
(start, Nat_big_num.add start len)) seg_zip)
in
let sect_off_len =
(Lem_list.map (fun (sect, interp_sect) ->
let start = (Uint64_wrapper.to_bigint sect.elf64_sh_offset) in
let len = (interp_sect.elf64_section_size) in
(start, Nat_big_num.add start len)) sect_zip)
in
let pre_layout = (hdr_off_len :: (pht_off_len :: (sht_off_len :: List.rev_append (List.rev seg_off_len) sect_off_len))) in
let layout =
(List.sort (fun (off_x, _) (off_y, _) ->
Nat_big_num.compare off_x off_y
) pre_layout)
in bind (compute_differences( (Nat_big_num.of_int 0)) (Byte_sequence.length0 bs0) layout) (fun diffs ->
mapM (fun (start, finish) -> bind (Byte_sequence.offset_and_cut start ( Nat_big_num.sub_nat finish start) bs0) (fun rel ->
return (start, rel))
) diffs)
else
fail "obtain_elf64_bits_and_bobs: section header table and interpreted section differ in length"
else
fail "obtain_elf64_bits_and_bobs: program header table and interpreted segments differ in length")
(** [read_elf32_file bs0] reads an ELF32 file from byte sequence [bs0]. Fails if
* transcription fails.
*)
let read_elf32_file bs0:(elf32_file)error= (bind (read_elf32_header bs0) (fun (hdr, bs1) -> bind (obtain_elf32_program_header_table hdr bs0) (fun pht -> bind (obtain_elf32_section_header_table hdr bs0) (fun sht -> bind (obtain_elf32_section_header_string_table hdr sht bs0) (fun shstrtab -> bind (obtain_elf32_interpreted_segments pht bs0) (fun segs -> bind (obtain_elf32_interpreted_sections shstrtab sht bs0) (fun sects -> bind (obtain_elf32_bits_and_bobs hdr pht segs sht sects bs0) (fun bits_and_bobs ->
return { elf32_file_header = hdr;
elf32_file_program_header_table = pht;
elf32_file_section_header_table = sht;
elf32_file_interpreted_segments = segs;
elf32_file_interpreted_sections = sects;
elf32_file_bits_and_bobs = bits_and_bobs }))))))))
(** [read_elf64_file bs0] reads an ELF64 file from byte sequence [bs0]. Fails if
* transcription fails.
*)
let read_elf64_file bs0:(elf64_file)error= (bind (read_elf64_header bs0) (fun (hdr, bs1) -> bind (obtain_elf64_program_header_table hdr bs0) (fun pht -> bind (obtain_elf64_section_header_table hdr bs0) (fun sht -> bind (obtain_elf64_section_header_string_table hdr sht bs0) (fun shstrtab -> bind (obtain_elf64_interpreted_segments pht bs0) (fun segs -> bind (obtain_elf64_interpreted_sections shstrtab sht bs0) (fun sects -> bind (obtain_elf64_bits_and_bobs hdr pht segs sht sects bs0) (fun bits_and_bobs ->
return { elf64_file_header = hdr;
elf64_file_program_header_table = pht;
elf64_file_section_header_table = sht;
elf64_file_interpreted_segments = segs;
elf64_file_interpreted_sections = sects;
elf64_file_bits_and_bobs = bits_and_bobs }))))))))
(** [get_elf32_file_secton_header_string_table f1] returns the ELF file, [f1],
* section header string table.
* TODO: why is this not using obtain_elf32_section_header_string_table above?
*)
let f3:(string_table)error=
(let hdr = (f3.elf32_file_header) in
let sht = (f3.elf32_file_section_header_table) in
let segs = (f3.elf32_file_interpreted_segments) in
let idx1 = (Uint32_wrapper.to_bigint hdr.elf32_shstrndx) in bind (bytes_of_elf32_file f3) (fun bs0 ->
(match Ml_bindings.list_index_big_int idx1 sht with
| None -> fail "obtain_elf32_string_table: invalid offset into section header table"
| Some sect ->
let offset = (Uint32_wrapper.to_bigint sect.elf32_sh_offset) in
let size2 = (Uint32_wrapper.to_bigint sect.elf32_sh_size) in bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun rel ->
let strings = (Byte_sequence.string_of_byte_sequence rel) in
return (String_table.mk_string_table strings Missing_pervasives.null_char))
)))
(** [get_elf64_file_secton_header_string_table f1] returns the ELF file, [f1],
* section header string table.
* TODO: why is this not using obtain_elf64_section_header_string_table above?
*)
let f3:(string_table)error=
(let hdr = (f3.elf64_file_header) in
let sht = (f3.elf64_file_section_header_table) in
let segs = (f3.elf64_file_interpreted_segments) in
let idx1 = (Uint32_wrapper.to_bigint hdr.elf64_shstrndx) in bind (bytes_of_elf64_file f3) (fun bs0 ->
(match Ml_bindings.list_index_big_int idx1 sht with
| None -> fail "obtain_elf64_string_table: invalid offset into section header table"
| Some sect ->
let offset = (Uint64_wrapper.to_bigint sect.elf64_sh_offset) in
let size2 = (Ml_bindings.nat_big_num_of_uint64 sect.elf64_sh_size) in bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun rel ->
let strings = (Byte_sequence.string_of_byte_sequence rel) in
return (String_table.mk_string_table strings Missing_pervasives.null_char))
)))
let find_elf32_symbols_by_symtab_idx sec_idx f:((elf32_symbol_table_entry)list*string_table*Nat_big_num.num)error= (bind (match Lem_list.list_index f.elf32_file_interpreted_sections (Nat_big_num.to_int sec_idx) with
None -> fail "impossible: interpreted section found but not indexable"
| Some sec -> return sec
) (fun sec -> bind (match Lem_list.list_index f.elf32_file_interpreted_sections (Nat_big_num.to_int sec.elf32_section_link) with
None -> fail "no associated strtab"
| Some strs -> return strs
) (fun strs ->
let strings = (Byte_sequence.string_of_byte_sequence strs.elf32_section_body) in
let strtab = (String_table.mk_string_table strings null_char) in
let endian = (get_elf32_header_endianness f.elf32_file_header) in bind (read_elf32_symbol_table endian sec.elf32_section_body) (fun symtab ->
return (symtab, strtab, sec_idx)))))
let find_elf32_symtab_by_type t f:(elf32_symbol_table*string_table*Nat_big_num.num)error=
(let found_symtab_index = (find_index0 (fun sh -> Nat_big_num.equal sh.elf32_section_type t) f.elf32_file_interpreted_sections) in bind (match found_symtab_index with
None -> fail "no such symtab"
| Some sec_idx -> return sec_idx
) (fun sec_idx -> find_elf32_symbols_by_symtab_idx sec_idx f))
let find_elf64_symbols_by_symtab_idx sec_idx f:((elf64_symbol_table_entry)list*string_table*Nat_big_num.num)error= (bind (match Lem_list.list_index f.elf64_file_interpreted_sections (Nat_big_num.to_int sec_idx) with
None -> fail "impossible: interpreted section found but not indexable"
| Some sec -> return sec
) (fun sec -> bind (match Lem_list.list_index f.elf64_file_interpreted_sections (Nat_big_num.to_int sec.elf64_section_link) with
None -> fail "no associated strtab"
| Some strs -> return strs
) (fun strs ->
let strings = (Byte_sequence.string_of_byte_sequence strs.elf64_section_body) in
let strtab = (String_table.mk_string_table strings null_char) in
let endian = (get_elf64_header_endianness f.elf64_file_header) in bind (read_elf64_symbol_table endian sec.elf64_section_body) (fun symtab ->
return (symtab, strtab, sec_idx)))))
let find_elf64_symtab_by_type t f:(elf64_symbol_table*string_table*Nat_big_num.num)error=
(let found_symtab_index = (find_index0 (fun sh -> Nat_big_num.equal sh.elf64_section_type t) f.elf64_file_interpreted_sections) in bind (match found_symtab_index with
None -> fail "no such symtab"
| Some sec_idx -> return sec_idx
) (fun sec_idx -> find_elf64_symbols_by_symtab_idx sec_idx f))
(** [get_elf32_file_symbol_string_table f1] returns the ELF file [f1] symbol
* string table. May fail.
*)
let get_elf32_file_symbol_string_table f3:(string_table)error=
(let hdr = (f3.elf32_file_header) in
let sht = (f3.elf32_file_section_header_table) in
let segs = (f3.elf32_file_interpreted_segments) in
let strtabs = (Missing_pervasives.mapMaybei (fun index sect ->
if Nat_big_num.equal (Uint32_wrapper.to_bigint sect.elf32_sh_type) sht_strtab then
if Nat_big_num.equal index (Uint32_wrapper.to_bigint hdr.elf32_shstrndx) then
None
else
Some sect
else
None) sht)
in bind (bytes_of_elf32_file f3) (fun bs0 ->
bind (mapM (fun sect ->
let offset = (Uint32_wrapper.to_bigint sect.elf32_sh_offset) in
let size2 = (Uint32_wrapper.to_bigint sect.elf32_sh_size) in bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun bs1 ->
let strings = (Byte_sequence.string_of_byte_sequence bs1) in
return (String_table.mk_string_table strings Missing_pervasives.null_char))) strtabs) (fun strings ->
String_table.concat0 strings)))
(** [get_elf64_file_symbol_string_table f1] returns the ELF file [f1] symbol
* string table. May fail.
*)
let get_elf64_file_symbol_string_table f3:(string_table)error=
(let hdr = (f3.elf64_file_header) in
let sht = (f3.elf64_file_section_header_table) in
let segs = (f3.elf64_file_interpreted_segments) in
let strtabs = (Missing_pervasives.mapMaybei (fun index sect ->
if Nat_big_num.equal (Uint32_wrapper.to_bigint sect.elf64_sh_type) sht_strtab then
if false then
None
else
Some sect
else
None) sht)
in bind (bytes_of_elf64_file f3) (fun bs0 ->
bind (mapM (fun sect ->
let offset = (Uint64_wrapper.to_bigint sect.elf64_sh_offset) in
let size2 = (Ml_bindings.nat_big_num_of_uint64 sect.elf64_sh_size) in bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun bs1 ->
let strings = (Byte_sequence.string_of_byte_sequence bs1) in
return (String_table.mk_string_table strings Missing_pervasives.null_char))) strtabs) (fun strings ->
String_table.concat0 strings)))
(** [get_elf32_file_string_table_by_index f1 index] returns the ELF file [f1]
* string table that is pointed to by the section header table entry at index
* [index]. May fail if index is out of range, or otherwise.
*)
let get_elf32_string_table_by_index ef link1:(string_table)error=
(let hdr = (ef.elf32_file_header) in
let sht = (ef.elf32_file_section_header_table) in
let sects = (ef.elf32_file_interpreted_sections) in
(match Lem_list.list_index sects (Nat_big_num.to_int link1) with
| None -> fail "get_elf32_string_table_by_index: invalid index"
| Some sym1 -> return (mk_string_table (Byte_sequence.string_of_byte_sequence sym1.elf32_section_body) Missing_pervasives.null_char)
))
(** [get_elf64_file_string_table_by_index f1 index] returns the ELF file [f1]
* string table that is pointed to by the section header table entry at index
* [index]. May fail if index is out of range, or otherwise.
*)
let get_elf64_string_table_by_index ef link1:(string_table)error=
(let hdr = (ef.elf64_file_header) in
let sht = (ef.elf64_file_section_header_table) in
let sects = (ef.elf64_file_interpreted_sections) in
(match Lem_list.list_index sects (Nat_big_num.to_int link1) with
| None -> fail "get_elf64_string_table_by_index: invalid index"
| Some sym1 -> return (mk_string_table (Byte_sequence.string_of_byte_sequence sym1.elf64_section_body) Missing_pervasives.null_char)
))
(** [get_elf32_file_symbol_table f1] returns the ELF file [f1] symbol
* table. May fail.
*)
let get_elf32_file_symbol_table f3:((elf32_symbol_table_entry)list)error=
(let hdr = (f3.elf32_file_header) in
let sht = (f3.elf32_file_section_header_table) in
let segs = (f3.elf32_file_interpreted_segments) in
let endian = (get_elf32_header_endianness hdr) in
let symtabs = (List.filter (fun sect -> Nat_big_num.equal
(Uint32_wrapper.to_bigint sect.elf32_sh_type) sht_symtab
) sht)
in
(match symtabs with
| [] -> return []
| [symtab] ->
let offset = (Uint32_wrapper.to_bigint symtab.elf32_sh_offset) in
let size2 = (Uint32_wrapper.to_bigint symtab.elf32_sh_size) in bind (bytes_of_elf32_file f3) (fun bs0 -> bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun relevant ->
read_elf32_symbol_table endian relevant))
| _ ->
fail "obtain_elf32_symbol_table: an ELF file may only have one symbol table of type SHT_SYMTAB"
))
(** [get_elf64_file_symbol_table f1] returns the ELF file [f1] symbol
* table. May fail.
*)
let get_elf64_file_symbol_table f3:((elf64_symbol_table_entry)list*string_table)error=
(let hdr = (f3.elf64_file_header) in
let sht = (f3.elf64_file_section_header_table) in
let segs = (f3.elf64_file_interpreted_segments) in
let endian = (get_elf64_header_endianness hdr) in
let symtabs = (List.filter (fun sect -> Nat_big_num.equal
(Uint32_wrapper.to_bigint sect.elf64_sh_type) sht_symtab
) sht)
in
(match symtabs with
| [] -> return ([],String_table.dummy_strtab)
| [symtab] ->
let lnk = (Uint32_wrapper.to_bigint symtab.elf64_sh_link) in bind (get_elf64_string_table_by_index f3 lnk) (fun strtab ->
let offset = (Uint64_wrapper.to_bigint symtab.elf64_sh_offset) in
let size2 = (Ml_bindings.nat_big_num_of_uint64 symtab.elf64_sh_size) in bind (bytes_of_elf64_file f3) (fun bs0 -> bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun relevant -> bind (read_elf64_symbol_table endian relevant) (fun symtab ->
return (symtab,strtab)))))
| _ ->
fail "obtain_elf64_symbol_table: an ELF file may only have one symbol table of type SHT_SYMTAB"
))
(** [get_elf32_file_dynamic_symbol_table f1] returns the ELF file [f1] dynamic
* symbol table. May fail.
*)
let get_elf32_file_dynamic_symbol_table ef:((elf32_symbol_table_entry)list)error=
(let hdr = (ef.elf32_file_header) in
let sht = (ef.elf32_file_section_header_table) in
let segs = (ef.elf32_file_interpreted_segments) in
let endian = (get_elf32_header_endianness hdr) in
let symtabs = (List.filter (fun sect -> Nat_big_num.equal
(Uint32_wrapper.to_bigint sect.elf32_sh_type) sht_dynsym
) sht)
in
(match symtabs with
| [] -> return []
| [symtab] ->
let offset = (Uint32_wrapper.to_bigint symtab.elf32_sh_offset) in
let size2 = (Uint32_wrapper.to_bigint symtab.elf32_sh_size) in bind (bytes_of_elf32_file ef) (fun bs0 -> bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun relevant ->
read_elf32_symbol_table endian relevant))
| _ ->
fail "obtain_elf32_dynamic_symbol_table: an ELF file may only have one symbol table of type SHT_DYNSYM"
))
(** [get_elf64_file_dynamic_symbol_table f1] returns the ELF file [f1] dynamic
* symbol table. May fail.
*)
let get_elf64_file_dynamic_symbol_table ef:((elf64_symbol_table_entry)list)error=
(let hdr = (ef.elf64_file_header) in
let sht = (ef.elf64_file_section_header_table) in
let segs = (ef.elf64_file_interpreted_segments) in
let endian = (get_elf64_header_endianness hdr) in
let symtabs = (List.filter (fun sect -> Nat_big_num.equal
(Uint32_wrapper.to_bigint sect.elf64_sh_type) sht_dynsym
) sht)
in
(match symtabs with
| [] -> return []
| [symtab] ->
let offset = (Uint64_wrapper.to_bigint symtab.elf64_sh_offset) in
let size2 = (Ml_bindings.nat_big_num_of_uint64 symtab.elf64_sh_size) in bind (bytes_of_elf64_file ef) (fun bs0 -> bind (Byte_sequence.offset_and_cut offset size2 bs0) (fun relevant ->
read_elf64_symbol_table endian relevant))
| _ ->
fail "obtain_elf64_dynamic_symbol_table: an ELF file may only have one symbol table of type SHT_DYNSYM"
))
(** [get_elf32_file_symbol_table_by_index f1 index] returns the ELF file [f1]
* symbol table that is pointed to by the section header table entry at index
* [index]. May fail if index is out of range, or otherwise.
*)
let get_elf32_symbol_table_by_index ef link1:(elf32_symbol_table)error=
(let hdr = (ef.elf32_file_header) in
let sht = (ef.elf32_file_section_header_table) in
let sects = (ef.elf32_file_interpreted_sections) in
let endian = (get_elf32_header_endianness hdr) in
(match Lem_list.list_index sects (Nat_big_num.to_int link1) with
| None -> fail "get_elf32_symbol_table_by_index: invalid index"
| Some sym1 ->
read_elf32_symbol_table endian sym1.elf32_section_body
))
(** [get_elf64_file_symbol_table_by_index f1 index] returns the ELF file [f1]
* symbol table that is pointed to by the section header table entry at index
* [index]. May fail if index is out of range, or otherwise.
*)
let get_elf64_symbol_table_by_index ef link1:(elf64_symbol_table)error=
(let hdr = (ef.elf64_file_header) in
let sht = (ef.elf64_file_section_header_table) in
let sects = (ef.elf64_file_interpreted_sections) in
let endian = (get_elf64_header_endianness hdr) in
(match Lem_list.list_index sects (Nat_big_num.to_int link1) with
| None -> fail "get_elf64_symbol_table_by_index: invalid index"
| Some sym1 ->
read_elf64_symbol_table endian sym1.elf64_section_body
))
(** [segment_provenance] records whether a segment that appears in an executable
* process image has been derived directly from an ELF file, or was automatically
* created when the image calculation process noticed a segment with a memory
* size greater than its file size.
* Really a PPCMemism and not strictly needed for the ELF model itself.
*)
type segment_provenance
= FromELF (** Segment derived directly from the source ELF file. *)
| AutoGenerated (** Automatically generated during process extraction as memory size is greater than file size. *)
(** [elf32_executable_process_image] is a process image for ELF32 files. Contains
* all that is necessary to load the executable components of an ELF32 file
* and begin execution.
* XXX: (segments, provenance), entry point, machine type
*)
type elf32_executable_process_image =
( (elf32_interpreted_segment * segment_provenance)list * Nat_big_num.num * Nat_big_num.num)
(** [elf64_executable_process_image] is a process image for ELF64 files. Contains
* all that is necessary to load the executable components of an ELF64 file
* and begin execution.
* XXX: (segments, provenance), entry point, machine type
*)
type elf64_executable_process_image =
( (elf64_interpreted_segment * segment_provenance)list * Nat_big_num.num * Nat_big_num.num)
(** [get_elf32_executable_image f1] extracts an executable process image from an
* executable ELF file. May fail if extraction is impossible.
*)
let get_elf32_executable_image f3:((elf32_interpreted_segment*segment_provenance)list*Nat_big_num.num*Nat_big_num.num)error=
(if is_elf32_executable_file f3.elf32_file_header then
let entr = (f3.elf32_file_header.elf32_entry) in
let segs = (f3.elf32_file_interpreted_segments) in
let mach = (f3.elf32_file_header.elf32_machine) in
(match List.filter (fun sg -> Nat_big_num.equal sg.elf32_segment_type elf_pt_load) segs with
| [] -> fail "get_elf32_executable_image: an executable ELF file must have at least one loadable segment"
| load -> bind (mapM (fun sg ->
if Nat_big_num.equal sg.elf32_segment_memsz( (Nat_big_num.of_int 0)) then
return []
else if Nat_big_num.equal sg.elf32_segment_memsz sg.elf32_segment_size then
return [(sg, FromELF)]
else if Nat_big_num.less sg.elf32_segment_size sg.elf32_segment_memsz then
let diff = (Nat_big_num.sub_nat sg.elf32_segment_memsz sg.elf32_segment_size) in
let zeros1 = (Byte_sequence.zeros diff) in
let addr = (Nat_big_num.add sg.elf32_segment_base sg.elf32_segment_size) in
let align = (sg.elf32_segment_align) in
let paddr = (sg.elf32_segment_paddr) in
let seg =
({ elf32_segment_body = zeros1; elf32_segment_type = (sg.elf32_segment_type);
elf32_segment_size = diff; elf32_segment_memsz = diff;
elf32_segment_base = addr; elf32_segment_flags = (sg.elf32_segment_flags);
elf32_segment_align = align; elf32_segment_paddr = paddr;
elf32_segment_offset = (sg.elf32_segment_offset) })
in
return [(sg, FromELF); (seg, AutoGenerated)]
else
fail "get_elf32_executable_image: invariant invalidated") load) (fun bs_base ->
return (List.concat bs_base, Uint32_wrapper.to_bigint entr, Uint32_wrapper.to_bigint mach))
)
else
fail "get_elf32_executable_image: not an ELF executable file")
(** [get_elf64_executable_image f1] extracts an executable process image from an
* executable ELF file. May fail if extraction is impossible.
*)
let get_elf64_executable_image f3:((elf64_interpreted_segment*segment_provenance)list*Nat_big_num.num*Nat_big_num.num)error=
(if is_elf64_executable_file f3.elf64_file_header then
let entr = (f3.elf64_file_header.elf64_entry) in
let segs = (f3.elf64_file_interpreted_segments) in
let mach = (f3.elf64_file_header.elf64_machine) in
(match List.filter (fun sg -> Nat_big_num.equal sg.elf64_segment_type elf_pt_load) segs with
| [] -> fail "get_elf64_executable_image: an executable ELF file must have at least one loadable segment"
| load -> bind (mapM (fun sg ->
if Nat_big_num.equal sg.elf64_segment_memsz( (Nat_big_num.of_int 0)) then
return []
else if Nat_big_num.equal sg.elf64_segment_memsz sg.elf64_segment_size then
return [(sg, FromELF)]
else if Nat_big_num.less sg.elf64_segment_size sg.elf64_segment_memsz then
let diff = (Nat_big_num.sub_nat sg.elf64_segment_memsz sg.elf64_segment_size) in
let zeros1 = (Byte_sequence.zeros diff) in
let addr = (Nat_big_num.add sg.elf64_segment_base sg.elf64_segment_size) in
let align = (sg.elf64_segment_align) in
let paddr = (sg.elf64_segment_paddr) in
let seg =
({ elf64_segment_body = zeros1; elf64_segment_type = (sg.elf64_segment_type);
elf64_segment_size = diff; elf64_segment_memsz = diff;
elf64_segment_base = addr; elf64_segment_flags = (sg.elf64_segment_flags);
elf64_segment_align = align; elf64_segment_paddr = paddr;
elf64_segment_offset = (sg.elf64_segment_offset) })
in
return [(sg, FromELF); (seg, AutoGenerated)]
else
fail "get_elf64_executable_image: invariant invalidated") load) (fun bs_base ->
return (List.concat bs_base, Ml_bindings.nat_big_num_of_uint64 entr, Uint32_wrapper.to_bigint mach))
)
else
fail "elf64_get_executable_image: not an executable ELF file")
(** [global_symbol_init_info] records the name, type, size, address, chunk
* of initialisation data (if relevant for that symbol), and binding, of every
* global symbol in an ELF file.
* Another PPCMemism.
*)
type global_symbol_init_info
= (string * (Nat_big_num.num * Nat_big_num.num * Nat_big_num.num * byte_sequence0 option * Nat_big_num.num)) list
(** [get_elf32_file_global_symbol_init f1] extracts the global symbol init info
* for ELF file [f1]. May fail.
*)
let get_elf32_file_global_symbol_init f3:((string*(Nat_big_num.num*Nat_big_num.num*Nat_big_num.num*(Byte_sequence_wrapper.byte_sequence)option*Nat_big_num.num))list)error=
(if is_elf32_executable_file f3.elf32_file_header then
let segs = (f3.elf32_file_interpreted_segments) in bind (bytes_of_elf32_file f3) (fun bs0 -> bind (get_elf32_file_symbol_table f3) (fun symtab -> bind (get_elf32_file_symbol_string_table f3) (fun strtab -> bind (Elf_symbol_table.get_elf32_symbol_image_address symtab strtab) (fun strs ->
let mapped = (mapM (fun (symbol, (typ, size2, addr, bind1)) ->
if Nat_big_num.equal typ Elf_symbol_table.stt_object then bind (get_elf32_executable_image f3) (fun (img2, entry, mach) ->
let chunks2 =
(List.filter (fun (chunk, _) -> Nat_big_num.greater_equal
addr chunk.elf32_segment_base &&
(if Nat_big_num.greater size2( (Nat_big_num.of_int 0))
then Nat_big_num.less_equal (Nat_big_num.add addr size2) (Nat_big_num.add chunk.elf32_segment_base chunk.elf32_segment_size)
else Nat_big_num.less (Nat_big_num.add addr size2) (Nat_big_num.add chunk.elf32_segment_base chunk.elf32_segment_size))
) img2)
in
(match chunks2 with
| [] -> return (symbol, (typ, size2, addr, None, bind1))
| [(x, _)] ->
let rebase = (Nat_big_num.sub_nat addr x.elf32_segment_base) in bind (Byte_sequence.offset_and_cut rebase size2 x.elf32_segment_body) (fun relevant ->
return (symbol, (typ, size2, addr, Some relevant, bind1)))
| x::xs -> fail "get_elf32_global_symbol_init: invariant failed, global variable appears in multiple segments"
))
else
return (symbol, (typ, size2, addr, None, bind1))) strs)
in
mapped))))
else
fail "get_elf32_file_global_symbol_init: not an executable ELF file")
(** [get_elf64_file_global_symbol_init f1] extracts the global symbol init info
* for ELF file [f1]. May fail.
*)
let get_elf64_file_global_symbol_init f3:((string*(Nat_big_num.num*Nat_big_num.num*Nat_big_num.num*(Byte_sequence_wrapper.byte_sequence)option*Nat_big_num.num))list)error=
(if is_elf64_executable_file f3.elf64_file_header then
let segs = (f3.elf64_file_interpreted_segments) in bind (bytes_of_elf64_file f3) (fun bs0 -> bind (get_elf64_file_symbol_table f3) (fun (symtab,strtab) -> bind (
Elf_symbol_table.get_elf64_symbol_image_address symtab strtab) (fun strs ->
let mapped = (mapM (fun (symbol, (typ, size2, addr, bind1)) ->
if Nat_big_num.equal typ Elf_symbol_table.stt_object then bind (get_elf64_executable_image f3) (fun (img2, entry, mach) ->
let chunks2 =
(List.filter (fun (chunk, _) -> Nat_big_num.greater_equal
addr chunk.elf64_segment_base &&
(if Nat_big_num.greater size2( (Nat_big_num.of_int 0))
then Nat_big_num.less_equal (Nat_big_num.add addr size2) (Nat_big_num.add chunk.elf64_segment_base chunk.elf64_segment_size)
else Nat_big_num.less (Nat_big_num.add addr size2) (Nat_big_num.add chunk.elf64_segment_base chunk.elf64_segment_size))
) img2)
in
(match chunks2 with
| [] -> return (symbol, (typ, size2, addr, None, bind1))
| [(x, _)] ->
let rebase = (Nat_big_num.sub_nat addr x.elf64_segment_base) in bind (Byte_sequence.offset_and_cut rebase size2 x.elf64_segment_body) (fun relevant ->
return (symbol, (typ, size2, addr, Some relevant, bind1)))
| x::xs -> fail "get_elf64_global_symbol_init: invariant failed, global variable appears in multiple segments"
))
else
return (symbol, (typ, size2, addr, None, bind1))) strs)
in
mapped)))
else
fail "get_elf64_global_symbol_init: not an executable ELF file")
(** [string_of_elf32_file hdr_bdl pht_bdl sht_bdl f1] produces a string-based
* representation of ELF file [f1] using ABI-specific print bundles [hdr_bdl],
* [pht_bdl] and [sht_bdl].
*)
let string_of_elf32_file hdr_bdl pht_bdl sht_bdl f3:string=
((match get_elf32_file_section_header_string_table f3 with
| Fail err ->
unlines [
"\nError obtaining ELF section header string table:"
; err
]
| Success strtab ->
unlines [
"\n*Type elf32_file:"
; "**Header:"
; string_of_elf32_header hdr_bdl f3.elf32_file_header
; "**Program header table:"
; string_of_elf32_program_header_table pht_bdl f3.elf32_file_program_header_table
; "**Section header table:"
; string_of_elf32_section_header_table' sht_bdl strtab f3.elf32_file_section_header_table
; "**Bits and bobs (unused junk space):"
; string_of_list
(instance_Show_Show_tup2_dict instance_Show_Show_Num_natural_dict
Byte_sequence_impl.instance_Show_Show_Byte_sequence_impl_byte_sequence_dict) f3.elf32_file_bits_and_bobs
]
))
(** [string_of_elf64_file hdr_bdl pht_bdl sht_bdl f1] produces a string-based
* representation of ELF file [f1] using ABI-specific print bundles [hdr_bdl],
* [pht_bdl] and [sht_bdl].
*)
let string_of_elf64_file hdr_bdl pht_bdl sht_bdl f3:string=
((match get_elf64_file_section_header_string_table f3 with
| Fail err ->
unlines [
"\nError obtaining ELF section header string table:"
; err
]
| Success strtab ->
unlines [
"\n*Type elf64_file:"
; "**Header:"
; string_of_elf64_header hdr_bdl f3.elf64_file_header
; "**Program header table:"
; string_of_elf64_program_header_table pht_bdl f3.elf64_file_program_header_table
; "**Section header table:"
; string_of_elf64_section_header_table' sht_bdl strtab f3.elf64_file_section_header_table
; "**Bits and bobs (unused junk space):"
; string_of_list
(instance_Show_Show_tup2_dict instance_Show_Show_Num_natural_dict
Byte_sequence_impl.instance_Show_Show_Byte_sequence_impl_byte_sequence_dict) f3.elf64_file_bits_and_bobs
]
))
(** [flag_is_set flag v] checks whether flag [flag] is set in [v].
* TODO: move elsewhere. Check whether this is still being used.
*)
let flag_is_set flag v:bool=
(
Uint64_wrapper.logand
(Uint64_wrapper.of_bigint v)
(Uint64_wrapper.of_bigint flag)
= (Uint64_wrapper.of_bigint flag))