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;;; Guile ELF reader and writer
;; Copyright (C) 2011, 2012, 2013, 2014, 2015 Free Software Foundation, Inc.
;;;; This library is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
;;;; version 3 of the License, or (at your option) any later version.
;;;;
;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;;; Lesser General Public License for more details.
;;;;
;;;; You should have received a copy of the GNU Lesser General Public
;;;; License along with this library; if not, write to the Free Software
;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
;;; Commentary:
;;;
;;; This file was taken from the Guile 2.1 branch, where it is known as
;;; (system vm elf), and renamed to (guix elf). It will be unneeded when Guix
;;; switches to Guile 2.1/2.2.
;;;
;;; A module to read and write Executable and Linking Format (ELF)
;;; files.
;;;
;;; This module exports a number of record types that represent the
;;; various parts that make up ELF files. Fundamentally this is the
;;; main header, the segment headers (program headers), and the section
;;; headers. It also exports bindings for symbolic constants and
;;; utilities to parse and write special kinds of ELF sections.
;;;
;;; See elf(5) for more information on ELF.
;;;
;;; Code:
(define-module (guix elf)
#:use-module (rnrs bytevectors)
#:use-module (system foreign)
#:use-module (system base target)
#:use-module (srfi srfi-9)
#:use-module (ice-9 receive)
#:use-module (ice-9 vlist)
#:export (has-elf-header?
(make-elf* . make-elf)
elf?
elf-bytes elf-word-size elf-byte-order
elf-abi elf-type elf-machine-type
elf-entry elf-phoff elf-shoff elf-flags elf-ehsize
elf-phentsize elf-phnum elf-shentsize elf-shnum elf-shstrndx
ELFOSABI_NONE ELFOSABI_HPUX ELFOSABI_NETBSD ELFOSABI_GNU
ELFOSABI_SOLARIS ELFOSABI_AIX ELFOSABI_IRIX ELFOSABI_FREEBSD
ELFOSABI_TRU64 ELFOSABI_MODESTO ELFOSABI_OPENBSD
ELFOSABI_ARM_AEABI ELFOSABI_ARM ELFOSABI_STANDALONE
ET_NONE ET_REL ET_EXEC ET_DYN ET_CORE
EM_NONE EM_SPARC EM_386 EM_MIPS EM_PPC EM_PPC64 EM_ARM EM_SH
EM_SPARCV9 EM_IA_64 EM_X86_64
elf-header-len elf-header-shoff-offset
write-elf-header
(make-elf-segment* . make-elf-segment)
elf-segment?
elf-segment-index
elf-segment-type elf-segment-offset elf-segment-vaddr
elf-segment-paddr elf-segment-filesz elf-segment-memsz
elf-segment-flags elf-segment-align
elf-program-header-len write-elf-program-header
PT_NULL PT_LOAD PT_DYNAMIC PT_INTERP PT_NOTE PT_SHLIB
PT_PHDR PT_TLS PT_NUM PT_LOOS PT_GNU_EH_FRAME PT_GNU_STACK
PT_GNU_RELRO
PF_R PF_W PF_X
(make-elf-section* . make-elf-section)
elf-section?
elf-section-index
elf-section-name elf-section-type elf-section-flags
elf-section-addr elf-section-offset elf-section-size
elf-section-link elf-section-info elf-section-addralign
elf-section-entsize
elf-section-header-len elf-section-header-addr-offset
elf-section-header-offset-offset
write-elf-section-header
(make-elf-symbol* . make-elf-symbol)
elf-symbol?
elf-symbol-name elf-symbol-value elf-symbol-size
elf-symbol-info elf-symbol-other elf-symbol-shndx
elf-symbol-binding elf-symbol-type elf-symbol-visibility
elf-symbol-len elf-symbol-value-offset write-elf-symbol
SHN_UNDEF
SHT_NULL SHT_PROGBITS SHT_SYMTAB SHT_STRTAB SHT_RELA
SHT_HASH SHT_DYNAMIC SHT_NOTE SHT_NOBITS SHT_REL SHT_SHLIB
SHT_DYNSYM SHT_INIT_ARRAY SHT_FINI_ARRAY SHT_PREINIT_ARRAY
SHT_GROUP SHT_SYMTAB_SHNDX SHT_NUM SHT_LOOS SHT_HIOS
SHT_LOPROC SHT_HIPROC SHT_LOUSER SHT_HIUSER
SHF_WRITE SHF_ALLOC SHF_EXECINSTR SHF_MERGE SHF_STRINGS
SHF_INFO_LINK SHF_LINK_ORDER SHF_OS_NONCONFORMING SHF_GROUP
SHF_TLS
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
DT_BIND_NOW DT_INIT_ARRAY DT_FINI_ARRAY DT_INIT_ARRAYSZ
DT_FINI_ARRAYSZ DT_RUNPATH DT_FLAGS DT_ENCODING
DT_PREINIT_ARRAY DT_PREINIT_ARRAYSZ DT_NUM DT_LOGUILE
DT_GUILE_GC_ROOT DT_GUILE_GC_ROOT_SZ DT_GUILE_ENTRY
DT_GUILE_VM_VERSION DT_GUILE_FRAME_MAPS DT_HIGUILE
DT_LOOS DT_HIOS DT_LOPROC DT_HIPROC
string-table-ref
STB_LOCAL STB_GLOBAL STB_WEAK STB_NUM STB_LOOS STB_GNU
STB_HIOS STB_LOPROC STB_HIPROC
STT_NOTYPE STT_OBJECT STT_FUNC STT_SECTION STT_FILE
STT_COMMON STT_TLS STT_NUM STT_LOOS STT_GNU STT_HIOS
STT_LOPROC STT_HIPROC
STV_DEFAULT STV_INTERNAL STV_HIDDEN STV_PROTECTED
NT_GNU_ABI_TAG NT_GNU_HWCAP NT_GNU_BUILD_ID NT_GNU_GOLD_VERSION
parse-elf
elf-segment elf-segments
elf-section elf-sections elf-section-by-name elf-sections-by-name
elf-symbol-table-len elf-symbol-table-ref
parse-elf-note
elf-note-name elf-note-desc elf-note-type))
;; #define EI_NIDENT 16
;; typedef struct {
;; unsigned char e_ident[EI_NIDENT];
;; uint16_t e_type;
;; uint16_t e_machine;
;; uint32_t e_version;
;; ElfN_Addr e_entry;
;; ElfN_Off e_phoff;
;; ElfN_Off e_shoff;
;; uint32_t e_flags;
;; uint16_t e_ehsize;
;; uint16_t e_phentsize;
;; uint16_t e_phnum;
;; uint16_t e_shentsize;
;; uint16_t e_shnum;
;; uint16_t e_shstrndx;
;; } ElfN_Ehdr;
(define elf32-header-len 52)
(define elf64-header-len 64)
(define (elf-header-len word-size)
(case word-size
((4) elf32-header-len)
((8) elf64-header-len)
(else (error "invalid word size" word-size))))
(define (elf-header-shoff-offset word-size)
(case word-size
((4) 32)
((8) 40)
(else (error "bad word size" word-size))))
(define ELFCLASS32 1) ; 32-bit objects
(define ELFCLASS64 2) ; 64-bit objects
(define ELFDATA2LSB 1) ; 2's complement, little endian
(define ELFDATA2MSB 2) ; 2's complement, big endian
(define EV_CURRENT 1) ; Current version
(define ELFOSABI_NONE 0) ; UNIX System V ABI */
(define ELFOSABI_HPUX 1) ; HP-UX
(define ELFOSABI_NETBSD 2) ; NetBSD.
(define ELFOSABI_GNU 3) ; Object uses GNU ELF extensions.
(define ELFOSABI_SOLARIS 6) ; Sun Solaris.
(define ELFOSABI_AIX 7) ; IBM AIX.
(define ELFOSABI_IRIX 8) ; SGI Irix.
(define ELFOSABI_FREEBSD 9) ; FreeBSD.
(define ELFOSABI_TRU64 10) ; Compaq TRU64 UNIX.
(define ELFOSABI_MODESTO 11) ; Novell Modesto.
(define ELFOSABI_OPENBSD 12) ; OpenBSD.
(define ELFOSABI_ARM_AEABI 64) ; ARM EABI
(define ELFOSABI_ARM 97) ; ARM
(define ELFOSABI_STANDALONE 255) ; Standalone (embedded) application
(define ET_NONE 0) ; No file type
(define ET_REL 1) ; Relocatable file
(define ET_EXEC 2) ; Executable file
(define ET_DYN 3) ; Shared object file
(define ET_CORE 4) ; Core file
;;
;; Machine types
;;
;; Just a sampling of these values. We could include more, but the
;; important thing is to recognize architectures for which we have a
;; native compiler. Recognizing more common machine types is icing on
;; the cake.
;;
(define EM_NONE 0) ; No machine
(define EM_SPARC 2) ; SUN SPARC
(define EM_386 3) ; Intel 80386
(define EM_MIPS 8) ; MIPS R3000 big-endian
(define EM_PPC 20) ; PowerPC
(define EM_PPC64 21) ; PowerPC 64-bit
(define EM_ARM 40) ; ARM
(define EM_SH 42) ; Hitachi SH
(define EM_SPARCV9 43) ; SPARC v9 64-bit
(define EM_IA_64 50) ; Intel Merced
(define EM_X86_64 62) ; AMD x86-64 architecture
(define cpu-mapping (make-hash-table))
(for-each (lambda (pair)
(hashq-set! cpu-mapping (car pair) (cdr pair)))
`((none . ,EM_NONE)
(sparc . ,EM_SPARC) ; FIXME: map 64-bit to SPARCV9 ?
(i386 . ,EM_386)
(mips . ,EM_MIPS)
(ppc . ,EM_PPC)
(ppc64 . ,EM_PPC64)
(arm . ,EM_ARM) ; FIXME: there are more arm cpu variants
(sh . ,EM_SH) ; FIXME: there are more sh cpu variants
(ia64 . ,EM_IA_64)
(x86_64 . ,EM_X86_64)))
(define SHN_UNDEF 0)
(define host-machine-type
(hashq-ref cpu-mapping
(string->symbol (car (string-split %host-type #\-)))
EM_NONE))
(define host-word-size
(sizeof '*))
(define host-byte-order
(native-endianness))
(define (has-elf-header? bv)
(and
;; e_ident
(>= (bytevector-length bv) 16)
(= (bytevector-u8-ref bv 0) #x7f)
(= (bytevector-u8-ref bv 1) (char->integer #\E))
(= (bytevector-u8-ref bv 2) (char->integer #\L))
(= (bytevector-u8-ref bv 3) (char->integer #\F))
(cond
((= (bytevector-u8-ref bv 4) ELFCLASS32)
(>= (bytevector-length bv) elf32-header-len))
((= (bytevector-u8-ref bv 4) ELFCLASS64)
(>= (bytevector-length bv) elf64-header-len))
(else #f))
(or (= (bytevector-u8-ref bv 5) ELFDATA2LSB)
(= (bytevector-u8-ref bv 5) ELFDATA2MSB))
(= (bytevector-u8-ref bv 6) EV_CURRENT)
;; Look at ABI later.
(= (bytevector-u8-ref bv 8) 0) ; ABI version
;; The rest of the e_ident is padding.
;; e_version
(let ((byte-order (if (= (bytevector-u8-ref bv 5) ELFDATA2LSB)
(endianness little)
(endianness big))))
(= (bytevector-u32-ref bv 20 byte-order) EV_CURRENT))))
(define-record-type <elf>
(make-elf bytes word-size byte-order abi type machine-type
entry phoff shoff flags ehsize
phentsize phnum shentsize shnum shstrndx)
elf?
(bytes elf-bytes)
(word-size elf-word-size)
(byte-order elf-byte-order)
(abi elf-abi)
(type elf-type)
(machine-type elf-machine-type)
(entry elf-entry)
(phoff elf-phoff)
(shoff elf-shoff)
(flags elf-flags)
(ehsize elf-ehsize)
(phentsize elf-phentsize)
(phnum elf-phnum)
(shentsize elf-shentsize)
(shnum elf-shnum)
(shstrndx elf-shstrndx))
(define* (make-elf* #:key (bytes #f)
(byte-order (target-endianness))
(word-size (target-word-size))
(abi ELFOSABI_STANDALONE)
(type ET_DYN)
(machine-type EM_NONE)
(entry 0)
(phoff (elf-header-len word-size))
(shoff -1)
(flags 0)
(ehsize (elf-header-len word-size))
(phentsize (elf-program-header-len word-size))
(phnum 0)
(shentsize (elf-section-header-len word-size))
(shnum 0)
(shstrndx SHN_UNDEF))
(make-elf bytes word-size byte-order abi type machine-type
entry phoff shoff flags ehsize
phentsize phnum shentsize shnum shstrndx))
(define (parse-elf32 bv byte-order)
(make-elf bv 4 byte-order
(bytevector-u8-ref bv 7)
(bytevector-u16-ref bv 16 byte-order)
(bytevector-u16-ref bv 18 byte-order)
(bytevector-u32-ref bv 24 byte-order)
(bytevector-u32-ref bv 28 byte-order)
(bytevector-u32-ref bv 32 byte-order)
(bytevector-u32-ref bv 36 byte-order)
(bytevector-u16-ref bv 40 byte-order)
(bytevector-u16-ref bv 42 byte-order)
(bytevector-u16-ref bv 44 byte-order)
(bytevector-u16-ref bv 46 byte-order)
(bytevector-u16-ref bv 48 byte-order)
(bytevector-u16-ref bv 50 byte-order)))
(define (write-elf-ident bv class data abi)
(bytevector-u8-set! bv 0 #x7f)
(bytevector-u8-set! bv 1 (char->integer #\E))
(bytevector-u8-set! bv 2 (char->integer #\L))
(bytevector-u8-set! bv 3 (char->integer #\F))
(bytevector-u8-set! bv 4 class)
(bytevector-u8-set! bv 5 data)
(bytevector-u8-set! bv 6 EV_CURRENT)
(bytevector-u8-set! bv 7 abi)
(bytevector-u8-set! bv 8 0) ; ABI version
(bytevector-u8-set! bv 9 0) ; Pad to 16 bytes.
(bytevector-u8-set! bv 10 0)
(bytevector-u8-set! bv 11 0)
(bytevector-u8-set! bv 12 0)
(bytevector-u8-set! bv 13 0)
(bytevector-u8-set! bv 14 0)
(bytevector-u8-set! bv 15 0))
(define (write-elf32-header bv elf)
(let ((byte-order (elf-byte-order elf)))
(write-elf-ident bv ELFCLASS32
(case byte-order
((little) ELFDATA2LSB)
((big) ELFDATA2MSB)
(else (error "unknown endianness" byte-order)))
(elf-abi elf))
(bytevector-u16-set! bv 16 (elf-type elf) byte-order)
(bytevector-u16-set! bv 18 (elf-machine-type elf) byte-order)
(bytevector-u32-set! bv 20 EV_CURRENT byte-order)
(bytevector-u32-set! bv 24 (elf-entry elf) byte-order)
(bytevector-u32-set! bv 28 (elf-phoff elf) byte-order)
(bytevector-u32-set! bv 32 (elf-shoff elf) byte-order)
(bytevector-u32-set! bv 36 (elf-flags elf) byte-order)
(bytevector-u16-set! bv 40 (elf-ehsize elf) byte-order)
(bytevector-u16-set! bv 42 (elf-phentsize elf) byte-order)
(bytevector-u16-set! bv 44 (elf-phnum elf) byte-order)
(bytevector-u16-set! bv 46 (elf-shentsize elf) byte-order)
(bytevector-u16-set! bv 48 (elf-shnum elf) byte-order)
(bytevector-u16-set! bv 50 (elf-shstrndx elf) byte-order)))
(define (parse-elf64 bv byte-order)
(make-elf bv 8 byte-order
(bytevector-u8-ref bv 7)
(bytevector-u16-ref bv 16 byte-order)
(bytevector-u16-ref bv 18 byte-order)
(bytevector-u64-ref bv 24 byte-order)
(bytevector-u64-ref bv 32 byte-order)
(bytevector-u64-ref bv 40 byte-order)
(bytevector-u32-ref bv 48 byte-order)
(bytevector-u16-ref bv 52 byte-order)
(bytevector-u16-ref bv 54 byte-order)
(bytevector-u16-ref bv 56 byte-order)
(bytevector-u16-ref bv 58 byte-order)
(bytevector-u16-ref bv 60 byte-order)
(bytevector-u16-ref bv 62 byte-order)))
(define (write-elf64-header bv elf)
(let ((byte-order (elf-byte-order elf)))
(write-elf-ident bv ELFCLASS64
(case byte-order
((little) ELFDATA2LSB)
((big) ELFDATA2MSB)
(else (error "unknown endianness" byte-order)))
(elf-abi elf))
(bytevector-u16-set! bv 16 (elf-type elf) byte-order)
(bytevector-u16-set! bv 18 (elf-machine-type elf) byte-order)
(bytevector-u32-set! bv 20 EV_CURRENT byte-order)
(bytevector-u64-set! bv 24 (elf-entry elf) byte-order)
(bytevector-u64-set! bv 32 (elf-phoff elf) byte-order)
(bytevector-u64-set! bv 40 (elf-shoff elf) byte-order)
(bytevector-u32-set! bv 48 (elf-flags elf) byte-order)
(bytevector-u16-set! bv 52 (elf-ehsize elf) byte-order)
(bytevector-u16-set! bv 54 (elf-phentsize elf) byte-order)
(bytevector-u16-set! bv 56 (elf-phnum elf) byte-order)
(bytevector-u16-set! bv 58 (elf-shentsize elf) byte-order)
(bytevector-u16-set! bv 60 (elf-shnum elf) byte-order)
(bytevector-u16-set! bv 62 (elf-shstrndx elf) byte-order)))
(define (parse-elf bv)
(cond
((has-elf-header? bv)
(let ((class (bytevector-u8-ref bv 4))
(byte-order (let ((data (bytevector-u8-ref bv 5)))
(cond
((= data ELFDATA2LSB) (endianness little))
((= data ELFDATA2MSB) (endianness big))
(else (error "unhandled byte order" data))))))
(cond
((= class ELFCLASS32) (parse-elf32 bv byte-order))
((= class ELFCLASS64) (parse-elf64 bv byte-order))
(else (error "unhandled class" class)))))
(else
(error "Invalid ELF" bv))))
(define* (write-elf-header bv elf)
((case (elf-word-size elf)
((4) write-elf32-header)
((8) write-elf64-header)
(else (error "unknown word size" (elf-word-size elf))))
bv elf))
;;
;; Segment types
;;
(define PT_NULL 0) ; Program header table entry unused
(define PT_LOAD 1) ; Loadable program segment
(define PT_DYNAMIC 2) ; Dynamic linking information
(define PT_INTERP 3) ; Program interpreter
(define PT_NOTE 4) ; Auxiliary information
(define PT_SHLIB 5) ; Reserved
(define PT_PHDR 6) ; Entry for header table itself
(define PT_TLS 7) ; Thread-local storage segment
(define PT_NUM 8) ; Number of defined types
(define PT_LOOS #x60000000) ; Start of OS-specific
(define PT_GNU_EH_FRAME #x6474e550) ; GCC .eh_frame_hdr segment
(define PT_GNU_STACK #x6474e551) ; Indicates stack executability
(define PT_GNU_RELRO #x6474e552) ; Read-only after relocation
;;
;; Segment flags
;;
(define PF_X (ash 1 0)) ; Segment is executable
(define PF_W (ash 1 1)) ; Segment is writable
(define PF_R (ash 1 2)) ; Segment is readable
(define-record-type <elf-segment>
(make-elf-segment index type offset vaddr paddr filesz memsz flags align)
elf-segment?
(index elf-segment-index)
(type elf-segment-type)
(offset elf-segment-offset)
(vaddr elf-segment-vaddr)
(paddr elf-segment-paddr)
(filesz elf-segment-filesz)
(memsz elf-segment-memsz)
(flags elf-segment-flags)
(align elf-segment-align))
(define* (make-elf-segment* #:key (index -1) (type PT_LOAD) (offset 0) (vaddr 0)
(paddr 0) (filesz 0) (memsz filesz)
(flags (logior PF_W PF_R))
(align 8))
(make-elf-segment index type offset vaddr paddr filesz memsz flags align))
;; typedef struct {
;; uint32_t p_type;
;; Elf32_Off p_offset;
;; Elf32_Addr p_vaddr;
;; Elf32_Addr p_paddr;
;; uint32_t p_filesz;
;; uint32_t p_memsz;
;; uint32_t p_flags;
;; uint32_t p_align;
;; } Elf32_Phdr;
(define (parse-elf32-program-header index bv offset byte-order)
(if (<= (+ offset 32) (bytevector-length bv))
(make-elf-segment index
(bytevector-u32-ref bv offset byte-order)
(bytevector-u32-ref bv (+ offset 4) byte-order)
(bytevector-u32-ref bv (+ offset 8) byte-order)
(bytevector-u32-ref bv (+ offset 12) byte-order)
(bytevector-u32-ref bv (+ offset 16) byte-order)
(bytevector-u32-ref bv (+ offset 20) byte-order)
(bytevector-u32-ref bv (+ offset 24) byte-order)
(bytevector-u32-ref bv (+ offset 28) byte-order))
(error "corrupt ELF (offset out of range)" offset)))
(define (write-elf32-program-header bv offset byte-order seg)
(bytevector-u32-set! bv offset (elf-segment-type seg) byte-order)
(bytevector-u32-set! bv (+ offset 4) (elf-segment-offset seg) byte-order)
(bytevector-u32-set! bv (+ offset 8) (elf-segment-vaddr seg) byte-order)
(bytevector-u32-set! bv (+ offset 12) (elf-segment-paddr seg) byte-order)
(bytevector-u32-set! bv (+ offset 16) (elf-segment-filesz seg) byte-order)
(bytevector-u32-set! bv (+ offset 20) (elf-segment-memsz seg) byte-order)
(bytevector-u32-set! bv (+ offset 24) (elf-segment-flags seg) byte-order)
(bytevector-u32-set! bv (+ offset 28) (elf-segment-align seg) byte-order))
;; typedef struct {
;; uint32_t p_type;
;; uint32_t p_flags;
;; Elf64_Off p_offset;
;; Elf64_Addr p_vaddr;
;; Elf64_Addr p_paddr;
;; uint64_t p_filesz;
;; uint64_t p_memsz;
;; uint64_t p_align;
;; } Elf64_Phdr;
;; NB: position of `flags' is different!
(define (parse-elf64-program-header index bv offset byte-order)
(if (<= (+ offset 56) (bytevector-length bv))
(make-elf-segment index
(bytevector-u32-ref bv offset byte-order)
(bytevector-u64-ref bv (+ offset 8) byte-order)
(bytevector-u64-ref bv (+ offset 16) byte-order)
(bytevector-u64-ref bv (+ offset 24) byte-order)
(bytevector-u64-ref bv (+ offset 32) byte-order)
(bytevector-u64-ref bv (+ offset 40) byte-order)
(bytevector-u32-ref bv (+ offset 4) byte-order)
(bytevector-u64-ref bv (+ offset 48) byte-order))
(error "corrupt ELF (offset out of range)" offset)))
(define (write-elf64-program-header bv offset byte-order seg)
(bytevector-u32-set! bv offset (elf-segment-type seg) byte-order)
(bytevector-u64-set! bv (+ offset 8) (elf-segment-offset seg) byte-order)
(bytevector-u64-set! bv (+ offset 16) (elf-segment-vaddr seg) byte-order)
(bytevector-u64-set! bv (+ offset 24) (elf-segment-paddr seg) byte-order)
(bytevector-u64-set! bv (+ offset 32) (elf-segment-filesz seg) byte-order)
(bytevector-u64-set! bv (+ offset 40) (elf-segment-memsz seg) byte-order)
(bytevector-u32-set! bv (+ offset 4) (elf-segment-flags seg) byte-order)
(bytevector-u64-set! bv (+ offset 48) (elf-segment-align seg) byte-order))
(define (write-elf-program-header bv offset byte-order word-size seg)
((case word-size
((4) write-elf32-program-header)
((8) write-elf64-program-header)
(else (error "invalid word size" word-size)))
bv offset byte-order seg))
(define (elf-program-header-len word-size)
(case word-size
((4) 32)
((8) 56)
(else (error "bad word size" word-size))))
(define (elf-segment elf n)
(if (not (< -1 n (elf-phnum elf)))
(error "bad segment number" n))
((case (elf-word-size elf)
((4) parse-elf32-program-header)
((8) parse-elf64-program-header)
(else (error "unhandled pointer size")))
n
(elf-bytes elf)
(+ (elf-phoff elf) (* n (elf-phentsize elf)))
(elf-byte-order elf)))
(define (elf-segments elf)
(let lp ((n (elf-phnum elf)) (out '()))
(if (zero? n)
out
(lp (1- n) (cons (elf-segment elf (1- n)) out)))))
(define-record-type <elf-section>
(make-elf-section index name type flags
addr offset size link info addralign entsize)
elf-section?
(index elf-section-index)
(name elf-section-name)
(type elf-section-type)
(flags elf-section-flags)
(addr elf-section-addr)
(offset elf-section-offset)
(size elf-section-size)
(link elf-section-link)
(info elf-section-info)
(addralign elf-section-addralign)
(entsize elf-section-entsize))
(define* (make-elf-section* #:key (index SHN_UNDEF) (name 0) (type SHT_PROGBITS)
(flags SHF_ALLOC) (addr 0) (offset 0) (size 0)
(link 0) (info 0) (addralign 8) (entsize 0))
(make-elf-section index name type flags addr offset size link info addralign
entsize))
;; typedef struct {
;; uint32_t sh_name;
;; uint32_t sh_type;
;; uint32_t sh_flags;
;; Elf32_Addr sh_addr;
;; Elf32_Off sh_offset;
;; uint32_t sh_size;
;; uint32_t sh_link;
;; uint32_t sh_info;
;; uint32_t sh_addralign;
;; uint32_t sh_entsize;
;; } Elf32_Shdr;
(define (parse-elf32-section-header index bv offset byte-order)
(if (<= (+ offset 40) (bytevector-length bv))
(make-elf-section index
(bytevector-u32-ref bv offset byte-order)
(bytevector-u32-ref bv (+ offset 4) byte-order)
(bytevector-u32-ref bv (+ offset 8) byte-order)
(bytevector-u32-ref bv (+ offset 12) byte-order)
(bytevector-u32-ref bv (+ offset 16) byte-order)
(bytevector-u32-ref bv (+ offset 20) byte-order)
(bytevector-u32-ref bv (+ offset 24) byte-order)
(bytevector-u32-ref bv (+ offset 28) byte-order)
(bytevector-u32-ref bv (+ offset 32) byte-order)
(bytevector-u32-ref bv (+ offset 36) byte-order))
(error "corrupt ELF (offset out of range)" offset)))
(define (write-elf32-section-header bv offset byte-order sec)
(bytevector-u32-set! bv offset (elf-section-name sec) byte-order)
(bytevector-u32-set! bv (+ offset 4) (elf-section-type sec) byte-order)
(bytevector-u32-set! bv (+ offset 8) (elf-section-flags sec) byte-order)
(bytevector-u32-set! bv (+ offset 12) (elf-section-addr sec) byte-order)
(bytevector-u32-set! bv (+ offset 16) (elf-section-offset sec) byte-order)
(bytevector-u32-set! bv (+ offset 20) (elf-section-size sec) byte-order)
(bytevector-u32-set! bv (+ offset 24) (elf-section-link sec) byte-order)
(bytevector-u32-set! bv (+ offset 28) (elf-section-info sec) byte-order)
(bytevector-u32-set! bv (+ offset 32) (elf-section-addralign sec) byte-order)
(bytevector-u32-set! bv (+ offset 36) (elf-section-entsize sec) byte-order))
;; typedef struct {
;; uint32_t sh_name;
;; uint32_t sh_type;
;; uint64_t sh_flags;
;; Elf64_Addr sh_addr;
;; Elf64_Off sh_offset;
;; uint64_t sh_size;
;; uint32_t sh_link;
;; uint32_t sh_info;
;; uint64_t sh_addralign;
;; uint64_t sh_entsize;
;; } Elf64_Shdr;
(define (elf-section-header-len word-size)
(case word-size
((4) 40)
((8) 64)
(else (error "bad word size" word-size))))
(define (elf-section-header-addr-offset word-size)
(case word-size
((4) 12)
((8) 16)
(else (error "bad word size" word-size))))
(define (elf-section-header-offset-offset word-size)
(case word-size
((4) 16)
((8) 24)
(else (error "bad word size" word-size))))
(define (parse-elf64-section-header index bv offset byte-order)
(if (<= (+ offset 64) (bytevector-length bv))
(make-elf-section index
(bytevector-u32-ref bv offset byte-order)
(bytevector-u32-ref bv (+ offset 4) byte-order)
(bytevector-u64-ref bv (+ offset 8) byte-order)
(bytevector-u64-ref bv (+ offset 16) byte-order)
(bytevector-u64-ref bv (+ offset 24) byte-order)
(bytevector-u64-ref bv (+ offset 32) byte-order)
(bytevector-u32-ref bv (+ offset 40) byte-order)
(bytevector-u32-ref bv (+ offset 44) byte-order)
(bytevector-u64-ref bv (+ offset 48) byte-order)
(bytevector-u64-ref bv (+ offset 56) byte-order))
(error "corrupt ELF (offset out of range)" offset)))
(define (write-elf64-section-header bv offset byte-order sec)
(bytevector-u32-set! bv offset (elf-section-name sec) byte-order)
(bytevector-u32-set! bv (+ offset 4) (elf-section-type sec) byte-order)
(bytevector-u64-set! bv (+ offset 8) (elf-section-flags sec) byte-order)
(bytevector-u64-set! bv (+ offset 16) (elf-section-addr sec) byte-order)
(bytevector-u64-set! bv (+ offset 24) (elf-section-offset sec) byte-order)
(bytevector-u64-set! bv (+ offset 32) (elf-section-size sec) byte-order)
(bytevector-u32-set! bv (+ offset 40) (elf-section-link sec) byte-order)
(bytevector-u32-set! bv (+ offset 44) (elf-section-info sec) byte-order)
(bytevector-u64-set! bv (+ offset 48) (elf-section-addralign sec) byte-order)
(bytevector-u64-set! bv (+ offset 56) (elf-section-entsize sec) byte-order))
(define (elf-section elf n)
(if (not (< -1 n (elf-shnum elf)))
(error "bad section number" n))
((case (elf-word-size elf)
((4) parse-elf32-section-header)
((8) parse-elf64-section-header)
(else (error "unhandled pointer size")))
n
(elf-bytes elf)
(+ (elf-shoff elf) (* n (elf-shentsize elf)))
(elf-byte-order elf)))
(define (write-elf-section-header bv offset byte-order word-size sec)
((case word-size
((4) write-elf32-section-header)
((8) write-elf64-section-header)
(else (error "invalid word size" word-size)))
bv offset byte-order sec))
(define (elf-sections elf)
(let lp ((n (elf-shnum elf)) (out '()))
(if (zero? n)
out
(lp (1- n) (cons (elf-section elf (1- n)) out)))))
;;
;; Section Types
;;
(define SHT_NULL 0) ; Section header table entry unused
(define SHT_PROGBITS 1) ; Program data
(define SHT_SYMTAB 2) ; Symbol table
(define SHT_STRTAB 3) ; String table
(define SHT_RELA 4) ; Relocation entries with addends
(define SHT_HASH 5) ; Symbol hash table
(define SHT_DYNAMIC 6) ; Dynamic linking information
(define SHT_NOTE 7) ; Notes
(define SHT_NOBITS 8) ; Program space with no data (bss)
(define SHT_REL 9) ; Relocation entries, no addends
(define SHT_SHLIB 10) ; Reserved
(define SHT_DYNSYM 11) ; Dynamic linker symbol table
(define SHT_INIT_ARRAY 14) ; Array of constructors
(define SHT_FINI_ARRAY 15) ; Array of destructors
(define SHT_PREINIT_ARRAY 16) ; Array of pre-constructors
(define SHT_GROUP 17) ; Section group
(define SHT_SYMTAB_SHNDX 18) ; Extended section indeces
(define SHT_NUM 19) ; Number of defined types.
(define SHT_LOOS #x60000000) ; Start OS-specific.
(define SHT_HIOS #x6fffffff) ; End OS-specific type
(define SHT_LOPROC #x70000000) ; Start of processor-specific
(define SHT_HIPROC #x7fffffff) ; End of processor-specific
(define SHT_LOUSER #x80000000) ; Start of application-specific
(define SHT_HIUSER #x8fffffff) ; End of application-specific
;;
;; Section Flags
;;
(define SHF_WRITE (ash 1 0)) ; Writable
(define SHF_ALLOC (ash 1 1)) ; Occupies memory during execution
(define SHF_EXECINSTR (ash 1 2)) ; Executable
(define SHF_MERGE (ash 1 4)) ; Might be merged
(define SHF_STRINGS (ash 1 5)) ; Contains nul-terminated strings
(define SHF_INFO_LINK (ash 1 6)) ; `sh_info' contains SHT index
(define SHF_LINK_ORDER (ash 1 7)) ; Preserve order after combining
(define SHF_OS_NONCONFORMING (ash 1 8)) ; Non-standard OS specific handling required
(define SHF_GROUP (ash 1 9)) ; Section is member of a group.
(define SHF_TLS (ash 1 10)) ; Section hold thread-local data.
;;
;; Dynamic entry types. The DT_GUILE types are non-standard.
;;
(define DT_NULL 0) ; Marks end of dynamic section
(define DT_NEEDED 1) ; Name of needed library
(define DT_PLTRELSZ 2) ; Size in bytes of PLT relocs
(define DT_PLTGOT 3) ; Processor defined value
(define DT_HASH 4) ; Address of symbol hash table
(define DT_STRTAB 5) ; Address of string table
(define DT_SYMTAB 6) ; Address of symbol table
(define DT_RELA 7) ; Address of Rela relocs
(define DT_RELASZ 8) ; Total size of Rela relocs
(define DT_RELAENT 9) ; Size of one Rela reloc
(define DT_STRSZ 10) ; Size of string table
(define DT_SYMENT 11) ; Size of one symbol table entry
(define DT_INIT 12) ; Address of init function
(define DT_FINI 13) ; Address of termination function
(define DT_SONAME 14) ; Name of shared object
(define DT_RPATH 15) ; Library search path (deprecated)
(define DT_SYMBOLIC 16) ; Start symbol search here
(define DT_REL 17) ; Address of Rel relocs
(define DT_RELSZ 18) ; Total size of Rel relocs
(define DT_RELENT 19) ; Size of one Rel reloc
(define DT_PLTREL 20) ; Type of reloc in PLT
(define DT_DEBUG 21) ; For debugging ; unspecified
(define DT_TEXTREL 22) ; Reloc might modify .text
(define DT_JMPREL 23) ; Address of PLT relocs
(define DT_BIND_NOW 24) ; Process relocations of object
(define DT_INIT_ARRAY 25) ; Array with addresses of init fct
(define DT_FINI_ARRAY 26) ; Array with addresses of fini fct
(define DT_INIT_ARRAYSZ 27) ; Size in bytes of DT_INIT_ARRAY
(define DT_FINI_ARRAYSZ 28) ; Size in bytes of DT_FINI_ARRAY
(define DT_RUNPATH 29) ; Library search path
(define DT_FLAGS 30) ; Flags for the object being loaded
(define DT_ENCODING 32) ; Start of encoded range
(define DT_PREINIT_ARRAY 32) ; Array with addresses of preinit fc
(define DT_PREINIT_ARRAYSZ 33) ; size in bytes of DT_PREINIT_ARRAY
(define DT_NUM 34) ; Number used
(define DT_LOGUILE #x37146000) ; Start of Guile-specific
(define DT_GUILE_GC_ROOT #x37146000) ; Offset of GC roots
(define DT_GUILE_GC_ROOT_SZ #x37146001) ; Size in machine words of GC roots
(define DT_GUILE_ENTRY #x37146002) ; Address of entry thunk
(define DT_GUILE_VM_VERSION #x37146003) ; Bytecode version
(define DT_GUILE_FRAME_MAPS #x37146004) ; Offset of .guile.frame-maps
(define DT_HIGUILE #x37146fff) ; End of Guile-specific
(define DT_LOOS #x6000000d) ; Start of OS-specific
(define DT_HIOS #x6ffff000) ; End of OS-specific
(define DT_LOPROC #x70000000) ; Start of processor-specific
(define DT_HIPROC #x7fffffff) ; End of processor-specific
(define (string-table-ref bv offset)
(let lp ((end offset))
(if (zero? (bytevector-u8-ref bv end))
(let ((out (make-bytevector (- end offset))))
(bytevector-copy! bv offset out 0 (- end offset))
(utf8->string out))
(lp (1+ end)))))
(define (elf-section-by-name elf name)
(let ((off (elf-section-offset (elf-section elf (elf-shstrndx elf)))))
(let lp ((n (elf-shnum elf)))
(and (> n 0)
(let ((section (elf-section elf (1- n))))
(if (equal? (string-table-ref (elf-bytes elf)
(+ off (elf-section-name section)))
name)
section
(lp (1- n))))))))
(define (elf-sections-by-name elf)
(let* ((sections (elf-sections elf))
(off (elf-section-offset (list-ref sections (elf-shstrndx elf)))))
(map (lambda (section)
(cons (string-table-ref (elf-bytes elf)
(+ off (elf-section-name section)))
section))
sections)))
(define-record-type <elf-symbol>
(make-elf-symbol name value size info other shndx)
elf-symbol?
(name elf-symbol-name)
(value elf-symbol-value)
(size elf-symbol-size)
(info elf-symbol-info)
(other elf-symbol-other)
(shndx elf-symbol-shndx))
(define* (make-elf-symbol* #:key (name 0) (value 0) (size 0)
(binding STB_LOCAL) (type STT_NOTYPE)
(info (logior (ash binding 4) type))
(visibility STV_DEFAULT) (other visibility)
(shndx SHN_UNDEF))
(make-elf-symbol name value size info other shndx))
;; typedef struct {
;; uint32_t st_name;
;; Elf32_Addr st_value;
;; uint32_t st_size;
;; unsigned char st_info;
;; unsigned char st_other;
;; uint16_t st_shndx;
;; } Elf32_Sym;
(define (elf-symbol-len word-size)
(case word-size
((4) 16)
((8) 24)
(else (error "bad word size" word-size))))
(define (elf-symbol-value-offset word-size)
(case word-size
((4) 4)
((8) 8)
(else (error "bad word size" word-size))))
(define (parse-elf32-symbol bv offset stroff byte-order)
(if (<= (+ offset 16) (bytevector-length bv))
(make-elf-symbol (let ((name (bytevector-u32-ref bv offset byte-order)))
(if stroff
(string-table-ref bv (+ stroff name))
name))
(bytevector-u32-ref bv (+ offset 4) byte-order)
(bytevector-u32-ref bv (+ offset 8) byte-order)
(bytevector-u8-ref bv (+ offset 12))
(bytevector-u8-ref bv (+ offset 13))
(bytevector-u16-ref bv (+ offset 14) byte-order))
(error "corrupt ELF (offset out of range)" offset)))
(define (write-elf32-symbol bv offset byte-order sym)
(bytevector-u32-set! bv offset (elf-symbol-name sym) byte-order)
(bytevector-u32-set! bv (+ offset 4) (elf-symbol-value sym) byte-order)
(bytevector-u32-set! bv (+ offset 8) (elf-symbol-size sym) byte-order)
(bytevector-u8-set! bv (+ offset 12) (elf-symbol-info sym))
(bytevector-u8-set! bv (+ offset 13) (elf-symbol-other sym))
(bytevector-u16-set! bv (+ offset 14) (elf-symbol-shndx sym) byte-order))
;; typedef struct {
;; uint32_t st_name;
;; unsigned char st_info;
;; unsigned char st_other;
;; uint16_t st_shndx;
;; Elf64_Addr st_value;
;; uint64_t st_size;
;; } Elf64_Sym;
(define (parse-elf64-symbol bv offset stroff byte-order)
(if (<= (+ offset 24) (bytevector-length bv))
(make-elf-symbol (let ((name (bytevector-u32-ref bv offset byte-order)))
(if stroff
(string-table-ref bv (+ stroff name))
name))
(bytevector-u64-ref bv (+ offset 8) byte-order)
(bytevector-u64-ref bv (+ offset 16) byte-order)
(bytevector-u8-ref bv (+ offset 4))
(bytevector-u8-ref bv (+ offset 5))
(bytevector-u16-ref bv (+ offset 6) byte-order))
(error "corrupt ELF (offset out of range)" offset)))
(define (write-elf64-symbol bv offset byte-order sym)
(bytevector-u32-set! bv offset (elf-symbol-name sym) byte-order)
(bytevector-u8-set! bv (+ offset 4) (elf-symbol-info sym))
(bytevector-u8-set! bv (+ offset 5) (elf-symbol-other sym))
(bytevector-u16-set! bv (+ offset 6) (elf-symbol-shndx sym) byte-order)
(bytevector-u64-set! bv (+ offset 8) (elf-symbol-value sym) byte-order)
(bytevector-u64-set! bv (+ offset 16) (elf-symbol-size sym) byte-order))
(define (write-elf-symbol bv offset byte-order word-size sym)
((case word-size
((4) write-elf32-symbol)
((8) write-elf64-symbol)
(else (error "invalid word size" word-size)))
bv offset byte-order sym))
(define (elf-symbol-table-len section)
(let ((len (elf-section-size section))
(entsize (elf-section-entsize section)))
(unless (and (not (zero? entsize)) (zero? (modulo len entsize)))
(error "bad symbol table" section))
(/ len entsize)))
(define* (elf-symbol-table-ref elf section n #:optional strtab)
(let ((bv (elf-bytes elf))
(byte-order (elf-byte-order elf))
(stroff (and strtab (elf-section-offset strtab)))
(base (elf-section-offset section))
(len (elf-section-size section))
(entsize (elf-section-entsize section)))
(unless (<= (* (1+ n) entsize) len)
(error "out of range symbol table access" section n))
(case (elf-word-size elf)
((4)
(unless (<= 16 entsize)
(error "bad entsize for symbol table" section))
(parse-elf32-symbol bv (+ base (* n entsize)) stroff byte-order))
((8)
(unless (<= 24 entsize)
(error "bad entsize for symbol table" section))
(parse-elf64-symbol bv (+ base (* n entsize)) stroff byte-order))
(else (error "bad word size" elf)))))
;; Legal values for ST_BIND subfield of st_info (symbol binding).
(define STB_LOCAL 0) ; Local symbol
(define STB_GLOBAL 1) ; Global symbol
(define STB_WEAK 2) ; Weak symbol
(define STB_NUM 3) ; Number of defined types.
(define STB_LOOS 10) ; Start of OS-specific
(define STB_GNU_UNIQUE 10) ; Unique symbol.
(define STB_HIOS 12) ; End of OS-specific
(define STB_LOPROC 13) ; Start of processor-specific
(define STB_HIPROC 15) ; End of processor-specific
;; Legal values for ST_TYPE subfield of st_info (symbol type).
(define STT_NOTYPE 0) ; Symbol type is unspecified
(define STT_OBJECT 1) ; Symbol is a data object
(define STT_FUNC 2) ; Symbol is a code object
(define STT_SECTION 3) ; Symbol associated with a section
(define STT_FILE 4) ; Symbol's name is file name
(define STT_COMMON 5) ; Symbol is a common data object
(define STT_TLS 6) ; Symbol is thread-local data objec
(define STT_NUM 7) ; Number of defined types.
(define STT_LOOS 10) ; Start of OS-specific
(define STT_GNU_IFUNC 10) ; Symbol is indirect code object
(define STT_HIOS 12) ; End of OS-specific
(define STT_LOPROC 13) ; Start of processor-specific
(define STT_HIPROC 15) ; End of processor-specific
;; Symbol visibility specification encoded in the st_other field.
(define STV_DEFAULT 0) ; Default symbol visibility rules
(define STV_INTERNAL 1) ; Processor specific hidden class
(define STV_HIDDEN 2) ; Sym unavailable in other modules
(define STV_PROTECTED 3) ; Not preemptible, not exported
(define (elf-symbol-binding sym)
(ash (elf-symbol-info sym) -4))
(define (elf-symbol-type sym)
(logand (elf-symbol-info sym) #xf))
(define (elf-symbol-visibility sym)
(logand (elf-symbol-other sym) #x3))
(define NT_GNU_ABI_TAG 1)
(define NT_GNU_HWCAP 2)
(define NT_GNU_BUILD_ID 3)
(define NT_GNU_GOLD_VERSION 4)
(define-record-type <elf-note>
(make-elf-note name desc type)
elf-note?
(name elf-note-name)
(desc elf-note-desc)
(type elf-note-type))
(define (parse-elf-note elf section)
(let ((bv (elf-bytes elf))
(byte-order (elf-byte-order elf))
(offset (elf-section-offset section)))
(unless (<= (+ offset 12) (bytevector-length bv))
(error "corrupt ELF (offset out of range)" offset))
(let ((namesz (bytevector-u32-ref bv offset byte-order))
(descsz (bytevector-u32-ref bv (+ offset 4) byte-order))
(type (bytevector-u32-ref bv (+ offset 8) byte-order)))
(unless (<= (+ offset 12 namesz descsz) (bytevector-length bv))
(error "corrupt ELF (offset out of range)" offset))
(let ((name (make-bytevector (1- namesz)))
(desc (make-bytevector descsz)))
(bytevector-copy! bv (+ offset 12) name 0 (1- namesz))
(bytevector-copy! bv (+ offset 12 namesz) desc 0 descsz)
(make-elf-note (utf8->string name) desc type)))))