;;; 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)))))