elf.scm 41 KB

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  1. ;;; Guile ELF reader and writer
  2. ;; Copyright (C) 2011, 2012, 2013 Free Software Foundation, Inc.
  3. ;;;; This library is free software; you can redistribute it and/or
  4. ;;;; modify it under the terms of the GNU Lesser General Public
  5. ;;;; License as published by the Free Software Foundation; either
  6. ;;;; version 3 of the License, or (at your option) any later version.
  7. ;;;;
  8. ;;;; This library is distributed in the hope that it will be useful,
  9. ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. ;;;; Lesser General Public License for more details.
  12. ;;;;
  13. ;;;; You should have received a copy of the GNU Lesser General Public
  14. ;;;; License along with this library; if not, write to the Free Software
  15. ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16. ;;; Commentary:
  17. ;;;
  18. ;;; A module to read and write Executable and Linking Format (ELF)
  19. ;;; files.
  20. ;;;
  21. ;;; This module exports a number of record types that represent the
  22. ;;; various parts that make up ELF files. Fundamentally this is the
  23. ;;; main header, the segment headers (program headers), and the section
  24. ;;; headers. It also exports bindings for symbolic constants and
  25. ;;; utilities to parse and write special kinds of ELF sections.
  26. ;;;
  27. ;;; See elf(5) for more information on ELF.
  28. ;;;
  29. ;;; Code:
  30. (define-module (system vm elf)
  31. #:use-module (rnrs bytevectors)
  32. #:use-module (system foreign)
  33. #:use-module (system base target)
  34. #:use-module (srfi srfi-9)
  35. #:use-module (ice-9 receive)
  36. #:use-module (ice-9 vlist)
  37. #:export (has-elf-header?
  38. (make-elf* . make-elf)
  39. elf?
  40. elf-bytes elf-word-size elf-byte-order
  41. elf-abi elf-type elf-machine-type
  42. elf-entry elf-phoff elf-shoff elf-flags elf-ehsize
  43. elf-phentsize elf-phnum elf-shentsize elf-shnum elf-shstrndx
  44. elf-header-len elf-header-shoff-offset
  45. write-elf-header
  46. (make-elf-segment* . make-elf-segment)
  47. elf-segment?
  48. elf-segment-index
  49. elf-segment-type elf-segment-offset elf-segment-vaddr
  50. elf-segment-paddr elf-segment-filesz elf-segment-memsz
  51. elf-segment-flags elf-segment-align
  52. elf-program-header-len write-elf-program-header
  53. PT_NULL PT_LOAD PT_DYNAMIC PT_INTERP PT_NOTE PT_SHLIB
  54. PT_PHDR PT_TLS PT_NUM PT_LOOS PT_GNU_EH_FRAME PT_GNU_STACK
  55. PT_GNU_RELRO
  56. PF_R PF_W PF_X
  57. (make-elf-section* . make-elf-section)
  58. elf-section?
  59. elf-section-index
  60. elf-section-name elf-section-type elf-section-flags
  61. elf-section-addr elf-section-offset elf-section-size
  62. elf-section-link elf-section-info elf-section-addralign
  63. elf-section-entsize
  64. elf-section-header-len elf-section-header-addr-offset
  65. elf-section-header-offset-offset
  66. write-elf-section-header
  67. (make-elf-symbol* . make-elf-symbol)
  68. elf-symbol?
  69. elf-symbol-name elf-symbol-value elf-symbol-size
  70. elf-symbol-info elf-symbol-other elf-symbol-shndx
  71. elf-symbol-binding elf-symbol-type elf-symbol-visibility
  72. elf-symbol-len write-elf-symbol
  73. SHN_UNDEF
  74. SHT_NULL SHT_PROGBITS SHT_SYMTAB SHT_STRTAB SHT_RELA
  75. SHT_HASH SHT_DYNAMIC SHT_NOTE SHT_NOBITS SHT_REL SHT_SHLIB
  76. SHT_DYNSYM SHT_INIT_ARRAY SHT_FINI_ARRAY SHT_PREINIT_ARRAY
  77. SHT_GROUP SHT_SYMTAB_SHNDX SHT_NUM SHT_LOOS SHT_HIOS
  78. SHT_LOPROC SHT_HIPROC SHT_LOUSER SHT_HIUSER
  79. SHF_WRITE SHF_ALLOC SHF_EXECINSTR SHF_MERGE SHF_STRINGS
  80. SHF_INFO_LINK SHF_LINK_ORDER SHF_OS_NONCONFORMING SHF_GROUP
  81. SHF_TLS
  82. DT_NULL DT_NEEDED DT_PLTRELSZ DT_PLTGOT DT_HASH DT_STRTAB
  83. DT_SYMTAB DT_RELA DT_RELASZ DT_RELAENT DT_STRSZ DT_SYMENT
  84. DT_INIT DT_FINI DT_SONAME DT_RPATH DT_SYMBOLIC DT_REL
  85. DT_RELSZ DT_RELENT DT_PLTREL DT_DEBUG DT_TEXTREL DT_JMPREL
  86. DT_BIND_NOW DT_INIT_ARRAY DT_FINI_ARRAY DT_INIT_ARRAYSZ
  87. DT_FINI_ARRAYSZ DT_RUNPATH DT_FLAGS DT_ENCODING
  88. DT_PREINIT_ARRAY DT_PREINIT_ARRAYSZ DT_NUM DT_LOGUILE
  89. DT_GUILE_GC_ROOT DT_GUILE_GC_ROOT_SZ DT_GUILE_ENTRY
  90. DT_GUILE_RTL_VERSION DT_HIGUILE DT_LOOS DT_HIOS DT_LOPROC
  91. DT_HIPROC
  92. string-table-ref
  93. STB_LOCAL STB_GLOBAL STB_WEAK STB_NUM STB_LOOS STB_GNU
  94. STB_HIOS STB_LOPROC STB_HIPROC
  95. STT_NOTYPE STT_OBJECT STT_FUNC STT_SECTION STT_FILE
  96. STT_COMMON STT_TLS STT_NUM STT_LOOS STT_GNU STT_HIOS
  97. STT_LOPROC STT_HIPROC
  98. STV_DEFAULT STV_INTERNAL STV_HIDDEN STV_PROTECTED
  99. NT_GNU_ABI_TAG NT_GNU_HWCAP NT_GNU_BUILD_ID NT_GNU_GOLD_VERSION
  100. parse-elf
  101. elf-segment elf-segments
  102. elf-section elf-sections elf-section-by-name elf-sections-by-name
  103. elf-symbol-table-len elf-symbol-table-ref
  104. parse-elf-note
  105. elf-note-name elf-note-desc elf-note-type))
  106. ;; #define EI_NIDENT 16
  107. ;; typedef struct {
  108. ;; unsigned char e_ident[EI_NIDENT];
  109. ;; uint16_t e_type;
  110. ;; uint16_t e_machine;
  111. ;; uint32_t e_version;
  112. ;; ElfN_Addr e_entry;
  113. ;; ElfN_Off e_phoff;
  114. ;; ElfN_Off e_shoff;
  115. ;; uint32_t e_flags;
  116. ;; uint16_t e_ehsize;
  117. ;; uint16_t e_phentsize;
  118. ;; uint16_t e_phnum;
  119. ;; uint16_t e_shentsize;
  120. ;; uint16_t e_shnum;
  121. ;; uint16_t e_shstrndx;
  122. ;; } ElfN_Ehdr;
  123. (define elf32-header-len 52)
  124. (define elf64-header-len 64)
  125. (define (elf-header-len word-size)
  126. (case word-size
  127. ((4) elf32-header-len)
  128. ((8) elf64-header-len)
  129. (else (error "invalid word size" word-size))))
  130. (define (elf-header-shoff-offset word-size)
  131. (case word-size
  132. ((4) 32)
  133. ((8) 40)
  134. (else (error "bad word size" word-size))))
  135. (define ELFCLASS32 1) ; 32-bit objects
  136. (define ELFCLASS64 2) ; 64-bit objects
  137. (define ELFDATA2LSB 1) ; 2's complement, little endian
  138. (define ELFDATA2MSB 2) ; 2's complement, big endian
  139. (define EV_CURRENT 1) ; Current version
  140. (define ELFOSABI_STANDALONE 255) ; Standalone (embedded) application
  141. (define ET_DYN 3) ; Shared object file
  142. ;;
  143. ;; Machine types
  144. ;;
  145. ;; Just a sampling of these values. We could include more, but the
  146. ;; important thing is to recognize architectures for which we have a
  147. ;; native compiler. Recognizing more common machine types is icing on
  148. ;; the cake.
  149. ;;
  150. (define EM_NONE 0) ; No machine
  151. (define EM_SPARC 2) ; SUN SPARC
  152. (define EM_386 3) ; Intel 80386
  153. (define EM_MIPS 8) ; MIPS R3000 big-endian
  154. (define EM_PPC 20) ; PowerPC
  155. (define EM_PPC64 21) ; PowerPC 64-bit
  156. (define EM_ARM 40) ; ARM
  157. (define EM_SH 42) ; Hitachi SH
  158. (define EM_SPARCV9 43) ; SPARC v9 64-bit
  159. (define EM_IA_64 50) ; Intel Merced
  160. (define EM_X86_64 62) ; AMD x86-64 architecture
  161. (define cpu-mapping (make-hash-table))
  162. (for-each (lambda (pair)
  163. (hashq-set! cpu-mapping (car pair) (cdr pair)))
  164. `((none . ,EM_NONE)
  165. (sparc . ,EM_SPARC) ; FIXME: map 64-bit to SPARCV9 ?
  166. (i386 . ,EM_386)
  167. (mips . ,EM_MIPS)
  168. (ppc . ,EM_PPC)
  169. (ppc64 . ,EM_PPC64)
  170. (arm . ,EM_ARM) ; FIXME: there are more arm cpu variants
  171. (sh . ,EM_SH) ; FIXME: there are more sh cpu variants
  172. (ia64 . ,EM_IA_64)
  173. (x86_64 . ,EM_X86_64)))
  174. (define SHN_UNDEF 0)
  175. (define host-machine-type
  176. (hashq-ref cpu-mapping
  177. (string->symbol (car (string-split %host-type #\-)))
  178. EM_NONE))
  179. (define host-word-size
  180. (sizeof '*))
  181. (define host-byte-order
  182. (native-endianness))
  183. (define (has-elf-header? bv)
  184. (and
  185. ;; e_ident
  186. (>= (bytevector-length bv) 16)
  187. (= (bytevector-u8-ref bv 0) #x7f)
  188. (= (bytevector-u8-ref bv 1) (char->integer #\E))
  189. (= (bytevector-u8-ref bv 2) (char->integer #\L))
  190. (= (bytevector-u8-ref bv 3) (char->integer #\F))
  191. (cond
  192. ((= (bytevector-u8-ref bv 4) ELFCLASS32)
  193. (>= (bytevector-length bv) elf32-header-len))
  194. ((= (bytevector-u8-ref bv 4) ELFCLASS64)
  195. (>= (bytevector-length bv) elf64-header-len))
  196. (else #f))
  197. (or (= (bytevector-u8-ref bv 5) ELFDATA2LSB)
  198. (= (bytevector-u8-ref bv 5) ELFDATA2MSB))
  199. (= (bytevector-u8-ref bv 6) EV_CURRENT)
  200. ;; Look at ABI later.
  201. (= (bytevector-u8-ref bv 8) 0) ; ABI version
  202. ;; The rest of the e_ident is padding.
  203. ;; e_version
  204. (let ((byte-order (if (= (bytevector-u8-ref bv 5) ELFDATA2LSB)
  205. (endianness little)
  206. (endianness big))))
  207. (= (bytevector-u32-ref bv 20 byte-order) EV_CURRENT))))
  208. (define-record-type <elf>
  209. (make-elf bytes word-size byte-order abi type machine-type
  210. entry phoff shoff flags ehsize
  211. phentsize phnum shentsize shnum shstrndx)
  212. elf?
  213. (bytes elf-bytes)
  214. (word-size elf-word-size)
  215. (byte-order elf-byte-order)
  216. (abi elf-abi)
  217. (type elf-type)
  218. (machine-type elf-machine-type)
  219. (entry elf-entry)
  220. (phoff elf-phoff)
  221. (shoff elf-shoff)
  222. (flags elf-flags)
  223. (ehsize elf-ehsize)
  224. (phentsize elf-phentsize)
  225. (phnum elf-phnum)
  226. (shentsize elf-shentsize)
  227. (shnum elf-shnum)
  228. (shstrndx elf-shstrndx))
  229. (define* (make-elf* #:key (bytes #f)
  230. (byte-order (target-endianness))
  231. (word-size (target-word-size))
  232. (abi ELFOSABI_STANDALONE)
  233. (type ET_DYN)
  234. (machine-type EM_NONE)
  235. (entry 0)
  236. (phoff (elf-header-len word-size))
  237. (shoff -1)
  238. (flags 0)
  239. (ehsize (elf-header-len word-size))
  240. (phentsize (elf-program-header-len word-size))
  241. (phnum 0)
  242. (shentsize (elf-section-header-len word-size))
  243. (shnum 0)
  244. (shstrndx SHN_UNDEF))
  245. (make-elf bytes word-size byte-order abi type machine-type
  246. entry phoff shoff flags ehsize
  247. phentsize phnum shentsize shnum shstrndx))
  248. (define (parse-elf32 bv byte-order)
  249. (make-elf bv 4 byte-order
  250. (bytevector-u8-ref bv 7)
  251. (bytevector-u16-ref bv 16 byte-order)
  252. (bytevector-u16-ref bv 18 byte-order)
  253. (bytevector-u32-ref bv 24 byte-order)
  254. (bytevector-u32-ref bv 28 byte-order)
  255. (bytevector-u32-ref bv 32 byte-order)
  256. (bytevector-u32-ref bv 36 byte-order)
  257. (bytevector-u16-ref bv 40 byte-order)
  258. (bytevector-u16-ref bv 42 byte-order)
  259. (bytevector-u16-ref bv 44 byte-order)
  260. (bytevector-u16-ref bv 46 byte-order)
  261. (bytevector-u16-ref bv 48 byte-order)
  262. (bytevector-u16-ref bv 50 byte-order)))
  263. (define (write-elf-ident bv class data abi)
  264. (bytevector-u8-set! bv 0 #x7f)
  265. (bytevector-u8-set! bv 1 (char->integer #\E))
  266. (bytevector-u8-set! bv 2 (char->integer #\L))
  267. (bytevector-u8-set! bv 3 (char->integer #\F))
  268. (bytevector-u8-set! bv 4 class)
  269. (bytevector-u8-set! bv 5 data)
  270. (bytevector-u8-set! bv 6 EV_CURRENT)
  271. (bytevector-u8-set! bv 7 abi)
  272. (bytevector-u8-set! bv 8 0) ; ABI version
  273. (bytevector-u8-set! bv 9 0) ; Pad to 16 bytes.
  274. (bytevector-u8-set! bv 10 0)
  275. (bytevector-u8-set! bv 11 0)
  276. (bytevector-u8-set! bv 12 0)
  277. (bytevector-u8-set! bv 13 0)
  278. (bytevector-u8-set! bv 14 0)
  279. (bytevector-u8-set! bv 15 0))
  280. (define (write-elf32-header bv elf)
  281. (let ((byte-order (elf-byte-order elf)))
  282. (write-elf-ident bv ELFCLASS32
  283. (case byte-order
  284. ((little) ELFDATA2LSB)
  285. ((big) ELFDATA2MSB)
  286. (else (error "unknown endianness" byte-order)))
  287. (elf-abi elf))
  288. (bytevector-u16-set! bv 16 (elf-type elf) byte-order)
  289. (bytevector-u16-set! bv 18 (elf-machine-type elf) byte-order)
  290. (bytevector-u32-set! bv 20 EV_CURRENT byte-order)
  291. (bytevector-u32-set! bv 24 (elf-entry elf) byte-order)
  292. (bytevector-u32-set! bv 28 (elf-phoff elf) byte-order)
  293. (bytevector-u32-set! bv 32 (elf-shoff elf) byte-order)
  294. (bytevector-u32-set! bv 36 (elf-flags elf) byte-order)
  295. (bytevector-u16-set! bv 40 (elf-ehsize elf) byte-order)
  296. (bytevector-u16-set! bv 42 (elf-phentsize elf) byte-order)
  297. (bytevector-u16-set! bv 44 (elf-phnum elf) byte-order)
  298. (bytevector-u16-set! bv 46 (elf-shentsize elf) byte-order)
  299. (bytevector-u16-set! bv 48 (elf-shnum elf) byte-order)
  300. (bytevector-u16-set! bv 50 (elf-shstrndx elf) byte-order)))
  301. (define (parse-elf64 bv byte-order)
  302. (make-elf bv 8 byte-order
  303. (bytevector-u8-ref bv 7)
  304. (bytevector-u16-ref bv 16 byte-order)
  305. (bytevector-u16-ref bv 18 byte-order)
  306. (bytevector-u64-ref bv 24 byte-order)
  307. (bytevector-u64-ref bv 32 byte-order)
  308. (bytevector-u64-ref bv 40 byte-order)
  309. (bytevector-u32-ref bv 48 byte-order)
  310. (bytevector-u16-ref bv 52 byte-order)
  311. (bytevector-u16-ref bv 54 byte-order)
  312. (bytevector-u16-ref bv 56 byte-order)
  313. (bytevector-u16-ref bv 58 byte-order)
  314. (bytevector-u16-ref bv 60 byte-order)
  315. (bytevector-u16-ref bv 62 byte-order)))
  316. (define (write-elf64-header bv elf)
  317. (let ((byte-order (elf-byte-order elf)))
  318. (write-elf-ident bv ELFCLASS64
  319. (case byte-order
  320. ((little) ELFDATA2LSB)
  321. ((big) ELFDATA2MSB)
  322. (else (error "unknown endianness" byte-order)))
  323. (elf-abi elf))
  324. (bytevector-u16-set! bv 16 (elf-type elf) byte-order)
  325. (bytevector-u16-set! bv 18 (elf-machine-type elf) byte-order)
  326. (bytevector-u32-set! bv 20 EV_CURRENT byte-order)
  327. (bytevector-u64-set! bv 24 (elf-entry elf) byte-order)
  328. (bytevector-u64-set! bv 32 (elf-phoff elf) byte-order)
  329. (bytevector-u64-set! bv 40 (elf-shoff elf) byte-order)
  330. (bytevector-u32-set! bv 48 (elf-flags elf) byte-order)
  331. (bytevector-u16-set! bv 52 (elf-ehsize elf) byte-order)
  332. (bytevector-u16-set! bv 54 (elf-phentsize elf) byte-order)
  333. (bytevector-u16-set! bv 56 (elf-phnum elf) byte-order)
  334. (bytevector-u16-set! bv 58 (elf-shentsize elf) byte-order)
  335. (bytevector-u16-set! bv 60 (elf-shnum elf) byte-order)
  336. (bytevector-u16-set! bv 62 (elf-shstrndx elf) byte-order)))
  337. (define (parse-elf bv)
  338. (cond
  339. ((has-elf-header? bv)
  340. (let ((class (bytevector-u8-ref bv 4))
  341. (byte-order (let ((data (bytevector-u8-ref bv 5)))
  342. (cond
  343. ((= data ELFDATA2LSB) (endianness little))
  344. ((= data ELFDATA2MSB) (endianness big))
  345. (else (error "unhandled byte order" data))))))
  346. (cond
  347. ((= class ELFCLASS32) (parse-elf32 bv byte-order))
  348. ((= class ELFCLASS64) (parse-elf64 bv byte-order))
  349. (else (error "unhandled class" class)))))
  350. (else
  351. (error "Invalid ELF" bv))))
  352. (define* (write-elf-header bv elf)
  353. ((case (elf-word-size elf)
  354. ((4) write-elf32-header)
  355. ((8) write-elf64-header)
  356. (else (error "unknown word size" (elf-word-size elf))))
  357. bv elf))
  358. ;;
  359. ;; Segment types
  360. ;;
  361. (define PT_NULL 0) ; Program header table entry unused
  362. (define PT_LOAD 1) ; Loadable program segment
  363. (define PT_DYNAMIC 2) ; Dynamic linking information
  364. (define PT_INTERP 3) ; Program interpreter
  365. (define PT_NOTE 4) ; Auxiliary information
  366. (define PT_SHLIB 5) ; Reserved
  367. (define PT_PHDR 6) ; Entry for header table itself
  368. (define PT_TLS 7) ; Thread-local storage segment
  369. (define PT_NUM 8) ; Number of defined types
  370. (define PT_LOOS #x60000000) ; Start of OS-specific
  371. (define PT_GNU_EH_FRAME #x6474e550) ; GCC .eh_frame_hdr segment
  372. (define PT_GNU_STACK #x6474e551) ; Indicates stack executability
  373. (define PT_GNU_RELRO #x6474e552) ; Read-only after relocation
  374. ;;
  375. ;; Segment flags
  376. ;;
  377. (define PF_X (ash 1 0)) ; Segment is executable
  378. (define PF_W (ash 1 1)) ; Segment is writable
  379. (define PF_R (ash 1 2)) ; Segment is readable
  380. (define-record-type <elf-segment>
  381. (make-elf-segment index type offset vaddr paddr filesz memsz flags align)
  382. elf-segment?
  383. (index elf-segment-index)
  384. (type elf-segment-type)
  385. (offset elf-segment-offset)
  386. (vaddr elf-segment-vaddr)
  387. (paddr elf-segment-paddr)
  388. (filesz elf-segment-filesz)
  389. (memsz elf-segment-memsz)
  390. (flags elf-segment-flags)
  391. (align elf-segment-align))
  392. (define* (make-elf-segment* #:key (index -1) (type PT_LOAD) (offset 0) (vaddr 0)
  393. (paddr 0) (filesz 0) (memsz filesz)
  394. (flags (logior PF_W PF_R))
  395. (align 8))
  396. (make-elf-segment index type offset vaddr paddr filesz memsz flags align))
  397. ;; typedef struct {
  398. ;; uint32_t p_type;
  399. ;; Elf32_Off p_offset;
  400. ;; Elf32_Addr p_vaddr;
  401. ;; Elf32_Addr p_paddr;
  402. ;; uint32_t p_filesz;
  403. ;; uint32_t p_memsz;
  404. ;; uint32_t p_flags;
  405. ;; uint32_t p_align;
  406. ;; } Elf32_Phdr;
  407. (define (parse-elf32-program-header index bv offset byte-order)
  408. (if (<= (+ offset 32) (bytevector-length bv))
  409. (make-elf-segment index
  410. (bytevector-u32-ref bv offset byte-order)
  411. (bytevector-u32-ref bv (+ offset 4) byte-order)
  412. (bytevector-u32-ref bv (+ offset 8) byte-order)
  413. (bytevector-u32-ref bv (+ offset 12) byte-order)
  414. (bytevector-u32-ref bv (+ offset 16) byte-order)
  415. (bytevector-u32-ref bv (+ offset 20) byte-order)
  416. (bytevector-u32-ref bv (+ offset 24) byte-order)
  417. (bytevector-u32-ref bv (+ offset 28) byte-order))
  418. (error "corrupt ELF (offset out of range)" offset)))
  419. (define (write-elf32-program-header bv offset byte-order seg)
  420. (bytevector-u32-set! bv offset (elf-segment-type seg) byte-order)
  421. (bytevector-u32-set! bv (+ offset 4) (elf-segment-offset seg) byte-order)
  422. (bytevector-u32-set! bv (+ offset 8) (elf-segment-vaddr seg) byte-order)
  423. (bytevector-u32-set! bv (+ offset 12) (elf-segment-paddr seg) byte-order)
  424. (bytevector-u32-set! bv (+ offset 16) (elf-segment-filesz seg) byte-order)
  425. (bytevector-u32-set! bv (+ offset 20) (elf-segment-memsz seg) byte-order)
  426. (bytevector-u32-set! bv (+ offset 24) (elf-segment-flags seg) byte-order)
  427. (bytevector-u32-set! bv (+ offset 28) (elf-segment-align seg) byte-order))
  428. ;; typedef struct {
  429. ;; uint32_t p_type;
  430. ;; uint32_t p_flags;
  431. ;; Elf64_Off p_offset;
  432. ;; Elf64_Addr p_vaddr;
  433. ;; Elf64_Addr p_paddr;
  434. ;; uint64_t p_filesz;
  435. ;; uint64_t p_memsz;
  436. ;; uint64_t p_align;
  437. ;; } Elf64_Phdr;
  438. ;; NB: position of `flags' is different!
  439. (define (parse-elf64-program-header index bv offset byte-order)
  440. (if (<= (+ offset 56) (bytevector-length bv))
  441. (make-elf-segment index
  442. (bytevector-u32-ref bv offset byte-order)
  443. (bytevector-u64-ref bv (+ offset 8) byte-order)
  444. (bytevector-u64-ref bv (+ offset 16) byte-order)
  445. (bytevector-u64-ref bv (+ offset 24) byte-order)
  446. (bytevector-u64-ref bv (+ offset 32) byte-order)
  447. (bytevector-u64-ref bv (+ offset 40) byte-order)
  448. (bytevector-u32-ref bv (+ offset 4) byte-order)
  449. (bytevector-u64-ref bv (+ offset 48) byte-order))
  450. (error "corrupt ELF (offset out of range)" offset)))
  451. (define (write-elf64-program-header bv offset byte-order seg)
  452. (bytevector-u32-set! bv offset (elf-segment-type seg) byte-order)
  453. (bytevector-u64-set! bv (+ offset 8) (elf-segment-offset seg) byte-order)
  454. (bytevector-u64-set! bv (+ offset 16) (elf-segment-vaddr seg) byte-order)
  455. (bytevector-u64-set! bv (+ offset 24) (elf-segment-paddr seg) byte-order)
  456. (bytevector-u64-set! bv (+ offset 32) (elf-segment-filesz seg) byte-order)
  457. (bytevector-u64-set! bv (+ offset 40) (elf-segment-memsz seg) byte-order)
  458. (bytevector-u32-set! bv (+ offset 4) (elf-segment-flags seg) byte-order)
  459. (bytevector-u64-set! bv (+ offset 48) (elf-segment-align seg) byte-order))
  460. (define (write-elf-program-header bv offset byte-order word-size seg)
  461. ((case word-size
  462. ((4) write-elf32-program-header)
  463. ((8) write-elf64-program-header)
  464. (else (error "invalid word size" word-size)))
  465. bv offset byte-order seg))
  466. (define (elf-program-header-len word-size)
  467. (case word-size
  468. ((4) 32)
  469. ((8) 56)
  470. (else (error "bad word size" word-size))))
  471. (define (elf-segment elf n)
  472. (if (not (< -1 n (elf-phnum elf)))
  473. (error "bad segment number" n))
  474. ((case (elf-word-size elf)
  475. ((4) parse-elf32-program-header)
  476. ((8) parse-elf64-program-header)
  477. (else (error "unhandled pointer size")))
  478. (elf-bytes elf)
  479. (+ (elf-phoff elf) (* n (elf-phentsize elf)))
  480. (elf-byte-order elf)))
  481. (define (elf-segments elf)
  482. (let lp ((n (elf-phnum elf)) (out '()))
  483. (if (zero? n)
  484. out
  485. (lp (1- n) (cons (elf-segment elf (1- n)) out)))))
  486. (define-record-type <elf-section>
  487. (make-elf-section index name type flags
  488. addr offset size link info addralign entsize)
  489. elf-section?
  490. (index elf-section-index)
  491. (name elf-section-name)
  492. (type elf-section-type)
  493. (flags elf-section-flags)
  494. (addr elf-section-addr)
  495. (offset elf-section-offset)
  496. (size elf-section-size)
  497. (link elf-section-link)
  498. (info elf-section-info)
  499. (addralign elf-section-addralign)
  500. (entsize elf-section-entsize))
  501. (define* (make-elf-section* #:key (index SHN_UNDEF) (name 0) (type SHT_PROGBITS)
  502. (flags SHF_ALLOC) (addr 0) (offset 0) (size 0)
  503. (link 0) (info 0) (addralign 8) (entsize 0))
  504. (make-elf-section index name type flags addr offset size link info addralign
  505. entsize))
  506. ;; typedef struct {
  507. ;; uint32_t sh_name;
  508. ;; uint32_t sh_type;
  509. ;; uint32_t sh_flags;
  510. ;; Elf32_Addr sh_addr;
  511. ;; Elf32_Off sh_offset;
  512. ;; uint32_t sh_size;
  513. ;; uint32_t sh_link;
  514. ;; uint32_t sh_info;
  515. ;; uint32_t sh_addralign;
  516. ;; uint32_t sh_entsize;
  517. ;; } Elf32_Shdr;
  518. (define (parse-elf32-section-header index bv offset byte-order)
  519. (if (<= (+ offset 40) (bytevector-length bv))
  520. (make-elf-section index
  521. (bytevector-u32-ref bv offset byte-order)
  522. (bytevector-u32-ref bv (+ offset 4) byte-order)
  523. (bytevector-u32-ref bv (+ offset 8) byte-order)
  524. (bytevector-u32-ref bv (+ offset 12) byte-order)
  525. (bytevector-u32-ref bv (+ offset 16) byte-order)
  526. (bytevector-u32-ref bv (+ offset 20) byte-order)
  527. (bytevector-u32-ref bv (+ offset 24) byte-order)
  528. (bytevector-u32-ref bv (+ offset 28) byte-order)
  529. (bytevector-u32-ref bv (+ offset 32) byte-order)
  530. (bytevector-u32-ref bv (+ offset 36) byte-order))
  531. (error "corrupt ELF (offset out of range)" offset)))
  532. (define (write-elf32-section-header bv offset byte-order sec)
  533. (bytevector-u32-set! bv offset (elf-section-name sec) byte-order)
  534. (bytevector-u32-set! bv (+ offset 4) (elf-section-type sec) byte-order)
  535. (bytevector-u32-set! bv (+ offset 8) (elf-section-flags sec) byte-order)
  536. (bytevector-u32-set! bv (+ offset 12) (elf-section-addr sec) byte-order)
  537. (bytevector-u32-set! bv (+ offset 16) (elf-section-offset sec) byte-order)
  538. (bytevector-u32-set! bv (+ offset 20) (elf-section-size sec) byte-order)
  539. (bytevector-u32-set! bv (+ offset 24) (elf-section-link sec) byte-order)
  540. (bytevector-u32-set! bv (+ offset 28) (elf-section-info sec) byte-order)
  541. (bytevector-u32-set! bv (+ offset 32) (elf-section-addralign sec) byte-order)
  542. (bytevector-u32-set! bv (+ offset 36) (elf-section-entsize sec) byte-order))
  543. ;; typedef struct {
  544. ;; uint32_t sh_name;
  545. ;; uint32_t sh_type;
  546. ;; uint64_t sh_flags;
  547. ;; Elf64_Addr sh_addr;
  548. ;; Elf64_Off sh_offset;
  549. ;; uint64_t sh_size;
  550. ;; uint32_t sh_link;
  551. ;; uint32_t sh_info;
  552. ;; uint64_t sh_addralign;
  553. ;; uint64_t sh_entsize;
  554. ;; } Elf64_Shdr;
  555. (define (elf-section-header-len word-size)
  556. (case word-size
  557. ((4) 40)
  558. ((8) 64)
  559. (else (error "bad word size" word-size))))
  560. (define (elf-section-header-addr-offset word-size)
  561. (case word-size
  562. ((4) 12)
  563. ((8) 16)
  564. (else (error "bad word size" word-size))))
  565. (define (elf-section-header-offset-offset word-size)
  566. (case word-size
  567. ((4) 16)
  568. ((8) 24)
  569. (else (error "bad word size" word-size))))
  570. (define (parse-elf64-section-header index bv offset byte-order)
  571. (if (<= (+ offset 64) (bytevector-length bv))
  572. (make-elf-section index
  573. (bytevector-u32-ref bv offset byte-order)
  574. (bytevector-u32-ref bv (+ offset 4) byte-order)
  575. (bytevector-u64-ref bv (+ offset 8) byte-order)
  576. (bytevector-u64-ref bv (+ offset 16) byte-order)
  577. (bytevector-u64-ref bv (+ offset 24) byte-order)
  578. (bytevector-u64-ref bv (+ offset 32) byte-order)
  579. (bytevector-u32-ref bv (+ offset 40) byte-order)
  580. (bytevector-u32-ref bv (+ offset 44) byte-order)
  581. (bytevector-u64-ref bv (+ offset 48) byte-order)
  582. (bytevector-u64-ref bv (+ offset 56) byte-order))
  583. (error "corrupt ELF (offset out of range)" offset)))
  584. (define (write-elf64-section-header bv offset byte-order sec)
  585. (bytevector-u32-set! bv offset (elf-section-name sec) byte-order)
  586. (bytevector-u32-set! bv (+ offset 4) (elf-section-type sec) byte-order)
  587. (bytevector-u64-set! bv (+ offset 8) (elf-section-flags sec) byte-order)
  588. (bytevector-u64-set! bv (+ offset 16) (elf-section-addr sec) byte-order)
  589. (bytevector-u64-set! bv (+ offset 24) (elf-section-offset sec) byte-order)
  590. (bytevector-u64-set! bv (+ offset 32) (elf-section-size sec) byte-order)
  591. (bytevector-u32-set! bv (+ offset 40) (elf-section-link sec) byte-order)
  592. (bytevector-u32-set! bv (+ offset 44) (elf-section-info sec) byte-order)
  593. (bytevector-u64-set! bv (+ offset 48) (elf-section-addralign sec) byte-order)
  594. (bytevector-u64-set! bv (+ offset 56) (elf-section-entsize sec) byte-order))
  595. (define (elf-section elf n)
  596. (if (not (< -1 n (elf-shnum elf)))
  597. (error "bad section number" n))
  598. ((case (elf-word-size elf)
  599. ((4) parse-elf32-section-header)
  600. ((8) parse-elf64-section-header)
  601. (else (error "unhandled pointer size")))
  602. n
  603. (elf-bytes elf)
  604. (+ (elf-shoff elf) (* n (elf-shentsize elf)))
  605. (elf-byte-order elf)))
  606. (define (write-elf-section-header bv offset byte-order word-size sec)
  607. ((case word-size
  608. ((4) write-elf32-section-header)
  609. ((8) write-elf64-section-header)
  610. (else (error "invalid word size" word-size)))
  611. bv offset byte-order sec))
  612. (define (elf-sections elf)
  613. (let lp ((n (elf-shnum elf)) (out '()))
  614. (if (zero? n)
  615. out
  616. (lp (1- n) (cons (elf-section elf (1- n)) out)))))
  617. ;;
  618. ;; Section Types
  619. ;;
  620. (define SHT_NULL 0) ; Section header table entry unused
  621. (define SHT_PROGBITS 1) ; Program data
  622. (define SHT_SYMTAB 2) ; Symbol table
  623. (define SHT_STRTAB 3) ; String table
  624. (define SHT_RELA 4) ; Relocation entries with addends
  625. (define SHT_HASH 5) ; Symbol hash table
  626. (define SHT_DYNAMIC 6) ; Dynamic linking information
  627. (define SHT_NOTE 7) ; Notes
  628. (define SHT_NOBITS 8) ; Program space with no data (bss)
  629. (define SHT_REL 9) ; Relocation entries, no addends
  630. (define SHT_SHLIB 10) ; Reserved
  631. (define SHT_DYNSYM 11) ; Dynamic linker symbol table
  632. (define SHT_INIT_ARRAY 14) ; Array of constructors
  633. (define SHT_FINI_ARRAY 15) ; Array of destructors
  634. (define SHT_PREINIT_ARRAY 16) ; Array of pre-constructors
  635. (define SHT_GROUP 17) ; Section group
  636. (define SHT_SYMTAB_SHNDX 18) ; Extended section indeces
  637. (define SHT_NUM 19) ; Number of defined types.
  638. (define SHT_LOOS #x60000000) ; Start OS-specific.
  639. (define SHT_HIOS #x6fffffff) ; End OS-specific type
  640. (define SHT_LOPROC #x70000000) ; Start of processor-specific
  641. (define SHT_HIPROC #x7fffffff) ; End of processor-specific
  642. (define SHT_LOUSER #x80000000) ; Start of application-specific
  643. (define SHT_HIUSER #x8fffffff) ; End of application-specific
  644. ;;
  645. ;; Section Flags
  646. ;;
  647. (define SHF_WRITE (ash 1 0)) ; Writable
  648. (define SHF_ALLOC (ash 1 1)) ; Occupies memory during execution
  649. (define SHF_EXECINSTR (ash 1 2)) ; Executable
  650. (define SHF_MERGE (ash 1 4)) ; Might be merged
  651. (define SHF_STRINGS (ash 1 5)) ; Contains nul-terminated strings
  652. (define SHF_INFO_LINK (ash 1 6)) ; `sh_info' contains SHT index
  653. (define SHF_LINK_ORDER (ash 1 7)) ; Preserve order after combining
  654. (define SHF_OS_NONCONFORMING (ash 1 8)) ; Non-standard OS specific handling required
  655. (define SHF_GROUP (ash 1 9)) ; Section is member of a group.
  656. (define SHF_TLS (ash 1 10)) ; Section hold thread-local data.
  657. ;;
  658. ;; Dynamic entry types. The DT_GUILE types are non-standard.
  659. ;;
  660. (define DT_NULL 0) ; Marks end of dynamic section
  661. (define DT_NEEDED 1) ; Name of needed library
  662. (define DT_PLTRELSZ 2) ; Size in bytes of PLT relocs
  663. (define DT_PLTGOT 3) ; Processor defined value
  664. (define DT_HASH 4) ; Address of symbol hash table
  665. (define DT_STRTAB 5) ; Address of string table
  666. (define DT_SYMTAB 6) ; Address of symbol table
  667. (define DT_RELA 7) ; Address of Rela relocs
  668. (define DT_RELASZ 8) ; Total size of Rela relocs
  669. (define DT_RELAENT 9) ; Size of one Rela reloc
  670. (define DT_STRSZ 10) ; Size of string table
  671. (define DT_SYMENT 11) ; Size of one symbol table entry
  672. (define DT_INIT 12) ; Address of init function
  673. (define DT_FINI 13) ; Address of termination function
  674. (define DT_SONAME 14) ; Name of shared object
  675. (define DT_RPATH 15) ; Library search path (deprecated)
  676. (define DT_SYMBOLIC 16) ; Start symbol search here
  677. (define DT_REL 17) ; Address of Rel relocs
  678. (define DT_RELSZ 18) ; Total size of Rel relocs
  679. (define DT_RELENT 19) ; Size of one Rel reloc
  680. (define DT_PLTREL 20) ; Type of reloc in PLT
  681. (define DT_DEBUG 21) ; For debugging ; unspecified
  682. (define DT_TEXTREL 22) ; Reloc might modify .text
  683. (define DT_JMPREL 23) ; Address of PLT relocs
  684. (define DT_BIND_NOW 24) ; Process relocations of object
  685. (define DT_INIT_ARRAY 25) ; Array with addresses of init fct
  686. (define DT_FINI_ARRAY 26) ; Array with addresses of fini fct
  687. (define DT_INIT_ARRAYSZ 27) ; Size in bytes of DT_INIT_ARRAY
  688. (define DT_FINI_ARRAYSZ 28) ; Size in bytes of DT_FINI_ARRAY
  689. (define DT_RUNPATH 29) ; Library search path
  690. (define DT_FLAGS 30) ; Flags for the object being loaded
  691. (define DT_ENCODING 32) ; Start of encoded range
  692. (define DT_PREINIT_ARRAY 32) ; Array with addresses of preinit fc
  693. (define DT_PREINIT_ARRAYSZ 33) ; size in bytes of DT_PREINIT_ARRAY
  694. (define DT_NUM 34) ; Number used
  695. (define DT_LOGUILE #x37146000) ; Start of Guile-specific
  696. (define DT_GUILE_GC_ROOT #x37146000) ; Offset of GC roots
  697. (define DT_GUILE_GC_ROOT_SZ #x37146001) ; Size in machine words of GC roots
  698. (define DT_GUILE_ENTRY #x37146002) ; Address of entry thunk
  699. (define DT_GUILE_RTL_VERSION #x37146003); Bytecode version
  700. (define DT_HIGUILE #x37146fff) ; End of Guile-specific
  701. (define DT_LOOS #x6000000d) ; Start of OS-specific
  702. (define DT_HIOS #x6ffff000) ; End of OS-specific
  703. (define DT_LOPROC #x70000000) ; Start of processor-specific
  704. (define DT_HIPROC #x7fffffff) ; End of processor-specific
  705. (define (string-table-ref bv offset)
  706. (let lp ((end offset))
  707. (if (zero? (bytevector-u8-ref bv end))
  708. (let ((out (make-bytevector (- end offset))))
  709. (bytevector-copy! bv offset out 0 (- end offset))
  710. (utf8->string out))
  711. (lp (1+ end)))))
  712. (define (elf-section-by-name elf name)
  713. (let ((off (elf-section-offset (elf-section elf (elf-shstrndx elf)))))
  714. (let lp ((n (elf-shnum elf)))
  715. (and (> n 0)
  716. (let ((section (elf-section elf (1- n))))
  717. (if (equal? (string-table-ref (elf-bytes elf)
  718. (+ off (elf-section-name section)))
  719. name)
  720. section
  721. (lp (1- n))))))))
  722. (define (elf-sections-by-name elf)
  723. (let* ((sections (elf-sections elf))
  724. (off (elf-section-offset (list-ref sections (elf-shstrndx elf)))))
  725. (map (lambda (section)
  726. (cons (string-table-ref (elf-bytes elf)
  727. (+ off (elf-section-name section)))
  728. section))
  729. sections)))
  730. (define-record-type <elf-symbol>
  731. (make-elf-symbol name value size info other shndx)
  732. elf-symbol?
  733. (name elf-symbol-name)
  734. (value elf-symbol-value)
  735. (size elf-symbol-size)
  736. (info elf-symbol-info)
  737. (other elf-symbol-other)
  738. (shndx elf-symbol-shndx))
  739. (define* (make-elf-symbol* #:key (name 0) (value 0) (size 0)
  740. (binding STB_LOCAL) (type STT_NOTYPE)
  741. (info (logior (ash binding 4) type))
  742. (visibility STV_DEFAULT) (other visibility)
  743. (shndx SHN_UNDEF))
  744. (make-elf-symbol name value size info other shndx))
  745. ;; typedef struct {
  746. ;; uint32_t st_name;
  747. ;; Elf32_Addr st_value;
  748. ;; uint32_t st_size;
  749. ;; unsigned char st_info;
  750. ;; unsigned char st_other;
  751. ;; uint16_t st_shndx;
  752. ;; } Elf32_Sym;
  753. (define (elf-symbol-len word-size)
  754. (case word-size
  755. ((4) 16)
  756. ((8) 24)
  757. (else (error "bad word size" word-size))))
  758. (define (parse-elf32-symbol bv offset stroff byte-order)
  759. (if (<= (+ offset 16) (bytevector-length bv))
  760. (make-elf-symbol (let ((name (bytevector-u32-ref bv offset byte-order)))
  761. (if stroff
  762. (string-table-ref bv (+ stroff name))
  763. name))
  764. (bytevector-u32-ref bv (+ offset 4) byte-order)
  765. (bytevector-u32-ref bv (+ offset 8) byte-order)
  766. (bytevector-u8-ref bv (+ offset 12))
  767. (bytevector-u8-ref bv (+ offset 13))
  768. (bytevector-u16-ref bv (+ offset 14) byte-order))
  769. (error "corrupt ELF (offset out of range)" offset)))
  770. (define (write-elf32-symbol bv offset byte-order sym)
  771. (bytevector-u32-set! bv offset (elf-symbol-name sym) byte-order)
  772. (bytevector-u32-set! bv (+ offset 4) (elf-symbol-value sym) byte-order)
  773. (bytevector-u32-set! bv (+ offset 8) (elf-symbol-size sym) byte-order)
  774. (bytevector-u8-set! bv (+ offset 12) (elf-symbol-info sym))
  775. (bytevector-u8-set! bv (+ offset 13) (elf-symbol-other sym))
  776. (bytevector-u16-set! bv (+ offset 14) (elf-symbol-shndx sym) byte-order))
  777. ;; typedef struct {
  778. ;; uint32_t st_name;
  779. ;; unsigned char st_info;
  780. ;; unsigned char st_other;
  781. ;; uint16_t st_shndx;
  782. ;; Elf64_Addr st_value;
  783. ;; uint64_t st_size;
  784. ;; } Elf64_Sym;
  785. (define (parse-elf64-symbol bv offset stroff byte-order)
  786. (if (<= (+ offset 24) (bytevector-length bv))
  787. (make-elf-symbol (let ((name (bytevector-u32-ref bv offset byte-order)))
  788. (if stroff
  789. (string-table-ref bv (+ stroff name))
  790. name))
  791. (bytevector-u64-ref bv (+ offset 8) byte-order)
  792. (bytevector-u64-ref bv (+ offset 16) byte-order)
  793. (bytevector-u8-ref bv (+ offset 4))
  794. (bytevector-u8-ref bv (+ offset 5))
  795. (bytevector-u16-ref bv (+ offset 6) byte-order))
  796. (error "corrupt ELF (offset out of range)" offset)))
  797. (define (write-elf64-symbol bv offset byte-order sym)
  798. (bytevector-u32-set! bv offset (elf-symbol-name sym) byte-order)
  799. (bytevector-u8-set! bv (+ offset 4) (elf-symbol-info sym))
  800. (bytevector-u8-set! bv (+ offset 5) (elf-symbol-other sym))
  801. (bytevector-u16-set! bv (+ offset 6) (elf-symbol-shndx sym) byte-order)
  802. (bytevector-u64-set! bv (+ offset 8) (elf-symbol-value sym) byte-order)
  803. (bytevector-u64-set! bv (+ offset 16) (elf-symbol-size sym) byte-order))
  804. (define (write-elf-symbol bv offset byte-order word-size sym)
  805. ((case word-size
  806. ((4) write-elf32-symbol)
  807. ((8) write-elf64-symbol)
  808. (else (error "invalid word size" word-size)))
  809. bv offset byte-order sym))
  810. (define (elf-symbol-table-len section)
  811. (let ((len (elf-section-size section))
  812. (entsize (elf-section-entsize section)))
  813. (unless (and (not (zero? entsize)) (zero? (modulo len entsize)))
  814. (error "bad symbol table" section))
  815. (/ len entsize)))
  816. (define* (elf-symbol-table-ref elf section n #:optional strtab)
  817. (let ((bv (elf-bytes elf))
  818. (byte-order (elf-byte-order elf))
  819. (stroff (and strtab (elf-section-offset strtab)))
  820. (base (elf-section-offset section))
  821. (len (elf-section-size section))
  822. (entsize (elf-section-entsize section)))
  823. (unless (<= (* (1+ n) entsize) len)
  824. (error "out of range symbol table access" section n))
  825. (case (elf-word-size elf)
  826. ((4)
  827. (unless (<= 16 entsize)
  828. (error "bad entsize for symbol table" section))
  829. (parse-elf32-symbol bv (+ base (* n entsize)) stroff byte-order))
  830. ((8)
  831. (unless (<= 24 entsize)
  832. (error "bad entsize for symbol table" section))
  833. (parse-elf64-symbol bv (+ base (* n entsize)) stroff byte-order))
  834. (else (error "bad word size" elf)))))
  835. ;; Legal values for ST_BIND subfield of st_info (symbol binding).
  836. (define STB_LOCAL 0) ; Local symbol
  837. (define STB_GLOBAL 1) ; Global symbol
  838. (define STB_WEAK 2) ; Weak symbol
  839. (define STB_NUM 3) ; Number of defined types.
  840. (define STB_LOOS 10) ; Start of OS-specific
  841. (define STB_GNU_UNIQUE 10) ; Unique symbol.
  842. (define STB_HIOS 12) ; End of OS-specific
  843. (define STB_LOPROC 13) ; Start of processor-specific
  844. (define STB_HIPROC 15) ; End of processor-specific
  845. ;; Legal values for ST_TYPE subfield of st_info (symbol type).
  846. (define STT_NOTYPE 0) ; Symbol type is unspecified
  847. (define STT_OBJECT 1) ; Symbol is a data object
  848. (define STT_FUNC 2) ; Symbol is a code object
  849. (define STT_SECTION 3) ; Symbol associated with a section
  850. (define STT_FILE 4) ; Symbol's name is file name
  851. (define STT_COMMON 5) ; Symbol is a common data object
  852. (define STT_TLS 6) ; Symbol is thread-local data objec
  853. (define STT_NUM 7) ; Number of defined types.
  854. (define STT_LOOS 10) ; Start of OS-specific
  855. (define STT_GNU_IFUNC 10) ; Symbol is indirect code object
  856. (define STT_HIOS 12) ; End of OS-specific
  857. (define STT_LOPROC 13) ; Start of processor-specific
  858. (define STT_HIPROC 15) ; End of processor-specific
  859. ;; Symbol visibility specification encoded in the st_other field.
  860. (define STV_DEFAULT 0) ; Default symbol visibility rules
  861. (define STV_INTERNAL 1) ; Processor specific hidden class
  862. (define STV_HIDDEN 2) ; Sym unavailable in other modules
  863. (define STV_PROTECTED 3) ; Not preemptible, not exported
  864. (define (elf-symbol-binding sym)
  865. (ash (elf-symbol-info sym) -4))
  866. (define (elf-symbol-type sym)
  867. (logand (elf-symbol-info sym) #xf))
  868. (define (elf-symbol-visibility sym)
  869. (logand (elf-symbol-other sym) #x3))
  870. (define NT_GNU_ABI_TAG 1)
  871. (define NT_GNU_HWCAP 2)
  872. (define NT_GNU_BUILD_ID 3)
  873. (define NT_GNU_GOLD_VERSION 4)
  874. (define-record-type <elf-note>
  875. (make-elf-note name desc type)
  876. elf-note?
  877. (name elf-note-name)
  878. (desc elf-note-desc)
  879. (type elf-note-type))
  880. (define (parse-elf-note elf section)
  881. (let ((bv (elf-bytes elf))
  882. (byte-order (elf-byte-order elf))
  883. (offset (elf-section-offset section)))
  884. (unless (<= (+ offset 12) (bytevector-length bv))
  885. (error "corrupt ELF (offset out of range)" offset))
  886. (let ((namesz (bytevector-u32-ref bv offset byte-order))
  887. (descsz (bytevector-u32-ref bv (+ offset 4) byte-order))
  888. (type (bytevector-u32-ref bv (+ offset 8) byte-order)))
  889. (unless (<= (+ offset 12 namesz descsz) (bytevector-length bv))
  890. (error "corrupt ELF (offset out of range)" offset))
  891. (let ((name (make-bytevector (1- namesz)))
  892. (desc (make-bytevector descsz)))
  893. (bytevector-copy! bv (+ offset 12) name 0 (1- namesz))
  894. (bytevector-copy! bv (+ offset 12 namesz) desc 0 descsz)
  895. (make-elf-note (utf8->string name) desc type)))))