modpost.c 55 KB

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  1. /* Postprocess module symbol versions
  2. *
  3. * Copyright 2003 Kai Germaschewski
  4. * Copyright 2002-2004 Rusty Russell, IBM Corporation
  5. * Copyright 2006-2008 Sam Ravnborg
  6. * Based in part on module-init-tools/depmod.c,file2alias
  7. *
  8. * This software may be used and distributed according to the terms
  9. * of the GNU General Public License, incorporated herein by reference.
  10. *
  11. * Usage: modpost vmlinux module1.o module2.o ...
  12. */
  13. #define _GNU_SOURCE
  14. #include <stdio.h>
  15. #include <ctype.h>
  16. #include "modpost.h"
  17. #include "../../include/generated/autoconf.h"
  18. #include "../../include/linux/license.h"
  19. /* Some toolchains use a `_' prefix for all user symbols. */
  20. #ifdef CONFIG_SYMBOL_PREFIX
  21. #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
  22. #else
  23. #define MODULE_SYMBOL_PREFIX ""
  24. #endif
  25. /* Are we using CONFIG_MODVERSIONS? */
  26. int modversions = 0;
  27. /* Warn about undefined symbols? (do so if we have vmlinux) */
  28. int have_vmlinux = 0;
  29. /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  30. static int all_versions = 0;
  31. /* If we are modposting external module set to 1 */
  32. static int external_module = 0;
  33. /* Warn about section mismatch in vmlinux if set to 1 */
  34. static int vmlinux_section_warnings = 1;
  35. /* Only warn about unresolved symbols */
  36. static int warn_unresolved = 0;
  37. /* How a symbol is exported */
  38. static int sec_mismatch_count = 0;
  39. static int sec_mismatch_verbose = 1;
  40. enum export {
  41. export_plain, export_unused, export_gpl,
  42. export_unused_gpl, export_gpl_future, export_unknown
  43. };
  44. #define PRINTF __attribute__ ((format (printf, 1, 2)))
  45. PRINTF void fatal(const char *fmt, ...)
  46. {
  47. va_list arglist;
  48. fprintf(stderr, "FATAL: ");
  49. va_start(arglist, fmt);
  50. vfprintf(stderr, fmt, arglist);
  51. va_end(arglist);
  52. exit(1);
  53. }
  54. PRINTF void warn(const char *fmt, ...)
  55. {
  56. va_list arglist;
  57. fprintf(stderr, "WARNING: ");
  58. va_start(arglist, fmt);
  59. vfprintf(stderr, fmt, arglist);
  60. va_end(arglist);
  61. }
  62. PRINTF void merror(const char *fmt, ...)
  63. {
  64. va_list arglist;
  65. fprintf(stderr, "ERROR: ");
  66. va_start(arglist, fmt);
  67. vfprintf(stderr, fmt, arglist);
  68. va_end(arglist);
  69. }
  70. static int is_vmlinux(const char *modname)
  71. {
  72. const char *myname;
  73. myname = strrchr(modname, '/');
  74. if (myname)
  75. myname++;
  76. else
  77. myname = modname;
  78. return (strcmp(myname, "vmlinux") == 0) ||
  79. (strcmp(myname, "vmlinux.o") == 0);
  80. }
  81. void *do_nofail(void *ptr, const char *expr)
  82. {
  83. if (!ptr)
  84. fatal("modpost: Memory allocation failure: %s.\n", expr);
  85. return ptr;
  86. }
  87. /* A list of all modules we processed */
  88. static struct module *modules;
  89. static struct module *find_module(char *modname)
  90. {
  91. struct module *mod;
  92. for (mod = modules; mod; mod = mod->next)
  93. if (strcmp(mod->name, modname) == 0)
  94. break;
  95. return mod;
  96. }
  97. static struct module *new_module(char *modname)
  98. {
  99. struct module *mod;
  100. char *p, *s;
  101. mod = NOFAIL(malloc(sizeof(*mod)));
  102. memset(mod, 0, sizeof(*mod));
  103. p = NOFAIL(strdup(modname));
  104. /* strip trailing .o */
  105. s = strrchr(p, '.');
  106. if (s != NULL)
  107. if (strcmp(s, ".o") == 0)
  108. *s = '\0';
  109. /* add to list */
  110. mod->name = p;
  111. mod->gpl_compatible = -1;
  112. mod->next = modules;
  113. modules = mod;
  114. return mod;
  115. }
  116. /* A hash of all exported symbols,
  117. * struct symbol is also used for lists of unresolved symbols */
  118. #define SYMBOL_HASH_SIZE 1024
  119. struct symbol {
  120. struct symbol *next;
  121. struct module *module;
  122. unsigned int crc;
  123. int crc_valid;
  124. unsigned int weak:1;
  125. unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
  126. unsigned int kernel:1; /* 1 if symbol is from kernel
  127. * (only for external modules) **/
  128. unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
  129. enum export export; /* Type of export */
  130. char name[0];
  131. };
  132. static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
  133. /* This is based on the hash agorithm from gdbm, via tdb */
  134. static inline unsigned int tdb_hash(const char *name)
  135. {
  136. unsigned value; /* Used to compute the hash value. */
  137. unsigned i; /* Used to cycle through random values. */
  138. /* Set the initial value from the key size. */
  139. for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
  140. value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
  141. return (1103515243 * value + 12345);
  142. }
  143. /**
  144. * Allocate a new symbols for use in the hash of exported symbols or
  145. * the list of unresolved symbols per module
  146. **/
  147. static struct symbol *alloc_symbol(const char *name, unsigned int weak,
  148. struct symbol *next)
  149. {
  150. struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
  151. memset(s, 0, sizeof(*s));
  152. strcpy(s->name, name);
  153. s->weak = weak;
  154. s->next = next;
  155. return s;
  156. }
  157. /* For the hash of exported symbols */
  158. static struct symbol *new_symbol(const char *name, struct module *module,
  159. enum export export)
  160. {
  161. unsigned int hash;
  162. struct symbol *new;
  163. hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
  164. new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
  165. new->module = module;
  166. new->export = export;
  167. return new;
  168. }
  169. static struct symbol *find_symbol(const char *name)
  170. {
  171. struct symbol *s;
  172. /* For our purposes, .foo matches foo. PPC64 needs this. */
  173. if (name[0] == '.')
  174. name++;
  175. for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
  176. if (strcmp(s->name, name) == 0)
  177. return s;
  178. }
  179. return NULL;
  180. }
  181. static struct {
  182. const char *str;
  183. enum export export;
  184. } export_list[] = {
  185. { .str = "EXPORT_SYMBOL", .export = export_plain },
  186. { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
  187. { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
  188. { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
  189. { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
  190. { .str = "(unknown)", .export = export_unknown },
  191. };
  192. static const char *export_str(enum export ex)
  193. {
  194. return export_list[ex].str;
  195. }
  196. static enum export export_no(const char *s)
  197. {
  198. int i;
  199. if (!s)
  200. return export_unknown;
  201. for (i = 0; export_list[i].export != export_unknown; i++) {
  202. if (strcmp(export_list[i].str, s) == 0)
  203. return export_list[i].export;
  204. }
  205. return export_unknown;
  206. }
  207. static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
  208. {
  209. if (sec == elf->export_sec)
  210. return export_plain;
  211. else if (sec == elf->export_unused_sec)
  212. return export_unused;
  213. else if (sec == elf->export_gpl_sec)
  214. return export_gpl;
  215. else if (sec == elf->export_unused_gpl_sec)
  216. return export_unused_gpl;
  217. else if (sec == elf->export_gpl_future_sec)
  218. return export_gpl_future;
  219. else
  220. return export_unknown;
  221. }
  222. /**
  223. * Add an exported symbol - it may have already been added without a
  224. * CRC, in this case just update the CRC
  225. **/
  226. static struct symbol *sym_add_exported(const char *name, struct module *mod,
  227. enum export export)
  228. {
  229. struct symbol *s = find_symbol(name);
  230. if (!s) {
  231. s = new_symbol(name, mod, export);
  232. } else {
  233. if (!s->preloaded) {
  234. warn("%s: '%s' exported twice. Previous export "
  235. "was in %s%s\n", mod->name, name,
  236. s->module->name,
  237. is_vmlinux(s->module->name) ?"":".ko");
  238. } else {
  239. /* In case Modules.symvers was out of date */
  240. s->module = mod;
  241. }
  242. }
  243. s->preloaded = 0;
  244. s->vmlinux = is_vmlinux(mod->name);
  245. s->kernel = 0;
  246. s->export = export;
  247. return s;
  248. }
  249. static void sym_update_crc(const char *name, struct module *mod,
  250. unsigned int crc, enum export export)
  251. {
  252. struct symbol *s = find_symbol(name);
  253. if (!s)
  254. s = new_symbol(name, mod, export);
  255. s->crc = crc;
  256. s->crc_valid = 1;
  257. }
  258. void *grab_file(const char *filename, unsigned long *size)
  259. {
  260. struct stat st;
  261. void *map;
  262. int fd;
  263. fd = open(filename, O_RDONLY);
  264. if (fd < 0 || fstat(fd, &st) != 0)
  265. return NULL;
  266. *size = st.st_size;
  267. map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
  268. close(fd);
  269. if (map == MAP_FAILED)
  270. return NULL;
  271. return map;
  272. }
  273. /**
  274. * Return a copy of the next line in a mmap'ed file.
  275. * spaces in the beginning of the line is trimmed away.
  276. * Return a pointer to a static buffer.
  277. **/
  278. char *get_next_line(unsigned long *pos, void *file, unsigned long size)
  279. {
  280. static char line[4096];
  281. int skip = 1;
  282. size_t len = 0;
  283. signed char *p = (signed char *)file + *pos;
  284. char *s = line;
  285. for (; *pos < size ; (*pos)++) {
  286. if (skip && isspace(*p)) {
  287. p++;
  288. continue;
  289. }
  290. skip = 0;
  291. if (*p != '\n' && (*pos < size)) {
  292. len++;
  293. *s++ = *p++;
  294. if (len > 4095)
  295. break; /* Too long, stop */
  296. } else {
  297. /* End of string */
  298. *s = '\0';
  299. return line;
  300. }
  301. }
  302. /* End of buffer */
  303. return NULL;
  304. }
  305. void release_file(void *file, unsigned long size)
  306. {
  307. munmap(file, size);
  308. }
  309. static int parse_elf(struct elf_info *info, const char *filename)
  310. {
  311. unsigned int i;
  312. Elf_Ehdr *hdr;
  313. Elf_Shdr *sechdrs;
  314. Elf_Sym *sym;
  315. const char *secstrings;
  316. unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
  317. hdr = grab_file(filename, &info->size);
  318. if (!hdr) {
  319. perror(filename);
  320. exit(1);
  321. }
  322. info->hdr = hdr;
  323. if (info->size < sizeof(*hdr)) {
  324. /* file too small, assume this is an empty .o file */
  325. return 0;
  326. }
  327. /* Is this a valid ELF file? */
  328. if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
  329. (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
  330. (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
  331. (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
  332. /* Not an ELF file - silently ignore it */
  333. return 0;
  334. }
  335. /* Fix endianness in ELF header */
  336. hdr->e_type = TO_NATIVE(hdr->e_type);
  337. hdr->e_machine = TO_NATIVE(hdr->e_machine);
  338. hdr->e_version = TO_NATIVE(hdr->e_version);
  339. hdr->e_entry = TO_NATIVE(hdr->e_entry);
  340. hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
  341. hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
  342. hdr->e_flags = TO_NATIVE(hdr->e_flags);
  343. hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
  344. hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
  345. hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
  346. hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
  347. hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
  348. hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
  349. sechdrs = (void *)hdr + hdr->e_shoff;
  350. info->sechdrs = sechdrs;
  351. /* Check if file offset is correct */
  352. if (hdr->e_shoff > info->size) {
  353. fatal("section header offset=%lu in file '%s' is bigger than "
  354. "filesize=%lu\n", (unsigned long)hdr->e_shoff,
  355. filename, info->size);
  356. return 0;
  357. }
  358. if (hdr->e_shnum == 0) {
  359. /*
  360. * There are more than 64k sections,
  361. * read count from .sh_size.
  362. * note: it doesn't need shndx2secindex()
  363. */
  364. info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
  365. }
  366. else {
  367. info->num_sections = hdr->e_shnum;
  368. }
  369. if (hdr->e_shstrndx == SHN_XINDEX) {
  370. info->secindex_strings =
  371. shndx2secindex(TO_NATIVE(sechdrs[0].sh_link));
  372. }
  373. else {
  374. info->secindex_strings = hdr->e_shstrndx;
  375. }
  376. /* Fix endianness in section headers */
  377. for (i = 0; i < info->num_sections; i++) {
  378. sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
  379. sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
  380. sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
  381. sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
  382. sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
  383. sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
  384. sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
  385. sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
  386. sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
  387. sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
  388. }
  389. /* Find symbol table. */
  390. secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
  391. for (i = 1; i < info->num_sections; i++) {
  392. const char *secname;
  393. int nobits = sechdrs[i].sh_type == SHT_NOBITS;
  394. if (!nobits && sechdrs[i].sh_offset > info->size) {
  395. fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
  396. "sizeof(*hrd)=%zu\n", filename,
  397. (unsigned long)sechdrs[i].sh_offset,
  398. sizeof(*hdr));
  399. return 0;
  400. }
  401. secname = secstrings + sechdrs[i].sh_name;
  402. if (strcmp(secname, ".modinfo") == 0) {
  403. if (nobits)
  404. fatal("%s has NOBITS .modinfo\n", filename);
  405. info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
  406. info->modinfo_len = sechdrs[i].sh_size;
  407. } else if (strcmp(secname, "__ksymtab") == 0)
  408. info->export_sec = i;
  409. else if (strcmp(secname, "__ksymtab_unused") == 0)
  410. info->export_unused_sec = i;
  411. else if (strcmp(secname, "__ksymtab_gpl") == 0)
  412. info->export_gpl_sec = i;
  413. else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
  414. info->export_unused_gpl_sec = i;
  415. else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
  416. info->export_gpl_future_sec = i;
  417. if (sechdrs[i].sh_type == SHT_SYMTAB) {
  418. unsigned int sh_link_idx;
  419. symtab_idx = i;
  420. info->symtab_start = (void *)hdr +
  421. sechdrs[i].sh_offset;
  422. info->symtab_stop = (void *)hdr +
  423. sechdrs[i].sh_offset + sechdrs[i].sh_size;
  424. sh_link_idx = shndx2secindex(sechdrs[i].sh_link);
  425. info->strtab = (void *)hdr +
  426. sechdrs[sh_link_idx].sh_offset;
  427. }
  428. /* 32bit section no. table? ("more than 64k sections") */
  429. if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
  430. symtab_shndx_idx = i;
  431. info->symtab_shndx_start = (void *)hdr +
  432. sechdrs[i].sh_offset;
  433. info->symtab_shndx_stop = (void *)hdr +
  434. sechdrs[i].sh_offset + sechdrs[i].sh_size;
  435. }
  436. }
  437. if (!info->symtab_start)
  438. fatal("%s has no symtab?\n", filename);
  439. /* Fix endianness in symbols */
  440. for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
  441. sym->st_shndx = TO_NATIVE(sym->st_shndx);
  442. sym->st_name = TO_NATIVE(sym->st_name);
  443. sym->st_value = TO_NATIVE(sym->st_value);
  444. sym->st_size = TO_NATIVE(sym->st_size);
  445. }
  446. if (symtab_shndx_idx != ~0U) {
  447. Elf32_Word *p;
  448. if (symtab_idx !=
  449. shndx2secindex(sechdrs[symtab_shndx_idx].sh_link))
  450. fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
  451. filename,
  452. shndx2secindex(sechdrs[symtab_shndx_idx].sh_link),
  453. symtab_idx);
  454. /* Fix endianness */
  455. for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
  456. p++)
  457. *p = TO_NATIVE(*p);
  458. }
  459. return 1;
  460. }
  461. static void parse_elf_finish(struct elf_info *info)
  462. {
  463. release_file(info->hdr, info->size);
  464. }
  465. static int ignore_undef_symbol(struct elf_info *info, const char *symname)
  466. {
  467. /* ignore __this_module, it will be resolved shortly */
  468. if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
  469. return 1;
  470. /* ignore global offset table */
  471. if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
  472. return 1;
  473. if (info->hdr->e_machine == EM_PPC)
  474. /* Special register function linked on all modules during final link of .ko */
  475. if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
  476. strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
  477. strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
  478. strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
  479. return 1;
  480. if (info->hdr->e_machine == EM_PPC64)
  481. /* Special register function linked on all modules during final link of .ko */
  482. if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
  483. strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
  484. return 1;
  485. /* Do not ignore this symbol */
  486. return 0;
  487. }
  488. #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
  489. #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
  490. static void handle_modversions(struct module *mod, struct elf_info *info,
  491. Elf_Sym *sym, const char *symname)
  492. {
  493. unsigned int crc;
  494. enum export export = export_from_sec(info, get_secindex(info, sym));
  495. switch (sym->st_shndx) {
  496. case SHN_COMMON:
  497. warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
  498. break;
  499. case SHN_ABS:
  500. /* CRC'd symbol */
  501. if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
  502. crc = (unsigned int) sym->st_value;
  503. sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
  504. export);
  505. }
  506. break;
  507. case SHN_UNDEF:
  508. /* undefined symbol */
  509. if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
  510. ELF_ST_BIND(sym->st_info) != STB_WEAK)
  511. break;
  512. if (ignore_undef_symbol(info, symname))
  513. break;
  514. /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
  515. #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
  516. /* add compatibility with older glibc */
  517. #ifndef STT_SPARC_REGISTER
  518. #define STT_SPARC_REGISTER STT_REGISTER
  519. #endif
  520. if (info->hdr->e_machine == EM_SPARC ||
  521. info->hdr->e_machine == EM_SPARCV9) {
  522. /* Ignore register directives. */
  523. if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
  524. break;
  525. if (symname[0] == '.') {
  526. char *munged = strdup(symname);
  527. munged[0] = '_';
  528. munged[1] = toupper(munged[1]);
  529. symname = munged;
  530. }
  531. }
  532. #endif
  533. if (memcmp(symname, MODULE_SYMBOL_PREFIX,
  534. strlen(MODULE_SYMBOL_PREFIX)) == 0) {
  535. mod->unres =
  536. alloc_symbol(symname +
  537. strlen(MODULE_SYMBOL_PREFIX),
  538. ELF_ST_BIND(sym->st_info) == STB_WEAK,
  539. mod->unres);
  540. }
  541. break;
  542. default:
  543. /* All exported symbols */
  544. if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
  545. sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
  546. export);
  547. }
  548. if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
  549. mod->has_init = 1;
  550. if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
  551. mod->has_cleanup = 1;
  552. break;
  553. }
  554. }
  555. /**
  556. * Parse tag=value strings from .modinfo section
  557. **/
  558. static char *next_string(char *string, unsigned long *secsize)
  559. {
  560. /* Skip non-zero chars */
  561. while (string[0]) {
  562. string++;
  563. if ((*secsize)-- <= 1)
  564. return NULL;
  565. }
  566. /* Skip any zero padding. */
  567. while (!string[0]) {
  568. string++;
  569. if ((*secsize)-- <= 1)
  570. return NULL;
  571. }
  572. return string;
  573. }
  574. static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
  575. const char *tag, char *info)
  576. {
  577. char *p;
  578. unsigned int taglen = strlen(tag);
  579. unsigned long size = modinfo_len;
  580. if (info) {
  581. size -= info - (char *)modinfo;
  582. modinfo = next_string(info, &size);
  583. }
  584. for (p = modinfo; p; p = next_string(p, &size)) {
  585. if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
  586. return p + taglen + 1;
  587. }
  588. return NULL;
  589. }
  590. static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
  591. const char *tag)
  592. {
  593. return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
  594. }
  595. /**
  596. * Test if string s ends in string sub
  597. * return 0 if match
  598. **/
  599. static int strrcmp(const char *s, const char *sub)
  600. {
  601. int slen, sublen;
  602. if (!s || !sub)
  603. return 1;
  604. slen = strlen(s);
  605. sublen = strlen(sub);
  606. if ((slen == 0) || (sublen == 0))
  607. return 1;
  608. if (sublen > slen)
  609. return 1;
  610. return memcmp(s + slen - sublen, sub, sublen);
  611. }
  612. static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
  613. {
  614. if (sym)
  615. return elf->strtab + sym->st_name;
  616. else
  617. return "(unknown)";
  618. }
  619. static const char *sec_name(struct elf_info *elf, int secindex)
  620. {
  621. Elf_Shdr *sechdrs = elf->sechdrs;
  622. return (void *)elf->hdr +
  623. elf->sechdrs[elf->secindex_strings].sh_offset +
  624. sechdrs[secindex].sh_name;
  625. }
  626. static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
  627. {
  628. return (void *)elf->hdr +
  629. elf->sechdrs[elf->secindex_strings].sh_offset +
  630. sechdr->sh_name;
  631. }
  632. /* if sym is empty or point to a string
  633. * like ".[0-9]+" then return 1.
  634. * This is the optional prefix added by ld to some sections
  635. */
  636. static int number_prefix(const char *sym)
  637. {
  638. if (*sym++ == '\0')
  639. return 1;
  640. if (*sym != '.')
  641. return 0;
  642. do {
  643. char c = *sym++;
  644. if (c < '0' || c > '9')
  645. return 0;
  646. } while (*sym);
  647. return 1;
  648. }
  649. /* The pattern is an array of simple patterns.
  650. * "foo" will match an exact string equal to "foo"
  651. * "*foo" will match a string that ends with "foo"
  652. * "foo*" will match a string that begins with "foo"
  653. * "foo$" will match a string equal to "foo" or "foo.1"
  654. * where the '1' can be any number including several digits.
  655. * The $ syntax is for sections where ld append a dot number
  656. * to make section name unique.
  657. */
  658. static int match(const char *sym, const char * const pat[])
  659. {
  660. const char *p;
  661. while (*pat) {
  662. p = *pat++;
  663. const char *endp = p + strlen(p) - 1;
  664. /* "*foo" */
  665. if (*p == '*') {
  666. if (strrcmp(sym, p + 1) == 0)
  667. return 1;
  668. }
  669. /* "foo*" */
  670. else if (*endp == '*') {
  671. if (strncmp(sym, p, strlen(p) - 1) == 0)
  672. return 1;
  673. }
  674. /* "foo$" */
  675. else if (*endp == '$') {
  676. if (strncmp(sym, p, strlen(p) - 1) == 0) {
  677. if (number_prefix(sym + strlen(p) - 1))
  678. return 1;
  679. }
  680. }
  681. /* no wildcards */
  682. else {
  683. if (strcmp(p, sym) == 0)
  684. return 1;
  685. }
  686. }
  687. /* no match */
  688. return 0;
  689. }
  690. /* sections that we do not want to do full section mismatch check on */
  691. static const char *section_white_list[] =
  692. {
  693. ".comment*",
  694. ".debug*",
  695. ".mdebug*", /* alpha, score, mips etc. */
  696. ".pdr", /* alpha, score, mips etc. */
  697. ".stab*",
  698. ".note*",
  699. ".got*",
  700. ".toc*",
  701. NULL
  702. };
  703. /*
  704. * This is used to find sections missing the SHF_ALLOC flag.
  705. * The cause of this is often a section specified in assembler
  706. * without "ax" / "aw".
  707. */
  708. static void check_section(const char *modname, struct elf_info *elf,
  709. Elf_Shdr *sechdr)
  710. {
  711. const char *sec = sech_name(elf, sechdr);
  712. if (sechdr->sh_type == SHT_PROGBITS &&
  713. !(sechdr->sh_flags & SHF_ALLOC) &&
  714. !match(sec, section_white_list)) {
  715. warn("%s (%s): unexpected non-allocatable section.\n"
  716. "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
  717. "Note that for example <linux/init.h> contains\n"
  718. "section definitions for use in .S files.\n\n",
  719. modname, sec);
  720. }
  721. }
  722. #define ALL_INIT_DATA_SECTIONS \
  723. ".init.setup$", ".init.rodata$", \
  724. ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
  725. ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
  726. #define ALL_EXIT_DATA_SECTIONS \
  727. ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
  728. #define ALL_INIT_TEXT_SECTIONS \
  729. ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
  730. #define ALL_EXIT_TEXT_SECTIONS \
  731. ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
  732. #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
  733. MEM_INIT_SECTIONS
  734. #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
  735. MEM_EXIT_SECTIONS
  736. #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
  737. #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
  738. #define DATA_SECTIONS ".data$", ".data.rel$"
  739. #define TEXT_SECTIONS ".text$"
  740. #define INIT_SECTIONS ".init.*"
  741. #define DEV_INIT_SECTIONS ".devinit.*"
  742. #define CPU_INIT_SECTIONS ".cpuinit.*"
  743. #define MEM_INIT_SECTIONS ".meminit.*"
  744. #define EXIT_SECTIONS ".exit.*"
  745. #define DEV_EXIT_SECTIONS ".devexit.*"
  746. #define CPU_EXIT_SECTIONS ".cpuexit.*"
  747. #define MEM_EXIT_SECTIONS ".memexit.*"
  748. /* init data sections */
  749. static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
  750. /* all init sections */
  751. static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
  752. /* All init and exit sections (code + data) */
  753. static const char *init_exit_sections[] =
  754. {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
  755. /* data section */
  756. static const char *data_sections[] = { DATA_SECTIONS, NULL };
  757. /* symbols in .data that may refer to init/exit sections */
  758. #define DEFAULT_SYMBOL_WHITE_LIST \
  759. "*driver", \
  760. "*_template", /* scsi uses *_template a lot */ \
  761. "*_timer", /* arm uses ops structures named _timer a lot */ \
  762. "*_sht", /* scsi also used *_sht to some extent */ \
  763. "*_ops", \
  764. "*_probe", \
  765. "*_probe_one", \
  766. "*_console"
  767. static const char *head_sections[] = { ".head.text*", NULL };
  768. static const char *linker_symbols[] =
  769. { "__init_begin", "_sinittext", "_einittext", NULL };
  770. enum mismatch {
  771. TEXT_TO_ANY_INIT,
  772. DATA_TO_ANY_INIT,
  773. TEXT_TO_ANY_EXIT,
  774. DATA_TO_ANY_EXIT,
  775. XXXINIT_TO_SOME_INIT,
  776. XXXEXIT_TO_SOME_EXIT,
  777. ANY_INIT_TO_ANY_EXIT,
  778. ANY_EXIT_TO_ANY_INIT,
  779. EXPORT_TO_INIT_EXIT,
  780. };
  781. struct sectioncheck {
  782. const char *fromsec[20];
  783. const char *tosec[20];
  784. enum mismatch mismatch;
  785. const char *symbol_white_list[20];
  786. };
  787. const struct sectioncheck sectioncheck[] = {
  788. /* Do not reference init/exit code/data from
  789. * normal code and data
  790. */
  791. {
  792. .fromsec = { TEXT_SECTIONS, NULL },
  793. .tosec = { ALL_INIT_SECTIONS, NULL },
  794. .mismatch = TEXT_TO_ANY_INIT,
  795. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  796. },
  797. {
  798. .fromsec = { DATA_SECTIONS, NULL },
  799. .tosec = { ALL_XXXINIT_SECTIONS, NULL },
  800. .mismatch = DATA_TO_ANY_INIT,
  801. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  802. },
  803. {
  804. .fromsec = { DATA_SECTIONS, NULL },
  805. .tosec = { INIT_SECTIONS, NULL },
  806. .mismatch = DATA_TO_ANY_INIT,
  807. .symbol_white_list = {
  808. "*_template", "*_timer", "*_sht", "*_ops",
  809. "*_probe", "*_probe_one", "*_console", NULL
  810. },
  811. },
  812. {
  813. .fromsec = { TEXT_SECTIONS, NULL },
  814. .tosec = { ALL_EXIT_SECTIONS, NULL },
  815. .mismatch = TEXT_TO_ANY_EXIT,
  816. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  817. },
  818. {
  819. .fromsec = { DATA_SECTIONS, NULL },
  820. .tosec = { ALL_EXIT_SECTIONS, NULL },
  821. .mismatch = DATA_TO_ANY_EXIT,
  822. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  823. },
  824. /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
  825. {
  826. .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
  827. .tosec = { INIT_SECTIONS, NULL },
  828. .mismatch = XXXINIT_TO_SOME_INIT,
  829. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  830. },
  831. /* Do not reference cpuinit code/data from meminit code/data */
  832. {
  833. .fromsec = { MEM_INIT_SECTIONS, NULL },
  834. .tosec = { CPU_INIT_SECTIONS, NULL },
  835. .mismatch = XXXINIT_TO_SOME_INIT,
  836. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  837. },
  838. /* Do not reference meminit code/data from cpuinit code/data */
  839. {
  840. .fromsec = { CPU_INIT_SECTIONS, NULL },
  841. .tosec = { MEM_INIT_SECTIONS, NULL },
  842. .mismatch = XXXINIT_TO_SOME_INIT,
  843. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  844. },
  845. /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
  846. {
  847. .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
  848. .tosec = { EXIT_SECTIONS, NULL },
  849. .mismatch = XXXEXIT_TO_SOME_EXIT,
  850. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  851. },
  852. /* Do not reference cpuexit code/data from memexit code/data */
  853. {
  854. .fromsec = { MEM_EXIT_SECTIONS, NULL },
  855. .tosec = { CPU_EXIT_SECTIONS, NULL },
  856. .mismatch = XXXEXIT_TO_SOME_EXIT,
  857. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  858. },
  859. /* Do not reference memexit code/data from cpuexit code/data */
  860. {
  861. .fromsec = { CPU_EXIT_SECTIONS, NULL },
  862. .tosec = { MEM_EXIT_SECTIONS, NULL },
  863. .mismatch = XXXEXIT_TO_SOME_EXIT,
  864. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  865. },
  866. /* Do not use exit code/data from init code */
  867. {
  868. .fromsec = { ALL_INIT_SECTIONS, NULL },
  869. .tosec = { ALL_EXIT_SECTIONS, NULL },
  870. .mismatch = ANY_INIT_TO_ANY_EXIT,
  871. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  872. },
  873. /* Do not use init code/data from exit code */
  874. {
  875. .fromsec = { ALL_EXIT_SECTIONS, NULL },
  876. .tosec = { ALL_INIT_SECTIONS, NULL },
  877. .mismatch = ANY_EXIT_TO_ANY_INIT,
  878. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  879. },
  880. /* Do not export init/exit functions or data */
  881. {
  882. .fromsec = { "__ksymtab*", NULL },
  883. .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
  884. .mismatch = EXPORT_TO_INIT_EXIT,
  885. .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
  886. }
  887. };
  888. static const struct sectioncheck *section_mismatch(
  889. const char *fromsec, const char *tosec)
  890. {
  891. int i;
  892. int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
  893. const struct sectioncheck *check = &sectioncheck[0];
  894. for (i = 0; i < elems; i++) {
  895. if (match(fromsec, check->fromsec) &&
  896. match(tosec, check->tosec))
  897. return check;
  898. check++;
  899. }
  900. return NULL;
  901. }
  902. /**
  903. * Whitelist to allow certain references to pass with no warning.
  904. *
  905. * Pattern 1:
  906. * If a module parameter is declared __initdata and permissions=0
  907. * then this is legal despite the warning generated.
  908. * We cannot see value of permissions here, so just ignore
  909. * this pattern.
  910. * The pattern is identified by:
  911. * tosec = .init.data
  912. * fromsec = .data*
  913. * atsym =__param*
  914. *
  915. * Pattern 2:
  916. * Many drivers utilise a *driver container with references to
  917. * add, remove, probe functions etc.
  918. * These functions may often be marked __devinit and we do not want to
  919. * warn here.
  920. * the pattern is identified by:
  921. * tosec = init or exit section
  922. * fromsec = data section
  923. * atsym = *driver, *_template, *_sht, *_ops, *_probe,
  924. * *probe_one, *_console, *_timer
  925. *
  926. * Pattern 3:
  927. * Whitelist all references from .head.text to any init section
  928. *
  929. * Pattern 4:
  930. * Some symbols belong to init section but still it is ok to reference
  931. * these from non-init sections as these symbols don't have any memory
  932. * allocated for them and symbol address and value are same. So even
  933. * if init section is freed, its ok to reference those symbols.
  934. * For ex. symbols marking the init section boundaries.
  935. * This pattern is identified by
  936. * refsymname = __init_begin, _sinittext, _einittext
  937. *
  938. **/
  939. static int secref_whitelist(const struct sectioncheck *mismatch,
  940. const char *fromsec, const char *fromsym,
  941. const char *tosec, const char *tosym)
  942. {
  943. /* Check for pattern 1 */
  944. if (match(tosec, init_data_sections) &&
  945. match(fromsec, data_sections) &&
  946. (strncmp(fromsym, "__param", strlen("__param")) == 0))
  947. return 0;
  948. /* Check for pattern 2 */
  949. if (match(tosec, init_exit_sections) &&
  950. match(fromsec, data_sections) &&
  951. match(fromsym, mismatch->symbol_white_list))
  952. return 0;
  953. /* Check for pattern 3 */
  954. if (match(fromsec, head_sections) &&
  955. match(tosec, init_sections))
  956. return 0;
  957. /* Check for pattern 4 */
  958. if (match(tosym, linker_symbols))
  959. return 0;
  960. return 1;
  961. }
  962. /**
  963. * Find symbol based on relocation record info.
  964. * In some cases the symbol supplied is a valid symbol so
  965. * return refsym. If st_name != 0 we assume this is a valid symbol.
  966. * In other cases the symbol needs to be looked up in the symbol table
  967. * based on section and address.
  968. * **/
  969. static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
  970. Elf_Sym *relsym)
  971. {
  972. Elf_Sym *sym;
  973. Elf_Sym *near = NULL;
  974. Elf64_Sword distance = 20;
  975. Elf64_Sword d;
  976. unsigned int relsym_secindex;
  977. if (relsym->st_name != 0)
  978. return relsym;
  979. relsym_secindex = get_secindex(elf, relsym);
  980. for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
  981. if (get_secindex(elf, sym) != relsym_secindex)
  982. continue;
  983. if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
  984. continue;
  985. if (sym->st_value == addr)
  986. return sym;
  987. /* Find a symbol nearby - addr are maybe negative */
  988. d = sym->st_value - addr;
  989. if (d < 0)
  990. d = addr - sym->st_value;
  991. if (d < distance) {
  992. distance = d;
  993. near = sym;
  994. }
  995. }
  996. /* We need a close match */
  997. if (distance < 20)
  998. return near;
  999. else
  1000. return NULL;
  1001. }
  1002. static inline int is_arm_mapping_symbol(const char *str)
  1003. {
  1004. return str[0] == '$' && strchr("atd", str[1])
  1005. && (str[2] == '\0' || str[2] == '.');
  1006. }
  1007. /*
  1008. * If there's no name there, ignore it; likewise, ignore it if it's
  1009. * one of the magic symbols emitted used by current ARM tools.
  1010. *
  1011. * Otherwise if find_symbols_between() returns those symbols, they'll
  1012. * fail the whitelist tests and cause lots of false alarms ... fixable
  1013. * only by merging __exit and __init sections into __text, bloating
  1014. * the kernel (which is especially evil on embedded platforms).
  1015. */
  1016. static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
  1017. {
  1018. const char *name = elf->strtab + sym->st_name;
  1019. if (!name || !strlen(name))
  1020. return 0;
  1021. return !is_arm_mapping_symbol(name);
  1022. }
  1023. /*
  1024. * Find symbols before or equal addr and after addr - in the section sec.
  1025. * If we find two symbols with equal offset prefer one with a valid name.
  1026. * The ELF format may have a better way to detect what type of symbol
  1027. * it is, but this works for now.
  1028. **/
  1029. static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
  1030. const char *sec)
  1031. {
  1032. Elf_Sym *sym;
  1033. Elf_Sym *near = NULL;
  1034. Elf_Addr distance = ~0;
  1035. for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
  1036. const char *symsec;
  1037. if (is_shndx_special(sym->st_shndx))
  1038. continue;
  1039. symsec = sec_name(elf, get_secindex(elf, sym));
  1040. if (strcmp(symsec, sec) != 0)
  1041. continue;
  1042. if (!is_valid_name(elf, sym))
  1043. continue;
  1044. if (sym->st_value <= addr) {
  1045. if ((addr - sym->st_value) < distance) {
  1046. distance = addr - sym->st_value;
  1047. near = sym;
  1048. } else if ((addr - sym->st_value) == distance) {
  1049. near = sym;
  1050. }
  1051. }
  1052. }
  1053. return near;
  1054. }
  1055. /*
  1056. * Convert a section name to the function/data attribute
  1057. * .init.text => __init
  1058. * .cpuinit.data => __cpudata
  1059. * .memexitconst => __memconst
  1060. * etc.
  1061. */
  1062. static char *sec2annotation(const char *s)
  1063. {
  1064. if (match(s, init_exit_sections)) {
  1065. char *p = malloc(20);
  1066. char *r = p;
  1067. *p++ = '_';
  1068. *p++ = '_';
  1069. if (*s == '.')
  1070. s++;
  1071. while (*s && *s != '.')
  1072. *p++ = *s++;
  1073. *p = '\0';
  1074. if (*s == '.')
  1075. s++;
  1076. if (strstr(s, "rodata") != NULL)
  1077. strcat(p, "const ");
  1078. else if (strstr(s, "data") != NULL)
  1079. strcat(p, "data ");
  1080. else
  1081. strcat(p, " ");
  1082. return r; /* we leak her but we do not care */
  1083. } else {
  1084. return "";
  1085. }
  1086. }
  1087. static int is_function(Elf_Sym *sym)
  1088. {
  1089. if (sym)
  1090. return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
  1091. else
  1092. return -1;
  1093. }
  1094. /*
  1095. * Print a warning about a section mismatch.
  1096. * Try to find symbols near it so user can find it.
  1097. * Check whitelist before warning - it may be a false positive.
  1098. */
  1099. static void report_sec_mismatch(const char *modname,
  1100. const struct sectioncheck *mismatch,
  1101. const char *fromsec,
  1102. unsigned long long fromaddr,
  1103. const char *fromsym,
  1104. int from_is_func,
  1105. const char *tosec, const char *tosym,
  1106. int to_is_func)
  1107. {
  1108. const char *from, *from_p;
  1109. const char *to, *to_p;
  1110. char *prl_from;
  1111. char *prl_to;
  1112. switch (from_is_func) {
  1113. case 0: from = "variable"; from_p = ""; break;
  1114. case 1: from = "function"; from_p = "()"; break;
  1115. default: from = "(unknown reference)"; from_p = ""; break;
  1116. }
  1117. switch (to_is_func) {
  1118. case 0: to = "variable"; to_p = ""; break;
  1119. case 1: to = "function"; to_p = "()"; break;
  1120. default: to = "(unknown reference)"; to_p = ""; break;
  1121. }
  1122. sec_mismatch_count++;
  1123. if (!sec_mismatch_verbose)
  1124. return;
  1125. warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
  1126. "to the %s %s:%s%s\n",
  1127. modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
  1128. tosym, to_p);
  1129. switch (mismatch->mismatch) {
  1130. case TEXT_TO_ANY_INIT:
  1131. prl_from = sec2annotation(fromsec);
  1132. prl_to = sec2annotation(tosec);
  1133. fprintf(stderr,
  1134. "The function %s%s() references\n"
  1135. "the %s %s%s%s.\n"
  1136. "This is often because %s lacks a %s\n"
  1137. "annotation or the annotation of %s is wrong.\n",
  1138. prl_from, fromsym,
  1139. to, prl_to, tosym, to_p,
  1140. fromsym, prl_to, tosym);
  1141. free(prl_from);
  1142. free(prl_to);
  1143. break;
  1144. case DATA_TO_ANY_INIT: {
  1145. prl_to = sec2annotation(tosec);
  1146. const char *const *s = mismatch->symbol_white_list;
  1147. fprintf(stderr,
  1148. "The variable %s references\n"
  1149. "the %s %s%s%s\n"
  1150. "If the reference is valid then annotate the\n"
  1151. "variable with __init* or __refdata (see linux/init.h) "
  1152. "or name the variable:\n",
  1153. fromsym, to, prl_to, tosym, to_p);
  1154. while (*s)
  1155. fprintf(stderr, "%s, ", *s++);
  1156. fprintf(stderr, "\n");
  1157. free(prl_to);
  1158. break;
  1159. }
  1160. case TEXT_TO_ANY_EXIT:
  1161. prl_to = sec2annotation(tosec);
  1162. fprintf(stderr,
  1163. "The function %s() references a %s in an exit section.\n"
  1164. "Often the %s %s%s has valid usage outside the exit section\n"
  1165. "and the fix is to remove the %sannotation of %s.\n",
  1166. fromsym, to, to, tosym, to_p, prl_to, tosym);
  1167. free(prl_to);
  1168. break;
  1169. case DATA_TO_ANY_EXIT: {
  1170. prl_to = sec2annotation(tosec);
  1171. const char *const *s = mismatch->symbol_white_list;
  1172. fprintf(stderr,
  1173. "The variable %s references\n"
  1174. "the %s %s%s%s\n"
  1175. "If the reference is valid then annotate the\n"
  1176. "variable with __exit* (see linux/init.h) or "
  1177. "name the variable:\n",
  1178. fromsym, to, prl_to, tosym, to_p);
  1179. while (*s)
  1180. fprintf(stderr, "%s, ", *s++);
  1181. fprintf(stderr, "\n");
  1182. free(prl_to);
  1183. break;
  1184. }
  1185. case XXXINIT_TO_SOME_INIT:
  1186. case XXXEXIT_TO_SOME_EXIT:
  1187. prl_from = sec2annotation(fromsec);
  1188. prl_to = sec2annotation(tosec);
  1189. fprintf(stderr,
  1190. "The %s %s%s%s references\n"
  1191. "a %s %s%s%s.\n"
  1192. "If %s is only used by %s then\n"
  1193. "annotate %s with a matching annotation.\n",
  1194. from, prl_from, fromsym, from_p,
  1195. to, prl_to, tosym, to_p,
  1196. tosym, fromsym, tosym);
  1197. free(prl_from);
  1198. free(prl_to);
  1199. break;
  1200. case ANY_INIT_TO_ANY_EXIT:
  1201. prl_from = sec2annotation(fromsec);
  1202. prl_to = sec2annotation(tosec);
  1203. fprintf(stderr,
  1204. "The %s %s%s%s references\n"
  1205. "a %s %s%s%s.\n"
  1206. "This is often seen when error handling "
  1207. "in the init function\n"
  1208. "uses functionality in the exit path.\n"
  1209. "The fix is often to remove the %sannotation of\n"
  1210. "%s%s so it may be used outside an exit section.\n",
  1211. from, prl_from, fromsym, from_p,
  1212. to, prl_to, tosym, to_p,
  1213. sec2annotation(tosec), tosym, to_p);
  1214. free(prl_from);
  1215. free(prl_to);
  1216. break;
  1217. case ANY_EXIT_TO_ANY_INIT:
  1218. prl_from = sec2annotation(fromsec);
  1219. prl_to = sec2annotation(tosec);
  1220. fprintf(stderr,
  1221. "The %s %s%s%s references\n"
  1222. "a %s %s%s%s.\n"
  1223. "This is often seen when error handling "
  1224. "in the exit function\n"
  1225. "uses functionality in the init path.\n"
  1226. "The fix is often to remove the %sannotation of\n"
  1227. "%s%s so it may be used outside an init section.\n",
  1228. from, prl_from, fromsym, from_p,
  1229. to, prl_to, tosym, to_p,
  1230. prl_to, tosym, to_p);
  1231. free(prl_from);
  1232. free(prl_to);
  1233. break;
  1234. case EXPORT_TO_INIT_EXIT:
  1235. prl_to = sec2annotation(tosec);
  1236. fprintf(stderr,
  1237. "The symbol %s is exported and annotated %s\n"
  1238. "Fix this by removing the %sannotation of %s "
  1239. "or drop the export.\n",
  1240. tosym, prl_to, prl_to, tosym);
  1241. free(prl_to);
  1242. break;
  1243. }
  1244. fprintf(stderr, "\n");
  1245. }
  1246. static void check_section_mismatch(const char *modname, struct elf_info *elf,
  1247. Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
  1248. {
  1249. const char *tosec;
  1250. const struct sectioncheck *mismatch;
  1251. tosec = sec_name(elf, get_secindex(elf, sym));
  1252. mismatch = section_mismatch(fromsec, tosec);
  1253. if (mismatch) {
  1254. Elf_Sym *to;
  1255. Elf_Sym *from;
  1256. const char *tosym;
  1257. const char *fromsym;
  1258. from = find_elf_symbol2(elf, r->r_offset, fromsec);
  1259. fromsym = sym_name(elf, from);
  1260. to = find_elf_symbol(elf, r->r_addend, sym);
  1261. tosym = sym_name(elf, to);
  1262. /* check whitelist - we may ignore it */
  1263. if (secref_whitelist(mismatch,
  1264. fromsec, fromsym, tosec, tosym)) {
  1265. report_sec_mismatch(modname, mismatch,
  1266. fromsec, r->r_offset, fromsym,
  1267. is_function(from), tosec, tosym,
  1268. is_function(to));
  1269. }
  1270. }
  1271. }
  1272. static unsigned int *reloc_location(struct elf_info *elf,
  1273. Elf_Shdr *sechdr, Elf_Rela *r)
  1274. {
  1275. Elf_Shdr *sechdrs = elf->sechdrs;
  1276. int section = shndx2secindex(sechdr->sh_info);
  1277. return (void *)elf->hdr + sechdrs[section].sh_offset +
  1278. r->r_offset - sechdrs[section].sh_addr;
  1279. }
  1280. static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
  1281. {
  1282. unsigned int r_typ = ELF_R_TYPE(r->r_info);
  1283. unsigned int *location = reloc_location(elf, sechdr, r);
  1284. switch (r_typ) {
  1285. case R_386_32:
  1286. r->r_addend = TO_NATIVE(*location);
  1287. break;
  1288. case R_386_PC32:
  1289. r->r_addend = TO_NATIVE(*location) + 4;
  1290. /* For CONFIG_RELOCATABLE=y */
  1291. if (elf->hdr->e_type == ET_EXEC)
  1292. r->r_addend += r->r_offset;
  1293. break;
  1294. }
  1295. return 0;
  1296. }
  1297. static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
  1298. {
  1299. unsigned int r_typ = ELF_R_TYPE(r->r_info);
  1300. switch (r_typ) {
  1301. case R_ARM_ABS32:
  1302. /* From ARM ABI: (S + A) | T */
  1303. r->r_addend = (int)(long)
  1304. (elf->symtab_start + ELF_R_SYM(r->r_info));
  1305. break;
  1306. case R_ARM_PC24:
  1307. /* From ARM ABI: ((S + A) | T) - P */
  1308. r->r_addend = (int)(long)(elf->hdr +
  1309. sechdr->sh_offset +
  1310. (r->r_offset - sechdr->sh_addr));
  1311. break;
  1312. default:
  1313. return 1;
  1314. }
  1315. return 0;
  1316. }
  1317. static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
  1318. {
  1319. unsigned int r_typ = ELF_R_TYPE(r->r_info);
  1320. unsigned int *location = reloc_location(elf, sechdr, r);
  1321. unsigned int inst;
  1322. if (r_typ == R_MIPS_HI16)
  1323. return 1; /* skip this */
  1324. inst = TO_NATIVE(*location);
  1325. switch (r_typ) {
  1326. case R_MIPS_LO16:
  1327. r->r_addend = inst & 0xffff;
  1328. break;
  1329. case R_MIPS_26:
  1330. r->r_addend = (inst & 0x03ffffff) << 2;
  1331. break;
  1332. case R_MIPS_32:
  1333. r->r_addend = inst;
  1334. break;
  1335. }
  1336. return 0;
  1337. }
  1338. static void section_rela(const char *modname, struct elf_info *elf,
  1339. Elf_Shdr *sechdr)
  1340. {
  1341. Elf_Sym *sym;
  1342. Elf_Rela *rela;
  1343. Elf_Rela r;
  1344. unsigned int r_sym;
  1345. const char *fromsec;
  1346. Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
  1347. Elf_Rela *stop = (void *)start + sechdr->sh_size;
  1348. fromsec = sech_name(elf, sechdr);
  1349. fromsec += strlen(".rela");
  1350. /* if from section (name) is know good then skip it */
  1351. if (match(fromsec, section_white_list))
  1352. return;
  1353. for (rela = start; rela < stop; rela++) {
  1354. r.r_offset = TO_NATIVE(rela->r_offset);
  1355. #if KERNEL_ELFCLASS == ELFCLASS64
  1356. if (elf->hdr->e_machine == EM_MIPS) {
  1357. unsigned int r_typ;
  1358. r_sym = ELF64_MIPS_R_SYM(rela->r_info);
  1359. r_sym = TO_NATIVE(r_sym);
  1360. r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
  1361. r.r_info = ELF64_R_INFO(r_sym, r_typ);
  1362. } else {
  1363. r.r_info = TO_NATIVE(rela->r_info);
  1364. r_sym = ELF_R_SYM(r.r_info);
  1365. }
  1366. #else
  1367. r.r_info = TO_NATIVE(rela->r_info);
  1368. r_sym = ELF_R_SYM(r.r_info);
  1369. #endif
  1370. r.r_addend = TO_NATIVE(rela->r_addend);
  1371. sym = elf->symtab_start + r_sym;
  1372. /* Skip special sections */
  1373. if (is_shndx_special(sym->st_shndx))
  1374. continue;
  1375. check_section_mismatch(modname, elf, &r, sym, fromsec);
  1376. }
  1377. }
  1378. static void section_rel(const char *modname, struct elf_info *elf,
  1379. Elf_Shdr *sechdr)
  1380. {
  1381. Elf_Sym *sym;
  1382. Elf_Rel *rel;
  1383. Elf_Rela r;
  1384. unsigned int r_sym;
  1385. const char *fromsec;
  1386. Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
  1387. Elf_Rel *stop = (void *)start + sechdr->sh_size;
  1388. fromsec = sech_name(elf, sechdr);
  1389. fromsec += strlen(".rel");
  1390. /* if from section (name) is know good then skip it */
  1391. if (match(fromsec, section_white_list))
  1392. return;
  1393. for (rel = start; rel < stop; rel++) {
  1394. r.r_offset = TO_NATIVE(rel->r_offset);
  1395. #if KERNEL_ELFCLASS == ELFCLASS64
  1396. if (elf->hdr->e_machine == EM_MIPS) {
  1397. unsigned int r_typ;
  1398. r_sym = ELF64_MIPS_R_SYM(rel->r_info);
  1399. r_sym = TO_NATIVE(r_sym);
  1400. r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
  1401. r.r_info = ELF64_R_INFO(r_sym, r_typ);
  1402. } else {
  1403. r.r_info = TO_NATIVE(rel->r_info);
  1404. r_sym = ELF_R_SYM(r.r_info);
  1405. }
  1406. #else
  1407. r.r_info = TO_NATIVE(rel->r_info);
  1408. r_sym = ELF_R_SYM(r.r_info);
  1409. #endif
  1410. r.r_addend = 0;
  1411. switch (elf->hdr->e_machine) {
  1412. case EM_386:
  1413. if (addend_386_rel(elf, sechdr, &r))
  1414. continue;
  1415. break;
  1416. case EM_ARM:
  1417. if (addend_arm_rel(elf, sechdr, &r))
  1418. continue;
  1419. break;
  1420. case EM_MIPS:
  1421. if (addend_mips_rel(elf, sechdr, &r))
  1422. continue;
  1423. break;
  1424. }
  1425. sym = elf->symtab_start + r_sym;
  1426. /* Skip special sections */
  1427. if (is_shndx_special(sym->st_shndx))
  1428. continue;
  1429. check_section_mismatch(modname, elf, &r, sym, fromsec);
  1430. }
  1431. }
  1432. /**
  1433. * A module includes a number of sections that are discarded
  1434. * either when loaded or when used as built-in.
  1435. * For loaded modules all functions marked __init and all data
  1436. * marked __initdata will be discarded when the module has been intialized.
  1437. * Likewise for modules used built-in the sections marked __exit
  1438. * are discarded because __exit marked function are supposed to be called
  1439. * only when a module is unloaded which never happens for built-in modules.
  1440. * The check_sec_ref() function traverses all relocation records
  1441. * to find all references to a section that reference a section that will
  1442. * be discarded and warns about it.
  1443. **/
  1444. static void check_sec_ref(struct module *mod, const char *modname,
  1445. struct elf_info *elf)
  1446. {
  1447. int i;
  1448. Elf_Shdr *sechdrs = elf->sechdrs;
  1449. /* Walk through all sections */
  1450. for (i = 0; i < elf->num_sections; i++) {
  1451. check_section(modname, elf, &elf->sechdrs[i]);
  1452. /* We want to process only relocation sections and not .init */
  1453. if (sechdrs[i].sh_type == SHT_RELA)
  1454. section_rela(modname, elf, &elf->sechdrs[i]);
  1455. else if (sechdrs[i].sh_type == SHT_REL)
  1456. section_rel(modname, elf, &elf->sechdrs[i]);
  1457. }
  1458. }
  1459. static void read_symbols(char *modname)
  1460. {
  1461. const char *symname;
  1462. char *version;
  1463. char *license;
  1464. struct module *mod;
  1465. struct elf_info info = { };
  1466. Elf_Sym *sym;
  1467. if (!parse_elf(&info, modname))
  1468. return;
  1469. mod = new_module(modname);
  1470. /* When there's no vmlinux, don't print warnings about
  1471. * unresolved symbols (since there'll be too many ;) */
  1472. if (is_vmlinux(modname)) {
  1473. have_vmlinux = 1;
  1474. mod->skip = 1;
  1475. }
  1476. license = get_modinfo(info.modinfo, info.modinfo_len, "license");
  1477. if (info.modinfo && !license && !is_vmlinux(modname))
  1478. warn("modpost: missing MODULE_LICENSE() in %s\n"
  1479. "see include/linux/module.h for "
  1480. "more information\n", modname);
  1481. while (license) {
  1482. if (license_is_gpl_compatible(license))
  1483. mod->gpl_compatible = 1;
  1484. else {
  1485. mod->gpl_compatible = 0;
  1486. break;
  1487. }
  1488. license = get_next_modinfo(info.modinfo, info.modinfo_len,
  1489. "license", license);
  1490. }
  1491. for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
  1492. symname = info.strtab + sym->st_name;
  1493. handle_modversions(mod, &info, sym, symname);
  1494. handle_moddevtable(mod, &info, sym, symname);
  1495. }
  1496. if (!is_vmlinux(modname) ||
  1497. (is_vmlinux(modname) && vmlinux_section_warnings))
  1498. check_sec_ref(mod, modname, &info);
  1499. version = get_modinfo(info.modinfo, info.modinfo_len, "version");
  1500. if (version)
  1501. maybe_frob_rcs_version(modname, version, info.modinfo,
  1502. version - (char *)info.hdr);
  1503. if (version || (all_versions && !is_vmlinux(modname)))
  1504. get_src_version(modname, mod->srcversion,
  1505. sizeof(mod->srcversion)-1);
  1506. parse_elf_finish(&info);
  1507. /* Our trick to get versioning for module struct etc. - it's
  1508. * never passed as an argument to an exported function, so
  1509. * the automatic versioning doesn't pick it up, but it's really
  1510. * important anyhow */
  1511. if (modversions)
  1512. mod->unres = alloc_symbol("module_layout", 0, mod->unres);
  1513. }
  1514. #define SZ 500
  1515. /* We first write the generated file into memory using the
  1516. * following helper, then compare to the file on disk and
  1517. * only update the later if anything changed */
  1518. void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
  1519. const char *fmt, ...)
  1520. {
  1521. char tmp[SZ];
  1522. int len;
  1523. va_list ap;
  1524. va_start(ap, fmt);
  1525. len = vsnprintf(tmp, SZ, fmt, ap);
  1526. buf_write(buf, tmp, len);
  1527. va_end(ap);
  1528. }
  1529. void buf_write(struct buffer *buf, const char *s, int len)
  1530. {
  1531. if (buf->size - buf->pos < len) {
  1532. buf->size += len + SZ;
  1533. buf->p = realloc(buf->p, buf->size);
  1534. }
  1535. strncpy(buf->p + buf->pos, s, len);
  1536. buf->pos += len;
  1537. }
  1538. static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
  1539. {
  1540. const char *e = is_vmlinux(m) ?"":".ko";
  1541. switch (exp) {
  1542. case export_gpl:
  1543. fatal("modpost: GPL-incompatible module %s%s "
  1544. "uses GPL-only symbol '%s'\n", m, e, s);
  1545. break;
  1546. case export_unused_gpl:
  1547. fatal("modpost: GPL-incompatible module %s%s "
  1548. "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
  1549. break;
  1550. case export_gpl_future:
  1551. warn("modpost: GPL-incompatible module %s%s "
  1552. "uses future GPL-only symbol '%s'\n", m, e, s);
  1553. break;
  1554. case export_plain:
  1555. case export_unused:
  1556. case export_unknown:
  1557. /* ignore */
  1558. break;
  1559. }
  1560. }
  1561. static void check_for_unused(enum export exp, const char *m, const char *s)
  1562. {
  1563. const char *e = is_vmlinux(m) ?"":".ko";
  1564. switch (exp) {
  1565. case export_unused:
  1566. case export_unused_gpl:
  1567. warn("modpost: module %s%s "
  1568. "uses symbol '%s' marked UNUSED\n", m, e, s);
  1569. break;
  1570. default:
  1571. /* ignore */
  1572. break;
  1573. }
  1574. }
  1575. static void check_exports(struct module *mod)
  1576. {
  1577. struct symbol *s, *exp;
  1578. for (s = mod->unres; s; s = s->next) {
  1579. const char *basename;
  1580. exp = find_symbol(s->name);
  1581. if (!exp || exp->module == mod)
  1582. continue;
  1583. basename = strrchr(mod->name, '/');
  1584. if (basename)
  1585. basename++;
  1586. else
  1587. basename = mod->name;
  1588. if (!mod->gpl_compatible)
  1589. check_for_gpl_usage(exp->export, basename, exp->name);
  1590. check_for_unused(exp->export, basename, exp->name);
  1591. }
  1592. }
  1593. /**
  1594. * Header for the generated file
  1595. **/
  1596. static void add_header(struct buffer *b, struct module *mod)
  1597. {
  1598. buf_printf(b, "#include <linux/module.h>\n");
  1599. buf_printf(b, "#include <linux/vermagic.h>\n");
  1600. buf_printf(b, "#include <linux/compiler.h>\n");
  1601. buf_printf(b, "\n");
  1602. buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
  1603. buf_printf(b, "\n");
  1604. buf_printf(b, "struct module __this_module\n");
  1605. buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
  1606. buf_printf(b, " .name = KBUILD_MODNAME,\n");
  1607. if (mod->has_init)
  1608. buf_printf(b, " .init = init_module,\n");
  1609. if (mod->has_cleanup)
  1610. buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
  1611. " .exit = cleanup_module,\n"
  1612. "#endif\n");
  1613. buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
  1614. buf_printf(b, "};\n");
  1615. }
  1616. static void add_staging_flag(struct buffer *b, const char *name)
  1617. {
  1618. static const char *staging_dir = "drivers/staging";
  1619. if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
  1620. buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
  1621. }
  1622. /**
  1623. * Record CRCs for unresolved symbols
  1624. **/
  1625. static int add_versions(struct buffer *b, struct module *mod)
  1626. {
  1627. struct symbol *s, *exp;
  1628. int err = 0;
  1629. for (s = mod->unres; s; s = s->next) {
  1630. exp = find_symbol(s->name);
  1631. if (!exp || exp->module == mod) {
  1632. if (have_vmlinux && !s->weak) {
  1633. if (warn_unresolved) {
  1634. warn("\"%s\" [%s.ko] undefined!\n",
  1635. s->name, mod->name);
  1636. } else {
  1637. merror("\"%s\" [%s.ko] undefined!\n",
  1638. s->name, mod->name);
  1639. err = 1;
  1640. }
  1641. }
  1642. continue;
  1643. }
  1644. s->module = exp->module;
  1645. s->crc_valid = exp->crc_valid;
  1646. s->crc = exp->crc;
  1647. }
  1648. if (!modversions)
  1649. return err;
  1650. buf_printf(b, "\n");
  1651. buf_printf(b, "static const struct modversion_info ____versions[]\n");
  1652. buf_printf(b, "__used\n");
  1653. buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
  1654. for (s = mod->unres; s; s = s->next) {
  1655. if (!s->module)
  1656. continue;
  1657. if (!s->crc_valid) {
  1658. warn("\"%s\" [%s.ko] has no CRC!\n",
  1659. s->name, mod->name);
  1660. continue;
  1661. }
  1662. buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
  1663. }
  1664. buf_printf(b, "};\n");
  1665. return err;
  1666. }
  1667. static void add_depends(struct buffer *b, struct module *mod,
  1668. struct module *modules)
  1669. {
  1670. struct symbol *s;
  1671. struct module *m;
  1672. int first = 1;
  1673. for (m = modules; m; m = m->next)
  1674. m->seen = is_vmlinux(m->name);
  1675. buf_printf(b, "\n");
  1676. buf_printf(b, "static const char __module_depends[]\n");
  1677. buf_printf(b, "__used\n");
  1678. buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
  1679. buf_printf(b, "\"depends=");
  1680. for (s = mod->unres; s; s = s->next) {
  1681. const char *p;
  1682. if (!s->module)
  1683. continue;
  1684. if (s->module->seen)
  1685. continue;
  1686. s->module->seen = 1;
  1687. p = strrchr(s->module->name, '/');
  1688. if (p)
  1689. p++;
  1690. else
  1691. p = s->module->name;
  1692. buf_printf(b, "%s%s", first ? "" : ",", p);
  1693. first = 0;
  1694. }
  1695. buf_printf(b, "\";\n");
  1696. }
  1697. static void add_srcversion(struct buffer *b, struct module *mod)
  1698. {
  1699. if (mod->srcversion[0]) {
  1700. buf_printf(b, "\n");
  1701. buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
  1702. mod->srcversion);
  1703. }
  1704. }
  1705. static void write_if_changed(struct buffer *b, const char *fname)
  1706. {
  1707. char *tmp;
  1708. FILE *file;
  1709. struct stat st;
  1710. file = fopen(fname, "r");
  1711. if (!file)
  1712. goto write;
  1713. if (fstat(fileno(file), &st) < 0)
  1714. goto close_write;
  1715. if (st.st_size != b->pos)
  1716. goto close_write;
  1717. tmp = NOFAIL(malloc(b->pos));
  1718. if (fread(tmp, 1, b->pos, file) != b->pos)
  1719. goto free_write;
  1720. if (memcmp(tmp, b->p, b->pos) != 0)
  1721. goto free_write;
  1722. free(tmp);
  1723. fclose(file);
  1724. return;
  1725. free_write:
  1726. free(tmp);
  1727. close_write:
  1728. fclose(file);
  1729. write:
  1730. file = fopen(fname, "w");
  1731. if (!file) {
  1732. perror(fname);
  1733. exit(1);
  1734. }
  1735. if (fwrite(b->p, 1, b->pos, file) != b->pos) {
  1736. perror(fname);
  1737. exit(1);
  1738. }
  1739. fclose(file);
  1740. }
  1741. /* parse Module.symvers file. line format:
  1742. * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
  1743. **/
  1744. static void read_dump(const char *fname, unsigned int kernel)
  1745. {
  1746. unsigned long size, pos = 0;
  1747. void *file = grab_file(fname, &size);
  1748. char *line;
  1749. if (!file)
  1750. /* No symbol versions, silently ignore */
  1751. return;
  1752. while ((line = get_next_line(&pos, file, size))) {
  1753. char *symname, *modname, *d, *export, *end;
  1754. unsigned int crc;
  1755. struct module *mod;
  1756. struct symbol *s;
  1757. if (!(symname = strchr(line, '\t')))
  1758. goto fail;
  1759. *symname++ = '\0';
  1760. if (!(modname = strchr(symname, '\t')))
  1761. goto fail;
  1762. *modname++ = '\0';
  1763. if ((export = strchr(modname, '\t')) != NULL)
  1764. *export++ = '\0';
  1765. if (export && ((end = strchr(export, '\t')) != NULL))
  1766. *end = '\0';
  1767. crc = strtoul(line, &d, 16);
  1768. if (*symname == '\0' || *modname == '\0' || *d != '\0')
  1769. goto fail;
  1770. mod = find_module(modname);
  1771. if (!mod) {
  1772. if (is_vmlinux(modname))
  1773. have_vmlinux = 1;
  1774. mod = new_module(modname);
  1775. mod->skip = 1;
  1776. }
  1777. s = sym_add_exported(symname, mod, export_no(export));
  1778. s->kernel = kernel;
  1779. s->preloaded = 1;
  1780. sym_update_crc(symname, mod, crc, export_no(export));
  1781. }
  1782. return;
  1783. fail:
  1784. fatal("parse error in symbol dump file\n");
  1785. }
  1786. /* For normal builds always dump all symbols.
  1787. * For external modules only dump symbols
  1788. * that are not read from kernel Module.symvers.
  1789. **/
  1790. static int dump_sym(struct symbol *sym)
  1791. {
  1792. if (!external_module)
  1793. return 1;
  1794. if (sym->vmlinux || sym->kernel)
  1795. return 0;
  1796. return 1;
  1797. }
  1798. static void write_dump(const char *fname)
  1799. {
  1800. struct buffer buf = { };
  1801. struct symbol *symbol;
  1802. int n;
  1803. for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
  1804. symbol = symbolhash[n];
  1805. while (symbol) {
  1806. if (dump_sym(symbol))
  1807. buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
  1808. symbol->crc, symbol->name,
  1809. symbol->module->name,
  1810. export_str(symbol->export));
  1811. symbol = symbol->next;
  1812. }
  1813. }
  1814. write_if_changed(&buf, fname);
  1815. }
  1816. struct ext_sym_list {
  1817. struct ext_sym_list *next;
  1818. const char *file;
  1819. };
  1820. int main(int argc, char **argv)
  1821. {
  1822. struct module *mod;
  1823. struct buffer buf = { };
  1824. char *kernel_read = NULL, *module_read = NULL;
  1825. char *dump_write = NULL;
  1826. int opt;
  1827. int err;
  1828. struct ext_sym_list *extsym_iter;
  1829. struct ext_sym_list *extsym_start = NULL;
  1830. while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
  1831. switch (opt) {
  1832. case 'i':
  1833. kernel_read = optarg;
  1834. break;
  1835. case 'I':
  1836. module_read = optarg;
  1837. external_module = 1;
  1838. break;
  1839. case 'c':
  1840. cross_build = 1;
  1841. break;
  1842. case 'e':
  1843. external_module = 1;
  1844. extsym_iter =
  1845. NOFAIL(malloc(sizeof(*extsym_iter)));
  1846. extsym_iter->next = extsym_start;
  1847. extsym_iter->file = optarg;
  1848. extsym_start = extsym_iter;
  1849. break;
  1850. case 'm':
  1851. modversions = 1;
  1852. break;
  1853. case 'o':
  1854. dump_write = optarg;
  1855. break;
  1856. case 'a':
  1857. all_versions = 1;
  1858. break;
  1859. case 's':
  1860. vmlinux_section_warnings = 0;
  1861. break;
  1862. case 'S':
  1863. sec_mismatch_verbose = 0;
  1864. break;
  1865. case 'w':
  1866. warn_unresolved = 1;
  1867. break;
  1868. default:
  1869. exit(1);
  1870. }
  1871. }
  1872. if (kernel_read)
  1873. read_dump(kernel_read, 1);
  1874. if (module_read)
  1875. read_dump(module_read, 0);
  1876. while (extsym_start) {
  1877. read_dump(extsym_start->file, 0);
  1878. extsym_iter = extsym_start->next;
  1879. free(extsym_start);
  1880. extsym_start = extsym_iter;
  1881. }
  1882. while (optind < argc)
  1883. read_symbols(argv[optind++]);
  1884. for (mod = modules; mod; mod = mod->next) {
  1885. if (mod->skip)
  1886. continue;
  1887. check_exports(mod);
  1888. }
  1889. err = 0;
  1890. for (mod = modules; mod; mod = mod->next) {
  1891. char fname[strlen(mod->name) + 10];
  1892. if (mod->skip)
  1893. continue;
  1894. buf.pos = 0;
  1895. add_header(&buf, mod);
  1896. add_staging_flag(&buf, mod->name);
  1897. err |= add_versions(&buf, mod);
  1898. add_depends(&buf, mod, modules);
  1899. add_moddevtable(&buf, mod);
  1900. add_srcversion(&buf, mod);
  1901. sprintf(fname, "%s.mod.c", mod->name);
  1902. write_if_changed(&buf, fname);
  1903. }
  1904. if (dump_write)
  1905. write_dump(dump_write);
  1906. if (sec_mismatch_count && !sec_mismatch_verbose)
  1907. warn("modpost: Found %d section mismatch(es).\n"
  1908. "To see full details build your kernel with:\n"
  1909. "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
  1910. sec_mismatch_count);
  1911. return err;
  1912. }