vsprintf.c 50 KB

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  1. /*
  2. * linux/lib/vsprintf.c
  3. *
  4. * Copyright (C) 1991, 1992 Linus Torvalds
  5. */
  6. /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
  7. /*
  8. * Wirzenius wrote this portably, Torvalds fucked it up :-)
  9. */
  10. /*
  11. * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  12. * - changed to provide snprintf and vsnprintf functions
  13. * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  14. * - scnprintf and vscnprintf
  15. */
  16. #include <stdarg.h>
  17. #include <linux/module.h>
  18. #include <linux/types.h>
  19. #include <linux/string.h>
  20. #include <linux/ctype.h>
  21. #include <linux/kernel.h>
  22. #include <linux/kallsyms.h>
  23. #include <linux/uaccess.h>
  24. #include <linux/ioport.h>
  25. #include <net/addrconf.h>
  26. #include <asm/page.h> /* for PAGE_SIZE */
  27. #include <asm/div64.h>
  28. #include <asm/sections.h> /* for dereference_function_descriptor() */
  29. /* Works only for digits and letters, but small and fast */
  30. #define TOLOWER(x) ((x) | 0x20)
  31. static unsigned int simple_guess_base(const char *cp)
  32. {
  33. if (cp[0] == '0') {
  34. if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
  35. return 16;
  36. else
  37. return 8;
  38. } else {
  39. return 10;
  40. }
  41. }
  42. /**
  43. * simple_strtoull - convert a string to an unsigned long long
  44. * @cp: The start of the string
  45. * @endp: A pointer to the end of the parsed string will be placed here
  46. * @base: The number base to use
  47. */
  48. unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
  49. {
  50. unsigned long long result = 0;
  51. if (!base)
  52. base = simple_guess_base(cp);
  53. if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
  54. cp += 2;
  55. while (isxdigit(*cp)) {
  56. unsigned int value;
  57. value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
  58. if (value >= base)
  59. break;
  60. result = result * base + value;
  61. cp++;
  62. }
  63. if (endp)
  64. *endp = (char *)cp;
  65. return result;
  66. }
  67. EXPORT_SYMBOL(simple_strtoull);
  68. /**
  69. * simple_strtoul - convert a string to an unsigned long
  70. * @cp: The start of the string
  71. * @endp: A pointer to the end of the parsed string will be placed here
  72. * @base: The number base to use
  73. */
  74. unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
  75. {
  76. return simple_strtoull(cp, endp, base);
  77. }
  78. EXPORT_SYMBOL(simple_strtoul);
  79. /**
  80. * simple_strtol - convert a string to a signed long
  81. * @cp: The start of the string
  82. * @endp: A pointer to the end of the parsed string will be placed here
  83. * @base: The number base to use
  84. */
  85. long simple_strtol(const char *cp, char **endp, unsigned int base)
  86. {
  87. if (*cp == '-')
  88. return -simple_strtoul(cp + 1, endp, base);
  89. return simple_strtoul(cp, endp, base);
  90. }
  91. EXPORT_SYMBOL(simple_strtol);
  92. /**
  93. * simple_strtoll - convert a string to a signed long long
  94. * @cp: The start of the string
  95. * @endp: A pointer to the end of the parsed string will be placed here
  96. * @base: The number base to use
  97. */
  98. long long simple_strtoll(const char *cp, char **endp, unsigned int base)
  99. {
  100. if (*cp == '-')
  101. return -simple_strtoull(cp + 1, endp, base);
  102. return simple_strtoull(cp, endp, base);
  103. }
  104. EXPORT_SYMBOL(simple_strtoll);
  105. /**
  106. * strict_strtoul - convert a string to an unsigned long strictly
  107. * @cp: The string to be converted
  108. * @base: The number base to use
  109. * @res: The converted result value
  110. *
  111. * strict_strtoul converts a string to an unsigned long only if the
  112. * string is really an unsigned long string, any string containing
  113. * any invalid char at the tail will be rejected and -EINVAL is returned,
  114. * only a newline char at the tail is acceptible because people generally
  115. * change a module parameter in the following way:
  116. *
  117. * echo 1024 > /sys/module/e1000/parameters/copybreak
  118. *
  119. * echo will append a newline to the tail.
  120. *
  121. * It returns 0 if conversion is successful and *res is set to the converted
  122. * value, otherwise it returns -EINVAL and *res is set to 0.
  123. *
  124. * simple_strtoul just ignores the successive invalid characters and
  125. * return the converted value of prefix part of the string.
  126. */
  127. int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
  128. {
  129. char *tail;
  130. unsigned long val;
  131. *res = 0;
  132. if (!*cp)
  133. return -EINVAL;
  134. val = simple_strtoul(cp, &tail, base);
  135. if (tail == cp)
  136. return -EINVAL;
  137. if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) {
  138. *res = val;
  139. return 0;
  140. }
  141. return -EINVAL;
  142. }
  143. EXPORT_SYMBOL(strict_strtoul);
  144. /**
  145. * strict_strtol - convert a string to a long strictly
  146. * @cp: The string to be converted
  147. * @base: The number base to use
  148. * @res: The converted result value
  149. *
  150. * strict_strtol is similiar to strict_strtoul, but it allows the first
  151. * character of a string is '-'.
  152. *
  153. * It returns 0 if conversion is successful and *res is set to the converted
  154. * value, otherwise it returns -EINVAL and *res is set to 0.
  155. */
  156. int strict_strtol(const char *cp, unsigned int base, long *res)
  157. {
  158. int ret;
  159. if (*cp == '-') {
  160. ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
  161. if (!ret)
  162. *res = -(*res);
  163. } else {
  164. ret = strict_strtoul(cp, base, (unsigned long *)res);
  165. }
  166. return ret;
  167. }
  168. EXPORT_SYMBOL(strict_strtol);
  169. /**
  170. * strict_strtoull - convert a string to an unsigned long long strictly
  171. * @cp: The string to be converted
  172. * @base: The number base to use
  173. * @res: The converted result value
  174. *
  175. * strict_strtoull converts a string to an unsigned long long only if the
  176. * string is really an unsigned long long string, any string containing
  177. * any invalid char at the tail will be rejected and -EINVAL is returned,
  178. * only a newline char at the tail is acceptible because people generally
  179. * change a module parameter in the following way:
  180. *
  181. * echo 1024 > /sys/module/e1000/parameters/copybreak
  182. *
  183. * echo will append a newline to the tail of the string.
  184. *
  185. * It returns 0 if conversion is successful and *res is set to the converted
  186. * value, otherwise it returns -EINVAL and *res is set to 0.
  187. *
  188. * simple_strtoull just ignores the successive invalid characters and
  189. * return the converted value of prefix part of the string.
  190. */
  191. int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
  192. {
  193. char *tail;
  194. unsigned long long val;
  195. *res = 0;
  196. if (!*cp)
  197. return -EINVAL;
  198. val = simple_strtoull(cp, &tail, base);
  199. if (tail == cp)
  200. return -EINVAL;
  201. if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) {
  202. *res = val;
  203. return 0;
  204. }
  205. return -EINVAL;
  206. }
  207. EXPORT_SYMBOL(strict_strtoull);
  208. /**
  209. * strict_strtoll - convert a string to a long long strictly
  210. * @cp: The string to be converted
  211. * @base: The number base to use
  212. * @res: The converted result value
  213. *
  214. * strict_strtoll is similiar to strict_strtoull, but it allows the first
  215. * character of a string is '-'.
  216. *
  217. * It returns 0 if conversion is successful and *res is set to the converted
  218. * value, otherwise it returns -EINVAL and *res is set to 0.
  219. */
  220. int strict_strtoll(const char *cp, unsigned int base, long long *res)
  221. {
  222. int ret;
  223. if (*cp == '-') {
  224. ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
  225. if (!ret)
  226. *res = -(*res);
  227. } else {
  228. ret = strict_strtoull(cp, base, (unsigned long long *)res);
  229. }
  230. return ret;
  231. }
  232. EXPORT_SYMBOL(strict_strtoll);
  233. static noinline_for_stack
  234. int skip_atoi(const char **s)
  235. {
  236. int i = 0;
  237. while (isdigit(**s))
  238. i = i*10 + *((*s)++) - '0';
  239. return i;
  240. }
  241. /* Decimal conversion is by far the most typical, and is used
  242. * for /proc and /sys data. This directly impacts e.g. top performance
  243. * with many processes running. We optimize it for speed
  244. * using code from
  245. * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
  246. * (with permission from the author, Douglas W. Jones). */
  247. /* Formats correctly any integer in [0,99999].
  248. * Outputs from one to five digits depending on input.
  249. * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
  250. static noinline_for_stack
  251. char *put_dec_trunc(char *buf, unsigned q)
  252. {
  253. unsigned d3, d2, d1, d0;
  254. d1 = (q>>4) & 0xf;
  255. d2 = (q>>8) & 0xf;
  256. d3 = (q>>12);
  257. d0 = 6*(d3 + d2 + d1) + (q & 0xf);
  258. q = (d0 * 0xcd) >> 11;
  259. d0 = d0 - 10*q;
  260. *buf++ = d0 + '0'; /* least significant digit */
  261. d1 = q + 9*d3 + 5*d2 + d1;
  262. if (d1 != 0) {
  263. q = (d1 * 0xcd) >> 11;
  264. d1 = d1 - 10*q;
  265. *buf++ = d1 + '0'; /* next digit */
  266. d2 = q + 2*d2;
  267. if ((d2 != 0) || (d3 != 0)) {
  268. q = (d2 * 0xd) >> 7;
  269. d2 = d2 - 10*q;
  270. *buf++ = d2 + '0'; /* next digit */
  271. d3 = q + 4*d3;
  272. if (d3 != 0) {
  273. q = (d3 * 0xcd) >> 11;
  274. d3 = d3 - 10*q;
  275. *buf++ = d3 + '0'; /* next digit */
  276. if (q != 0)
  277. *buf++ = q + '0'; /* most sign. digit */
  278. }
  279. }
  280. }
  281. return buf;
  282. }
  283. /* Same with if's removed. Always emits five digits */
  284. static noinline_for_stack
  285. char *put_dec_full(char *buf, unsigned q)
  286. {
  287. /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
  288. /* but anyway, gcc produces better code with full-sized ints */
  289. unsigned d3, d2, d1, d0;
  290. d1 = (q>>4) & 0xf;
  291. d2 = (q>>8) & 0xf;
  292. d3 = (q>>12);
  293. /*
  294. * Possible ways to approx. divide by 10
  295. * gcc -O2 replaces multiply with shifts and adds
  296. * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
  297. * (x * 0x67) >> 10: 1100111
  298. * (x * 0x34) >> 9: 110100 - same
  299. * (x * 0x1a) >> 8: 11010 - same
  300. * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
  301. */
  302. d0 = 6*(d3 + d2 + d1) + (q & 0xf);
  303. q = (d0 * 0xcd) >> 11;
  304. d0 = d0 - 10*q;
  305. *buf++ = d0 + '0';
  306. d1 = q + 9*d3 + 5*d2 + d1;
  307. q = (d1 * 0xcd) >> 11;
  308. d1 = d1 - 10*q;
  309. *buf++ = d1 + '0';
  310. d2 = q + 2*d2;
  311. q = (d2 * 0xd) >> 7;
  312. d2 = d2 - 10*q;
  313. *buf++ = d2 + '0';
  314. d3 = q + 4*d3;
  315. q = (d3 * 0xcd) >> 11; /* - shorter code */
  316. /* q = (d3 * 0x67) >> 10; - would also work */
  317. d3 = d3 - 10*q;
  318. *buf++ = d3 + '0';
  319. *buf++ = q + '0';
  320. return buf;
  321. }
  322. /* No inlining helps gcc to use registers better */
  323. static noinline_for_stack
  324. char *put_dec(char *buf, unsigned long long num)
  325. {
  326. while (1) {
  327. unsigned rem;
  328. if (num < 100000)
  329. return put_dec_trunc(buf, num);
  330. rem = do_div(num, 100000);
  331. buf = put_dec_full(buf, rem);
  332. }
  333. }
  334. #define ZEROPAD 1 /* pad with zero */
  335. #define SIGN 2 /* unsigned/signed long */
  336. #define PLUS 4 /* show plus */
  337. #define SPACE 8 /* space if plus */
  338. #define LEFT 16 /* left justified */
  339. #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
  340. #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
  341. enum format_type {
  342. FORMAT_TYPE_NONE, /* Just a string part */
  343. FORMAT_TYPE_WIDTH,
  344. FORMAT_TYPE_PRECISION,
  345. FORMAT_TYPE_CHAR,
  346. FORMAT_TYPE_STR,
  347. FORMAT_TYPE_PTR,
  348. FORMAT_TYPE_PERCENT_CHAR,
  349. FORMAT_TYPE_INVALID,
  350. FORMAT_TYPE_LONG_LONG,
  351. FORMAT_TYPE_ULONG,
  352. FORMAT_TYPE_LONG,
  353. FORMAT_TYPE_UBYTE,
  354. FORMAT_TYPE_BYTE,
  355. FORMAT_TYPE_USHORT,
  356. FORMAT_TYPE_SHORT,
  357. FORMAT_TYPE_UINT,
  358. FORMAT_TYPE_INT,
  359. FORMAT_TYPE_NRCHARS,
  360. FORMAT_TYPE_SIZE_T,
  361. FORMAT_TYPE_PTRDIFF
  362. };
  363. struct printf_spec {
  364. u8 type; /* format_type enum */
  365. u8 flags; /* flags to number() */
  366. u8 base; /* number base, 8, 10 or 16 only */
  367. u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */
  368. s16 field_width; /* width of output field */
  369. s16 precision; /* # of digits/chars */
  370. };
  371. static noinline_for_stack
  372. char *number(char *buf, char *end, unsigned long long num,
  373. struct printf_spec spec)
  374. {
  375. /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
  376. static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
  377. char tmp[66];
  378. char sign;
  379. char locase;
  380. int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
  381. int i;
  382. /* locase = 0 or 0x20. ORing digits or letters with 'locase'
  383. * produces same digits or (maybe lowercased) letters */
  384. locase = (spec.flags & SMALL);
  385. if (spec.flags & LEFT)
  386. spec.flags &= ~ZEROPAD;
  387. sign = 0;
  388. if (spec.flags & SIGN) {
  389. if ((signed long long)num < 0) {
  390. sign = '-';
  391. num = -(signed long long)num;
  392. spec.field_width--;
  393. } else if (spec.flags & PLUS) {
  394. sign = '+';
  395. spec.field_width--;
  396. } else if (spec.flags & SPACE) {
  397. sign = ' ';
  398. spec.field_width--;
  399. }
  400. }
  401. if (need_pfx) {
  402. spec.field_width--;
  403. if (spec.base == 16)
  404. spec.field_width--;
  405. }
  406. /* generate full string in tmp[], in reverse order */
  407. i = 0;
  408. if (num == 0)
  409. tmp[i++] = '0';
  410. /* Generic code, for any base:
  411. else do {
  412. tmp[i++] = (digits[do_div(num,base)] | locase);
  413. } while (num != 0);
  414. */
  415. else if (spec.base != 10) { /* 8 or 16 */
  416. int mask = spec.base - 1;
  417. int shift = 3;
  418. if (spec.base == 16)
  419. shift = 4;
  420. do {
  421. tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
  422. num >>= shift;
  423. } while (num);
  424. } else { /* base 10 */
  425. i = put_dec(tmp, num) - tmp;
  426. }
  427. /* printing 100 using %2d gives "100", not "00" */
  428. if (i > spec.precision)
  429. spec.precision = i;
  430. /* leading space padding */
  431. spec.field_width -= spec.precision;
  432. if (!(spec.flags & (ZEROPAD+LEFT))) {
  433. while (--spec.field_width >= 0) {
  434. if (buf < end)
  435. *buf = ' ';
  436. ++buf;
  437. }
  438. }
  439. /* sign */
  440. if (sign) {
  441. if (buf < end)
  442. *buf = sign;
  443. ++buf;
  444. }
  445. /* "0x" / "0" prefix */
  446. if (need_pfx) {
  447. if (buf < end)
  448. *buf = '0';
  449. ++buf;
  450. if (spec.base == 16) {
  451. if (buf < end)
  452. *buf = ('X' | locase);
  453. ++buf;
  454. }
  455. }
  456. /* zero or space padding */
  457. if (!(spec.flags & LEFT)) {
  458. char c = (spec.flags & ZEROPAD) ? '0' : ' ';
  459. while (--spec.field_width >= 0) {
  460. if (buf < end)
  461. *buf = c;
  462. ++buf;
  463. }
  464. }
  465. /* hmm even more zero padding? */
  466. while (i <= --spec.precision) {
  467. if (buf < end)
  468. *buf = '0';
  469. ++buf;
  470. }
  471. /* actual digits of result */
  472. while (--i >= 0) {
  473. if (buf < end)
  474. *buf = tmp[i];
  475. ++buf;
  476. }
  477. /* trailing space padding */
  478. while (--spec.field_width >= 0) {
  479. if (buf < end)
  480. *buf = ' ';
  481. ++buf;
  482. }
  483. return buf;
  484. }
  485. static noinline_for_stack
  486. char *string(char *buf, char *end, const char *s, struct printf_spec spec)
  487. {
  488. int len, i;
  489. if ((unsigned long)s < PAGE_SIZE)
  490. s = "(null)";
  491. len = strnlen(s, spec.precision);
  492. if (!(spec.flags & LEFT)) {
  493. while (len < spec.field_width--) {
  494. if (buf < end)
  495. *buf = ' ';
  496. ++buf;
  497. }
  498. }
  499. for (i = 0; i < len; ++i) {
  500. if (buf < end)
  501. *buf = *s;
  502. ++buf; ++s;
  503. }
  504. while (len < spec.field_width--) {
  505. if (buf < end)
  506. *buf = ' ';
  507. ++buf;
  508. }
  509. return buf;
  510. }
  511. static noinline_for_stack
  512. char *symbol_string(char *buf, char *end, void *ptr,
  513. struct printf_spec spec, char ext)
  514. {
  515. unsigned long value = (unsigned long) ptr;
  516. #ifdef CONFIG_KALLSYMS
  517. char sym[KSYM_SYMBOL_LEN];
  518. if (ext != 'f' && ext != 's')
  519. sprint_symbol(sym, value);
  520. else
  521. kallsyms_lookup(value, NULL, NULL, NULL, sym);
  522. return string(buf, end, sym, spec);
  523. #else
  524. spec.field_width = 2 * sizeof(void *);
  525. spec.flags |= SPECIAL | SMALL | ZEROPAD;
  526. spec.base = 16;
  527. return number(buf, end, value, spec);
  528. #endif
  529. }
  530. static noinline_for_stack
  531. char *resource_string(char *buf, char *end, struct resource *res,
  532. struct printf_spec spec, const char *fmt)
  533. {
  534. #ifndef IO_RSRC_PRINTK_SIZE
  535. #define IO_RSRC_PRINTK_SIZE 6
  536. #endif
  537. #ifndef MEM_RSRC_PRINTK_SIZE
  538. #define MEM_RSRC_PRINTK_SIZE 10
  539. #endif
  540. static const struct printf_spec io_spec = {
  541. .base = 16,
  542. .field_width = IO_RSRC_PRINTK_SIZE,
  543. .precision = -1,
  544. .flags = SPECIAL | SMALL | ZEROPAD,
  545. };
  546. static const struct printf_spec mem_spec = {
  547. .base = 16,
  548. .field_width = MEM_RSRC_PRINTK_SIZE,
  549. .precision = -1,
  550. .flags = SPECIAL | SMALL | ZEROPAD,
  551. };
  552. static const struct printf_spec bus_spec = {
  553. .base = 16,
  554. .field_width = 2,
  555. .precision = -1,
  556. .flags = SMALL | ZEROPAD,
  557. };
  558. static const struct printf_spec dec_spec = {
  559. .base = 10,
  560. .precision = -1,
  561. .flags = 0,
  562. };
  563. static const struct printf_spec str_spec = {
  564. .field_width = -1,
  565. .precision = 10,
  566. .flags = LEFT,
  567. };
  568. static const struct printf_spec flag_spec = {
  569. .base = 16,
  570. .precision = -1,
  571. .flags = SPECIAL | SMALL,
  572. };
  573. /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
  574. * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
  575. #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
  576. #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
  577. #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
  578. #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
  579. char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
  580. 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
  581. char *p = sym, *pend = sym + sizeof(sym);
  582. int decode = (fmt[0] == 'R') ? 1 : 0;
  583. const struct printf_spec *specp;
  584. *p++ = '[';
  585. if (res->flags & IORESOURCE_IO) {
  586. p = string(p, pend, "io ", str_spec);
  587. specp = &io_spec;
  588. } else if (res->flags & IORESOURCE_MEM) {
  589. p = string(p, pend, "mem ", str_spec);
  590. specp = &mem_spec;
  591. } else if (res->flags & IORESOURCE_IRQ) {
  592. p = string(p, pend, "irq ", str_spec);
  593. specp = &dec_spec;
  594. } else if (res->flags & IORESOURCE_DMA) {
  595. p = string(p, pend, "dma ", str_spec);
  596. specp = &dec_spec;
  597. } else if (res->flags & IORESOURCE_BUS) {
  598. p = string(p, pend, "bus ", str_spec);
  599. specp = &bus_spec;
  600. } else {
  601. p = string(p, pend, "??? ", str_spec);
  602. specp = &mem_spec;
  603. decode = 0;
  604. }
  605. p = number(p, pend, res->start, *specp);
  606. if (res->start != res->end) {
  607. *p++ = '-';
  608. p = number(p, pend, res->end, *specp);
  609. }
  610. if (decode) {
  611. if (res->flags & IORESOURCE_MEM_64)
  612. p = string(p, pend, " 64bit", str_spec);
  613. if (res->flags & IORESOURCE_PREFETCH)
  614. p = string(p, pend, " pref", str_spec);
  615. if (res->flags & IORESOURCE_WINDOW)
  616. p = string(p, pend, " window", str_spec);
  617. if (res->flags & IORESOURCE_DISABLED)
  618. p = string(p, pend, " disabled", str_spec);
  619. } else {
  620. p = string(p, pend, " flags ", str_spec);
  621. p = number(p, pend, res->flags, flag_spec);
  622. }
  623. *p++ = ']';
  624. *p = '\0';
  625. return string(buf, end, sym, spec);
  626. }
  627. static noinline_for_stack
  628. char *mac_address_string(char *buf, char *end, u8 *addr,
  629. struct printf_spec spec, const char *fmt)
  630. {
  631. char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
  632. char *p = mac_addr;
  633. int i;
  634. char separator;
  635. if (fmt[1] == 'F') { /* FDDI canonical format */
  636. separator = '-';
  637. } else {
  638. separator = ':';
  639. }
  640. for (i = 0; i < 6; i++) {
  641. p = pack_hex_byte(p, addr[i]);
  642. if (fmt[0] == 'M' && i != 5)
  643. *p++ = separator;
  644. }
  645. *p = '\0';
  646. return string(buf, end, mac_addr, spec);
  647. }
  648. static noinline_for_stack
  649. char *ip4_string(char *p, const u8 *addr, const char *fmt)
  650. {
  651. int i;
  652. bool leading_zeros = (fmt[0] == 'i');
  653. int index;
  654. int step;
  655. switch (fmt[2]) {
  656. case 'h':
  657. #ifdef __BIG_ENDIAN
  658. index = 0;
  659. step = 1;
  660. #else
  661. index = 3;
  662. step = -1;
  663. #endif
  664. break;
  665. case 'l':
  666. index = 3;
  667. step = -1;
  668. break;
  669. case 'n':
  670. case 'b':
  671. default:
  672. index = 0;
  673. step = 1;
  674. break;
  675. }
  676. for (i = 0; i < 4; i++) {
  677. char temp[3]; /* hold each IP quad in reverse order */
  678. int digits = put_dec_trunc(temp, addr[index]) - temp;
  679. if (leading_zeros) {
  680. if (digits < 3)
  681. *p++ = '0';
  682. if (digits < 2)
  683. *p++ = '0';
  684. }
  685. /* reverse the digits in the quad */
  686. while (digits--)
  687. *p++ = temp[digits];
  688. if (i < 3)
  689. *p++ = '.';
  690. index += step;
  691. }
  692. *p = '\0';
  693. return p;
  694. }
  695. static noinline_for_stack
  696. char *ip6_compressed_string(char *p, const char *addr)
  697. {
  698. int i, j, range;
  699. unsigned char zerolength[8];
  700. int longest = 1;
  701. int colonpos = -1;
  702. u16 word;
  703. u8 hi, lo;
  704. bool needcolon = false;
  705. bool useIPv4;
  706. struct in6_addr in6;
  707. memcpy(&in6, addr, sizeof(struct in6_addr));
  708. useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
  709. memset(zerolength, 0, sizeof(zerolength));
  710. if (useIPv4)
  711. range = 6;
  712. else
  713. range = 8;
  714. /* find position of longest 0 run */
  715. for (i = 0; i < range; i++) {
  716. for (j = i; j < range; j++) {
  717. if (in6.s6_addr16[j] != 0)
  718. break;
  719. zerolength[i]++;
  720. }
  721. }
  722. for (i = 0; i < range; i++) {
  723. if (zerolength[i] > longest) {
  724. longest = zerolength[i];
  725. colonpos = i;
  726. }
  727. }
  728. /* emit address */
  729. for (i = 0; i < range; i++) {
  730. if (i == colonpos) {
  731. if (needcolon || i == 0)
  732. *p++ = ':';
  733. *p++ = ':';
  734. needcolon = false;
  735. i += longest - 1;
  736. continue;
  737. }
  738. if (needcolon) {
  739. *p++ = ':';
  740. needcolon = false;
  741. }
  742. /* hex u16 without leading 0s */
  743. word = ntohs(in6.s6_addr16[i]);
  744. hi = word >> 8;
  745. lo = word & 0xff;
  746. if (hi) {
  747. if (hi > 0x0f)
  748. p = pack_hex_byte(p, hi);
  749. else
  750. *p++ = hex_asc_lo(hi);
  751. p = pack_hex_byte(p, lo);
  752. }
  753. else if (lo > 0x0f)
  754. p = pack_hex_byte(p, lo);
  755. else
  756. *p++ = hex_asc_lo(lo);
  757. needcolon = true;
  758. }
  759. if (useIPv4) {
  760. if (needcolon)
  761. *p++ = ':';
  762. p = ip4_string(p, &in6.s6_addr[12], "I4");
  763. }
  764. *p = '\0';
  765. return p;
  766. }
  767. static noinline_for_stack
  768. char *ip6_string(char *p, const char *addr, const char *fmt)
  769. {
  770. int i;
  771. for (i = 0; i < 8; i++) {
  772. p = pack_hex_byte(p, *addr++);
  773. p = pack_hex_byte(p, *addr++);
  774. if (fmt[0] == 'I' && i != 7)
  775. *p++ = ':';
  776. }
  777. *p = '\0';
  778. return p;
  779. }
  780. static noinline_for_stack
  781. char *ip6_addr_string(char *buf, char *end, const u8 *addr,
  782. struct printf_spec spec, const char *fmt)
  783. {
  784. char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
  785. if (fmt[0] == 'I' && fmt[2] == 'c')
  786. ip6_compressed_string(ip6_addr, addr);
  787. else
  788. ip6_string(ip6_addr, addr, fmt);
  789. return string(buf, end, ip6_addr, spec);
  790. }
  791. static noinline_for_stack
  792. char *ip4_addr_string(char *buf, char *end, const u8 *addr,
  793. struct printf_spec spec, const char *fmt)
  794. {
  795. char ip4_addr[sizeof("255.255.255.255")];
  796. ip4_string(ip4_addr, addr, fmt);
  797. return string(buf, end, ip4_addr, spec);
  798. }
  799. static noinline_for_stack
  800. char *uuid_string(char *buf, char *end, const u8 *addr,
  801. struct printf_spec spec, const char *fmt)
  802. {
  803. char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
  804. char *p = uuid;
  805. int i;
  806. static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
  807. static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
  808. const u8 *index = be;
  809. bool uc = false;
  810. switch (*(++fmt)) {
  811. case 'L':
  812. uc = true; /* fall-through */
  813. case 'l':
  814. index = le;
  815. break;
  816. case 'B':
  817. uc = true;
  818. break;
  819. }
  820. for (i = 0; i < 16; i++) {
  821. p = pack_hex_byte(p, addr[index[i]]);
  822. switch (i) {
  823. case 3:
  824. case 5:
  825. case 7:
  826. case 9:
  827. *p++ = '-';
  828. break;
  829. }
  830. }
  831. *p = 0;
  832. if (uc) {
  833. p = uuid;
  834. do {
  835. *p = toupper(*p);
  836. } while (*(++p));
  837. }
  838. return string(buf, end, uuid, spec);
  839. }
  840. /*
  841. * Show a '%p' thing. A kernel extension is that the '%p' is followed
  842. * by an extra set of alphanumeric characters that are extended format
  843. * specifiers.
  844. *
  845. * Right now we handle:
  846. *
  847. * - 'F' For symbolic function descriptor pointers with offset
  848. * - 'f' For simple symbolic function names without offset
  849. * - 'S' For symbolic direct pointers with offset
  850. * - 's' For symbolic direct pointers without offset
  851. * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
  852. * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
  853. * - 'M' For a 6-byte MAC address, it prints the address in the
  854. * usual colon-separated hex notation
  855. * - 'm' For a 6-byte MAC address, it prints the hex address without colons
  856. * - 'MF' For a 6-byte MAC FDDI address, it prints the address
  857. * with a dash-separated hex notation
  858. * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
  859. * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
  860. * IPv6 uses colon separated network-order 16 bit hex with leading 0's
  861. * - 'i' [46] for 'raw' IPv4/IPv6 addresses
  862. * IPv6 omits the colons (01020304...0f)
  863. * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
  864. * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
  865. * - 'I6c' for IPv6 addresses printed as specified by
  866. * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
  867. * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
  868. * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
  869. * Options for %pU are:
  870. * b big endian lower case hex (default)
  871. * B big endian UPPER case hex
  872. * l little endian lower case hex
  873. * L little endian UPPER case hex
  874. * big endian output byte order is:
  875. * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
  876. * little endian output byte order is:
  877. * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
  878. * - 'V' For a struct va_format which contains a format string * and va_list *,
  879. * call vsnprintf(->format, *->va_list).
  880. * Implements a "recursive vsnprintf".
  881. * Do not use this feature without some mechanism to verify the
  882. * correctness of the format string and va_list arguments.
  883. *
  884. * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
  885. * function pointers are really function descriptors, which contain a
  886. * pointer to the real address.
  887. */
  888. static noinline_for_stack
  889. char *pointer(const char *fmt, char *buf, char *end, void *ptr,
  890. struct printf_spec spec)
  891. {
  892. if (!ptr)
  893. return string(buf, end, "(null)", spec);
  894. switch (*fmt) {
  895. case 'F':
  896. case 'f':
  897. ptr = dereference_function_descriptor(ptr);
  898. /* Fallthrough */
  899. case 'S':
  900. case 's':
  901. return symbol_string(buf, end, ptr, spec, *fmt);
  902. case 'R':
  903. case 'r':
  904. return resource_string(buf, end, ptr, spec, fmt);
  905. case 'M': /* Colon separated: 00:01:02:03:04:05 */
  906. case 'm': /* Contiguous: 000102030405 */
  907. /* [mM]F (FDDI, bit reversed) */
  908. return mac_address_string(buf, end, ptr, spec, fmt);
  909. case 'I': /* Formatted IP supported
  910. * 4: 1.2.3.4
  911. * 6: 0001:0203:...:0708
  912. * 6c: 1::708 or 1::1.2.3.4
  913. */
  914. case 'i': /* Contiguous:
  915. * 4: 001.002.003.004
  916. * 6: 000102...0f
  917. */
  918. switch (fmt[1]) {
  919. case '6':
  920. return ip6_addr_string(buf, end, ptr, spec, fmt);
  921. case '4':
  922. return ip4_addr_string(buf, end, ptr, spec, fmt);
  923. }
  924. break;
  925. case 'U':
  926. return uuid_string(buf, end, ptr, spec, fmt);
  927. case 'V':
  928. return buf + vsnprintf(buf, end - buf,
  929. ((struct va_format *)ptr)->fmt,
  930. *(((struct va_format *)ptr)->va));
  931. }
  932. spec.flags |= SMALL;
  933. if (spec.field_width == -1) {
  934. spec.field_width = 2*sizeof(void *);
  935. spec.flags |= ZEROPAD;
  936. }
  937. spec.base = 16;
  938. return number(buf, end, (unsigned long) ptr, spec);
  939. }
  940. /*
  941. * Helper function to decode printf style format.
  942. * Each call decode a token from the format and return the
  943. * number of characters read (or likely the delta where it wants
  944. * to go on the next call).
  945. * The decoded token is returned through the parameters
  946. *
  947. * 'h', 'l', or 'L' for integer fields
  948. * 'z' support added 23/7/1999 S.H.
  949. * 'z' changed to 'Z' --davidm 1/25/99
  950. * 't' added for ptrdiff_t
  951. *
  952. * @fmt: the format string
  953. * @type of the token returned
  954. * @flags: various flags such as +, -, # tokens..
  955. * @field_width: overwritten width
  956. * @base: base of the number (octal, hex, ...)
  957. * @precision: precision of a number
  958. * @qualifier: qualifier of a number (long, size_t, ...)
  959. */
  960. static noinline_for_stack
  961. int format_decode(const char *fmt, struct printf_spec *spec)
  962. {
  963. const char *start = fmt;
  964. /* we finished early by reading the field width */
  965. if (spec->type == FORMAT_TYPE_WIDTH) {
  966. if (spec->field_width < 0) {
  967. spec->field_width = -spec->field_width;
  968. spec->flags |= LEFT;
  969. }
  970. spec->type = FORMAT_TYPE_NONE;
  971. goto precision;
  972. }
  973. /* we finished early by reading the precision */
  974. if (spec->type == FORMAT_TYPE_PRECISION) {
  975. if (spec->precision < 0)
  976. spec->precision = 0;
  977. spec->type = FORMAT_TYPE_NONE;
  978. goto qualifier;
  979. }
  980. /* By default */
  981. spec->type = FORMAT_TYPE_NONE;
  982. for (; *fmt ; ++fmt) {
  983. if (*fmt == '%')
  984. break;
  985. }
  986. /* Return the current non-format string */
  987. if (fmt != start || !*fmt)
  988. return fmt - start;
  989. /* Process flags */
  990. spec->flags = 0;
  991. while (1) { /* this also skips first '%' */
  992. bool found = true;
  993. ++fmt;
  994. switch (*fmt) {
  995. case '-': spec->flags |= LEFT; break;
  996. case '+': spec->flags |= PLUS; break;
  997. case ' ': spec->flags |= SPACE; break;
  998. case '#': spec->flags |= SPECIAL; break;
  999. case '0': spec->flags |= ZEROPAD; break;
  1000. default: found = false;
  1001. }
  1002. if (!found)
  1003. break;
  1004. }
  1005. /* get field width */
  1006. spec->field_width = -1;
  1007. if (isdigit(*fmt))
  1008. spec->field_width = skip_atoi(&fmt);
  1009. else if (*fmt == '*') {
  1010. /* it's the next argument */
  1011. spec->type = FORMAT_TYPE_WIDTH;
  1012. return ++fmt - start;
  1013. }
  1014. precision:
  1015. /* get the precision */
  1016. spec->precision = -1;
  1017. if (*fmt == '.') {
  1018. ++fmt;
  1019. if (isdigit(*fmt)) {
  1020. spec->precision = skip_atoi(&fmt);
  1021. if (spec->precision < 0)
  1022. spec->precision = 0;
  1023. } else if (*fmt == '*') {
  1024. /* it's the next argument */
  1025. spec->type = FORMAT_TYPE_PRECISION;
  1026. return ++fmt - start;
  1027. }
  1028. }
  1029. qualifier:
  1030. /* get the conversion qualifier */
  1031. spec->qualifier = -1;
  1032. if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
  1033. TOLOWER(*fmt) == 'z' || *fmt == 't') {
  1034. spec->qualifier = *fmt++;
  1035. if (unlikely(spec->qualifier == *fmt)) {
  1036. if (spec->qualifier == 'l') {
  1037. spec->qualifier = 'L';
  1038. ++fmt;
  1039. } else if (spec->qualifier == 'h') {
  1040. spec->qualifier = 'H';
  1041. ++fmt;
  1042. }
  1043. }
  1044. }
  1045. /* default base */
  1046. spec->base = 10;
  1047. switch (*fmt) {
  1048. case 'c':
  1049. spec->type = FORMAT_TYPE_CHAR;
  1050. return ++fmt - start;
  1051. case 's':
  1052. spec->type = FORMAT_TYPE_STR;
  1053. return ++fmt - start;
  1054. case 'p':
  1055. spec->type = FORMAT_TYPE_PTR;
  1056. return fmt - start;
  1057. /* skip alnum */
  1058. case 'n':
  1059. spec->type = FORMAT_TYPE_NRCHARS;
  1060. return ++fmt - start;
  1061. case '%':
  1062. spec->type = FORMAT_TYPE_PERCENT_CHAR;
  1063. return ++fmt - start;
  1064. /* integer number formats - set up the flags and "break" */
  1065. case 'o':
  1066. spec->base = 8;
  1067. break;
  1068. case 'x':
  1069. spec->flags |= SMALL;
  1070. case 'X':
  1071. spec->base = 16;
  1072. break;
  1073. case 'd':
  1074. case 'i':
  1075. spec->flags |= SIGN;
  1076. case 'u':
  1077. break;
  1078. default:
  1079. spec->type = FORMAT_TYPE_INVALID;
  1080. return fmt - start;
  1081. }
  1082. if (spec->qualifier == 'L')
  1083. spec->type = FORMAT_TYPE_LONG_LONG;
  1084. else if (spec->qualifier == 'l') {
  1085. if (spec->flags & SIGN)
  1086. spec->type = FORMAT_TYPE_LONG;
  1087. else
  1088. spec->type = FORMAT_TYPE_ULONG;
  1089. } else if (TOLOWER(spec->qualifier) == 'z') {
  1090. spec->type = FORMAT_TYPE_SIZE_T;
  1091. } else if (spec->qualifier == 't') {
  1092. spec->type = FORMAT_TYPE_PTRDIFF;
  1093. } else if (spec->qualifier == 'H') {
  1094. if (spec->flags & SIGN)
  1095. spec->type = FORMAT_TYPE_BYTE;
  1096. else
  1097. spec->type = FORMAT_TYPE_UBYTE;
  1098. } else if (spec->qualifier == 'h') {
  1099. if (spec->flags & SIGN)
  1100. spec->type = FORMAT_TYPE_SHORT;
  1101. else
  1102. spec->type = FORMAT_TYPE_USHORT;
  1103. } else {
  1104. if (spec->flags & SIGN)
  1105. spec->type = FORMAT_TYPE_INT;
  1106. else
  1107. spec->type = FORMAT_TYPE_UINT;
  1108. }
  1109. return ++fmt - start;
  1110. }
  1111. /**
  1112. * vsnprintf - Format a string and place it in a buffer
  1113. * @buf: The buffer to place the result into
  1114. * @size: The size of the buffer, including the trailing null space
  1115. * @fmt: The format string to use
  1116. * @args: Arguments for the format string
  1117. *
  1118. * This function follows C99 vsnprintf, but has some extensions:
  1119. * %pS output the name of a text symbol with offset
  1120. * %ps output the name of a text symbol without offset
  1121. * %pF output the name of a function pointer with its offset
  1122. * %pf output the name of a function pointer without its offset
  1123. * %pR output the address range in a struct resource with decoded flags
  1124. * %pr output the address range in a struct resource with raw flags
  1125. * %pM output a 6-byte MAC address with colons
  1126. * %pm output a 6-byte MAC address without colons
  1127. * %pI4 print an IPv4 address without leading zeros
  1128. * %pi4 print an IPv4 address with leading zeros
  1129. * %pI6 print an IPv6 address with colons
  1130. * %pi6 print an IPv6 address without colons
  1131. * %pI6c print an IPv6 address as specified by
  1132. * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
  1133. * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
  1134. * case.
  1135. * %n is ignored
  1136. *
  1137. * The return value is the number of characters which would
  1138. * be generated for the given input, excluding the trailing
  1139. * '\0', as per ISO C99. If you want to have the exact
  1140. * number of characters written into @buf as return value
  1141. * (not including the trailing '\0'), use vscnprintf(). If the
  1142. * return is greater than or equal to @size, the resulting
  1143. * string is truncated.
  1144. *
  1145. * Call this function if you are already dealing with a va_list.
  1146. * You probably want snprintf() instead.
  1147. */
  1148. int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
  1149. {
  1150. unsigned long long num;
  1151. char *str, *end;
  1152. struct printf_spec spec = {0};
  1153. /* Reject out-of-range values early. Large positive sizes are
  1154. used for unknown buffer sizes. */
  1155. if (WARN_ON_ONCE((int) size < 0))
  1156. return 0;
  1157. str = buf;
  1158. end = buf + size;
  1159. /* Make sure end is always >= buf */
  1160. if (end < buf) {
  1161. end = ((void *)-1);
  1162. size = end - buf;
  1163. }
  1164. while (*fmt) {
  1165. const char *old_fmt = fmt;
  1166. int read = format_decode(fmt, &spec);
  1167. fmt += read;
  1168. switch (spec.type) {
  1169. case FORMAT_TYPE_NONE: {
  1170. int copy = read;
  1171. if (str < end) {
  1172. if (copy > end - str)
  1173. copy = end - str;
  1174. memcpy(str, old_fmt, copy);
  1175. }
  1176. str += read;
  1177. break;
  1178. }
  1179. case FORMAT_TYPE_WIDTH:
  1180. spec.field_width = va_arg(args, int);
  1181. break;
  1182. case FORMAT_TYPE_PRECISION:
  1183. spec.precision = va_arg(args, int);
  1184. break;
  1185. case FORMAT_TYPE_CHAR: {
  1186. char c;
  1187. if (!(spec.flags & LEFT)) {
  1188. while (--spec.field_width > 0) {
  1189. if (str < end)
  1190. *str = ' ';
  1191. ++str;
  1192. }
  1193. }
  1194. c = (unsigned char) va_arg(args, int);
  1195. if (str < end)
  1196. *str = c;
  1197. ++str;
  1198. while (--spec.field_width > 0) {
  1199. if (str < end)
  1200. *str = ' ';
  1201. ++str;
  1202. }
  1203. break;
  1204. }
  1205. case FORMAT_TYPE_STR:
  1206. str = string(str, end, va_arg(args, char *), spec);
  1207. break;
  1208. case FORMAT_TYPE_PTR:
  1209. str = pointer(fmt+1, str, end, va_arg(args, void *),
  1210. spec);
  1211. while (isalnum(*fmt))
  1212. fmt++;
  1213. break;
  1214. case FORMAT_TYPE_PERCENT_CHAR:
  1215. if (str < end)
  1216. *str = '%';
  1217. ++str;
  1218. break;
  1219. case FORMAT_TYPE_INVALID:
  1220. if (str < end)
  1221. *str = '%';
  1222. ++str;
  1223. break;
  1224. case FORMAT_TYPE_NRCHARS: {
  1225. u8 qualifier = spec.qualifier;
  1226. if (qualifier == 'l') {
  1227. long *ip = va_arg(args, long *);
  1228. *ip = (str - buf);
  1229. } else if (TOLOWER(qualifier) == 'z') {
  1230. size_t *ip = va_arg(args, size_t *);
  1231. *ip = (str - buf);
  1232. } else {
  1233. int *ip = va_arg(args, int *);
  1234. *ip = (str - buf);
  1235. }
  1236. break;
  1237. }
  1238. default:
  1239. switch (spec.type) {
  1240. case FORMAT_TYPE_LONG_LONG:
  1241. num = va_arg(args, long long);
  1242. break;
  1243. case FORMAT_TYPE_ULONG:
  1244. num = va_arg(args, unsigned long);
  1245. break;
  1246. case FORMAT_TYPE_LONG:
  1247. num = va_arg(args, long);
  1248. break;
  1249. case FORMAT_TYPE_SIZE_T:
  1250. num = va_arg(args, size_t);
  1251. break;
  1252. case FORMAT_TYPE_PTRDIFF:
  1253. num = va_arg(args, ptrdiff_t);
  1254. break;
  1255. case FORMAT_TYPE_UBYTE:
  1256. num = (unsigned char) va_arg(args, int);
  1257. break;
  1258. case FORMAT_TYPE_BYTE:
  1259. num = (signed char) va_arg(args, int);
  1260. break;
  1261. case FORMAT_TYPE_USHORT:
  1262. num = (unsigned short) va_arg(args, int);
  1263. break;
  1264. case FORMAT_TYPE_SHORT:
  1265. num = (short) va_arg(args, int);
  1266. break;
  1267. case FORMAT_TYPE_INT:
  1268. num = (int) va_arg(args, int);
  1269. break;
  1270. default:
  1271. num = va_arg(args, unsigned int);
  1272. }
  1273. str = number(str, end, num, spec);
  1274. }
  1275. }
  1276. if (size > 0) {
  1277. if (str < end)
  1278. *str = '\0';
  1279. else
  1280. end[-1] = '\0';
  1281. }
  1282. /* the trailing null byte doesn't count towards the total */
  1283. return str-buf;
  1284. }
  1285. EXPORT_SYMBOL(vsnprintf);
  1286. /**
  1287. * vscnprintf - Format a string and place it in a buffer
  1288. * @buf: The buffer to place the result into
  1289. * @size: The size of the buffer, including the trailing null space
  1290. * @fmt: The format string to use
  1291. * @args: Arguments for the format string
  1292. *
  1293. * The return value is the number of characters which have been written into
  1294. * the @buf not including the trailing '\0'. If @size is <= 0 the function
  1295. * returns 0.
  1296. *
  1297. * Call this function if you are already dealing with a va_list.
  1298. * You probably want scnprintf() instead.
  1299. *
  1300. * See the vsnprintf() documentation for format string extensions over C99.
  1301. */
  1302. int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
  1303. {
  1304. int i;
  1305. i = vsnprintf(buf, size, fmt, args);
  1306. return (i >= size) ? (size - 1) : i;
  1307. }
  1308. EXPORT_SYMBOL(vscnprintf);
  1309. /**
  1310. * snprintf - Format a string and place it in a buffer
  1311. * @buf: The buffer to place the result into
  1312. * @size: The size of the buffer, including the trailing null space
  1313. * @fmt: The format string to use
  1314. * @...: Arguments for the format string
  1315. *
  1316. * The return value is the number of characters which would be
  1317. * generated for the given input, excluding the trailing null,
  1318. * as per ISO C99. If the return is greater than or equal to
  1319. * @size, the resulting string is truncated.
  1320. *
  1321. * See the vsnprintf() documentation for format string extensions over C99.
  1322. */
  1323. int snprintf(char *buf, size_t size, const char *fmt, ...)
  1324. {
  1325. va_list args;
  1326. int i;
  1327. va_start(args, fmt);
  1328. i = vsnprintf(buf, size, fmt, args);
  1329. va_end(args);
  1330. return i;
  1331. }
  1332. EXPORT_SYMBOL(snprintf);
  1333. /**
  1334. * scnprintf - Format a string and place it in a buffer
  1335. * @buf: The buffer to place the result into
  1336. * @size: The size of the buffer, including the trailing null space
  1337. * @fmt: The format string to use
  1338. * @...: Arguments for the format string
  1339. *
  1340. * The return value is the number of characters written into @buf not including
  1341. * the trailing '\0'. If @size is <= 0 the function returns 0.
  1342. */
  1343. int scnprintf(char *buf, size_t size, const char *fmt, ...)
  1344. {
  1345. va_list args;
  1346. int i;
  1347. va_start(args, fmt);
  1348. i = vsnprintf(buf, size, fmt, args);
  1349. va_end(args);
  1350. return (i >= size) ? (size - 1) : i;
  1351. }
  1352. EXPORT_SYMBOL(scnprintf);
  1353. /**
  1354. * vsprintf - Format a string and place it in a buffer
  1355. * @buf: The buffer to place the result into
  1356. * @fmt: The format string to use
  1357. * @args: Arguments for the format string
  1358. *
  1359. * The function returns the number of characters written
  1360. * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
  1361. * buffer overflows.
  1362. *
  1363. * Call this function if you are already dealing with a va_list.
  1364. * You probably want sprintf() instead.
  1365. *
  1366. * See the vsnprintf() documentation for format string extensions over C99.
  1367. */
  1368. int vsprintf(char *buf, const char *fmt, va_list args)
  1369. {
  1370. return vsnprintf(buf, INT_MAX, fmt, args);
  1371. }
  1372. EXPORT_SYMBOL(vsprintf);
  1373. /**
  1374. * sprintf - Format a string and place it in a buffer
  1375. * @buf: The buffer to place the result into
  1376. * @fmt: The format string to use
  1377. * @...: Arguments for the format string
  1378. *
  1379. * The function returns the number of characters written
  1380. * into @buf. Use snprintf() or scnprintf() in order to avoid
  1381. * buffer overflows.
  1382. *
  1383. * See the vsnprintf() documentation for format string extensions over C99.
  1384. */
  1385. int sprintf(char *buf, const char *fmt, ...)
  1386. {
  1387. va_list args;
  1388. int i;
  1389. va_start(args, fmt);
  1390. i = vsnprintf(buf, INT_MAX, fmt, args);
  1391. va_end(args);
  1392. return i;
  1393. }
  1394. EXPORT_SYMBOL(sprintf);
  1395. #ifdef CONFIG_BINARY_PRINTF
  1396. /*
  1397. * bprintf service:
  1398. * vbin_printf() - VA arguments to binary data
  1399. * bstr_printf() - Binary data to text string
  1400. */
  1401. /**
  1402. * vbin_printf - Parse a format string and place args' binary value in a buffer
  1403. * @bin_buf: The buffer to place args' binary value
  1404. * @size: The size of the buffer(by words(32bits), not characters)
  1405. * @fmt: The format string to use
  1406. * @args: Arguments for the format string
  1407. *
  1408. * The format follows C99 vsnprintf, except %n is ignored, and its argument
  1409. * is skiped.
  1410. *
  1411. * The return value is the number of words(32bits) which would be generated for
  1412. * the given input.
  1413. *
  1414. * NOTE:
  1415. * If the return value is greater than @size, the resulting bin_buf is NOT
  1416. * valid for bstr_printf().
  1417. */
  1418. int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
  1419. {
  1420. struct printf_spec spec = {0};
  1421. char *str, *end;
  1422. str = (char *)bin_buf;
  1423. end = (char *)(bin_buf + size);
  1424. #define save_arg(type) \
  1425. do { \
  1426. if (sizeof(type) == 8) { \
  1427. unsigned long long value; \
  1428. str = PTR_ALIGN(str, sizeof(u32)); \
  1429. value = va_arg(args, unsigned long long); \
  1430. if (str + sizeof(type) <= end) { \
  1431. *(u32 *)str = *(u32 *)&value; \
  1432. *(u32 *)(str + 4) = *((u32 *)&value + 1); \
  1433. } \
  1434. } else { \
  1435. unsigned long value; \
  1436. str = PTR_ALIGN(str, sizeof(type)); \
  1437. value = va_arg(args, int); \
  1438. if (str + sizeof(type) <= end) \
  1439. *(typeof(type) *)str = (type)value; \
  1440. } \
  1441. str += sizeof(type); \
  1442. } while (0)
  1443. while (*fmt) {
  1444. int read = format_decode(fmt, &spec);
  1445. fmt += read;
  1446. switch (spec.type) {
  1447. case FORMAT_TYPE_NONE:
  1448. case FORMAT_TYPE_INVALID:
  1449. case FORMAT_TYPE_PERCENT_CHAR:
  1450. break;
  1451. case FORMAT_TYPE_WIDTH:
  1452. case FORMAT_TYPE_PRECISION:
  1453. save_arg(int);
  1454. break;
  1455. case FORMAT_TYPE_CHAR:
  1456. save_arg(char);
  1457. break;
  1458. case FORMAT_TYPE_STR: {
  1459. const char *save_str = va_arg(args, char *);
  1460. size_t len;
  1461. if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
  1462. || (unsigned long)save_str < PAGE_SIZE)
  1463. save_str = "(null)";
  1464. len = strlen(save_str) + 1;
  1465. if (str + len < end)
  1466. memcpy(str, save_str, len);
  1467. str += len;
  1468. break;
  1469. }
  1470. case FORMAT_TYPE_PTR:
  1471. save_arg(void *);
  1472. /* skip all alphanumeric pointer suffixes */
  1473. while (isalnum(*fmt))
  1474. fmt++;
  1475. break;
  1476. case FORMAT_TYPE_NRCHARS: {
  1477. /* skip %n 's argument */
  1478. u8 qualifier = spec.qualifier;
  1479. void *skip_arg;
  1480. if (qualifier == 'l')
  1481. skip_arg = va_arg(args, long *);
  1482. else if (TOLOWER(qualifier) == 'z')
  1483. skip_arg = va_arg(args, size_t *);
  1484. else
  1485. skip_arg = va_arg(args, int *);
  1486. break;
  1487. }
  1488. default:
  1489. switch (spec.type) {
  1490. case FORMAT_TYPE_LONG_LONG:
  1491. save_arg(long long);
  1492. break;
  1493. case FORMAT_TYPE_ULONG:
  1494. case FORMAT_TYPE_LONG:
  1495. save_arg(unsigned long);
  1496. break;
  1497. case FORMAT_TYPE_SIZE_T:
  1498. save_arg(size_t);
  1499. break;
  1500. case FORMAT_TYPE_PTRDIFF:
  1501. save_arg(ptrdiff_t);
  1502. break;
  1503. case FORMAT_TYPE_UBYTE:
  1504. case FORMAT_TYPE_BYTE:
  1505. save_arg(char);
  1506. break;
  1507. case FORMAT_TYPE_USHORT:
  1508. case FORMAT_TYPE_SHORT:
  1509. save_arg(short);
  1510. break;
  1511. default:
  1512. save_arg(int);
  1513. }
  1514. }
  1515. }
  1516. return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
  1517. #undef save_arg
  1518. }
  1519. EXPORT_SYMBOL_GPL(vbin_printf);
  1520. /**
  1521. * bstr_printf - Format a string from binary arguments and place it in a buffer
  1522. * @buf: The buffer to place the result into
  1523. * @size: The size of the buffer, including the trailing null space
  1524. * @fmt: The format string to use
  1525. * @bin_buf: Binary arguments for the format string
  1526. *
  1527. * This function like C99 vsnprintf, but the difference is that vsnprintf gets
  1528. * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
  1529. * a binary buffer that generated by vbin_printf.
  1530. *
  1531. * The format follows C99 vsnprintf, but has some extensions:
  1532. * see vsnprintf comment for details.
  1533. *
  1534. * The return value is the number of characters which would
  1535. * be generated for the given input, excluding the trailing
  1536. * '\0', as per ISO C99. If you want to have the exact
  1537. * number of characters written into @buf as return value
  1538. * (not including the trailing '\0'), use vscnprintf(). If the
  1539. * return is greater than or equal to @size, the resulting
  1540. * string is truncated.
  1541. */
  1542. int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
  1543. {
  1544. struct printf_spec spec = {0};
  1545. char *str, *end;
  1546. const char *args = (const char *)bin_buf;
  1547. if (WARN_ON_ONCE((int) size < 0))
  1548. return 0;
  1549. str = buf;
  1550. end = buf + size;
  1551. #define get_arg(type) \
  1552. ({ \
  1553. typeof(type) value; \
  1554. if (sizeof(type) == 8) { \
  1555. args = PTR_ALIGN(args, sizeof(u32)); \
  1556. *(u32 *)&value = *(u32 *)args; \
  1557. *((u32 *)&value + 1) = *(u32 *)(args + 4); \
  1558. } else { \
  1559. args = PTR_ALIGN(args, sizeof(type)); \
  1560. value = *(typeof(type) *)args; \
  1561. } \
  1562. args += sizeof(type); \
  1563. value; \
  1564. })
  1565. /* Make sure end is always >= buf */
  1566. if (end < buf) {
  1567. end = ((void *)-1);
  1568. size = end - buf;
  1569. }
  1570. while (*fmt) {
  1571. const char *old_fmt = fmt;
  1572. int read = format_decode(fmt, &spec);
  1573. fmt += read;
  1574. switch (spec.type) {
  1575. case FORMAT_TYPE_NONE: {
  1576. int copy = read;
  1577. if (str < end) {
  1578. if (copy > end - str)
  1579. copy = end - str;
  1580. memcpy(str, old_fmt, copy);
  1581. }
  1582. str += read;
  1583. break;
  1584. }
  1585. case FORMAT_TYPE_WIDTH:
  1586. spec.field_width = get_arg(int);
  1587. break;
  1588. case FORMAT_TYPE_PRECISION:
  1589. spec.precision = get_arg(int);
  1590. break;
  1591. case FORMAT_TYPE_CHAR: {
  1592. char c;
  1593. if (!(spec.flags & LEFT)) {
  1594. while (--spec.field_width > 0) {
  1595. if (str < end)
  1596. *str = ' ';
  1597. ++str;
  1598. }
  1599. }
  1600. c = (unsigned char) get_arg(char);
  1601. if (str < end)
  1602. *str = c;
  1603. ++str;
  1604. while (--spec.field_width > 0) {
  1605. if (str < end)
  1606. *str = ' ';
  1607. ++str;
  1608. }
  1609. break;
  1610. }
  1611. case FORMAT_TYPE_STR: {
  1612. const char *str_arg = args;
  1613. args += strlen(str_arg) + 1;
  1614. str = string(str, end, (char *)str_arg, spec);
  1615. break;
  1616. }
  1617. case FORMAT_TYPE_PTR:
  1618. str = pointer(fmt+1, str, end, get_arg(void *), spec);
  1619. while (isalnum(*fmt))
  1620. fmt++;
  1621. break;
  1622. case FORMAT_TYPE_PERCENT_CHAR:
  1623. case FORMAT_TYPE_INVALID:
  1624. if (str < end)
  1625. *str = '%';
  1626. ++str;
  1627. break;
  1628. case FORMAT_TYPE_NRCHARS:
  1629. /* skip */
  1630. break;
  1631. default: {
  1632. unsigned long long num;
  1633. switch (spec.type) {
  1634. case FORMAT_TYPE_LONG_LONG:
  1635. num = get_arg(long long);
  1636. break;
  1637. case FORMAT_TYPE_ULONG:
  1638. case FORMAT_TYPE_LONG:
  1639. num = get_arg(unsigned long);
  1640. break;
  1641. case FORMAT_TYPE_SIZE_T:
  1642. num = get_arg(size_t);
  1643. break;
  1644. case FORMAT_TYPE_PTRDIFF:
  1645. num = get_arg(ptrdiff_t);
  1646. break;
  1647. case FORMAT_TYPE_UBYTE:
  1648. num = get_arg(unsigned char);
  1649. break;
  1650. case FORMAT_TYPE_BYTE:
  1651. num = get_arg(signed char);
  1652. break;
  1653. case FORMAT_TYPE_USHORT:
  1654. num = get_arg(unsigned short);
  1655. break;
  1656. case FORMAT_TYPE_SHORT:
  1657. num = get_arg(short);
  1658. break;
  1659. case FORMAT_TYPE_UINT:
  1660. num = get_arg(unsigned int);
  1661. break;
  1662. default:
  1663. num = get_arg(int);
  1664. }
  1665. str = number(str, end, num, spec);
  1666. } /* default: */
  1667. } /* switch(spec.type) */
  1668. } /* while(*fmt) */
  1669. if (size > 0) {
  1670. if (str < end)
  1671. *str = '\0';
  1672. else
  1673. end[-1] = '\0';
  1674. }
  1675. #undef get_arg
  1676. /* the trailing null byte doesn't count towards the total */
  1677. return str - buf;
  1678. }
  1679. EXPORT_SYMBOL_GPL(bstr_printf);
  1680. /**
  1681. * bprintf - Parse a format string and place args' binary value in a buffer
  1682. * @bin_buf: The buffer to place args' binary value
  1683. * @size: The size of the buffer(by words(32bits), not characters)
  1684. * @fmt: The format string to use
  1685. * @...: Arguments for the format string
  1686. *
  1687. * The function returns the number of words(u32) written
  1688. * into @bin_buf.
  1689. */
  1690. int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
  1691. {
  1692. va_list args;
  1693. int ret;
  1694. va_start(args, fmt);
  1695. ret = vbin_printf(bin_buf, size, fmt, args);
  1696. va_end(args);
  1697. return ret;
  1698. }
  1699. EXPORT_SYMBOL_GPL(bprintf);
  1700. #endif /* CONFIG_BINARY_PRINTF */
  1701. /**
  1702. * vsscanf - Unformat a buffer into a list of arguments
  1703. * @buf: input buffer
  1704. * @fmt: format of buffer
  1705. * @args: arguments
  1706. */
  1707. int vsscanf(const char *buf, const char *fmt, va_list args)
  1708. {
  1709. const char *str = buf;
  1710. char *next;
  1711. char digit;
  1712. int num = 0;
  1713. u8 qualifier;
  1714. u8 base;
  1715. s16 field_width;
  1716. bool is_sign;
  1717. while (*fmt && *str) {
  1718. /* skip any white space in format */
  1719. /* white space in format matchs any amount of
  1720. * white space, including none, in the input.
  1721. */
  1722. if (isspace(*fmt)) {
  1723. fmt = skip_spaces(++fmt);
  1724. str = skip_spaces(str);
  1725. }
  1726. /* anything that is not a conversion must match exactly */
  1727. if (*fmt != '%' && *fmt) {
  1728. if (*fmt++ != *str++)
  1729. break;
  1730. continue;
  1731. }
  1732. if (!*fmt)
  1733. break;
  1734. ++fmt;
  1735. /* skip this conversion.
  1736. * advance both strings to next white space
  1737. */
  1738. if (*fmt == '*') {
  1739. while (!isspace(*fmt) && *fmt != '%' && *fmt)
  1740. fmt++;
  1741. while (!isspace(*str) && *str)
  1742. str++;
  1743. continue;
  1744. }
  1745. /* get field width */
  1746. field_width = -1;
  1747. if (isdigit(*fmt))
  1748. field_width = skip_atoi(&fmt);
  1749. /* get conversion qualifier */
  1750. qualifier = -1;
  1751. if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
  1752. TOLOWER(*fmt) == 'z') {
  1753. qualifier = *fmt++;
  1754. if (unlikely(qualifier == *fmt)) {
  1755. if (qualifier == 'h') {
  1756. qualifier = 'H';
  1757. fmt++;
  1758. } else if (qualifier == 'l') {
  1759. qualifier = 'L';
  1760. fmt++;
  1761. }
  1762. }
  1763. }
  1764. if (!*fmt || !*str)
  1765. break;
  1766. base = 10;
  1767. is_sign = 0;
  1768. switch (*fmt++) {
  1769. case 'c':
  1770. {
  1771. char *s = (char *)va_arg(args, char*);
  1772. if (field_width == -1)
  1773. field_width = 1;
  1774. do {
  1775. *s++ = *str++;
  1776. } while (--field_width > 0 && *str);
  1777. num++;
  1778. }
  1779. continue;
  1780. case 's':
  1781. {
  1782. char *s = (char *)va_arg(args, char *);
  1783. if (field_width == -1)
  1784. field_width = SHRT_MAX;
  1785. /* first, skip leading white space in buffer */
  1786. str = skip_spaces(str);
  1787. /* now copy until next white space */
  1788. while (*str && !isspace(*str) && field_width--)
  1789. *s++ = *str++;
  1790. *s = '\0';
  1791. num++;
  1792. }
  1793. continue;
  1794. case 'n':
  1795. /* return number of characters read so far */
  1796. {
  1797. int *i = (int *)va_arg(args, int*);
  1798. *i = str - buf;
  1799. }
  1800. continue;
  1801. case 'o':
  1802. base = 8;
  1803. break;
  1804. case 'x':
  1805. case 'X':
  1806. base = 16;
  1807. break;
  1808. case 'i':
  1809. base = 0;
  1810. case 'd':
  1811. is_sign = 1;
  1812. case 'u':
  1813. break;
  1814. case '%':
  1815. /* looking for '%' in str */
  1816. if (*str++ != '%')
  1817. return num;
  1818. continue;
  1819. default:
  1820. /* invalid format; stop here */
  1821. return num;
  1822. }
  1823. /* have some sort of integer conversion.
  1824. * first, skip white space in buffer.
  1825. */
  1826. str = skip_spaces(str);
  1827. digit = *str;
  1828. if (is_sign && digit == '-')
  1829. digit = *(str + 1);
  1830. if (!digit
  1831. || (base == 16 && !isxdigit(digit))
  1832. || (base == 10 && !isdigit(digit))
  1833. || (base == 8 && (!isdigit(digit) || digit > '7'))
  1834. || (base == 0 && !isdigit(digit)))
  1835. break;
  1836. switch (qualifier) {
  1837. case 'H': /* that's 'hh' in format */
  1838. if (is_sign) {
  1839. signed char *s = (signed char *)va_arg(args, signed char *);
  1840. *s = (signed char)simple_strtol(str, &next, base);
  1841. } else {
  1842. unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
  1843. *s = (unsigned char)simple_strtoul(str, &next, base);
  1844. }
  1845. break;
  1846. case 'h':
  1847. if (is_sign) {
  1848. short *s = (short *)va_arg(args, short *);
  1849. *s = (short)simple_strtol(str, &next, base);
  1850. } else {
  1851. unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
  1852. *s = (unsigned short)simple_strtoul(str, &next, base);
  1853. }
  1854. break;
  1855. case 'l':
  1856. if (is_sign) {
  1857. long *l = (long *)va_arg(args, long *);
  1858. *l = simple_strtol(str, &next, base);
  1859. } else {
  1860. unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
  1861. *l = simple_strtoul(str, &next, base);
  1862. }
  1863. break;
  1864. case 'L':
  1865. if (is_sign) {
  1866. long long *l = (long long *)va_arg(args, long long *);
  1867. *l = simple_strtoll(str, &next, base);
  1868. } else {
  1869. unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
  1870. *l = simple_strtoull(str, &next, base);
  1871. }
  1872. break;
  1873. case 'Z':
  1874. case 'z':
  1875. {
  1876. size_t *s = (size_t *)va_arg(args, size_t *);
  1877. *s = (size_t)simple_strtoul(str, &next, base);
  1878. }
  1879. break;
  1880. default:
  1881. if (is_sign) {
  1882. int *i = (int *)va_arg(args, int *);
  1883. *i = (int)simple_strtol(str, &next, base);
  1884. } else {
  1885. unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
  1886. *i = (unsigned int)simple_strtoul(str, &next, base);
  1887. }
  1888. break;
  1889. }
  1890. num++;
  1891. if (!next)
  1892. break;
  1893. str = next;
  1894. }
  1895. /*
  1896. * Now we've come all the way through so either the input string or the
  1897. * format ended. In the former case, there can be a %n at the current
  1898. * position in the format that needs to be filled.
  1899. */
  1900. if (*fmt == '%' && *(fmt + 1) == 'n') {
  1901. int *p = (int *)va_arg(args, int *);
  1902. *p = str - buf;
  1903. }
  1904. return num;
  1905. }
  1906. EXPORT_SYMBOL(vsscanf);
  1907. /**
  1908. * sscanf - Unformat a buffer into a list of arguments
  1909. * @buf: input buffer
  1910. * @fmt: formatting of buffer
  1911. * @...: resulting arguments
  1912. */
  1913. int sscanf(const char *buf, const char *fmt, ...)
  1914. {
  1915. va_list args;
  1916. int i;
  1917. va_start(args, fmt);
  1918. i = vsscanf(buf, fmt, args);
  1919. va_end(args);
  1920. return i;
  1921. }
  1922. EXPORT_SYMBOL(sscanf);