mm: have order > 0 compaction start near a pageblock with free pages
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / lib / vsprintf.c
1 /*
2 * linux/lib/vsprintf.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8 /*
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
10 */
11
12 /*
13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
14 * - changed to provide snprintf and vsnprintf functions
15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
16 * - scnprintf and vscnprintf
17 */
18
19 #include <stdarg.h>
20 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/ctype.h>
24 #include <linux/kernel.h>
25 #include <linux/kallsyms.h>
26 #include <linux/uaccess.h>
27 #include <linux/ioport.h>
28 #include <net/addrconf.h>
29
30 #include <asm/page.h> /* for PAGE_SIZE */
31 #include <asm/div64.h>
32 #include <asm/sections.h> /* for dereference_function_descriptor() */
33
34 #include "kstrtox.h"
35
36 /**
37 * simple_strtoull - convert a string to an unsigned long long
38 * @cp: The start of the string
39 * @endp: A pointer to the end of the parsed string will be placed here
40 * @base: The number base to use
41 */
42 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
43 {
44 unsigned long long result;
45 unsigned int rv;
46
47 cp = _parse_integer_fixup_radix(cp, &base);
48 rv = _parse_integer(cp, base, &result);
49 /* FIXME */
50 cp += (rv & ~KSTRTOX_OVERFLOW);
51
52 if (endp)
53 *endp = (char *)cp;
54
55 return result;
56 }
57 EXPORT_SYMBOL(simple_strtoull);
58
59 /**
60 * simple_strtoul - convert a string to an unsigned long
61 * @cp: The start of the string
62 * @endp: A pointer to the end of the parsed string will be placed here
63 * @base: The number base to use
64 */
65 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
66 {
67 return simple_strtoull(cp, endp, base);
68 }
69 EXPORT_SYMBOL(simple_strtoul);
70
71 /**
72 * simple_strtol - convert a string to a signed long
73 * @cp: The start of the string
74 * @endp: A pointer to the end of the parsed string will be placed here
75 * @base: The number base to use
76 */
77 long simple_strtol(const char *cp, char **endp, unsigned int base)
78 {
79 if (*cp == '-')
80 return -simple_strtoul(cp + 1, endp, base);
81
82 return simple_strtoul(cp, endp, base);
83 }
84 EXPORT_SYMBOL(simple_strtol);
85
86 /**
87 * simple_strtoll - convert a string to a signed long long
88 * @cp: The start of the string
89 * @endp: A pointer to the end of the parsed string will be placed here
90 * @base: The number base to use
91 */
92 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
93 {
94 if (*cp == '-')
95 return -simple_strtoull(cp + 1, endp, base);
96
97 return simple_strtoull(cp, endp, base);
98 }
99 EXPORT_SYMBOL(simple_strtoll);
100
101 static noinline_for_stack
102 int skip_atoi(const char **s)
103 {
104 int i = 0;
105
106 while (isdigit(**s))
107 i = i*10 + *((*s)++) - '0';
108
109 return i;
110 }
111
112 /* Decimal conversion is by far the most typical, and is used
113 * for /proc and /sys data. This directly impacts e.g. top performance
114 * with many processes running. We optimize it for speed
115 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
116 * (with permission from the author, Douglas W. Jones).
117 */
118
119 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
120 /* Formats correctly any integer in [0, 999999999] */
121 static noinline_for_stack
122 char *put_dec_full9(char *buf, unsigned q)
123 {
124 unsigned r;
125
126 /*
127 * Possible ways to approx. divide by 10
128 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
129 * (x * 0xcccd) >> 19 x < 81920 (x < 262149 when 64-bit mul)
130 * (x * 0x6667) >> 18 x < 43699
131 * (x * 0x3334) >> 17 x < 16389
132 * (x * 0x199a) >> 16 x < 16389
133 * (x * 0x0ccd) >> 15 x < 16389
134 * (x * 0x0667) >> 14 x < 2739
135 * (x * 0x0334) >> 13 x < 1029
136 * (x * 0x019a) >> 12 x < 1029
137 * (x * 0x00cd) >> 11 x < 1029 shorter code than * 0x67 (on i386)
138 * (x * 0x0067) >> 10 x < 179
139 * (x * 0x0034) >> 9 x < 69 same
140 * (x * 0x001a) >> 8 x < 69 same
141 * (x * 0x000d) >> 7 x < 69 same, shortest code (on i386)
142 * (x * 0x0007) >> 6 x < 19
143 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
144 */
145 r = (q * (uint64_t)0x1999999a) >> 32;
146 *buf++ = (q - 10 * r) + '0'; /* 1 */
147 q = (r * (uint64_t)0x1999999a) >> 32;
148 *buf++ = (r - 10 * q) + '0'; /* 2 */
149 r = (q * (uint64_t)0x1999999a) >> 32;
150 *buf++ = (q - 10 * r) + '0'; /* 3 */
151 q = (r * (uint64_t)0x1999999a) >> 32;
152 *buf++ = (r - 10 * q) + '0'; /* 4 */
153 r = (q * (uint64_t)0x1999999a) >> 32;
154 *buf++ = (q - 10 * r) + '0'; /* 5 */
155 /* Now value is under 10000, can avoid 64-bit multiply */
156 q = (r * 0x199a) >> 16;
157 *buf++ = (r - 10 * q) + '0'; /* 6 */
158 r = (q * 0xcd) >> 11;
159 *buf++ = (q - 10 * r) + '0'; /* 7 */
160 q = (r * 0xcd) >> 11;
161 *buf++ = (r - 10 * q) + '0'; /* 8 */
162 *buf++ = q + '0'; /* 9 */
163 return buf;
164 }
165 #endif
166
167 /* Similar to above but do not pad with zeros.
168 * Code can be easily arranged to print 9 digits too, but our callers
169 * always call put_dec_full9() instead when the number has 9 decimal digits.
170 */
171 static noinline_for_stack
172 char *put_dec_trunc8(char *buf, unsigned r)
173 {
174 unsigned q;
175
176 /* Copy of previous function's body with added early returns */
177 q = (r * (uint64_t)0x1999999a) >> 32;
178 *buf++ = (r - 10 * q) + '0'; /* 2 */
179 if (q == 0)
180 return buf;
181 r = (q * (uint64_t)0x1999999a) >> 32;
182 *buf++ = (q - 10 * r) + '0'; /* 3 */
183 if (r == 0)
184 return buf;
185 q = (r * (uint64_t)0x1999999a) >> 32;
186 *buf++ = (r - 10 * q) + '0'; /* 4 */
187 if (q == 0)
188 return buf;
189 r = (q * (uint64_t)0x1999999a) >> 32;
190 *buf++ = (q - 10 * r) + '0'; /* 5 */
191 if (r == 0)
192 return buf;
193 q = (r * 0x199a) >> 16;
194 *buf++ = (r - 10 * q) + '0'; /* 6 */
195 if (q == 0)
196 return buf;
197 r = (q * 0xcd) >> 11;
198 *buf++ = (q - 10 * r) + '0'; /* 7 */
199 if (r == 0)
200 return buf;
201 q = (r * 0xcd) >> 11;
202 *buf++ = (r - 10 * q) + '0'; /* 8 */
203 if (q == 0)
204 return buf;
205 *buf++ = q + '0'; /* 9 */
206 return buf;
207 }
208
209 /* There are two algorithms to print larger numbers.
210 * One is generic: divide by 1000000000 and repeatedly print
211 * groups of (up to) 9 digits. It's conceptually simple,
212 * but requires a (unsigned long long) / 1000000000 division.
213 *
214 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
215 * manipulates them cleverly and generates groups of 4 decimal digits.
216 * It so happens that it does NOT require long long division.
217 *
218 * If long is > 32 bits, division of 64-bit values is relatively easy,
219 * and we will use the first algorithm.
220 * If long long is > 64 bits (strange architecture with VERY large long long),
221 * second algorithm can't be used, and we again use the first one.
222 *
223 * Else (if long is 32 bits and long long is 64 bits) we use second one.
224 */
225
226 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
227
228 /* First algorithm: generic */
229
230 static
231 char *put_dec(char *buf, unsigned long long n)
232 {
233 if (n >= 100*1000*1000) {
234 while (n >= 1000*1000*1000)
235 buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
236 if (n >= 100*1000*1000)
237 return put_dec_full9(buf, n);
238 }
239 return put_dec_trunc8(buf, n);
240 }
241
242 #else
243
244 /* Second algorithm: valid only for 64-bit long longs */
245
246 static noinline_for_stack
247 char *put_dec_full4(char *buf, unsigned q)
248 {
249 unsigned r;
250 r = (q * 0xcccd) >> 19;
251 *buf++ = (q - 10 * r) + '0';
252 q = (r * 0x199a) >> 16;
253 *buf++ = (r - 10 * q) + '0';
254 r = (q * 0xcd) >> 11;
255 *buf++ = (q - 10 * r) + '0';
256 *buf++ = r + '0';
257 return buf;
258 }
259
260 /* Based on code by Douglas W. Jones found at
261 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
262 * (with permission from the author).
263 * Performs no 64-bit division and hence should be fast on 32-bit machines.
264 */
265 static
266 char *put_dec(char *buf, unsigned long long n)
267 {
268 uint32_t d3, d2, d1, q, h;
269
270 if (n < 100*1000*1000)
271 return put_dec_trunc8(buf, n);
272
273 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
274 h = (n >> 32);
275 d2 = (h ) & 0xffff;
276 d3 = (h >> 16); /* implicit "& 0xffff" */
277
278 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
279
280 buf = put_dec_full4(buf, q % 10000);
281 q = q / 10000;
282
283 d1 = q + 7671 * d3 + 9496 * d2 + 6 * d1;
284 buf = put_dec_full4(buf, d1 % 10000);
285 q = d1 / 10000;
286
287 d2 = q + 4749 * d3 + 42 * d2;
288 buf = put_dec_full4(buf, d2 % 10000);
289 q = d2 / 10000;
290
291 d3 = q + 281 * d3;
292 if (!d3)
293 goto done;
294 buf = put_dec_full4(buf, d3 % 10000);
295 q = d3 / 10000;
296 if (!q)
297 goto done;
298 buf = put_dec_full4(buf, q);
299 done:
300 while (buf[-1] == '0')
301 --buf;
302
303 return buf;
304 }
305
306 #endif
307
308 /*
309 * Convert passed number to decimal string.
310 * Returns the length of string. On buffer overflow, returns 0.
311 *
312 * If speed is not important, use snprintf(). It's easy to read the code.
313 */
314 int num_to_str(char *buf, int size, unsigned long long num)
315 {
316 char tmp[sizeof(num) * 3];
317 int idx, len;
318
319 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
320 if (num <= 9) {
321 tmp[0] = '0' + num;
322 len = 1;
323 } else {
324 len = put_dec(tmp, num) - tmp;
325 }
326
327 if (len > size)
328 return 0;
329 for (idx = 0; idx < len; ++idx)
330 buf[idx] = tmp[len - idx - 1];
331 return len;
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
342 enum format_type {
343 FORMAT_TYPE_NONE, /* Just a string part */
344 FORMAT_TYPE_WIDTH,
345 FORMAT_TYPE_PRECISION,
346 FORMAT_TYPE_CHAR,
347 FORMAT_TYPE_STR,
348 FORMAT_TYPE_PTR,
349 FORMAT_TYPE_PERCENT_CHAR,
350 FORMAT_TYPE_INVALID,
351 FORMAT_TYPE_LONG_LONG,
352 FORMAT_TYPE_ULONG,
353 FORMAT_TYPE_LONG,
354 FORMAT_TYPE_UBYTE,
355 FORMAT_TYPE_BYTE,
356 FORMAT_TYPE_USHORT,
357 FORMAT_TYPE_SHORT,
358 FORMAT_TYPE_UINT,
359 FORMAT_TYPE_INT,
360 FORMAT_TYPE_NRCHARS,
361 FORMAT_TYPE_SIZE_T,
362 FORMAT_TYPE_PTRDIFF
363 };
364
365 struct printf_spec {
366 u8 type; /* format_type enum */
367 u8 flags; /* flags to number() */
368 u8 base; /* number base, 8, 10 or 16 only */
369 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */
370 s16 field_width; /* width of output field */
371 s16 precision; /* # of digits/chars */
372 };
373
374 static noinline_for_stack
375 char *number(char *buf, char *end, unsigned long long num,
376 struct printf_spec spec)
377 {
378 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
379 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
380
381 char tmp[66];
382 char sign;
383 char locase;
384 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
385 int i;
386 bool is_zero = num == 0LL;
387
388 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
389 * produces same digits or (maybe lowercased) letters */
390 locase = (spec.flags & SMALL);
391 if (spec.flags & LEFT)
392 spec.flags &= ~ZEROPAD;
393 sign = 0;
394 if (spec.flags & SIGN) {
395 if ((signed long long)num < 0) {
396 sign = '-';
397 num = -(signed long long)num;
398 spec.field_width--;
399 } else if (spec.flags & PLUS) {
400 sign = '+';
401 spec.field_width--;
402 } else if (spec.flags & SPACE) {
403 sign = ' ';
404 spec.field_width--;
405 }
406 }
407 if (need_pfx) {
408 if (spec.base == 16)
409 spec.field_width -= 2;
410 else if (!is_zero)
411 spec.field_width--;
412 }
413
414 /* generate full string in tmp[], in reverse order */
415 i = 0;
416 if (num < spec.base)
417 tmp[i++] = digits[num] | locase;
418 /* Generic code, for any base:
419 else do {
420 tmp[i++] = (digits[do_div(num,base)] | locase);
421 } while (num != 0);
422 */
423 else if (spec.base != 10) { /* 8 or 16 */
424 int mask = spec.base - 1;
425 int shift = 3;
426
427 if (spec.base == 16)
428 shift = 4;
429 do {
430 tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
431 num >>= shift;
432 } while (num);
433 } else { /* base 10 */
434 i = put_dec(tmp, num) - tmp;
435 }
436
437 /* printing 100 using %2d gives "100", not "00" */
438 if (i > spec.precision)
439 spec.precision = i;
440 /* leading space padding */
441 spec.field_width -= spec.precision;
442 if (!(spec.flags & (ZEROPAD+LEFT))) {
443 while (--spec.field_width >= 0) {
444 if (buf < end)
445 *buf = ' ';
446 ++buf;
447 }
448 }
449 /* sign */
450 if (sign) {
451 if (buf < end)
452 *buf = sign;
453 ++buf;
454 }
455 /* "0x" / "0" prefix */
456 if (need_pfx) {
457 if (spec.base == 16 || !is_zero) {
458 if (buf < end)
459 *buf = '0';
460 ++buf;
461 }
462 if (spec.base == 16) {
463 if (buf < end)
464 *buf = ('X' | locase);
465 ++buf;
466 }
467 }
468 /* zero or space padding */
469 if (!(spec.flags & LEFT)) {
470 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
471 while (--spec.field_width >= 0) {
472 if (buf < end)
473 *buf = c;
474 ++buf;
475 }
476 }
477 /* hmm even more zero padding? */
478 while (i <= --spec.precision) {
479 if (buf < end)
480 *buf = '0';
481 ++buf;
482 }
483 /* actual digits of result */
484 while (--i >= 0) {
485 if (buf < end)
486 *buf = tmp[i];
487 ++buf;
488 }
489 /* trailing space padding */
490 while (--spec.field_width >= 0) {
491 if (buf < end)
492 *buf = ' ';
493 ++buf;
494 }
495
496 return buf;
497 }
498
499 static noinline_for_stack
500 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
501 {
502 int len, i;
503
504 if ((unsigned long)s < PAGE_SIZE)
505 s = "(null)";
506
507 len = strnlen(s, spec.precision);
508
509 if (!(spec.flags & LEFT)) {
510 while (len < spec.field_width--) {
511 if (buf < end)
512 *buf = ' ';
513 ++buf;
514 }
515 }
516 for (i = 0; i < len; ++i) {
517 if (buf < end)
518 *buf = *s;
519 ++buf; ++s;
520 }
521 while (len < spec.field_width--) {
522 if (buf < end)
523 *buf = ' ';
524 ++buf;
525 }
526
527 return buf;
528 }
529
530 static noinline_for_stack
531 char *symbol_string(char *buf, char *end, void *ptr,
532 struct printf_spec spec, char ext)
533 {
534 unsigned long value = (unsigned long) ptr;
535 #ifdef CONFIG_KALLSYMS
536 char sym[KSYM_SYMBOL_LEN];
537 if (ext == 'B')
538 sprint_backtrace(sym, value);
539 else if (ext != 'f' && ext != 's')
540 sprint_symbol(sym, value);
541 else
542 sprint_symbol_no_offset(sym, value);
543
544 return string(buf, end, sym, spec);
545 #else
546 spec.field_width = 2 * sizeof(void *);
547 spec.flags |= SPECIAL | SMALL | ZEROPAD;
548 spec.base = 16;
549
550 return number(buf, end, value, spec);
551 #endif
552 }
553
554 static noinline_for_stack
555 char *resource_string(char *buf, char *end, struct resource *res,
556 struct printf_spec spec, const char *fmt)
557 {
558 #ifndef IO_RSRC_PRINTK_SIZE
559 #define IO_RSRC_PRINTK_SIZE 6
560 #endif
561
562 #ifndef MEM_RSRC_PRINTK_SIZE
563 #define MEM_RSRC_PRINTK_SIZE 10
564 #endif
565 static const struct printf_spec io_spec = {
566 .base = 16,
567 .field_width = IO_RSRC_PRINTK_SIZE,
568 .precision = -1,
569 .flags = SPECIAL | SMALL | ZEROPAD,
570 };
571 static const struct printf_spec mem_spec = {
572 .base = 16,
573 .field_width = MEM_RSRC_PRINTK_SIZE,
574 .precision = -1,
575 .flags = SPECIAL | SMALL | ZEROPAD,
576 };
577 static const struct printf_spec bus_spec = {
578 .base = 16,
579 .field_width = 2,
580 .precision = -1,
581 .flags = SMALL | ZEROPAD,
582 };
583 static const struct printf_spec dec_spec = {
584 .base = 10,
585 .precision = -1,
586 .flags = 0,
587 };
588 static const struct printf_spec str_spec = {
589 .field_width = -1,
590 .precision = 10,
591 .flags = LEFT,
592 };
593 static const struct printf_spec flag_spec = {
594 .base = 16,
595 .precision = -1,
596 .flags = SPECIAL | SMALL,
597 };
598
599 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
600 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
601 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
602 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
603 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
604 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
605 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
606 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
607
608 char *p = sym, *pend = sym + sizeof(sym);
609 int decode = (fmt[0] == 'R') ? 1 : 0;
610 const struct printf_spec *specp;
611
612 *p++ = '[';
613 if (res->flags & IORESOURCE_IO) {
614 p = string(p, pend, "io ", str_spec);
615 specp = &io_spec;
616 } else if (res->flags & IORESOURCE_MEM) {
617 p = string(p, pend, "mem ", str_spec);
618 specp = &mem_spec;
619 } else if (res->flags & IORESOURCE_IRQ) {
620 p = string(p, pend, "irq ", str_spec);
621 specp = &dec_spec;
622 } else if (res->flags & IORESOURCE_DMA) {
623 p = string(p, pend, "dma ", str_spec);
624 specp = &dec_spec;
625 } else if (res->flags & IORESOURCE_BUS) {
626 p = string(p, pend, "bus ", str_spec);
627 specp = &bus_spec;
628 } else {
629 p = string(p, pend, "??? ", str_spec);
630 specp = &mem_spec;
631 decode = 0;
632 }
633 p = number(p, pend, res->start, *specp);
634 if (res->start != res->end) {
635 *p++ = '-';
636 p = number(p, pend, res->end, *specp);
637 }
638 if (decode) {
639 if (res->flags & IORESOURCE_MEM_64)
640 p = string(p, pend, " 64bit", str_spec);
641 if (res->flags & IORESOURCE_PREFETCH)
642 p = string(p, pend, " pref", str_spec);
643 if (res->flags & IORESOURCE_WINDOW)
644 p = string(p, pend, " window", str_spec);
645 if (res->flags & IORESOURCE_DISABLED)
646 p = string(p, pend, " disabled", str_spec);
647 } else {
648 p = string(p, pend, " flags ", str_spec);
649 p = number(p, pend, res->flags, flag_spec);
650 }
651 *p++ = ']';
652 *p = '\0';
653
654 return string(buf, end, sym, spec);
655 }
656
657 static noinline_for_stack
658 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
659 const char *fmt)
660 {
661 int i, len = 1; /* if we pass '%ph[CDN]', field witdh remains
662 negative value, fallback to the default */
663 char separator;
664
665 if (spec.field_width == 0)
666 /* nothing to print */
667 return buf;
668
669 if (ZERO_OR_NULL_PTR(addr))
670 /* NULL pointer */
671 return string(buf, end, NULL, spec);
672
673 switch (fmt[1]) {
674 case 'C':
675 separator = ':';
676 break;
677 case 'D':
678 separator = '-';
679 break;
680 case 'N':
681 separator = 0;
682 break;
683 default:
684 separator = ' ';
685 break;
686 }
687
688 if (spec.field_width > 0)
689 len = min_t(int, spec.field_width, 64);
690
691 for (i = 0; i < len && buf < end - 1; i++) {
692 buf = hex_byte_pack(buf, addr[i]);
693
694 if (buf < end && separator && i != len - 1)
695 *buf++ = separator;
696 }
697
698 return buf;
699 }
700
701 static noinline_for_stack
702 char *mac_address_string(char *buf, char *end, u8 *addr,
703 struct printf_spec spec, const char *fmt)
704 {
705 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
706 char *p = mac_addr;
707 int i;
708 char separator;
709 bool reversed = false;
710
711 switch (fmt[1]) {
712 case 'F':
713 separator = '-';
714 break;
715
716 case 'R':
717 reversed = true;
718 /* fall through */
719
720 default:
721 separator = ':';
722 break;
723 }
724
725 for (i = 0; i < 6; i++) {
726 if (reversed)
727 p = hex_byte_pack(p, addr[5 - i]);
728 else
729 p = hex_byte_pack(p, addr[i]);
730
731 if (fmt[0] == 'M' && i != 5)
732 *p++ = separator;
733 }
734 *p = '\0';
735
736 return string(buf, end, mac_addr, spec);
737 }
738
739 static noinline_for_stack
740 char *ip4_string(char *p, const u8 *addr, const char *fmt)
741 {
742 int i;
743 bool leading_zeros = (fmt[0] == 'i');
744 int index;
745 int step;
746
747 switch (fmt[2]) {
748 case 'h':
749 #ifdef __BIG_ENDIAN
750 index = 0;
751 step = 1;
752 #else
753 index = 3;
754 step = -1;
755 #endif
756 break;
757 case 'l':
758 index = 3;
759 step = -1;
760 break;
761 case 'n':
762 case 'b':
763 default:
764 index = 0;
765 step = 1;
766 break;
767 }
768 for (i = 0; i < 4; i++) {
769 char temp[3]; /* hold each IP quad in reverse order */
770 int digits = put_dec_trunc8(temp, addr[index]) - temp;
771 if (leading_zeros) {
772 if (digits < 3)
773 *p++ = '0';
774 if (digits < 2)
775 *p++ = '0';
776 }
777 /* reverse the digits in the quad */
778 while (digits--)
779 *p++ = temp[digits];
780 if (i < 3)
781 *p++ = '.';
782 index += step;
783 }
784 *p = '\0';
785
786 return p;
787 }
788
789 static noinline_for_stack
790 char *ip6_compressed_string(char *p, const char *addr)
791 {
792 int i, j, range;
793 unsigned char zerolength[8];
794 int longest = 1;
795 int colonpos = -1;
796 u16 word;
797 u8 hi, lo;
798 bool needcolon = false;
799 bool useIPv4;
800 struct in6_addr in6;
801
802 memcpy(&in6, addr, sizeof(struct in6_addr));
803
804 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
805
806 memset(zerolength, 0, sizeof(zerolength));
807
808 if (useIPv4)
809 range = 6;
810 else
811 range = 8;
812
813 /* find position of longest 0 run */
814 for (i = 0; i < range; i++) {
815 for (j = i; j < range; j++) {
816 if (in6.s6_addr16[j] != 0)
817 break;
818 zerolength[i]++;
819 }
820 }
821 for (i = 0; i < range; i++) {
822 if (zerolength[i] > longest) {
823 longest = zerolength[i];
824 colonpos = i;
825 }
826 }
827 if (longest == 1) /* don't compress a single 0 */
828 colonpos = -1;
829
830 /* emit address */
831 for (i = 0; i < range; i++) {
832 if (i == colonpos) {
833 if (needcolon || i == 0)
834 *p++ = ':';
835 *p++ = ':';
836 needcolon = false;
837 i += longest - 1;
838 continue;
839 }
840 if (needcolon) {
841 *p++ = ':';
842 needcolon = false;
843 }
844 /* hex u16 without leading 0s */
845 word = ntohs(in6.s6_addr16[i]);
846 hi = word >> 8;
847 lo = word & 0xff;
848 if (hi) {
849 if (hi > 0x0f)
850 p = hex_byte_pack(p, hi);
851 else
852 *p++ = hex_asc_lo(hi);
853 p = hex_byte_pack(p, lo);
854 }
855 else if (lo > 0x0f)
856 p = hex_byte_pack(p, lo);
857 else
858 *p++ = hex_asc_lo(lo);
859 needcolon = true;
860 }
861
862 if (useIPv4) {
863 if (needcolon)
864 *p++ = ':';
865 p = ip4_string(p, &in6.s6_addr[12], "I4");
866 }
867 *p = '\0';
868
869 return p;
870 }
871
872 static noinline_for_stack
873 char *ip6_string(char *p, const char *addr, const char *fmt)
874 {
875 int i;
876
877 for (i = 0; i < 8; i++) {
878 p = hex_byte_pack(p, *addr++);
879 p = hex_byte_pack(p, *addr++);
880 if (fmt[0] == 'I' && i != 7)
881 *p++ = ':';
882 }
883 *p = '\0';
884
885 return p;
886 }
887
888 static noinline_for_stack
889 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
890 struct printf_spec spec, const char *fmt)
891 {
892 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
893
894 if (fmt[0] == 'I' && fmt[2] == 'c')
895 ip6_compressed_string(ip6_addr, addr);
896 else
897 ip6_string(ip6_addr, addr, fmt);
898
899 return string(buf, end, ip6_addr, spec);
900 }
901
902 static noinline_for_stack
903 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
904 struct printf_spec spec, const char *fmt)
905 {
906 char ip4_addr[sizeof("255.255.255.255")];
907
908 ip4_string(ip4_addr, addr, fmt);
909
910 return string(buf, end, ip4_addr, spec);
911 }
912
913 static noinline_for_stack
914 char *uuid_string(char *buf, char *end, const u8 *addr,
915 struct printf_spec spec, const char *fmt)
916 {
917 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
918 char *p = uuid;
919 int i;
920 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
921 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
922 const u8 *index = be;
923 bool uc = false;
924
925 switch (*(++fmt)) {
926 case 'L':
927 uc = true; /* fall-through */
928 case 'l':
929 index = le;
930 break;
931 case 'B':
932 uc = true;
933 break;
934 }
935
936 for (i = 0; i < 16; i++) {
937 p = hex_byte_pack(p, addr[index[i]]);
938 switch (i) {
939 case 3:
940 case 5:
941 case 7:
942 case 9:
943 *p++ = '-';
944 break;
945 }
946 }
947
948 *p = 0;
949
950 if (uc) {
951 p = uuid;
952 do {
953 *p = toupper(*p);
954 } while (*(++p));
955 }
956
957 return string(buf, end, uuid, spec);
958 }
959
960 static
961 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
962 struct printf_spec spec)
963 {
964 spec.flags |= SPECIAL | SMALL | ZEROPAD;
965 if (spec.field_width == -1)
966 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
967 spec.base = 16;
968
969 return number(buf, end, *(const netdev_features_t *)addr, spec);
970 }
971
972 int kptr_restrict __read_mostly;
973
974 /*
975 * Show a '%p' thing. A kernel extension is that the '%p' is followed
976 * by an extra set of alphanumeric characters that are extended format
977 * specifiers.
978 *
979 * Right now we handle:
980 *
981 * - 'F' For symbolic function descriptor pointers with offset
982 * - 'f' For simple symbolic function names without offset
983 * - 'S' For symbolic direct pointers with offset
984 * - 's' For symbolic direct pointers without offset
985 * - 'B' For backtraced symbolic direct pointers with offset
986 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
987 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
988 * - 'M' For a 6-byte MAC address, it prints the address in the
989 * usual colon-separated hex notation
990 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
991 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
992 * with a dash-separated hex notation
993 * - '[mM]R For a 6-byte MAC address, Reverse order (Bluetooth)
994 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
995 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
996 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
997 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
998 * IPv6 omits the colons (01020304...0f)
999 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1000 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
1001 * - 'I6c' for IPv6 addresses printed as specified by
1002 * http://tools.ietf.org/html/rfc5952
1003 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1004 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1005 * Options for %pU are:
1006 * b big endian lower case hex (default)
1007 * B big endian UPPER case hex
1008 * l little endian lower case hex
1009 * L little endian UPPER case hex
1010 * big endian output byte order is:
1011 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1012 * little endian output byte order is:
1013 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1014 * - 'V' For a struct va_format which contains a format string * and va_list *,
1015 * call vsnprintf(->format, *->va_list).
1016 * Implements a "recursive vsnprintf".
1017 * Do not use this feature without some mechanism to verify the
1018 * correctness of the format string and va_list arguments.
1019 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1020 * - 'NF' For a netdev_features_t
1021 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1022 * a certain separator (' ' by default):
1023 * C colon
1024 * D dash
1025 * N no separator
1026 * The maximum supported length is 64 bytes of the input. Consider
1027 * to use print_hex_dump() for the larger input.
1028 *
1029 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1030 * function pointers are really function descriptors, which contain a
1031 * pointer to the real address.
1032 */
1033 static noinline_for_stack
1034 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1035 struct printf_spec spec)
1036 {
1037 int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1038
1039 if (!ptr && *fmt != 'K') {
1040 /*
1041 * Print (null) with the same width as a pointer so it makes
1042 * tabular output look nice.
1043 */
1044 if (spec.field_width == -1)
1045 spec.field_width = default_width;
1046 return string(buf, end, "(null)", spec);
1047 }
1048
1049 switch (*fmt) {
1050 case 'F':
1051 case 'f':
1052 ptr = dereference_function_descriptor(ptr);
1053 /* Fallthrough */
1054 case 'S':
1055 case 's':
1056 case 'B':
1057 return symbol_string(buf, end, ptr, spec, *fmt);
1058 case 'R':
1059 case 'r':
1060 return resource_string(buf, end, ptr, spec, fmt);
1061 case 'h':
1062 return hex_string(buf, end, ptr, spec, fmt);
1063 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1064 case 'm': /* Contiguous: 000102030405 */
1065 /* [mM]F (FDDI) */
1066 /* [mM]R (Reverse order; Bluetooth) */
1067 return mac_address_string(buf, end, ptr, spec, fmt);
1068 case 'I': /* Formatted IP supported
1069 * 4: 1.2.3.4
1070 * 6: 0001:0203:...:0708
1071 * 6c: 1::708 or 1::1.2.3.4
1072 */
1073 case 'i': /* Contiguous:
1074 * 4: 001.002.003.004
1075 * 6: 000102...0f
1076 */
1077 switch (fmt[1]) {
1078 case '6':
1079 return ip6_addr_string(buf, end, ptr, spec, fmt);
1080 case '4':
1081 return ip4_addr_string(buf, end, ptr, spec, fmt);
1082 }
1083 break;
1084 case 'U':
1085 return uuid_string(buf, end, ptr, spec, fmt);
1086 case 'V':
1087 {
1088 va_list va;
1089
1090 va_copy(va, *((struct va_format *)ptr)->va);
1091 buf += vsnprintf(buf, end > buf ? end - buf : 0,
1092 ((struct va_format *)ptr)->fmt, va);
1093 va_end(va);
1094 return buf;
1095 }
1096 case 'K':
1097 /*
1098 * %pK cannot be used in IRQ context because its test
1099 * for CAP_SYSLOG would be meaningless.
1100 */
1101 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1102 in_nmi())) {
1103 if (spec.field_width == -1)
1104 spec.field_width = default_width;
1105 return string(buf, end, "pK-error", spec);
1106 }
1107 if (!((kptr_restrict == 0) ||
1108 (kptr_restrict == 1 &&
1109 has_capability_noaudit(current, CAP_SYSLOG))))
1110 ptr = NULL;
1111 break;
1112 case 'N':
1113 switch (fmt[1]) {
1114 case 'F':
1115 return netdev_feature_string(buf, end, ptr, spec);
1116 }
1117 break;
1118 }
1119 spec.flags |= SMALL;
1120 if (spec.field_width == -1) {
1121 spec.field_width = default_width;
1122 spec.flags |= ZEROPAD;
1123 }
1124 spec.base = 16;
1125
1126 return number(buf, end, (unsigned long) ptr, spec);
1127 }
1128
1129 /*
1130 * Helper function to decode printf style format.
1131 * Each call decode a token from the format and return the
1132 * number of characters read (or likely the delta where it wants
1133 * to go on the next call).
1134 * The decoded token is returned through the parameters
1135 *
1136 * 'h', 'l', or 'L' for integer fields
1137 * 'z' support added 23/7/1999 S.H.
1138 * 'z' changed to 'Z' --davidm 1/25/99
1139 * 't' added for ptrdiff_t
1140 *
1141 * @fmt: the format string
1142 * @type of the token returned
1143 * @flags: various flags such as +, -, # tokens..
1144 * @field_width: overwritten width
1145 * @base: base of the number (octal, hex, ...)
1146 * @precision: precision of a number
1147 * @qualifier: qualifier of a number (long, size_t, ...)
1148 */
1149 static noinline_for_stack
1150 int format_decode(const char *fmt, struct printf_spec *spec)
1151 {
1152 const char *start = fmt;
1153
1154 /* we finished early by reading the field width */
1155 if (spec->type == FORMAT_TYPE_WIDTH) {
1156 if (spec->field_width < 0) {
1157 spec->field_width = -spec->field_width;
1158 spec->flags |= LEFT;
1159 }
1160 spec->type = FORMAT_TYPE_NONE;
1161 goto precision;
1162 }
1163
1164 /* we finished early by reading the precision */
1165 if (spec->type == FORMAT_TYPE_PRECISION) {
1166 if (spec->precision < 0)
1167 spec->precision = 0;
1168
1169 spec->type = FORMAT_TYPE_NONE;
1170 goto qualifier;
1171 }
1172
1173 /* By default */
1174 spec->type = FORMAT_TYPE_NONE;
1175
1176 for (; *fmt ; ++fmt) {
1177 if (*fmt == '%')
1178 break;
1179 }
1180
1181 /* Return the current non-format string */
1182 if (fmt != start || !*fmt)
1183 return fmt - start;
1184
1185 /* Process flags */
1186 spec->flags = 0;
1187
1188 while (1) { /* this also skips first '%' */
1189 bool found = true;
1190
1191 ++fmt;
1192
1193 switch (*fmt) {
1194 case '-': spec->flags |= LEFT; break;
1195 case '+': spec->flags |= PLUS; break;
1196 case ' ': spec->flags |= SPACE; break;
1197 case '#': spec->flags |= SPECIAL; break;
1198 case '0': spec->flags |= ZEROPAD; break;
1199 default: found = false;
1200 }
1201
1202 if (!found)
1203 break;
1204 }
1205
1206 /* get field width */
1207 spec->field_width = -1;
1208
1209 if (isdigit(*fmt))
1210 spec->field_width = skip_atoi(&fmt);
1211 else if (*fmt == '*') {
1212 /* it's the next argument */
1213 spec->type = FORMAT_TYPE_WIDTH;
1214 return ++fmt - start;
1215 }
1216
1217 precision:
1218 /* get the precision */
1219 spec->precision = -1;
1220 if (*fmt == '.') {
1221 ++fmt;
1222 if (isdigit(*fmt)) {
1223 spec->precision = skip_atoi(&fmt);
1224 if (spec->precision < 0)
1225 spec->precision = 0;
1226 } else if (*fmt == '*') {
1227 /* it's the next argument */
1228 spec->type = FORMAT_TYPE_PRECISION;
1229 return ++fmt - start;
1230 }
1231 }
1232
1233 qualifier:
1234 /* get the conversion qualifier */
1235 spec->qualifier = -1;
1236 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1237 _tolower(*fmt) == 'z' || *fmt == 't') {
1238 spec->qualifier = *fmt++;
1239 if (unlikely(spec->qualifier == *fmt)) {
1240 if (spec->qualifier == 'l') {
1241 spec->qualifier = 'L';
1242 ++fmt;
1243 } else if (spec->qualifier == 'h') {
1244 spec->qualifier = 'H';
1245 ++fmt;
1246 }
1247 }
1248 }
1249
1250 /* default base */
1251 spec->base = 10;
1252 switch (*fmt) {
1253 case 'c':
1254 spec->type = FORMAT_TYPE_CHAR;
1255 return ++fmt - start;
1256
1257 case 's':
1258 spec->type = FORMAT_TYPE_STR;
1259 return ++fmt - start;
1260
1261 case 'p':
1262 spec->type = FORMAT_TYPE_PTR;
1263 return fmt - start;
1264 /* skip alnum */
1265
1266 case 'n':
1267 spec->type = FORMAT_TYPE_NRCHARS;
1268 return ++fmt - start;
1269
1270 case '%':
1271 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1272 return ++fmt - start;
1273
1274 /* integer number formats - set up the flags and "break" */
1275 case 'o':
1276 spec->base = 8;
1277 break;
1278
1279 case 'x':
1280 spec->flags |= SMALL;
1281
1282 case 'X':
1283 spec->base = 16;
1284 break;
1285
1286 case 'd':
1287 case 'i':
1288 spec->flags |= SIGN;
1289 case 'u':
1290 break;
1291
1292 default:
1293 spec->type = FORMAT_TYPE_INVALID;
1294 return fmt - start;
1295 }
1296
1297 if (spec->qualifier == 'L')
1298 spec->type = FORMAT_TYPE_LONG_LONG;
1299 else if (spec->qualifier == 'l') {
1300 if (spec->flags & SIGN)
1301 spec->type = FORMAT_TYPE_LONG;
1302 else
1303 spec->type = FORMAT_TYPE_ULONG;
1304 } else if (_tolower(spec->qualifier) == 'z') {
1305 spec->type = FORMAT_TYPE_SIZE_T;
1306 } else if (spec->qualifier == 't') {
1307 spec->type = FORMAT_TYPE_PTRDIFF;
1308 } else if (spec->qualifier == 'H') {
1309 if (spec->flags & SIGN)
1310 spec->type = FORMAT_TYPE_BYTE;
1311 else
1312 spec->type = FORMAT_TYPE_UBYTE;
1313 } else if (spec->qualifier == 'h') {
1314 if (spec->flags & SIGN)
1315 spec->type = FORMAT_TYPE_SHORT;
1316 else
1317 spec->type = FORMAT_TYPE_USHORT;
1318 } else {
1319 if (spec->flags & SIGN)
1320 spec->type = FORMAT_TYPE_INT;
1321 else
1322 spec->type = FORMAT_TYPE_UINT;
1323 }
1324
1325 return ++fmt - start;
1326 }
1327
1328 /**
1329 * vsnprintf - Format a string and place it in a buffer
1330 * @buf: The buffer to place the result into
1331 * @size: The size of the buffer, including the trailing null space
1332 * @fmt: The format string to use
1333 * @args: Arguments for the format string
1334 *
1335 * This function follows C99 vsnprintf, but has some extensions:
1336 * %pS output the name of a text symbol with offset
1337 * %ps output the name of a text symbol without offset
1338 * %pF output the name of a function pointer with its offset
1339 * %pf output the name of a function pointer without its offset
1340 * %pB output the name of a backtrace symbol with its offset
1341 * %pR output the address range in a struct resource with decoded flags
1342 * %pr output the address range in a struct resource with raw flags
1343 * %pM output a 6-byte MAC address with colons
1344 * %pm output a 6-byte MAC address without colons
1345 * %pI4 print an IPv4 address without leading zeros
1346 * %pi4 print an IPv4 address with leading zeros
1347 * %pI6 print an IPv6 address with colons
1348 * %pi6 print an IPv6 address without colons
1349 * %pI6c print an IPv6 address as specified by RFC 5952
1350 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1351 * case.
1352 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1353 * bytes of the input)
1354 * %n is ignored
1355 *
1356 * ** Please update Documentation/printk-formats.txt when making changes **
1357 *
1358 * The return value is the number of characters which would
1359 * be generated for the given input, excluding the trailing
1360 * '\0', as per ISO C99. If you want to have the exact
1361 * number of characters written into @buf as return value
1362 * (not including the trailing '\0'), use vscnprintf(). If the
1363 * return is greater than or equal to @size, the resulting
1364 * string is truncated.
1365 *
1366 * If you're not already dealing with a va_list consider using snprintf().
1367 */
1368 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1369 {
1370 unsigned long long num;
1371 char *str, *end;
1372 struct printf_spec spec = {0};
1373
1374 /* Reject out-of-range values early. Large positive sizes are
1375 used for unknown buffer sizes. */
1376 if (WARN_ON_ONCE((int) size < 0))
1377 return 0;
1378
1379 str = buf;
1380 end = buf + size;
1381
1382 /* Make sure end is always >= buf */
1383 if (end < buf) {
1384 end = ((void *)-1);
1385 size = end - buf;
1386 }
1387
1388 while (*fmt) {
1389 const char *old_fmt = fmt;
1390 int read = format_decode(fmt, &spec);
1391
1392 fmt += read;
1393
1394 switch (spec.type) {
1395 case FORMAT_TYPE_NONE: {
1396 int copy = read;
1397 if (str < end) {
1398 if (copy > end - str)
1399 copy = end - str;
1400 memcpy(str, old_fmt, copy);
1401 }
1402 str += read;
1403 break;
1404 }
1405
1406 case FORMAT_TYPE_WIDTH:
1407 spec.field_width = va_arg(args, int);
1408 break;
1409
1410 case FORMAT_TYPE_PRECISION:
1411 spec.precision = va_arg(args, int);
1412 break;
1413
1414 case FORMAT_TYPE_CHAR: {
1415 char c;
1416
1417 if (!(spec.flags & LEFT)) {
1418 while (--spec.field_width > 0) {
1419 if (str < end)
1420 *str = ' ';
1421 ++str;
1422
1423 }
1424 }
1425 c = (unsigned char) va_arg(args, int);
1426 if (str < end)
1427 *str = c;
1428 ++str;
1429 while (--spec.field_width > 0) {
1430 if (str < end)
1431 *str = ' ';
1432 ++str;
1433 }
1434 break;
1435 }
1436
1437 case FORMAT_TYPE_STR:
1438 str = string(str, end, va_arg(args, char *), spec);
1439 break;
1440
1441 case FORMAT_TYPE_PTR:
1442 str = pointer(fmt+1, str, end, va_arg(args, void *),
1443 spec);
1444 while (isalnum(*fmt))
1445 fmt++;
1446 break;
1447
1448 case FORMAT_TYPE_PERCENT_CHAR:
1449 if (str < end)
1450 *str = '%';
1451 ++str;
1452 break;
1453
1454 case FORMAT_TYPE_INVALID:
1455 if (str < end)
1456 *str = '%';
1457 ++str;
1458 break;
1459
1460 case FORMAT_TYPE_NRCHARS: {
1461 u8 qualifier = spec.qualifier;
1462
1463 if (qualifier == 'l') {
1464 long *ip = va_arg(args, long *);
1465 *ip = (str - buf);
1466 } else if (_tolower(qualifier) == 'z') {
1467 size_t *ip = va_arg(args, size_t *);
1468 *ip = (str - buf);
1469 } else {
1470 int *ip = va_arg(args, int *);
1471 *ip = (str - buf);
1472 }
1473 break;
1474 }
1475
1476 default:
1477 switch (spec.type) {
1478 case FORMAT_TYPE_LONG_LONG:
1479 num = va_arg(args, long long);
1480 break;
1481 case FORMAT_TYPE_ULONG:
1482 num = va_arg(args, unsigned long);
1483 break;
1484 case FORMAT_TYPE_LONG:
1485 num = va_arg(args, long);
1486 break;
1487 case FORMAT_TYPE_SIZE_T:
1488 num = va_arg(args, size_t);
1489 break;
1490 case FORMAT_TYPE_PTRDIFF:
1491 num = va_arg(args, ptrdiff_t);
1492 break;
1493 case FORMAT_TYPE_UBYTE:
1494 num = (unsigned char) va_arg(args, int);
1495 break;
1496 case FORMAT_TYPE_BYTE:
1497 num = (signed char) va_arg(args, int);
1498 break;
1499 case FORMAT_TYPE_USHORT:
1500 num = (unsigned short) va_arg(args, int);
1501 break;
1502 case FORMAT_TYPE_SHORT:
1503 num = (short) va_arg(args, int);
1504 break;
1505 case FORMAT_TYPE_INT:
1506 num = (int) va_arg(args, int);
1507 break;
1508 default:
1509 num = va_arg(args, unsigned int);
1510 }
1511
1512 str = number(str, end, num, spec);
1513 }
1514 }
1515
1516 if (size > 0) {
1517 if (str < end)
1518 *str = '\0';
1519 else
1520 end[-1] = '\0';
1521 }
1522
1523 /* the trailing null byte doesn't count towards the total */
1524 return str-buf;
1525
1526 }
1527 EXPORT_SYMBOL(vsnprintf);
1528
1529 /**
1530 * vscnprintf - Format a string and place it in a buffer
1531 * @buf: The buffer to place the result into
1532 * @size: The size of the buffer, including the trailing null space
1533 * @fmt: The format string to use
1534 * @args: Arguments for the format string
1535 *
1536 * The return value is the number of characters which have been written into
1537 * the @buf not including the trailing '\0'. If @size is == 0 the function
1538 * returns 0.
1539 *
1540 * If you're not already dealing with a va_list consider using scnprintf().
1541 *
1542 * See the vsnprintf() documentation for format string extensions over C99.
1543 */
1544 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1545 {
1546 int i;
1547
1548 i = vsnprintf(buf, size, fmt, args);
1549
1550 if (likely(i < size))
1551 return i;
1552 if (size != 0)
1553 return size - 1;
1554 return 0;
1555 }
1556 EXPORT_SYMBOL(vscnprintf);
1557
1558 /**
1559 * snprintf - Format a string and place it in a buffer
1560 * @buf: The buffer to place the result into
1561 * @size: The size of the buffer, including the trailing null space
1562 * @fmt: The format string to use
1563 * @...: Arguments for the format string
1564 *
1565 * The return value is the number of characters which would be
1566 * generated for the given input, excluding the trailing null,
1567 * as per ISO C99. If the return is greater than or equal to
1568 * @size, the resulting string is truncated.
1569 *
1570 * See the vsnprintf() documentation for format string extensions over C99.
1571 */
1572 int snprintf(char *buf, size_t size, const char *fmt, ...)
1573 {
1574 va_list args;
1575 int i;
1576
1577 va_start(args, fmt);
1578 i = vsnprintf(buf, size, fmt, args);
1579 va_end(args);
1580
1581 return i;
1582 }
1583 EXPORT_SYMBOL(snprintf);
1584
1585 /**
1586 * scnprintf - Format a string and place it in a buffer
1587 * @buf: The buffer to place the result into
1588 * @size: The size of the buffer, including the trailing null space
1589 * @fmt: The format string to use
1590 * @...: Arguments for the format string
1591 *
1592 * The return value is the number of characters written into @buf not including
1593 * the trailing '\0'. If @size is == 0 the function returns 0.
1594 */
1595
1596 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1597 {
1598 va_list args;
1599 int i;
1600
1601 va_start(args, fmt);
1602 i = vscnprintf(buf, size, fmt, args);
1603 va_end(args);
1604
1605 return i;
1606 }
1607 EXPORT_SYMBOL(scnprintf);
1608
1609 /**
1610 * vsprintf - Format a string and place it in a buffer
1611 * @buf: The buffer to place the result into
1612 * @fmt: The format string to use
1613 * @args: Arguments for the format string
1614 *
1615 * The function returns the number of characters written
1616 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1617 * buffer overflows.
1618 *
1619 * If you're not already dealing with a va_list consider using sprintf().
1620 *
1621 * See the vsnprintf() documentation for format string extensions over C99.
1622 */
1623 int vsprintf(char *buf, const char *fmt, va_list args)
1624 {
1625 return vsnprintf(buf, INT_MAX, fmt, args);
1626 }
1627 EXPORT_SYMBOL(vsprintf);
1628
1629 /**
1630 * sprintf - Format a string and place it in a buffer
1631 * @buf: The buffer to place the result into
1632 * @fmt: The format string to use
1633 * @...: Arguments for the format string
1634 *
1635 * The function returns the number of characters written
1636 * into @buf. Use snprintf() or scnprintf() in order to avoid
1637 * buffer overflows.
1638 *
1639 * See the vsnprintf() documentation for format string extensions over C99.
1640 */
1641 int sprintf(char *buf, const char *fmt, ...)
1642 {
1643 va_list args;
1644 int i;
1645
1646 va_start(args, fmt);
1647 i = vsnprintf(buf, INT_MAX, fmt, args);
1648 va_end(args);
1649
1650 return i;
1651 }
1652 EXPORT_SYMBOL(sprintf);
1653
1654 #ifdef CONFIG_BINARY_PRINTF
1655 /*
1656 * bprintf service:
1657 * vbin_printf() - VA arguments to binary data
1658 * bstr_printf() - Binary data to text string
1659 */
1660
1661 /**
1662 * vbin_printf - Parse a format string and place args' binary value in a buffer
1663 * @bin_buf: The buffer to place args' binary value
1664 * @size: The size of the buffer(by words(32bits), not characters)
1665 * @fmt: The format string to use
1666 * @args: Arguments for the format string
1667 *
1668 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1669 * is skiped.
1670 *
1671 * The return value is the number of words(32bits) which would be generated for
1672 * the given input.
1673 *
1674 * NOTE:
1675 * If the return value is greater than @size, the resulting bin_buf is NOT
1676 * valid for bstr_printf().
1677 */
1678 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1679 {
1680 struct printf_spec spec = {0};
1681 char *str, *end;
1682
1683 str = (char *)bin_buf;
1684 end = (char *)(bin_buf + size);
1685
1686 #define save_arg(type) \
1687 do { \
1688 if (sizeof(type) == 8) { \
1689 unsigned long long value; \
1690 str = PTR_ALIGN(str, sizeof(u32)); \
1691 value = va_arg(args, unsigned long long); \
1692 if (str + sizeof(type) <= end) { \
1693 *(u32 *)str = *(u32 *)&value; \
1694 *(u32 *)(str + 4) = *((u32 *)&value + 1); \
1695 } \
1696 } else { \
1697 unsigned long value; \
1698 str = PTR_ALIGN(str, sizeof(type)); \
1699 value = va_arg(args, int); \
1700 if (str + sizeof(type) <= end) \
1701 *(typeof(type) *)str = (type)value; \
1702 } \
1703 str += sizeof(type); \
1704 } while (0)
1705
1706 while (*fmt) {
1707 int read = format_decode(fmt, &spec);
1708
1709 fmt += read;
1710
1711 switch (spec.type) {
1712 case FORMAT_TYPE_NONE:
1713 case FORMAT_TYPE_INVALID:
1714 case FORMAT_TYPE_PERCENT_CHAR:
1715 break;
1716
1717 case FORMAT_TYPE_WIDTH:
1718 case FORMAT_TYPE_PRECISION:
1719 save_arg(int);
1720 break;
1721
1722 case FORMAT_TYPE_CHAR:
1723 save_arg(char);
1724 break;
1725
1726 case FORMAT_TYPE_STR: {
1727 const char *save_str = va_arg(args, char *);
1728 size_t len;
1729
1730 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1731 || (unsigned long)save_str < PAGE_SIZE)
1732 save_str = "(null)";
1733 len = strlen(save_str) + 1;
1734 if (str + len < end)
1735 memcpy(str, save_str, len);
1736 str += len;
1737 break;
1738 }
1739
1740 case FORMAT_TYPE_PTR:
1741 save_arg(void *);
1742 /* skip all alphanumeric pointer suffixes */
1743 while (isalnum(*fmt))
1744 fmt++;
1745 break;
1746
1747 case FORMAT_TYPE_NRCHARS: {
1748 /* skip %n 's argument */
1749 u8 qualifier = spec.qualifier;
1750 void *skip_arg;
1751 if (qualifier == 'l')
1752 skip_arg = va_arg(args, long *);
1753 else if (_tolower(qualifier) == 'z')
1754 skip_arg = va_arg(args, size_t *);
1755 else
1756 skip_arg = va_arg(args, int *);
1757 break;
1758 }
1759
1760 default:
1761 switch (spec.type) {
1762
1763 case FORMAT_TYPE_LONG_LONG:
1764 save_arg(long long);
1765 break;
1766 case FORMAT_TYPE_ULONG:
1767 case FORMAT_TYPE_LONG:
1768 save_arg(unsigned long);
1769 break;
1770 case FORMAT_TYPE_SIZE_T:
1771 save_arg(size_t);
1772 break;
1773 case FORMAT_TYPE_PTRDIFF:
1774 save_arg(ptrdiff_t);
1775 break;
1776 case FORMAT_TYPE_UBYTE:
1777 case FORMAT_TYPE_BYTE:
1778 save_arg(char);
1779 break;
1780 case FORMAT_TYPE_USHORT:
1781 case FORMAT_TYPE_SHORT:
1782 save_arg(short);
1783 break;
1784 default:
1785 save_arg(int);
1786 }
1787 }
1788 }
1789
1790 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1791 #undef save_arg
1792 }
1793 EXPORT_SYMBOL_GPL(vbin_printf);
1794
1795 /**
1796 * bstr_printf - Format a string from binary arguments and place it in a buffer
1797 * @buf: The buffer to place the result into
1798 * @size: The size of the buffer, including the trailing null space
1799 * @fmt: The format string to use
1800 * @bin_buf: Binary arguments for the format string
1801 *
1802 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1803 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1804 * a binary buffer that generated by vbin_printf.
1805 *
1806 * The format follows C99 vsnprintf, but has some extensions:
1807 * see vsnprintf comment for details.
1808 *
1809 * The return value is the number of characters which would
1810 * be generated for the given input, excluding the trailing
1811 * '\0', as per ISO C99. If you want to have the exact
1812 * number of characters written into @buf as return value
1813 * (not including the trailing '\0'), use vscnprintf(). If the
1814 * return is greater than or equal to @size, the resulting
1815 * string is truncated.
1816 */
1817 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1818 {
1819 struct printf_spec spec = {0};
1820 char *str, *end;
1821 const char *args = (const char *)bin_buf;
1822
1823 if (WARN_ON_ONCE((int) size < 0))
1824 return 0;
1825
1826 str = buf;
1827 end = buf + size;
1828
1829 #define get_arg(type) \
1830 ({ \
1831 typeof(type) value; \
1832 if (sizeof(type) == 8) { \
1833 args = PTR_ALIGN(args, sizeof(u32)); \
1834 *(u32 *)&value = *(u32 *)args; \
1835 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
1836 } else { \
1837 args = PTR_ALIGN(args, sizeof(type)); \
1838 value = *(typeof(type) *)args; \
1839 } \
1840 args += sizeof(type); \
1841 value; \
1842 })
1843
1844 /* Make sure end is always >= buf */
1845 if (end < buf) {
1846 end = ((void *)-1);
1847 size = end - buf;
1848 }
1849
1850 while (*fmt) {
1851 const char *old_fmt = fmt;
1852 int read = format_decode(fmt, &spec);
1853
1854 fmt += read;
1855
1856 switch (spec.type) {
1857 case FORMAT_TYPE_NONE: {
1858 int copy = read;
1859 if (str < end) {
1860 if (copy > end - str)
1861 copy = end - str;
1862 memcpy(str, old_fmt, copy);
1863 }
1864 str += read;
1865 break;
1866 }
1867
1868 case FORMAT_TYPE_WIDTH:
1869 spec.field_width = get_arg(int);
1870 break;
1871
1872 case FORMAT_TYPE_PRECISION:
1873 spec.precision = get_arg(int);
1874 break;
1875
1876 case FORMAT_TYPE_CHAR: {
1877 char c;
1878
1879 if (!(spec.flags & LEFT)) {
1880 while (--spec.field_width > 0) {
1881 if (str < end)
1882 *str = ' ';
1883 ++str;
1884 }
1885 }
1886 c = (unsigned char) get_arg(char);
1887 if (str < end)
1888 *str = c;
1889 ++str;
1890 while (--spec.field_width > 0) {
1891 if (str < end)
1892 *str = ' ';
1893 ++str;
1894 }
1895 break;
1896 }
1897
1898 case FORMAT_TYPE_STR: {
1899 const char *str_arg = args;
1900 args += strlen(str_arg) + 1;
1901 str = string(str, end, (char *)str_arg, spec);
1902 break;
1903 }
1904
1905 case FORMAT_TYPE_PTR:
1906 str = pointer(fmt+1, str, end, get_arg(void *), spec);
1907 while (isalnum(*fmt))
1908 fmt++;
1909 break;
1910
1911 case FORMAT_TYPE_PERCENT_CHAR:
1912 case FORMAT_TYPE_INVALID:
1913 if (str < end)
1914 *str = '%';
1915 ++str;
1916 break;
1917
1918 case FORMAT_TYPE_NRCHARS:
1919 /* skip */
1920 break;
1921
1922 default: {
1923 unsigned long long num;
1924
1925 switch (spec.type) {
1926
1927 case FORMAT_TYPE_LONG_LONG:
1928 num = get_arg(long long);
1929 break;
1930 case FORMAT_TYPE_ULONG:
1931 case FORMAT_TYPE_LONG:
1932 num = get_arg(unsigned long);
1933 break;
1934 case FORMAT_TYPE_SIZE_T:
1935 num = get_arg(size_t);
1936 break;
1937 case FORMAT_TYPE_PTRDIFF:
1938 num = get_arg(ptrdiff_t);
1939 break;
1940 case FORMAT_TYPE_UBYTE:
1941 num = get_arg(unsigned char);
1942 break;
1943 case FORMAT_TYPE_BYTE:
1944 num = get_arg(signed char);
1945 break;
1946 case FORMAT_TYPE_USHORT:
1947 num = get_arg(unsigned short);
1948 break;
1949 case FORMAT_TYPE_SHORT:
1950 num = get_arg(short);
1951 break;
1952 case FORMAT_TYPE_UINT:
1953 num = get_arg(unsigned int);
1954 break;
1955 default:
1956 num = get_arg(int);
1957 }
1958
1959 str = number(str, end, num, spec);
1960 } /* default: */
1961 } /* switch(spec.type) */
1962 } /* while(*fmt) */
1963
1964 if (size > 0) {
1965 if (str < end)
1966 *str = '\0';
1967 else
1968 end[-1] = '\0';
1969 }
1970
1971 #undef get_arg
1972
1973 /* the trailing null byte doesn't count towards the total */
1974 return str - buf;
1975 }
1976 EXPORT_SYMBOL_GPL(bstr_printf);
1977
1978 /**
1979 * bprintf - Parse a format string and place args' binary value in a buffer
1980 * @bin_buf: The buffer to place args' binary value
1981 * @size: The size of the buffer(by words(32bits), not characters)
1982 * @fmt: The format string to use
1983 * @...: Arguments for the format string
1984 *
1985 * The function returns the number of words(u32) written
1986 * into @bin_buf.
1987 */
1988 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1989 {
1990 va_list args;
1991 int ret;
1992
1993 va_start(args, fmt);
1994 ret = vbin_printf(bin_buf, size, fmt, args);
1995 va_end(args);
1996
1997 return ret;
1998 }
1999 EXPORT_SYMBOL_GPL(bprintf);
2000
2001 #endif /* CONFIG_BINARY_PRINTF */
2002
2003 /**
2004 * vsscanf - Unformat a buffer into a list of arguments
2005 * @buf: input buffer
2006 * @fmt: format of buffer
2007 * @args: arguments
2008 */
2009 int vsscanf(const char *buf, const char *fmt, va_list args)
2010 {
2011 const char *str = buf;
2012 char *next;
2013 char digit;
2014 int num = 0;
2015 u8 qualifier;
2016 u8 base;
2017 s16 field_width;
2018 bool is_sign;
2019
2020 while (*fmt && *str) {
2021 /* skip any white space in format */
2022 /* white space in format matchs any amount of
2023 * white space, including none, in the input.
2024 */
2025 if (isspace(*fmt)) {
2026 fmt = skip_spaces(++fmt);
2027 str = skip_spaces(str);
2028 }
2029
2030 /* anything that is not a conversion must match exactly */
2031 if (*fmt != '%' && *fmt) {
2032 if (*fmt++ != *str++)
2033 break;
2034 continue;
2035 }
2036
2037 if (!*fmt)
2038 break;
2039 ++fmt;
2040
2041 /* skip this conversion.
2042 * advance both strings to next white space
2043 */
2044 if (*fmt == '*') {
2045 while (!isspace(*fmt) && *fmt != '%' && *fmt)
2046 fmt++;
2047 while (!isspace(*str) && *str)
2048 str++;
2049 continue;
2050 }
2051
2052 /* get field width */
2053 field_width = -1;
2054 if (isdigit(*fmt))
2055 field_width = skip_atoi(&fmt);
2056
2057 /* get conversion qualifier */
2058 qualifier = -1;
2059 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2060 _tolower(*fmt) == 'z') {
2061 qualifier = *fmt++;
2062 if (unlikely(qualifier == *fmt)) {
2063 if (qualifier == 'h') {
2064 qualifier = 'H';
2065 fmt++;
2066 } else if (qualifier == 'l') {
2067 qualifier = 'L';
2068 fmt++;
2069 }
2070 }
2071 }
2072
2073 if (!*fmt || !*str)
2074 break;
2075
2076 base = 10;
2077 is_sign = 0;
2078
2079 switch (*fmt++) {
2080 case 'c':
2081 {
2082 char *s = (char *)va_arg(args, char*);
2083 if (field_width == -1)
2084 field_width = 1;
2085 do {
2086 *s++ = *str++;
2087 } while (--field_width > 0 && *str);
2088 num++;
2089 }
2090 continue;
2091 case 's':
2092 {
2093 char *s = (char *)va_arg(args, char *);
2094 if (field_width == -1)
2095 field_width = SHRT_MAX;
2096 /* first, skip leading white space in buffer */
2097 str = skip_spaces(str);
2098
2099 /* now copy until next white space */
2100 while (*str && !isspace(*str) && field_width--)
2101 *s++ = *str++;
2102 *s = '\0';
2103 num++;
2104 }
2105 continue;
2106 case 'n':
2107 /* return number of characters read so far */
2108 {
2109 int *i = (int *)va_arg(args, int*);
2110 *i = str - buf;
2111 }
2112 continue;
2113 case 'o':
2114 base = 8;
2115 break;
2116 case 'x':
2117 case 'X':
2118 base = 16;
2119 break;
2120 case 'i':
2121 base = 0;
2122 case 'd':
2123 is_sign = 1;
2124 case 'u':
2125 break;
2126 case '%':
2127 /* looking for '%' in str */
2128 if (*str++ != '%')
2129 return num;
2130 continue;
2131 default:
2132 /* invalid format; stop here */
2133 return num;
2134 }
2135
2136 /* have some sort of integer conversion.
2137 * first, skip white space in buffer.
2138 */
2139 str = skip_spaces(str);
2140
2141 digit = *str;
2142 if (is_sign && digit == '-')
2143 digit = *(str + 1);
2144
2145 if (!digit
2146 || (base == 16 && !isxdigit(digit))
2147 || (base == 10 && !isdigit(digit))
2148 || (base == 8 && (!isdigit(digit) || digit > '7'))
2149 || (base == 0 && !isdigit(digit)))
2150 break;
2151
2152 switch (qualifier) {
2153 case 'H': /* that's 'hh' in format */
2154 if (is_sign) {
2155 signed char *s = (signed char *)va_arg(args, signed char *);
2156 *s = (signed char)simple_strtol(str, &next, base);
2157 } else {
2158 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2159 *s = (unsigned char)simple_strtoul(str, &next, base);
2160 }
2161 break;
2162 case 'h':
2163 if (is_sign) {
2164 short *s = (short *)va_arg(args, short *);
2165 *s = (short)simple_strtol(str, &next, base);
2166 } else {
2167 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2168 *s = (unsigned short)simple_strtoul(str, &next, base);
2169 }
2170 break;
2171 case 'l':
2172 if (is_sign) {
2173 long *l = (long *)va_arg(args, long *);
2174 *l = simple_strtol(str, &next, base);
2175 } else {
2176 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2177 *l = simple_strtoul(str, &next, base);
2178 }
2179 break;
2180 case 'L':
2181 if (is_sign) {
2182 long long *l = (long long *)va_arg(args, long long *);
2183 *l = simple_strtoll(str, &next, base);
2184 } else {
2185 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2186 *l = simple_strtoull(str, &next, base);
2187 }
2188 break;
2189 case 'Z':
2190 case 'z':
2191 {
2192 size_t *s = (size_t *)va_arg(args, size_t *);
2193 *s = (size_t)simple_strtoul(str, &next, base);
2194 }
2195 break;
2196 default:
2197 if (is_sign) {
2198 int *i = (int *)va_arg(args, int *);
2199 *i = (int)simple_strtol(str, &next, base);
2200 } else {
2201 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2202 *i = (unsigned int)simple_strtoul(str, &next, base);
2203 }
2204 break;
2205 }
2206 num++;
2207
2208 if (!next)
2209 break;
2210 str = next;
2211 }
2212
2213 /*
2214 * Now we've come all the way through so either the input string or the
2215 * format ended. In the former case, there can be a %n at the current
2216 * position in the format that needs to be filled.
2217 */
2218 if (*fmt == '%' && *(fmt + 1) == 'n') {
2219 int *p = (int *)va_arg(args, int *);
2220 *p = str - buf;
2221 }
2222
2223 return num;
2224 }
2225 EXPORT_SYMBOL(vsscanf);
2226
2227 /**
2228 * sscanf - Unformat a buffer into a list of arguments
2229 * @buf: input buffer
2230 * @fmt: formatting of buffer
2231 * @...: resulting arguments
2232 */
2233 int sscanf(const char *buf, const char *fmt, ...)
2234 {
2235 va_list args;
2236 int i;
2237
2238 va_start(args, fmt);
2239 i = vsscanf(buf, fmt, args);
2240 va_end(args);
2241
2242 return i;
2243 }
2244 EXPORT_SYMBOL(sscanf);