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lib: vsprintf: optimize division by 10000
[deliverable/linux.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 /* See comment in put_dec_full9 for choice of constants */
247 static noinline_for_stack
248 void put_dec_full4(char *buf, unsigned q)
249 {
250 unsigned r;
251 r = (q * 0xccd) >> 15;
252 buf[0] = (q - 10 * r) + '0';
253 q = (r * 0xcd) >> 11;
254 buf[1] = (r - 10 * q) + '0';
255 r = (q * 0xcd) >> 11;
256 buf[2] = (q - 10 * r) + '0';
257 buf[3] = r + '0';
258 }
259
260 /*
261 * Call put_dec_full4 on x % 10000, return x / 10000.
262 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
263 * holds for all x < 1,128,869,999. The largest value this
264 * helper will ever be asked to convert is 1,125,520,955.
265 * (d1 in the put_dec code, assuming n is all-ones).
266 */
267 static
268 unsigned put_dec_helper4(char *buf, unsigned x)
269 {
270 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
271
272 put_dec_full4(buf, x - q * 10000);
273 return q;
274 }
275
276 /* Based on code by Douglas W. Jones found at
277 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
278 * (with permission from the author).
279 * Performs no 64-bit division and hence should be fast on 32-bit machines.
280 */
281 static
282 char *put_dec(char *buf, unsigned long long n)
283 {
284 uint32_t d3, d2, d1, q, h;
285
286 if (n < 100*1000*1000)
287 return put_dec_trunc8(buf, n);
288
289 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
290 h = (n >> 32);
291 d2 = (h ) & 0xffff;
292 d3 = (h >> 16); /* implicit "& 0xffff" */
293
294 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
295 q = put_dec_helper4(buf, q);
296
297 q += 7671 * d3 + 9496 * d2 + 6 * d1;
298 q = put_dec_helper4(buf+4, q);
299
300 q += 4749 * d3 + 42 * d2;
301 q = put_dec_helper4(buf+8, q);
302
303 q += 281 * d3;
304 buf += 12;
305 if (q)
306 buf = put_dec_trunc8(buf, q);
307 else while (buf[-1] == '0')
308 --buf;
309
310 return buf;
311 }
312
313 #endif
314
315 /*
316 * Convert passed number to decimal string.
317 * Returns the length of string. On buffer overflow, returns 0.
318 *
319 * If speed is not important, use snprintf(). It's easy to read the code.
320 */
321 int num_to_str(char *buf, int size, unsigned long long num)
322 {
323 char tmp[sizeof(num) * 3];
324 int idx, len;
325
326 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
327 if (num <= 9) {
328 tmp[0] = '0' + num;
329 len = 1;
330 } else {
331 len = put_dec(tmp, num) - tmp;
332 }
333
334 if (len > size)
335 return 0;
336 for (idx = 0; idx < len; ++idx)
337 buf[idx] = tmp[len - idx - 1];
338 return len;
339 }
340
341 #define ZEROPAD 1 /* pad with zero */
342 #define SIGN 2 /* unsigned/signed long */
343 #define PLUS 4 /* show plus */
344 #define SPACE 8 /* space if plus */
345 #define LEFT 16 /* left justified */
346 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
347 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
348
349 enum format_type {
350 FORMAT_TYPE_NONE, /* Just a string part */
351 FORMAT_TYPE_WIDTH,
352 FORMAT_TYPE_PRECISION,
353 FORMAT_TYPE_CHAR,
354 FORMAT_TYPE_STR,
355 FORMAT_TYPE_PTR,
356 FORMAT_TYPE_PERCENT_CHAR,
357 FORMAT_TYPE_INVALID,
358 FORMAT_TYPE_LONG_LONG,
359 FORMAT_TYPE_ULONG,
360 FORMAT_TYPE_LONG,
361 FORMAT_TYPE_UBYTE,
362 FORMAT_TYPE_BYTE,
363 FORMAT_TYPE_USHORT,
364 FORMAT_TYPE_SHORT,
365 FORMAT_TYPE_UINT,
366 FORMAT_TYPE_INT,
367 FORMAT_TYPE_NRCHARS,
368 FORMAT_TYPE_SIZE_T,
369 FORMAT_TYPE_PTRDIFF
370 };
371
372 struct printf_spec {
373 u8 type; /* format_type enum */
374 u8 flags; /* flags to number() */
375 u8 base; /* number base, 8, 10 or 16 only */
376 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */
377 s16 field_width; /* width of output field */
378 s16 precision; /* # of digits/chars */
379 };
380
381 static noinline_for_stack
382 char *number(char *buf, char *end, unsigned long long num,
383 struct printf_spec spec)
384 {
385 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
386 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
387
388 char tmp[66];
389 char sign;
390 char locase;
391 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
392 int i;
393 bool is_zero = num == 0LL;
394
395 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
396 * produces same digits or (maybe lowercased) letters */
397 locase = (spec.flags & SMALL);
398 if (spec.flags & LEFT)
399 spec.flags &= ~ZEROPAD;
400 sign = 0;
401 if (spec.flags & SIGN) {
402 if ((signed long long)num < 0) {
403 sign = '-';
404 num = -(signed long long)num;
405 spec.field_width--;
406 } else if (spec.flags & PLUS) {
407 sign = '+';
408 spec.field_width--;
409 } else if (spec.flags & SPACE) {
410 sign = ' ';
411 spec.field_width--;
412 }
413 }
414 if (need_pfx) {
415 if (spec.base == 16)
416 spec.field_width -= 2;
417 else if (!is_zero)
418 spec.field_width--;
419 }
420
421 /* generate full string in tmp[], in reverse order */
422 i = 0;
423 if (num < spec.base)
424 tmp[i++] = digits[num] | locase;
425 /* Generic code, for any base:
426 else do {
427 tmp[i++] = (digits[do_div(num,base)] | locase);
428 } while (num != 0);
429 */
430 else if (spec.base != 10) { /* 8 or 16 */
431 int mask = spec.base - 1;
432 int shift = 3;
433
434 if (spec.base == 16)
435 shift = 4;
436 do {
437 tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
438 num >>= shift;
439 } while (num);
440 } else { /* base 10 */
441 i = put_dec(tmp, num) - tmp;
442 }
443
444 /* printing 100 using %2d gives "100", not "00" */
445 if (i > spec.precision)
446 spec.precision = i;
447 /* leading space padding */
448 spec.field_width -= spec.precision;
449 if (!(spec.flags & (ZEROPAD+LEFT))) {
450 while (--spec.field_width >= 0) {
451 if (buf < end)
452 *buf = ' ';
453 ++buf;
454 }
455 }
456 /* sign */
457 if (sign) {
458 if (buf < end)
459 *buf = sign;
460 ++buf;
461 }
462 /* "0x" / "0" prefix */
463 if (need_pfx) {
464 if (spec.base == 16 || !is_zero) {
465 if (buf < end)
466 *buf = '0';
467 ++buf;
468 }
469 if (spec.base == 16) {
470 if (buf < end)
471 *buf = ('X' | locase);
472 ++buf;
473 }
474 }
475 /* zero or space padding */
476 if (!(spec.flags & LEFT)) {
477 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
478 while (--spec.field_width >= 0) {
479 if (buf < end)
480 *buf = c;
481 ++buf;
482 }
483 }
484 /* hmm even more zero padding? */
485 while (i <= --spec.precision) {
486 if (buf < end)
487 *buf = '0';
488 ++buf;
489 }
490 /* actual digits of result */
491 while (--i >= 0) {
492 if (buf < end)
493 *buf = tmp[i];
494 ++buf;
495 }
496 /* trailing space padding */
497 while (--spec.field_width >= 0) {
498 if (buf < end)
499 *buf = ' ';
500 ++buf;
501 }
502
503 return buf;
504 }
505
506 static noinline_for_stack
507 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
508 {
509 int len, i;
510
511 if ((unsigned long)s < PAGE_SIZE)
512 s = "(null)";
513
514 len = strnlen(s, spec.precision);
515
516 if (!(spec.flags & LEFT)) {
517 while (len < spec.field_width--) {
518 if (buf < end)
519 *buf = ' ';
520 ++buf;
521 }
522 }
523 for (i = 0; i < len; ++i) {
524 if (buf < end)
525 *buf = *s;
526 ++buf; ++s;
527 }
528 while (len < spec.field_width--) {
529 if (buf < end)
530 *buf = ' ';
531 ++buf;
532 }
533
534 return buf;
535 }
536
537 static noinline_for_stack
538 char *symbol_string(char *buf, char *end, void *ptr,
539 struct printf_spec spec, char ext)
540 {
541 unsigned long value = (unsigned long) ptr;
542 #ifdef CONFIG_KALLSYMS
543 char sym[KSYM_SYMBOL_LEN];
544 if (ext == 'B')
545 sprint_backtrace(sym, value);
546 else if (ext != 'f' && ext != 's')
547 sprint_symbol(sym, value);
548 else
549 sprint_symbol_no_offset(sym, value);
550
551 return string(buf, end, sym, spec);
552 #else
553 spec.field_width = 2 * sizeof(void *);
554 spec.flags |= SPECIAL | SMALL | ZEROPAD;
555 spec.base = 16;
556
557 return number(buf, end, value, spec);
558 #endif
559 }
560
561 static noinline_for_stack
562 char *resource_string(char *buf, char *end, struct resource *res,
563 struct printf_spec spec, const char *fmt)
564 {
565 #ifndef IO_RSRC_PRINTK_SIZE
566 #define IO_RSRC_PRINTK_SIZE 6
567 #endif
568
569 #ifndef MEM_RSRC_PRINTK_SIZE
570 #define MEM_RSRC_PRINTK_SIZE 10
571 #endif
572 static const struct printf_spec io_spec = {
573 .base = 16,
574 .field_width = IO_RSRC_PRINTK_SIZE,
575 .precision = -1,
576 .flags = SPECIAL | SMALL | ZEROPAD,
577 };
578 static const struct printf_spec mem_spec = {
579 .base = 16,
580 .field_width = MEM_RSRC_PRINTK_SIZE,
581 .precision = -1,
582 .flags = SPECIAL | SMALL | ZEROPAD,
583 };
584 static const struct printf_spec bus_spec = {
585 .base = 16,
586 .field_width = 2,
587 .precision = -1,
588 .flags = SMALL | ZEROPAD,
589 };
590 static const struct printf_spec dec_spec = {
591 .base = 10,
592 .precision = -1,
593 .flags = 0,
594 };
595 static const struct printf_spec str_spec = {
596 .field_width = -1,
597 .precision = 10,
598 .flags = LEFT,
599 };
600 static const struct printf_spec flag_spec = {
601 .base = 16,
602 .precision = -1,
603 .flags = SPECIAL | SMALL,
604 };
605
606 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
607 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
608 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
609 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
610 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
611 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
612 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
613 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
614
615 char *p = sym, *pend = sym + sizeof(sym);
616 int decode = (fmt[0] == 'R') ? 1 : 0;
617 const struct printf_spec *specp;
618
619 *p++ = '[';
620 if (res->flags & IORESOURCE_IO) {
621 p = string(p, pend, "io ", str_spec);
622 specp = &io_spec;
623 } else if (res->flags & IORESOURCE_MEM) {
624 p = string(p, pend, "mem ", str_spec);
625 specp = &mem_spec;
626 } else if (res->flags & IORESOURCE_IRQ) {
627 p = string(p, pend, "irq ", str_spec);
628 specp = &dec_spec;
629 } else if (res->flags & IORESOURCE_DMA) {
630 p = string(p, pend, "dma ", str_spec);
631 specp = &dec_spec;
632 } else if (res->flags & IORESOURCE_BUS) {
633 p = string(p, pend, "bus ", str_spec);
634 specp = &bus_spec;
635 } else {
636 p = string(p, pend, "??? ", str_spec);
637 specp = &mem_spec;
638 decode = 0;
639 }
640 p = number(p, pend, res->start, *specp);
641 if (res->start != res->end) {
642 *p++ = '-';
643 p = number(p, pend, res->end, *specp);
644 }
645 if (decode) {
646 if (res->flags & IORESOURCE_MEM_64)
647 p = string(p, pend, " 64bit", str_spec);
648 if (res->flags & IORESOURCE_PREFETCH)
649 p = string(p, pend, " pref", str_spec);
650 if (res->flags & IORESOURCE_WINDOW)
651 p = string(p, pend, " window", str_spec);
652 if (res->flags & IORESOURCE_DISABLED)
653 p = string(p, pend, " disabled", str_spec);
654 } else {
655 p = string(p, pend, " flags ", str_spec);
656 p = number(p, pend, res->flags, flag_spec);
657 }
658 *p++ = ']';
659 *p = '\0';
660
661 return string(buf, end, sym, spec);
662 }
663
664 static noinline_for_stack
665 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
666 const char *fmt)
667 {
668 int i, len = 1; /* if we pass '%ph[CDN]', field witdh remains
669 negative value, fallback to the default */
670 char separator;
671
672 if (spec.field_width == 0)
673 /* nothing to print */
674 return buf;
675
676 if (ZERO_OR_NULL_PTR(addr))
677 /* NULL pointer */
678 return string(buf, end, NULL, spec);
679
680 switch (fmt[1]) {
681 case 'C':
682 separator = ':';
683 break;
684 case 'D':
685 separator = '-';
686 break;
687 case 'N':
688 separator = 0;
689 break;
690 default:
691 separator = ' ';
692 break;
693 }
694
695 if (spec.field_width > 0)
696 len = min_t(int, spec.field_width, 64);
697
698 for (i = 0; i < len && buf < end - 1; i++) {
699 buf = hex_byte_pack(buf, addr[i]);
700
701 if (buf < end && separator && i != len - 1)
702 *buf++ = separator;
703 }
704
705 return buf;
706 }
707
708 static noinline_for_stack
709 char *mac_address_string(char *buf, char *end, u8 *addr,
710 struct printf_spec spec, const char *fmt)
711 {
712 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
713 char *p = mac_addr;
714 int i;
715 char separator;
716 bool reversed = false;
717
718 switch (fmt[1]) {
719 case 'F':
720 separator = '-';
721 break;
722
723 case 'R':
724 reversed = true;
725 /* fall through */
726
727 default:
728 separator = ':';
729 break;
730 }
731
732 for (i = 0; i < 6; i++) {
733 if (reversed)
734 p = hex_byte_pack(p, addr[5 - i]);
735 else
736 p = hex_byte_pack(p, addr[i]);
737
738 if (fmt[0] == 'M' && i != 5)
739 *p++ = separator;
740 }
741 *p = '\0';
742
743 return string(buf, end, mac_addr, spec);
744 }
745
746 static noinline_for_stack
747 char *ip4_string(char *p, const u8 *addr, const char *fmt)
748 {
749 int i;
750 bool leading_zeros = (fmt[0] == 'i');
751 int index;
752 int step;
753
754 switch (fmt[2]) {
755 case 'h':
756 #ifdef __BIG_ENDIAN
757 index = 0;
758 step = 1;
759 #else
760 index = 3;
761 step = -1;
762 #endif
763 break;
764 case 'l':
765 index = 3;
766 step = -1;
767 break;
768 case 'n':
769 case 'b':
770 default:
771 index = 0;
772 step = 1;
773 break;
774 }
775 for (i = 0; i < 4; i++) {
776 char temp[3]; /* hold each IP quad in reverse order */
777 int digits = put_dec_trunc8(temp, addr[index]) - temp;
778 if (leading_zeros) {
779 if (digits < 3)
780 *p++ = '0';
781 if (digits < 2)
782 *p++ = '0';
783 }
784 /* reverse the digits in the quad */
785 while (digits--)
786 *p++ = temp[digits];
787 if (i < 3)
788 *p++ = '.';
789 index += step;
790 }
791 *p = '\0';
792
793 return p;
794 }
795
796 static noinline_for_stack
797 char *ip6_compressed_string(char *p, const char *addr)
798 {
799 int i, j, range;
800 unsigned char zerolength[8];
801 int longest = 1;
802 int colonpos = -1;
803 u16 word;
804 u8 hi, lo;
805 bool needcolon = false;
806 bool useIPv4;
807 struct in6_addr in6;
808
809 memcpy(&in6, addr, sizeof(struct in6_addr));
810
811 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
812
813 memset(zerolength, 0, sizeof(zerolength));
814
815 if (useIPv4)
816 range = 6;
817 else
818 range = 8;
819
820 /* find position of longest 0 run */
821 for (i = 0; i < range; i++) {
822 for (j = i; j < range; j++) {
823 if (in6.s6_addr16[j] != 0)
824 break;
825 zerolength[i]++;
826 }
827 }
828 for (i = 0; i < range; i++) {
829 if (zerolength[i] > longest) {
830 longest = zerolength[i];
831 colonpos = i;
832 }
833 }
834 if (longest == 1) /* don't compress a single 0 */
835 colonpos = -1;
836
837 /* emit address */
838 for (i = 0; i < range; i++) {
839 if (i == colonpos) {
840 if (needcolon || i == 0)
841 *p++ = ':';
842 *p++ = ':';
843 needcolon = false;
844 i += longest - 1;
845 continue;
846 }
847 if (needcolon) {
848 *p++ = ':';
849 needcolon = false;
850 }
851 /* hex u16 without leading 0s */
852 word = ntohs(in6.s6_addr16[i]);
853 hi = word >> 8;
854 lo = word & 0xff;
855 if (hi) {
856 if (hi > 0x0f)
857 p = hex_byte_pack(p, hi);
858 else
859 *p++ = hex_asc_lo(hi);
860 p = hex_byte_pack(p, lo);
861 }
862 else if (lo > 0x0f)
863 p = hex_byte_pack(p, lo);
864 else
865 *p++ = hex_asc_lo(lo);
866 needcolon = true;
867 }
868
869 if (useIPv4) {
870 if (needcolon)
871 *p++ = ':';
872 p = ip4_string(p, &in6.s6_addr[12], "I4");
873 }
874 *p = '\0';
875
876 return p;
877 }
878
879 static noinline_for_stack
880 char *ip6_string(char *p, const char *addr, const char *fmt)
881 {
882 int i;
883
884 for (i = 0; i < 8; i++) {
885 p = hex_byte_pack(p, *addr++);
886 p = hex_byte_pack(p, *addr++);
887 if (fmt[0] == 'I' && i != 7)
888 *p++ = ':';
889 }
890 *p = '\0';
891
892 return p;
893 }
894
895 static noinline_for_stack
896 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
897 struct printf_spec spec, const char *fmt)
898 {
899 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
900
901 if (fmt[0] == 'I' && fmt[2] == 'c')
902 ip6_compressed_string(ip6_addr, addr);
903 else
904 ip6_string(ip6_addr, addr, fmt);
905
906 return string(buf, end, ip6_addr, spec);
907 }
908
909 static noinline_for_stack
910 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
911 struct printf_spec spec, const char *fmt)
912 {
913 char ip4_addr[sizeof("255.255.255.255")];
914
915 ip4_string(ip4_addr, addr, fmt);
916
917 return string(buf, end, ip4_addr, spec);
918 }
919
920 static noinline_for_stack
921 char *uuid_string(char *buf, char *end, const u8 *addr,
922 struct printf_spec spec, const char *fmt)
923 {
924 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
925 char *p = uuid;
926 int i;
927 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
928 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
929 const u8 *index = be;
930 bool uc = false;
931
932 switch (*(++fmt)) {
933 case 'L':
934 uc = true; /* fall-through */
935 case 'l':
936 index = le;
937 break;
938 case 'B':
939 uc = true;
940 break;
941 }
942
943 for (i = 0; i < 16; i++) {
944 p = hex_byte_pack(p, addr[index[i]]);
945 switch (i) {
946 case 3:
947 case 5:
948 case 7:
949 case 9:
950 *p++ = '-';
951 break;
952 }
953 }
954
955 *p = 0;
956
957 if (uc) {
958 p = uuid;
959 do {
960 *p = toupper(*p);
961 } while (*(++p));
962 }
963
964 return string(buf, end, uuid, spec);
965 }
966
967 static
968 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
969 struct printf_spec spec)
970 {
971 spec.flags |= SPECIAL | SMALL | ZEROPAD;
972 if (spec.field_width == -1)
973 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
974 spec.base = 16;
975
976 return number(buf, end, *(const netdev_features_t *)addr, spec);
977 }
978
979 int kptr_restrict __read_mostly;
980
981 /*
982 * Show a '%p' thing. A kernel extension is that the '%p' is followed
983 * by an extra set of alphanumeric characters that are extended format
984 * specifiers.
985 *
986 * Right now we handle:
987 *
988 * - 'F' For symbolic function descriptor pointers with offset
989 * - 'f' For simple symbolic function names without offset
990 * - 'S' For symbolic direct pointers with offset
991 * - 's' For symbolic direct pointers without offset
992 * - 'B' For backtraced symbolic direct pointers with offset
993 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
994 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
995 * - 'M' For a 6-byte MAC address, it prints the address in the
996 * usual colon-separated hex notation
997 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
998 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
999 * with a dash-separated hex notation
1000 * - '[mM]R For a 6-byte MAC address, Reverse order (Bluetooth)
1001 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1002 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1003 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
1004 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1005 * IPv6 omits the colons (01020304...0f)
1006 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1007 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
1008 * - 'I6c' for IPv6 addresses printed as specified by
1009 * http://tools.ietf.org/html/rfc5952
1010 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1011 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1012 * Options for %pU are:
1013 * b big endian lower case hex (default)
1014 * B big endian UPPER case hex
1015 * l little endian lower case hex
1016 * L little endian UPPER case hex
1017 * big endian output byte order is:
1018 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1019 * little endian output byte order is:
1020 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1021 * - 'V' For a struct va_format which contains a format string * and va_list *,
1022 * call vsnprintf(->format, *->va_list).
1023 * Implements a "recursive vsnprintf".
1024 * Do not use this feature without some mechanism to verify the
1025 * correctness of the format string and va_list arguments.
1026 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1027 * - 'NF' For a netdev_features_t
1028 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1029 * a certain separator (' ' by default):
1030 * C colon
1031 * D dash
1032 * N no separator
1033 * The maximum supported length is 64 bytes of the input. Consider
1034 * to use print_hex_dump() for the larger input.
1035 *
1036 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1037 * function pointers are really function descriptors, which contain a
1038 * pointer to the real address.
1039 */
1040 static noinline_for_stack
1041 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1042 struct printf_spec spec)
1043 {
1044 int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1045
1046 if (!ptr && *fmt != 'K') {
1047 /*
1048 * Print (null) with the same width as a pointer so it makes
1049 * tabular output look nice.
1050 */
1051 if (spec.field_width == -1)
1052 spec.field_width = default_width;
1053 return string(buf, end, "(null)", spec);
1054 }
1055
1056 switch (*fmt) {
1057 case 'F':
1058 case 'f':
1059 ptr = dereference_function_descriptor(ptr);
1060 /* Fallthrough */
1061 case 'S':
1062 case 's':
1063 case 'B':
1064 return symbol_string(buf, end, ptr, spec, *fmt);
1065 case 'R':
1066 case 'r':
1067 return resource_string(buf, end, ptr, spec, fmt);
1068 case 'h':
1069 return hex_string(buf, end, ptr, spec, fmt);
1070 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1071 case 'm': /* Contiguous: 000102030405 */
1072 /* [mM]F (FDDI) */
1073 /* [mM]R (Reverse order; Bluetooth) */
1074 return mac_address_string(buf, end, ptr, spec, fmt);
1075 case 'I': /* Formatted IP supported
1076 * 4: 1.2.3.4
1077 * 6: 0001:0203:...:0708
1078 * 6c: 1::708 or 1::1.2.3.4
1079 */
1080 case 'i': /* Contiguous:
1081 * 4: 001.002.003.004
1082 * 6: 000102...0f
1083 */
1084 switch (fmt[1]) {
1085 case '6':
1086 return ip6_addr_string(buf, end, ptr, spec, fmt);
1087 case '4':
1088 return ip4_addr_string(buf, end, ptr, spec, fmt);
1089 }
1090 break;
1091 case 'U':
1092 return uuid_string(buf, end, ptr, spec, fmt);
1093 case 'V':
1094 {
1095 va_list va;
1096
1097 va_copy(va, *((struct va_format *)ptr)->va);
1098 buf += vsnprintf(buf, end > buf ? end - buf : 0,
1099 ((struct va_format *)ptr)->fmt, va);
1100 va_end(va);
1101 return buf;
1102 }
1103 case 'K':
1104 /*
1105 * %pK cannot be used in IRQ context because its test
1106 * for CAP_SYSLOG would be meaningless.
1107 */
1108 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1109 in_nmi())) {
1110 if (spec.field_width == -1)
1111 spec.field_width = default_width;
1112 return string(buf, end, "pK-error", spec);
1113 }
1114 if (!((kptr_restrict == 0) ||
1115 (kptr_restrict == 1 &&
1116 has_capability_noaudit(current, CAP_SYSLOG))))
1117 ptr = NULL;
1118 break;
1119 case 'N':
1120 switch (fmt[1]) {
1121 case 'F':
1122 return netdev_feature_string(buf, end, ptr, spec);
1123 }
1124 break;
1125 }
1126 spec.flags |= SMALL;
1127 if (spec.field_width == -1) {
1128 spec.field_width = default_width;
1129 spec.flags |= ZEROPAD;
1130 }
1131 spec.base = 16;
1132
1133 return number(buf, end, (unsigned long) ptr, spec);
1134 }
1135
1136 /*
1137 * Helper function to decode printf style format.
1138 * Each call decode a token from the format and return the
1139 * number of characters read (or likely the delta where it wants
1140 * to go on the next call).
1141 * The decoded token is returned through the parameters
1142 *
1143 * 'h', 'l', or 'L' for integer fields
1144 * 'z' support added 23/7/1999 S.H.
1145 * 'z' changed to 'Z' --davidm 1/25/99
1146 * 't' added for ptrdiff_t
1147 *
1148 * @fmt: the format string
1149 * @type of the token returned
1150 * @flags: various flags such as +, -, # tokens..
1151 * @field_width: overwritten width
1152 * @base: base of the number (octal, hex, ...)
1153 * @precision: precision of a number
1154 * @qualifier: qualifier of a number (long, size_t, ...)
1155 */
1156 static noinline_for_stack
1157 int format_decode(const char *fmt, struct printf_spec *spec)
1158 {
1159 const char *start = fmt;
1160
1161 /* we finished early by reading the field width */
1162 if (spec->type == FORMAT_TYPE_WIDTH) {
1163 if (spec->field_width < 0) {
1164 spec->field_width = -spec->field_width;
1165 spec->flags |= LEFT;
1166 }
1167 spec->type = FORMAT_TYPE_NONE;
1168 goto precision;
1169 }
1170
1171 /* we finished early by reading the precision */
1172 if (spec->type == FORMAT_TYPE_PRECISION) {
1173 if (spec->precision < 0)
1174 spec->precision = 0;
1175
1176 spec->type = FORMAT_TYPE_NONE;
1177 goto qualifier;
1178 }
1179
1180 /* By default */
1181 spec->type = FORMAT_TYPE_NONE;
1182
1183 for (; *fmt ; ++fmt) {
1184 if (*fmt == '%')
1185 break;
1186 }
1187
1188 /* Return the current non-format string */
1189 if (fmt != start || !*fmt)
1190 return fmt - start;
1191
1192 /* Process flags */
1193 spec->flags = 0;
1194
1195 while (1) { /* this also skips first '%' */
1196 bool found = true;
1197
1198 ++fmt;
1199
1200 switch (*fmt) {
1201 case '-': spec->flags |= LEFT; break;
1202 case '+': spec->flags |= PLUS; break;
1203 case ' ': spec->flags |= SPACE; break;
1204 case '#': spec->flags |= SPECIAL; break;
1205 case '0': spec->flags |= ZEROPAD; break;
1206 default: found = false;
1207 }
1208
1209 if (!found)
1210 break;
1211 }
1212
1213 /* get field width */
1214 spec->field_width = -1;
1215
1216 if (isdigit(*fmt))
1217 spec->field_width = skip_atoi(&fmt);
1218 else if (*fmt == '*') {
1219 /* it's the next argument */
1220 spec->type = FORMAT_TYPE_WIDTH;
1221 return ++fmt - start;
1222 }
1223
1224 precision:
1225 /* get the precision */
1226 spec->precision = -1;
1227 if (*fmt == '.') {
1228 ++fmt;
1229 if (isdigit(*fmt)) {
1230 spec->precision = skip_atoi(&fmt);
1231 if (spec->precision < 0)
1232 spec->precision = 0;
1233 } else if (*fmt == '*') {
1234 /* it's the next argument */
1235 spec->type = FORMAT_TYPE_PRECISION;
1236 return ++fmt - start;
1237 }
1238 }
1239
1240 qualifier:
1241 /* get the conversion qualifier */
1242 spec->qualifier = -1;
1243 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1244 _tolower(*fmt) == 'z' || *fmt == 't') {
1245 spec->qualifier = *fmt++;
1246 if (unlikely(spec->qualifier == *fmt)) {
1247 if (spec->qualifier == 'l') {
1248 spec->qualifier = 'L';
1249 ++fmt;
1250 } else if (spec->qualifier == 'h') {
1251 spec->qualifier = 'H';
1252 ++fmt;
1253 }
1254 }
1255 }
1256
1257 /* default base */
1258 spec->base = 10;
1259 switch (*fmt) {
1260 case 'c':
1261 spec->type = FORMAT_TYPE_CHAR;
1262 return ++fmt - start;
1263
1264 case 's':
1265 spec->type = FORMAT_TYPE_STR;
1266 return ++fmt - start;
1267
1268 case 'p':
1269 spec->type = FORMAT_TYPE_PTR;
1270 return fmt - start;
1271 /* skip alnum */
1272
1273 case 'n':
1274 spec->type = FORMAT_TYPE_NRCHARS;
1275 return ++fmt - start;
1276
1277 case '%':
1278 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1279 return ++fmt - start;
1280
1281 /* integer number formats - set up the flags and "break" */
1282 case 'o':
1283 spec->base = 8;
1284 break;
1285
1286 case 'x':
1287 spec->flags |= SMALL;
1288
1289 case 'X':
1290 spec->base = 16;
1291 break;
1292
1293 case 'd':
1294 case 'i':
1295 spec->flags |= SIGN;
1296 case 'u':
1297 break;
1298
1299 default:
1300 spec->type = FORMAT_TYPE_INVALID;
1301 return fmt - start;
1302 }
1303
1304 if (spec->qualifier == 'L')
1305 spec->type = FORMAT_TYPE_LONG_LONG;
1306 else if (spec->qualifier == 'l') {
1307 if (spec->flags & SIGN)
1308 spec->type = FORMAT_TYPE_LONG;
1309 else
1310 spec->type = FORMAT_TYPE_ULONG;
1311 } else if (_tolower(spec->qualifier) == 'z') {
1312 spec->type = FORMAT_TYPE_SIZE_T;
1313 } else if (spec->qualifier == 't') {
1314 spec->type = FORMAT_TYPE_PTRDIFF;
1315 } else if (spec->qualifier == 'H') {
1316 if (spec->flags & SIGN)
1317 spec->type = FORMAT_TYPE_BYTE;
1318 else
1319 spec->type = FORMAT_TYPE_UBYTE;
1320 } else if (spec->qualifier == 'h') {
1321 if (spec->flags & SIGN)
1322 spec->type = FORMAT_TYPE_SHORT;
1323 else
1324 spec->type = FORMAT_TYPE_USHORT;
1325 } else {
1326 if (spec->flags & SIGN)
1327 spec->type = FORMAT_TYPE_INT;
1328 else
1329 spec->type = FORMAT_TYPE_UINT;
1330 }
1331
1332 return ++fmt - start;
1333 }
1334
1335 /**
1336 * vsnprintf - Format a string and place it in a buffer
1337 * @buf: The buffer to place the result into
1338 * @size: The size of the buffer, including the trailing null space
1339 * @fmt: The format string to use
1340 * @args: Arguments for the format string
1341 *
1342 * This function follows C99 vsnprintf, but has some extensions:
1343 * %pS output the name of a text symbol with offset
1344 * %ps output the name of a text symbol without offset
1345 * %pF output the name of a function pointer with its offset
1346 * %pf output the name of a function pointer without its offset
1347 * %pB output the name of a backtrace symbol with its offset
1348 * %pR output the address range in a struct resource with decoded flags
1349 * %pr output the address range in a struct resource with raw flags
1350 * %pM output a 6-byte MAC address with colons
1351 * %pm output a 6-byte MAC address without colons
1352 * %pI4 print an IPv4 address without leading zeros
1353 * %pi4 print an IPv4 address with leading zeros
1354 * %pI6 print an IPv6 address with colons
1355 * %pi6 print an IPv6 address without colons
1356 * %pI6c print an IPv6 address as specified by RFC 5952
1357 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1358 * case.
1359 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1360 * bytes of the input)
1361 * %n is ignored
1362 *
1363 * ** Please update Documentation/printk-formats.txt when making changes **
1364 *
1365 * The return value is the number of characters which would
1366 * be generated for the given input, excluding the trailing
1367 * '\0', as per ISO C99. If you want to have the exact
1368 * number of characters written into @buf as return value
1369 * (not including the trailing '\0'), use vscnprintf(). If the
1370 * return is greater than or equal to @size, the resulting
1371 * string is truncated.
1372 *
1373 * If you're not already dealing with a va_list consider using snprintf().
1374 */
1375 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1376 {
1377 unsigned long long num;
1378 char *str, *end;
1379 struct printf_spec spec = {0};
1380
1381 /* Reject out-of-range values early. Large positive sizes are
1382 used for unknown buffer sizes. */
1383 if (WARN_ON_ONCE((int) size < 0))
1384 return 0;
1385
1386 str = buf;
1387 end = buf + size;
1388
1389 /* Make sure end is always >= buf */
1390 if (end < buf) {
1391 end = ((void *)-1);
1392 size = end - buf;
1393 }
1394
1395 while (*fmt) {
1396 const char *old_fmt = fmt;
1397 int read = format_decode(fmt, &spec);
1398
1399 fmt += read;
1400
1401 switch (spec.type) {
1402 case FORMAT_TYPE_NONE: {
1403 int copy = read;
1404 if (str < end) {
1405 if (copy > end - str)
1406 copy = end - str;
1407 memcpy(str, old_fmt, copy);
1408 }
1409 str += read;
1410 break;
1411 }
1412
1413 case FORMAT_TYPE_WIDTH:
1414 spec.field_width = va_arg(args, int);
1415 break;
1416
1417 case FORMAT_TYPE_PRECISION:
1418 spec.precision = va_arg(args, int);
1419 break;
1420
1421 case FORMAT_TYPE_CHAR: {
1422 char c;
1423
1424 if (!(spec.flags & LEFT)) {
1425 while (--spec.field_width > 0) {
1426 if (str < end)
1427 *str = ' ';
1428 ++str;
1429
1430 }
1431 }
1432 c = (unsigned char) va_arg(args, int);
1433 if (str < end)
1434 *str = c;
1435 ++str;
1436 while (--spec.field_width > 0) {
1437 if (str < end)
1438 *str = ' ';
1439 ++str;
1440 }
1441 break;
1442 }
1443
1444 case FORMAT_TYPE_STR:
1445 str = string(str, end, va_arg(args, char *), spec);
1446 break;
1447
1448 case FORMAT_TYPE_PTR:
1449 str = pointer(fmt+1, str, end, va_arg(args, void *),
1450 spec);
1451 while (isalnum(*fmt))
1452 fmt++;
1453 break;
1454
1455 case FORMAT_TYPE_PERCENT_CHAR:
1456 if (str < end)
1457 *str = '%';
1458 ++str;
1459 break;
1460
1461 case FORMAT_TYPE_INVALID:
1462 if (str < end)
1463 *str = '%';
1464 ++str;
1465 break;
1466
1467 case FORMAT_TYPE_NRCHARS: {
1468 u8 qualifier = spec.qualifier;
1469
1470 if (qualifier == 'l') {
1471 long *ip = va_arg(args, long *);
1472 *ip = (str - buf);
1473 } else if (_tolower(qualifier) == 'z') {
1474 size_t *ip = va_arg(args, size_t *);
1475 *ip = (str - buf);
1476 } else {
1477 int *ip = va_arg(args, int *);
1478 *ip = (str - buf);
1479 }
1480 break;
1481 }
1482
1483 default:
1484 switch (spec.type) {
1485 case FORMAT_TYPE_LONG_LONG:
1486 num = va_arg(args, long long);
1487 break;
1488 case FORMAT_TYPE_ULONG:
1489 num = va_arg(args, unsigned long);
1490 break;
1491 case FORMAT_TYPE_LONG:
1492 num = va_arg(args, long);
1493 break;
1494 case FORMAT_TYPE_SIZE_T:
1495 num = va_arg(args, size_t);
1496 break;
1497 case FORMAT_TYPE_PTRDIFF:
1498 num = va_arg(args, ptrdiff_t);
1499 break;
1500 case FORMAT_TYPE_UBYTE:
1501 num = (unsigned char) va_arg(args, int);
1502 break;
1503 case FORMAT_TYPE_BYTE:
1504 num = (signed char) va_arg(args, int);
1505 break;
1506 case FORMAT_TYPE_USHORT:
1507 num = (unsigned short) va_arg(args, int);
1508 break;
1509 case FORMAT_TYPE_SHORT:
1510 num = (short) va_arg(args, int);
1511 break;
1512 case FORMAT_TYPE_INT:
1513 num = (int) va_arg(args, int);
1514 break;
1515 default:
1516 num = va_arg(args, unsigned int);
1517 }
1518
1519 str = number(str, end, num, spec);
1520 }
1521 }
1522
1523 if (size > 0) {
1524 if (str < end)
1525 *str = '\0';
1526 else
1527 end[-1] = '\0';
1528 }
1529
1530 /* the trailing null byte doesn't count towards the total */
1531 return str-buf;
1532
1533 }
1534 EXPORT_SYMBOL(vsnprintf);
1535
1536 /**
1537 * vscnprintf - Format a string and place it in a buffer
1538 * @buf: The buffer to place the result into
1539 * @size: The size of the buffer, including the trailing null space
1540 * @fmt: The format string to use
1541 * @args: Arguments for the format string
1542 *
1543 * The return value is the number of characters which have been written into
1544 * the @buf not including the trailing '\0'. If @size is == 0 the function
1545 * returns 0.
1546 *
1547 * If you're not already dealing with a va_list consider using scnprintf().
1548 *
1549 * See the vsnprintf() documentation for format string extensions over C99.
1550 */
1551 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1552 {
1553 int i;
1554
1555 i = vsnprintf(buf, size, fmt, args);
1556
1557 if (likely(i < size))
1558 return i;
1559 if (size != 0)
1560 return size - 1;
1561 return 0;
1562 }
1563 EXPORT_SYMBOL(vscnprintf);
1564
1565 /**
1566 * snprintf - Format a string and place it in a buffer
1567 * @buf: The buffer to place the result into
1568 * @size: The size of the buffer, including the trailing null space
1569 * @fmt: The format string to use
1570 * @...: Arguments for the format string
1571 *
1572 * The return value is the number of characters which would be
1573 * generated for the given input, excluding the trailing null,
1574 * as per ISO C99. If the return is greater than or equal to
1575 * @size, the resulting string is truncated.
1576 *
1577 * See the vsnprintf() documentation for format string extensions over C99.
1578 */
1579 int snprintf(char *buf, size_t size, const char *fmt, ...)
1580 {
1581 va_list args;
1582 int i;
1583
1584 va_start(args, fmt);
1585 i = vsnprintf(buf, size, fmt, args);
1586 va_end(args);
1587
1588 return i;
1589 }
1590 EXPORT_SYMBOL(snprintf);
1591
1592 /**
1593 * scnprintf - Format a string and place it in a buffer
1594 * @buf: The buffer to place the result into
1595 * @size: The size of the buffer, including the trailing null space
1596 * @fmt: The format string to use
1597 * @...: Arguments for the format string
1598 *
1599 * The return value is the number of characters written into @buf not including
1600 * the trailing '\0'. If @size is == 0 the function returns 0.
1601 */
1602
1603 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1604 {
1605 va_list args;
1606 int i;
1607
1608 va_start(args, fmt);
1609 i = vscnprintf(buf, size, fmt, args);
1610 va_end(args);
1611
1612 return i;
1613 }
1614 EXPORT_SYMBOL(scnprintf);
1615
1616 /**
1617 * vsprintf - Format a string and place it in a buffer
1618 * @buf: The buffer to place the result into
1619 * @fmt: The format string to use
1620 * @args: Arguments for the format string
1621 *
1622 * The function returns the number of characters written
1623 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1624 * buffer overflows.
1625 *
1626 * If you're not already dealing with a va_list consider using sprintf().
1627 *
1628 * See the vsnprintf() documentation for format string extensions over C99.
1629 */
1630 int vsprintf(char *buf, const char *fmt, va_list args)
1631 {
1632 return vsnprintf(buf, INT_MAX, fmt, args);
1633 }
1634 EXPORT_SYMBOL(vsprintf);
1635
1636 /**
1637 * sprintf - Format a string and place it in a buffer
1638 * @buf: The buffer to place the result into
1639 * @fmt: The format string to use
1640 * @...: Arguments for the format string
1641 *
1642 * The function returns the number of characters written
1643 * into @buf. Use snprintf() or scnprintf() in order to avoid
1644 * buffer overflows.
1645 *
1646 * See the vsnprintf() documentation for format string extensions over C99.
1647 */
1648 int sprintf(char *buf, const char *fmt, ...)
1649 {
1650 va_list args;
1651 int i;
1652
1653 va_start(args, fmt);
1654 i = vsnprintf(buf, INT_MAX, fmt, args);
1655 va_end(args);
1656
1657 return i;
1658 }
1659 EXPORT_SYMBOL(sprintf);
1660
1661 #ifdef CONFIG_BINARY_PRINTF
1662 /*
1663 * bprintf service:
1664 * vbin_printf() - VA arguments to binary data
1665 * bstr_printf() - Binary data to text string
1666 */
1667
1668 /**
1669 * vbin_printf - Parse a format string and place args' binary value in a buffer
1670 * @bin_buf: The buffer to place args' binary value
1671 * @size: The size of the buffer(by words(32bits), not characters)
1672 * @fmt: The format string to use
1673 * @args: Arguments for the format string
1674 *
1675 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1676 * is skiped.
1677 *
1678 * The return value is the number of words(32bits) which would be generated for
1679 * the given input.
1680 *
1681 * NOTE:
1682 * If the return value is greater than @size, the resulting bin_buf is NOT
1683 * valid for bstr_printf().
1684 */
1685 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1686 {
1687 struct printf_spec spec = {0};
1688 char *str, *end;
1689
1690 str = (char *)bin_buf;
1691 end = (char *)(bin_buf + size);
1692
1693 #define save_arg(type) \
1694 do { \
1695 if (sizeof(type) == 8) { \
1696 unsigned long long value; \
1697 str = PTR_ALIGN(str, sizeof(u32)); \
1698 value = va_arg(args, unsigned long long); \
1699 if (str + sizeof(type) <= end) { \
1700 *(u32 *)str = *(u32 *)&value; \
1701 *(u32 *)(str + 4) = *((u32 *)&value + 1); \
1702 } \
1703 } else { \
1704 unsigned long value; \
1705 str = PTR_ALIGN(str, sizeof(type)); \
1706 value = va_arg(args, int); \
1707 if (str + sizeof(type) <= end) \
1708 *(typeof(type) *)str = (type)value; \
1709 } \
1710 str += sizeof(type); \
1711 } while (0)
1712
1713 while (*fmt) {
1714 int read = format_decode(fmt, &spec);
1715
1716 fmt += read;
1717
1718 switch (spec.type) {
1719 case FORMAT_TYPE_NONE:
1720 case FORMAT_TYPE_INVALID:
1721 case FORMAT_TYPE_PERCENT_CHAR:
1722 break;
1723
1724 case FORMAT_TYPE_WIDTH:
1725 case FORMAT_TYPE_PRECISION:
1726 save_arg(int);
1727 break;
1728
1729 case FORMAT_TYPE_CHAR:
1730 save_arg(char);
1731 break;
1732
1733 case FORMAT_TYPE_STR: {
1734 const char *save_str = va_arg(args, char *);
1735 size_t len;
1736
1737 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1738 || (unsigned long)save_str < PAGE_SIZE)
1739 save_str = "(null)";
1740 len = strlen(save_str) + 1;
1741 if (str + len < end)
1742 memcpy(str, save_str, len);
1743 str += len;
1744 break;
1745 }
1746
1747 case FORMAT_TYPE_PTR:
1748 save_arg(void *);
1749 /* skip all alphanumeric pointer suffixes */
1750 while (isalnum(*fmt))
1751 fmt++;
1752 break;
1753
1754 case FORMAT_TYPE_NRCHARS: {
1755 /* skip %n 's argument */
1756 u8 qualifier = spec.qualifier;
1757 void *skip_arg;
1758 if (qualifier == 'l')
1759 skip_arg = va_arg(args, long *);
1760 else if (_tolower(qualifier) == 'z')
1761 skip_arg = va_arg(args, size_t *);
1762 else
1763 skip_arg = va_arg(args, int *);
1764 break;
1765 }
1766
1767 default:
1768 switch (spec.type) {
1769
1770 case FORMAT_TYPE_LONG_LONG:
1771 save_arg(long long);
1772 break;
1773 case FORMAT_TYPE_ULONG:
1774 case FORMAT_TYPE_LONG:
1775 save_arg(unsigned long);
1776 break;
1777 case FORMAT_TYPE_SIZE_T:
1778 save_arg(size_t);
1779 break;
1780 case FORMAT_TYPE_PTRDIFF:
1781 save_arg(ptrdiff_t);
1782 break;
1783 case FORMAT_TYPE_UBYTE:
1784 case FORMAT_TYPE_BYTE:
1785 save_arg(char);
1786 break;
1787 case FORMAT_TYPE_USHORT:
1788 case FORMAT_TYPE_SHORT:
1789 save_arg(short);
1790 break;
1791 default:
1792 save_arg(int);
1793 }
1794 }
1795 }
1796
1797 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1798 #undef save_arg
1799 }
1800 EXPORT_SYMBOL_GPL(vbin_printf);
1801
1802 /**
1803 * bstr_printf - Format a string from binary arguments and place it in a buffer
1804 * @buf: The buffer to place the result into
1805 * @size: The size of the buffer, including the trailing null space
1806 * @fmt: The format string to use
1807 * @bin_buf: Binary arguments for the format string
1808 *
1809 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1810 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1811 * a binary buffer that generated by vbin_printf.
1812 *
1813 * The format follows C99 vsnprintf, but has some extensions:
1814 * see vsnprintf comment for details.
1815 *
1816 * The return value is the number of characters which would
1817 * be generated for the given input, excluding the trailing
1818 * '\0', as per ISO C99. If you want to have the exact
1819 * number of characters written into @buf as return value
1820 * (not including the trailing '\0'), use vscnprintf(). If the
1821 * return is greater than or equal to @size, the resulting
1822 * string is truncated.
1823 */
1824 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1825 {
1826 struct printf_spec spec = {0};
1827 char *str, *end;
1828 const char *args = (const char *)bin_buf;
1829
1830 if (WARN_ON_ONCE((int) size < 0))
1831 return 0;
1832
1833 str = buf;
1834 end = buf + size;
1835
1836 #define get_arg(type) \
1837 ({ \
1838 typeof(type) value; \
1839 if (sizeof(type) == 8) { \
1840 args = PTR_ALIGN(args, sizeof(u32)); \
1841 *(u32 *)&value = *(u32 *)args; \
1842 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
1843 } else { \
1844 args = PTR_ALIGN(args, sizeof(type)); \
1845 value = *(typeof(type) *)args; \
1846 } \
1847 args += sizeof(type); \
1848 value; \
1849 })
1850
1851 /* Make sure end is always >= buf */
1852 if (end < buf) {
1853 end = ((void *)-1);
1854 size = end - buf;
1855 }
1856
1857 while (*fmt) {
1858 const char *old_fmt = fmt;
1859 int read = format_decode(fmt, &spec);
1860
1861 fmt += read;
1862
1863 switch (spec.type) {
1864 case FORMAT_TYPE_NONE: {
1865 int copy = read;
1866 if (str < end) {
1867 if (copy > end - str)
1868 copy = end - str;
1869 memcpy(str, old_fmt, copy);
1870 }
1871 str += read;
1872 break;
1873 }
1874
1875 case FORMAT_TYPE_WIDTH:
1876 spec.field_width = get_arg(int);
1877 break;
1878
1879 case FORMAT_TYPE_PRECISION:
1880 spec.precision = get_arg(int);
1881 break;
1882
1883 case FORMAT_TYPE_CHAR: {
1884 char c;
1885
1886 if (!(spec.flags & LEFT)) {
1887 while (--spec.field_width > 0) {
1888 if (str < end)
1889 *str = ' ';
1890 ++str;
1891 }
1892 }
1893 c = (unsigned char) get_arg(char);
1894 if (str < end)
1895 *str = c;
1896 ++str;
1897 while (--spec.field_width > 0) {
1898 if (str < end)
1899 *str = ' ';
1900 ++str;
1901 }
1902 break;
1903 }
1904
1905 case FORMAT_TYPE_STR: {
1906 const char *str_arg = args;
1907 args += strlen(str_arg) + 1;
1908 str = string(str, end, (char *)str_arg, spec);
1909 break;
1910 }
1911
1912 case FORMAT_TYPE_PTR:
1913 str = pointer(fmt+1, str, end, get_arg(void *), spec);
1914 while (isalnum(*fmt))
1915 fmt++;
1916 break;
1917
1918 case FORMAT_TYPE_PERCENT_CHAR:
1919 case FORMAT_TYPE_INVALID:
1920 if (str < end)
1921 *str = '%';
1922 ++str;
1923 break;
1924
1925 case FORMAT_TYPE_NRCHARS:
1926 /* skip */
1927 break;
1928
1929 default: {
1930 unsigned long long num;
1931
1932 switch (spec.type) {
1933
1934 case FORMAT_TYPE_LONG_LONG:
1935 num = get_arg(long long);
1936 break;
1937 case FORMAT_TYPE_ULONG:
1938 case FORMAT_TYPE_LONG:
1939 num = get_arg(unsigned long);
1940 break;
1941 case FORMAT_TYPE_SIZE_T:
1942 num = get_arg(size_t);
1943 break;
1944 case FORMAT_TYPE_PTRDIFF:
1945 num = get_arg(ptrdiff_t);
1946 break;
1947 case FORMAT_TYPE_UBYTE:
1948 num = get_arg(unsigned char);
1949 break;
1950 case FORMAT_TYPE_BYTE:
1951 num = get_arg(signed char);
1952 break;
1953 case FORMAT_TYPE_USHORT:
1954 num = get_arg(unsigned short);
1955 break;
1956 case FORMAT_TYPE_SHORT:
1957 num = get_arg(short);
1958 break;
1959 case FORMAT_TYPE_UINT:
1960 num = get_arg(unsigned int);
1961 break;
1962 default:
1963 num = get_arg(int);
1964 }
1965
1966 str = number(str, end, num, spec);
1967 } /* default: */
1968 } /* switch(spec.type) */
1969 } /* while(*fmt) */
1970
1971 if (size > 0) {
1972 if (str < end)
1973 *str = '\0';
1974 else
1975 end[-1] = '\0';
1976 }
1977
1978 #undef get_arg
1979
1980 /* the trailing null byte doesn't count towards the total */
1981 return str - buf;
1982 }
1983 EXPORT_SYMBOL_GPL(bstr_printf);
1984
1985 /**
1986 * bprintf - Parse a format string and place args' binary value in a buffer
1987 * @bin_buf: The buffer to place args' binary value
1988 * @size: The size of the buffer(by words(32bits), not characters)
1989 * @fmt: The format string to use
1990 * @...: Arguments for the format string
1991 *
1992 * The function returns the number of words(u32) written
1993 * into @bin_buf.
1994 */
1995 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1996 {
1997 va_list args;
1998 int ret;
1999
2000 va_start(args, fmt);
2001 ret = vbin_printf(bin_buf, size, fmt, args);
2002 va_end(args);
2003
2004 return ret;
2005 }
2006 EXPORT_SYMBOL_GPL(bprintf);
2007
2008 #endif /* CONFIG_BINARY_PRINTF */
2009
2010 /**
2011 * vsscanf - Unformat a buffer into a list of arguments
2012 * @buf: input buffer
2013 * @fmt: format of buffer
2014 * @args: arguments
2015 */
2016 int vsscanf(const char *buf, const char *fmt, va_list args)
2017 {
2018 const char *str = buf;
2019 char *next;
2020 char digit;
2021 int num = 0;
2022 u8 qualifier;
2023 u8 base;
2024 s16 field_width;
2025 bool is_sign;
2026
2027 while (*fmt && *str) {
2028 /* skip any white space in format */
2029 /* white space in format matchs any amount of
2030 * white space, including none, in the input.
2031 */
2032 if (isspace(*fmt)) {
2033 fmt = skip_spaces(++fmt);
2034 str = skip_spaces(str);
2035 }
2036
2037 /* anything that is not a conversion must match exactly */
2038 if (*fmt != '%' && *fmt) {
2039 if (*fmt++ != *str++)
2040 break;
2041 continue;
2042 }
2043
2044 if (!*fmt)
2045 break;
2046 ++fmt;
2047
2048 /* skip this conversion.
2049 * advance both strings to next white space
2050 */
2051 if (*fmt == '*') {
2052 while (!isspace(*fmt) && *fmt != '%' && *fmt)
2053 fmt++;
2054 while (!isspace(*str) && *str)
2055 str++;
2056 continue;
2057 }
2058
2059 /* get field width */
2060 field_width = -1;
2061 if (isdigit(*fmt))
2062 field_width = skip_atoi(&fmt);
2063
2064 /* get conversion qualifier */
2065 qualifier = -1;
2066 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2067 _tolower(*fmt) == 'z') {
2068 qualifier = *fmt++;
2069 if (unlikely(qualifier == *fmt)) {
2070 if (qualifier == 'h') {
2071 qualifier = 'H';
2072 fmt++;
2073 } else if (qualifier == 'l') {
2074 qualifier = 'L';
2075 fmt++;
2076 }
2077 }
2078 }
2079
2080 if (!*fmt || !*str)
2081 break;
2082
2083 base = 10;
2084 is_sign = 0;
2085
2086 switch (*fmt++) {
2087 case 'c':
2088 {
2089 char *s = (char *)va_arg(args, char*);
2090 if (field_width == -1)
2091 field_width = 1;
2092 do {
2093 *s++ = *str++;
2094 } while (--field_width > 0 && *str);
2095 num++;
2096 }
2097 continue;
2098 case 's':
2099 {
2100 char *s = (char *)va_arg(args, char *);
2101 if (field_width == -1)
2102 field_width = SHRT_MAX;
2103 /* first, skip leading white space in buffer */
2104 str = skip_spaces(str);
2105
2106 /* now copy until next white space */
2107 while (*str && !isspace(*str) && field_width--)
2108 *s++ = *str++;
2109 *s = '\0';
2110 num++;
2111 }
2112 continue;
2113 case 'n':
2114 /* return number of characters read so far */
2115 {
2116 int *i = (int *)va_arg(args, int*);
2117 *i = str - buf;
2118 }
2119 continue;
2120 case 'o':
2121 base = 8;
2122 break;
2123 case 'x':
2124 case 'X':
2125 base = 16;
2126 break;
2127 case 'i':
2128 base = 0;
2129 case 'd':
2130 is_sign = 1;
2131 case 'u':
2132 break;
2133 case '%':
2134 /* looking for '%' in str */
2135 if (*str++ != '%')
2136 return num;
2137 continue;
2138 default:
2139 /* invalid format; stop here */
2140 return num;
2141 }
2142
2143 /* have some sort of integer conversion.
2144 * first, skip white space in buffer.
2145 */
2146 str = skip_spaces(str);
2147
2148 digit = *str;
2149 if (is_sign && digit == '-')
2150 digit = *(str + 1);
2151
2152 if (!digit
2153 || (base == 16 && !isxdigit(digit))
2154 || (base == 10 && !isdigit(digit))
2155 || (base == 8 && (!isdigit(digit) || digit > '7'))
2156 || (base == 0 && !isdigit(digit)))
2157 break;
2158
2159 switch (qualifier) {
2160 case 'H': /* that's 'hh' in format */
2161 if (is_sign) {
2162 signed char *s = (signed char *)va_arg(args, signed char *);
2163 *s = (signed char)simple_strtol(str, &next, base);
2164 } else {
2165 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2166 *s = (unsigned char)simple_strtoul(str, &next, base);
2167 }
2168 break;
2169 case 'h':
2170 if (is_sign) {
2171 short *s = (short *)va_arg(args, short *);
2172 *s = (short)simple_strtol(str, &next, base);
2173 } else {
2174 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2175 *s = (unsigned short)simple_strtoul(str, &next, base);
2176 }
2177 break;
2178 case 'l':
2179 if (is_sign) {
2180 long *l = (long *)va_arg(args, long *);
2181 *l = simple_strtol(str, &next, base);
2182 } else {
2183 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2184 *l = simple_strtoul(str, &next, base);
2185 }
2186 break;
2187 case 'L':
2188 if (is_sign) {
2189 long long *l = (long long *)va_arg(args, long long *);
2190 *l = simple_strtoll(str, &next, base);
2191 } else {
2192 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2193 *l = simple_strtoull(str, &next, base);
2194 }
2195 break;
2196 case 'Z':
2197 case 'z':
2198 {
2199 size_t *s = (size_t *)va_arg(args, size_t *);
2200 *s = (size_t)simple_strtoul(str, &next, base);
2201 }
2202 break;
2203 default:
2204 if (is_sign) {
2205 int *i = (int *)va_arg(args, int *);
2206 *i = (int)simple_strtol(str, &next, base);
2207 } else {
2208 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2209 *i = (unsigned int)simple_strtoul(str, &next, base);
2210 }
2211 break;
2212 }
2213 num++;
2214
2215 if (!next)
2216 break;
2217 str = next;
2218 }
2219
2220 /*
2221 * Now we've come all the way through so either the input string or the
2222 * format ended. In the former case, there can be a %n at the current
2223 * position in the format that needs to be filled.
2224 */
2225 if (*fmt == '%' && *(fmt + 1) == 'n') {
2226 int *p = (int *)va_arg(args, int *);
2227 *p = str - buf;
2228 }
2229
2230 return num;
2231 }
2232 EXPORT_SYMBOL(vsscanf);
2233
2234 /**
2235 * sscanf - Unformat a buffer into a list of arguments
2236 * @buf: input buffer
2237 * @fmt: formatting of buffer
2238 * @...: resulting arguments
2239 */
2240 int sscanf(const char *buf, const char *fmt, ...)
2241 {
2242 va_list args;
2243 int i;
2244
2245 va_start(args, fmt);
2246 i = vsscanf(buf, fmt, args);
2247 va_end(args);
2248
2249 return i;
2250 }
2251 EXPORT_SYMBOL(sscanf);
Linux kernel - Deliverables
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