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/math64.h>
27 #include <linux/uaccess.h>
28 #include <linux/ioport.h>
29 #include <net/addrconf.h>
30
31 #include <asm/page.h> /* for PAGE_SIZE */
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42 * This function is obsolete. Please use kstrtoull instead.
43 */
simple_strtoull(const char * cp,char ** endp,unsigned int base)44 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
45 {
46 unsigned long long result;
47 unsigned int rv;
48
49 cp = _parse_integer_fixup_radix(cp, &base);
50 rv = _parse_integer(cp, base, &result);
51 /* FIXME */
52 cp += (rv & ~KSTRTOX_OVERFLOW);
53
54 if (endp)
55 *endp = (char *)cp;
56
57 return result;
58 }
59 EXPORT_SYMBOL(simple_strtoull);
60
61 /**
62 * simple_strtoul - convert a string to an unsigned long
63 * @cp: The start of the string
64 * @endp: A pointer to the end of the parsed string will be placed here
65 * @base: The number base to use
66 *
67 * This function is obsolete. Please use kstrtoul instead.
68 */
simple_strtoul(const char * cp,char ** endp,unsigned int base)69 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
70 {
71 return simple_strtoull(cp, endp, base);
72 }
73 EXPORT_SYMBOL(simple_strtoul);
74
75 /**
76 * simple_strtol - convert a string to a signed long
77 * @cp: The start of the string
78 * @endp: A pointer to the end of the parsed string will be placed here
79 * @base: The number base to use
80 *
81 * This function is obsolete. Please use kstrtol instead.
82 */
simple_strtol(const char * cp,char ** endp,unsigned int base)83 long simple_strtol(const char *cp, char **endp, unsigned int base)
84 {
85 if (*cp == '-')
86 return -simple_strtoul(cp + 1, endp, base);
87
88 return simple_strtoul(cp, endp, base);
89 }
90 EXPORT_SYMBOL(simple_strtol);
91
92 /**
93 * simple_strtoll - convert a string to a signed long long
94 * @cp: The start of the string
95 * @endp: A pointer to the end of the parsed string will be placed here
96 * @base: The number base to use
97 *
98 * This function is obsolete. Please use kstrtoll instead.
99 */
simple_strtoll(const char * cp,char ** endp,unsigned int base)100 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
101 {
102 if (*cp == '-')
103 return -simple_strtoull(cp + 1, endp, base);
104
105 return simple_strtoull(cp, endp, base);
106 }
107 EXPORT_SYMBOL(simple_strtoll);
108
109 static noinline_for_stack
skip_atoi(const char ** s)110 int skip_atoi(const char **s)
111 {
112 int i = 0;
113
114 while (isdigit(**s))
115 i = i*10 + *((*s)++) - '0';
116
117 return i;
118 }
119
120 /* Decimal conversion is by far the most typical, and is used
121 * for /proc and /sys data. This directly impacts e.g. top performance
122 * with many processes running. We optimize it for speed
123 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
124 * (with permission from the author, Douglas W. Jones).
125 */
126
127 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
128 /* Formats correctly any integer in [0, 999999999] */
129 static noinline_for_stack
put_dec_full9(char * buf,unsigned q)130 char *put_dec_full9(char *buf, unsigned q)
131 {
132 unsigned r;
133
134 /*
135 * Possible ways to approx. divide by 10
136 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
137 * (x * 0xcccd) >> 19 x < 81920 (x < 262149 when 64-bit mul)
138 * (x * 0x6667) >> 18 x < 43699
139 * (x * 0x3334) >> 17 x < 16389
140 * (x * 0x199a) >> 16 x < 16389
141 * (x * 0x0ccd) >> 15 x < 16389
142 * (x * 0x0667) >> 14 x < 2739
143 * (x * 0x0334) >> 13 x < 1029
144 * (x * 0x019a) >> 12 x < 1029
145 * (x * 0x00cd) >> 11 x < 1029 shorter code than * 0x67 (on i386)
146 * (x * 0x0067) >> 10 x < 179
147 * (x * 0x0034) >> 9 x < 69 same
148 * (x * 0x001a) >> 8 x < 69 same
149 * (x * 0x000d) >> 7 x < 69 same, shortest code (on i386)
150 * (x * 0x0007) >> 6 x < 19
151 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
152 */
153 r = (q * (uint64_t)0x1999999a) >> 32;
154 *buf++ = (q - 10 * r) + '0'; /* 1 */
155 q = (r * (uint64_t)0x1999999a) >> 32;
156 *buf++ = (r - 10 * q) + '0'; /* 2 */
157 r = (q * (uint64_t)0x1999999a) >> 32;
158 *buf++ = (q - 10 * r) + '0'; /* 3 */
159 q = (r * (uint64_t)0x1999999a) >> 32;
160 *buf++ = (r - 10 * q) + '0'; /* 4 */
161 r = (q * (uint64_t)0x1999999a) >> 32;
162 *buf++ = (q - 10 * r) + '0'; /* 5 */
163 /* Now value is under 10000, can avoid 64-bit multiply */
164 q = (r * 0x199a) >> 16;
165 *buf++ = (r - 10 * q) + '0'; /* 6 */
166 r = (q * 0xcd) >> 11;
167 *buf++ = (q - 10 * r) + '0'; /* 7 */
168 q = (r * 0xcd) >> 11;
169 *buf++ = (r - 10 * q) + '0'; /* 8 */
170 *buf++ = q + '0'; /* 9 */
171 return buf;
172 }
173 #endif
174
175 /* Similar to above but do not pad with zeros.
176 * Code can be easily arranged to print 9 digits too, but our callers
177 * always call put_dec_full9() instead when the number has 9 decimal digits.
178 */
179 static noinline_for_stack
put_dec_trunc8(char * buf,unsigned r)180 char *put_dec_trunc8(char *buf, unsigned r)
181 {
182 unsigned q;
183
184 /* Copy of previous function's body with added early returns */
185 while (r >= 10000) {
186 q = r + '0';
187 r = (r * (uint64_t)0x1999999a) >> 32;
188 *buf++ = q - 10*r;
189 }
190
191 q = (r * 0x199a) >> 16; /* r <= 9999 */
192 *buf++ = (r - 10 * q) + '0';
193 if (q == 0)
194 return buf;
195 r = (q * 0xcd) >> 11; /* q <= 999 */
196 *buf++ = (q - 10 * r) + '0';
197 if (r == 0)
198 return buf;
199 q = (r * 0xcd) >> 11; /* r <= 99 */
200 *buf++ = (r - 10 * q) + '0';
201 if (q == 0)
202 return buf;
203 *buf++ = q + '0'; /* q <= 9 */
204 return buf;
205 }
206
207 /* There are two algorithms to print larger numbers.
208 * One is generic: divide by 1000000000 and repeatedly print
209 * groups of (up to) 9 digits. It's conceptually simple,
210 * but requires a (unsigned long long) / 1000000000 division.
211 *
212 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
213 * manipulates them cleverly and generates groups of 4 decimal digits.
214 * It so happens that it does NOT require long long division.
215 *
216 * If long is > 32 bits, division of 64-bit values is relatively easy,
217 * and we will use the first algorithm.
218 * If long long is > 64 bits (strange architecture with VERY large long long),
219 * second algorithm can't be used, and we again use the first one.
220 *
221 * Else (if long is 32 bits and long long is 64 bits) we use second one.
222 */
223
224 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
225
226 /* First algorithm: generic */
227
228 static
put_dec(char * buf,unsigned long long n)229 char *put_dec(char *buf, unsigned long long n)
230 {
231 if (n >= 100*1000*1000) {
232 while (n >= 1000*1000*1000)
233 buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
234 if (n >= 100*1000*1000)
235 return put_dec_full9(buf, n);
236 }
237 return put_dec_trunc8(buf, n);
238 }
239
240 #else
241
242 /* Second algorithm: valid only for 64-bit long longs */
243
244 /* See comment in put_dec_full9 for choice of constants */
245 static noinline_for_stack
put_dec_full4(char * buf,unsigned q)246 void put_dec_full4(char *buf, unsigned q)
247 {
248 unsigned r;
249 r = (q * 0xccd) >> 15;
250 buf[0] = (q - 10 * r) + '0';
251 q = (r * 0xcd) >> 11;
252 buf[1] = (r - 10 * q) + '0';
253 r = (q * 0xcd) >> 11;
254 buf[2] = (q - 10 * r) + '0';
255 buf[3] = r + '0';
256 }
257
258 /*
259 * Call put_dec_full4 on x % 10000, return x / 10000.
260 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
261 * holds for all x < 1,128,869,999. The largest value this
262 * helper will ever be asked to convert is 1,125,520,955.
263 * (d1 in the put_dec code, assuming n is all-ones).
264 */
265 static
put_dec_helper4(char * buf,unsigned x)266 unsigned put_dec_helper4(char *buf, unsigned x)
267 {
268 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
269
270 put_dec_full4(buf, x - q * 10000);
271 return q;
272 }
273
274 /* Based on code by Douglas W. Jones found at
275 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
276 * (with permission from the author).
277 * Performs no 64-bit division and hence should be fast on 32-bit machines.
278 */
279 static
put_dec(char * buf,unsigned long long n)280 char *put_dec(char *buf, unsigned long long n)
281 {
282 uint32_t d3, d2, d1, q, h;
283
284 if (n < 100*1000*1000)
285 return put_dec_trunc8(buf, n);
286
287 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
288 h = (n >> 32);
289 d2 = (h ) & 0xffff;
290 d3 = (h >> 16); /* implicit "& 0xffff" */
291
292 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
293 q = put_dec_helper4(buf, q);
294
295 q += 7671 * d3 + 9496 * d2 + 6 * d1;
296 q = put_dec_helper4(buf+4, q);
297
298 q += 4749 * d3 + 42 * d2;
299 q = put_dec_helper4(buf+8, q);
300
301 q += 281 * d3;
302 buf += 12;
303 if (q)
304 buf = put_dec_trunc8(buf, q);
305 else while (buf[-1] == '0')
306 --buf;
307
308 return buf;
309 }
310
311 #endif
312
313 /*
314 * Convert passed number to decimal string.
315 * Returns the length of string. On buffer overflow, returns 0.
316 *
317 * If speed is not important, use snprintf(). It's easy to read the code.
318 */
num_to_str(char * buf,int size,unsigned long long num)319 int num_to_str(char *buf, int size, unsigned long long num)
320 {
321 char tmp[sizeof(num) * 3];
322 int idx, len;
323
324 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
325 if (num <= 9) {
326 tmp[0] = '0' + num;
327 len = 1;
328 } else {
329 len = put_dec(tmp, num) - tmp;
330 }
331
332 if (len > size)
333 return 0;
334 for (idx = 0; idx < len; ++idx)
335 buf[idx] = tmp[len - idx - 1];
336 return len;
337 }
338
339 #define ZEROPAD 1 /* pad with zero */
340 #define SIGN 2 /* unsigned/signed long */
341 #define PLUS 4 /* show plus */
342 #define SPACE 8 /* space if plus */
343 #define LEFT 16 /* left justified */
344 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
345 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
346
347 enum format_type {
348 FORMAT_TYPE_NONE, /* Just a string part */
349 FORMAT_TYPE_WIDTH,
350 FORMAT_TYPE_PRECISION,
351 FORMAT_TYPE_CHAR,
352 FORMAT_TYPE_STR,
353 FORMAT_TYPE_PTR,
354 FORMAT_TYPE_PERCENT_CHAR,
355 FORMAT_TYPE_INVALID,
356 FORMAT_TYPE_LONG_LONG,
357 FORMAT_TYPE_ULONG,
358 FORMAT_TYPE_LONG,
359 FORMAT_TYPE_UBYTE,
360 FORMAT_TYPE_BYTE,
361 FORMAT_TYPE_USHORT,
362 FORMAT_TYPE_SHORT,
363 FORMAT_TYPE_UINT,
364 FORMAT_TYPE_INT,
365 FORMAT_TYPE_NRCHARS,
366 FORMAT_TYPE_SIZE_T,
367 FORMAT_TYPE_PTRDIFF
368 };
369
370 struct printf_spec {
371 u8 type; /* format_type enum */
372 u8 flags; /* flags to number() */
373 u8 base; /* number base, 8, 10 or 16 only */
374 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */
375 s16 field_width; /* width of output field */
376 s16 precision; /* # of digits/chars */
377 };
378
379 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)380 char *number(char *buf, char *end, unsigned long long num,
381 struct printf_spec spec)
382 {
383 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
384 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
385
386 char tmp[66];
387 char sign;
388 char locase;
389 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
390 int i;
391 bool is_zero = num == 0LL;
392
393 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
394 * produces same digits or (maybe lowercased) letters */
395 locase = (spec.flags & SMALL);
396 if (spec.flags & LEFT)
397 spec.flags &= ~ZEROPAD;
398 sign = 0;
399 if (spec.flags & SIGN) {
400 if ((signed long long)num < 0) {
401 sign = '-';
402 num = -(signed long long)num;
403 spec.field_width--;
404 } else if (spec.flags & PLUS) {
405 sign = '+';
406 spec.field_width--;
407 } else if (spec.flags & SPACE) {
408 sign = ' ';
409 spec.field_width--;
410 }
411 }
412 if (need_pfx) {
413 if (spec.base == 16)
414 spec.field_width -= 2;
415 else if (!is_zero)
416 spec.field_width--;
417 }
418
419 /* generate full string in tmp[], in reverse order */
420 i = 0;
421 if (num < spec.base)
422 tmp[i++] = digits[num] | locase;
423 /* Generic code, for any base:
424 else do {
425 tmp[i++] = (digits[do_div(num,base)] | locase);
426 } while (num != 0);
427 */
428 else if (spec.base != 10) { /* 8 or 16 */
429 int mask = spec.base - 1;
430 int shift = 3;
431
432 if (spec.base == 16)
433 shift = 4;
434 do {
435 tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
436 num >>= shift;
437 } while (num);
438 } else { /* base 10 */
439 i = put_dec(tmp, num) - tmp;
440 }
441
442 /* printing 100 using %2d gives "100", not "00" */
443 if (i > spec.precision)
444 spec.precision = i;
445 /* leading space padding */
446 spec.field_width -= spec.precision;
447 if (!(spec.flags & (ZEROPAD+LEFT))) {
448 while (--spec.field_width >= 0) {
449 if (buf < end)
450 *buf = ' ';
451 ++buf;
452 }
453 }
454 /* sign */
455 if (sign) {
456 if (buf < end)
457 *buf = sign;
458 ++buf;
459 }
460 /* "0x" / "0" prefix */
461 if (need_pfx) {
462 if (spec.base == 16 || !is_zero) {
463 if (buf < end)
464 *buf = '0';
465 ++buf;
466 }
467 if (spec.base == 16) {
468 if (buf < end)
469 *buf = ('X' | locase);
470 ++buf;
471 }
472 }
473 /* zero or space padding */
474 if (!(spec.flags & LEFT)) {
475 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
476 while (--spec.field_width >= 0) {
477 if (buf < end)
478 *buf = c;
479 ++buf;
480 }
481 }
482 /* hmm even more zero padding? */
483 while (i <= --spec.precision) {
484 if (buf < end)
485 *buf = '0';
486 ++buf;
487 }
488 /* actual digits of result */
489 while (--i >= 0) {
490 if (buf < end)
491 *buf = tmp[i];
492 ++buf;
493 }
494 /* trailing space padding */
495 while (--spec.field_width >= 0) {
496 if (buf < end)
497 *buf = ' ';
498 ++buf;
499 }
500
501 return buf;
502 }
503
504 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)505 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
506 {
507 int len, i;
508
509 if ((unsigned long)s < PAGE_SIZE)
510 s = "(null)";
511
512 len = strnlen(s, spec.precision);
513
514 if (!(spec.flags & LEFT)) {
515 while (len < spec.field_width--) {
516 if (buf < end)
517 *buf = ' ';
518 ++buf;
519 }
520 }
521 for (i = 0; i < len; ++i) {
522 if (buf < end)
523 *buf = *s;
524 ++buf; ++s;
525 }
526 while (len < spec.field_width--) {
527 if (buf < end)
528 *buf = ' ';
529 ++buf;
530 }
531
532 return buf;
533 }
534
535 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)536 char *symbol_string(char *buf, char *end, void *ptr,
537 struct printf_spec spec, const char *fmt)
538 {
539 unsigned long value;
540 #ifdef CONFIG_KALLSYMS
541 char sym[KSYM_SYMBOL_LEN];
542 #endif
543
544 if (fmt[1] == 'R')
545 ptr = __builtin_extract_return_addr(ptr);
546 value = (unsigned long)ptr;
547
548 #ifdef CONFIG_KALLSYMS
549 if (*fmt == 'B')
550 sprint_backtrace(sym, value);
551 else if (*fmt != 'f' && *fmt != 's')
552 sprint_symbol(sym, value);
553 else
554 sprint_symbol_no_offset(sym, value);
555
556 return string(buf, end, sym, spec);
557 #else
558 spec.field_width = 2 * sizeof(void *);
559 spec.flags |= SPECIAL | SMALL | ZEROPAD;
560 spec.base = 16;
561
562 return number(buf, end, value, spec);
563 #endif
564 }
565
566 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)567 char *resource_string(char *buf, char *end, struct resource *res,
568 struct printf_spec spec, const char *fmt)
569 {
570 #ifndef IO_RSRC_PRINTK_SIZE
571 #define IO_RSRC_PRINTK_SIZE 6
572 #endif
573
574 #ifndef MEM_RSRC_PRINTK_SIZE
575 #define MEM_RSRC_PRINTK_SIZE 10
576 #endif
577 static const struct printf_spec io_spec = {
578 .base = 16,
579 .field_width = IO_RSRC_PRINTK_SIZE,
580 .precision = -1,
581 .flags = SPECIAL | SMALL | ZEROPAD,
582 };
583 static const struct printf_spec mem_spec = {
584 .base = 16,
585 .field_width = MEM_RSRC_PRINTK_SIZE,
586 .precision = -1,
587 .flags = SPECIAL | SMALL | ZEROPAD,
588 };
589 static const struct printf_spec bus_spec = {
590 .base = 16,
591 .field_width = 2,
592 .precision = -1,
593 .flags = SMALL | ZEROPAD,
594 };
595 static const struct printf_spec dec_spec = {
596 .base = 10,
597 .precision = -1,
598 .flags = 0,
599 };
600 static const struct printf_spec str_spec = {
601 .field_width = -1,
602 .precision = 10,
603 .flags = LEFT,
604 };
605 static const struct printf_spec flag_spec = {
606 .base = 16,
607 .precision = -1,
608 .flags = SPECIAL | SMALL,
609 };
610
611 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
612 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
613 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
614 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
615 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
616 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
617 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
618 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
619
620 char *p = sym, *pend = sym + sizeof(sym);
621 int decode = (fmt[0] == 'R') ? 1 : 0;
622 const struct printf_spec *specp;
623
624 *p++ = '[';
625 if (res->flags & IORESOURCE_IO) {
626 p = string(p, pend, "io ", str_spec);
627 specp = &io_spec;
628 } else if (res->flags & IORESOURCE_MEM) {
629 p = string(p, pend, "mem ", str_spec);
630 specp = &mem_spec;
631 } else if (res->flags & IORESOURCE_IRQ) {
632 p = string(p, pend, "irq ", str_spec);
633 specp = &dec_spec;
634 } else if (res->flags & IORESOURCE_DMA) {
635 p = string(p, pend, "dma ", str_spec);
636 specp = &dec_spec;
637 } else if (res->flags & IORESOURCE_BUS) {
638 p = string(p, pend, "bus ", str_spec);
639 specp = &bus_spec;
640 } else {
641 p = string(p, pend, "??? ", str_spec);
642 specp = &mem_spec;
643 decode = 0;
644 }
645 p = number(p, pend, res->start, *specp);
646 if (res->start != res->end) {
647 *p++ = '-';
648 p = number(p, pend, res->end, *specp);
649 }
650 if (decode) {
651 if (res->flags & IORESOURCE_MEM_64)
652 p = string(p, pend, " 64bit", str_spec);
653 if (res->flags & IORESOURCE_PREFETCH)
654 p = string(p, pend, " pref", str_spec);
655 if (res->flags & IORESOURCE_WINDOW)
656 p = string(p, pend, " window", str_spec);
657 if (res->flags & IORESOURCE_DISABLED)
658 p = string(p, pend, " disabled", str_spec);
659 } else {
660 p = string(p, pend, " flags ", str_spec);
661 p = number(p, pend, res->flags, flag_spec);
662 }
663 *p++ = ']';
664 *p = '\0';
665
666 return string(buf, end, sym, spec);
667 }
668
669 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)670 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
671 const char *fmt)
672 {
673 int i, len = 1; /* if we pass '%ph[CDN]', field witdh remains
674 negative value, fallback to the default */
675 char separator;
676
677 if (spec.field_width == 0)
678 /* nothing to print */
679 return buf;
680
681 if (ZERO_OR_NULL_PTR(addr))
682 /* NULL pointer */
683 return string(buf, end, NULL, spec);
684
685 switch (fmt[1]) {
686 case 'C':
687 separator = ':';
688 break;
689 case 'D':
690 separator = '-';
691 break;
692 case 'N':
693 separator = 0;
694 break;
695 default:
696 separator = ' ';
697 break;
698 }
699
700 if (spec.field_width > 0)
701 len = min_t(int, spec.field_width, 64);
702
703 for (i = 0; i < len && buf < end - 1; i++) {
704 buf = hex_byte_pack(buf, addr[i]);
705
706 if (buf < end && separator && i != len - 1)
707 *buf++ = separator;
708 }
709
710 return buf;
711 }
712
713 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)714 char *mac_address_string(char *buf, char *end, u8 *addr,
715 struct printf_spec spec, const char *fmt)
716 {
717 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
718 char *p = mac_addr;
719 int i;
720 char separator;
721 bool reversed = false;
722
723 switch (fmt[1]) {
724 case 'F':
725 separator = '-';
726 break;
727
728 case 'R':
729 reversed = true;
730 /* fall through */
731
732 default:
733 separator = ':';
734 break;
735 }
736
737 for (i = 0; i < 6; i++) {
738 if (reversed)
739 p = hex_byte_pack(p, addr[5 - i]);
740 else
741 p = hex_byte_pack(p, addr[i]);
742
743 if (fmt[0] == 'M' && i != 5)
744 *p++ = separator;
745 }
746 *p = '\0';
747
748 return string(buf, end, mac_addr, spec);
749 }
750
751 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)752 char *ip4_string(char *p, const u8 *addr, const char *fmt)
753 {
754 int i;
755 bool leading_zeros = (fmt[0] == 'i');
756 int index;
757 int step;
758
759 switch (fmt[2]) {
760 case 'h':
761 #ifdef __BIG_ENDIAN
762 index = 0;
763 step = 1;
764 #else
765 index = 3;
766 step = -1;
767 #endif
768 break;
769 case 'l':
770 index = 3;
771 step = -1;
772 break;
773 case 'n':
774 case 'b':
775 default:
776 index = 0;
777 step = 1;
778 break;
779 }
780 for (i = 0; i < 4; i++) {
781 char temp[3]; /* hold each IP quad in reverse order */
782 int digits = put_dec_trunc8(temp, addr[index]) - temp;
783 if (leading_zeros) {
784 if (digits < 3)
785 *p++ = '0';
786 if (digits < 2)
787 *p++ = '0';
788 }
789 /* reverse the digits in the quad */
790 while (digits--)
791 *p++ = temp[digits];
792 if (i < 3)
793 *p++ = '.';
794 index += step;
795 }
796 *p = '\0';
797
798 return p;
799 }
800
801 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)802 char *ip6_compressed_string(char *p, const char *addr)
803 {
804 int i, j, range;
805 unsigned char zerolength[8];
806 int longest = 1;
807 int colonpos = -1;
808 u16 word;
809 u8 hi, lo;
810 bool needcolon = false;
811 bool useIPv4;
812 struct in6_addr in6;
813
814 memcpy(&in6, addr, sizeof(struct in6_addr));
815
816 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
817
818 memset(zerolength, 0, sizeof(zerolength));
819
820 if (useIPv4)
821 range = 6;
822 else
823 range = 8;
824
825 /* find position of longest 0 run */
826 for (i = 0; i < range; i++) {
827 for (j = i; j < range; j++) {
828 if (in6.s6_addr16[j] != 0)
829 break;
830 zerolength[i]++;
831 }
832 }
833 for (i = 0; i < range; i++) {
834 if (zerolength[i] > longest) {
835 longest = zerolength[i];
836 colonpos = i;
837 }
838 }
839 if (longest == 1) /* don't compress a single 0 */
840 colonpos = -1;
841
842 /* emit address */
843 for (i = 0; i < range; i++) {
844 if (i == colonpos) {
845 if (needcolon || i == 0)
846 *p++ = ':';
847 *p++ = ':';
848 needcolon = false;
849 i += longest - 1;
850 continue;
851 }
852 if (needcolon) {
853 *p++ = ':';
854 needcolon = false;
855 }
856 /* hex u16 without leading 0s */
857 word = ntohs(in6.s6_addr16[i]);
858 hi = word >> 8;
859 lo = word & 0xff;
860 if (hi) {
861 if (hi > 0x0f)
862 p = hex_byte_pack(p, hi);
863 else
864 *p++ = hex_asc_lo(hi);
865 p = hex_byte_pack(p, lo);
866 }
867 else if (lo > 0x0f)
868 p = hex_byte_pack(p, lo);
869 else
870 *p++ = hex_asc_lo(lo);
871 needcolon = true;
872 }
873
874 if (useIPv4) {
875 if (needcolon)
876 *p++ = ':';
877 p = ip4_string(p, &in6.s6_addr[12], "I4");
878 }
879 *p = '\0';
880
881 return p;
882 }
883
884 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)885 char *ip6_string(char *p, const char *addr, const char *fmt)
886 {
887 int i;
888
889 for (i = 0; i < 8; i++) {
890 p = hex_byte_pack(p, *addr++);
891 p = hex_byte_pack(p, *addr++);
892 if (fmt[0] == 'I' && i != 7)
893 *p++ = ':';
894 }
895 *p = '\0';
896
897 return p;
898 }
899
900 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)901 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
902 struct printf_spec spec, const char *fmt)
903 {
904 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
905
906 if (fmt[0] == 'I' && fmt[2] == 'c')
907 ip6_compressed_string(ip6_addr, addr);
908 else
909 ip6_string(ip6_addr, addr, fmt);
910
911 return string(buf, end, ip6_addr, spec);
912 }
913
914 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)915 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
916 struct printf_spec spec, const char *fmt)
917 {
918 char ip4_addr[sizeof("255.255.255.255")];
919
920 ip4_string(ip4_addr, addr, fmt);
921
922 return string(buf, end, ip4_addr, spec);
923 }
924
925 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)926 char *uuid_string(char *buf, char *end, const u8 *addr,
927 struct printf_spec spec, const char *fmt)
928 {
929 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
930 char *p = uuid;
931 int i;
932 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
933 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
934 const u8 *index = be;
935 bool uc = false;
936
937 switch (*(++fmt)) {
938 case 'L':
939 uc = true; /* fall-through */
940 case 'l':
941 index = le;
942 break;
943 case 'B':
944 uc = true;
945 break;
946 }
947
948 for (i = 0; i < 16; i++) {
949 p = hex_byte_pack(p, addr[index[i]]);
950 switch (i) {
951 case 3:
952 case 5:
953 case 7:
954 case 9:
955 *p++ = '-';
956 break;
957 }
958 }
959
960 *p = 0;
961
962 if (uc) {
963 p = uuid;
964 do {
965 *p = toupper(*p);
966 } while (*(++p));
967 }
968
969 return string(buf, end, uuid, spec);
970 }
971
972 static
netdev_feature_string(char * buf,char * end,const u8 * addr,struct printf_spec spec)973 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
974 struct printf_spec spec)
975 {
976 spec.flags |= SPECIAL | SMALL | ZEROPAD;
977 if (spec.field_width == -1)
978 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
979 spec.base = 16;
980
981 return number(buf, end, *(const netdev_features_t *)addr, spec);
982 }
983
984 int kptr_restrict __read_mostly;
985
986 /*
987 * Show a '%p' thing. A kernel extension is that the '%p' is followed
988 * by an extra set of alphanumeric characters that are extended format
989 * specifiers.
990 *
991 * Right now we handle:
992 *
993 * - 'F' For symbolic function descriptor pointers with offset
994 * - 'f' For simple symbolic function names without offset
995 * - 'S' For symbolic direct pointers with offset
996 * - 's' For symbolic direct pointers without offset
997 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
998 * - 'B' For backtraced symbolic direct pointers with offset
999 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1000 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1001 * - 'M' For a 6-byte MAC address, it prints the address in the
1002 * usual colon-separated hex notation
1003 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1004 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1005 * with a dash-separated hex notation
1006 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1007 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1008 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1009 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
1010 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1011 * IPv6 omits the colons (01020304...0f)
1012 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1013 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
1014 * - 'I6c' for IPv6 addresses printed as specified by
1015 * http://tools.ietf.org/html/rfc5952
1016 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1017 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1018 * Options for %pU are:
1019 * b big endian lower case hex (default)
1020 * B big endian UPPER case hex
1021 * l little endian lower case hex
1022 * L little endian UPPER case hex
1023 * big endian output byte order is:
1024 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1025 * little endian output byte order is:
1026 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1027 * - 'V' For a struct va_format which contains a format string * and va_list *,
1028 * call vsnprintf(->format, *->va_list).
1029 * Implements a "recursive vsnprintf".
1030 * Do not use this feature without some mechanism to verify the
1031 * correctness of the format string and va_list arguments.
1032 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1033 * - 'NF' For a netdev_features_t
1034 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1035 * a certain separator (' ' by default):
1036 * C colon
1037 * D dash
1038 * N no separator
1039 * The maximum supported length is 64 bytes of the input. Consider
1040 * to use print_hex_dump() for the larger input.
1041 * - 'a' For a phys_addr_t type and its derivative types (passed by reference)
1042 *
1043 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1044 * function pointers are really function descriptors, which contain a
1045 * pointer to the real address.
1046 */
1047 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)1048 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1049 struct printf_spec spec)
1050 {
1051 int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1052
1053 if (!ptr && *fmt != 'K') {
1054 /*
1055 * Print (null) with the same width as a pointer so it makes
1056 * tabular output look nice.
1057 */
1058 if (spec.field_width == -1)
1059 spec.field_width = default_width;
1060 return string(buf, end, "(null)", spec);
1061 }
1062
1063 switch (*fmt) {
1064 case 'F':
1065 case 'f':
1066 ptr = dereference_function_descriptor(ptr);
1067 /* Fallthrough */
1068 case 'S':
1069 case 's':
1070 case 'B':
1071 return symbol_string(buf, end, ptr, spec, fmt);
1072 case 'R':
1073 case 'r':
1074 return resource_string(buf, end, ptr, spec, fmt);
1075 case 'h':
1076 return hex_string(buf, end, ptr, spec, fmt);
1077 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1078 case 'm': /* Contiguous: 000102030405 */
1079 /* [mM]F (FDDI) */
1080 /* [mM]R (Reverse order; Bluetooth) */
1081 return mac_address_string(buf, end, ptr, spec, fmt);
1082 case 'I': /* Formatted IP supported
1083 * 4: 1.2.3.4
1084 * 6: 0001:0203:...:0708
1085 * 6c: 1::708 or 1::1.2.3.4
1086 */
1087 case 'i': /* Contiguous:
1088 * 4: 001.002.003.004
1089 * 6: 000102...0f
1090 */
1091 switch (fmt[1]) {
1092 case '6':
1093 return ip6_addr_string(buf, end, ptr, spec, fmt);
1094 case '4':
1095 return ip4_addr_string(buf, end, ptr, spec, fmt);
1096 }
1097 break;
1098 case 'U':
1099 return uuid_string(buf, end, ptr, spec, fmt);
1100 case 'V':
1101 {
1102 va_list va;
1103
1104 va_copy(va, *((struct va_format *)ptr)->va);
1105 buf += vsnprintf(buf, end > buf ? end - buf : 0,
1106 ((struct va_format *)ptr)->fmt, va);
1107 va_end(va);
1108 return buf;
1109 }
1110 case 'K':
1111 /*
1112 * %pK cannot be used in IRQ context because its test
1113 * for CAP_SYSLOG would be meaningless.
1114 */
1115 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1116 in_nmi())) {
1117 if (spec.field_width == -1)
1118 spec.field_width = default_width;
1119 return string(buf, end, "pK-error", spec);
1120 }
1121 if (!((kptr_restrict == 0) ||
1122 (kptr_restrict == 1 &&
1123 has_capability_noaudit(current, CAP_SYSLOG))))
1124 ptr = NULL;
1125 break;
1126 case 'N':
1127 switch (fmt[1]) {
1128 case 'F':
1129 return netdev_feature_string(buf, end, ptr, spec);
1130 }
1131 break;
1132 case 'a':
1133 spec.flags |= SPECIAL | SMALL | ZEROPAD;
1134 spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1135 spec.base = 16;
1136 return number(buf, end,
1137 (unsigned long long) *((phys_addr_t *)ptr), spec);
1138 }
1139 spec.flags |= SMALL;
1140 if (spec.field_width == -1) {
1141 spec.field_width = default_width;
1142 spec.flags |= ZEROPAD;
1143 }
1144 spec.base = 16;
1145
1146 return number(buf, end, (unsigned long) ptr, spec);
1147 }
1148
1149 /*
1150 * Helper function to decode printf style format.
1151 * Each call decode a token from the format and return the
1152 * number of characters read (or likely the delta where it wants
1153 * to go on the next call).
1154 * The decoded token is returned through the parameters
1155 *
1156 * 'h', 'l', or 'L' for integer fields
1157 * 'z' support added 23/7/1999 S.H.
1158 * 'z' changed to 'Z' --davidm 1/25/99
1159 * 't' added for ptrdiff_t
1160 *
1161 * @fmt: the format string
1162 * @type of the token returned
1163 * @flags: various flags such as +, -, # tokens..
1164 * @field_width: overwritten width
1165 * @base: base of the number (octal, hex, ...)
1166 * @precision: precision of a number
1167 * @qualifier: qualifier of a number (long, size_t, ...)
1168 */
1169 static noinline_for_stack
format_decode(const char * fmt,struct printf_spec * spec)1170 int format_decode(const char *fmt, struct printf_spec *spec)
1171 {
1172 const char *start = fmt;
1173
1174 /* we finished early by reading the field width */
1175 if (spec->type == FORMAT_TYPE_WIDTH) {
1176 if (spec->field_width < 0) {
1177 spec->field_width = -spec->field_width;
1178 spec->flags |= LEFT;
1179 }
1180 spec->type = FORMAT_TYPE_NONE;
1181 goto precision;
1182 }
1183
1184 /* we finished early by reading the precision */
1185 if (spec->type == FORMAT_TYPE_PRECISION) {
1186 if (spec->precision < 0)
1187 spec->precision = 0;
1188
1189 spec->type = FORMAT_TYPE_NONE;
1190 goto qualifier;
1191 }
1192
1193 /* By default */
1194 spec->type = FORMAT_TYPE_NONE;
1195
1196 for (; *fmt ; ++fmt) {
1197 if (*fmt == '%')
1198 break;
1199 }
1200
1201 /* Return the current non-format string */
1202 if (fmt != start || !*fmt)
1203 return fmt - start;
1204
1205 /* Process flags */
1206 spec->flags = 0;
1207
1208 while (1) { /* this also skips first '%' */
1209 bool found = true;
1210
1211 ++fmt;
1212
1213 switch (*fmt) {
1214 case '-': spec->flags |= LEFT; break;
1215 case '+': spec->flags |= PLUS; break;
1216 case ' ': spec->flags |= SPACE; break;
1217 case '#': spec->flags |= SPECIAL; break;
1218 case '0': spec->flags |= ZEROPAD; break;
1219 default: found = false;
1220 }
1221
1222 if (!found)
1223 break;
1224 }
1225
1226 /* get field width */
1227 spec->field_width = -1;
1228
1229 if (isdigit(*fmt))
1230 spec->field_width = skip_atoi(&fmt);
1231 else if (*fmt == '*') {
1232 /* it's the next argument */
1233 spec->type = FORMAT_TYPE_WIDTH;
1234 return ++fmt - start;
1235 }
1236
1237 precision:
1238 /* get the precision */
1239 spec->precision = -1;
1240 if (*fmt == '.') {
1241 ++fmt;
1242 if (isdigit(*fmt)) {
1243 spec->precision = skip_atoi(&fmt);
1244 if (spec->precision < 0)
1245 spec->precision = 0;
1246 } else if (*fmt == '*') {
1247 /* it's the next argument */
1248 spec->type = FORMAT_TYPE_PRECISION;
1249 return ++fmt - start;
1250 }
1251 }
1252
1253 qualifier:
1254 /* get the conversion qualifier */
1255 spec->qualifier = -1;
1256 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1257 _tolower(*fmt) == 'z' || *fmt == 't') {
1258 spec->qualifier = *fmt++;
1259 if (unlikely(spec->qualifier == *fmt)) {
1260 if (spec->qualifier == 'l') {
1261 spec->qualifier = 'L';
1262 ++fmt;
1263 } else if (spec->qualifier == 'h') {
1264 spec->qualifier = 'H';
1265 ++fmt;
1266 }
1267 }
1268 }
1269
1270 /* default base */
1271 spec->base = 10;
1272 switch (*fmt) {
1273 case 'c':
1274 spec->type = FORMAT_TYPE_CHAR;
1275 return ++fmt - start;
1276
1277 case 's':
1278 spec->type = FORMAT_TYPE_STR;
1279 return ++fmt - start;
1280
1281 case 'p':
1282 spec->type = FORMAT_TYPE_PTR;
1283 return fmt - start;
1284 /* skip alnum */
1285
1286 case 'n':
1287 spec->type = FORMAT_TYPE_NRCHARS;
1288 return ++fmt - start;
1289
1290 case '%':
1291 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1292 return ++fmt - start;
1293
1294 /* integer number formats - set up the flags and "break" */
1295 case 'o':
1296 spec->base = 8;
1297 break;
1298
1299 case 'x':
1300 spec->flags |= SMALL;
1301
1302 case 'X':
1303 spec->base = 16;
1304 break;
1305
1306 case 'd':
1307 case 'i':
1308 spec->flags |= SIGN;
1309 case 'u':
1310 break;
1311
1312 default:
1313 spec->type = FORMAT_TYPE_INVALID;
1314 return fmt - start;
1315 }
1316
1317 if (spec->qualifier == 'L')
1318 spec->type = FORMAT_TYPE_LONG_LONG;
1319 else if (spec->qualifier == 'l') {
1320 if (spec->flags & SIGN)
1321 spec->type = FORMAT_TYPE_LONG;
1322 else
1323 spec->type = FORMAT_TYPE_ULONG;
1324 } else if (_tolower(spec->qualifier) == 'z') {
1325 spec->type = FORMAT_TYPE_SIZE_T;
1326 } else if (spec->qualifier == 't') {
1327 spec->type = FORMAT_TYPE_PTRDIFF;
1328 } else if (spec->qualifier == 'H') {
1329 if (spec->flags & SIGN)
1330 spec->type = FORMAT_TYPE_BYTE;
1331 else
1332 spec->type = FORMAT_TYPE_UBYTE;
1333 } else if (spec->qualifier == 'h') {
1334 if (spec->flags & SIGN)
1335 spec->type = FORMAT_TYPE_SHORT;
1336 else
1337 spec->type = FORMAT_TYPE_USHORT;
1338 } else {
1339 if (spec->flags & SIGN)
1340 spec->type = FORMAT_TYPE_INT;
1341 else
1342 spec->type = FORMAT_TYPE_UINT;
1343 }
1344
1345 return ++fmt - start;
1346 }
1347
1348 /**
1349 * vsnprintf - Format a string and place it in a buffer
1350 * @buf: The buffer to place the result into
1351 * @size: The size of the buffer, including the trailing null space
1352 * @fmt: The format string to use
1353 * @args: Arguments for the format string
1354 *
1355 * This function follows C99 vsnprintf, but has some extensions:
1356 * %pS output the name of a text symbol with offset
1357 * %ps output the name of a text symbol without offset
1358 * %pF output the name of a function pointer with its offset
1359 * %pf output the name of a function pointer without its offset
1360 * %pB output the name of a backtrace symbol with its offset
1361 * %pR output the address range in a struct resource with decoded flags
1362 * %pr output the address range in a struct resource with raw flags
1363 * %pM output a 6-byte MAC address with colons
1364 * %pMR output a 6-byte MAC address with colons in reversed order
1365 * %pMF output a 6-byte MAC address with dashes
1366 * %pm output a 6-byte MAC address without colons
1367 * %pmR output a 6-byte MAC address without colons in reversed order
1368 * %pI4 print an IPv4 address without leading zeros
1369 * %pi4 print an IPv4 address with leading zeros
1370 * %pI6 print an IPv6 address with colons
1371 * %pi6 print an IPv6 address without colons
1372 * %pI6c print an IPv6 address as specified by RFC 5952
1373 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1374 * case.
1375 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1376 * bytes of the input)
1377 * %n is ignored
1378 *
1379 * ** Please update Documentation/printk-formats.txt when making changes **
1380 *
1381 * The return value is the number of characters which would
1382 * be generated for the given input, excluding the trailing
1383 * '\0', as per ISO C99. If you want to have the exact
1384 * number of characters written into @buf as return value
1385 * (not including the trailing '\0'), use vscnprintf(). If the
1386 * return is greater than or equal to @size, the resulting
1387 * string is truncated.
1388 *
1389 * If you're not already dealing with a va_list consider using snprintf().
1390 */
vsnprintf(char * buf,size_t size,const char * fmt,va_list args)1391 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1392 {
1393 unsigned long long num;
1394 char *str, *end;
1395 struct printf_spec spec = {0};
1396
1397 /* Reject out-of-range values early. Large positive sizes are
1398 used for unknown buffer sizes. */
1399 if (WARN_ON_ONCE((int) size < 0))
1400 return 0;
1401
1402 str = buf;
1403 end = buf + size;
1404
1405 /* Make sure end is always >= buf */
1406 if (end < buf) {
1407 end = ((void *)-1);
1408 size = end - buf;
1409 }
1410
1411 while (*fmt) {
1412 const char *old_fmt = fmt;
1413 int read = format_decode(fmt, &spec);
1414
1415 fmt += read;
1416
1417 switch (spec.type) {
1418 case FORMAT_TYPE_NONE: {
1419 int copy = read;
1420 if (str < end) {
1421 if (copy > end - str)
1422 copy = end - str;
1423 memcpy(str, old_fmt, copy);
1424 }
1425 str += read;
1426 break;
1427 }
1428
1429 case FORMAT_TYPE_WIDTH:
1430 spec.field_width = va_arg(args, int);
1431 break;
1432
1433 case FORMAT_TYPE_PRECISION:
1434 spec.precision = va_arg(args, int);
1435 break;
1436
1437 case FORMAT_TYPE_CHAR: {
1438 char c;
1439
1440 if (!(spec.flags & LEFT)) {
1441 while (--spec.field_width > 0) {
1442 if (str < end)
1443 *str = ' ';
1444 ++str;
1445
1446 }
1447 }
1448 c = (unsigned char) va_arg(args, int);
1449 if (str < end)
1450 *str = c;
1451 ++str;
1452 while (--spec.field_width > 0) {
1453 if (str < end)
1454 *str = ' ';
1455 ++str;
1456 }
1457 break;
1458 }
1459
1460 case FORMAT_TYPE_STR:
1461 str = string(str, end, va_arg(args, char *), spec);
1462 break;
1463
1464 case FORMAT_TYPE_PTR:
1465 str = pointer(fmt+1, str, end, va_arg(args, void *),
1466 spec);
1467 while (isalnum(*fmt))
1468 fmt++;
1469 break;
1470
1471 case FORMAT_TYPE_PERCENT_CHAR:
1472 if (str < end)
1473 *str = '%';
1474 ++str;
1475 break;
1476
1477 case FORMAT_TYPE_INVALID:
1478 if (str < end)
1479 *str = '%';
1480 ++str;
1481 break;
1482
1483 case FORMAT_TYPE_NRCHARS: {
1484 u8 qualifier = spec.qualifier;
1485
1486 if (qualifier == 'l') {
1487 long *ip = va_arg(args, long *);
1488 *ip = (str - buf);
1489 } else if (_tolower(qualifier) == 'z') {
1490 size_t *ip = va_arg(args, size_t *);
1491 *ip = (str - buf);
1492 } else {
1493 int *ip = va_arg(args, int *);
1494 *ip = (str - buf);
1495 }
1496 break;
1497 }
1498
1499 default:
1500 switch (spec.type) {
1501 case FORMAT_TYPE_LONG_LONG:
1502 num = va_arg(args, long long);
1503 break;
1504 case FORMAT_TYPE_ULONG:
1505 num = va_arg(args, unsigned long);
1506 break;
1507 case FORMAT_TYPE_LONG:
1508 num = va_arg(args, long);
1509 break;
1510 case FORMAT_TYPE_SIZE_T:
1511 if (spec.flags & SIGN)
1512 num = va_arg(args, ssize_t);
1513 else
1514 num = va_arg(args, size_t);
1515 break;
1516 case FORMAT_TYPE_PTRDIFF:
1517 num = va_arg(args, ptrdiff_t);
1518 break;
1519 case FORMAT_TYPE_UBYTE:
1520 num = (unsigned char) va_arg(args, int);
1521 break;
1522 case FORMAT_TYPE_BYTE:
1523 num = (signed char) va_arg(args, int);
1524 break;
1525 case FORMAT_TYPE_USHORT:
1526 num = (unsigned short) va_arg(args, int);
1527 break;
1528 case FORMAT_TYPE_SHORT:
1529 num = (short) va_arg(args, int);
1530 break;
1531 case FORMAT_TYPE_INT:
1532 num = (int) va_arg(args, int);
1533 break;
1534 default:
1535 num = va_arg(args, unsigned int);
1536 }
1537
1538 str = number(str, end, num, spec);
1539 }
1540 }
1541
1542 if (size > 0) {
1543 if (str < end)
1544 *str = '\0';
1545 else
1546 end[-1] = '\0';
1547 }
1548
1549 /* the trailing null byte doesn't count towards the total */
1550 return str-buf;
1551
1552 }
1553 EXPORT_SYMBOL(vsnprintf);
1554
1555 /**
1556 * vscnprintf - Format a string and place it in a buffer
1557 * @buf: The buffer to place the result into
1558 * @size: The size of the buffer, including the trailing null space
1559 * @fmt: The format string to use
1560 * @args: Arguments for the format string
1561 *
1562 * The return value is the number of characters which have been written into
1563 * the @buf not including the trailing '\0'. If @size is == 0 the function
1564 * returns 0.
1565 *
1566 * If you're not already dealing with a va_list consider using scnprintf().
1567 *
1568 * See the vsnprintf() documentation for format string extensions over C99.
1569 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)1570 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1571 {
1572 int i;
1573
1574 i = vsnprintf(buf, size, fmt, args);
1575
1576 if (likely(i < size))
1577 return i;
1578 if (size != 0)
1579 return size - 1;
1580 return 0;
1581 }
1582 EXPORT_SYMBOL(vscnprintf);
1583
1584 /**
1585 * snprintf - Format a string and place it in a buffer
1586 * @buf: The buffer to place the result into
1587 * @size: The size of the buffer, including the trailing null space
1588 * @fmt: The format string to use
1589 * @...: Arguments for the format string
1590 *
1591 * The return value is the number of characters which would be
1592 * generated for the given input, excluding the trailing null,
1593 * as per ISO C99. If the return is greater than or equal to
1594 * @size, the resulting string is truncated.
1595 *
1596 * See the vsnprintf() documentation for format string extensions over C99.
1597 */
snprintf(char * buf,size_t size,const char * fmt,...)1598 int snprintf(char *buf, size_t size, const char *fmt, ...)
1599 {
1600 va_list args;
1601 int i;
1602
1603 va_start(args, fmt);
1604 i = vsnprintf(buf, size, fmt, args);
1605 va_end(args);
1606
1607 return i;
1608 }
1609 EXPORT_SYMBOL(snprintf);
1610
1611 /**
1612 * scnprintf - Format a string and place it in a buffer
1613 * @buf: The buffer to place the result into
1614 * @size: The size of the buffer, including the trailing null space
1615 * @fmt: The format string to use
1616 * @...: Arguments for the format string
1617 *
1618 * The return value is the number of characters written into @buf not including
1619 * the trailing '\0'. If @size is == 0 the function returns 0.
1620 */
1621
scnprintf(char * buf,size_t size,const char * fmt,...)1622 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1623 {
1624 va_list args;
1625 int i;
1626
1627 va_start(args, fmt);
1628 i = vscnprintf(buf, size, fmt, args);
1629 va_end(args);
1630
1631 return i;
1632 }
1633 EXPORT_SYMBOL(scnprintf);
1634
1635 /**
1636 * vsprintf - Format a string and place it in a buffer
1637 * @buf: The buffer to place the result into
1638 * @fmt: The format string to use
1639 * @args: Arguments for the format string
1640 *
1641 * The function returns the number of characters written
1642 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1643 * buffer overflows.
1644 *
1645 * If you're not already dealing with a va_list consider using sprintf().
1646 *
1647 * See the vsnprintf() documentation for format string extensions over C99.
1648 */
vsprintf(char * buf,const char * fmt,va_list args)1649 int vsprintf(char *buf, const char *fmt, va_list args)
1650 {
1651 return vsnprintf(buf, INT_MAX, fmt, args);
1652 }
1653 EXPORT_SYMBOL(vsprintf);
1654
1655 /**
1656 * sprintf - Format a string and place it in a buffer
1657 * @buf: The buffer to place the result into
1658 * @fmt: The format string to use
1659 * @...: Arguments for the format string
1660 *
1661 * The function returns the number of characters written
1662 * into @buf. Use snprintf() or scnprintf() in order to avoid
1663 * buffer overflows.
1664 *
1665 * See the vsnprintf() documentation for format string extensions over C99.
1666 */
sprintf(char * buf,const char * fmt,...)1667 int sprintf(char *buf, const char *fmt, ...)
1668 {
1669 va_list args;
1670 int i;
1671
1672 va_start(args, fmt);
1673 i = vsnprintf(buf, INT_MAX, fmt, args);
1674 va_end(args);
1675
1676 return i;
1677 }
1678 EXPORT_SYMBOL(sprintf);
1679
1680 #ifdef CONFIG_BINARY_PRINTF
1681 /*
1682 * bprintf service:
1683 * vbin_printf() - VA arguments to binary data
1684 * bstr_printf() - Binary data to text string
1685 */
1686
1687 /**
1688 * vbin_printf - Parse a format string and place args' binary value in a buffer
1689 * @bin_buf: The buffer to place args' binary value
1690 * @size: The size of the buffer(by words(32bits), not characters)
1691 * @fmt: The format string to use
1692 * @args: Arguments for the format string
1693 *
1694 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1695 * is skiped.
1696 *
1697 * The return value is the number of words(32bits) which would be generated for
1698 * the given input.
1699 *
1700 * NOTE:
1701 * If the return value is greater than @size, the resulting bin_buf is NOT
1702 * valid for bstr_printf().
1703 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt,va_list args)1704 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1705 {
1706 struct printf_spec spec = {0};
1707 char *str, *end;
1708
1709 str = (char *)bin_buf;
1710 end = (char *)(bin_buf + size);
1711
1712 #define save_arg(type) \
1713 do { \
1714 if (sizeof(type) == 8) { \
1715 unsigned long long value; \
1716 str = PTR_ALIGN(str, sizeof(u32)); \
1717 value = va_arg(args, unsigned long long); \
1718 if (str + sizeof(type) <= end) { \
1719 *(u32 *)str = *(u32 *)&value; \
1720 *(u32 *)(str + 4) = *((u32 *)&value + 1); \
1721 } \
1722 } else { \
1723 unsigned long value; \
1724 str = PTR_ALIGN(str, sizeof(type)); \
1725 value = va_arg(args, int); \
1726 if (str + sizeof(type) <= end) \
1727 *(typeof(type) *)str = (type)value; \
1728 } \
1729 str += sizeof(type); \
1730 } while (0)
1731
1732 while (*fmt) {
1733 int read = format_decode(fmt, &spec);
1734
1735 fmt += read;
1736
1737 switch (spec.type) {
1738 case FORMAT_TYPE_NONE:
1739 case FORMAT_TYPE_INVALID:
1740 case FORMAT_TYPE_PERCENT_CHAR:
1741 break;
1742
1743 case FORMAT_TYPE_WIDTH:
1744 case FORMAT_TYPE_PRECISION:
1745 save_arg(int);
1746 break;
1747
1748 case FORMAT_TYPE_CHAR:
1749 save_arg(char);
1750 break;
1751
1752 case FORMAT_TYPE_STR: {
1753 const char *save_str = va_arg(args, char *);
1754 size_t len;
1755
1756 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1757 || (unsigned long)save_str < PAGE_SIZE)
1758 save_str = "(null)";
1759 len = strlen(save_str) + 1;
1760 if (str + len < end)
1761 memcpy(str, save_str, len);
1762 str += len;
1763 break;
1764 }
1765
1766 case FORMAT_TYPE_PTR:
1767 save_arg(void *);
1768 /* skip all alphanumeric pointer suffixes */
1769 while (isalnum(*fmt))
1770 fmt++;
1771 break;
1772
1773 case FORMAT_TYPE_NRCHARS: {
1774 /* skip %n 's argument */
1775 u8 qualifier = spec.qualifier;
1776 void *skip_arg;
1777 if (qualifier == 'l')
1778 skip_arg = va_arg(args, long *);
1779 else if (_tolower(qualifier) == 'z')
1780 skip_arg = va_arg(args, size_t *);
1781 else
1782 skip_arg = va_arg(args, int *);
1783 break;
1784 }
1785
1786 default:
1787 switch (spec.type) {
1788
1789 case FORMAT_TYPE_LONG_LONG:
1790 save_arg(long long);
1791 break;
1792 case FORMAT_TYPE_ULONG:
1793 case FORMAT_TYPE_LONG:
1794 save_arg(unsigned long);
1795 break;
1796 case FORMAT_TYPE_SIZE_T:
1797 save_arg(size_t);
1798 break;
1799 case FORMAT_TYPE_PTRDIFF:
1800 save_arg(ptrdiff_t);
1801 break;
1802 case FORMAT_TYPE_UBYTE:
1803 case FORMAT_TYPE_BYTE:
1804 save_arg(char);
1805 break;
1806 case FORMAT_TYPE_USHORT:
1807 case FORMAT_TYPE_SHORT:
1808 save_arg(short);
1809 break;
1810 default:
1811 save_arg(int);
1812 }
1813 }
1814 }
1815
1816 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1817 #undef save_arg
1818 }
1819 EXPORT_SYMBOL_GPL(vbin_printf);
1820
1821 /**
1822 * bstr_printf - Format a string from binary arguments and place it in a buffer
1823 * @buf: The buffer to place the result into
1824 * @size: The size of the buffer, including the trailing null space
1825 * @fmt: The format string to use
1826 * @bin_buf: Binary arguments for the format string
1827 *
1828 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1829 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1830 * a binary buffer that generated by vbin_printf.
1831 *
1832 * The format follows C99 vsnprintf, but has some extensions:
1833 * see vsnprintf comment for details.
1834 *
1835 * The return value is the number of characters which would
1836 * be generated for the given input, excluding the trailing
1837 * '\0', as per ISO C99. If you want to have the exact
1838 * number of characters written into @buf as return value
1839 * (not including the trailing '\0'), use vscnprintf(). If the
1840 * return is greater than or equal to @size, the resulting
1841 * string is truncated.
1842 */
bstr_printf(char * buf,size_t size,const char * fmt,const u32 * bin_buf)1843 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1844 {
1845 struct printf_spec spec = {0};
1846 char *str, *end;
1847 const char *args = (const char *)bin_buf;
1848
1849 if (WARN_ON_ONCE((int) size < 0))
1850 return 0;
1851
1852 str = buf;
1853 end = buf + size;
1854
1855 #define get_arg(type) \
1856 ({ \
1857 typeof(type) value; \
1858 if (sizeof(type) == 8) { \
1859 args = PTR_ALIGN(args, sizeof(u32)); \
1860 *(u32 *)&value = *(u32 *)args; \
1861 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
1862 } else { \
1863 args = PTR_ALIGN(args, sizeof(type)); \
1864 value = *(typeof(type) *)args; \
1865 } \
1866 args += sizeof(type); \
1867 value; \
1868 })
1869
1870 /* Make sure end is always >= buf */
1871 if (end < buf) {
1872 end = ((void *)-1);
1873 size = end - buf;
1874 }
1875
1876 while (*fmt) {
1877 const char *old_fmt = fmt;
1878 int read = format_decode(fmt, &spec);
1879
1880 fmt += read;
1881
1882 switch (spec.type) {
1883 case FORMAT_TYPE_NONE: {
1884 int copy = read;
1885 if (str < end) {
1886 if (copy > end - str)
1887 copy = end - str;
1888 memcpy(str, old_fmt, copy);
1889 }
1890 str += read;
1891 break;
1892 }
1893
1894 case FORMAT_TYPE_WIDTH:
1895 spec.field_width = get_arg(int);
1896 break;
1897
1898 case FORMAT_TYPE_PRECISION:
1899 spec.precision = get_arg(int);
1900 break;
1901
1902 case FORMAT_TYPE_CHAR: {
1903 char c;
1904
1905 if (!(spec.flags & LEFT)) {
1906 while (--spec.field_width > 0) {
1907 if (str < end)
1908 *str = ' ';
1909 ++str;
1910 }
1911 }
1912 c = (unsigned char) get_arg(char);
1913 if (str < end)
1914 *str = c;
1915 ++str;
1916 while (--spec.field_width > 0) {
1917 if (str < end)
1918 *str = ' ';
1919 ++str;
1920 }
1921 break;
1922 }
1923
1924 case FORMAT_TYPE_STR: {
1925 const char *str_arg = args;
1926 args += strlen(str_arg) + 1;
1927 str = string(str, end, (char *)str_arg, spec);
1928 break;
1929 }
1930
1931 case FORMAT_TYPE_PTR:
1932 str = pointer(fmt+1, str, end, get_arg(void *), spec);
1933 while (isalnum(*fmt))
1934 fmt++;
1935 break;
1936
1937 case FORMAT_TYPE_PERCENT_CHAR:
1938 case FORMAT_TYPE_INVALID:
1939 if (str < end)
1940 *str = '%';
1941 ++str;
1942 break;
1943
1944 case FORMAT_TYPE_NRCHARS:
1945 /* skip */
1946 break;
1947
1948 default: {
1949 unsigned long long num;
1950
1951 switch (spec.type) {
1952
1953 case FORMAT_TYPE_LONG_LONG:
1954 num = get_arg(long long);
1955 break;
1956 case FORMAT_TYPE_ULONG:
1957 case FORMAT_TYPE_LONG:
1958 num = get_arg(unsigned long);
1959 break;
1960 case FORMAT_TYPE_SIZE_T:
1961 num = get_arg(size_t);
1962 break;
1963 case FORMAT_TYPE_PTRDIFF:
1964 num = get_arg(ptrdiff_t);
1965 break;
1966 case FORMAT_TYPE_UBYTE:
1967 num = get_arg(unsigned char);
1968 break;
1969 case FORMAT_TYPE_BYTE:
1970 num = get_arg(signed char);
1971 break;
1972 case FORMAT_TYPE_USHORT:
1973 num = get_arg(unsigned short);
1974 break;
1975 case FORMAT_TYPE_SHORT:
1976 num = get_arg(short);
1977 break;
1978 case FORMAT_TYPE_UINT:
1979 num = get_arg(unsigned int);
1980 break;
1981 default:
1982 num = get_arg(int);
1983 }
1984
1985 str = number(str, end, num, spec);
1986 } /* default: */
1987 } /* switch(spec.type) */
1988 } /* while(*fmt) */
1989
1990 if (size > 0) {
1991 if (str < end)
1992 *str = '\0';
1993 else
1994 end[-1] = '\0';
1995 }
1996
1997 #undef get_arg
1998
1999 /* the trailing null byte doesn't count towards the total */
2000 return str - buf;
2001 }
2002 EXPORT_SYMBOL_GPL(bstr_printf);
2003
2004 /**
2005 * bprintf - Parse a format string and place args' binary value in a buffer
2006 * @bin_buf: The buffer to place args' binary value
2007 * @size: The size of the buffer(by words(32bits), not characters)
2008 * @fmt: The format string to use
2009 * @...: Arguments for the format string
2010 *
2011 * The function returns the number of words(u32) written
2012 * into @bin_buf.
2013 */
bprintf(u32 * bin_buf,size_t size,const char * fmt,...)2014 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2015 {
2016 va_list args;
2017 int ret;
2018
2019 va_start(args, fmt);
2020 ret = vbin_printf(bin_buf, size, fmt, args);
2021 va_end(args);
2022
2023 return ret;
2024 }
2025 EXPORT_SYMBOL_GPL(bprintf);
2026
2027 #endif /* CONFIG_BINARY_PRINTF */
2028
2029 /**
2030 * vsscanf - Unformat a buffer into a list of arguments
2031 * @buf: input buffer
2032 * @fmt: format of buffer
2033 * @args: arguments
2034 */
vsscanf(const char * buf,const char * fmt,va_list args)2035 int vsscanf(const char *buf, const char *fmt, va_list args)
2036 {
2037 const char *str = buf;
2038 char *next;
2039 char digit;
2040 int num = 0;
2041 u8 qualifier;
2042 unsigned int base;
2043 union {
2044 long long s;
2045 unsigned long long u;
2046 } val;
2047 s16 field_width;
2048 bool is_sign;
2049
2050 while (*fmt) {
2051 /* skip any white space in format */
2052 /* white space in format matchs any amount of
2053 * white space, including none, in the input.
2054 */
2055 if (isspace(*fmt)) {
2056 fmt = skip_spaces(++fmt);
2057 str = skip_spaces(str);
2058 }
2059
2060 /* anything that is not a conversion must match exactly */
2061 if (*fmt != '%' && *fmt) {
2062 if (*fmt++ != *str++)
2063 break;
2064 continue;
2065 }
2066
2067 if (!*fmt)
2068 break;
2069 ++fmt;
2070
2071 /* skip this conversion.
2072 * advance both strings to next white space
2073 */
2074 if (*fmt == '*') {
2075 if (!*str)
2076 break;
2077 while (!isspace(*fmt) && *fmt != '%' && *fmt)
2078 fmt++;
2079 while (!isspace(*str) && *str)
2080 str++;
2081 continue;
2082 }
2083
2084 /* get field width */
2085 field_width = -1;
2086 if (isdigit(*fmt)) {
2087 field_width = skip_atoi(&fmt);
2088 if (field_width <= 0)
2089 break;
2090 }
2091
2092 /* get conversion qualifier */
2093 qualifier = -1;
2094 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2095 _tolower(*fmt) == 'z') {
2096 qualifier = *fmt++;
2097 if (unlikely(qualifier == *fmt)) {
2098 if (qualifier == 'h') {
2099 qualifier = 'H';
2100 fmt++;
2101 } else if (qualifier == 'l') {
2102 qualifier = 'L';
2103 fmt++;
2104 }
2105 }
2106 }
2107
2108 if (!*fmt)
2109 break;
2110
2111 if (*fmt == 'n') {
2112 /* return number of characters read so far */
2113 *va_arg(args, int *) = str - buf;
2114 ++fmt;
2115 continue;
2116 }
2117
2118 if (!*str)
2119 break;
2120
2121 base = 10;
2122 is_sign = 0;
2123
2124 switch (*fmt++) {
2125 case 'c':
2126 {
2127 char *s = (char *)va_arg(args, char*);
2128 if (field_width == -1)
2129 field_width = 1;
2130 do {
2131 *s++ = *str++;
2132 } while (--field_width > 0 && *str);
2133 num++;
2134 }
2135 continue;
2136 case 's':
2137 {
2138 char *s = (char *)va_arg(args, char *);
2139 if (field_width == -1)
2140 field_width = SHRT_MAX;
2141 /* first, skip leading white space in buffer */
2142 str = skip_spaces(str);
2143
2144 /* now copy until next white space */
2145 while (*str && !isspace(*str) && field_width--)
2146 *s++ = *str++;
2147 *s = '\0';
2148 num++;
2149 }
2150 continue;
2151 case 'o':
2152 base = 8;
2153 break;
2154 case 'x':
2155 case 'X':
2156 base = 16;
2157 break;
2158 case 'i':
2159 base = 0;
2160 case 'd':
2161 is_sign = 1;
2162 case 'u':
2163 break;
2164 case '%':
2165 /* looking for '%' in str */
2166 if (*str++ != '%')
2167 return num;
2168 continue;
2169 default:
2170 /* invalid format; stop here */
2171 return num;
2172 }
2173
2174 /* have some sort of integer conversion.
2175 * first, skip white space in buffer.
2176 */
2177 str = skip_spaces(str);
2178
2179 digit = *str;
2180 if (is_sign && digit == '-')
2181 digit = *(str + 1);
2182
2183 if (!digit
2184 || (base == 16 && !isxdigit(digit))
2185 || (base == 10 && !isdigit(digit))
2186 || (base == 8 && (!isdigit(digit) || digit > '7'))
2187 || (base == 0 && !isdigit(digit)))
2188 break;
2189
2190 if (is_sign)
2191 val.s = qualifier != 'L' ?
2192 simple_strtol(str, &next, base) :
2193 simple_strtoll(str, &next, base);
2194 else
2195 val.u = qualifier != 'L' ?
2196 simple_strtoul(str, &next, base) :
2197 simple_strtoull(str, &next, base);
2198
2199 if (field_width > 0 && next - str > field_width) {
2200 if (base == 0)
2201 _parse_integer_fixup_radix(str, &base);
2202 while (next - str > field_width) {
2203 if (is_sign)
2204 val.s = div_s64(val.s, base);
2205 else
2206 val.u = div_u64(val.u, base);
2207 --next;
2208 }
2209 }
2210
2211 switch (qualifier) {
2212 case 'H': /* that's 'hh' in format */
2213 if (is_sign)
2214 *va_arg(args, signed char *) = val.s;
2215 else
2216 *va_arg(args, unsigned char *) = val.u;
2217 break;
2218 case 'h':
2219 if (is_sign)
2220 *va_arg(args, short *) = val.s;
2221 else
2222 *va_arg(args, unsigned short *) = val.u;
2223 break;
2224 case 'l':
2225 if (is_sign)
2226 *va_arg(args, long *) = val.s;
2227 else
2228 *va_arg(args, unsigned long *) = val.u;
2229 break;
2230 case 'L':
2231 if (is_sign)
2232 *va_arg(args, long long *) = val.s;
2233 else
2234 *va_arg(args, unsigned long long *) = val.u;
2235 break;
2236 case 'Z':
2237 case 'z':
2238 *va_arg(args, size_t *) = val.u;
2239 break;
2240 default:
2241 if (is_sign)
2242 *va_arg(args, int *) = val.s;
2243 else
2244 *va_arg(args, unsigned int *) = val.u;
2245 break;
2246 }
2247 num++;
2248
2249 if (!next)
2250 break;
2251 str = next;
2252 }
2253
2254 return num;
2255 }
2256 EXPORT_SYMBOL(vsscanf);
2257
2258 /**
2259 * sscanf - Unformat a buffer into a list of arguments
2260 * @buf: input buffer
2261 * @fmt: formatting of buffer
2262 * @...: resulting arguments
2263 */
sscanf(const char * buf,const char * fmt,...)2264 int sscanf(const char *buf, const char *fmt, ...)
2265 {
2266 va_list args;
2267 int i;
2268
2269 va_start(args, fmt);
2270 i = vsscanf(buf, fmt, args);
2271 va_end(args);
2272
2273 return i;
2274 }
2275 EXPORT_SYMBOL(sscanf);
2276