hyperv: Add processing of MTU reduced by the host
[linux/fpc-iii.git] / lib / vsprintf.c
blobec337f64f52ddada251c9126561e5e38a38093e5
1 /*
2 * linux/lib/vsprintf.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8 /*
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
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
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 <linux/dcache.h>
30 #include <linux/cred.h>
31 #include <net/addrconf.h>
33 #include <asm/page.h> /* for PAGE_SIZE */
34 #include <asm/sections.h> /* for dereference_function_descriptor() */
36 #include <linux/string_helpers.h>
37 #include "kstrtox.h"
39 /**
40 * simple_strtoull - convert a string to an unsigned long long
41 * @cp: The start of the string
42 * @endp: A pointer to the end of the parsed string will be placed here
43 * @base: The number base to use
45 * This function is obsolete. Please use kstrtoull instead.
47 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
49 unsigned long long result;
50 unsigned int rv;
52 cp = _parse_integer_fixup_radix(cp, &base);
53 rv = _parse_integer(cp, base, &result);
54 /* FIXME */
55 cp += (rv & ~KSTRTOX_OVERFLOW);
57 if (endp)
58 *endp = (char *)cp;
60 return result;
62 EXPORT_SYMBOL(simple_strtoull);
64 /**
65 * simple_strtoul - convert a string to an unsigned long
66 * @cp: The start of the string
67 * @endp: A pointer to the end of the parsed string will be placed here
68 * @base: The number base to use
70 * This function is obsolete. Please use kstrtoul instead.
72 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
74 return simple_strtoull(cp, endp, base);
76 EXPORT_SYMBOL(simple_strtoul);
78 /**
79 * simple_strtol - convert a string to a signed long
80 * @cp: The start of the string
81 * @endp: A pointer to the end of the parsed string will be placed here
82 * @base: The number base to use
84 * This function is obsolete. Please use kstrtol instead.
86 long simple_strtol(const char *cp, char **endp, unsigned int base)
88 if (*cp == '-')
89 return -simple_strtoul(cp + 1, endp, base);
91 return simple_strtoul(cp, endp, base);
93 EXPORT_SYMBOL(simple_strtol);
95 /**
96 * simple_strtoll - convert a string to a signed long long
97 * @cp: The start of the string
98 * @endp: A pointer to the end of the parsed string will be placed here
99 * @base: The number base to use
101 * This function is obsolete. Please use kstrtoll instead.
103 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
105 if (*cp == '-')
106 return -simple_strtoull(cp + 1, endp, base);
108 return simple_strtoull(cp, endp, base);
110 EXPORT_SYMBOL(simple_strtoll);
112 static noinline_for_stack
113 int skip_atoi(const char **s)
115 int i = 0;
117 while (isdigit(**s))
118 i = i*10 + *((*s)++) - '0';
120 return i;
123 /* Decimal conversion is by far the most typical, and is used
124 * for /proc and /sys data. This directly impacts e.g. top performance
125 * with many processes running. We optimize it for speed
126 * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
127 * (with permission from the author, Douglas W. Jones).
130 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
131 /* Formats correctly any integer in [0, 999999999] */
132 static noinline_for_stack
133 char *put_dec_full9(char *buf, unsigned q)
135 unsigned r;
138 * Possible ways to approx. divide by 10
139 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
140 * (x * 0xcccd) >> 19 x < 81920 (x < 262149 when 64-bit mul)
141 * (x * 0x6667) >> 18 x < 43699
142 * (x * 0x3334) >> 17 x < 16389
143 * (x * 0x199a) >> 16 x < 16389
144 * (x * 0x0ccd) >> 15 x < 16389
145 * (x * 0x0667) >> 14 x < 2739
146 * (x * 0x0334) >> 13 x < 1029
147 * (x * 0x019a) >> 12 x < 1029
148 * (x * 0x00cd) >> 11 x < 1029 shorter code than * 0x67 (on i386)
149 * (x * 0x0067) >> 10 x < 179
150 * (x * 0x0034) >> 9 x < 69 same
151 * (x * 0x001a) >> 8 x < 69 same
152 * (x * 0x000d) >> 7 x < 69 same, shortest code (on i386)
153 * (x * 0x0007) >> 6 x < 19
154 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
156 r = (q * (uint64_t)0x1999999a) >> 32;
157 *buf++ = (q - 10 * r) + '0'; /* 1 */
158 q = (r * (uint64_t)0x1999999a) >> 32;
159 *buf++ = (r - 10 * q) + '0'; /* 2 */
160 r = (q * (uint64_t)0x1999999a) >> 32;
161 *buf++ = (q - 10 * r) + '0'; /* 3 */
162 q = (r * (uint64_t)0x1999999a) >> 32;
163 *buf++ = (r - 10 * q) + '0'; /* 4 */
164 r = (q * (uint64_t)0x1999999a) >> 32;
165 *buf++ = (q - 10 * r) + '0'; /* 5 */
166 /* Now value is under 10000, can avoid 64-bit multiply */
167 q = (r * 0x199a) >> 16;
168 *buf++ = (r - 10 * q) + '0'; /* 6 */
169 r = (q * 0xcd) >> 11;
170 *buf++ = (q - 10 * r) + '0'; /* 7 */
171 q = (r * 0xcd) >> 11;
172 *buf++ = (r - 10 * q) + '0'; /* 8 */
173 *buf++ = q + '0'; /* 9 */
174 return buf;
176 #endif
178 /* Similar to above but do not pad with zeros.
179 * Code can be easily arranged to print 9 digits too, but our callers
180 * always call put_dec_full9() instead when the number has 9 decimal digits.
182 static noinline_for_stack
183 char *put_dec_trunc8(char *buf, unsigned r)
185 unsigned q;
187 /* Copy of previous function's body with added early returns */
188 while (r >= 10000) {
189 q = r + '0';
190 r = (r * (uint64_t)0x1999999a) >> 32;
191 *buf++ = q - 10*r;
194 q = (r * 0x199a) >> 16; /* r <= 9999 */
195 *buf++ = (r - 10 * q) + '0';
196 if (q == 0)
197 return buf;
198 r = (q * 0xcd) >> 11; /* q <= 999 */
199 *buf++ = (q - 10 * r) + '0';
200 if (r == 0)
201 return buf;
202 q = (r * 0xcd) >> 11; /* r <= 99 */
203 *buf++ = (r - 10 * q) + '0';
204 if (q == 0)
205 return buf;
206 *buf++ = q + '0'; /* q <= 9 */
207 return buf;
210 /* There are two algorithms to print larger numbers.
211 * One is generic: divide by 1000000000 and repeatedly print
212 * groups of (up to) 9 digits. It's conceptually simple,
213 * but requires a (unsigned long long) / 1000000000 division.
215 * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
216 * manipulates them cleverly and generates groups of 4 decimal digits.
217 * It so happens that it does NOT require long long division.
219 * If long is > 32 bits, division of 64-bit values is relatively easy,
220 * and we will use the first algorithm.
221 * If long long is > 64 bits (strange architecture with VERY large long long),
222 * second algorithm can't be used, and we again use the first one.
224 * Else (if long is 32 bits and long long is 64 bits) we use second one.
227 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
229 /* First algorithm: generic */
231 static
232 char *put_dec(char *buf, unsigned long long n)
234 if (n >= 100*1000*1000) {
235 while (n >= 1000*1000*1000)
236 buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
237 if (n >= 100*1000*1000)
238 return put_dec_full9(buf, n);
240 return put_dec_trunc8(buf, n);
243 #else
245 /* Second algorithm: valid only for 64-bit long longs */
247 /* See comment in put_dec_full9 for choice of constants */
248 static noinline_for_stack
249 void put_dec_full4(char *buf, unsigned q)
251 unsigned r;
252 r = (q * 0xccd) >> 15;
253 buf[0] = (q - 10 * r) + '0';
254 q = (r * 0xcd) >> 11;
255 buf[1] = (r - 10 * q) + '0';
256 r = (q * 0xcd) >> 11;
257 buf[2] = (q - 10 * r) + '0';
258 buf[3] = r + '0';
262 * Call put_dec_full4 on x % 10000, return x / 10000.
263 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
264 * holds for all x < 1,128,869,999. The largest value this
265 * helper will ever be asked to convert is 1,125,520,955.
266 * (d1 in the put_dec code, assuming n is all-ones).
268 static
269 unsigned put_dec_helper4(char *buf, unsigned x)
271 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
273 put_dec_full4(buf, x - q * 10000);
274 return q;
277 /* Based on code by Douglas W. Jones found at
278 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
279 * (with permission from the author).
280 * Performs no 64-bit division and hence should be fast on 32-bit machines.
282 static
283 char *put_dec(char *buf, unsigned long long n)
285 uint32_t d3, d2, d1, q, h;
287 if (n < 100*1000*1000)
288 return put_dec_trunc8(buf, n);
290 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
291 h = (n >> 32);
292 d2 = (h ) & 0xffff;
293 d3 = (h >> 16); /* implicit "& 0xffff" */
295 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
296 q = put_dec_helper4(buf, q);
298 q += 7671 * d3 + 9496 * d2 + 6 * d1;
299 q = put_dec_helper4(buf+4, q);
301 q += 4749 * d3 + 42 * d2;
302 q = put_dec_helper4(buf+8, q);
304 q += 281 * d3;
305 buf += 12;
306 if (q)
307 buf = put_dec_trunc8(buf, q);
308 else while (buf[-1] == '0')
309 --buf;
311 return buf;
314 #endif
317 * Convert passed number to decimal string.
318 * Returns the length of string. On buffer overflow, returns 0.
320 * If speed is not important, use snprintf(). It's easy to read the code.
322 int num_to_str(char *buf, int size, unsigned long long num)
324 char tmp[sizeof(num) * 3];
325 int idx, len;
327 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
328 if (num <= 9) {
329 tmp[0] = '0' + num;
330 len = 1;
331 } else {
332 len = put_dec(tmp, num) - tmp;
335 if (len > size)
336 return 0;
337 for (idx = 0; idx < len; ++idx)
338 buf[idx] = tmp[len - idx - 1];
339 return len;
342 #define ZEROPAD 1 /* pad with zero */
343 #define SIGN 2 /* unsigned/signed long */
344 #define PLUS 4 /* show plus */
345 #define SPACE 8 /* space if plus */
346 #define LEFT 16 /* left justified */
347 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
348 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
350 enum format_type {
351 FORMAT_TYPE_NONE, /* Just a string part */
352 FORMAT_TYPE_WIDTH,
353 FORMAT_TYPE_PRECISION,
354 FORMAT_TYPE_CHAR,
355 FORMAT_TYPE_STR,
356 FORMAT_TYPE_PTR,
357 FORMAT_TYPE_PERCENT_CHAR,
358 FORMAT_TYPE_INVALID,
359 FORMAT_TYPE_LONG_LONG,
360 FORMAT_TYPE_ULONG,
361 FORMAT_TYPE_LONG,
362 FORMAT_TYPE_UBYTE,
363 FORMAT_TYPE_BYTE,
364 FORMAT_TYPE_USHORT,
365 FORMAT_TYPE_SHORT,
366 FORMAT_TYPE_UINT,
367 FORMAT_TYPE_INT,
368 FORMAT_TYPE_SIZE_T,
369 FORMAT_TYPE_PTRDIFF
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 */
381 static noinline_for_stack
382 char *number(char *buf, char *end, unsigned long long num,
383 struct printf_spec spec)
385 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
386 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
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;
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--;
414 if (need_pfx) {
415 if (spec.base == 16)
416 spec.field_width -= 2;
417 else if (!is_zero)
418 spec.field_width--;
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);
430 else if (spec.base != 10) { /* 8 or 16 */
431 int mask = spec.base - 1;
432 int shift = 3;
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;
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;
456 /* sign */
457 if (sign) {
458 if (buf < end)
459 *buf = sign;
460 ++buf;
462 /* "0x" / "0" prefix */
463 if (need_pfx) {
464 if (spec.base == 16 || !is_zero) {
465 if (buf < end)
466 *buf = '0';
467 ++buf;
469 if (spec.base == 16) {
470 if (buf < end)
471 *buf = ('X' | locase);
472 ++buf;
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;
484 /* hmm even more zero padding? */
485 while (i <= --spec.precision) {
486 if (buf < end)
487 *buf = '0';
488 ++buf;
490 /* actual digits of result */
491 while (--i >= 0) {
492 if (buf < end)
493 *buf = tmp[i];
494 ++buf;
496 /* trailing space padding */
497 while (--spec.field_width >= 0) {
498 if (buf < end)
499 *buf = ' ';
500 ++buf;
503 return buf;
506 static noinline_for_stack
507 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
509 int len, i;
511 if ((unsigned long)s < PAGE_SIZE)
512 s = "(null)";
514 len = strnlen(s, spec.precision);
516 if (!(spec.flags & LEFT)) {
517 while (len < spec.field_width--) {
518 if (buf < end)
519 *buf = ' ';
520 ++buf;
523 for (i = 0; i < len; ++i) {
524 if (buf < end)
525 *buf = *s;
526 ++buf; ++s;
528 while (len < spec.field_width--) {
529 if (buf < end)
530 *buf = ' ';
531 ++buf;
534 return buf;
537 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
539 size_t size;
540 if (buf >= end) /* nowhere to put anything */
541 return;
542 size = end - buf;
543 if (size <= spaces) {
544 memset(buf, ' ', size);
545 return;
547 if (len) {
548 if (len > size - spaces)
549 len = size - spaces;
550 memmove(buf + spaces, buf, len);
552 memset(buf, ' ', spaces);
555 static noinline_for_stack
556 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
557 const char *fmt)
559 const char *array[4], *s;
560 const struct dentry *p;
561 int depth;
562 int i, n;
564 switch (fmt[1]) {
565 case '2': case '3': case '4':
566 depth = fmt[1] - '0';
567 break;
568 default:
569 depth = 1;
572 rcu_read_lock();
573 for (i = 0; i < depth; i++, d = p) {
574 p = ACCESS_ONCE(d->d_parent);
575 array[i] = ACCESS_ONCE(d->d_name.name);
576 if (p == d) {
577 if (i)
578 array[i] = "";
579 i++;
580 break;
583 s = array[--i];
584 for (n = 0; n != spec.precision; n++, buf++) {
585 char c = *s++;
586 if (!c) {
587 if (!i)
588 break;
589 c = '/';
590 s = array[--i];
592 if (buf < end)
593 *buf = c;
595 rcu_read_unlock();
596 if (n < spec.field_width) {
597 /* we want to pad the sucker */
598 unsigned spaces = spec.field_width - n;
599 if (!(spec.flags & LEFT)) {
600 widen(buf - n, end, n, spaces);
601 return buf + spaces;
603 while (spaces--) {
604 if (buf < end)
605 *buf = ' ';
606 ++buf;
609 return buf;
612 static noinline_for_stack
613 char *symbol_string(char *buf, char *end, void *ptr,
614 struct printf_spec spec, const char *fmt)
616 unsigned long value;
617 #ifdef CONFIG_KALLSYMS
618 char sym[KSYM_SYMBOL_LEN];
619 #endif
621 if (fmt[1] == 'R')
622 ptr = __builtin_extract_return_addr(ptr);
623 value = (unsigned long)ptr;
625 #ifdef CONFIG_KALLSYMS
626 if (*fmt == 'B')
627 sprint_backtrace(sym, value);
628 else if (*fmt != 'f' && *fmt != 's')
629 sprint_symbol(sym, value);
630 else
631 sprint_symbol_no_offset(sym, value);
633 return string(buf, end, sym, spec);
634 #else
635 spec.field_width = 2 * sizeof(void *);
636 spec.flags |= SPECIAL | SMALL | ZEROPAD;
637 spec.base = 16;
639 return number(buf, end, value, spec);
640 #endif
643 static noinline_for_stack
644 char *resource_string(char *buf, char *end, struct resource *res,
645 struct printf_spec spec, const char *fmt)
647 #ifndef IO_RSRC_PRINTK_SIZE
648 #define IO_RSRC_PRINTK_SIZE 6
649 #endif
651 #ifndef MEM_RSRC_PRINTK_SIZE
652 #define MEM_RSRC_PRINTK_SIZE 10
653 #endif
654 static const struct printf_spec io_spec = {
655 .base = 16,
656 .field_width = IO_RSRC_PRINTK_SIZE,
657 .precision = -1,
658 .flags = SPECIAL | SMALL | ZEROPAD,
660 static const struct printf_spec mem_spec = {
661 .base = 16,
662 .field_width = MEM_RSRC_PRINTK_SIZE,
663 .precision = -1,
664 .flags = SPECIAL | SMALL | ZEROPAD,
666 static const struct printf_spec bus_spec = {
667 .base = 16,
668 .field_width = 2,
669 .precision = -1,
670 .flags = SMALL | ZEROPAD,
672 static const struct printf_spec dec_spec = {
673 .base = 10,
674 .precision = -1,
675 .flags = 0,
677 static const struct printf_spec str_spec = {
678 .field_width = -1,
679 .precision = 10,
680 .flags = LEFT,
682 static const struct printf_spec flag_spec = {
683 .base = 16,
684 .precision = -1,
685 .flags = SPECIAL | SMALL,
688 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
689 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
690 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
691 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
692 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
693 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
694 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
695 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
697 char *p = sym, *pend = sym + sizeof(sym);
698 int decode = (fmt[0] == 'R') ? 1 : 0;
699 const struct printf_spec *specp;
701 *p++ = '[';
702 if (res->flags & IORESOURCE_IO) {
703 p = string(p, pend, "io ", str_spec);
704 specp = &io_spec;
705 } else if (res->flags & IORESOURCE_MEM) {
706 p = string(p, pend, "mem ", str_spec);
707 specp = &mem_spec;
708 } else if (res->flags & IORESOURCE_IRQ) {
709 p = string(p, pend, "irq ", str_spec);
710 specp = &dec_spec;
711 } else if (res->flags & IORESOURCE_DMA) {
712 p = string(p, pend, "dma ", str_spec);
713 specp = &dec_spec;
714 } else if (res->flags & IORESOURCE_BUS) {
715 p = string(p, pend, "bus ", str_spec);
716 specp = &bus_spec;
717 } else {
718 p = string(p, pend, "??? ", str_spec);
719 specp = &mem_spec;
720 decode = 0;
722 if (decode && res->flags & IORESOURCE_UNSET) {
723 p = string(p, pend, "size ", str_spec);
724 p = number(p, pend, resource_size(res), *specp);
725 } else {
726 p = number(p, pend, res->start, *specp);
727 if (res->start != res->end) {
728 *p++ = '-';
729 p = number(p, pend, res->end, *specp);
732 if (decode) {
733 if (res->flags & IORESOURCE_MEM_64)
734 p = string(p, pend, " 64bit", str_spec);
735 if (res->flags & IORESOURCE_PREFETCH)
736 p = string(p, pend, " pref", str_spec);
737 if (res->flags & IORESOURCE_WINDOW)
738 p = string(p, pend, " window", str_spec);
739 if (res->flags & IORESOURCE_DISABLED)
740 p = string(p, pend, " disabled", str_spec);
741 } else {
742 p = string(p, pend, " flags ", str_spec);
743 p = number(p, pend, res->flags, flag_spec);
745 *p++ = ']';
746 *p = '\0';
748 return string(buf, end, sym, spec);
751 static noinline_for_stack
752 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
753 const char *fmt)
755 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
756 negative value, fallback to the default */
757 char separator;
759 if (spec.field_width == 0)
760 /* nothing to print */
761 return buf;
763 if (ZERO_OR_NULL_PTR(addr))
764 /* NULL pointer */
765 return string(buf, end, NULL, spec);
767 switch (fmt[1]) {
768 case 'C':
769 separator = ':';
770 break;
771 case 'D':
772 separator = '-';
773 break;
774 case 'N':
775 separator = 0;
776 break;
777 default:
778 separator = ' ';
779 break;
782 if (spec.field_width > 0)
783 len = min_t(int, spec.field_width, 64);
785 for (i = 0; i < len && buf < end - 1; i++) {
786 buf = hex_byte_pack(buf, addr[i]);
788 if (buf < end && separator && i != len - 1)
789 *buf++ = separator;
792 return buf;
795 static noinline_for_stack
796 char *mac_address_string(char *buf, char *end, u8 *addr,
797 struct printf_spec spec, const char *fmt)
799 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
800 char *p = mac_addr;
801 int i;
802 char separator;
803 bool reversed = false;
805 switch (fmt[1]) {
806 case 'F':
807 separator = '-';
808 break;
810 case 'R':
811 reversed = true;
812 /* fall through */
814 default:
815 separator = ':';
816 break;
819 for (i = 0; i < 6; i++) {
820 if (reversed)
821 p = hex_byte_pack(p, addr[5 - i]);
822 else
823 p = hex_byte_pack(p, addr[i]);
825 if (fmt[0] == 'M' && i != 5)
826 *p++ = separator;
828 *p = '\0';
830 return string(buf, end, mac_addr, spec);
833 static noinline_for_stack
834 char *ip4_string(char *p, const u8 *addr, const char *fmt)
836 int i;
837 bool leading_zeros = (fmt[0] == 'i');
838 int index;
839 int step;
841 switch (fmt[2]) {
842 case 'h':
843 #ifdef __BIG_ENDIAN
844 index = 0;
845 step = 1;
846 #else
847 index = 3;
848 step = -1;
849 #endif
850 break;
851 case 'l':
852 index = 3;
853 step = -1;
854 break;
855 case 'n':
856 case 'b':
857 default:
858 index = 0;
859 step = 1;
860 break;
862 for (i = 0; i < 4; i++) {
863 char temp[3]; /* hold each IP quad in reverse order */
864 int digits = put_dec_trunc8(temp, addr[index]) - temp;
865 if (leading_zeros) {
866 if (digits < 3)
867 *p++ = '0';
868 if (digits < 2)
869 *p++ = '0';
871 /* reverse the digits in the quad */
872 while (digits--)
873 *p++ = temp[digits];
874 if (i < 3)
875 *p++ = '.';
876 index += step;
878 *p = '\0';
880 return p;
883 static noinline_for_stack
884 char *ip6_compressed_string(char *p, const char *addr)
886 int i, j, range;
887 unsigned char zerolength[8];
888 int longest = 1;
889 int colonpos = -1;
890 u16 word;
891 u8 hi, lo;
892 bool needcolon = false;
893 bool useIPv4;
894 struct in6_addr in6;
896 memcpy(&in6, addr, sizeof(struct in6_addr));
898 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
900 memset(zerolength, 0, sizeof(zerolength));
902 if (useIPv4)
903 range = 6;
904 else
905 range = 8;
907 /* find position of longest 0 run */
908 for (i = 0; i < range; i++) {
909 for (j = i; j < range; j++) {
910 if (in6.s6_addr16[j] != 0)
911 break;
912 zerolength[i]++;
915 for (i = 0; i < range; i++) {
916 if (zerolength[i] > longest) {
917 longest = zerolength[i];
918 colonpos = i;
921 if (longest == 1) /* don't compress a single 0 */
922 colonpos = -1;
924 /* emit address */
925 for (i = 0; i < range; i++) {
926 if (i == colonpos) {
927 if (needcolon || i == 0)
928 *p++ = ':';
929 *p++ = ':';
930 needcolon = false;
931 i += longest - 1;
932 continue;
934 if (needcolon) {
935 *p++ = ':';
936 needcolon = false;
938 /* hex u16 without leading 0s */
939 word = ntohs(in6.s6_addr16[i]);
940 hi = word >> 8;
941 lo = word & 0xff;
942 if (hi) {
943 if (hi > 0x0f)
944 p = hex_byte_pack(p, hi);
945 else
946 *p++ = hex_asc_lo(hi);
947 p = hex_byte_pack(p, lo);
949 else if (lo > 0x0f)
950 p = hex_byte_pack(p, lo);
951 else
952 *p++ = hex_asc_lo(lo);
953 needcolon = true;
956 if (useIPv4) {
957 if (needcolon)
958 *p++ = ':';
959 p = ip4_string(p, &in6.s6_addr[12], "I4");
961 *p = '\0';
963 return p;
966 static noinline_for_stack
967 char *ip6_string(char *p, const char *addr, const char *fmt)
969 int i;
971 for (i = 0; i < 8; i++) {
972 p = hex_byte_pack(p, *addr++);
973 p = hex_byte_pack(p, *addr++);
974 if (fmt[0] == 'I' && i != 7)
975 *p++ = ':';
977 *p = '\0';
979 return p;
982 static noinline_for_stack
983 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
984 struct printf_spec spec, const char *fmt)
986 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
988 if (fmt[0] == 'I' && fmt[2] == 'c')
989 ip6_compressed_string(ip6_addr, addr);
990 else
991 ip6_string(ip6_addr, addr, fmt);
993 return string(buf, end, ip6_addr, spec);
996 static noinline_for_stack
997 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
998 struct printf_spec spec, const char *fmt)
1000 char ip4_addr[sizeof("255.255.255.255")];
1002 ip4_string(ip4_addr, addr, fmt);
1004 return string(buf, end, ip4_addr, spec);
1007 static noinline_for_stack
1008 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1009 struct printf_spec spec, const char *fmt)
1011 bool have_p = false, have_s = false, have_f = false, have_c = false;
1012 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1013 sizeof(":12345") + sizeof("/123456789") +
1014 sizeof("%1234567890")];
1015 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1016 const u8 *addr = (const u8 *) &sa->sin6_addr;
1017 char fmt6[2] = { fmt[0], '6' };
1018 u8 off = 0;
1020 fmt++;
1021 while (isalpha(*++fmt)) {
1022 switch (*fmt) {
1023 case 'p':
1024 have_p = true;
1025 break;
1026 case 'f':
1027 have_f = true;
1028 break;
1029 case 's':
1030 have_s = true;
1031 break;
1032 case 'c':
1033 have_c = true;
1034 break;
1038 if (have_p || have_s || have_f) {
1039 *p = '[';
1040 off = 1;
1043 if (fmt6[0] == 'I' && have_c)
1044 p = ip6_compressed_string(ip6_addr + off, addr);
1045 else
1046 p = ip6_string(ip6_addr + off, addr, fmt6);
1048 if (have_p || have_s || have_f)
1049 *p++ = ']';
1051 if (have_p) {
1052 *p++ = ':';
1053 p = number(p, pend, ntohs(sa->sin6_port), spec);
1055 if (have_f) {
1056 *p++ = '/';
1057 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1058 IPV6_FLOWINFO_MASK), spec);
1060 if (have_s) {
1061 *p++ = '%';
1062 p = number(p, pend, sa->sin6_scope_id, spec);
1064 *p = '\0';
1066 return string(buf, end, ip6_addr, spec);
1069 static noinline_for_stack
1070 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1071 struct printf_spec spec, const char *fmt)
1073 bool have_p = false;
1074 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1075 char *pend = ip4_addr + sizeof(ip4_addr);
1076 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1077 char fmt4[3] = { fmt[0], '4', 0 };
1079 fmt++;
1080 while (isalpha(*++fmt)) {
1081 switch (*fmt) {
1082 case 'p':
1083 have_p = true;
1084 break;
1085 case 'h':
1086 case 'l':
1087 case 'n':
1088 case 'b':
1089 fmt4[2] = *fmt;
1090 break;
1094 p = ip4_string(ip4_addr, addr, fmt4);
1095 if (have_p) {
1096 *p++ = ':';
1097 p = number(p, pend, ntohs(sa->sin_port), spec);
1099 *p = '\0';
1101 return string(buf, end, ip4_addr, spec);
1104 static noinline_for_stack
1105 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1106 const char *fmt)
1108 bool found = true;
1109 int count = 1;
1110 unsigned int flags = 0;
1111 int len;
1113 if (spec.field_width == 0)
1114 return buf; /* nothing to print */
1116 if (ZERO_OR_NULL_PTR(addr))
1117 return string(buf, end, NULL, spec); /* NULL pointer */
1120 do {
1121 switch (fmt[count++]) {
1122 case 'a':
1123 flags |= ESCAPE_ANY;
1124 break;
1125 case 'c':
1126 flags |= ESCAPE_SPECIAL;
1127 break;
1128 case 'h':
1129 flags |= ESCAPE_HEX;
1130 break;
1131 case 'n':
1132 flags |= ESCAPE_NULL;
1133 break;
1134 case 'o':
1135 flags |= ESCAPE_OCTAL;
1136 break;
1137 case 'p':
1138 flags |= ESCAPE_NP;
1139 break;
1140 case 's':
1141 flags |= ESCAPE_SPACE;
1142 break;
1143 default:
1144 found = false;
1145 break;
1147 } while (found);
1149 if (!flags)
1150 flags = ESCAPE_ANY_NP;
1152 len = spec.field_width < 0 ? 1 : spec.field_width;
1154 /* Ignore the error. We print as many characters as we can */
1155 string_escape_mem(addr, len, &buf, end - buf, flags, NULL);
1157 return buf;
1160 static noinline_for_stack
1161 char *uuid_string(char *buf, char *end, const u8 *addr,
1162 struct printf_spec spec, const char *fmt)
1164 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1165 char *p = uuid;
1166 int i;
1167 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1168 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1169 const u8 *index = be;
1170 bool uc = false;
1172 switch (*(++fmt)) {
1173 case 'L':
1174 uc = true; /* fall-through */
1175 case 'l':
1176 index = le;
1177 break;
1178 case 'B':
1179 uc = true;
1180 break;
1183 for (i = 0; i < 16; i++) {
1184 p = hex_byte_pack(p, addr[index[i]]);
1185 switch (i) {
1186 case 3:
1187 case 5:
1188 case 7:
1189 case 9:
1190 *p++ = '-';
1191 break;
1195 *p = 0;
1197 if (uc) {
1198 p = uuid;
1199 do {
1200 *p = toupper(*p);
1201 } while (*(++p));
1204 return string(buf, end, uuid, spec);
1207 static
1208 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1209 struct printf_spec spec)
1211 spec.flags |= SPECIAL | SMALL | ZEROPAD;
1212 if (spec.field_width == -1)
1213 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1214 spec.base = 16;
1216 return number(buf, end, *(const netdev_features_t *)addr, spec);
1219 static noinline_for_stack
1220 char *address_val(char *buf, char *end, const void *addr,
1221 struct printf_spec spec, const char *fmt)
1223 unsigned long long num;
1225 spec.flags |= SPECIAL | SMALL | ZEROPAD;
1226 spec.base = 16;
1228 switch (fmt[1]) {
1229 case 'd':
1230 num = *(const dma_addr_t *)addr;
1231 spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1232 break;
1233 case 'p':
1234 default:
1235 num = *(const phys_addr_t *)addr;
1236 spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1237 break;
1240 return number(buf, end, num, spec);
1243 int kptr_restrict __read_mostly;
1246 * Show a '%p' thing. A kernel extension is that the '%p' is followed
1247 * by an extra set of alphanumeric characters that are extended format
1248 * specifiers.
1250 * Right now we handle:
1252 * - 'F' For symbolic function descriptor pointers with offset
1253 * - 'f' For simple symbolic function names without offset
1254 * - 'S' For symbolic direct pointers with offset
1255 * - 's' For symbolic direct pointers without offset
1256 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1257 * - 'B' For backtraced symbolic direct pointers with offset
1258 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1259 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1260 * - 'M' For a 6-byte MAC address, it prints the address in the
1261 * usual colon-separated hex notation
1262 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1263 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1264 * with a dash-separated hex notation
1265 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1266 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1267 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1268 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
1269 * [S][pfs]
1270 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1271 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1272 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1273 * IPv6 omits the colons (01020304...0f)
1274 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1275 * [S][pfs]
1276 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1277 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1278 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1279 * - 'I[6S]c' for IPv6 addresses printed as specified by
1280 * http://tools.ietf.org/html/rfc5952
1281 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1282 * of the following flags (see string_escape_mem() for the
1283 * details):
1284 * a - ESCAPE_ANY
1285 * c - ESCAPE_SPECIAL
1286 * h - ESCAPE_HEX
1287 * n - ESCAPE_NULL
1288 * o - ESCAPE_OCTAL
1289 * p - ESCAPE_NP
1290 * s - ESCAPE_SPACE
1291 * By default ESCAPE_ANY_NP is used.
1292 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1293 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1294 * Options for %pU are:
1295 * b big endian lower case hex (default)
1296 * B big endian UPPER case hex
1297 * l little endian lower case hex
1298 * L little endian UPPER case hex
1299 * big endian output byte order is:
1300 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1301 * little endian output byte order is:
1302 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1303 * - 'V' For a struct va_format which contains a format string * and va_list *,
1304 * call vsnprintf(->format, *->va_list).
1305 * Implements a "recursive vsnprintf".
1306 * Do not use this feature without some mechanism to verify the
1307 * correctness of the format string and va_list arguments.
1308 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1309 * - 'NF' For a netdev_features_t
1310 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1311 * a certain separator (' ' by default):
1312 * C colon
1313 * D dash
1314 * N no separator
1315 * The maximum supported length is 64 bytes of the input. Consider
1316 * to use print_hex_dump() for the larger input.
1317 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1318 * (default assumed to be phys_addr_t, passed by reference)
1319 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1320 * - 'D[234]' Same as 'd' but for a struct file
1322 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1323 * function pointers are really function descriptors, which contain a
1324 * pointer to the real address.
1326 static noinline_for_stack
1327 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1328 struct printf_spec spec)
1330 int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1332 if (!ptr && *fmt != 'K') {
1334 * Print (null) with the same width as a pointer so it makes
1335 * tabular output look nice.
1337 if (spec.field_width == -1)
1338 spec.field_width = default_width;
1339 return string(buf, end, "(null)", spec);
1342 switch (*fmt) {
1343 case 'F':
1344 case 'f':
1345 ptr = dereference_function_descriptor(ptr);
1346 /* Fallthrough */
1347 case 'S':
1348 case 's':
1349 case 'B':
1350 return symbol_string(buf, end, ptr, spec, fmt);
1351 case 'R':
1352 case 'r':
1353 return resource_string(buf, end, ptr, spec, fmt);
1354 case 'h':
1355 return hex_string(buf, end, ptr, spec, fmt);
1356 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1357 case 'm': /* Contiguous: 000102030405 */
1358 /* [mM]F (FDDI) */
1359 /* [mM]R (Reverse order; Bluetooth) */
1360 return mac_address_string(buf, end, ptr, spec, fmt);
1361 case 'I': /* Formatted IP supported
1362 * 4: 1.2.3.4
1363 * 6: 0001:0203:...:0708
1364 * 6c: 1::708 or 1::1.2.3.4
1366 case 'i': /* Contiguous:
1367 * 4: 001.002.003.004
1368 * 6: 000102...0f
1370 switch (fmt[1]) {
1371 case '6':
1372 return ip6_addr_string(buf, end, ptr, spec, fmt);
1373 case '4':
1374 return ip4_addr_string(buf, end, ptr, spec, fmt);
1375 case 'S': {
1376 const union {
1377 struct sockaddr raw;
1378 struct sockaddr_in v4;
1379 struct sockaddr_in6 v6;
1380 } *sa = ptr;
1382 switch (sa->raw.sa_family) {
1383 case AF_INET:
1384 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1385 case AF_INET6:
1386 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1387 default:
1388 return string(buf, end, "(invalid address)", spec);
1391 break;
1392 case 'E':
1393 return escaped_string(buf, end, ptr, spec, fmt);
1394 case 'U':
1395 return uuid_string(buf, end, ptr, spec, fmt);
1396 case 'V':
1398 va_list va;
1400 va_copy(va, *((struct va_format *)ptr)->va);
1401 buf += vsnprintf(buf, end > buf ? end - buf : 0,
1402 ((struct va_format *)ptr)->fmt, va);
1403 va_end(va);
1404 return buf;
1406 case 'K':
1408 * %pK cannot be used in IRQ context because its test
1409 * for CAP_SYSLOG would be meaningless.
1411 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1412 in_nmi())) {
1413 if (spec.field_width == -1)
1414 spec.field_width = default_width;
1415 return string(buf, end, "pK-error", spec);
1418 switch (kptr_restrict) {
1419 case 0:
1420 /* Always print %pK values */
1421 break;
1422 case 1: {
1424 * Only print the real pointer value if the current
1425 * process has CAP_SYSLOG and is running with the
1426 * same credentials it started with. This is because
1427 * access to files is checked at open() time, but %pK
1428 * checks permission at read() time. We don't want to
1429 * leak pointer values if a binary opens a file using
1430 * %pK and then elevates privileges before reading it.
1432 const struct cred *cred = current_cred();
1434 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1435 !uid_eq(cred->euid, cred->uid) ||
1436 !gid_eq(cred->egid, cred->gid))
1437 ptr = NULL;
1438 break;
1440 case 2:
1441 default:
1442 /* Always print 0's for %pK */
1443 ptr = NULL;
1444 break;
1446 break;
1448 case 'N':
1449 switch (fmt[1]) {
1450 case 'F':
1451 return netdev_feature_string(buf, end, ptr, spec);
1453 break;
1454 case 'a':
1455 return address_val(buf, end, ptr, spec, fmt);
1456 case 'd':
1457 return dentry_name(buf, end, ptr, spec, fmt);
1458 case 'D':
1459 return dentry_name(buf, end,
1460 ((const struct file *)ptr)->f_path.dentry,
1461 spec, fmt);
1463 spec.flags |= SMALL;
1464 if (spec.field_width == -1) {
1465 spec.field_width = default_width;
1466 spec.flags |= ZEROPAD;
1468 spec.base = 16;
1470 return number(buf, end, (unsigned long) ptr, spec);
1474 * Helper function to decode printf style format.
1475 * Each call decode a token from the format and return the
1476 * number of characters read (or likely the delta where it wants
1477 * to go on the next call).
1478 * The decoded token is returned through the parameters
1480 * 'h', 'l', or 'L' for integer fields
1481 * 'z' support added 23/7/1999 S.H.
1482 * 'z' changed to 'Z' --davidm 1/25/99
1483 * 't' added for ptrdiff_t
1485 * @fmt: the format string
1486 * @type of the token returned
1487 * @flags: various flags such as +, -, # tokens..
1488 * @field_width: overwritten width
1489 * @base: base of the number (octal, hex, ...)
1490 * @precision: precision of a number
1491 * @qualifier: qualifier of a number (long, size_t, ...)
1493 static noinline_for_stack
1494 int format_decode(const char *fmt, struct printf_spec *spec)
1496 const char *start = fmt;
1498 /* we finished early by reading the field width */
1499 if (spec->type == FORMAT_TYPE_WIDTH) {
1500 if (spec->field_width < 0) {
1501 spec->field_width = -spec->field_width;
1502 spec->flags |= LEFT;
1504 spec->type = FORMAT_TYPE_NONE;
1505 goto precision;
1508 /* we finished early by reading the precision */
1509 if (spec->type == FORMAT_TYPE_PRECISION) {
1510 if (spec->precision < 0)
1511 spec->precision = 0;
1513 spec->type = FORMAT_TYPE_NONE;
1514 goto qualifier;
1517 /* By default */
1518 spec->type = FORMAT_TYPE_NONE;
1520 for (; *fmt ; ++fmt) {
1521 if (*fmt == '%')
1522 break;
1525 /* Return the current non-format string */
1526 if (fmt != start || !*fmt)
1527 return fmt - start;
1529 /* Process flags */
1530 spec->flags = 0;
1532 while (1) { /* this also skips first '%' */
1533 bool found = true;
1535 ++fmt;
1537 switch (*fmt) {
1538 case '-': spec->flags |= LEFT; break;
1539 case '+': spec->flags |= PLUS; break;
1540 case ' ': spec->flags |= SPACE; break;
1541 case '#': spec->flags |= SPECIAL; break;
1542 case '0': spec->flags |= ZEROPAD; break;
1543 default: found = false;
1546 if (!found)
1547 break;
1550 /* get field width */
1551 spec->field_width = -1;
1553 if (isdigit(*fmt))
1554 spec->field_width = skip_atoi(&fmt);
1555 else if (*fmt == '*') {
1556 /* it's the next argument */
1557 spec->type = FORMAT_TYPE_WIDTH;
1558 return ++fmt - start;
1561 precision:
1562 /* get the precision */
1563 spec->precision = -1;
1564 if (*fmt == '.') {
1565 ++fmt;
1566 if (isdigit(*fmt)) {
1567 spec->precision = skip_atoi(&fmt);
1568 if (spec->precision < 0)
1569 spec->precision = 0;
1570 } else if (*fmt == '*') {
1571 /* it's the next argument */
1572 spec->type = FORMAT_TYPE_PRECISION;
1573 return ++fmt - start;
1577 qualifier:
1578 /* get the conversion qualifier */
1579 spec->qualifier = -1;
1580 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1581 _tolower(*fmt) == 'z' || *fmt == 't') {
1582 spec->qualifier = *fmt++;
1583 if (unlikely(spec->qualifier == *fmt)) {
1584 if (spec->qualifier == 'l') {
1585 spec->qualifier = 'L';
1586 ++fmt;
1587 } else if (spec->qualifier == 'h') {
1588 spec->qualifier = 'H';
1589 ++fmt;
1594 /* default base */
1595 spec->base = 10;
1596 switch (*fmt) {
1597 case 'c':
1598 spec->type = FORMAT_TYPE_CHAR;
1599 return ++fmt - start;
1601 case 's':
1602 spec->type = FORMAT_TYPE_STR;
1603 return ++fmt - start;
1605 case 'p':
1606 spec->type = FORMAT_TYPE_PTR;
1607 return fmt - start;
1608 /* skip alnum */
1610 case '%':
1611 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1612 return ++fmt - start;
1614 /* integer number formats - set up the flags and "break" */
1615 case 'o':
1616 spec->base = 8;
1617 break;
1619 case 'x':
1620 spec->flags |= SMALL;
1622 case 'X':
1623 spec->base = 16;
1624 break;
1626 case 'd':
1627 case 'i':
1628 spec->flags |= SIGN;
1629 case 'u':
1630 break;
1632 case 'n':
1634 * Since %n poses a greater security risk than utility, treat
1635 * it as an invalid format specifier. Warn about its use so
1636 * that new instances don't get added.
1638 WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1639 /* Fall-through */
1641 default:
1642 spec->type = FORMAT_TYPE_INVALID;
1643 return fmt - start;
1646 if (spec->qualifier == 'L')
1647 spec->type = FORMAT_TYPE_LONG_LONG;
1648 else if (spec->qualifier == 'l') {
1649 if (spec->flags & SIGN)
1650 spec->type = FORMAT_TYPE_LONG;
1651 else
1652 spec->type = FORMAT_TYPE_ULONG;
1653 } else if (_tolower(spec->qualifier) == 'z') {
1654 spec->type = FORMAT_TYPE_SIZE_T;
1655 } else if (spec->qualifier == 't') {
1656 spec->type = FORMAT_TYPE_PTRDIFF;
1657 } else if (spec->qualifier == 'H') {
1658 if (spec->flags & SIGN)
1659 spec->type = FORMAT_TYPE_BYTE;
1660 else
1661 spec->type = FORMAT_TYPE_UBYTE;
1662 } else if (spec->qualifier == 'h') {
1663 if (spec->flags & SIGN)
1664 spec->type = FORMAT_TYPE_SHORT;
1665 else
1666 spec->type = FORMAT_TYPE_USHORT;
1667 } else {
1668 if (spec->flags & SIGN)
1669 spec->type = FORMAT_TYPE_INT;
1670 else
1671 spec->type = FORMAT_TYPE_UINT;
1674 return ++fmt - start;
1678 * vsnprintf - Format a string and place it in a buffer
1679 * @buf: The buffer to place the result into
1680 * @size: The size of the buffer, including the trailing null space
1681 * @fmt: The format string to use
1682 * @args: Arguments for the format string
1684 * This function follows C99 vsnprintf, but has some extensions:
1685 * %pS output the name of a text symbol with offset
1686 * %ps output the name of a text symbol without offset
1687 * %pF output the name of a function pointer with its offset
1688 * %pf output the name of a function pointer without its offset
1689 * %pB output the name of a backtrace symbol with its offset
1690 * %pR output the address range in a struct resource with decoded flags
1691 * %pr output the address range in a struct resource with raw flags
1692 * %pM output a 6-byte MAC address with colons
1693 * %pMR output a 6-byte MAC address with colons in reversed order
1694 * %pMF output a 6-byte MAC address with dashes
1695 * %pm output a 6-byte MAC address without colons
1696 * %pmR output a 6-byte MAC address without colons in reversed order
1697 * %pI4 print an IPv4 address without leading zeros
1698 * %pi4 print an IPv4 address with leading zeros
1699 * %pI6 print an IPv6 address with colons
1700 * %pi6 print an IPv6 address without colons
1701 * %pI6c print an IPv6 address as specified by RFC 5952
1702 * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1703 * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1704 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1705 * case.
1706 * %*pE[achnops] print an escaped buffer
1707 * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1708 * bytes of the input)
1709 * %n is ignored
1711 * ** Please update Documentation/printk-formats.txt when making changes **
1713 * The return value is the number of characters which would
1714 * be generated for the given input, excluding the trailing
1715 * '\0', as per ISO C99. If you want to have the exact
1716 * number of characters written into @buf as return value
1717 * (not including the trailing '\0'), use vscnprintf(). If the
1718 * return is greater than or equal to @size, the resulting
1719 * string is truncated.
1721 * If you're not already dealing with a va_list consider using snprintf().
1723 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1725 unsigned long long num;
1726 char *str, *end;
1727 struct printf_spec spec = {0};
1729 /* Reject out-of-range values early. Large positive sizes are
1730 used for unknown buffer sizes. */
1731 if (WARN_ON_ONCE((int) size < 0))
1732 return 0;
1734 str = buf;
1735 end = buf + size;
1737 /* Make sure end is always >= buf */
1738 if (end < buf) {
1739 end = ((void *)-1);
1740 size = end - buf;
1743 while (*fmt) {
1744 const char *old_fmt = fmt;
1745 int read = format_decode(fmt, &spec);
1747 fmt += read;
1749 switch (spec.type) {
1750 case FORMAT_TYPE_NONE: {
1751 int copy = read;
1752 if (str < end) {
1753 if (copy > end - str)
1754 copy = end - str;
1755 memcpy(str, old_fmt, copy);
1757 str += read;
1758 break;
1761 case FORMAT_TYPE_WIDTH:
1762 spec.field_width = va_arg(args, int);
1763 break;
1765 case FORMAT_TYPE_PRECISION:
1766 spec.precision = va_arg(args, int);
1767 break;
1769 case FORMAT_TYPE_CHAR: {
1770 char c;
1772 if (!(spec.flags & LEFT)) {
1773 while (--spec.field_width > 0) {
1774 if (str < end)
1775 *str = ' ';
1776 ++str;
1780 c = (unsigned char) va_arg(args, int);
1781 if (str < end)
1782 *str = c;
1783 ++str;
1784 while (--spec.field_width > 0) {
1785 if (str < end)
1786 *str = ' ';
1787 ++str;
1789 break;
1792 case FORMAT_TYPE_STR:
1793 str = string(str, end, va_arg(args, char *), spec);
1794 break;
1796 case FORMAT_TYPE_PTR:
1797 str = pointer(fmt+1, str, end, va_arg(args, void *),
1798 spec);
1799 while (isalnum(*fmt))
1800 fmt++;
1801 break;
1803 case FORMAT_TYPE_PERCENT_CHAR:
1804 if (str < end)
1805 *str = '%';
1806 ++str;
1807 break;
1809 case FORMAT_TYPE_INVALID:
1810 if (str < end)
1811 *str = '%';
1812 ++str;
1813 break;
1815 default:
1816 switch (spec.type) {
1817 case FORMAT_TYPE_LONG_LONG:
1818 num = va_arg(args, long long);
1819 break;
1820 case FORMAT_TYPE_ULONG:
1821 num = va_arg(args, unsigned long);
1822 break;
1823 case FORMAT_TYPE_LONG:
1824 num = va_arg(args, long);
1825 break;
1826 case FORMAT_TYPE_SIZE_T:
1827 if (spec.flags & SIGN)
1828 num = va_arg(args, ssize_t);
1829 else
1830 num = va_arg(args, size_t);
1831 break;
1832 case FORMAT_TYPE_PTRDIFF:
1833 num = va_arg(args, ptrdiff_t);
1834 break;
1835 case FORMAT_TYPE_UBYTE:
1836 num = (unsigned char) va_arg(args, int);
1837 break;
1838 case FORMAT_TYPE_BYTE:
1839 num = (signed char) va_arg(args, int);
1840 break;
1841 case FORMAT_TYPE_USHORT:
1842 num = (unsigned short) va_arg(args, int);
1843 break;
1844 case FORMAT_TYPE_SHORT:
1845 num = (short) va_arg(args, int);
1846 break;
1847 case FORMAT_TYPE_INT:
1848 num = (int) va_arg(args, int);
1849 break;
1850 default:
1851 num = va_arg(args, unsigned int);
1854 str = number(str, end, num, spec);
1858 if (size > 0) {
1859 if (str < end)
1860 *str = '\0';
1861 else
1862 end[-1] = '\0';
1865 /* the trailing null byte doesn't count towards the total */
1866 return str-buf;
1869 EXPORT_SYMBOL(vsnprintf);
1872 * vscnprintf - Format a string and place it in a buffer
1873 * @buf: The buffer to place the result into
1874 * @size: The size of the buffer, including the trailing null space
1875 * @fmt: The format string to use
1876 * @args: Arguments for the format string
1878 * The return value is the number of characters which have been written into
1879 * the @buf not including the trailing '\0'. If @size is == 0 the function
1880 * returns 0.
1882 * If you're not already dealing with a va_list consider using scnprintf().
1884 * See the vsnprintf() documentation for format string extensions over C99.
1886 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1888 int i;
1890 i = vsnprintf(buf, size, fmt, args);
1892 if (likely(i < size))
1893 return i;
1894 if (size != 0)
1895 return size - 1;
1896 return 0;
1898 EXPORT_SYMBOL(vscnprintf);
1901 * snprintf - Format a string and place it in a buffer
1902 * @buf: The buffer to place the result into
1903 * @size: The size of the buffer, including the trailing null space
1904 * @fmt: The format string to use
1905 * @...: Arguments for the format string
1907 * The return value is the number of characters which would be
1908 * generated for the given input, excluding the trailing null,
1909 * as per ISO C99. If the return is greater than or equal to
1910 * @size, the resulting string is truncated.
1912 * See the vsnprintf() documentation for format string extensions over C99.
1914 int snprintf(char *buf, size_t size, const char *fmt, ...)
1916 va_list args;
1917 int i;
1919 va_start(args, fmt);
1920 i = vsnprintf(buf, size, fmt, args);
1921 va_end(args);
1923 return i;
1925 EXPORT_SYMBOL(snprintf);
1928 * scnprintf - Format a string and place it in a buffer
1929 * @buf: The buffer to place the result into
1930 * @size: The size of the buffer, including the trailing null space
1931 * @fmt: The format string to use
1932 * @...: Arguments for the format string
1934 * The return value is the number of characters written into @buf not including
1935 * the trailing '\0'. If @size is == 0 the function returns 0.
1938 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1940 va_list args;
1941 int i;
1943 va_start(args, fmt);
1944 i = vscnprintf(buf, size, fmt, args);
1945 va_end(args);
1947 return i;
1949 EXPORT_SYMBOL(scnprintf);
1952 * vsprintf - Format a string and place it in a buffer
1953 * @buf: The buffer to place the result into
1954 * @fmt: The format string to use
1955 * @args: Arguments for the format string
1957 * The function returns the number of characters written
1958 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1959 * buffer overflows.
1961 * If you're not already dealing with a va_list consider using sprintf().
1963 * See the vsnprintf() documentation for format string extensions over C99.
1965 int vsprintf(char *buf, const char *fmt, va_list args)
1967 return vsnprintf(buf, INT_MAX, fmt, args);
1969 EXPORT_SYMBOL(vsprintf);
1972 * sprintf - Format a string and place it in a buffer
1973 * @buf: The buffer to place the result into
1974 * @fmt: The format string to use
1975 * @...: Arguments for the format string
1977 * The function returns the number of characters written
1978 * into @buf. Use snprintf() or scnprintf() in order to avoid
1979 * buffer overflows.
1981 * See the vsnprintf() documentation for format string extensions over C99.
1983 int sprintf(char *buf, const char *fmt, ...)
1985 va_list args;
1986 int i;
1988 va_start(args, fmt);
1989 i = vsnprintf(buf, INT_MAX, fmt, args);
1990 va_end(args);
1992 return i;
1994 EXPORT_SYMBOL(sprintf);
1996 #ifdef CONFIG_BINARY_PRINTF
1998 * bprintf service:
1999 * vbin_printf() - VA arguments to binary data
2000 * bstr_printf() - Binary data to text string
2004 * vbin_printf - Parse a format string and place args' binary value in a buffer
2005 * @bin_buf: The buffer to place args' binary value
2006 * @size: The size of the buffer(by words(32bits), not characters)
2007 * @fmt: The format string to use
2008 * @args: Arguments for the format string
2010 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2011 * is skipped.
2013 * The return value is the number of words(32bits) which would be generated for
2014 * the given input.
2016 * NOTE:
2017 * If the return value is greater than @size, the resulting bin_buf is NOT
2018 * valid for bstr_printf().
2020 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2022 struct printf_spec spec = {0};
2023 char *str, *end;
2025 str = (char *)bin_buf;
2026 end = (char *)(bin_buf + size);
2028 #define save_arg(type) \
2029 do { \
2030 if (sizeof(type) == 8) { \
2031 unsigned long long value; \
2032 str = PTR_ALIGN(str, sizeof(u32)); \
2033 value = va_arg(args, unsigned long long); \
2034 if (str + sizeof(type) <= end) { \
2035 *(u32 *)str = *(u32 *)&value; \
2036 *(u32 *)(str + 4) = *((u32 *)&value + 1); \
2038 } else { \
2039 unsigned long value; \
2040 str = PTR_ALIGN(str, sizeof(type)); \
2041 value = va_arg(args, int); \
2042 if (str + sizeof(type) <= end) \
2043 *(typeof(type) *)str = (type)value; \
2045 str += sizeof(type); \
2046 } while (0)
2048 while (*fmt) {
2049 int read = format_decode(fmt, &spec);
2051 fmt += read;
2053 switch (spec.type) {
2054 case FORMAT_TYPE_NONE:
2055 case FORMAT_TYPE_INVALID:
2056 case FORMAT_TYPE_PERCENT_CHAR:
2057 break;
2059 case FORMAT_TYPE_WIDTH:
2060 case FORMAT_TYPE_PRECISION:
2061 save_arg(int);
2062 break;
2064 case FORMAT_TYPE_CHAR:
2065 save_arg(char);
2066 break;
2068 case FORMAT_TYPE_STR: {
2069 const char *save_str = va_arg(args, char *);
2070 size_t len;
2072 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2073 || (unsigned long)save_str < PAGE_SIZE)
2074 save_str = "(null)";
2075 len = strlen(save_str) + 1;
2076 if (str + len < end)
2077 memcpy(str, save_str, len);
2078 str += len;
2079 break;
2082 case FORMAT_TYPE_PTR:
2083 save_arg(void *);
2084 /* skip all alphanumeric pointer suffixes */
2085 while (isalnum(*fmt))
2086 fmt++;
2087 break;
2089 default:
2090 switch (spec.type) {
2092 case FORMAT_TYPE_LONG_LONG:
2093 save_arg(long long);
2094 break;
2095 case FORMAT_TYPE_ULONG:
2096 case FORMAT_TYPE_LONG:
2097 save_arg(unsigned long);
2098 break;
2099 case FORMAT_TYPE_SIZE_T:
2100 save_arg(size_t);
2101 break;
2102 case FORMAT_TYPE_PTRDIFF:
2103 save_arg(ptrdiff_t);
2104 break;
2105 case FORMAT_TYPE_UBYTE:
2106 case FORMAT_TYPE_BYTE:
2107 save_arg(char);
2108 break;
2109 case FORMAT_TYPE_USHORT:
2110 case FORMAT_TYPE_SHORT:
2111 save_arg(short);
2112 break;
2113 default:
2114 save_arg(int);
2119 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2120 #undef save_arg
2122 EXPORT_SYMBOL_GPL(vbin_printf);
2125 * bstr_printf - Format a string from binary arguments and place it in a buffer
2126 * @buf: The buffer to place the result into
2127 * @size: The size of the buffer, including the trailing null space
2128 * @fmt: The format string to use
2129 * @bin_buf: Binary arguments for the format string
2131 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2132 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2133 * a binary buffer that generated by vbin_printf.
2135 * The format follows C99 vsnprintf, but has some extensions:
2136 * see vsnprintf comment for details.
2138 * The return value is the number of characters which would
2139 * be generated for the given input, excluding the trailing
2140 * '\0', as per ISO C99. If you want to have the exact
2141 * number of characters written into @buf as return value
2142 * (not including the trailing '\0'), use vscnprintf(). If the
2143 * return is greater than or equal to @size, the resulting
2144 * string is truncated.
2146 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2148 struct printf_spec spec = {0};
2149 char *str, *end;
2150 const char *args = (const char *)bin_buf;
2152 if (WARN_ON_ONCE((int) size < 0))
2153 return 0;
2155 str = buf;
2156 end = buf + size;
2158 #define get_arg(type) \
2159 ({ \
2160 typeof(type) value; \
2161 if (sizeof(type) == 8) { \
2162 args = PTR_ALIGN(args, sizeof(u32)); \
2163 *(u32 *)&value = *(u32 *)args; \
2164 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
2165 } else { \
2166 args = PTR_ALIGN(args, sizeof(type)); \
2167 value = *(typeof(type) *)args; \
2169 args += sizeof(type); \
2170 value; \
2173 /* Make sure end is always >= buf */
2174 if (end < buf) {
2175 end = ((void *)-1);
2176 size = end - buf;
2179 while (*fmt) {
2180 const char *old_fmt = fmt;
2181 int read = format_decode(fmt, &spec);
2183 fmt += read;
2185 switch (spec.type) {
2186 case FORMAT_TYPE_NONE: {
2187 int copy = read;
2188 if (str < end) {
2189 if (copy > end - str)
2190 copy = end - str;
2191 memcpy(str, old_fmt, copy);
2193 str += read;
2194 break;
2197 case FORMAT_TYPE_WIDTH:
2198 spec.field_width = get_arg(int);
2199 break;
2201 case FORMAT_TYPE_PRECISION:
2202 spec.precision = get_arg(int);
2203 break;
2205 case FORMAT_TYPE_CHAR: {
2206 char c;
2208 if (!(spec.flags & LEFT)) {
2209 while (--spec.field_width > 0) {
2210 if (str < end)
2211 *str = ' ';
2212 ++str;
2215 c = (unsigned char) get_arg(char);
2216 if (str < end)
2217 *str = c;
2218 ++str;
2219 while (--spec.field_width > 0) {
2220 if (str < end)
2221 *str = ' ';
2222 ++str;
2224 break;
2227 case FORMAT_TYPE_STR: {
2228 const char *str_arg = args;
2229 args += strlen(str_arg) + 1;
2230 str = string(str, end, (char *)str_arg, spec);
2231 break;
2234 case FORMAT_TYPE_PTR:
2235 str = pointer(fmt+1, str, end, get_arg(void *), spec);
2236 while (isalnum(*fmt))
2237 fmt++;
2238 break;
2240 case FORMAT_TYPE_PERCENT_CHAR:
2241 case FORMAT_TYPE_INVALID:
2242 if (str < end)
2243 *str = '%';
2244 ++str;
2245 break;
2247 default: {
2248 unsigned long long num;
2250 switch (spec.type) {
2252 case FORMAT_TYPE_LONG_LONG:
2253 num = get_arg(long long);
2254 break;
2255 case FORMAT_TYPE_ULONG:
2256 case FORMAT_TYPE_LONG:
2257 num = get_arg(unsigned long);
2258 break;
2259 case FORMAT_TYPE_SIZE_T:
2260 num = get_arg(size_t);
2261 break;
2262 case FORMAT_TYPE_PTRDIFF:
2263 num = get_arg(ptrdiff_t);
2264 break;
2265 case FORMAT_TYPE_UBYTE:
2266 num = get_arg(unsigned char);
2267 break;
2268 case FORMAT_TYPE_BYTE:
2269 num = get_arg(signed char);
2270 break;
2271 case FORMAT_TYPE_USHORT:
2272 num = get_arg(unsigned short);
2273 break;
2274 case FORMAT_TYPE_SHORT:
2275 num = get_arg(short);
2276 break;
2277 case FORMAT_TYPE_UINT:
2278 num = get_arg(unsigned int);
2279 break;
2280 default:
2281 num = get_arg(int);
2284 str = number(str, end, num, spec);
2285 } /* default: */
2286 } /* switch(spec.type) */
2287 } /* while(*fmt) */
2289 if (size > 0) {
2290 if (str < end)
2291 *str = '\0';
2292 else
2293 end[-1] = '\0';
2296 #undef get_arg
2298 /* the trailing null byte doesn't count towards the total */
2299 return str - buf;
2301 EXPORT_SYMBOL_GPL(bstr_printf);
2304 * bprintf - Parse a format string and place args' binary value in a buffer
2305 * @bin_buf: The buffer to place args' binary value
2306 * @size: The size of the buffer(by words(32bits), not characters)
2307 * @fmt: The format string to use
2308 * @...: Arguments for the format string
2310 * The function returns the number of words(u32) written
2311 * into @bin_buf.
2313 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2315 va_list args;
2316 int ret;
2318 va_start(args, fmt);
2319 ret = vbin_printf(bin_buf, size, fmt, args);
2320 va_end(args);
2322 return ret;
2324 EXPORT_SYMBOL_GPL(bprintf);
2326 #endif /* CONFIG_BINARY_PRINTF */
2329 * vsscanf - Unformat a buffer into a list of arguments
2330 * @buf: input buffer
2331 * @fmt: format of buffer
2332 * @args: arguments
2334 int vsscanf(const char *buf, const char *fmt, va_list args)
2336 const char *str = buf;
2337 char *next;
2338 char digit;
2339 int num = 0;
2340 u8 qualifier;
2341 unsigned int base;
2342 union {
2343 long long s;
2344 unsigned long long u;
2345 } val;
2346 s16 field_width;
2347 bool is_sign;
2349 while (*fmt) {
2350 /* skip any white space in format */
2351 /* white space in format matchs any amount of
2352 * white space, including none, in the input.
2354 if (isspace(*fmt)) {
2355 fmt = skip_spaces(++fmt);
2356 str = skip_spaces(str);
2359 /* anything that is not a conversion must match exactly */
2360 if (*fmt != '%' && *fmt) {
2361 if (*fmt++ != *str++)
2362 break;
2363 continue;
2366 if (!*fmt)
2367 break;
2368 ++fmt;
2370 /* skip this conversion.
2371 * advance both strings to next white space
2373 if (*fmt == '*') {
2374 if (!*str)
2375 break;
2376 while (!isspace(*fmt) && *fmt != '%' && *fmt)
2377 fmt++;
2378 while (!isspace(*str) && *str)
2379 str++;
2380 continue;
2383 /* get field width */
2384 field_width = -1;
2385 if (isdigit(*fmt)) {
2386 field_width = skip_atoi(&fmt);
2387 if (field_width <= 0)
2388 break;
2391 /* get conversion qualifier */
2392 qualifier = -1;
2393 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2394 _tolower(*fmt) == 'z') {
2395 qualifier = *fmt++;
2396 if (unlikely(qualifier == *fmt)) {
2397 if (qualifier == 'h') {
2398 qualifier = 'H';
2399 fmt++;
2400 } else if (qualifier == 'l') {
2401 qualifier = 'L';
2402 fmt++;
2407 if (!*fmt)
2408 break;
2410 if (*fmt == 'n') {
2411 /* return number of characters read so far */
2412 *va_arg(args, int *) = str - buf;
2413 ++fmt;
2414 continue;
2417 if (!*str)
2418 break;
2420 base = 10;
2421 is_sign = false;
2423 switch (*fmt++) {
2424 case 'c':
2426 char *s = (char *)va_arg(args, char*);
2427 if (field_width == -1)
2428 field_width = 1;
2429 do {
2430 *s++ = *str++;
2431 } while (--field_width > 0 && *str);
2432 num++;
2434 continue;
2435 case 's':
2437 char *s = (char *)va_arg(args, char *);
2438 if (field_width == -1)
2439 field_width = SHRT_MAX;
2440 /* first, skip leading white space in buffer */
2441 str = skip_spaces(str);
2443 /* now copy until next white space */
2444 while (*str && !isspace(*str) && field_width--)
2445 *s++ = *str++;
2446 *s = '\0';
2447 num++;
2449 continue;
2450 case 'o':
2451 base = 8;
2452 break;
2453 case 'x':
2454 case 'X':
2455 base = 16;
2456 break;
2457 case 'i':
2458 base = 0;
2459 case 'd':
2460 is_sign = true;
2461 case 'u':
2462 break;
2463 case '%':
2464 /* looking for '%' in str */
2465 if (*str++ != '%')
2466 return num;
2467 continue;
2468 default:
2469 /* invalid format; stop here */
2470 return num;
2473 /* have some sort of integer conversion.
2474 * first, skip white space in buffer.
2476 str = skip_spaces(str);
2478 digit = *str;
2479 if (is_sign && digit == '-')
2480 digit = *(str + 1);
2482 if (!digit
2483 || (base == 16 && !isxdigit(digit))
2484 || (base == 10 && !isdigit(digit))
2485 || (base == 8 && (!isdigit(digit) || digit > '7'))
2486 || (base == 0 && !isdigit(digit)))
2487 break;
2489 if (is_sign)
2490 val.s = qualifier != 'L' ?
2491 simple_strtol(str, &next, base) :
2492 simple_strtoll(str, &next, base);
2493 else
2494 val.u = qualifier != 'L' ?
2495 simple_strtoul(str, &next, base) :
2496 simple_strtoull(str, &next, base);
2498 if (field_width > 0 && next - str > field_width) {
2499 if (base == 0)
2500 _parse_integer_fixup_radix(str, &base);
2501 while (next - str > field_width) {
2502 if (is_sign)
2503 val.s = div_s64(val.s, base);
2504 else
2505 val.u = div_u64(val.u, base);
2506 --next;
2510 switch (qualifier) {
2511 case 'H': /* that's 'hh' in format */
2512 if (is_sign)
2513 *va_arg(args, signed char *) = val.s;
2514 else
2515 *va_arg(args, unsigned char *) = val.u;
2516 break;
2517 case 'h':
2518 if (is_sign)
2519 *va_arg(args, short *) = val.s;
2520 else
2521 *va_arg(args, unsigned short *) = val.u;
2522 break;
2523 case 'l':
2524 if (is_sign)
2525 *va_arg(args, long *) = val.s;
2526 else
2527 *va_arg(args, unsigned long *) = val.u;
2528 break;
2529 case 'L':
2530 if (is_sign)
2531 *va_arg(args, long long *) = val.s;
2532 else
2533 *va_arg(args, unsigned long long *) = val.u;
2534 break;
2535 case 'Z':
2536 case 'z':
2537 *va_arg(args, size_t *) = val.u;
2538 break;
2539 default:
2540 if (is_sign)
2541 *va_arg(args, int *) = val.s;
2542 else
2543 *va_arg(args, unsigned int *) = val.u;
2544 break;
2546 num++;
2548 if (!next)
2549 break;
2550 str = next;
2553 return num;
2555 EXPORT_SYMBOL(vsscanf);
2558 * sscanf - Unformat a buffer into a list of arguments
2559 * @buf: input buffer
2560 * @fmt: formatting of buffer
2561 * @...: resulting arguments
2563 int sscanf(const char *buf, const char *fmt, ...)
2565 va_list args;
2566 int i;
2568 va_start(args, fmt);
2569 i = vsscanf(buf, fmt, args);
2570 va_end(args);
2572 return i;
2574 EXPORT_SYMBOL(sscanf);