Force this on for -next/mm testing purposes.
[linux-2.6/next.git] / lib / vsprintf.c
blobc1a3927326eb90e2c05c841606e2a3dd19b817b9
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>
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/ctype.h>
24 #include <linux/kernel.h>
25 #include <linux/kallsyms.h>
26 #include <linux/uaccess.h>
27 #include <linux/ioport.h>
28 #include <net/addrconf.h>
30 #include <asm/page.h> /* for PAGE_SIZE */
31 #include <asm/div64.h>
32 #include <asm/sections.h> /* for dereference_function_descriptor() */
34 #include "kstrtox.h"
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
42 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
44 unsigned long long result;
45 unsigned int rv;
47 cp = _parse_integer_fixup_radix(cp, &base);
48 rv = _parse_integer(cp, base, &result);
49 /* FIXME */
50 cp += (rv & ~KSTRTOX_OVERFLOW);
52 if (endp)
53 *endp = (char *)cp;
55 return result;
57 EXPORT_SYMBOL(simple_strtoull);
59 /**
60 * simple_strtoul - convert a string to an unsigned long
61 * @cp: The start of the string
62 * @endp: A pointer to the end of the parsed string will be placed here
63 * @base: The number base to use
65 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
67 return simple_strtoull(cp, endp, base);
69 EXPORT_SYMBOL(simple_strtoul);
71 /**
72 * simple_strtol - convert a string to a signed long
73 * @cp: The start of the string
74 * @endp: A pointer to the end of the parsed string will be placed here
75 * @base: The number base to use
77 long simple_strtol(const char *cp, char **endp, unsigned int base)
79 if (*cp == '-')
80 return -simple_strtoul(cp + 1, endp, base);
82 return simple_strtoul(cp, endp, base);
84 EXPORT_SYMBOL(simple_strtol);
86 /**
87 * simple_strtoll - convert a string to a signed long long
88 * @cp: The start of the string
89 * @endp: A pointer to the end of the parsed string will be placed here
90 * @base: The number base to use
92 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
94 if (*cp == '-')
95 return -simple_strtoull(cp + 1, endp, base);
97 return simple_strtoull(cp, endp, base);
99 EXPORT_SYMBOL(simple_strtoll);
101 static noinline_for_stack
102 int skip_atoi(const char **s)
104 int i = 0;
106 while (isdigit(**s))
107 i = i*10 + *((*s)++) - '0';
109 return i;
112 /* Decimal conversion is by far the most typical, and is used
113 * for /proc and /sys data. This directly impacts e.g. top performance
114 * with many processes running. We optimize it for speed
115 * using code from
116 * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
117 * (with permission from the author, Douglas W. Jones). */
119 /* Formats correctly any integer in [0,99999].
120 * Outputs from one to five digits depending on input.
121 * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
122 static noinline_for_stack
123 char *put_dec_trunc(char *buf, unsigned q)
125 unsigned d3, d2, d1, d0;
126 d1 = (q>>4) & 0xf;
127 d2 = (q>>8) & 0xf;
128 d3 = (q>>12);
130 d0 = 6*(d3 + d2 + d1) + (q & 0xf);
131 q = (d0 * 0xcd) >> 11;
132 d0 = d0 - 10*q;
133 *buf++ = d0 + '0'; /* least significant digit */
134 d1 = q + 9*d3 + 5*d2 + d1;
135 if (d1 != 0) {
136 q = (d1 * 0xcd) >> 11;
137 d1 = d1 - 10*q;
138 *buf++ = d1 + '0'; /* next digit */
140 d2 = q + 2*d2;
141 if ((d2 != 0) || (d3 != 0)) {
142 q = (d2 * 0xd) >> 7;
143 d2 = d2 - 10*q;
144 *buf++ = d2 + '0'; /* next digit */
146 d3 = q + 4*d3;
147 if (d3 != 0) {
148 q = (d3 * 0xcd) >> 11;
149 d3 = d3 - 10*q;
150 *buf++ = d3 + '0'; /* next digit */
151 if (q != 0)
152 *buf++ = q + '0'; /* most sign. digit */
157 return buf;
159 /* Same with if's removed. Always emits five digits */
160 static noinline_for_stack
161 char *put_dec_full(char *buf, unsigned q)
163 /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
164 /* but anyway, gcc produces better code with full-sized ints */
165 unsigned d3, d2, d1, d0;
166 d1 = (q>>4) & 0xf;
167 d2 = (q>>8) & 0xf;
168 d3 = (q>>12);
171 * Possible ways to approx. divide by 10
172 * gcc -O2 replaces multiply with shifts and adds
173 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
174 * (x * 0x67) >> 10: 1100111
175 * (x * 0x34) >> 9: 110100 - same
176 * (x * 0x1a) >> 8: 11010 - same
177 * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
179 d0 = 6*(d3 + d2 + d1) + (q & 0xf);
180 q = (d0 * 0xcd) >> 11;
181 d0 = d0 - 10*q;
182 *buf++ = d0 + '0';
183 d1 = q + 9*d3 + 5*d2 + d1;
184 q = (d1 * 0xcd) >> 11;
185 d1 = d1 - 10*q;
186 *buf++ = d1 + '0';
188 d2 = q + 2*d2;
189 q = (d2 * 0xd) >> 7;
190 d2 = d2 - 10*q;
191 *buf++ = d2 + '0';
193 d3 = q + 4*d3;
194 q = (d3 * 0xcd) >> 11; /* - shorter code */
195 /* q = (d3 * 0x67) >> 10; - would also work */
196 d3 = d3 - 10*q;
197 *buf++ = d3 + '0';
198 *buf++ = q + '0';
200 return buf;
202 /* No inlining helps gcc to use registers better */
203 static noinline_for_stack
204 char *put_dec(char *buf, unsigned long long num)
206 while (1) {
207 unsigned rem;
208 if (num < 100000)
209 return put_dec_trunc(buf, num);
210 rem = do_div(num, 100000);
211 buf = put_dec_full(buf, rem);
215 #define ZEROPAD 1 /* pad with zero */
216 #define SIGN 2 /* unsigned/signed long */
217 #define PLUS 4 /* show plus */
218 #define SPACE 8 /* space if plus */
219 #define LEFT 16 /* left justified */
220 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
221 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
223 enum format_type {
224 FORMAT_TYPE_NONE, /* Just a string part */
225 FORMAT_TYPE_WIDTH,
226 FORMAT_TYPE_PRECISION,
227 FORMAT_TYPE_CHAR,
228 FORMAT_TYPE_STR,
229 FORMAT_TYPE_PTR,
230 FORMAT_TYPE_PERCENT_CHAR,
231 FORMAT_TYPE_INVALID,
232 FORMAT_TYPE_LONG_LONG,
233 FORMAT_TYPE_ULONG,
234 FORMAT_TYPE_LONG,
235 FORMAT_TYPE_UBYTE,
236 FORMAT_TYPE_BYTE,
237 FORMAT_TYPE_USHORT,
238 FORMAT_TYPE_SHORT,
239 FORMAT_TYPE_UINT,
240 FORMAT_TYPE_INT,
241 FORMAT_TYPE_NRCHARS,
242 FORMAT_TYPE_SIZE_T,
243 FORMAT_TYPE_PTRDIFF
246 struct printf_spec {
247 u8 type; /* format_type enum */
248 u8 flags; /* flags to number() */
249 u8 base; /* number base, 8, 10 or 16 only */
250 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */
251 s16 field_width; /* width of output field */
252 s16 precision; /* # of digits/chars */
255 static noinline_for_stack
256 char *number(char *buf, char *end, unsigned long long num,
257 struct printf_spec spec)
259 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
260 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
262 char tmp[66];
263 char sign;
264 char locase;
265 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
266 int i;
268 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
269 * produces same digits or (maybe lowercased) letters */
270 locase = (spec.flags & SMALL);
271 if (spec.flags & LEFT)
272 spec.flags &= ~ZEROPAD;
273 sign = 0;
274 if (spec.flags & SIGN) {
275 if ((signed long long)num < 0) {
276 sign = '-';
277 num = -(signed long long)num;
278 spec.field_width--;
279 } else if (spec.flags & PLUS) {
280 sign = '+';
281 spec.field_width--;
282 } else if (spec.flags & SPACE) {
283 sign = ' ';
284 spec.field_width--;
287 if (need_pfx) {
288 spec.field_width--;
289 if (spec.base == 16)
290 spec.field_width--;
293 /* generate full string in tmp[], in reverse order */
294 i = 0;
295 if (num == 0)
296 tmp[i++] = '0';
297 /* Generic code, for any base:
298 else do {
299 tmp[i++] = (digits[do_div(num,base)] | locase);
300 } while (num != 0);
302 else if (spec.base != 10) { /* 8 or 16 */
303 int mask = spec.base - 1;
304 int shift = 3;
306 if (spec.base == 16)
307 shift = 4;
308 do {
309 tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
310 num >>= shift;
311 } while (num);
312 } else { /* base 10 */
313 i = put_dec(tmp, num) - tmp;
316 /* printing 100 using %2d gives "100", not "00" */
317 if (i > spec.precision)
318 spec.precision = i;
319 /* leading space padding */
320 spec.field_width -= spec.precision;
321 if (!(spec.flags & (ZEROPAD+LEFT))) {
322 while (--spec.field_width >= 0) {
323 if (buf < end)
324 *buf = ' ';
325 ++buf;
328 /* sign */
329 if (sign) {
330 if (buf < end)
331 *buf = sign;
332 ++buf;
334 /* "0x" / "0" prefix */
335 if (need_pfx) {
336 if (buf < end)
337 *buf = '0';
338 ++buf;
339 if (spec.base == 16) {
340 if (buf < end)
341 *buf = ('X' | locase);
342 ++buf;
345 /* zero or space padding */
346 if (!(spec.flags & LEFT)) {
347 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
348 while (--spec.field_width >= 0) {
349 if (buf < end)
350 *buf = c;
351 ++buf;
354 /* hmm even more zero padding? */
355 while (i <= --spec.precision) {
356 if (buf < end)
357 *buf = '0';
358 ++buf;
360 /* actual digits of result */
361 while (--i >= 0) {
362 if (buf < end)
363 *buf = tmp[i];
364 ++buf;
366 /* trailing space padding */
367 while (--spec.field_width >= 0) {
368 if (buf < end)
369 *buf = ' ';
370 ++buf;
373 return buf;
376 static noinline_for_stack
377 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
379 int len, i;
381 if ((unsigned long)s < PAGE_SIZE)
382 s = "(null)";
384 len = strnlen(s, spec.precision);
386 if (!(spec.flags & LEFT)) {
387 while (len < spec.field_width--) {
388 if (buf < end)
389 *buf = ' ';
390 ++buf;
393 for (i = 0; i < len; ++i) {
394 if (buf < end)
395 *buf = *s;
396 ++buf; ++s;
398 while (len < spec.field_width--) {
399 if (buf < end)
400 *buf = ' ';
401 ++buf;
404 return buf;
407 static noinline_for_stack
408 char *symbol_string(char *buf, char *end, void *ptr,
409 struct printf_spec spec, char ext)
411 unsigned long value = (unsigned long) ptr;
412 #ifdef CONFIG_KALLSYMS
413 char sym[KSYM_SYMBOL_LEN];
414 if (ext == 'B')
415 sprint_backtrace(sym, value);
416 else if (ext != 'f' && ext != 's')
417 sprint_symbol(sym, value);
418 else
419 kallsyms_lookup(value, NULL, NULL, NULL, sym);
421 return string(buf, end, sym, spec);
422 #else
423 spec.field_width = 2 * sizeof(void *);
424 spec.flags |= SPECIAL | SMALL | ZEROPAD;
425 spec.base = 16;
427 return number(buf, end, value, spec);
428 #endif
431 static noinline_for_stack
432 char *resource_string(char *buf, char *end, struct resource *res,
433 struct printf_spec spec, const char *fmt)
435 #ifndef IO_RSRC_PRINTK_SIZE
436 #define IO_RSRC_PRINTK_SIZE 6
437 #endif
439 #ifndef MEM_RSRC_PRINTK_SIZE
440 #define MEM_RSRC_PRINTK_SIZE 10
441 #endif
442 static const struct printf_spec io_spec = {
443 .base = 16,
444 .field_width = IO_RSRC_PRINTK_SIZE,
445 .precision = -1,
446 .flags = SPECIAL | SMALL | ZEROPAD,
448 static const struct printf_spec mem_spec = {
449 .base = 16,
450 .field_width = MEM_RSRC_PRINTK_SIZE,
451 .precision = -1,
452 .flags = SPECIAL | SMALL | ZEROPAD,
454 static const struct printf_spec bus_spec = {
455 .base = 16,
456 .field_width = 2,
457 .precision = -1,
458 .flags = SMALL | ZEROPAD,
460 static const struct printf_spec dec_spec = {
461 .base = 10,
462 .precision = -1,
463 .flags = 0,
465 static const struct printf_spec str_spec = {
466 .field_width = -1,
467 .precision = 10,
468 .flags = LEFT,
470 static const struct printf_spec flag_spec = {
471 .base = 16,
472 .precision = -1,
473 .flags = SPECIAL | SMALL,
476 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
477 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
478 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
479 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
480 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
481 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
482 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
483 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
485 char *p = sym, *pend = sym + sizeof(sym);
486 int decode = (fmt[0] == 'R') ? 1 : 0;
487 const struct printf_spec *specp;
489 *p++ = '[';
490 if (res->flags & IORESOURCE_IO) {
491 p = string(p, pend, "io ", str_spec);
492 specp = &io_spec;
493 } else if (res->flags & IORESOURCE_MEM) {
494 p = string(p, pend, "mem ", str_spec);
495 specp = &mem_spec;
496 } else if (res->flags & IORESOURCE_IRQ) {
497 p = string(p, pend, "irq ", str_spec);
498 specp = &dec_spec;
499 } else if (res->flags & IORESOURCE_DMA) {
500 p = string(p, pend, "dma ", str_spec);
501 specp = &dec_spec;
502 } else if (res->flags & IORESOURCE_BUS) {
503 p = string(p, pend, "bus ", str_spec);
504 specp = &bus_spec;
505 } else {
506 p = string(p, pend, "??? ", str_spec);
507 specp = &mem_spec;
508 decode = 0;
510 p = number(p, pend, res->start, *specp);
511 if (res->start != res->end) {
512 *p++ = '-';
513 p = number(p, pend, res->end, *specp);
515 if (decode) {
516 if (res->flags & IORESOURCE_MEM_64)
517 p = string(p, pend, " 64bit", str_spec);
518 if (res->flags & IORESOURCE_PREFETCH)
519 p = string(p, pend, " pref", str_spec);
520 if (res->flags & IORESOURCE_WINDOW)
521 p = string(p, pend, " window", str_spec);
522 if (res->flags & IORESOURCE_DISABLED)
523 p = string(p, pend, " disabled", str_spec);
524 } else {
525 p = string(p, pend, " flags ", str_spec);
526 p = number(p, pend, res->flags, flag_spec);
528 *p++ = ']';
529 *p = '\0';
531 return string(buf, end, sym, spec);
534 static noinline_for_stack
535 char *mac_address_string(char *buf, char *end, u8 *addr,
536 struct printf_spec spec, const char *fmt)
538 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
539 char *p = mac_addr;
540 int i;
541 char separator;
543 if (fmt[1] == 'F') { /* FDDI canonical format */
544 separator = '-';
545 } else {
546 separator = ':';
549 for (i = 0; i < 6; i++) {
550 p = pack_hex_byte(p, addr[i]);
551 if (fmt[0] == 'M' && i != 5)
552 *p++ = separator;
554 *p = '\0';
556 return string(buf, end, mac_addr, spec);
559 static noinline_for_stack
560 char *ip4_string(char *p, const u8 *addr, const char *fmt)
562 int i;
563 bool leading_zeros = (fmt[0] == 'i');
564 int index;
565 int step;
567 switch (fmt[2]) {
568 case 'h':
569 #ifdef __BIG_ENDIAN
570 index = 0;
571 step = 1;
572 #else
573 index = 3;
574 step = -1;
575 #endif
576 break;
577 case 'l':
578 index = 3;
579 step = -1;
580 break;
581 case 'n':
582 case 'b':
583 default:
584 index = 0;
585 step = 1;
586 break;
588 for (i = 0; i < 4; i++) {
589 char temp[3]; /* hold each IP quad in reverse order */
590 int digits = put_dec_trunc(temp, addr[index]) - temp;
591 if (leading_zeros) {
592 if (digits < 3)
593 *p++ = '0';
594 if (digits < 2)
595 *p++ = '0';
597 /* reverse the digits in the quad */
598 while (digits--)
599 *p++ = temp[digits];
600 if (i < 3)
601 *p++ = '.';
602 index += step;
604 *p = '\0';
606 return p;
609 static noinline_for_stack
610 char *ip6_compressed_string(char *p, const char *addr)
612 int i, j, range;
613 unsigned char zerolength[8];
614 int longest = 1;
615 int colonpos = -1;
616 u16 word;
617 u8 hi, lo;
618 bool needcolon = false;
619 bool useIPv4;
620 struct in6_addr in6;
622 memcpy(&in6, addr, sizeof(struct in6_addr));
624 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
626 memset(zerolength, 0, sizeof(zerolength));
628 if (useIPv4)
629 range = 6;
630 else
631 range = 8;
633 /* find position of longest 0 run */
634 for (i = 0; i < range; i++) {
635 for (j = i; j < range; j++) {
636 if (in6.s6_addr16[j] != 0)
637 break;
638 zerolength[i]++;
641 for (i = 0; i < range; i++) {
642 if (zerolength[i] > longest) {
643 longest = zerolength[i];
644 colonpos = i;
647 if (longest == 1) /* don't compress a single 0 */
648 colonpos = -1;
650 /* emit address */
651 for (i = 0; i < range; i++) {
652 if (i == colonpos) {
653 if (needcolon || i == 0)
654 *p++ = ':';
655 *p++ = ':';
656 needcolon = false;
657 i += longest - 1;
658 continue;
660 if (needcolon) {
661 *p++ = ':';
662 needcolon = false;
664 /* hex u16 without leading 0s */
665 word = ntohs(in6.s6_addr16[i]);
666 hi = word >> 8;
667 lo = word & 0xff;
668 if (hi) {
669 if (hi > 0x0f)
670 p = pack_hex_byte(p, hi);
671 else
672 *p++ = hex_asc_lo(hi);
673 p = pack_hex_byte(p, lo);
675 else if (lo > 0x0f)
676 p = pack_hex_byte(p, lo);
677 else
678 *p++ = hex_asc_lo(lo);
679 needcolon = true;
682 if (useIPv4) {
683 if (needcolon)
684 *p++ = ':';
685 p = ip4_string(p, &in6.s6_addr[12], "I4");
687 *p = '\0';
689 return p;
692 static noinline_for_stack
693 char *ip6_string(char *p, const char *addr, const char *fmt)
695 int i;
697 for (i = 0; i < 8; i++) {
698 p = pack_hex_byte(p, *addr++);
699 p = pack_hex_byte(p, *addr++);
700 if (fmt[0] == 'I' && i != 7)
701 *p++ = ':';
703 *p = '\0';
705 return p;
708 static noinline_for_stack
709 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
710 struct printf_spec spec, const char *fmt)
712 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
714 if (fmt[0] == 'I' && fmt[2] == 'c')
715 ip6_compressed_string(ip6_addr, addr);
716 else
717 ip6_string(ip6_addr, addr, fmt);
719 return string(buf, end, ip6_addr, spec);
722 static noinline_for_stack
723 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
724 struct printf_spec spec, const char *fmt)
726 char ip4_addr[sizeof("255.255.255.255")];
728 ip4_string(ip4_addr, addr, fmt);
730 return string(buf, end, ip4_addr, spec);
733 static noinline_for_stack
734 char *uuid_string(char *buf, char *end, const u8 *addr,
735 struct printf_spec spec, const char *fmt)
737 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
738 char *p = uuid;
739 int i;
740 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
741 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
742 const u8 *index = be;
743 bool uc = false;
745 switch (*(++fmt)) {
746 case 'L':
747 uc = true; /* fall-through */
748 case 'l':
749 index = le;
750 break;
751 case 'B':
752 uc = true;
753 break;
756 for (i = 0; i < 16; i++) {
757 p = pack_hex_byte(p, addr[index[i]]);
758 switch (i) {
759 case 3:
760 case 5:
761 case 7:
762 case 9:
763 *p++ = '-';
764 break;
768 *p = 0;
770 if (uc) {
771 p = uuid;
772 do {
773 *p = toupper(*p);
774 } while (*(++p));
777 return string(buf, end, uuid, spec);
780 int kptr_restrict __read_mostly;
783 * Show a '%p' thing. A kernel extension is that the '%p' is followed
784 * by an extra set of alphanumeric characters that are extended format
785 * specifiers.
787 * Right now we handle:
789 * - 'F' For symbolic function descriptor pointers with offset
790 * - 'f' For simple symbolic function names without offset
791 * - 'S' For symbolic direct pointers with offset
792 * - 's' For symbolic direct pointers without offset
793 * - 'B' For backtraced symbolic direct pointers with offset
794 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
795 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
796 * - 'M' For a 6-byte MAC address, it prints the address in the
797 * usual colon-separated hex notation
798 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
799 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
800 * with a dash-separated hex notation
801 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
802 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
803 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
804 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
805 * IPv6 omits the colons (01020304...0f)
806 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
807 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
808 * - 'I6c' for IPv6 addresses printed as specified by
809 * http://tools.ietf.org/html/rfc5952
810 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
811 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
812 * Options for %pU are:
813 * b big endian lower case hex (default)
814 * B big endian UPPER case hex
815 * l little endian lower case hex
816 * L little endian UPPER case hex
817 * big endian output byte order is:
818 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
819 * little endian output byte order is:
820 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
821 * - 'V' For a struct va_format which contains a format string * and va_list *,
822 * call vsnprintf(->format, *->va_list).
823 * Implements a "recursive vsnprintf".
824 * Do not use this feature without some mechanism to verify the
825 * correctness of the format string and va_list arguments.
826 * - 'K' For a kernel pointer that should be hidden from unprivileged users
828 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
829 * function pointers are really function descriptors, which contain a
830 * pointer to the real address.
832 static noinline_for_stack
833 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
834 struct printf_spec spec)
836 if (!ptr && *fmt != 'K') {
838 * Print (null) with the same width as a pointer so it makes
839 * tabular output look nice.
841 if (spec.field_width == -1)
842 spec.field_width = 2 * sizeof(void *);
843 return string(buf, end, "(null)", spec);
846 switch (*fmt) {
847 case 'F':
848 case 'f':
849 ptr = dereference_function_descriptor(ptr);
850 /* Fallthrough */
851 case 'S':
852 case 's':
853 case 'B':
854 return symbol_string(buf, end, ptr, spec, *fmt);
855 case 'R':
856 case 'r':
857 return resource_string(buf, end, ptr, spec, fmt);
858 case 'M': /* Colon separated: 00:01:02:03:04:05 */
859 case 'm': /* Contiguous: 000102030405 */
860 /* [mM]F (FDDI, bit reversed) */
861 return mac_address_string(buf, end, ptr, spec, fmt);
862 case 'I': /* Formatted IP supported
863 * 4: 1.2.3.4
864 * 6: 0001:0203:...:0708
865 * 6c: 1::708 or 1::1.2.3.4
867 case 'i': /* Contiguous:
868 * 4: 001.002.003.004
869 * 6: 000102...0f
871 switch (fmt[1]) {
872 case '6':
873 return ip6_addr_string(buf, end, ptr, spec, fmt);
874 case '4':
875 return ip4_addr_string(buf, end, ptr, spec, fmt);
877 break;
878 case 'U':
879 return uuid_string(buf, end, ptr, spec, fmt);
880 case 'V':
881 return buf + vsnprintf(buf, end > buf ? end - buf : 0,
882 ((struct va_format *)ptr)->fmt,
883 *(((struct va_format *)ptr)->va));
884 case 'K':
886 * %pK cannot be used in IRQ context because its test
887 * for CAP_SYSLOG would be meaningless.
889 if (in_irq() || in_serving_softirq() || in_nmi()) {
890 if (spec.field_width == -1)
891 spec.field_width = 2 * sizeof(void *);
892 return string(buf, end, "pK-error", spec);
894 if (!((kptr_restrict == 0) ||
895 (kptr_restrict == 1 &&
896 has_capability_noaudit(current, CAP_SYSLOG))))
897 ptr = NULL;
898 break;
900 spec.flags |= SMALL;
901 if (spec.field_width == -1) {
902 spec.field_width = 2 * sizeof(void *);
903 spec.flags |= ZEROPAD;
905 spec.base = 16;
907 return number(buf, end, (unsigned long) ptr, spec);
911 * Helper function to decode printf style format.
912 * Each call decode a token from the format and return the
913 * number of characters read (or likely the delta where it wants
914 * to go on the next call).
915 * The decoded token is returned through the parameters
917 * 'h', 'l', or 'L' for integer fields
918 * 'z' support added 23/7/1999 S.H.
919 * 'z' changed to 'Z' --davidm 1/25/99
920 * 't' added for ptrdiff_t
922 * @fmt: the format string
923 * @type of the token returned
924 * @flags: various flags such as +, -, # tokens..
925 * @field_width: overwritten width
926 * @base: base of the number (octal, hex, ...)
927 * @precision: precision of a number
928 * @qualifier: qualifier of a number (long, size_t, ...)
930 static noinline_for_stack
931 int format_decode(const char *fmt, struct printf_spec *spec)
933 const char *start = fmt;
935 /* we finished early by reading the field width */
936 if (spec->type == FORMAT_TYPE_WIDTH) {
937 if (spec->field_width < 0) {
938 spec->field_width = -spec->field_width;
939 spec->flags |= LEFT;
941 spec->type = FORMAT_TYPE_NONE;
942 goto precision;
945 /* we finished early by reading the precision */
946 if (spec->type == FORMAT_TYPE_PRECISION) {
947 if (spec->precision < 0)
948 spec->precision = 0;
950 spec->type = FORMAT_TYPE_NONE;
951 goto qualifier;
954 /* By default */
955 spec->type = FORMAT_TYPE_NONE;
957 for (; *fmt ; ++fmt) {
958 if (*fmt == '%')
959 break;
962 /* Return the current non-format string */
963 if (fmt != start || !*fmt)
964 return fmt - start;
966 /* Process flags */
967 spec->flags = 0;
969 while (1) { /* this also skips first '%' */
970 bool found = true;
972 ++fmt;
974 switch (*fmt) {
975 case '-': spec->flags |= LEFT; break;
976 case '+': spec->flags |= PLUS; break;
977 case ' ': spec->flags |= SPACE; break;
978 case '#': spec->flags |= SPECIAL; break;
979 case '0': spec->flags |= ZEROPAD; break;
980 default: found = false;
983 if (!found)
984 break;
987 /* get field width */
988 spec->field_width = -1;
990 if (isdigit(*fmt))
991 spec->field_width = skip_atoi(&fmt);
992 else if (*fmt == '*') {
993 /* it's the next argument */
994 spec->type = FORMAT_TYPE_WIDTH;
995 return ++fmt - start;
998 precision:
999 /* get the precision */
1000 spec->precision = -1;
1001 if (*fmt == '.') {
1002 ++fmt;
1003 if (isdigit(*fmt)) {
1004 spec->precision = skip_atoi(&fmt);
1005 if (spec->precision < 0)
1006 spec->precision = 0;
1007 } else if (*fmt == '*') {
1008 /* it's the next argument */
1009 spec->type = FORMAT_TYPE_PRECISION;
1010 return ++fmt - start;
1014 qualifier:
1015 /* get the conversion qualifier */
1016 spec->qualifier = -1;
1017 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1018 _tolower(*fmt) == 'z' || *fmt == 't') {
1019 spec->qualifier = *fmt++;
1020 if (unlikely(spec->qualifier == *fmt)) {
1021 if (spec->qualifier == 'l') {
1022 spec->qualifier = 'L';
1023 ++fmt;
1024 } else if (spec->qualifier == 'h') {
1025 spec->qualifier = 'H';
1026 ++fmt;
1031 /* default base */
1032 spec->base = 10;
1033 switch (*fmt) {
1034 case 'c':
1035 spec->type = FORMAT_TYPE_CHAR;
1036 return ++fmt - start;
1038 case 's':
1039 spec->type = FORMAT_TYPE_STR;
1040 return ++fmt - start;
1042 case 'p':
1043 spec->type = FORMAT_TYPE_PTR;
1044 return fmt - start;
1045 /* skip alnum */
1047 case 'n':
1048 spec->type = FORMAT_TYPE_NRCHARS;
1049 return ++fmt - start;
1051 case '%':
1052 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1053 return ++fmt - start;
1055 /* integer number formats - set up the flags and "break" */
1056 case 'o':
1057 spec->base = 8;
1058 break;
1060 case 'x':
1061 spec->flags |= SMALL;
1063 case 'X':
1064 spec->base = 16;
1065 break;
1067 case 'd':
1068 case 'i':
1069 spec->flags |= SIGN;
1070 case 'u':
1071 break;
1073 default:
1074 spec->type = FORMAT_TYPE_INVALID;
1075 return fmt - start;
1078 if (spec->qualifier == 'L')
1079 spec->type = FORMAT_TYPE_LONG_LONG;
1080 else if (spec->qualifier == 'l') {
1081 if (spec->flags & SIGN)
1082 spec->type = FORMAT_TYPE_LONG;
1083 else
1084 spec->type = FORMAT_TYPE_ULONG;
1085 } else if (_tolower(spec->qualifier) == 'z') {
1086 spec->type = FORMAT_TYPE_SIZE_T;
1087 } else if (spec->qualifier == 't') {
1088 spec->type = FORMAT_TYPE_PTRDIFF;
1089 } else if (spec->qualifier == 'H') {
1090 if (spec->flags & SIGN)
1091 spec->type = FORMAT_TYPE_BYTE;
1092 else
1093 spec->type = FORMAT_TYPE_UBYTE;
1094 } else if (spec->qualifier == 'h') {
1095 if (spec->flags & SIGN)
1096 spec->type = FORMAT_TYPE_SHORT;
1097 else
1098 spec->type = FORMAT_TYPE_USHORT;
1099 } else {
1100 if (spec->flags & SIGN)
1101 spec->type = FORMAT_TYPE_INT;
1102 else
1103 spec->type = FORMAT_TYPE_UINT;
1106 return ++fmt - start;
1110 * vsnprintf - Format a string and place it in a buffer
1111 * @buf: The buffer to place the result into
1112 * @size: The size of the buffer, including the trailing null space
1113 * @fmt: The format string to use
1114 * @args: Arguments for the format string
1116 * This function follows C99 vsnprintf, but has some extensions:
1117 * %pS output the name of a text symbol with offset
1118 * %ps output the name of a text symbol without offset
1119 * %pF output the name of a function pointer with its offset
1120 * %pf output the name of a function pointer without its offset
1121 * %pB output the name of a backtrace symbol with its offset
1122 * %pR output the address range in a struct resource with decoded flags
1123 * %pr output the address range in a struct resource with raw flags
1124 * %pM output a 6-byte MAC address with colons
1125 * %pm output a 6-byte MAC address without colons
1126 * %pI4 print an IPv4 address without leading zeros
1127 * %pi4 print an IPv4 address with leading zeros
1128 * %pI6 print an IPv6 address with colons
1129 * %pi6 print an IPv6 address without colons
1130 * %pI6c print an IPv6 address as specified by RFC 5952
1131 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1132 * case.
1133 * %n is ignored
1135 * The return value is the number of characters which would
1136 * be generated for the given input, excluding the trailing
1137 * '\0', as per ISO C99. If you want to have the exact
1138 * number of characters written into @buf as return value
1139 * (not including the trailing '\0'), use vscnprintf(). If the
1140 * return is greater than or equal to @size, the resulting
1141 * string is truncated.
1143 * If you're not already dealing with a va_list consider using snprintf().
1145 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1147 unsigned long long num;
1148 char *str, *end;
1149 struct printf_spec spec = {0};
1151 /* Reject out-of-range values early. Large positive sizes are
1152 used for unknown buffer sizes. */
1153 if (WARN_ON_ONCE((int) size < 0))
1154 return 0;
1156 str = buf;
1157 end = buf + size;
1159 /* Make sure end is always >= buf */
1160 if (end < buf) {
1161 end = ((void *)-1);
1162 size = end - buf;
1165 while (*fmt) {
1166 const char *old_fmt = fmt;
1167 int read = format_decode(fmt, &spec);
1169 fmt += read;
1171 switch (spec.type) {
1172 case FORMAT_TYPE_NONE: {
1173 int copy = read;
1174 if (str < end) {
1175 if (copy > end - str)
1176 copy = end - str;
1177 memcpy(str, old_fmt, copy);
1179 str += read;
1180 break;
1183 case FORMAT_TYPE_WIDTH:
1184 spec.field_width = va_arg(args, int);
1185 break;
1187 case FORMAT_TYPE_PRECISION:
1188 spec.precision = va_arg(args, int);
1189 break;
1191 case FORMAT_TYPE_CHAR: {
1192 char c;
1194 if (!(spec.flags & LEFT)) {
1195 while (--spec.field_width > 0) {
1196 if (str < end)
1197 *str = ' ';
1198 ++str;
1202 c = (unsigned char) va_arg(args, int);
1203 if (str < end)
1204 *str = c;
1205 ++str;
1206 while (--spec.field_width > 0) {
1207 if (str < end)
1208 *str = ' ';
1209 ++str;
1211 break;
1214 case FORMAT_TYPE_STR:
1215 str = string(str, end, va_arg(args, char *), spec);
1216 break;
1218 case FORMAT_TYPE_PTR:
1219 str = pointer(fmt+1, str, end, va_arg(args, void *),
1220 spec);
1221 while (isalnum(*fmt))
1222 fmt++;
1223 break;
1225 case FORMAT_TYPE_PERCENT_CHAR:
1226 if (str < end)
1227 *str = '%';
1228 ++str;
1229 break;
1231 case FORMAT_TYPE_INVALID:
1232 if (str < end)
1233 *str = '%';
1234 ++str;
1235 break;
1237 case FORMAT_TYPE_NRCHARS: {
1238 u8 qualifier = spec.qualifier;
1240 if (qualifier == 'l') {
1241 long *ip = va_arg(args, long *);
1242 *ip = (str - buf);
1243 } else if (_tolower(qualifier) == 'z') {
1244 size_t *ip = va_arg(args, size_t *);
1245 *ip = (str - buf);
1246 } else {
1247 int *ip = va_arg(args, int *);
1248 *ip = (str - buf);
1250 break;
1253 default:
1254 switch (spec.type) {
1255 case FORMAT_TYPE_LONG_LONG:
1256 num = va_arg(args, long long);
1257 break;
1258 case FORMAT_TYPE_ULONG:
1259 num = va_arg(args, unsigned long);
1260 break;
1261 case FORMAT_TYPE_LONG:
1262 num = va_arg(args, long);
1263 break;
1264 case FORMAT_TYPE_SIZE_T:
1265 num = va_arg(args, size_t);
1266 break;
1267 case FORMAT_TYPE_PTRDIFF:
1268 num = va_arg(args, ptrdiff_t);
1269 break;
1270 case FORMAT_TYPE_UBYTE:
1271 num = (unsigned char) va_arg(args, int);
1272 break;
1273 case FORMAT_TYPE_BYTE:
1274 num = (signed char) va_arg(args, int);
1275 break;
1276 case FORMAT_TYPE_USHORT:
1277 num = (unsigned short) va_arg(args, int);
1278 break;
1279 case FORMAT_TYPE_SHORT:
1280 num = (short) va_arg(args, int);
1281 break;
1282 case FORMAT_TYPE_INT:
1283 num = (int) va_arg(args, int);
1284 break;
1285 default:
1286 num = va_arg(args, unsigned int);
1289 str = number(str, end, num, spec);
1293 if (size > 0) {
1294 if (str < end)
1295 *str = '\0';
1296 else
1297 end[-1] = '\0';
1300 /* the trailing null byte doesn't count towards the total */
1301 return str-buf;
1304 EXPORT_SYMBOL(vsnprintf);
1307 * vscnprintf - Format a string and place it in a buffer
1308 * @buf: The buffer to place the result into
1309 * @size: The size of the buffer, including the trailing null space
1310 * @fmt: The format string to use
1311 * @args: Arguments for the format string
1313 * The return value is the number of characters which have been written into
1314 * the @buf not including the trailing '\0'. If @size is == 0 the function
1315 * returns 0.
1317 * If you're not already dealing with a va_list consider using scnprintf().
1319 * See the vsnprintf() documentation for format string extensions over C99.
1321 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1323 int i;
1325 i = vsnprintf(buf, size, fmt, args);
1327 if (likely(i < size))
1328 return i;
1329 if (size != 0)
1330 return size - 1;
1331 return 0;
1333 EXPORT_SYMBOL(vscnprintf);
1336 * snprintf - Format a string and place it in a buffer
1337 * @buf: The buffer to place the result into
1338 * @size: The size of the buffer, including the trailing null space
1339 * @fmt: The format string to use
1340 * @...: Arguments for the format string
1342 * The return value is the number of characters which would be
1343 * generated for the given input, excluding the trailing null,
1344 * as per ISO C99. If the return is greater than or equal to
1345 * @size, the resulting string is truncated.
1347 * See the vsnprintf() documentation for format string extensions over C99.
1349 int snprintf(char *buf, size_t size, const char *fmt, ...)
1351 va_list args;
1352 int i;
1354 va_start(args, fmt);
1355 i = vsnprintf(buf, size, fmt, args);
1356 va_end(args);
1358 return i;
1360 EXPORT_SYMBOL(snprintf);
1363 * scnprintf - Format a string and place it in a buffer
1364 * @buf: The buffer to place the result into
1365 * @size: The size of the buffer, including the trailing null space
1366 * @fmt: The format string to use
1367 * @...: Arguments for the format string
1369 * The return value is the number of characters written into @buf not including
1370 * the trailing '\0'. If @size is == 0 the function returns 0.
1373 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1375 va_list args;
1376 int i;
1378 va_start(args, fmt);
1379 i = vscnprintf(buf, size, fmt, args);
1380 va_end(args);
1382 return i;
1384 EXPORT_SYMBOL(scnprintf);
1387 * vsprintf - Format a string and place it in a buffer
1388 * @buf: The buffer to place the result into
1389 * @fmt: The format string to use
1390 * @args: Arguments for the format string
1392 * The function returns the number of characters written
1393 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1394 * buffer overflows.
1396 * If you're not already dealing with a va_list consider using sprintf().
1398 * See the vsnprintf() documentation for format string extensions over C99.
1400 int vsprintf(char *buf, const char *fmt, va_list args)
1402 return vsnprintf(buf, INT_MAX, fmt, args);
1404 EXPORT_SYMBOL(vsprintf);
1407 * sprintf - Format a string and place it in a buffer
1408 * @buf: The buffer to place the result into
1409 * @fmt: The format string to use
1410 * @...: Arguments for the format string
1412 * The function returns the number of characters written
1413 * into @buf. Use snprintf() or scnprintf() in order to avoid
1414 * buffer overflows.
1416 * See the vsnprintf() documentation for format string extensions over C99.
1418 int sprintf(char *buf, const char *fmt, ...)
1420 va_list args;
1421 int i;
1423 va_start(args, fmt);
1424 i = vsnprintf(buf, INT_MAX, fmt, args);
1425 va_end(args);
1427 return i;
1429 EXPORT_SYMBOL(sprintf);
1431 #ifdef CONFIG_BINARY_PRINTF
1433 * bprintf service:
1434 * vbin_printf() - VA arguments to binary data
1435 * bstr_printf() - Binary data to text string
1439 * vbin_printf - Parse a format string and place args' binary value in a buffer
1440 * @bin_buf: The buffer to place args' binary value
1441 * @size: The size of the buffer(by words(32bits), not characters)
1442 * @fmt: The format string to use
1443 * @args: Arguments for the format string
1445 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1446 * is skiped.
1448 * The return value is the number of words(32bits) which would be generated for
1449 * the given input.
1451 * NOTE:
1452 * If the return value is greater than @size, the resulting bin_buf is NOT
1453 * valid for bstr_printf().
1455 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1457 struct printf_spec spec = {0};
1458 char *str, *end;
1460 str = (char *)bin_buf;
1461 end = (char *)(bin_buf + size);
1463 #define save_arg(type) \
1464 do { \
1465 if (sizeof(type) == 8) { \
1466 unsigned long long value; \
1467 str = PTR_ALIGN(str, sizeof(u32)); \
1468 value = va_arg(args, unsigned long long); \
1469 if (str + sizeof(type) <= end) { \
1470 *(u32 *)str = *(u32 *)&value; \
1471 *(u32 *)(str + 4) = *((u32 *)&value + 1); \
1473 } else { \
1474 unsigned long value; \
1475 str = PTR_ALIGN(str, sizeof(type)); \
1476 value = va_arg(args, int); \
1477 if (str + sizeof(type) <= end) \
1478 *(typeof(type) *)str = (type)value; \
1480 str += sizeof(type); \
1481 } while (0)
1483 while (*fmt) {
1484 int read = format_decode(fmt, &spec);
1486 fmt += read;
1488 switch (spec.type) {
1489 case FORMAT_TYPE_NONE:
1490 case FORMAT_TYPE_INVALID:
1491 case FORMAT_TYPE_PERCENT_CHAR:
1492 break;
1494 case FORMAT_TYPE_WIDTH:
1495 case FORMAT_TYPE_PRECISION:
1496 save_arg(int);
1497 break;
1499 case FORMAT_TYPE_CHAR:
1500 save_arg(char);
1501 break;
1503 case FORMAT_TYPE_STR: {
1504 const char *save_str = va_arg(args, char *);
1505 size_t len;
1507 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1508 || (unsigned long)save_str < PAGE_SIZE)
1509 save_str = "(null)";
1510 len = strlen(save_str) + 1;
1511 if (str + len < end)
1512 memcpy(str, save_str, len);
1513 str += len;
1514 break;
1517 case FORMAT_TYPE_PTR:
1518 save_arg(void *);
1519 /* skip all alphanumeric pointer suffixes */
1520 while (isalnum(*fmt))
1521 fmt++;
1522 break;
1524 case FORMAT_TYPE_NRCHARS: {
1525 /* skip %n 's argument */
1526 u8 qualifier = spec.qualifier;
1527 void *skip_arg;
1528 if (qualifier == 'l')
1529 skip_arg = va_arg(args, long *);
1530 else if (_tolower(qualifier) == 'z')
1531 skip_arg = va_arg(args, size_t *);
1532 else
1533 skip_arg = va_arg(args, int *);
1534 break;
1537 default:
1538 switch (spec.type) {
1540 case FORMAT_TYPE_LONG_LONG:
1541 save_arg(long long);
1542 break;
1543 case FORMAT_TYPE_ULONG:
1544 case FORMAT_TYPE_LONG:
1545 save_arg(unsigned long);
1546 break;
1547 case FORMAT_TYPE_SIZE_T:
1548 save_arg(size_t);
1549 break;
1550 case FORMAT_TYPE_PTRDIFF:
1551 save_arg(ptrdiff_t);
1552 break;
1553 case FORMAT_TYPE_UBYTE:
1554 case FORMAT_TYPE_BYTE:
1555 save_arg(char);
1556 break;
1557 case FORMAT_TYPE_USHORT:
1558 case FORMAT_TYPE_SHORT:
1559 save_arg(short);
1560 break;
1561 default:
1562 save_arg(int);
1567 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1568 #undef save_arg
1570 EXPORT_SYMBOL_GPL(vbin_printf);
1573 * bstr_printf - Format a string from binary arguments and place it in a buffer
1574 * @buf: The buffer to place the result into
1575 * @size: The size of the buffer, including the trailing null space
1576 * @fmt: The format string to use
1577 * @bin_buf: Binary arguments for the format string
1579 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1580 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1581 * a binary buffer that generated by vbin_printf.
1583 * The format follows C99 vsnprintf, but has some extensions:
1584 * see vsnprintf comment for details.
1586 * The return value is the number of characters which would
1587 * be generated for the given input, excluding the trailing
1588 * '\0', as per ISO C99. If you want to have the exact
1589 * number of characters written into @buf as return value
1590 * (not including the trailing '\0'), use vscnprintf(). If the
1591 * return is greater than or equal to @size, the resulting
1592 * string is truncated.
1594 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1596 struct printf_spec spec = {0};
1597 char *str, *end;
1598 const char *args = (const char *)bin_buf;
1600 if (WARN_ON_ONCE((int) size < 0))
1601 return 0;
1603 str = buf;
1604 end = buf + size;
1606 #define get_arg(type) \
1607 ({ \
1608 typeof(type) value; \
1609 if (sizeof(type) == 8) { \
1610 args = PTR_ALIGN(args, sizeof(u32)); \
1611 *(u32 *)&value = *(u32 *)args; \
1612 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
1613 } else { \
1614 args = PTR_ALIGN(args, sizeof(type)); \
1615 value = *(typeof(type) *)args; \
1617 args += sizeof(type); \
1618 value; \
1621 /* Make sure end is always >= buf */
1622 if (end < buf) {
1623 end = ((void *)-1);
1624 size = end - buf;
1627 while (*fmt) {
1628 const char *old_fmt = fmt;
1629 int read = format_decode(fmt, &spec);
1631 fmt += read;
1633 switch (spec.type) {
1634 case FORMAT_TYPE_NONE: {
1635 int copy = read;
1636 if (str < end) {
1637 if (copy > end - str)
1638 copy = end - str;
1639 memcpy(str, old_fmt, copy);
1641 str += read;
1642 break;
1645 case FORMAT_TYPE_WIDTH:
1646 spec.field_width = get_arg(int);
1647 break;
1649 case FORMAT_TYPE_PRECISION:
1650 spec.precision = get_arg(int);
1651 break;
1653 case FORMAT_TYPE_CHAR: {
1654 char c;
1656 if (!(spec.flags & LEFT)) {
1657 while (--spec.field_width > 0) {
1658 if (str < end)
1659 *str = ' ';
1660 ++str;
1663 c = (unsigned char) get_arg(char);
1664 if (str < end)
1665 *str = c;
1666 ++str;
1667 while (--spec.field_width > 0) {
1668 if (str < end)
1669 *str = ' ';
1670 ++str;
1672 break;
1675 case FORMAT_TYPE_STR: {
1676 const char *str_arg = args;
1677 args += strlen(str_arg) + 1;
1678 str = string(str, end, (char *)str_arg, spec);
1679 break;
1682 case FORMAT_TYPE_PTR:
1683 str = pointer(fmt+1, str, end, get_arg(void *), spec);
1684 while (isalnum(*fmt))
1685 fmt++;
1686 break;
1688 case FORMAT_TYPE_PERCENT_CHAR:
1689 case FORMAT_TYPE_INVALID:
1690 if (str < end)
1691 *str = '%';
1692 ++str;
1693 break;
1695 case FORMAT_TYPE_NRCHARS:
1696 /* skip */
1697 break;
1699 default: {
1700 unsigned long long num;
1702 switch (spec.type) {
1704 case FORMAT_TYPE_LONG_LONG:
1705 num = get_arg(long long);
1706 break;
1707 case FORMAT_TYPE_ULONG:
1708 case FORMAT_TYPE_LONG:
1709 num = get_arg(unsigned long);
1710 break;
1711 case FORMAT_TYPE_SIZE_T:
1712 num = get_arg(size_t);
1713 break;
1714 case FORMAT_TYPE_PTRDIFF:
1715 num = get_arg(ptrdiff_t);
1716 break;
1717 case FORMAT_TYPE_UBYTE:
1718 num = get_arg(unsigned char);
1719 break;
1720 case FORMAT_TYPE_BYTE:
1721 num = get_arg(signed char);
1722 break;
1723 case FORMAT_TYPE_USHORT:
1724 num = get_arg(unsigned short);
1725 break;
1726 case FORMAT_TYPE_SHORT:
1727 num = get_arg(short);
1728 break;
1729 case FORMAT_TYPE_UINT:
1730 num = get_arg(unsigned int);
1731 break;
1732 default:
1733 num = get_arg(int);
1736 str = number(str, end, num, spec);
1737 } /* default: */
1738 } /* switch(spec.type) */
1739 } /* while(*fmt) */
1741 if (size > 0) {
1742 if (str < end)
1743 *str = '\0';
1744 else
1745 end[-1] = '\0';
1748 #undef get_arg
1750 /* the trailing null byte doesn't count towards the total */
1751 return str - buf;
1753 EXPORT_SYMBOL_GPL(bstr_printf);
1756 * bprintf - Parse a format string and place args' binary value in a buffer
1757 * @bin_buf: The buffer to place args' binary value
1758 * @size: The size of the buffer(by words(32bits), not characters)
1759 * @fmt: The format string to use
1760 * @...: Arguments for the format string
1762 * The function returns the number of words(u32) written
1763 * into @bin_buf.
1765 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1767 va_list args;
1768 int ret;
1770 va_start(args, fmt);
1771 ret = vbin_printf(bin_buf, size, fmt, args);
1772 va_end(args);
1774 return ret;
1776 EXPORT_SYMBOL_GPL(bprintf);
1778 #endif /* CONFIG_BINARY_PRINTF */
1781 * vsscanf - Unformat a buffer into a list of arguments
1782 * @buf: input buffer
1783 * @fmt: format of buffer
1784 * @args: arguments
1786 int vsscanf(const char *buf, const char *fmt, va_list args)
1788 const char *str = buf;
1789 char *next;
1790 char digit;
1791 int num = 0;
1792 u8 qualifier;
1793 u8 base;
1794 s16 field_width;
1795 bool is_sign;
1797 while (*fmt && *str) {
1798 /* skip any white space in format */
1799 /* white space in format matchs any amount of
1800 * white space, including none, in the input.
1802 if (isspace(*fmt)) {
1803 fmt = skip_spaces(++fmt);
1804 str = skip_spaces(str);
1807 /* anything that is not a conversion must match exactly */
1808 if (*fmt != '%' && *fmt) {
1809 if (*fmt++ != *str++)
1810 break;
1811 continue;
1814 if (!*fmt)
1815 break;
1816 ++fmt;
1818 /* skip this conversion.
1819 * advance both strings to next white space
1821 if (*fmt == '*') {
1822 while (!isspace(*fmt) && *fmt != '%' && *fmt)
1823 fmt++;
1824 while (!isspace(*str) && *str)
1825 str++;
1826 continue;
1829 /* get field width */
1830 field_width = -1;
1831 if (isdigit(*fmt))
1832 field_width = skip_atoi(&fmt);
1834 /* get conversion qualifier */
1835 qualifier = -1;
1836 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1837 _tolower(*fmt) == 'z') {
1838 qualifier = *fmt++;
1839 if (unlikely(qualifier == *fmt)) {
1840 if (qualifier == 'h') {
1841 qualifier = 'H';
1842 fmt++;
1843 } else if (qualifier == 'l') {
1844 qualifier = 'L';
1845 fmt++;
1850 if (!*fmt || !*str)
1851 break;
1853 base = 10;
1854 is_sign = 0;
1856 switch (*fmt++) {
1857 case 'c':
1859 char *s = (char *)va_arg(args, char*);
1860 if (field_width == -1)
1861 field_width = 1;
1862 do {
1863 *s++ = *str++;
1864 } while (--field_width > 0 && *str);
1865 num++;
1867 continue;
1868 case 's':
1870 char *s = (char *)va_arg(args, char *);
1871 if (field_width == -1)
1872 field_width = SHRT_MAX;
1873 /* first, skip leading white space in buffer */
1874 str = skip_spaces(str);
1876 /* now copy until next white space */
1877 while (*str && !isspace(*str) && field_width--)
1878 *s++ = *str++;
1879 *s = '\0';
1880 num++;
1882 continue;
1883 case 'n':
1884 /* return number of characters read so far */
1886 int *i = (int *)va_arg(args, int*);
1887 *i = str - buf;
1889 continue;
1890 case 'o':
1891 base = 8;
1892 break;
1893 case 'x':
1894 case 'X':
1895 base = 16;
1896 break;
1897 case 'i':
1898 base = 0;
1899 case 'd':
1900 is_sign = 1;
1901 case 'u':
1902 break;
1903 case '%':
1904 /* looking for '%' in str */
1905 if (*str++ != '%')
1906 return num;
1907 continue;
1908 default:
1909 /* invalid format; stop here */
1910 return num;
1913 /* have some sort of integer conversion.
1914 * first, skip white space in buffer.
1916 str = skip_spaces(str);
1918 digit = *str;
1919 if (is_sign && digit == '-')
1920 digit = *(str + 1);
1922 if (!digit
1923 || (base == 16 && !isxdigit(digit))
1924 || (base == 10 && !isdigit(digit))
1925 || (base == 8 && (!isdigit(digit) || digit > '7'))
1926 || (base == 0 && !isdigit(digit)))
1927 break;
1929 switch (qualifier) {
1930 case 'H': /* that's 'hh' in format */
1931 if (is_sign) {
1932 signed char *s = (signed char *)va_arg(args, signed char *);
1933 *s = (signed char)simple_strtol(str, &next, base);
1934 } else {
1935 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1936 *s = (unsigned char)simple_strtoul(str, &next, base);
1938 break;
1939 case 'h':
1940 if (is_sign) {
1941 short *s = (short *)va_arg(args, short *);
1942 *s = (short)simple_strtol(str, &next, base);
1943 } else {
1944 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
1945 *s = (unsigned short)simple_strtoul(str, &next, base);
1947 break;
1948 case 'l':
1949 if (is_sign) {
1950 long *l = (long *)va_arg(args, long *);
1951 *l = simple_strtol(str, &next, base);
1952 } else {
1953 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
1954 *l = simple_strtoul(str, &next, base);
1956 break;
1957 case 'L':
1958 if (is_sign) {
1959 long long *l = (long long *)va_arg(args, long long *);
1960 *l = simple_strtoll(str, &next, base);
1961 } else {
1962 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
1963 *l = simple_strtoull(str, &next, base);
1965 break;
1966 case 'Z':
1967 case 'z':
1969 size_t *s = (size_t *)va_arg(args, size_t *);
1970 *s = (size_t)simple_strtoul(str, &next, base);
1972 break;
1973 default:
1974 if (is_sign) {
1975 int *i = (int *)va_arg(args, int *);
1976 *i = (int)simple_strtol(str, &next, base);
1977 } else {
1978 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
1979 *i = (unsigned int)simple_strtoul(str, &next, base);
1981 break;
1983 num++;
1985 if (!next)
1986 break;
1987 str = next;
1991 * Now we've come all the way through so either the input string or the
1992 * format ended. In the former case, there can be a %n at the current
1993 * position in the format that needs to be filled.
1995 if (*fmt == '%' && *(fmt + 1) == 'n') {
1996 int *p = (int *)va_arg(args, int *);
1997 *p = str - buf;
2000 return num;
2002 EXPORT_SYMBOL(vsscanf);
2005 * sscanf - Unformat a buffer into a list of arguments
2006 * @buf: input buffer
2007 * @fmt: formatting of buffer
2008 * @...: resulting arguments
2010 int sscanf(const char *buf, const char *fmt, ...)
2012 va_list args;
2013 int i;
2015 va_start(args, fmt);
2016 i = vsscanf(buf, fmt, args);
2017 va_end(args);
2019 return i;
2021 EXPORT_SYMBOL(sscanf);