1 /*
2 * linux/lib/vsprintf.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8 /*
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
10 */
11
12 /*
13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
14 * - changed to provide snprintf and vsnprintf functions
15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
16 * - scnprintf and vscnprintf
17 */
18
19 #include <stdarg.h>
20 #include <linux/module.h>
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/ctype.h>
24 #include <linux/kernel.h>
25 #include <linux/kallsyms.h>
26 #include <linux/uaccess.h>
27 #include <linux/ioport.h>
28 #include <net/addrconf.h>
29
30 #include <asm/page.h> /* for PAGE_SIZE */
31 #include <asm/div64.h>
32 #include <asm/sections.h> /* for dereference_function_descriptor() */
33
34 /* Works only for digits and letters, but small and fast */
35 #define TOLOWER(x) ((x) | 0x20)
36
simple_guess_base(const char * cp)37 static unsigned int simple_guess_base(const char *cp)
38 {
39 if (cp[0] == '0') {
40 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
41 return 16;
42 else
43 return 8;
44 } else {
45 return 10;
46 }
47 }
48
49 /**
50 * simple_strtoull - convert a string to an unsigned long long
51 * @cp: The start of the string
52 * @endp: A pointer to the end of the parsed string will be placed here
53 * @base: The number base to use
54 */
simple_strtoull(const char * cp,char ** endp,unsigned int base)55 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
56 {
57 unsigned long long result = 0;
58
59 if (!base)
60 base = simple_guess_base(cp);
61
62 if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
63 cp += 2;
64
65 while (isxdigit(*cp)) {
66 unsigned int value;
67
68 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
69 if (value >= base)
70 break;
71 result = result * base + value;
72 cp++;
73 }
74 if (endp)
75 *endp = (char *)cp;
76
77 return result;
78 }
79 EXPORT_SYMBOL(simple_strtoull);
80
81 /**
82 * simple_strtoul - convert a string to an unsigned long
83 * @cp: The start of the string
84 * @endp: A pointer to the end of the parsed string will be placed here
85 * @base: The number base to use
86 */
simple_strtoul(const char * cp,char ** endp,unsigned int base)87 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
88 {
89 return simple_strtoull(cp, endp, base);
90 }
91 EXPORT_SYMBOL(simple_strtoul);
92
93 /**
94 * simple_strtol - convert a string to a signed long
95 * @cp: The start of the string
96 * @endp: A pointer to the end of the parsed string will be placed here
97 * @base: The number base to use
98 */
simple_strtol(const char * cp,char ** endp,unsigned int base)99 long simple_strtol(const char *cp, char **endp, unsigned int base)
100 {
101 if (*cp == '-')
102 return -simple_strtoul(cp + 1, endp, base);
103
104 return simple_strtoul(cp, endp, base);
105 }
106 EXPORT_SYMBOL(simple_strtol);
107
108 /**
109 * simple_strtoll - convert a string to a signed long long
110 * @cp: The start of the string
111 * @endp: A pointer to the end of the parsed string will be placed here
112 * @base: The number base to use
113 */
simple_strtoll(const char * cp,char ** endp,unsigned int base)114 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
115 {
116 if (*cp == '-')
117 return -simple_strtoull(cp + 1, endp, base);
118
119 return simple_strtoull(cp, endp, base);
120 }
121 EXPORT_SYMBOL(simple_strtoll);
122
123 static noinline_for_stack
skip_atoi(const char ** s)124 int skip_atoi(const char **s)
125 {
126 int i = 0;
127
128 while (isdigit(**s))
129 i = i*10 + *((*s)++) - '0';
130
131 return i;
132 }
133
134 /* Decimal conversion is by far the most typical, and is used
135 * for /proc and /sys data. This directly impacts e.g. top performance
136 * with many processes running. We optimize it for speed
137 * using code from
138 * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
139 * (with permission from the author, Douglas W. Jones). */
140
141 /* Formats correctly any integer in [0,99999].
142 * Outputs from one to five digits depending on input.
143 * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
144 static noinline_for_stack
put_dec_trunc(char * buf,unsigned q)145 char *put_dec_trunc(char *buf, unsigned q)
146 {
147 unsigned d3, d2, d1, d0;
148 d1 = (q>>4) & 0xf;
149 d2 = (q>>8) & 0xf;
150 d3 = (q>>12);
151
152 d0 = 6*(d3 + d2 + d1) + (q & 0xf);
153 q = (d0 * 0xcd) >> 11;
154 d0 = d0 - 10*q;
155 *buf++ = d0 + '0'; /* least significant digit */
156 d1 = q + 9*d3 + 5*d2 + d1;
157 if (d1 != 0) {
158 q = (d1 * 0xcd) >> 11;
159 d1 = d1 - 10*q;
160 *buf++ = d1 + '0'; /* next digit */
161
162 d2 = q + 2*d2;
163 if ((d2 != 0) || (d3 != 0)) {
164 q = (d2 * 0xd) >> 7;
165 d2 = d2 - 10*q;
166 *buf++ = d2 + '0'; /* next digit */
167
168 d3 = q + 4*d3;
169 if (d3 != 0) {
170 q = (d3 * 0xcd) >> 11;
171 d3 = d3 - 10*q;
172 *buf++ = d3 + '0'; /* next digit */
173 if (q != 0)
174 *buf++ = q + '0'; /* most sign. digit */
175 }
176 }
177 }
178
179 return buf;
180 }
181 /* Same with if's removed. Always emits five digits */
182 static noinline_for_stack
put_dec_full(char * buf,unsigned q)183 char *put_dec_full(char *buf, unsigned q)
184 {
185 /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
186 /* but anyway, gcc produces better code with full-sized ints */
187 unsigned d3, d2, d1, d0;
188 d1 = (q>>4) & 0xf;
189 d2 = (q>>8) & 0xf;
190 d3 = (q>>12);
191
192 /*
193 * Possible ways to approx. divide by 10
194 * gcc -O2 replaces multiply with shifts and adds
195 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
196 * (x * 0x67) >> 10: 1100111
197 * (x * 0x34) >> 9: 110100 - same
198 * (x * 0x1a) >> 8: 11010 - same
199 * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
200 */
201 d0 = 6*(d3 + d2 + d1) + (q & 0xf);
202 q = (d0 * 0xcd) >> 11;
203 d0 = d0 - 10*q;
204 *buf++ = d0 + '0';
205 d1 = q + 9*d3 + 5*d2 + d1;
206 q = (d1 * 0xcd) >> 11;
207 d1 = d1 - 10*q;
208 *buf++ = d1 + '0';
209
210 d2 = q + 2*d2;
211 q = (d2 * 0xd) >> 7;
212 d2 = d2 - 10*q;
213 *buf++ = d2 + '0';
214
215 d3 = q + 4*d3;
216 q = (d3 * 0xcd) >> 11; /* - shorter code */
217 /* q = (d3 * 0x67) >> 10; - would also work */
218 d3 = d3 - 10*q;
219 *buf++ = d3 + '0';
220 *buf++ = q + '0';
221
222 return buf;
223 }
224 /* No inlining helps gcc to use registers better */
225 static noinline_for_stack
put_dec(char * buf,unsigned long long num)226 char *put_dec(char *buf, unsigned long long num)
227 {
228 while (1) {
229 unsigned rem;
230 if (num < 100000)
231 return put_dec_trunc(buf, num);
232 rem = do_div(num, 100000);
233 buf = put_dec_full(buf, rem);
234 }
235 }
236
237 #define ZEROPAD 1 /* pad with zero */
238 #define SIGN 2 /* unsigned/signed long */
239 #define PLUS 4 /* show plus */
240 #define SPACE 8 /* space if plus */
241 #define LEFT 16 /* left justified */
242 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
243 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
244
245 enum format_type {
246 FORMAT_TYPE_NONE, /* Just a string part */
247 FORMAT_TYPE_WIDTH,
248 FORMAT_TYPE_PRECISION,
249 FORMAT_TYPE_CHAR,
250 FORMAT_TYPE_STR,
251 FORMAT_TYPE_PTR,
252 FORMAT_TYPE_PERCENT_CHAR,
253 FORMAT_TYPE_INVALID,
254 FORMAT_TYPE_LONG_LONG,
255 FORMAT_TYPE_ULONG,
256 FORMAT_TYPE_LONG,
257 FORMAT_TYPE_UBYTE,
258 FORMAT_TYPE_BYTE,
259 FORMAT_TYPE_USHORT,
260 FORMAT_TYPE_SHORT,
261 FORMAT_TYPE_UINT,
262 FORMAT_TYPE_INT,
263 FORMAT_TYPE_NRCHARS,
264 FORMAT_TYPE_SIZE_T,
265 FORMAT_TYPE_PTRDIFF
266 };
267
268 struct printf_spec {
269 u8 type; /* format_type enum */
270 u8 flags; /* flags to number() */
271 u8 base; /* number base, 8, 10 or 16 only */
272 u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */
273 s16 field_width; /* width of output field */
274 s16 precision; /* # of digits/chars */
275 };
276
277 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)278 char *number(char *buf, char *end, unsigned long long num,
279 struct printf_spec spec)
280 {
281 /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
282 static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
283
284 char tmp[66];
285 char sign;
286 char locase;
287 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
288 int i;
289
290 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
291 * produces same digits or (maybe lowercased) letters */
292 locase = (spec.flags & SMALL);
293 if (spec.flags & LEFT)
294 spec.flags &= ~ZEROPAD;
295 sign = 0;
296 if (spec.flags & SIGN) {
297 if ((signed long long)num < 0) {
298 sign = '-';
299 num = -(signed long long)num;
300 spec.field_width--;
301 } else if (spec.flags & PLUS) {
302 sign = '+';
303 spec.field_width--;
304 } else if (spec.flags & SPACE) {
305 sign = ' ';
306 spec.field_width--;
307 }
308 }
309 if (need_pfx) {
310 spec.field_width--;
311 if (spec.base == 16)
312 spec.field_width--;
313 }
314
315 /* generate full string in tmp[], in reverse order */
316 i = 0;
317 if (num == 0)
318 tmp[i++] = '0';
319 /* Generic code, for any base:
320 else do {
321 tmp[i++] = (digits[do_div(num,base)] | locase);
322 } while (num != 0);
323 */
324 else if (spec.base != 10) { /* 8 or 16 */
325 int mask = spec.base - 1;
326 int shift = 3;
327
328 if (spec.base == 16)
329 shift = 4;
330 do {
331 tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
332 num >>= shift;
333 } while (num);
334 } else { /* base 10 */
335 i = put_dec(tmp, num) - tmp;
336 }
337
338 /* printing 100 using %2d gives "100", not "00" */
339 if (i > spec.precision)
340 spec.precision = i;
341 /* leading space padding */
342 spec.field_width -= spec.precision;
343 if (!(spec.flags & (ZEROPAD+LEFT))) {
344 while (--spec.field_width >= 0) {
345 if (buf < end)
346 *buf = ' ';
347 ++buf;
348 }
349 }
350 /* sign */
351 if (sign) {
352 if (buf < end)
353 *buf = sign;
354 ++buf;
355 }
356 /* "0x" / "0" prefix */
357 if (need_pfx) {
358 if (buf < end)
359 *buf = '0';
360 ++buf;
361 if (spec.base == 16) {
362 if (buf < end)
363 *buf = ('X' | locase);
364 ++buf;
365 }
366 }
367 /* zero or space padding */
368 if (!(spec.flags & LEFT)) {
369 char c = (spec.flags & ZEROPAD) ? '0' : ' ';
370 while (--spec.field_width >= 0) {
371 if (buf < end)
372 *buf = c;
373 ++buf;
374 }
375 }
376 /* hmm even more zero padding? */
377 while (i <= --spec.precision) {
378 if (buf < end)
379 *buf = '0';
380 ++buf;
381 }
382 /* actual digits of result */
383 while (--i >= 0) {
384 if (buf < end)
385 *buf = tmp[i];
386 ++buf;
387 }
388 /* trailing space padding */
389 while (--spec.field_width >= 0) {
390 if (buf < end)
391 *buf = ' ';
392 ++buf;
393 }
394
395 return buf;
396 }
397
398 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)399 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
400 {
401 int len, i;
402
403 if ((unsigned long)s < PAGE_SIZE)
404 s = "(null)";
405
406 len = strnlen(s, spec.precision);
407
408 if (!(spec.flags & LEFT)) {
409 while (len < spec.field_width--) {
410 if (buf < end)
411 *buf = ' ';
412 ++buf;
413 }
414 }
415 for (i = 0; i < len; ++i) {
416 if (buf < end)
417 *buf = *s;
418 ++buf; ++s;
419 }
420 while (len < spec.field_width--) {
421 if (buf < end)
422 *buf = ' ';
423 ++buf;
424 }
425
426 return buf;
427 }
428
429 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,char ext)430 char *symbol_string(char *buf, char *end, void *ptr,
431 struct printf_spec spec, char ext)
432 {
433 unsigned long value = (unsigned long) ptr;
434 #ifdef CONFIG_KALLSYMS
435 char sym[KSYM_SYMBOL_LEN];
436 if (ext == 'B')
437 sprint_backtrace(sym, value);
438 else if (ext != 'f' && ext != 's')
439 sprint_symbol(sym, value);
440 else
441 kallsyms_lookup(value, NULL, NULL, NULL, sym);
442
443 return string(buf, end, sym, spec);
444 #else
445 spec.field_width = 2 * sizeof(void *);
446 spec.flags |= SPECIAL | SMALL | ZEROPAD;
447 spec.base = 16;
448
449 return number(buf, end, value, spec);
450 #endif
451 }
452
453 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)454 char *resource_string(char *buf, char *end, struct resource *res,
455 struct printf_spec spec, const char *fmt)
456 {
457 #ifndef IO_RSRC_PRINTK_SIZE
458 #define IO_RSRC_PRINTK_SIZE 6
459 #endif
460
461 #ifndef MEM_RSRC_PRINTK_SIZE
462 #define MEM_RSRC_PRINTK_SIZE 10
463 #endif
464 static const struct printf_spec io_spec = {
465 .base = 16,
466 .field_width = IO_RSRC_PRINTK_SIZE,
467 .precision = -1,
468 .flags = SPECIAL | SMALL | ZEROPAD,
469 };
470 static const struct printf_spec mem_spec = {
471 .base = 16,
472 .field_width = MEM_RSRC_PRINTK_SIZE,
473 .precision = -1,
474 .flags = SPECIAL | SMALL | ZEROPAD,
475 };
476 static const struct printf_spec bus_spec = {
477 .base = 16,
478 .field_width = 2,
479 .precision = -1,
480 .flags = SMALL | ZEROPAD,
481 };
482 static const struct printf_spec dec_spec = {
483 .base = 10,
484 .precision = -1,
485 .flags = 0,
486 };
487 static const struct printf_spec str_spec = {
488 .field_width = -1,
489 .precision = 10,
490 .flags = LEFT,
491 };
492 static const struct printf_spec flag_spec = {
493 .base = 16,
494 .precision = -1,
495 .flags = SPECIAL | SMALL,
496 };
497
498 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
499 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
500 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
501 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
502 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
503 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
504 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
505 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
506
507 char *p = sym, *pend = sym + sizeof(sym);
508 int decode = (fmt[0] == 'R') ? 1 : 0;
509 const struct printf_spec *specp;
510
511 *p++ = '[';
512 if (res->flags & IORESOURCE_IO) {
513 p = string(p, pend, "io ", str_spec);
514 specp = &io_spec;
515 } else if (res->flags & IORESOURCE_MEM) {
516 p = string(p, pend, "mem ", str_spec);
517 specp = &mem_spec;
518 } else if (res->flags & IORESOURCE_IRQ) {
519 p = string(p, pend, "irq ", str_spec);
520 specp = &dec_spec;
521 } else if (res->flags & IORESOURCE_DMA) {
522 p = string(p, pend, "dma ", str_spec);
523 specp = &dec_spec;
524 } else if (res->flags & IORESOURCE_BUS) {
525 p = string(p, pend, "bus ", str_spec);
526 specp = &bus_spec;
527 } else {
528 p = string(p, pend, "??? ", str_spec);
529 specp = &mem_spec;
530 decode = 0;
531 }
532 p = number(p, pend, res->start, *specp);
533 if (res->start != res->end) {
534 *p++ = '-';
535 p = number(p, pend, res->end, *specp);
536 }
537 if (decode) {
538 if (res->flags & IORESOURCE_MEM_64)
539 p = string(p, pend, " 64bit", str_spec);
540 if (res->flags & IORESOURCE_PREFETCH)
541 p = string(p, pend, " pref", str_spec);
542 if (res->flags & IORESOURCE_WINDOW)
543 p = string(p, pend, " window", str_spec);
544 if (res->flags & IORESOURCE_DISABLED)
545 p = string(p, pend, " disabled", str_spec);
546 } else {
547 p = string(p, pend, " flags ", str_spec);
548 p = number(p, pend, res->flags, flag_spec);
549 }
550 *p++ = ']';
551 *p = '\0';
552
553 return string(buf, end, sym, spec);
554 }
555
556 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)557 char *mac_address_string(char *buf, char *end, u8 *addr,
558 struct printf_spec spec, const char *fmt)
559 {
560 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
561 char *p = mac_addr;
562 int i;
563 char separator;
564
565 if (fmt[1] == 'F') { /* FDDI canonical format */
566 separator = '-';
567 } else {
568 separator = ':';
569 }
570
571 for (i = 0; i < 6; i++) {
572 p = pack_hex_byte(p, addr[i]);
573 if (fmt[0] == 'M' && i != 5)
574 *p++ = separator;
575 }
576 *p = '\0';
577
578 return string(buf, end, mac_addr, spec);
579 }
580
581 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)582 char *ip4_string(char *p, const u8 *addr, const char *fmt)
583 {
584 int i;
585 bool leading_zeros = (fmt[0] == 'i');
586 int index;
587 int step;
588
589 switch (fmt[2]) {
590 case 'h':
591 #ifdef __BIG_ENDIAN
592 index = 0;
593 step = 1;
594 #else
595 index = 3;
596 step = -1;
597 #endif
598 break;
599 case 'l':
600 index = 3;
601 step = -1;
602 break;
603 case 'n':
604 case 'b':
605 default:
606 index = 0;
607 step = 1;
608 break;
609 }
610 for (i = 0; i < 4; i++) {
611 char temp[3]; /* hold each IP quad in reverse order */
612 int digits = put_dec_trunc(temp, addr[index]) - temp;
613 if (leading_zeros) {
614 if (digits < 3)
615 *p++ = '0';
616 if (digits < 2)
617 *p++ = '0';
618 }
619 /* reverse the digits in the quad */
620 while (digits--)
621 *p++ = temp[digits];
622 if (i < 3)
623 *p++ = '.';
624 index += step;
625 }
626 *p = '\0';
627
628 return p;
629 }
630
631 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)632 char *ip6_compressed_string(char *p, const char *addr)
633 {
634 int i, j, range;
635 unsigned char zerolength[8];
636 int longest = 1;
637 int colonpos = -1;
638 u16 word;
639 u8 hi, lo;
640 bool needcolon = false;
641 bool useIPv4;
642 struct in6_addr in6;
643
644 memcpy(&in6, addr, sizeof(struct in6_addr));
645
646 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
647
648 memset(zerolength, 0, sizeof(zerolength));
649
650 if (useIPv4)
651 range = 6;
652 else
653 range = 8;
654
655 /* find position of longest 0 run */
656 for (i = 0; i < range; i++) {
657 for (j = i; j < range; j++) {
658 if (in6.s6_addr16[j] != 0)
659 break;
660 zerolength[i]++;
661 }
662 }
663 for (i = 0; i < range; i++) {
664 if (zerolength[i] > longest) {
665 longest = zerolength[i];
666 colonpos = i;
667 }
668 }
669
670 /* emit address */
671 for (i = 0; i < range; i++) {
672 if (i == colonpos) {
673 if (needcolon || i == 0)
674 *p++ = ':';
675 *p++ = ':';
676 needcolon = false;
677 i += longest - 1;
678 continue;
679 }
680 if (needcolon) {
681 *p++ = ':';
682 needcolon = false;
683 }
684 /* hex u16 without leading 0s */
685 word = ntohs(in6.s6_addr16[i]);
686 hi = word >> 8;
687 lo = word & 0xff;
688 if (hi) {
689 if (hi > 0x0f)
690 p = pack_hex_byte(p, hi);
691 else
692 *p++ = hex_asc_lo(hi);
693 p = pack_hex_byte(p, lo);
694 }
695 else if (lo > 0x0f)
696 p = pack_hex_byte(p, lo);
697 else
698 *p++ = hex_asc_lo(lo);
699 needcolon = true;
700 }
701
702 if (useIPv4) {
703 if (needcolon)
704 *p++ = ':';
705 p = ip4_string(p, &in6.s6_addr[12], "I4");
706 }
707 *p = '\0';
708
709 return p;
710 }
711
712 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)713 char *ip6_string(char *p, const char *addr, const char *fmt)
714 {
715 int i;
716
717 for (i = 0; i < 8; i++) {
718 p = pack_hex_byte(p, *addr++);
719 p = pack_hex_byte(p, *addr++);
720 if (fmt[0] == 'I' && i != 7)
721 *p++ = ':';
722 }
723 *p = '\0';
724
725 return p;
726 }
727
728 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)729 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
730 struct printf_spec spec, const char *fmt)
731 {
732 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
733
734 if (fmt[0] == 'I' && fmt[2] == 'c')
735 ip6_compressed_string(ip6_addr, addr);
736 else
737 ip6_string(ip6_addr, addr, fmt);
738
739 return string(buf, end, ip6_addr, spec);
740 }
741
742 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)743 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
744 struct printf_spec spec, const char *fmt)
745 {
746 char ip4_addr[sizeof("255.255.255.255")];
747
748 ip4_string(ip4_addr, addr, fmt);
749
750 return string(buf, end, ip4_addr, spec);
751 }
752
753 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)754 char *uuid_string(char *buf, char *end, const u8 *addr,
755 struct printf_spec spec, const char *fmt)
756 {
757 char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
758 char *p = uuid;
759 int i;
760 static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
761 static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
762 const u8 *index = be;
763 bool uc = false;
764
765 switch (*(++fmt)) {
766 case 'L':
767 uc = true; /* fall-through */
768 case 'l':
769 index = le;
770 break;
771 case 'B':
772 uc = true;
773 break;
774 }
775
776 for (i = 0; i < 16; i++) {
777 p = pack_hex_byte(p, addr[index[i]]);
778 switch (i) {
779 case 3:
780 case 5:
781 case 7:
782 case 9:
783 *p++ = '-';
784 break;
785 }
786 }
787
788 *p = 0;
789
790 if (uc) {
791 p = uuid;
792 do {
793 *p = toupper(*p);
794 } while (*(++p));
795 }
796
797 return string(buf, end, uuid, spec);
798 }
799
800 int kptr_restrict __read_mostly;
801
802 /*
803 * Show a '%p' thing. A kernel extension is that the '%p' is followed
804 * by an extra set of alphanumeric characters that are extended format
805 * specifiers.
806 *
807 * Right now we handle:
808 *
809 * - 'F' For symbolic function descriptor pointers with offset
810 * - 'f' For simple symbolic function names without offset
811 * - 'S' For symbolic direct pointers with offset
812 * - 's' For symbolic direct pointers without offset
813 * - 'B' For backtraced symbolic direct pointers with offset
814 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
815 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
816 * - 'M' For a 6-byte MAC address, it prints the address in the
817 * usual colon-separated hex notation
818 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
819 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
820 * with a dash-separated hex notation
821 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
822 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
823 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
824 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
825 * IPv6 omits the colons (01020304...0f)
826 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
827 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
828 * - 'I6c' for IPv6 addresses printed as specified by
829 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
830 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
831 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
832 * Options for %pU are:
833 * b big endian lower case hex (default)
834 * B big endian UPPER case hex
835 * l little endian lower case hex
836 * L little endian UPPER case hex
837 * big endian output byte order is:
838 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
839 * little endian output byte order is:
840 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
841 * - 'V' For a struct va_format which contains a format string * and va_list *,
842 * call vsnprintf(->format, *->va_list).
843 * Implements a "recursive vsnprintf".
844 * Do not use this feature without some mechanism to verify the
845 * correctness of the format string and va_list arguments.
846 * - 'K' For a kernel pointer that should be hidden from unprivileged users
847 *
848 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
849 * function pointers are really function descriptors, which contain a
850 * pointer to the real address.
851 */
852 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)853 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
854 struct printf_spec spec)
855 {
856 if (!ptr && *fmt != 'K') {
857 /*
858 * Print (null) with the same width as a pointer so it makes
859 * tabular output look nice.
860 */
861 if (spec.field_width == -1)
862 spec.field_width = 2 * sizeof(void *);
863 return string(buf, end, "(null)", spec);
864 }
865
866 switch (*fmt) {
867 case 'F':
868 case 'f':
869 ptr = dereference_function_descriptor(ptr);
870 /* Fallthrough */
871 case 'S':
872 case 's':
873 case 'B':
874 return symbol_string(buf, end, ptr, spec, *fmt);
875 case 'R':
876 case 'r':
877 return resource_string(buf, end, ptr, spec, fmt);
878 case 'M': /* Colon separated: 00:01:02:03:04:05 */
879 case 'm': /* Contiguous: 000102030405 */
880 /* [mM]F (FDDI, bit reversed) */
881 return mac_address_string(buf, end, ptr, spec, fmt);
882 case 'I': /* Formatted IP supported
883 * 4: 1.2.3.4
884 * 6: 0001:0203:...:0708
885 * 6c: 1::708 or 1::1.2.3.4
886 */
887 case 'i': /* Contiguous:
888 * 4: 001.002.003.004
889 * 6: 000102...0f
890 */
891 switch (fmt[1]) {
892 case '6':
893 return ip6_addr_string(buf, end, ptr, spec, fmt);
894 case '4':
895 return ip4_addr_string(buf, end, ptr, spec, fmt);
896 }
897 break;
898 case 'U':
899 return uuid_string(buf, end, ptr, spec, fmt);
900 case 'V':
901 return buf + vsnprintf(buf, end - buf,
902 ((struct va_format *)ptr)->fmt,
903 *(((struct va_format *)ptr)->va));
904 case 'K':
905 /*
906 * %pK cannot be used in IRQ context because its test
907 * for CAP_SYSLOG would be meaningless.
908 */
909 if (in_irq() || in_serving_softirq() || in_nmi()) {
910 if (spec.field_width == -1)
911 spec.field_width = 2 * sizeof(void *);
912 return string(buf, end, "pK-error", spec);
913 }
914 if (!((kptr_restrict == 0) ||
915 (kptr_restrict == 1 &&
916 has_capability_noaudit(current, CAP_SYSLOG))))
917 ptr = NULL;
918 break;
919 }
920 spec.flags |= SMALL;
921 if (spec.field_width == -1) {
922 spec.field_width = 2 * sizeof(void *);
923 spec.flags |= ZEROPAD;
924 }
925 spec.base = 16;
926
927 return number(buf, end, (unsigned long) ptr, spec);
928 }
929
930 /*
931 * Helper function to decode printf style format.
932 * Each call decode a token from the format and return the
933 * number of characters read (or likely the delta where it wants
934 * to go on the next call).
935 * The decoded token is returned through the parameters
936 *
937 * 'h', 'l', or 'L' for integer fields
938 * 'z' support added 23/7/1999 S.H.
939 * 'z' changed to 'Z' --davidm 1/25/99
940 * 't' added for ptrdiff_t
941 *
942 * @fmt: the format string
943 * @type of the token returned
944 * @flags: various flags such as +, -, # tokens..
945 * @field_width: overwritten width
946 * @base: base of the number (octal, hex, ...)
947 * @precision: precision of a number
948 * @qualifier: qualifier of a number (long, size_t, ...)
949 */
950 static noinline_for_stack
format_decode(const char * fmt,struct printf_spec * spec)951 int format_decode(const char *fmt, struct printf_spec *spec)
952 {
953 const char *start = fmt;
954
955 /* we finished early by reading the field width */
956 if (spec->type == FORMAT_TYPE_WIDTH) {
957 if (spec->field_width < 0) {
958 spec->field_width = -spec->field_width;
959 spec->flags |= LEFT;
960 }
961 spec->type = FORMAT_TYPE_NONE;
962 goto precision;
963 }
964
965 /* we finished early by reading the precision */
966 if (spec->type == FORMAT_TYPE_PRECISION) {
967 if (spec->precision < 0)
968 spec->precision = 0;
969
970 spec->type = FORMAT_TYPE_NONE;
971 goto qualifier;
972 }
973
974 /* By default */
975 spec->type = FORMAT_TYPE_NONE;
976
977 for (; *fmt ; ++fmt) {
978 if (*fmt == '%')
979 break;
980 }
981
982 /* Return the current non-format string */
983 if (fmt != start || !*fmt)
984 return fmt - start;
985
986 /* Process flags */
987 spec->flags = 0;
988
989 while (1) { /* this also skips first '%' */
990 bool found = true;
991
992 ++fmt;
993
994 switch (*fmt) {
995 case '-': spec->flags |= LEFT; break;
996 case '+': spec->flags |= PLUS; break;
997 case ' ': spec->flags |= SPACE; break;
998 case '#': spec->flags |= SPECIAL; break;
999 case '0': spec->flags |= ZEROPAD; break;
1000 default: found = false;
1001 }
1002
1003 if (!found)
1004 break;
1005 }
1006
1007 /* get field width */
1008 spec->field_width = -1;
1009
1010 if (isdigit(*fmt))
1011 spec->field_width = skip_atoi(&fmt);
1012 else if (*fmt == '*') {
1013 /* it's the next argument */
1014 spec->type = FORMAT_TYPE_WIDTH;
1015 return ++fmt - start;
1016 }
1017
1018 precision:
1019 /* get the precision */
1020 spec->precision = -1;
1021 if (*fmt == '.') {
1022 ++fmt;
1023 if (isdigit(*fmt)) {
1024 spec->precision = skip_atoi(&fmt);
1025 if (spec->precision < 0)
1026 spec->precision = 0;
1027 } else if (*fmt == '*') {
1028 /* it's the next argument */
1029 spec->type = FORMAT_TYPE_PRECISION;
1030 return ++fmt - start;
1031 }
1032 }
1033
1034 qualifier:
1035 /* get the conversion qualifier */
1036 spec->qualifier = -1;
1037 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1038 TOLOWER(*fmt) == 'z' || *fmt == 't') {
1039 spec->qualifier = *fmt++;
1040 if (unlikely(spec->qualifier == *fmt)) {
1041 if (spec->qualifier == 'l') {
1042 spec->qualifier = 'L';
1043 ++fmt;
1044 } else if (spec->qualifier == 'h') {
1045 spec->qualifier = 'H';
1046 ++fmt;
1047 }
1048 }
1049 }
1050
1051 /* default base */
1052 spec->base = 10;
1053 switch (*fmt) {
1054 case 'c':
1055 spec->type = FORMAT_TYPE_CHAR;
1056 return ++fmt - start;
1057
1058 case 's':
1059 spec->type = FORMAT_TYPE_STR;
1060 return ++fmt - start;
1061
1062 case 'p':
1063 spec->type = FORMAT_TYPE_PTR;
1064 return fmt - start;
1065 /* skip alnum */
1066
1067 case 'n':
1068 spec->type = FORMAT_TYPE_NRCHARS;
1069 return ++fmt - start;
1070
1071 case '%':
1072 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1073 return ++fmt - start;
1074
1075 /* integer number formats - set up the flags and "break" */
1076 case 'o':
1077 spec->base = 8;
1078 break;
1079
1080 case 'x':
1081 spec->flags |= SMALL;
1082
1083 case 'X':
1084 spec->base = 16;
1085 break;
1086
1087 case 'd':
1088 case 'i':
1089 spec->flags |= SIGN;
1090 case 'u':
1091 break;
1092
1093 default:
1094 spec->type = FORMAT_TYPE_INVALID;
1095 return fmt - start;
1096 }
1097
1098 if (spec->qualifier == 'L')
1099 spec->type = FORMAT_TYPE_LONG_LONG;
1100 else if (spec->qualifier == 'l') {
1101 if (spec->flags & SIGN)
1102 spec->type = FORMAT_TYPE_LONG;
1103 else
1104 spec->type = FORMAT_TYPE_ULONG;
1105 } else if (TOLOWER(spec->qualifier) == 'z') {
1106 spec->type = FORMAT_TYPE_SIZE_T;
1107 } else if (spec->qualifier == 't') {
1108 spec->type = FORMAT_TYPE_PTRDIFF;
1109 } else if (spec->qualifier == 'H') {
1110 if (spec->flags & SIGN)
1111 spec->type = FORMAT_TYPE_BYTE;
1112 else
1113 spec->type = FORMAT_TYPE_UBYTE;
1114 } else if (spec->qualifier == 'h') {
1115 if (spec->flags & SIGN)
1116 spec->type = FORMAT_TYPE_SHORT;
1117 else
1118 spec->type = FORMAT_TYPE_USHORT;
1119 } else {
1120 if (spec->flags & SIGN)
1121 spec->type = FORMAT_TYPE_INT;
1122 else
1123 spec->type = FORMAT_TYPE_UINT;
1124 }
1125
1126 return ++fmt - start;
1127 }
1128
1129 /**
1130 * vsnprintf - Format a string and place it in a buffer
1131 * @buf: The buffer to place the result into
1132 * @size: The size of the buffer, including the trailing null space
1133 * @fmt: The format string to use
1134 * @args: Arguments for the format string
1135 *
1136 * This function follows C99 vsnprintf, but has some extensions:
1137 * %pS output the name of a text symbol with offset
1138 * %ps output the name of a text symbol without offset
1139 * %pF output the name of a function pointer with its offset
1140 * %pf output the name of a function pointer without its offset
1141 * %pB output the name of a backtrace symbol with its offset
1142 * %pR output the address range in a struct resource with decoded flags
1143 * %pr output the address range in a struct resource with raw flags
1144 * %pM output a 6-byte MAC address with colons
1145 * %pm output a 6-byte MAC address without colons
1146 * %pI4 print an IPv4 address without leading zeros
1147 * %pi4 print an IPv4 address with leading zeros
1148 * %pI6 print an IPv6 address with colons
1149 * %pi6 print an IPv6 address without colons
1150 * %pI6c print an IPv6 address as specified by
1151 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
1152 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1153 * case.
1154 * %n is ignored
1155 *
1156 * The return value is the number of characters which would
1157 * be generated for the given input, excluding the trailing
1158 * '\0', as per ISO C99. If you want to have the exact
1159 * number of characters written into @buf as return value
1160 * (not including the trailing '\0'), use vscnprintf(). If the
1161 * return is greater than or equal to @size, the resulting
1162 * string is truncated.
1163 *
1164 * Call this function if you are already dealing with a va_list.
1165 * You probably want snprintf() instead.
1166 */
vsnprintf(char * buf,size_t size,const char * fmt,va_list args)1167 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1168 {
1169 unsigned long long num;
1170 char *str, *end;
1171 struct printf_spec spec = {0};
1172
1173 /* Reject out-of-range values early. Large positive sizes are
1174 used for unknown buffer sizes. */
1175 if (WARN_ON_ONCE((int) size < 0))
1176 return 0;
1177
1178 str = buf;
1179 end = buf + size;
1180
1181 /* Make sure end is always >= buf */
1182 if (end < buf) {
1183 end = ((void *)-1);
1184 size = end - buf;
1185 }
1186
1187 while (*fmt) {
1188 const char *old_fmt = fmt;
1189 int read = format_decode(fmt, &spec);
1190
1191 fmt += read;
1192
1193 switch (spec.type) {
1194 case FORMAT_TYPE_NONE: {
1195 int copy = read;
1196 if (str < end) {
1197 if (copy > end - str)
1198 copy = end - str;
1199 memcpy(str, old_fmt, copy);
1200 }
1201 str += read;
1202 break;
1203 }
1204
1205 case FORMAT_TYPE_WIDTH:
1206 spec.field_width = va_arg(args, int);
1207 break;
1208
1209 case FORMAT_TYPE_PRECISION:
1210 spec.precision = va_arg(args, int);
1211 break;
1212
1213 case FORMAT_TYPE_CHAR: {
1214 char c;
1215
1216 if (!(spec.flags & LEFT)) {
1217 while (--spec.field_width > 0) {
1218 if (str < end)
1219 *str = ' ';
1220 ++str;
1221
1222 }
1223 }
1224 c = (unsigned char) va_arg(args, int);
1225 if (str < end)
1226 *str = c;
1227 ++str;
1228 while (--spec.field_width > 0) {
1229 if (str < end)
1230 *str = ' ';
1231 ++str;
1232 }
1233 break;
1234 }
1235
1236 case FORMAT_TYPE_STR:
1237 str = string(str, end, va_arg(args, char *), spec);
1238 break;
1239
1240 case FORMAT_TYPE_PTR:
1241 str = pointer(fmt+1, str, end, va_arg(args, void *),
1242 spec);
1243 while (isalnum(*fmt))
1244 fmt++;
1245 break;
1246
1247 case FORMAT_TYPE_PERCENT_CHAR:
1248 if (str < end)
1249 *str = '%';
1250 ++str;
1251 break;
1252
1253 case FORMAT_TYPE_INVALID:
1254 if (str < end)
1255 *str = '%';
1256 ++str;
1257 break;
1258
1259 case FORMAT_TYPE_NRCHARS: {
1260 u8 qualifier = spec.qualifier;
1261
1262 if (qualifier == 'l') {
1263 long *ip = va_arg(args, long *);
1264 *ip = (str - buf);
1265 } else if (TOLOWER(qualifier) == 'z') {
1266 size_t *ip = va_arg(args, size_t *);
1267 *ip = (str - buf);
1268 } else {
1269 int *ip = va_arg(args, int *);
1270 *ip = (str - buf);
1271 }
1272 break;
1273 }
1274
1275 default:
1276 switch (spec.type) {
1277 case FORMAT_TYPE_LONG_LONG:
1278 num = va_arg(args, long long);
1279 break;
1280 case FORMAT_TYPE_ULONG:
1281 num = va_arg(args, unsigned long);
1282 break;
1283 case FORMAT_TYPE_LONG:
1284 num = va_arg(args, long);
1285 break;
1286 case FORMAT_TYPE_SIZE_T:
1287 num = va_arg(args, size_t);
1288 break;
1289 case FORMAT_TYPE_PTRDIFF:
1290 num = va_arg(args, ptrdiff_t);
1291 break;
1292 case FORMAT_TYPE_UBYTE:
1293 num = (unsigned char) va_arg(args, int);
1294 break;
1295 case FORMAT_TYPE_BYTE:
1296 num = (signed char) va_arg(args, int);
1297 break;
1298 case FORMAT_TYPE_USHORT:
1299 num = (unsigned short) va_arg(args, int);
1300 break;
1301 case FORMAT_TYPE_SHORT:
1302 num = (short) va_arg(args, int);
1303 break;
1304 case FORMAT_TYPE_INT:
1305 num = (int) va_arg(args, int);
1306 break;
1307 default:
1308 num = va_arg(args, unsigned int);
1309 }
1310
1311 str = number(str, end, num, spec);
1312 }
1313 }
1314
1315 if (size > 0) {
1316 if (str < end)
1317 *str = '\0';
1318 else
1319 end[-1] = '\0';
1320 }
1321
1322 /* the trailing null byte doesn't count towards the total */
1323 return str-buf;
1324
1325 }
1326 EXPORT_SYMBOL(vsnprintf);
1327
1328 /**
1329 * vscnprintf - Format a string and place it in a buffer
1330 * @buf: The buffer to place the result into
1331 * @size: The size of the buffer, including the trailing null space
1332 * @fmt: The format string to use
1333 * @args: Arguments for the format string
1334 *
1335 * The return value is the number of characters which have been written into
1336 * the @buf not including the trailing '\0'. If @size is == 0 the function
1337 * returns 0.
1338 *
1339 * Call this function if you are already dealing with a va_list.
1340 * You probably want scnprintf() instead.
1341 *
1342 * See the vsnprintf() documentation for format string extensions over C99.
1343 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)1344 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1345 {
1346 int i;
1347
1348 i = vsnprintf(buf, size, fmt, args);
1349
1350 if (likely(i < size))
1351 return i;
1352 if (size != 0)
1353 return size - 1;
1354 return 0;
1355 }
1356 EXPORT_SYMBOL(vscnprintf);
1357
1358 /**
1359 * snprintf - Format a string and place it in a buffer
1360 * @buf: The buffer to place the result into
1361 * @size: The size of the buffer, including the trailing null space
1362 * @fmt: The format string to use
1363 * @...: Arguments for the format string
1364 *
1365 * The return value is the number of characters which would be
1366 * generated for the given input, excluding the trailing null,
1367 * as per ISO C99. If the return is greater than or equal to
1368 * @size, the resulting string is truncated.
1369 *
1370 * See the vsnprintf() documentation for format string extensions over C99.
1371 */
snprintf(char * buf,size_t size,const char * fmt,...)1372 int snprintf(char *buf, size_t size, const char *fmt, ...)
1373 {
1374 va_list args;
1375 int i;
1376
1377 va_start(args, fmt);
1378 i = vsnprintf(buf, size, fmt, args);
1379 va_end(args);
1380
1381 return i;
1382 }
1383 EXPORT_SYMBOL(snprintf);
1384
1385 /**
1386 * scnprintf - Format a string and place it in a buffer
1387 * @buf: The buffer to place the result into
1388 * @size: The size of the buffer, including the trailing null space
1389 * @fmt: The format string to use
1390 * @...: Arguments for the format string
1391 *
1392 * The return value is the number of characters written into @buf not including
1393 * the trailing '\0'. If @size is == 0 the function returns 0.
1394 */
1395
scnprintf(char * buf,size_t size,const char * fmt,...)1396 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1397 {
1398 va_list args;
1399 int i;
1400
1401 va_start(args, fmt);
1402 i = vscnprintf(buf, size, fmt, args);
1403 va_end(args);
1404
1405 return i;
1406 }
1407 EXPORT_SYMBOL(scnprintf);
1408
1409 /**
1410 * vsprintf - Format a string and place it in a buffer
1411 * @buf: The buffer to place the result into
1412 * @fmt: The format string to use
1413 * @args: Arguments for the format string
1414 *
1415 * The function returns the number of characters written
1416 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1417 * buffer overflows.
1418 *
1419 * Call this function if you are already dealing with a va_list.
1420 * You probably want sprintf() instead.
1421 *
1422 * See the vsnprintf() documentation for format string extensions over C99.
1423 */
vsprintf(char * buf,const char * fmt,va_list args)1424 int vsprintf(char *buf, const char *fmt, va_list args)
1425 {
1426 return vsnprintf(buf, INT_MAX, fmt, args);
1427 }
1428 EXPORT_SYMBOL(vsprintf);
1429
1430 /**
1431 * sprintf - Format a string and place it in a buffer
1432 * @buf: The buffer to place the result into
1433 * @fmt: The format string to use
1434 * @...: Arguments for the format string
1435 *
1436 * The function returns the number of characters written
1437 * into @buf. Use snprintf() or scnprintf() in order to avoid
1438 * buffer overflows.
1439 *
1440 * See the vsnprintf() documentation for format string extensions over C99.
1441 */
sprintf(char * buf,const char * fmt,...)1442 int sprintf(char *buf, const char *fmt, ...)
1443 {
1444 va_list args;
1445 int i;
1446
1447 va_start(args, fmt);
1448 i = vsnprintf(buf, INT_MAX, fmt, args);
1449 va_end(args);
1450
1451 return i;
1452 }
1453 EXPORT_SYMBOL(sprintf);
1454
1455 #ifdef CONFIG_BINARY_PRINTF
1456 /*
1457 * bprintf service:
1458 * vbin_printf() - VA arguments to binary data
1459 * bstr_printf() - Binary data to text string
1460 */
1461
1462 /**
1463 * vbin_printf - Parse a format string and place args' binary value in a buffer
1464 * @bin_buf: The buffer to place args' binary value
1465 * @size: The size of the buffer(by words(32bits), not characters)
1466 * @fmt: The format string to use
1467 * @args: Arguments for the format string
1468 *
1469 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1470 * is skiped.
1471 *
1472 * The return value is the number of words(32bits) which would be generated for
1473 * the given input.
1474 *
1475 * NOTE:
1476 * If the return value is greater than @size, the resulting bin_buf is NOT
1477 * valid for bstr_printf().
1478 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt,va_list args)1479 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1480 {
1481 struct printf_spec spec = {0};
1482 char *str, *end;
1483
1484 str = (char *)bin_buf;
1485 end = (char *)(bin_buf + size);
1486
1487 #define save_arg(type) \
1488 do { \
1489 if (sizeof(type) == 8) { \
1490 unsigned long long value; \
1491 str = PTR_ALIGN(str, sizeof(u32)); \
1492 value = va_arg(args, unsigned long long); \
1493 if (str + sizeof(type) <= end) { \
1494 *(u32 *)str = *(u32 *)&value; \
1495 *(u32 *)(str + 4) = *((u32 *)&value + 1); \
1496 } \
1497 } else { \
1498 unsigned long value; \
1499 str = PTR_ALIGN(str, sizeof(type)); \
1500 value = va_arg(args, int); \
1501 if (str + sizeof(type) <= end) \
1502 *(typeof(type) *)str = (type)value; \
1503 } \
1504 str += sizeof(type); \
1505 } while (0)
1506
1507 while (*fmt) {
1508 int read = format_decode(fmt, &spec);
1509
1510 fmt += read;
1511
1512 switch (spec.type) {
1513 case FORMAT_TYPE_NONE:
1514 case FORMAT_TYPE_INVALID:
1515 case FORMAT_TYPE_PERCENT_CHAR:
1516 break;
1517
1518 case FORMAT_TYPE_WIDTH:
1519 case FORMAT_TYPE_PRECISION:
1520 save_arg(int);
1521 break;
1522
1523 case FORMAT_TYPE_CHAR:
1524 save_arg(char);
1525 break;
1526
1527 case FORMAT_TYPE_STR: {
1528 const char *save_str = va_arg(args, char *);
1529 size_t len;
1530
1531 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1532 || (unsigned long)save_str < PAGE_SIZE)
1533 save_str = "(null)";
1534 len = strlen(save_str) + 1;
1535 if (str + len < end)
1536 memcpy(str, save_str, len);
1537 str += len;
1538 break;
1539 }
1540
1541 case FORMAT_TYPE_PTR:
1542 save_arg(void *);
1543 /* skip all alphanumeric pointer suffixes */
1544 while (isalnum(*fmt))
1545 fmt++;
1546 break;
1547
1548 case FORMAT_TYPE_NRCHARS: {
1549 /* skip %n 's argument */
1550 u8 qualifier = spec.qualifier;
1551 void *skip_arg;
1552 if (qualifier == 'l')
1553 skip_arg = va_arg(args, long *);
1554 else if (TOLOWER(qualifier) == 'z')
1555 skip_arg = va_arg(args, size_t *);
1556 else
1557 skip_arg = va_arg(args, int *);
1558 break;
1559 }
1560
1561 default:
1562 switch (spec.type) {
1563
1564 case FORMAT_TYPE_LONG_LONG:
1565 save_arg(long long);
1566 break;
1567 case FORMAT_TYPE_ULONG:
1568 case FORMAT_TYPE_LONG:
1569 save_arg(unsigned long);
1570 break;
1571 case FORMAT_TYPE_SIZE_T:
1572 save_arg(size_t);
1573 break;
1574 case FORMAT_TYPE_PTRDIFF:
1575 save_arg(ptrdiff_t);
1576 break;
1577 case FORMAT_TYPE_UBYTE:
1578 case FORMAT_TYPE_BYTE:
1579 save_arg(char);
1580 break;
1581 case FORMAT_TYPE_USHORT:
1582 case FORMAT_TYPE_SHORT:
1583 save_arg(short);
1584 break;
1585 default:
1586 save_arg(int);
1587 }
1588 }
1589 }
1590
1591 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1592 #undef save_arg
1593 }
1594 EXPORT_SYMBOL_GPL(vbin_printf);
1595
1596 /**
1597 * bstr_printf - Format a string from binary arguments and place it in a buffer
1598 * @buf: The buffer to place the result into
1599 * @size: The size of the buffer, including the trailing null space
1600 * @fmt: The format string to use
1601 * @bin_buf: Binary arguments for the format string
1602 *
1603 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1604 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1605 * a binary buffer that generated by vbin_printf.
1606 *
1607 * The format follows C99 vsnprintf, but has some extensions:
1608 * see vsnprintf comment for details.
1609 *
1610 * The return value is the number of characters which would
1611 * be generated for the given input, excluding the trailing
1612 * '\0', as per ISO C99. If you want to have the exact
1613 * number of characters written into @buf as return value
1614 * (not including the trailing '\0'), use vscnprintf(). If the
1615 * return is greater than or equal to @size, the resulting
1616 * string is truncated.
1617 */
bstr_printf(char * buf,size_t size,const char * fmt,const u32 * bin_buf)1618 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1619 {
1620 struct printf_spec spec = {0};
1621 char *str, *end;
1622 const char *args = (const char *)bin_buf;
1623
1624 if (WARN_ON_ONCE((int) size < 0))
1625 return 0;
1626
1627 str = buf;
1628 end = buf + size;
1629
1630 #define get_arg(type) \
1631 ({ \
1632 typeof(type) value; \
1633 if (sizeof(type) == 8) { \
1634 args = PTR_ALIGN(args, sizeof(u32)); \
1635 *(u32 *)&value = *(u32 *)args; \
1636 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
1637 } else { \
1638 args = PTR_ALIGN(args, sizeof(type)); \
1639 value = *(typeof(type) *)args; \
1640 } \
1641 args += sizeof(type); \
1642 value; \
1643 })
1644
1645 /* Make sure end is always >= buf */
1646 if (end < buf) {
1647 end = ((void *)-1);
1648 size = end - buf;
1649 }
1650
1651 while (*fmt) {
1652 const char *old_fmt = fmt;
1653 int read = format_decode(fmt, &spec);
1654
1655 fmt += read;
1656
1657 switch (spec.type) {
1658 case FORMAT_TYPE_NONE: {
1659 int copy = read;
1660 if (str < end) {
1661 if (copy > end - str)
1662 copy = end - str;
1663 memcpy(str, old_fmt, copy);
1664 }
1665 str += read;
1666 break;
1667 }
1668
1669 case FORMAT_TYPE_WIDTH:
1670 spec.field_width = get_arg(int);
1671 break;
1672
1673 case FORMAT_TYPE_PRECISION:
1674 spec.precision = get_arg(int);
1675 break;
1676
1677 case FORMAT_TYPE_CHAR: {
1678 char c;
1679
1680 if (!(spec.flags & LEFT)) {
1681 while (--spec.field_width > 0) {
1682 if (str < end)
1683 *str = ' ';
1684 ++str;
1685 }
1686 }
1687 c = (unsigned char) get_arg(char);
1688 if (str < end)
1689 *str = c;
1690 ++str;
1691 while (--spec.field_width > 0) {
1692 if (str < end)
1693 *str = ' ';
1694 ++str;
1695 }
1696 break;
1697 }
1698
1699 case FORMAT_TYPE_STR: {
1700 const char *str_arg = args;
1701 args += strlen(str_arg) + 1;
1702 str = string(str, end, (char *)str_arg, spec);
1703 break;
1704 }
1705
1706 case FORMAT_TYPE_PTR:
1707 str = pointer(fmt+1, str, end, get_arg(void *), spec);
1708 while (isalnum(*fmt))
1709 fmt++;
1710 break;
1711
1712 case FORMAT_TYPE_PERCENT_CHAR:
1713 case FORMAT_TYPE_INVALID:
1714 if (str < end)
1715 *str = '%';
1716 ++str;
1717 break;
1718
1719 case FORMAT_TYPE_NRCHARS:
1720 /* skip */
1721 break;
1722
1723 default: {
1724 unsigned long long num;
1725
1726 switch (spec.type) {
1727
1728 case FORMAT_TYPE_LONG_LONG:
1729 num = get_arg(long long);
1730 break;
1731 case FORMAT_TYPE_ULONG:
1732 case FORMAT_TYPE_LONG:
1733 num = get_arg(unsigned long);
1734 break;
1735 case FORMAT_TYPE_SIZE_T:
1736 num = get_arg(size_t);
1737 break;
1738 case FORMAT_TYPE_PTRDIFF:
1739 num = get_arg(ptrdiff_t);
1740 break;
1741 case FORMAT_TYPE_UBYTE:
1742 num = get_arg(unsigned char);
1743 break;
1744 case FORMAT_TYPE_BYTE:
1745 num = get_arg(signed char);
1746 break;
1747 case FORMAT_TYPE_USHORT:
1748 num = get_arg(unsigned short);
1749 break;
1750 case FORMAT_TYPE_SHORT:
1751 num = get_arg(short);
1752 break;
1753 case FORMAT_TYPE_UINT:
1754 num = get_arg(unsigned int);
1755 break;
1756 default:
1757 num = get_arg(int);
1758 }
1759
1760 str = number(str, end, num, spec);
1761 } /* default: */
1762 } /* switch(spec.type) */
1763 } /* while(*fmt) */
1764
1765 if (size > 0) {
1766 if (str < end)
1767 *str = '\0';
1768 else
1769 end[-1] = '\0';
1770 }
1771
1772 #undef get_arg
1773
1774 /* the trailing null byte doesn't count towards the total */
1775 return str - buf;
1776 }
1777 EXPORT_SYMBOL_GPL(bstr_printf);
1778
1779 /**
1780 * bprintf - Parse a format string and place args' binary value in a buffer
1781 * @bin_buf: The buffer to place args' binary value
1782 * @size: The size of the buffer(by words(32bits), not characters)
1783 * @fmt: The format string to use
1784 * @...: Arguments for the format string
1785 *
1786 * The function returns the number of words(u32) written
1787 * into @bin_buf.
1788 */
bprintf(u32 * bin_buf,size_t size,const char * fmt,...)1789 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1790 {
1791 va_list args;
1792 int ret;
1793
1794 va_start(args, fmt);
1795 ret = vbin_printf(bin_buf, size, fmt, args);
1796 va_end(args);
1797
1798 return ret;
1799 }
1800 EXPORT_SYMBOL_GPL(bprintf);
1801
1802 #endif /* CONFIG_BINARY_PRINTF */
1803
1804 /**
1805 * vsscanf - Unformat a buffer into a list of arguments
1806 * @buf: input buffer
1807 * @fmt: format of buffer
1808 * @args: arguments
1809 */
vsscanf(const char * buf,const char * fmt,va_list args)1810 int vsscanf(const char *buf, const char *fmt, va_list args)
1811 {
1812 const char *str = buf;
1813 char *next;
1814 char digit;
1815 int num = 0;
1816 u8 qualifier;
1817 u8 base;
1818 s16 field_width;
1819 bool is_sign;
1820
1821 while (*fmt && *str) {
1822 /* skip any white space in format */
1823 /* white space in format matchs any amount of
1824 * white space, including none, in the input.
1825 */
1826 if (isspace(*fmt)) {
1827 fmt = skip_spaces(++fmt);
1828 str = skip_spaces(str);
1829 }
1830
1831 /* anything that is not a conversion must match exactly */
1832 if (*fmt != '%' && *fmt) {
1833 if (*fmt++ != *str++)
1834 break;
1835 continue;
1836 }
1837
1838 if (!*fmt)
1839 break;
1840 ++fmt;
1841
1842 /* skip this conversion.
1843 * advance both strings to next white space
1844 */
1845 if (*fmt == '*') {
1846 while (!isspace(*fmt) && *fmt != '%' && *fmt)
1847 fmt++;
1848 while (!isspace(*str) && *str)
1849 str++;
1850 continue;
1851 }
1852
1853 /* get field width */
1854 field_width = -1;
1855 if (isdigit(*fmt))
1856 field_width = skip_atoi(&fmt);
1857
1858 /* get conversion qualifier */
1859 qualifier = -1;
1860 if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1861 TOLOWER(*fmt) == 'z') {
1862 qualifier = *fmt++;
1863 if (unlikely(qualifier == *fmt)) {
1864 if (qualifier == 'h') {
1865 qualifier = 'H';
1866 fmt++;
1867 } else if (qualifier == 'l') {
1868 qualifier = 'L';
1869 fmt++;
1870 }
1871 }
1872 }
1873
1874 if (!*fmt || !*str)
1875 break;
1876
1877 base = 10;
1878 is_sign = 0;
1879
1880 switch (*fmt++) {
1881 case 'c':
1882 {
1883 char *s = (char *)va_arg(args, char*);
1884 if (field_width == -1)
1885 field_width = 1;
1886 do {
1887 *s++ = *str++;
1888 } while (--field_width > 0 && *str);
1889 num++;
1890 }
1891 continue;
1892 case 's':
1893 {
1894 char *s = (char *)va_arg(args, char *);
1895 if (field_width == -1)
1896 field_width = SHRT_MAX;
1897 /* first, skip leading white space in buffer */
1898 str = skip_spaces(str);
1899
1900 /* now copy until next white space */
1901 while (*str && !isspace(*str) && field_width--)
1902 *s++ = *str++;
1903 *s = '\0';
1904 num++;
1905 }
1906 continue;
1907 case 'n':
1908 /* return number of characters read so far */
1909 {
1910 int *i = (int *)va_arg(args, int*);
1911 *i = str - buf;
1912 }
1913 continue;
1914 case 'o':
1915 base = 8;
1916 break;
1917 case 'x':
1918 case 'X':
1919 base = 16;
1920 break;
1921 case 'i':
1922 base = 0;
1923 case 'd':
1924 is_sign = 1;
1925 case 'u':
1926 break;
1927 case '%':
1928 /* looking for '%' in str */
1929 if (*str++ != '%')
1930 return num;
1931 continue;
1932 default:
1933 /* invalid format; stop here */
1934 return num;
1935 }
1936
1937 /* have some sort of integer conversion.
1938 * first, skip white space in buffer.
1939 */
1940 str = skip_spaces(str);
1941
1942 digit = *str;
1943 if (is_sign && digit == '-')
1944 digit = *(str + 1);
1945
1946 if (!digit
1947 || (base == 16 && !isxdigit(digit))
1948 || (base == 10 && !isdigit(digit))
1949 || (base == 8 && (!isdigit(digit) || digit > '7'))
1950 || (base == 0 && !isdigit(digit)))
1951 break;
1952
1953 switch (qualifier) {
1954 case 'H': /* that's 'hh' in format */
1955 if (is_sign) {
1956 signed char *s = (signed char *)va_arg(args, signed char *);
1957 *s = (signed char)simple_strtol(str, &next, base);
1958 } else {
1959 unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1960 *s = (unsigned char)simple_strtoul(str, &next, base);
1961 }
1962 break;
1963 case 'h':
1964 if (is_sign) {
1965 short *s = (short *)va_arg(args, short *);
1966 *s = (short)simple_strtol(str, &next, base);
1967 } else {
1968 unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
1969 *s = (unsigned short)simple_strtoul(str, &next, base);
1970 }
1971 break;
1972 case 'l':
1973 if (is_sign) {
1974 long *l = (long *)va_arg(args, long *);
1975 *l = simple_strtol(str, &next, base);
1976 } else {
1977 unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
1978 *l = simple_strtoul(str, &next, base);
1979 }
1980 break;
1981 case 'L':
1982 if (is_sign) {
1983 long long *l = (long long *)va_arg(args, long long *);
1984 *l = simple_strtoll(str, &next, base);
1985 } else {
1986 unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
1987 *l = simple_strtoull(str, &next, base);
1988 }
1989 break;
1990 case 'Z':
1991 case 'z':
1992 {
1993 size_t *s = (size_t *)va_arg(args, size_t *);
1994 *s = (size_t)simple_strtoul(str, &next, base);
1995 }
1996 break;
1997 default:
1998 if (is_sign) {
1999 int *i = (int *)va_arg(args, int *);
2000 *i = (int)simple_strtol(str, &next, base);
2001 } else {
2002 unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2003 *i = (unsigned int)simple_strtoul(str, &next, base);
2004 }
2005 break;
2006 }
2007 num++;
2008
2009 if (!next)
2010 break;
2011 str = next;
2012 }
2013
2014 /*
2015 * Now we've come all the way through so either the input string or the
2016 * format ended. In the former case, there can be a %n at the current
2017 * position in the format that needs to be filled.
2018 */
2019 if (*fmt == '%' && *(fmt + 1) == 'n') {
2020 int *p = (int *)va_arg(args, int *);
2021 *p = str - buf;
2022 }
2023
2024 return num;
2025 }
2026 EXPORT_SYMBOL(vsscanf);
2027
2028 /**
2029 * sscanf - Unformat a buffer into a list of arguments
2030 * @buf: input buffer
2031 * @fmt: formatting of buffer
2032 * @...: resulting arguments
2033 */
sscanf(const char * buf,const char * fmt,...)2034 int sscanf(const char *buf, const char *fmt, ...)
2035 {
2036 va_list args;
2037 int i;
2038
2039 va_start(args, fmt);
2040 i = vsscanf(buf, fmt, args);
2041 va_end(args);
2042
2043 return i;
2044 }
2045 EXPORT_SYMBOL(sscanf);
2046