xref: /linux/lib/vsprintf.c (revision 98b8788ae91694499d1995035625bea16a4db0c4)
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 
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_strtoul - convert a string to an unsigned 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  */
55 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
56 {
57 	unsigned 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 
75 	if (endp)
76 		*endp = (char *)cp;
77 	return result;
78 }
79 EXPORT_SYMBOL(simple_strtoul);
80 
81 /**
82  * simple_strtol - convert a string to a signed 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  */
87 long simple_strtol(const char *cp, char **endp, unsigned int base)
88 {
89 	if(*cp == '-')
90 		return -simple_strtoul(cp + 1, endp, base);
91 	return simple_strtoul(cp, endp, base);
92 }
93 EXPORT_SYMBOL(simple_strtol);
94 
95 /**
96  * simple_strtoull - convert a string to an unsigned long long
97  * @cp: The start of the string
98  * @endp: A pointer to the end of the parsed string will be placed here
99  * @base: The number base to use
100  */
101 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
102 {
103 	unsigned long long result = 0;
104 
105 	if (!base)
106 		base = simple_guess_base(cp);
107 
108 	if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
109 		cp += 2;
110 
111 	while (isxdigit(*cp)) {
112 		unsigned int value;
113 
114 		value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
115 		if (value >= base)
116 			break;
117 		result = result * base + value;
118 		cp++;
119 	}
120 
121 	if (endp)
122 		*endp = (char *)cp;
123 	return result;
124 }
125 EXPORT_SYMBOL(simple_strtoull);
126 
127 /**
128  * simple_strtoll - convert a string to a signed long long
129  * @cp: The start of the string
130  * @endp: A pointer to the end of the parsed string will be placed here
131  * @base: The number base to use
132  */
133 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
134 {
135 	if(*cp=='-')
136 		return -simple_strtoull(cp + 1, endp, base);
137 	return simple_strtoull(cp, endp, base);
138 }
139 
140 /**
141  * strict_strtoul - convert a string to an unsigned long strictly
142  * @cp: The string to be converted
143  * @base: The number base to use
144  * @res: The converted result value
145  *
146  * strict_strtoul converts a string to an unsigned long only if the
147  * string is really an unsigned long string, any string containing
148  * any invalid char at the tail will be rejected and -EINVAL is returned,
149  * only a newline char at the tail is acceptible because people generally
150  * change a module parameter in the following way:
151  *
152  * 	echo 1024 > /sys/module/e1000/parameters/copybreak
153  *
154  * echo will append a newline to the tail.
155  *
156  * It returns 0 if conversion is successful and *res is set to the converted
157  * value, otherwise it returns -EINVAL and *res is set to 0.
158  *
159  * simple_strtoul just ignores the successive invalid characters and
160  * return the converted value of prefix part of the string.
161  */
162 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
163 {
164 	char *tail;
165 	unsigned long val;
166 	size_t len;
167 
168 	*res = 0;
169 	len = strlen(cp);
170 	if (len == 0)
171 		return -EINVAL;
172 
173 	val = simple_strtoul(cp, &tail, base);
174 	if (tail == cp)
175 		return -EINVAL;
176 	if ((*tail == '\0') ||
177 		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
178 		*res = val;
179 		return 0;
180 	}
181 
182 	return -EINVAL;
183 }
184 EXPORT_SYMBOL(strict_strtoul);
185 
186 /**
187  * strict_strtol - convert a string to a long strictly
188  * @cp: The string to be converted
189  * @base: The number base to use
190  * @res: The converted result value
191  *
192  * strict_strtol is similiar to strict_strtoul, but it allows the first
193  * character of a string is '-'.
194  *
195  * It returns 0 if conversion is successful and *res is set to the converted
196  * value, otherwise it returns -EINVAL and *res is set to 0.
197  */
198 int strict_strtol(const char *cp, unsigned int base, long *res)
199 {
200 	int ret;
201 	if (*cp == '-') {
202 		ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
203 		if (!ret)
204 			*res = -(*res);
205 	} else {
206 		ret = strict_strtoul(cp, base, (unsigned long *)res);
207 	}
208 
209 	return ret;
210 }
211 EXPORT_SYMBOL(strict_strtol);
212 
213 /**
214  * strict_strtoull - convert a string to an unsigned long long strictly
215  * @cp: The string to be converted
216  * @base: The number base to use
217  * @res: The converted result value
218  *
219  * strict_strtoull converts a string to an unsigned long long only if the
220  * string is really an unsigned long long string, any string containing
221  * any invalid char at the tail will be rejected and -EINVAL is returned,
222  * only a newline char at the tail is acceptible because people generally
223  * change a module parameter in the following way:
224  *
225  * 	echo 1024 > /sys/module/e1000/parameters/copybreak
226  *
227  * echo will append a newline to the tail of the string.
228  *
229  * It returns 0 if conversion is successful and *res is set to the converted
230  * value, otherwise it returns -EINVAL and *res is set to 0.
231  *
232  * simple_strtoull just ignores the successive invalid characters and
233  * return the converted value of prefix part of the string.
234  */
235 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
236 {
237 	char *tail;
238 	unsigned long long val;
239 	size_t len;
240 
241 	*res = 0;
242 	len = strlen(cp);
243 	if (len == 0)
244 		return -EINVAL;
245 
246 	val = simple_strtoull(cp, &tail, base);
247 	if (tail == cp)
248 		return -EINVAL;
249 	if ((*tail == '\0') ||
250 		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
251 		*res = val;
252 		return 0;
253 	}
254 
255 	return -EINVAL;
256 }
257 EXPORT_SYMBOL(strict_strtoull);
258 
259 /**
260  * strict_strtoll - convert a string to a long long strictly
261  * @cp: The string to be converted
262  * @base: The number base to use
263  * @res: The converted result value
264  *
265  * strict_strtoll is similiar to strict_strtoull, but it allows the first
266  * character of a string is '-'.
267  *
268  * It returns 0 if conversion is successful and *res is set to the converted
269  * value, otherwise it returns -EINVAL and *res is set to 0.
270  */
271 int strict_strtoll(const char *cp, unsigned int base, long long *res)
272 {
273 	int ret;
274 	if (*cp == '-') {
275 		ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
276 		if (!ret)
277 			*res = -(*res);
278 	} else {
279 		ret = strict_strtoull(cp, base, (unsigned long long *)res);
280 	}
281 
282 	return ret;
283 }
284 EXPORT_SYMBOL(strict_strtoll);
285 
286 static int skip_atoi(const char **s)
287 {
288 	int i=0;
289 
290 	while (isdigit(**s))
291 		i = i*10 + *((*s)++) - '0';
292 	return i;
293 }
294 
295 /* Decimal conversion is by far the most typical, and is used
296  * for /proc and /sys data. This directly impacts e.g. top performance
297  * with many processes running. We optimize it for speed
298  * using code from
299  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
300  * (with permission from the author, Douglas W. Jones). */
301 
302 /* Formats correctly any integer in [0,99999].
303  * Outputs from one to five digits depending on input.
304  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
305 static char* put_dec_trunc(char *buf, unsigned q)
306 {
307 	unsigned d3, d2, d1, d0;
308 	d1 = (q>>4) & 0xf;
309 	d2 = (q>>8) & 0xf;
310 	d3 = (q>>12);
311 
312 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
313 	q = (d0 * 0xcd) >> 11;
314 	d0 = d0 - 10*q;
315 	*buf++ = d0 + '0'; /* least significant digit */
316 	d1 = q + 9*d3 + 5*d2 + d1;
317 	if (d1 != 0) {
318 		q = (d1 * 0xcd) >> 11;
319 		d1 = d1 - 10*q;
320 		*buf++ = d1 + '0'; /* next digit */
321 
322 		d2 = q + 2*d2;
323 		if ((d2 != 0) || (d3 != 0)) {
324 			q = (d2 * 0xd) >> 7;
325 			d2 = d2 - 10*q;
326 			*buf++ = d2 + '0'; /* next digit */
327 
328 			d3 = q + 4*d3;
329 			if (d3 != 0) {
330 				q = (d3 * 0xcd) >> 11;
331 				d3 = d3 - 10*q;
332 				*buf++ = d3 + '0';  /* next digit */
333 				if (q != 0)
334 					*buf++ = q + '0';  /* most sign. digit */
335 			}
336 		}
337 	}
338 	return buf;
339 }
340 /* Same with if's removed. Always emits five digits */
341 static char* put_dec_full(char *buf, unsigned q)
342 {
343 	/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
344 	/* but anyway, gcc produces better code with full-sized ints */
345 	unsigned d3, d2, d1, d0;
346 	d1 = (q>>4) & 0xf;
347 	d2 = (q>>8) & 0xf;
348 	d3 = (q>>12);
349 
350 	/* Possible ways to approx. divide by 10 */
351 	/* gcc -O2 replaces multiply with shifts and adds */
352 	// (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
353 	// (x * 0x67) >> 10:  1100111
354 	// (x * 0x34) >> 9:    110100 - same
355 	// (x * 0x1a) >> 8:     11010 - same
356 	// (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
357 
358 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
359 	q = (d0 * 0xcd) >> 11;
360 	d0 = d0 - 10*q;
361 	*buf++ = d0 + '0';
362 	d1 = q + 9*d3 + 5*d2 + d1;
363 		q = (d1 * 0xcd) >> 11;
364 		d1 = d1 - 10*q;
365 		*buf++ = d1 + '0';
366 
367 		d2 = q + 2*d2;
368 			q = (d2 * 0xd) >> 7;
369 			d2 = d2 - 10*q;
370 			*buf++ = d2 + '0';
371 
372 			d3 = q + 4*d3;
373 				q = (d3 * 0xcd) >> 11; /* - shorter code */
374 				/* q = (d3 * 0x67) >> 10; - would also work */
375 				d3 = d3 - 10*q;
376 				*buf++ = d3 + '0';
377 					*buf++ = q + '0';
378 	return buf;
379 }
380 /* No inlining helps gcc to use registers better */
381 static noinline char* put_dec(char *buf, unsigned long long num)
382 {
383 	while (1) {
384 		unsigned rem;
385 		if (num < 100000)
386 			return put_dec_trunc(buf, num);
387 		rem = do_div(num, 100000);
388 		buf = put_dec_full(buf, rem);
389 	}
390 }
391 
392 #define ZEROPAD	1		/* pad with zero */
393 #define SIGN	2		/* unsigned/signed long */
394 #define PLUS	4		/* show plus */
395 #define SPACE	8		/* space if plus */
396 #define LEFT	16		/* left justified */
397 #define SMALL	32		/* Must be 32 == 0x20 */
398 #define SPECIAL	64		/* 0x */
399 
400 enum format_type {
401 	FORMAT_TYPE_NONE, /* Just a string part */
402 	FORMAT_TYPE_WIDTH,
403 	FORMAT_TYPE_PRECISION,
404 	FORMAT_TYPE_CHAR,
405 	FORMAT_TYPE_STR,
406 	FORMAT_TYPE_PTR,
407 	FORMAT_TYPE_PERCENT_CHAR,
408 	FORMAT_TYPE_INVALID,
409 	FORMAT_TYPE_LONG_LONG,
410 	FORMAT_TYPE_ULONG,
411 	FORMAT_TYPE_LONG,
412 	FORMAT_TYPE_UBYTE,
413 	FORMAT_TYPE_BYTE,
414 	FORMAT_TYPE_USHORT,
415 	FORMAT_TYPE_SHORT,
416 	FORMAT_TYPE_UINT,
417 	FORMAT_TYPE_INT,
418 	FORMAT_TYPE_NRCHARS,
419 	FORMAT_TYPE_SIZE_T,
420 	FORMAT_TYPE_PTRDIFF
421 };
422 
423 struct printf_spec {
424 	enum format_type	type;
425 	int			flags;		/* flags to number() */
426 	int			field_width;	/* width of output field */
427 	int			base;
428 	int			precision;	/* # of digits/chars */
429 	int			qualifier;
430 };
431 
432 static char *number(char *buf, char *end, unsigned long long num,
433 			struct printf_spec spec)
434 {
435 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
436 	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
437 
438 	char tmp[66];
439 	char sign;
440 	char locase;
441 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
442 	int i;
443 
444 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
445 	 * produces same digits or (maybe lowercased) letters */
446 	locase = (spec.flags & SMALL);
447 	if (spec.flags & LEFT)
448 		spec.flags &= ~ZEROPAD;
449 	sign = 0;
450 	if (spec.flags & SIGN) {
451 		if ((signed long long) num < 0) {
452 			sign = '-';
453 			num = - (signed long long) num;
454 			spec.field_width--;
455 		} else if (spec.flags & PLUS) {
456 			sign = '+';
457 			spec.field_width--;
458 		} else if (spec.flags & SPACE) {
459 			sign = ' ';
460 			spec.field_width--;
461 		}
462 	}
463 	if (need_pfx) {
464 		spec.field_width--;
465 		if (spec.base == 16)
466 			spec.field_width--;
467 	}
468 
469 	/* generate full string in tmp[], in reverse order */
470 	i = 0;
471 	if (num == 0)
472 		tmp[i++] = '0';
473 	/* Generic code, for any base:
474 	else do {
475 		tmp[i++] = (digits[do_div(num,base)] | locase);
476 	} while (num != 0);
477 	*/
478 	else if (spec.base != 10) { /* 8 or 16 */
479 		int mask = spec.base - 1;
480 		int shift = 3;
481 		if (spec.base == 16) shift = 4;
482 		do {
483 			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
484 			num >>= shift;
485 		} while (num);
486 	} else { /* base 10 */
487 		i = put_dec(tmp, num) - tmp;
488 	}
489 
490 	/* printing 100 using %2d gives "100", not "00" */
491 	if (i > spec.precision)
492 		spec.precision = i;
493 	/* leading space padding */
494 	spec.field_width -= spec.precision;
495 	if (!(spec.flags & (ZEROPAD+LEFT))) {
496 		while(--spec.field_width >= 0) {
497 			if (buf < end)
498 				*buf = ' ';
499 			++buf;
500 		}
501 	}
502 	/* sign */
503 	if (sign) {
504 		if (buf < end)
505 			*buf = sign;
506 		++buf;
507 	}
508 	/* "0x" / "0" prefix */
509 	if (need_pfx) {
510 		if (buf < end)
511 			*buf = '0';
512 		++buf;
513 		if (spec.base == 16) {
514 			if (buf < end)
515 				*buf = ('X' | locase);
516 			++buf;
517 		}
518 	}
519 	/* zero or space padding */
520 	if (!(spec.flags & LEFT)) {
521 		char c = (spec.flags & ZEROPAD) ? '0' : ' ';
522 		while (--spec.field_width >= 0) {
523 			if (buf < end)
524 				*buf = c;
525 			++buf;
526 		}
527 	}
528 	/* hmm even more zero padding? */
529 	while (i <= --spec.precision) {
530 		if (buf < end)
531 			*buf = '0';
532 		++buf;
533 	}
534 	/* actual digits of result */
535 	while (--i >= 0) {
536 		if (buf < end)
537 			*buf = tmp[i];
538 		++buf;
539 	}
540 	/* trailing space padding */
541 	while (--spec.field_width >= 0) {
542 		if (buf < end)
543 			*buf = ' ';
544 		++buf;
545 	}
546 	return buf;
547 }
548 
549 static char *string(char *buf, char *end, char *s, struct printf_spec spec)
550 {
551 	int len, i;
552 
553 	if ((unsigned long)s < PAGE_SIZE)
554 		s = "<NULL>";
555 
556 	len = strnlen(s, spec.precision);
557 
558 	if (!(spec.flags & LEFT)) {
559 		while (len < spec.field_width--) {
560 			if (buf < end)
561 				*buf = ' ';
562 			++buf;
563 		}
564 	}
565 	for (i = 0; i < len; ++i) {
566 		if (buf < end)
567 			*buf = *s;
568 		++buf; ++s;
569 	}
570 	while (len < spec.field_width--) {
571 		if (buf < end)
572 			*buf = ' ';
573 		++buf;
574 	}
575 	return buf;
576 }
577 
578 static char *symbol_string(char *buf, char *end, void *ptr,
579 				struct printf_spec spec, char ext)
580 {
581 	unsigned long value = (unsigned long) ptr;
582 #ifdef CONFIG_KALLSYMS
583 	char sym[KSYM_SYMBOL_LEN];
584 	if (ext != 'f' && ext != 's')
585 		sprint_symbol(sym, value);
586 	else
587 		kallsyms_lookup(value, NULL, NULL, NULL, sym);
588 	return string(buf, end, sym, spec);
589 #else
590 	spec.field_width = 2*sizeof(void *);
591 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
592 	spec.base = 16;
593 	return number(buf, end, value, spec);
594 #endif
595 }
596 
597 static char *resource_string(char *buf, char *end, struct resource *res,
598 				struct printf_spec spec, const char *fmt)
599 {
600 #ifndef IO_RSRC_PRINTK_SIZE
601 #define IO_RSRC_PRINTK_SIZE	6
602 #endif
603 
604 #ifndef MEM_RSRC_PRINTK_SIZE
605 #define MEM_RSRC_PRINTK_SIZE	10
606 #endif
607 	struct printf_spec hex_spec = {
608 		.base = 16,
609 		.precision = -1,
610 		.flags = SPECIAL | SMALL | ZEROPAD,
611 	};
612 	struct printf_spec dec_spec = {
613 		.base = 10,
614 		.precision = -1,
615 		.flags = 0,
616 	};
617 	struct printf_spec str_spec = {
618 		.field_width = -1,
619 		.precision = 10,
620 		.flags = LEFT,
621 	};
622 	struct printf_spec flag_spec = {
623 		.base = 16,
624 		.precision = -1,
625 		.flags = SPECIAL | SMALL,
626 	};
627 
628 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
629 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
630 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
631 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
632 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref disabled]")
633 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
634 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
635 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
636 
637 	char *p = sym, *pend = sym + sizeof(sym);
638 	int size = -1, addr = 0;
639 	int decode = (fmt[0] == 'R') ? 1 : 0;
640 
641 	if (res->flags & IORESOURCE_IO) {
642 		size = IO_RSRC_PRINTK_SIZE;
643 		addr = 1;
644 	} else if (res->flags & IORESOURCE_MEM) {
645 		size = MEM_RSRC_PRINTK_SIZE;
646 		addr = 1;
647 	}
648 
649 	*p++ = '[';
650 	if (res->flags & IORESOURCE_IO)
651 		p = string(p, pend, "io  ", str_spec);
652 	else if (res->flags & IORESOURCE_MEM)
653 		p = string(p, pend, "mem ", str_spec);
654 	else if (res->flags & IORESOURCE_IRQ)
655 		p = string(p, pend, "irq ", str_spec);
656 	else if (res->flags & IORESOURCE_DMA)
657 		p = string(p, pend, "dma ", str_spec);
658 	else {
659 		p = string(p, pend, "??? ", str_spec);
660 		decode = 0;
661 	}
662 	hex_spec.field_width = size;
663 	p = number(p, pend, res->start, addr ? hex_spec : dec_spec);
664 	if (res->start != res->end) {
665 		*p++ = '-';
666 		p = number(p, pend, res->end, addr ? hex_spec : dec_spec);
667 	}
668 	if (decode) {
669 		if (res->flags & IORESOURCE_MEM_64)
670 			p = string(p, pend, " 64bit", str_spec);
671 		if (res->flags & IORESOURCE_PREFETCH)
672 			p = string(p, pend, " pref", str_spec);
673 		if (res->flags & IORESOURCE_DISABLED)
674 			p = string(p, pend, " disabled", str_spec);
675 	} else {
676 		p = string(p, pend, " flags ", str_spec);
677 		p = number(p, pend, res->flags, flag_spec);
678 	}
679 	*p++ = ']';
680 	*p = '\0';
681 
682 	return string(buf, end, sym, spec);
683 }
684 
685 static char *mac_address_string(char *buf, char *end, u8 *addr,
686 				struct printf_spec spec, const char *fmt)
687 {
688 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
689 	char *p = mac_addr;
690 	int i;
691 
692 	for (i = 0; i < 6; i++) {
693 		p = pack_hex_byte(p, addr[i]);
694 		if (fmt[0] == 'M' && i != 5)
695 			*p++ = ':';
696 	}
697 	*p = '\0';
698 
699 	return string(buf, end, mac_addr, spec);
700 }
701 
702 static char *ip4_string(char *p, const u8 *addr, bool leading_zeros)
703 {
704 	int i;
705 
706 	for (i = 0; i < 4; i++) {
707 		char temp[3];	/* hold each IP quad in reverse order */
708 		int digits = put_dec_trunc(temp, addr[i]) - temp;
709 		if (leading_zeros) {
710 			if (digits < 3)
711 				*p++ = '0';
712 			if (digits < 2)
713 				*p++ = '0';
714 		}
715 		/* reverse the digits in the quad */
716 		while (digits--)
717 			*p++ = temp[digits];
718 		if (i < 3)
719 			*p++ = '.';
720 	}
721 
722 	*p = '\0';
723 	return p;
724 }
725 
726 static char *ip6_compressed_string(char *p, const char *addr)
727 {
728 	int i;
729 	int j;
730 	int range;
731 	unsigned char zerolength[8];
732 	int longest = 1;
733 	int colonpos = -1;
734 	u16 word;
735 	u8 hi;
736 	u8 lo;
737 	bool needcolon = false;
738 	bool useIPv4;
739 	struct in6_addr in6;
740 
741 	memcpy(&in6, addr, sizeof(struct in6_addr));
742 
743 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
744 
745 	memset(zerolength, 0, sizeof(zerolength));
746 
747 	if (useIPv4)
748 		range = 6;
749 	else
750 		range = 8;
751 
752 	/* find position of longest 0 run */
753 	for (i = 0; i < range; i++) {
754 		for (j = i; j < range; j++) {
755 			if (in6.s6_addr16[j] != 0)
756 				break;
757 			zerolength[i]++;
758 		}
759 	}
760 	for (i = 0; i < range; i++) {
761 		if (zerolength[i] > longest) {
762 			longest = zerolength[i];
763 			colonpos = i;
764 		}
765 	}
766 
767 	/* emit address */
768 	for (i = 0; i < range; i++) {
769 		if (i == colonpos) {
770 			if (needcolon || i == 0)
771 				*p++ = ':';
772 			*p++ = ':';
773 			needcolon = false;
774 			i += longest - 1;
775 			continue;
776 		}
777 		if (needcolon) {
778 			*p++ = ':';
779 			needcolon = false;
780 		}
781 		/* hex u16 without leading 0s */
782 		word = ntohs(in6.s6_addr16[i]);
783 		hi = word >> 8;
784 		lo = word & 0xff;
785 		if (hi) {
786 			if (hi > 0x0f)
787 				p = pack_hex_byte(p, hi);
788 			else
789 				*p++ = hex_asc_lo(hi);
790 		}
791 		if (hi || lo > 0x0f)
792 			p = pack_hex_byte(p, lo);
793 		else
794 			*p++ = hex_asc_lo(lo);
795 		needcolon = true;
796 	}
797 
798 	if (useIPv4) {
799 		if (needcolon)
800 			*p++ = ':';
801 		p = ip4_string(p, &in6.s6_addr[12], false);
802 	}
803 
804 	*p = '\0';
805 	return p;
806 }
807 
808 static char *ip6_string(char *p, const char *addr, const char *fmt)
809 {
810 	int i;
811 	for (i = 0; i < 8; i++) {
812 		p = pack_hex_byte(p, *addr++);
813 		p = pack_hex_byte(p, *addr++);
814 		if (fmt[0] == 'I' && i != 7)
815 			*p++ = ':';
816 	}
817 
818 	*p = '\0';
819 	return p;
820 }
821 
822 static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
823 			     struct printf_spec spec, const char *fmt)
824 {
825 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
826 
827 	if (fmt[0] == 'I' && fmt[2] == 'c')
828 		ip6_compressed_string(ip6_addr, addr);
829 	else
830 		ip6_string(ip6_addr, addr, fmt);
831 
832 	return string(buf, end, ip6_addr, spec);
833 }
834 
835 static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
836 			     struct printf_spec spec, const char *fmt)
837 {
838 	char ip4_addr[sizeof("255.255.255.255")];
839 
840 	ip4_string(ip4_addr, addr, fmt[0] == 'i');
841 
842 	return string(buf, end, ip4_addr, spec);
843 }
844 
845 /*
846  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
847  * by an extra set of alphanumeric characters that are extended format
848  * specifiers.
849  *
850  * Right now we handle:
851  *
852  * - 'F' For symbolic function descriptor pointers with offset
853  * - 'f' For simple symbolic function names without offset
854  * - 'S' For symbolic direct pointers with offset
855  * - 's' For symbolic direct pointers without offset
856  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
857  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
858  * - 'M' For a 6-byte MAC address, it prints the address in the
859  *       usual colon-separated hex notation
860  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
861  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
862  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
863  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
864  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
865  *       IPv6 omits the colons (01020304...0f)
866  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
867  * - 'I6c' for IPv6 addresses printed as specified by
868  *       http://www.ietf.org/id/draft-kawamura-ipv6-text-representation-03.txt
869  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
870  * function pointers are really function descriptors, which contain a
871  * pointer to the real address.
872  */
873 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
874 			struct printf_spec spec)
875 {
876 	if (!ptr)
877 		return string(buf, end, "(null)", spec);
878 
879 	switch (*fmt) {
880 	case 'F':
881 	case 'f':
882 		ptr = dereference_function_descriptor(ptr);
883 	case 's':
884 		/* Fallthrough */
885 	case 'S':
886 		return symbol_string(buf, end, ptr, spec, *fmt);
887 	case 'R':
888 	case 'r':
889 		return resource_string(buf, end, ptr, spec, fmt);
890 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
891 	case 'm':			/* Contiguous: 000102030405 */
892 		return mac_address_string(buf, end, ptr, spec, fmt);
893 	case 'I':			/* Formatted IP supported
894 					 * 4:	1.2.3.4
895 					 * 6:	0001:0203:...:0708
896 					 * 6c:	1::708 or 1::1.2.3.4
897 					 */
898 	case 'i':			/* Contiguous:
899 					 * 4:	001.002.003.004
900 					 * 6:   000102...0f
901 					 */
902 		switch (fmt[1]) {
903 		case '6':
904 			return ip6_addr_string(buf, end, ptr, spec, fmt);
905 		case '4':
906 			return ip4_addr_string(buf, end, ptr, spec, fmt);
907 		}
908 		break;
909 	}
910 	spec.flags |= SMALL;
911 	if (spec.field_width == -1) {
912 		spec.field_width = 2*sizeof(void *);
913 		spec.flags |= ZEROPAD;
914 	}
915 	spec.base = 16;
916 
917 	return number(buf, end, (unsigned long) ptr, spec);
918 }
919 
920 /*
921  * Helper function to decode printf style format.
922  * Each call decode a token from the format and return the
923  * number of characters read (or likely the delta where it wants
924  * to go on the next call).
925  * The decoded token is returned through the parameters
926  *
927  * 'h', 'l', or 'L' for integer fields
928  * 'z' support added 23/7/1999 S.H.
929  * 'z' changed to 'Z' --davidm 1/25/99
930  * 't' added for ptrdiff_t
931  *
932  * @fmt: the format string
933  * @type of the token returned
934  * @flags: various flags such as +, -, # tokens..
935  * @field_width: overwritten width
936  * @base: base of the number (octal, hex, ...)
937  * @precision: precision of a number
938  * @qualifier: qualifier of a number (long, size_t, ...)
939  */
940 static int format_decode(const char *fmt, struct printf_spec *spec)
941 {
942 	const char *start = fmt;
943 
944 	/* we finished early by reading the field width */
945 	if (spec->type == FORMAT_TYPE_WIDTH) {
946 		if (spec->field_width < 0) {
947 			spec->field_width = -spec->field_width;
948 			spec->flags |= LEFT;
949 		}
950 		spec->type = FORMAT_TYPE_NONE;
951 		goto precision;
952 	}
953 
954 	/* we finished early by reading the precision */
955 	if (spec->type == FORMAT_TYPE_PRECISION) {
956 		if (spec->precision < 0)
957 			spec->precision = 0;
958 
959 		spec->type = FORMAT_TYPE_NONE;
960 		goto qualifier;
961 	}
962 
963 	/* By default */
964 	spec->type = FORMAT_TYPE_NONE;
965 
966 	for (; *fmt ; ++fmt) {
967 		if (*fmt == '%')
968 			break;
969 	}
970 
971 	/* Return the current non-format string */
972 	if (fmt != start || !*fmt)
973 		return fmt - start;
974 
975 	/* Process flags */
976 	spec->flags = 0;
977 
978 	while (1) { /* this also skips first '%' */
979 		bool found = true;
980 
981 		++fmt;
982 
983 		switch (*fmt) {
984 		case '-': spec->flags |= LEFT;    break;
985 		case '+': spec->flags |= PLUS;    break;
986 		case ' ': spec->flags |= SPACE;   break;
987 		case '#': spec->flags |= SPECIAL; break;
988 		case '0': spec->flags |= ZEROPAD; break;
989 		default:  found = false;
990 		}
991 
992 		if (!found)
993 			break;
994 	}
995 
996 	/* get field width */
997 	spec->field_width = -1;
998 
999 	if (isdigit(*fmt))
1000 		spec->field_width = skip_atoi(&fmt);
1001 	else if (*fmt == '*') {
1002 		/* it's the next argument */
1003 		spec->type = FORMAT_TYPE_WIDTH;
1004 		return ++fmt - start;
1005 	}
1006 
1007 precision:
1008 	/* get the precision */
1009 	spec->precision = -1;
1010 	if (*fmt == '.') {
1011 		++fmt;
1012 		if (isdigit(*fmt)) {
1013 			spec->precision = skip_atoi(&fmt);
1014 			if (spec->precision < 0)
1015 				spec->precision = 0;
1016 		} else if (*fmt == '*') {
1017 			/* it's the next argument */
1018 			spec->type = FORMAT_TYPE_PRECISION;
1019 			return ++fmt - start;
1020 		}
1021 	}
1022 
1023 qualifier:
1024 	/* get the conversion qualifier */
1025 	spec->qualifier = -1;
1026 	if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
1027 	    *fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
1028 		spec->qualifier = *fmt++;
1029 		if (unlikely(spec->qualifier == *fmt)) {
1030 			if (spec->qualifier == 'l') {
1031 				spec->qualifier = 'L';
1032 				++fmt;
1033 			} else if (spec->qualifier == 'h') {
1034 				spec->qualifier = 'H';
1035 				++fmt;
1036 			}
1037 		}
1038 	}
1039 
1040 	/* default base */
1041 	spec->base = 10;
1042 	switch (*fmt) {
1043 	case 'c':
1044 		spec->type = FORMAT_TYPE_CHAR;
1045 		return ++fmt - start;
1046 
1047 	case 's':
1048 		spec->type = FORMAT_TYPE_STR;
1049 		return ++fmt - start;
1050 
1051 	case 'p':
1052 		spec->type = FORMAT_TYPE_PTR;
1053 		return fmt - start;
1054 		/* skip alnum */
1055 
1056 	case 'n':
1057 		spec->type = FORMAT_TYPE_NRCHARS;
1058 		return ++fmt - start;
1059 
1060 	case '%':
1061 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1062 		return ++fmt - start;
1063 
1064 	/* integer number formats - set up the flags and "break" */
1065 	case 'o':
1066 		spec->base = 8;
1067 		break;
1068 
1069 	case 'x':
1070 		spec->flags |= SMALL;
1071 
1072 	case 'X':
1073 		spec->base = 16;
1074 		break;
1075 
1076 	case 'd':
1077 	case 'i':
1078 		spec->flags |= SIGN;
1079 	case 'u':
1080 		break;
1081 
1082 	default:
1083 		spec->type = FORMAT_TYPE_INVALID;
1084 		return fmt - start;
1085 	}
1086 
1087 	if (spec->qualifier == 'L')
1088 		spec->type = FORMAT_TYPE_LONG_LONG;
1089 	else if (spec->qualifier == 'l') {
1090 		if (spec->flags & SIGN)
1091 			spec->type = FORMAT_TYPE_LONG;
1092 		else
1093 			spec->type = FORMAT_TYPE_ULONG;
1094 	} else if (spec->qualifier == 'Z' || spec->qualifier == 'z') {
1095 		spec->type = FORMAT_TYPE_SIZE_T;
1096 	} else if (spec->qualifier == 't') {
1097 		spec->type = FORMAT_TYPE_PTRDIFF;
1098 	} else if (spec->qualifier == 'H') {
1099 		if (spec->flags & SIGN)
1100 			spec->type = FORMAT_TYPE_BYTE;
1101 		else
1102 			spec->type = FORMAT_TYPE_UBYTE;
1103 	} else if (spec->qualifier == 'h') {
1104 		if (spec->flags & SIGN)
1105 			spec->type = FORMAT_TYPE_SHORT;
1106 		else
1107 			spec->type = FORMAT_TYPE_USHORT;
1108 	} else {
1109 		if (spec->flags & SIGN)
1110 			spec->type = FORMAT_TYPE_INT;
1111 		else
1112 			spec->type = FORMAT_TYPE_UINT;
1113 	}
1114 
1115 	return ++fmt - start;
1116 }
1117 
1118 /**
1119  * vsnprintf - Format a string and place it in a buffer
1120  * @buf: The buffer to place the result into
1121  * @size: The size of the buffer, including the trailing null space
1122  * @fmt: The format string to use
1123  * @args: Arguments for the format string
1124  *
1125  * This function follows C99 vsnprintf, but has some extensions:
1126  * %pS output the name of a text symbol with offset
1127  * %ps output the name of a text symbol without offset
1128  * %pF output the name of a function pointer with its offset
1129  * %pf output the name of a function pointer without its offset
1130  * %pR output the address range in a struct resource
1131  * %n is ignored
1132  *
1133  * The return value is the number of characters which would
1134  * be generated for the given input, excluding the trailing
1135  * '\0', as per ISO C99. If you want to have the exact
1136  * number of characters written into @buf as return value
1137  * (not including the trailing '\0'), use vscnprintf(). If the
1138  * return is greater than or equal to @size, the resulting
1139  * string is truncated.
1140  *
1141  * Call this function if you are already dealing with a va_list.
1142  * You probably want snprintf() instead.
1143  */
1144 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1145 {
1146 	unsigned long long num;
1147 	char *str, *end, c;
1148 	int read;
1149 	struct printf_spec spec = {0};
1150 
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;
1155 
1156 	str = buf;
1157 	end = buf + size;
1158 
1159 	/* Make sure end is always >= buf */
1160 	if (end < buf) {
1161 		end = ((void *)-1);
1162 		size = end - buf;
1163 	}
1164 
1165 	while (*fmt) {
1166 		const char *old_fmt = fmt;
1167 
1168 		read = format_decode(fmt, &spec);
1169 
1170 		fmt += read;
1171 
1172 		switch (spec.type) {
1173 		case FORMAT_TYPE_NONE: {
1174 			int copy = read;
1175 			if (str < end) {
1176 				if (copy > end - str)
1177 					copy = end - str;
1178 				memcpy(str, old_fmt, copy);
1179 			}
1180 			str += read;
1181 			break;
1182 		}
1183 
1184 		case FORMAT_TYPE_WIDTH:
1185 			spec.field_width = va_arg(args, int);
1186 			break;
1187 
1188 		case FORMAT_TYPE_PRECISION:
1189 			spec.precision = va_arg(args, int);
1190 			break;
1191 
1192 		case FORMAT_TYPE_CHAR:
1193 			if (!(spec.flags & LEFT)) {
1194 				while (--spec.field_width > 0) {
1195 					if (str < end)
1196 						*str = ' ';
1197 					++str;
1198 
1199 				}
1200 			}
1201 			c = (unsigned char) va_arg(args, int);
1202 			if (str < end)
1203 				*str = c;
1204 			++str;
1205 			while (--spec.field_width > 0) {
1206 				if (str < end)
1207 					*str = ' ';
1208 				++str;
1209 			}
1210 			break;
1211 
1212 		case FORMAT_TYPE_STR:
1213 			str = string(str, end, va_arg(args, char *), spec);
1214 			break;
1215 
1216 		case FORMAT_TYPE_PTR:
1217 			str = pointer(fmt+1, str, end, va_arg(args, void *),
1218 				      spec);
1219 			while (isalnum(*fmt))
1220 				fmt++;
1221 			break;
1222 
1223 		case FORMAT_TYPE_PERCENT_CHAR:
1224 			if (str < end)
1225 				*str = '%';
1226 			++str;
1227 			break;
1228 
1229 		case FORMAT_TYPE_INVALID:
1230 			if (str < end)
1231 				*str = '%';
1232 			++str;
1233 			break;
1234 
1235 		case FORMAT_TYPE_NRCHARS: {
1236 			int qualifier = spec.qualifier;
1237 
1238 			if (qualifier == 'l') {
1239 				long *ip = va_arg(args, long *);
1240 				*ip = (str - buf);
1241 			} else if (qualifier == 'Z' ||
1242 					qualifier == 'z') {
1243 				size_t *ip = va_arg(args, size_t *);
1244 				*ip = (str - buf);
1245 			} else {
1246 				int *ip = va_arg(args, int *);
1247 				*ip = (str - buf);
1248 			}
1249 			break;
1250 		}
1251 
1252 		default:
1253 			switch (spec.type) {
1254 			case FORMAT_TYPE_LONG_LONG:
1255 				num = va_arg(args, long long);
1256 				break;
1257 			case FORMAT_TYPE_ULONG:
1258 				num = va_arg(args, unsigned long);
1259 				break;
1260 			case FORMAT_TYPE_LONG:
1261 				num = va_arg(args, long);
1262 				break;
1263 			case FORMAT_TYPE_SIZE_T:
1264 				num = va_arg(args, size_t);
1265 				break;
1266 			case FORMAT_TYPE_PTRDIFF:
1267 				num = va_arg(args, ptrdiff_t);
1268 				break;
1269 			case FORMAT_TYPE_UBYTE:
1270 				num = (unsigned char) va_arg(args, int);
1271 				break;
1272 			case FORMAT_TYPE_BYTE:
1273 				num = (signed char) va_arg(args, int);
1274 				break;
1275 			case FORMAT_TYPE_USHORT:
1276 				num = (unsigned short) va_arg(args, int);
1277 				break;
1278 			case FORMAT_TYPE_SHORT:
1279 				num = (short) va_arg(args, int);
1280 				break;
1281 			case FORMAT_TYPE_INT:
1282 				num = (int) va_arg(args, int);
1283 				break;
1284 			default:
1285 				num = va_arg(args, unsigned int);
1286 			}
1287 
1288 			str = number(str, end, num, spec);
1289 		}
1290 	}
1291 
1292 	if (size > 0) {
1293 		if (str < end)
1294 			*str = '\0';
1295 		else
1296 			end[-1] = '\0';
1297 	}
1298 
1299 	/* the trailing null byte doesn't count towards the total */
1300 	return str-buf;
1301 
1302 }
1303 EXPORT_SYMBOL(vsnprintf);
1304 
1305 /**
1306  * vscnprintf - Format a string and place it in a buffer
1307  * @buf: The buffer to place the result into
1308  * @size: The size of the buffer, including the trailing null space
1309  * @fmt: The format string to use
1310  * @args: Arguments for the format string
1311  *
1312  * The return value is the number of characters which have been written into
1313  * the @buf not including the trailing '\0'. If @size is <= 0 the function
1314  * returns 0.
1315  *
1316  * Call this function if you are already dealing with a va_list.
1317  * You probably want scnprintf() instead.
1318  *
1319  * See the vsnprintf() documentation for format string extensions over C99.
1320  */
1321 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1322 {
1323 	int i;
1324 
1325 	i=vsnprintf(buf,size,fmt,args);
1326 	return (i >= size) ? (size - 1) : i;
1327 }
1328 EXPORT_SYMBOL(vscnprintf);
1329 
1330 /**
1331  * snprintf - Format a string and place it in a buffer
1332  * @buf: The buffer to place the result into
1333  * @size: The size of the buffer, including the trailing null space
1334  * @fmt: The format string to use
1335  * @...: Arguments for the format string
1336  *
1337  * The return value is the number of characters which would be
1338  * generated for the given input, excluding the trailing null,
1339  * as per ISO C99.  If the return is greater than or equal to
1340  * @size, the resulting string is truncated.
1341  *
1342  * See the vsnprintf() documentation for format string extensions over C99.
1343  */
1344 int snprintf(char * buf, size_t size, const char *fmt, ...)
1345 {
1346 	va_list args;
1347 	int i;
1348 
1349 	va_start(args, fmt);
1350 	i=vsnprintf(buf,size,fmt,args);
1351 	va_end(args);
1352 	return i;
1353 }
1354 EXPORT_SYMBOL(snprintf);
1355 
1356 /**
1357  * scnprintf - Format a string and place it in a buffer
1358  * @buf: The buffer to place the result into
1359  * @size: The size of the buffer, including the trailing null space
1360  * @fmt: The format string to use
1361  * @...: Arguments for the format string
1362  *
1363  * The return value is the number of characters written into @buf not including
1364  * the trailing '\0'. If @size is <= 0 the function returns 0.
1365  */
1366 
1367 int scnprintf(char * buf, size_t size, const char *fmt, ...)
1368 {
1369 	va_list args;
1370 	int i;
1371 
1372 	va_start(args, fmt);
1373 	i = vsnprintf(buf, size, fmt, args);
1374 	va_end(args);
1375 	return (i >= size) ? (size - 1) : i;
1376 }
1377 EXPORT_SYMBOL(scnprintf);
1378 
1379 /**
1380  * vsprintf - Format a string and place it in a buffer
1381  * @buf: The buffer to place the result into
1382  * @fmt: The format string to use
1383  * @args: Arguments for the format string
1384  *
1385  * The function returns the number of characters written
1386  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1387  * buffer overflows.
1388  *
1389  * Call this function if you are already dealing with a va_list.
1390  * You probably want sprintf() instead.
1391  *
1392  * See the vsnprintf() documentation for format string extensions over C99.
1393  */
1394 int vsprintf(char *buf, const char *fmt, va_list args)
1395 {
1396 	return vsnprintf(buf, INT_MAX, fmt, args);
1397 }
1398 EXPORT_SYMBOL(vsprintf);
1399 
1400 /**
1401  * sprintf - Format a string and place it in a buffer
1402  * @buf: The buffer to place the result into
1403  * @fmt: The format string to use
1404  * @...: Arguments for the format string
1405  *
1406  * The function returns the number of characters written
1407  * into @buf. Use snprintf() or scnprintf() in order to avoid
1408  * buffer overflows.
1409  *
1410  * See the vsnprintf() documentation for format string extensions over C99.
1411  */
1412 int sprintf(char * buf, const char *fmt, ...)
1413 {
1414 	va_list args;
1415 	int i;
1416 
1417 	va_start(args, fmt);
1418 	i=vsnprintf(buf, INT_MAX, fmt, args);
1419 	va_end(args);
1420 	return i;
1421 }
1422 EXPORT_SYMBOL(sprintf);
1423 
1424 #ifdef CONFIG_BINARY_PRINTF
1425 /*
1426  * bprintf service:
1427  * vbin_printf() - VA arguments to binary data
1428  * bstr_printf() - Binary data to text string
1429  */
1430 
1431 /**
1432  * vbin_printf - Parse a format string and place args' binary value in a buffer
1433  * @bin_buf: The buffer to place args' binary value
1434  * @size: The size of the buffer(by words(32bits), not characters)
1435  * @fmt: The format string to use
1436  * @args: Arguments for the format string
1437  *
1438  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1439  * is skiped.
1440  *
1441  * The return value is the number of words(32bits) which would be generated for
1442  * the given input.
1443  *
1444  * NOTE:
1445  * If the return value is greater than @size, the resulting bin_buf is NOT
1446  * valid for bstr_printf().
1447  */
1448 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1449 {
1450 	struct printf_spec spec = {0};
1451 	char *str, *end;
1452 	int read;
1453 
1454 	str = (char *)bin_buf;
1455 	end = (char *)(bin_buf + size);
1456 
1457 #define save_arg(type)							\
1458 do {									\
1459 	if (sizeof(type) == 8) {					\
1460 		unsigned long long value;				\
1461 		str = PTR_ALIGN(str, sizeof(u32));			\
1462 		value = va_arg(args, unsigned long long);		\
1463 		if (str + sizeof(type) <= end) {			\
1464 			*(u32 *)str = *(u32 *)&value;			\
1465 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
1466 		}							\
1467 	} else {							\
1468 		unsigned long value;					\
1469 		str = PTR_ALIGN(str, sizeof(type));			\
1470 		value = va_arg(args, int);				\
1471 		if (str + sizeof(type) <= end)				\
1472 			*(typeof(type) *)str = (type)value;		\
1473 	}								\
1474 	str += sizeof(type);						\
1475 } while (0)
1476 
1477 
1478 	while (*fmt) {
1479 		read = format_decode(fmt, &spec);
1480 
1481 		fmt += read;
1482 
1483 		switch (spec.type) {
1484 		case FORMAT_TYPE_NONE:
1485 			break;
1486 
1487 		case FORMAT_TYPE_WIDTH:
1488 		case FORMAT_TYPE_PRECISION:
1489 			save_arg(int);
1490 			break;
1491 
1492 		case FORMAT_TYPE_CHAR:
1493 			save_arg(char);
1494 			break;
1495 
1496 		case FORMAT_TYPE_STR: {
1497 			const char *save_str = va_arg(args, char *);
1498 			size_t len;
1499 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1500 					|| (unsigned long)save_str < PAGE_SIZE)
1501 				save_str = "<NULL>";
1502 			len = strlen(save_str);
1503 			if (str + len + 1 < end)
1504 				memcpy(str, save_str, len + 1);
1505 			str += len + 1;
1506 			break;
1507 		}
1508 
1509 		case FORMAT_TYPE_PTR:
1510 			save_arg(void *);
1511 			/* skip all alphanumeric pointer suffixes */
1512 			while (isalnum(*fmt))
1513 				fmt++;
1514 			break;
1515 
1516 		case FORMAT_TYPE_PERCENT_CHAR:
1517 			break;
1518 
1519 		case FORMAT_TYPE_INVALID:
1520 			break;
1521 
1522 		case FORMAT_TYPE_NRCHARS: {
1523 			/* skip %n 's argument */
1524 			int qualifier = spec.qualifier;
1525 			void *skip_arg;
1526 			if (qualifier == 'l')
1527 				skip_arg = va_arg(args, long *);
1528 			else if (qualifier == 'Z' || qualifier == 'z')
1529 				skip_arg = va_arg(args, size_t *);
1530 			else
1531 				skip_arg = va_arg(args, int *);
1532 			break;
1533 		}
1534 
1535 		default:
1536 			switch (spec.type) {
1537 
1538 			case FORMAT_TYPE_LONG_LONG:
1539 				save_arg(long long);
1540 				break;
1541 			case FORMAT_TYPE_ULONG:
1542 			case FORMAT_TYPE_LONG:
1543 				save_arg(unsigned long);
1544 				break;
1545 			case FORMAT_TYPE_SIZE_T:
1546 				save_arg(size_t);
1547 				break;
1548 			case FORMAT_TYPE_PTRDIFF:
1549 				save_arg(ptrdiff_t);
1550 				break;
1551 			case FORMAT_TYPE_UBYTE:
1552 			case FORMAT_TYPE_BYTE:
1553 				save_arg(char);
1554 				break;
1555 			case FORMAT_TYPE_USHORT:
1556 			case FORMAT_TYPE_SHORT:
1557 				save_arg(short);
1558 				break;
1559 			default:
1560 				save_arg(int);
1561 			}
1562 		}
1563 	}
1564 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1565 
1566 #undef save_arg
1567 }
1568 EXPORT_SYMBOL_GPL(vbin_printf);
1569 
1570 /**
1571  * bstr_printf - Format a string from binary arguments and place it in a buffer
1572  * @buf: The buffer to place the result into
1573  * @size: The size of the buffer, including the trailing null space
1574  * @fmt: The format string to use
1575  * @bin_buf: Binary arguments for the format string
1576  *
1577  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1578  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1579  * a binary buffer that generated by vbin_printf.
1580  *
1581  * The format follows C99 vsnprintf, but has some extensions:
1582  *  see vsnprintf comment for details.
1583  *
1584  * The return value is the number of characters which would
1585  * be generated for the given input, excluding the trailing
1586  * '\0', as per ISO C99. If you want to have the exact
1587  * number of characters written into @buf as return value
1588  * (not including the trailing '\0'), use vscnprintf(). If the
1589  * return is greater than or equal to @size, the resulting
1590  * string is truncated.
1591  */
1592 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1593 {
1594 	unsigned long long num;
1595 	char *str, *end, c;
1596 	const char *args = (const char *)bin_buf;
1597 
1598 	struct printf_spec spec = {0};
1599 
1600 	if (WARN_ON_ONCE((int) size < 0))
1601 		return 0;
1602 
1603 	str = buf;
1604 	end = buf + size;
1605 
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;				\
1616 	}								\
1617 	args += sizeof(type);						\
1618 	value;								\
1619 })
1620 
1621 	/* Make sure end is always >= buf */
1622 	if (end < buf) {
1623 		end = ((void *)-1);
1624 		size = end - buf;
1625 	}
1626 
1627 	while (*fmt) {
1628 		int read;
1629 		const char *old_fmt = fmt;
1630 
1631 		read = format_decode(fmt, &spec);
1632 
1633 		fmt += read;
1634 
1635 		switch (spec.type) {
1636 		case FORMAT_TYPE_NONE: {
1637 			int copy = read;
1638 			if (str < end) {
1639 				if (copy > end - str)
1640 					copy = end - str;
1641 				memcpy(str, old_fmt, copy);
1642 			}
1643 			str += read;
1644 			break;
1645 		}
1646 
1647 		case FORMAT_TYPE_WIDTH:
1648 			spec.field_width = get_arg(int);
1649 			break;
1650 
1651 		case FORMAT_TYPE_PRECISION:
1652 			spec.precision = get_arg(int);
1653 			break;
1654 
1655 		case FORMAT_TYPE_CHAR:
1656 			if (!(spec.flags & LEFT)) {
1657 				while (--spec.field_width > 0) {
1658 					if (str < end)
1659 						*str = ' ';
1660 					++str;
1661 				}
1662 			}
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;
1671 			}
1672 			break;
1673 
1674 		case FORMAT_TYPE_STR: {
1675 			const char *str_arg = args;
1676 			size_t len = strlen(str_arg);
1677 			args += len + 1;
1678 			str = string(str, end, (char *)str_arg, spec);
1679 			break;
1680 		}
1681 
1682 		case FORMAT_TYPE_PTR:
1683 			str = pointer(fmt+1, str, end, get_arg(void *), spec);
1684 			while (isalnum(*fmt))
1685 				fmt++;
1686 			break;
1687 
1688 		case FORMAT_TYPE_PERCENT_CHAR:
1689 			if (str < end)
1690 				*str = '%';
1691 			++str;
1692 			break;
1693 
1694 		case FORMAT_TYPE_INVALID:
1695 			if (str < end)
1696 				*str = '%';
1697 			++str;
1698 			break;
1699 
1700 		case FORMAT_TYPE_NRCHARS:
1701 			/* skip */
1702 			break;
1703 
1704 		default:
1705 			switch (spec.type) {
1706 
1707 			case FORMAT_TYPE_LONG_LONG:
1708 				num = get_arg(long long);
1709 				break;
1710 			case FORMAT_TYPE_ULONG:
1711 				num = get_arg(unsigned long);
1712 				break;
1713 			case FORMAT_TYPE_LONG:
1714 				num = get_arg(unsigned long);
1715 				break;
1716 			case FORMAT_TYPE_SIZE_T:
1717 				num = get_arg(size_t);
1718 				break;
1719 			case FORMAT_TYPE_PTRDIFF:
1720 				num = get_arg(ptrdiff_t);
1721 				break;
1722 			case FORMAT_TYPE_UBYTE:
1723 				num = get_arg(unsigned char);
1724 				break;
1725 			case FORMAT_TYPE_BYTE:
1726 				num = get_arg(signed char);
1727 				break;
1728 			case FORMAT_TYPE_USHORT:
1729 				num = get_arg(unsigned short);
1730 				break;
1731 			case FORMAT_TYPE_SHORT:
1732 				num = get_arg(short);
1733 				break;
1734 			case FORMAT_TYPE_UINT:
1735 				num = get_arg(unsigned int);
1736 				break;
1737 			default:
1738 				num = get_arg(int);
1739 			}
1740 
1741 			str = number(str, end, num, spec);
1742 		}
1743 	}
1744 
1745 	if (size > 0) {
1746 		if (str < end)
1747 			*str = '\0';
1748 		else
1749 			end[-1] = '\0';
1750 	}
1751 
1752 #undef get_arg
1753 
1754 	/* the trailing null byte doesn't count towards the total */
1755 	return str - buf;
1756 }
1757 EXPORT_SYMBOL_GPL(bstr_printf);
1758 
1759 /**
1760  * bprintf - Parse a format string and place args' binary value in a buffer
1761  * @bin_buf: The buffer to place args' binary value
1762  * @size: The size of the buffer(by words(32bits), not characters)
1763  * @fmt: The format string to use
1764  * @...: Arguments for the format string
1765  *
1766  * The function returns the number of words(u32) written
1767  * into @bin_buf.
1768  */
1769 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1770 {
1771 	va_list args;
1772 	int ret;
1773 
1774 	va_start(args, fmt);
1775 	ret = vbin_printf(bin_buf, size, fmt, args);
1776 	va_end(args);
1777 	return ret;
1778 }
1779 EXPORT_SYMBOL_GPL(bprintf);
1780 
1781 #endif /* CONFIG_BINARY_PRINTF */
1782 
1783 /**
1784  * vsscanf - Unformat a buffer into a list of arguments
1785  * @buf:	input buffer
1786  * @fmt:	format of buffer
1787  * @args:	arguments
1788  */
1789 int vsscanf(const char * buf, const char * fmt, va_list args)
1790 {
1791 	const char *str = buf;
1792 	char *next;
1793 	char digit;
1794 	int num = 0;
1795 	int qualifier;
1796 	int base;
1797 	int field_width;
1798 	int is_sign = 0;
1799 
1800 	while(*fmt && *str) {
1801 		/* skip any white space in format */
1802 		/* white space in format matchs any amount of
1803 		 * white space, including none, in the input.
1804 		 */
1805 		if (isspace(*fmt)) {
1806 			while (isspace(*fmt))
1807 				++fmt;
1808 			while (isspace(*str))
1809 				++str;
1810 		}
1811 
1812 		/* anything that is not a conversion must match exactly */
1813 		if (*fmt != '%' && *fmt) {
1814 			if (*fmt++ != *str++)
1815 				break;
1816 			continue;
1817 		}
1818 
1819 		if (!*fmt)
1820 			break;
1821 		++fmt;
1822 
1823 		/* skip this conversion.
1824 		 * advance both strings to next white space
1825 		 */
1826 		if (*fmt == '*') {
1827 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
1828 				fmt++;
1829 			while (!isspace(*str) && *str)
1830 				str++;
1831 			continue;
1832 		}
1833 
1834 		/* get field width */
1835 		field_width = -1;
1836 		if (isdigit(*fmt))
1837 			field_width = skip_atoi(&fmt);
1838 
1839 		/* get conversion qualifier */
1840 		qualifier = -1;
1841 		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
1842 		    *fmt == 'Z' || *fmt == 'z') {
1843 			qualifier = *fmt++;
1844 			if (unlikely(qualifier == *fmt)) {
1845 				if (qualifier == 'h') {
1846 					qualifier = 'H';
1847 					fmt++;
1848 				} else if (qualifier == 'l') {
1849 					qualifier = 'L';
1850 					fmt++;
1851 				}
1852 			}
1853 		}
1854 		base = 10;
1855 		is_sign = 0;
1856 
1857 		if (!*fmt || !*str)
1858 			break;
1859 
1860 		switch(*fmt++) {
1861 		case 'c':
1862 		{
1863 			char *s = (char *) va_arg(args,char*);
1864 			if (field_width == -1)
1865 				field_width = 1;
1866 			do {
1867 				*s++ = *str++;
1868 			} while (--field_width > 0 && *str);
1869 			num++;
1870 		}
1871 		continue;
1872 		case 's':
1873 		{
1874 			char *s = (char *) va_arg(args, char *);
1875 			if(field_width == -1)
1876 				field_width = INT_MAX;
1877 			/* first, skip leading white space in buffer */
1878 			while (isspace(*str))
1879 				str++;
1880 
1881 			/* now copy until next white space */
1882 			while (*str && !isspace(*str) && field_width--) {
1883 				*s++ = *str++;
1884 			}
1885 			*s = '\0';
1886 			num++;
1887 		}
1888 		continue;
1889 		case 'n':
1890 			/* return number of characters read so far */
1891 		{
1892 			int *i = (int *)va_arg(args,int*);
1893 			*i = str - buf;
1894 		}
1895 		continue;
1896 		case 'o':
1897 			base = 8;
1898 			break;
1899 		case 'x':
1900 		case 'X':
1901 			base = 16;
1902 			break;
1903 		case 'i':
1904                         base = 0;
1905 		case 'd':
1906 			is_sign = 1;
1907 		case 'u':
1908 			break;
1909 		case '%':
1910 			/* looking for '%' in str */
1911 			if (*str++ != '%')
1912 				return num;
1913 			continue;
1914 		default:
1915 			/* invalid format; stop here */
1916 			return num;
1917 		}
1918 
1919 		/* have some sort of integer conversion.
1920 		 * first, skip white space in buffer.
1921 		 */
1922 		while (isspace(*str))
1923 			str++;
1924 
1925 		digit = *str;
1926 		if (is_sign && digit == '-')
1927 			digit = *(str + 1);
1928 
1929 		if (!digit
1930                     || (base == 16 && !isxdigit(digit))
1931                     || (base == 10 && !isdigit(digit))
1932                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1933                     || (base == 0 && !isdigit(digit)))
1934 				break;
1935 
1936 		switch(qualifier) {
1937 		case 'H':	/* that's 'hh' in format */
1938 			if (is_sign) {
1939 				signed char *s = (signed char *) va_arg(args,signed char *);
1940 				*s = (signed char) simple_strtol(str,&next,base);
1941 			} else {
1942 				unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1943 				*s = (unsigned char) simple_strtoul(str, &next, base);
1944 			}
1945 			break;
1946 		case 'h':
1947 			if (is_sign) {
1948 				short *s = (short *) va_arg(args,short *);
1949 				*s = (short) simple_strtol(str,&next,base);
1950 			} else {
1951 				unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1952 				*s = (unsigned short) simple_strtoul(str, &next, base);
1953 			}
1954 			break;
1955 		case 'l':
1956 			if (is_sign) {
1957 				long *l = (long *) va_arg(args,long *);
1958 				*l = simple_strtol(str,&next,base);
1959 			} else {
1960 				unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1961 				*l = simple_strtoul(str,&next,base);
1962 			}
1963 			break;
1964 		case 'L':
1965 			if (is_sign) {
1966 				long long *l = (long long*) va_arg(args,long long *);
1967 				*l = simple_strtoll(str,&next,base);
1968 			} else {
1969 				unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1970 				*l = simple_strtoull(str,&next,base);
1971 			}
1972 			break;
1973 		case 'Z':
1974 		case 'z':
1975 		{
1976 			size_t *s = (size_t*) va_arg(args,size_t*);
1977 			*s = (size_t) simple_strtoul(str,&next,base);
1978 		}
1979 		break;
1980 		default:
1981 			if (is_sign) {
1982 				int *i = (int *) va_arg(args, int*);
1983 				*i = (int) simple_strtol(str,&next,base);
1984 			} else {
1985 				unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1986 				*i = (unsigned int) simple_strtoul(str,&next,base);
1987 			}
1988 			break;
1989 		}
1990 		num++;
1991 
1992 		if (!next)
1993 			break;
1994 		str = next;
1995 	}
1996 
1997 	/*
1998 	 * Now we've come all the way through so either the input string or the
1999 	 * format ended. In the former case, there can be a %n at the current
2000 	 * position in the format that needs to be filled.
2001 	 */
2002 	if (*fmt == '%' && *(fmt + 1) == 'n') {
2003 		int *p = (int *)va_arg(args, int *);
2004 		*p = str - buf;
2005 	}
2006 
2007 	return num;
2008 }
2009 EXPORT_SYMBOL(vsscanf);
2010 
2011 /**
2012  * sscanf - Unformat a buffer into a list of arguments
2013  * @buf:	input buffer
2014  * @fmt:	formatting of buffer
2015  * @...:	resulting arguments
2016  */
2017 int sscanf(const char * buf, const char * fmt, ...)
2018 {
2019 	va_list args;
2020 	int i;
2021 
2022 	va_start(args,fmt);
2023 	i = vsscanf(buf,fmt,args);
2024 	va_end(args);
2025 	return i;
2026 }
2027 EXPORT_SYMBOL(sscanf);
2028