xref: /openbmc/linux/lib/vsprintf.c (revision b6dcefde)
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_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  */
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  */
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  */
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  */
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 
122 /**
123  * strict_strtoul - convert a string to an unsigned long strictly
124  * @cp: The string to be converted
125  * @base: The number base to use
126  * @res: The converted result value
127  *
128  * strict_strtoul converts a string to an unsigned long only if the
129  * string is really an unsigned long string, any string containing
130  * any invalid char at the tail will be rejected and -EINVAL is returned,
131  * only a newline char at the tail is acceptible because people generally
132  * change a module parameter in the following way:
133  *
134  * 	echo 1024 > /sys/module/e1000/parameters/copybreak
135  *
136  * echo will append a newline to the tail.
137  *
138  * It returns 0 if conversion is successful and *res is set to the converted
139  * value, otherwise it returns -EINVAL and *res is set to 0.
140  *
141  * simple_strtoul just ignores the successive invalid characters and
142  * return the converted value of prefix part of the string.
143  */
144 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
145 {
146 	char *tail;
147 	unsigned long val;
148 	size_t len;
149 
150 	*res = 0;
151 	len = strlen(cp);
152 	if (len == 0)
153 		return -EINVAL;
154 
155 	val = simple_strtoul(cp, &tail, base);
156 	if (tail == cp)
157 		return -EINVAL;
158 
159 	if ((*tail == '\0') ||
160 		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
161 		*res = val;
162 		return 0;
163 	}
164 
165 	return -EINVAL;
166 }
167 EXPORT_SYMBOL(strict_strtoul);
168 
169 /**
170  * strict_strtol - convert a string to a long strictly
171  * @cp: The string to be converted
172  * @base: The number base to use
173  * @res: The converted result value
174  *
175  * strict_strtol is similiar to strict_strtoul, but it allows the first
176  * character of a string is '-'.
177  *
178  * It returns 0 if conversion is successful and *res is set to the converted
179  * value, otherwise it returns -EINVAL and *res is set to 0.
180  */
181 int strict_strtol(const char *cp, unsigned int base, long *res)
182 {
183 	int ret;
184 	if (*cp == '-') {
185 		ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
186 		if (!ret)
187 			*res = -(*res);
188 	} else {
189 		ret = strict_strtoul(cp, base, (unsigned long *)res);
190 	}
191 
192 	return ret;
193 }
194 EXPORT_SYMBOL(strict_strtol);
195 
196 /**
197  * strict_strtoull - convert a string to an unsigned long long strictly
198  * @cp: The string to be converted
199  * @base: The number base to use
200  * @res: The converted result value
201  *
202  * strict_strtoull converts a string to an unsigned long long only if the
203  * string is really an unsigned long long string, any string containing
204  * any invalid char at the tail will be rejected and -EINVAL is returned,
205  * only a newline char at the tail is acceptible because people generally
206  * change a module parameter in the following way:
207  *
208  * 	echo 1024 > /sys/module/e1000/parameters/copybreak
209  *
210  * echo will append a newline to the tail of the string.
211  *
212  * It returns 0 if conversion is successful and *res is set to the converted
213  * value, otherwise it returns -EINVAL and *res is set to 0.
214  *
215  * simple_strtoull just ignores the successive invalid characters and
216  * return the converted value of prefix part of the string.
217  */
218 int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
219 {
220 	char *tail;
221 	unsigned long long val;
222 	size_t len;
223 
224 	*res = 0;
225 	len = strlen(cp);
226 	if (len == 0)
227 		return -EINVAL;
228 
229 	val = simple_strtoull(cp, &tail, base);
230 	if (tail == cp)
231 		return -EINVAL;
232 	if ((*tail == '\0') ||
233 		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
234 		*res = val;
235 		return 0;
236 	}
237 
238 	return -EINVAL;
239 }
240 EXPORT_SYMBOL(strict_strtoull);
241 
242 /**
243  * strict_strtoll - convert a string to a long long strictly
244  * @cp: The string to be converted
245  * @base: The number base to use
246  * @res: The converted result value
247  *
248  * strict_strtoll is similiar to strict_strtoull, but it allows the first
249  * character of a string is '-'.
250  *
251  * It returns 0 if conversion is successful and *res is set to the converted
252  * value, otherwise it returns -EINVAL and *res is set to 0.
253  */
254 int strict_strtoll(const char *cp, unsigned int base, long long *res)
255 {
256 	int ret;
257 	if (*cp == '-') {
258 		ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
259 		if (!ret)
260 			*res = -(*res);
261 	} else {
262 		ret = strict_strtoull(cp, base, (unsigned long long *)res);
263 	}
264 
265 	return ret;
266 }
267 EXPORT_SYMBOL(strict_strtoll);
268 
269 static int skip_atoi(const char **s)
270 {
271 	int i = 0;
272 
273 	while (isdigit(**s))
274 		i = i*10 + *((*s)++) - '0';
275 
276 	return i;
277 }
278 
279 /* Decimal conversion is by far the most typical, and is used
280  * for /proc and /sys data. This directly impacts e.g. top performance
281  * with many processes running. We optimize it for speed
282  * using code from
283  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
284  * (with permission from the author, Douglas W. Jones). */
285 
286 /* Formats correctly any integer in [0,99999].
287  * Outputs from one to five digits depending on input.
288  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
289 static char *put_dec_trunc(char *buf, unsigned q)
290 {
291 	unsigned d3, d2, d1, d0;
292 	d1 = (q>>4) & 0xf;
293 	d2 = (q>>8) & 0xf;
294 	d3 = (q>>12);
295 
296 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
297 	q = (d0 * 0xcd) >> 11;
298 	d0 = d0 - 10*q;
299 	*buf++ = d0 + '0'; /* least significant digit */
300 	d1 = q + 9*d3 + 5*d2 + d1;
301 	if (d1 != 0) {
302 		q = (d1 * 0xcd) >> 11;
303 		d1 = d1 - 10*q;
304 		*buf++ = d1 + '0'; /* next digit */
305 
306 		d2 = q + 2*d2;
307 		if ((d2 != 0) || (d3 != 0)) {
308 			q = (d2 * 0xd) >> 7;
309 			d2 = d2 - 10*q;
310 			*buf++ = d2 + '0'; /* next digit */
311 
312 			d3 = q + 4*d3;
313 			if (d3 != 0) {
314 				q = (d3 * 0xcd) >> 11;
315 				d3 = d3 - 10*q;
316 				*buf++ = d3 + '0';  /* next digit */
317 				if (q != 0)
318 					*buf++ = q + '0'; /* most sign. digit */
319 			}
320 		}
321 	}
322 
323 	return buf;
324 }
325 /* Same with if's removed. Always emits five digits */
326 static char *put_dec_full(char *buf, unsigned q)
327 {
328 	/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
329 	/* but anyway, gcc produces better code with full-sized ints */
330 	unsigned d3, d2, d1, d0;
331 	d1 = (q>>4) & 0xf;
332 	d2 = (q>>8) & 0xf;
333 	d3 = (q>>12);
334 
335 	/*
336 	 * Possible ways to approx. divide by 10
337 	 * gcc -O2 replaces multiply with shifts and adds
338 	 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
339 	 * (x * 0x67) >> 10:  1100111
340 	 * (x * 0x34) >> 9:    110100 - same
341 	 * (x * 0x1a) >> 8:     11010 - same
342 	 * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
343 	 */
344 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
345 	q = (d0 * 0xcd) >> 11;
346 	d0 = d0 - 10*q;
347 	*buf++ = d0 + '0';
348 	d1 = q + 9*d3 + 5*d2 + d1;
349 		q = (d1 * 0xcd) >> 11;
350 		d1 = d1 - 10*q;
351 		*buf++ = d1 + '0';
352 
353 		d2 = q + 2*d2;
354 			q = (d2 * 0xd) >> 7;
355 			d2 = d2 - 10*q;
356 			*buf++ = d2 + '0';
357 
358 			d3 = q + 4*d3;
359 				q = (d3 * 0xcd) >> 11; /* - shorter code */
360 				/* q = (d3 * 0x67) >> 10; - would also work */
361 				d3 = d3 - 10*q;
362 				*buf++ = d3 + '0';
363 					*buf++ = q + '0';
364 
365 	return buf;
366 }
367 /* No inlining helps gcc to use registers better */
368 static noinline char *put_dec(char *buf, unsigned long long num)
369 {
370 	while (1) {
371 		unsigned rem;
372 		if (num < 100000)
373 			return put_dec_trunc(buf, num);
374 		rem = do_div(num, 100000);
375 		buf = put_dec_full(buf, rem);
376 	}
377 }
378 
379 #define ZEROPAD	1		/* pad with zero */
380 #define SIGN	2		/* unsigned/signed long */
381 #define PLUS	4		/* show plus */
382 #define SPACE	8		/* space if plus */
383 #define LEFT	16		/* left justified */
384 #define SMALL	32		/* Must be 32 == 0x20 */
385 #define SPECIAL	64		/* 0x */
386 
387 enum format_type {
388 	FORMAT_TYPE_NONE, /* Just a string part */
389 	FORMAT_TYPE_WIDTH,
390 	FORMAT_TYPE_PRECISION,
391 	FORMAT_TYPE_CHAR,
392 	FORMAT_TYPE_STR,
393 	FORMAT_TYPE_PTR,
394 	FORMAT_TYPE_PERCENT_CHAR,
395 	FORMAT_TYPE_INVALID,
396 	FORMAT_TYPE_LONG_LONG,
397 	FORMAT_TYPE_ULONG,
398 	FORMAT_TYPE_LONG,
399 	FORMAT_TYPE_UBYTE,
400 	FORMAT_TYPE_BYTE,
401 	FORMAT_TYPE_USHORT,
402 	FORMAT_TYPE_SHORT,
403 	FORMAT_TYPE_UINT,
404 	FORMAT_TYPE_INT,
405 	FORMAT_TYPE_NRCHARS,
406 	FORMAT_TYPE_SIZE_T,
407 	FORMAT_TYPE_PTRDIFF
408 };
409 
410 struct printf_spec {
411 	enum format_type	type;
412 	int			flags;		/* flags to number() */
413 	int			field_width;	/* width of output field */
414 	int			base;
415 	int			precision;	/* # of digits/chars */
416 	int			qualifier;
417 };
418 
419 static char *number(char *buf, char *end, unsigned long long num,
420 			struct printf_spec spec)
421 {
422 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
423 	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
424 
425 	char tmp[66];
426 	char sign;
427 	char locase;
428 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
429 	int i;
430 
431 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
432 	 * produces same digits or (maybe lowercased) letters */
433 	locase = (spec.flags & SMALL);
434 	if (spec.flags & LEFT)
435 		spec.flags &= ~ZEROPAD;
436 	sign = 0;
437 	if (spec.flags & SIGN) {
438 		if ((signed long long)num < 0) {
439 			sign = '-';
440 			num = -(signed long long)num;
441 			spec.field_width--;
442 		} else if (spec.flags & PLUS) {
443 			sign = '+';
444 			spec.field_width--;
445 		} else if (spec.flags & SPACE) {
446 			sign = ' ';
447 			spec.field_width--;
448 		}
449 	}
450 	if (need_pfx) {
451 		spec.field_width--;
452 		if (spec.base == 16)
453 			spec.field_width--;
454 	}
455 
456 	/* generate full string in tmp[], in reverse order */
457 	i = 0;
458 	if (num == 0)
459 		tmp[i++] = '0';
460 	/* Generic code, for any base:
461 	else do {
462 		tmp[i++] = (digits[do_div(num,base)] | locase);
463 	} while (num != 0);
464 	*/
465 	else if (spec.base != 10) { /* 8 or 16 */
466 		int mask = spec.base - 1;
467 		int shift = 3;
468 
469 		if (spec.base == 16)
470 			shift = 4;
471 		do {
472 			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
473 			num >>= shift;
474 		} while (num);
475 	} else { /* base 10 */
476 		i = put_dec(tmp, num) - tmp;
477 	}
478 
479 	/* printing 100 using %2d gives "100", not "00" */
480 	if (i > spec.precision)
481 		spec.precision = i;
482 	/* leading space padding */
483 	spec.field_width -= spec.precision;
484 	if (!(spec.flags & (ZEROPAD+LEFT))) {
485 		while (--spec.field_width >= 0) {
486 			if (buf < end)
487 				*buf = ' ';
488 			++buf;
489 		}
490 	}
491 	/* sign */
492 	if (sign) {
493 		if (buf < end)
494 			*buf = sign;
495 		++buf;
496 	}
497 	/* "0x" / "0" prefix */
498 	if (need_pfx) {
499 		if (buf < end)
500 			*buf = '0';
501 		++buf;
502 		if (spec.base == 16) {
503 			if (buf < end)
504 				*buf = ('X' | locase);
505 			++buf;
506 		}
507 	}
508 	/* zero or space padding */
509 	if (!(spec.flags & LEFT)) {
510 		char c = (spec.flags & ZEROPAD) ? '0' : ' ';
511 		while (--spec.field_width >= 0) {
512 			if (buf < end)
513 				*buf = c;
514 			++buf;
515 		}
516 	}
517 	/* hmm even more zero padding? */
518 	while (i <= --spec.precision) {
519 		if (buf < end)
520 			*buf = '0';
521 		++buf;
522 	}
523 	/* actual digits of result */
524 	while (--i >= 0) {
525 		if (buf < end)
526 			*buf = tmp[i];
527 		++buf;
528 	}
529 	/* trailing space padding */
530 	while (--spec.field_width >= 0) {
531 		if (buf < end)
532 			*buf = ' ';
533 		++buf;
534 	}
535 
536 	return buf;
537 }
538 
539 static char *string(char *buf, char *end, const char *s, struct printf_spec spec)
540 {
541 	int len, i;
542 
543 	if ((unsigned long)s < PAGE_SIZE)
544 		s = "(null)";
545 
546 	len = strnlen(s, spec.precision);
547 
548 	if (!(spec.flags & LEFT)) {
549 		while (len < spec.field_width--) {
550 			if (buf < end)
551 				*buf = ' ';
552 			++buf;
553 		}
554 	}
555 	for (i = 0; i < len; ++i) {
556 		if (buf < end)
557 			*buf = *s;
558 		++buf; ++s;
559 	}
560 	while (len < spec.field_width--) {
561 		if (buf < end)
562 			*buf = ' ';
563 		++buf;
564 	}
565 
566 	return buf;
567 }
568 
569 static char *symbol_string(char *buf, char *end, void *ptr,
570 				struct printf_spec spec, char ext)
571 {
572 	unsigned long value = (unsigned long) ptr;
573 #ifdef CONFIG_KALLSYMS
574 	char sym[KSYM_SYMBOL_LEN];
575 	if (ext != 'f' && ext != 's')
576 		sprint_symbol(sym, value);
577 	else
578 		kallsyms_lookup(value, NULL, NULL, NULL, sym);
579 
580 	return string(buf, end, sym, spec);
581 #else
582 	spec.field_width = 2 * sizeof(void *);
583 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
584 	spec.base = 16;
585 
586 	return number(buf, end, value, spec);
587 #endif
588 }
589 
590 static char *resource_string(char *buf, char *end, struct resource *res,
591 				struct printf_spec spec, const char *fmt)
592 {
593 #ifndef IO_RSRC_PRINTK_SIZE
594 #define IO_RSRC_PRINTK_SIZE	6
595 #endif
596 
597 #ifndef MEM_RSRC_PRINTK_SIZE
598 #define MEM_RSRC_PRINTK_SIZE	10
599 #endif
600 	struct printf_spec hex_spec = {
601 		.base = 16,
602 		.precision = -1,
603 		.flags = SPECIAL | SMALL | ZEROPAD,
604 	};
605 	struct printf_spec dec_spec = {
606 		.base = 10,
607 		.precision = -1,
608 		.flags = 0,
609 	};
610 	struct printf_spec str_spec = {
611 		.field_width = -1,
612 		.precision = 10,
613 		.flags = LEFT,
614 	};
615 	struct printf_spec flag_spec = {
616 		.base = 16,
617 		.precision = -1,
618 		.flags = SPECIAL | SMALL,
619 	};
620 
621 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
622 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
623 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
624 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
625 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref disabled]")
626 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
627 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
628 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
629 
630 	char *p = sym, *pend = sym + sizeof(sym);
631 	int size = -1, addr = 0;
632 	int decode = (fmt[0] == 'R') ? 1 : 0;
633 
634 	if (res->flags & IORESOURCE_IO) {
635 		size = IO_RSRC_PRINTK_SIZE;
636 		addr = 1;
637 	} else if (res->flags & IORESOURCE_MEM) {
638 		size = MEM_RSRC_PRINTK_SIZE;
639 		addr = 1;
640 	}
641 
642 	*p++ = '[';
643 	if (res->flags & IORESOURCE_IO)
644 		p = string(p, pend, "io  ", str_spec);
645 	else if (res->flags & IORESOURCE_MEM)
646 		p = string(p, pend, "mem ", str_spec);
647 	else if (res->flags & IORESOURCE_IRQ)
648 		p = string(p, pend, "irq ", str_spec);
649 	else if (res->flags & IORESOURCE_DMA)
650 		p = string(p, pend, "dma ", str_spec);
651 	else {
652 		p = string(p, pend, "??? ", str_spec);
653 		decode = 0;
654 	}
655 	hex_spec.field_width = size;
656 	p = number(p, pend, res->start, addr ? hex_spec : dec_spec);
657 	if (res->start != res->end) {
658 		*p++ = '-';
659 		p = number(p, pend, res->end, addr ? hex_spec : dec_spec);
660 	}
661 	if (decode) {
662 		if (res->flags & IORESOURCE_MEM_64)
663 			p = string(p, pend, " 64bit", str_spec);
664 		if (res->flags & IORESOURCE_PREFETCH)
665 			p = string(p, pend, " pref", str_spec);
666 		if (res->flags & IORESOURCE_DISABLED)
667 			p = string(p, pend, " disabled", str_spec);
668 	} else {
669 		p = string(p, pend, " flags ", str_spec);
670 		p = number(p, pend, res->flags, flag_spec);
671 	}
672 	*p++ = ']';
673 	*p = '\0';
674 
675 	return string(buf, end, sym, spec);
676 }
677 
678 static char *mac_address_string(char *buf, char *end, u8 *addr,
679 				struct printf_spec spec, const char *fmt)
680 {
681 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
682 	char *p = mac_addr;
683 	int i;
684 
685 	for (i = 0; i < 6; i++) {
686 		p = pack_hex_byte(p, addr[i]);
687 		if (fmt[0] == 'M' && i != 5)
688 			*p++ = ':';
689 	}
690 	*p = '\0';
691 
692 	return string(buf, end, mac_addr, spec);
693 }
694 
695 static char *ip4_string(char *p, const u8 *addr, bool leading_zeros)
696 {
697 	int i;
698 
699 	for (i = 0; i < 4; i++) {
700 		char temp[3];	/* hold each IP quad in reverse order */
701 		int digits = put_dec_trunc(temp, addr[i]) - temp;
702 		if (leading_zeros) {
703 			if (digits < 3)
704 				*p++ = '0';
705 			if (digits < 2)
706 				*p++ = '0';
707 		}
708 		/* reverse the digits in the quad */
709 		while (digits--)
710 			*p++ = temp[digits];
711 		if (i < 3)
712 			*p++ = '.';
713 	}
714 	*p = '\0';
715 
716 	return p;
717 }
718 
719 static char *ip6_compressed_string(char *p, const char *addr)
720 {
721 	int i, j, range;
722 	unsigned char zerolength[8];
723 	int longest = 1;
724 	int colonpos = -1;
725 	u16 word;
726 	u8 hi, lo;
727 	bool needcolon = false;
728 	bool useIPv4;
729 	struct in6_addr in6;
730 
731 	memcpy(&in6, addr, sizeof(struct in6_addr));
732 
733 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
734 
735 	memset(zerolength, 0, sizeof(zerolength));
736 
737 	if (useIPv4)
738 		range = 6;
739 	else
740 		range = 8;
741 
742 	/* find position of longest 0 run */
743 	for (i = 0; i < range; i++) {
744 		for (j = i; j < range; j++) {
745 			if (in6.s6_addr16[j] != 0)
746 				break;
747 			zerolength[i]++;
748 		}
749 	}
750 	for (i = 0; i < range; i++) {
751 		if (zerolength[i] > longest) {
752 			longest = zerolength[i];
753 			colonpos = i;
754 		}
755 	}
756 
757 	/* emit address */
758 	for (i = 0; i < range; i++) {
759 		if (i == colonpos) {
760 			if (needcolon || i == 0)
761 				*p++ = ':';
762 			*p++ = ':';
763 			needcolon = false;
764 			i += longest - 1;
765 			continue;
766 		}
767 		if (needcolon) {
768 			*p++ = ':';
769 			needcolon = false;
770 		}
771 		/* hex u16 without leading 0s */
772 		word = ntohs(in6.s6_addr16[i]);
773 		hi = word >> 8;
774 		lo = word & 0xff;
775 		if (hi) {
776 			if (hi > 0x0f)
777 				p = pack_hex_byte(p, hi);
778 			else
779 				*p++ = hex_asc_lo(hi);
780 			p = pack_hex_byte(p, lo);
781 		}
782 		else if (lo > 0x0f)
783 			p = pack_hex_byte(p, lo);
784 		else
785 			*p++ = hex_asc_lo(lo);
786 		needcolon = true;
787 	}
788 
789 	if (useIPv4) {
790 		if (needcolon)
791 			*p++ = ':';
792 		p = ip4_string(p, &in6.s6_addr[12], false);
793 	}
794 	*p = '\0';
795 
796 	return p;
797 }
798 
799 static char *ip6_string(char *p, const char *addr, const char *fmt)
800 {
801 	int i;
802 
803 	for (i = 0; i < 8; i++) {
804 		p = pack_hex_byte(p, *addr++);
805 		p = pack_hex_byte(p, *addr++);
806 		if (fmt[0] == 'I' && i != 7)
807 			*p++ = ':';
808 	}
809 	*p = '\0';
810 
811 	return p;
812 }
813 
814 static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
815 			     struct printf_spec spec, const char *fmt)
816 {
817 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
818 
819 	if (fmt[0] == 'I' && fmt[2] == 'c')
820 		ip6_compressed_string(ip6_addr, addr);
821 	else
822 		ip6_string(ip6_addr, addr, fmt);
823 
824 	return string(buf, end, ip6_addr, spec);
825 }
826 
827 static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
828 			     struct printf_spec spec, const char *fmt)
829 {
830 	char ip4_addr[sizeof("255.255.255.255")];
831 
832 	ip4_string(ip4_addr, addr, fmt[0] == 'i');
833 
834 	return string(buf, end, ip4_addr, spec);
835 }
836 
837 static char *uuid_string(char *buf, char *end, const u8 *addr,
838 			 struct printf_spec spec, const char *fmt)
839 {
840 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
841 	char *p = uuid;
842 	int i;
843 	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
844 	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
845 	const u8 *index = be;
846 	bool uc = false;
847 
848 	switch (*(++fmt)) {
849 	case 'L':
850 		uc = true;		/* fall-through */
851 	case 'l':
852 		index = le;
853 		break;
854 	case 'B':
855 		uc = true;
856 		break;
857 	}
858 
859 	for (i = 0; i < 16; i++) {
860 		p = pack_hex_byte(p, addr[index[i]]);
861 		switch (i) {
862 		case 3:
863 		case 5:
864 		case 7:
865 		case 9:
866 			*p++ = '-';
867 			break;
868 		}
869 	}
870 
871 	*p = 0;
872 
873 	if (uc) {
874 		p = uuid;
875 		do {
876 			*p = toupper(*p);
877 		} while (*(++p));
878 	}
879 
880 	return string(buf, end, uuid, spec);
881 }
882 
883 /*
884  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
885  * by an extra set of alphanumeric characters that are extended format
886  * specifiers.
887  *
888  * Right now we handle:
889  *
890  * - 'F' For symbolic function descriptor pointers with offset
891  * - 'f' For simple symbolic function names without offset
892  * - 'S' For symbolic direct pointers with offset
893  * - 's' For symbolic direct pointers without offset
894  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
895  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
896  * - 'M' For a 6-byte MAC address, it prints the address in the
897  *       usual colon-separated hex notation
898  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
899  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
900  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
901  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
902  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
903  *       IPv6 omits the colons (01020304...0f)
904  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
905  * - 'I6c' for IPv6 addresses printed as specified by
906  *       http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
907  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
908  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
909  *       Options for %pU are:
910  *         b big endian lower case hex (default)
911  *         B big endian UPPER case hex
912  *         l little endian lower case hex
913  *         L little endian UPPER case hex
914  *           big endian output byte order is:
915  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
916  *           little endian output byte order is:
917  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
918  *
919  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
920  * function pointers are really function descriptors, which contain a
921  * pointer to the real address.
922  */
923 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
924 			struct printf_spec spec)
925 {
926 	if (!ptr)
927 		return string(buf, end, "(null)", spec);
928 
929 	switch (*fmt) {
930 	case 'F':
931 	case 'f':
932 		ptr = dereference_function_descriptor(ptr);
933 		/* Fallthrough */
934 	case 'S':
935 	case 's':
936 		return symbol_string(buf, end, ptr, spec, *fmt);
937 	case 'R':
938 	case 'r':
939 		return resource_string(buf, end, ptr, spec, fmt);
940 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
941 	case 'm':			/* Contiguous: 000102030405 */
942 		return mac_address_string(buf, end, ptr, spec, fmt);
943 	case 'I':			/* Formatted IP supported
944 					 * 4:	1.2.3.4
945 					 * 6:	0001:0203:...:0708
946 					 * 6c:	1::708 or 1::1.2.3.4
947 					 */
948 	case 'i':			/* Contiguous:
949 					 * 4:	001.002.003.004
950 					 * 6:   000102...0f
951 					 */
952 		switch (fmt[1]) {
953 		case '6':
954 			return ip6_addr_string(buf, end, ptr, spec, fmt);
955 		case '4':
956 			return ip4_addr_string(buf, end, ptr, spec, fmt);
957 		}
958 		break;
959 	case 'U':
960 		return uuid_string(buf, end, ptr, spec, fmt);
961 	}
962 	spec.flags |= SMALL;
963 	if (spec.field_width == -1) {
964 		spec.field_width = 2*sizeof(void *);
965 		spec.flags |= ZEROPAD;
966 	}
967 	spec.base = 16;
968 
969 	return number(buf, end, (unsigned long) ptr, spec);
970 }
971 
972 /*
973  * Helper function to decode printf style format.
974  * Each call decode a token from the format and return the
975  * number of characters read (or likely the delta where it wants
976  * to go on the next call).
977  * The decoded token is returned through the parameters
978  *
979  * 'h', 'l', or 'L' for integer fields
980  * 'z' support added 23/7/1999 S.H.
981  * 'z' changed to 'Z' --davidm 1/25/99
982  * 't' added for ptrdiff_t
983  *
984  * @fmt: the format string
985  * @type of the token returned
986  * @flags: various flags such as +, -, # tokens..
987  * @field_width: overwritten width
988  * @base: base of the number (octal, hex, ...)
989  * @precision: precision of a number
990  * @qualifier: qualifier of a number (long, size_t, ...)
991  */
992 static int format_decode(const char *fmt, struct printf_spec *spec)
993 {
994 	const char *start = fmt;
995 
996 	/* we finished early by reading the field width */
997 	if (spec->type == FORMAT_TYPE_WIDTH) {
998 		if (spec->field_width < 0) {
999 			spec->field_width = -spec->field_width;
1000 			spec->flags |= LEFT;
1001 		}
1002 		spec->type = FORMAT_TYPE_NONE;
1003 		goto precision;
1004 	}
1005 
1006 	/* we finished early by reading the precision */
1007 	if (spec->type == FORMAT_TYPE_PRECISION) {
1008 		if (spec->precision < 0)
1009 			spec->precision = 0;
1010 
1011 		spec->type = FORMAT_TYPE_NONE;
1012 		goto qualifier;
1013 	}
1014 
1015 	/* By default */
1016 	spec->type = FORMAT_TYPE_NONE;
1017 
1018 	for (; *fmt ; ++fmt) {
1019 		if (*fmt == '%')
1020 			break;
1021 	}
1022 
1023 	/* Return the current non-format string */
1024 	if (fmt != start || !*fmt)
1025 		return fmt - start;
1026 
1027 	/* Process flags */
1028 	spec->flags = 0;
1029 
1030 	while (1) { /* this also skips first '%' */
1031 		bool found = true;
1032 
1033 		++fmt;
1034 
1035 		switch (*fmt) {
1036 		case '-': spec->flags |= LEFT;    break;
1037 		case '+': spec->flags |= PLUS;    break;
1038 		case ' ': spec->flags |= SPACE;   break;
1039 		case '#': spec->flags |= SPECIAL; break;
1040 		case '0': spec->flags |= ZEROPAD; break;
1041 		default:  found = false;
1042 		}
1043 
1044 		if (!found)
1045 			break;
1046 	}
1047 
1048 	/* get field width */
1049 	spec->field_width = -1;
1050 
1051 	if (isdigit(*fmt))
1052 		spec->field_width = skip_atoi(&fmt);
1053 	else if (*fmt == '*') {
1054 		/* it's the next argument */
1055 		spec->type = FORMAT_TYPE_WIDTH;
1056 		return ++fmt - start;
1057 	}
1058 
1059 precision:
1060 	/* get the precision */
1061 	spec->precision = -1;
1062 	if (*fmt == '.') {
1063 		++fmt;
1064 		if (isdigit(*fmt)) {
1065 			spec->precision = skip_atoi(&fmt);
1066 			if (spec->precision < 0)
1067 				spec->precision = 0;
1068 		} else if (*fmt == '*') {
1069 			/* it's the next argument */
1070 			spec->type = FORMAT_TYPE_PRECISION;
1071 			return ++fmt - start;
1072 		}
1073 	}
1074 
1075 qualifier:
1076 	/* get the conversion qualifier */
1077 	spec->qualifier = -1;
1078 	if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1079 	    TOLOWER(*fmt) == 'z' || *fmt == 't') {
1080 		spec->qualifier = *fmt++;
1081 		if (unlikely(spec->qualifier == *fmt)) {
1082 			if (spec->qualifier == 'l') {
1083 				spec->qualifier = 'L';
1084 				++fmt;
1085 			} else if (spec->qualifier == 'h') {
1086 				spec->qualifier = 'H';
1087 				++fmt;
1088 			}
1089 		}
1090 	}
1091 
1092 	/* default base */
1093 	spec->base = 10;
1094 	switch (*fmt) {
1095 	case 'c':
1096 		spec->type = FORMAT_TYPE_CHAR;
1097 		return ++fmt - start;
1098 
1099 	case 's':
1100 		spec->type = FORMAT_TYPE_STR;
1101 		return ++fmt - start;
1102 
1103 	case 'p':
1104 		spec->type = FORMAT_TYPE_PTR;
1105 		return fmt - start;
1106 		/* skip alnum */
1107 
1108 	case 'n':
1109 		spec->type = FORMAT_TYPE_NRCHARS;
1110 		return ++fmt - start;
1111 
1112 	case '%':
1113 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1114 		return ++fmt - start;
1115 
1116 	/* integer number formats - set up the flags and "break" */
1117 	case 'o':
1118 		spec->base = 8;
1119 		break;
1120 
1121 	case 'x':
1122 		spec->flags |= SMALL;
1123 
1124 	case 'X':
1125 		spec->base = 16;
1126 		break;
1127 
1128 	case 'd':
1129 	case 'i':
1130 		spec->flags |= SIGN;
1131 	case 'u':
1132 		break;
1133 
1134 	default:
1135 		spec->type = FORMAT_TYPE_INVALID;
1136 		return fmt - start;
1137 	}
1138 
1139 	if (spec->qualifier == 'L')
1140 		spec->type = FORMAT_TYPE_LONG_LONG;
1141 	else if (spec->qualifier == 'l') {
1142 		if (spec->flags & SIGN)
1143 			spec->type = FORMAT_TYPE_LONG;
1144 		else
1145 			spec->type = FORMAT_TYPE_ULONG;
1146 	} else if (TOLOWER(spec->qualifier) == 'z') {
1147 		spec->type = FORMAT_TYPE_SIZE_T;
1148 	} else if (spec->qualifier == 't') {
1149 		spec->type = FORMAT_TYPE_PTRDIFF;
1150 	} else if (spec->qualifier == 'H') {
1151 		if (spec->flags & SIGN)
1152 			spec->type = FORMAT_TYPE_BYTE;
1153 		else
1154 			spec->type = FORMAT_TYPE_UBYTE;
1155 	} else if (spec->qualifier == 'h') {
1156 		if (spec->flags & SIGN)
1157 			spec->type = FORMAT_TYPE_SHORT;
1158 		else
1159 			spec->type = FORMAT_TYPE_USHORT;
1160 	} else {
1161 		if (spec->flags & SIGN)
1162 			spec->type = FORMAT_TYPE_INT;
1163 		else
1164 			spec->type = FORMAT_TYPE_UINT;
1165 	}
1166 
1167 	return ++fmt - start;
1168 }
1169 
1170 /**
1171  * vsnprintf - Format a string and place it in a buffer
1172  * @buf: The buffer to place the result into
1173  * @size: The size of the buffer, including the trailing null space
1174  * @fmt: The format string to use
1175  * @args: Arguments for the format string
1176  *
1177  * This function follows C99 vsnprintf, but has some extensions:
1178  * %pS output the name of a text symbol with offset
1179  * %ps output the name of a text symbol without offset
1180  * %pF output the name of a function pointer with its offset
1181  * %pf output the name of a function pointer without its offset
1182  * %pR output the address range in a struct resource with decoded flags
1183  * %pr output the address range in a struct resource with raw flags
1184  * %pM output a 6-byte MAC address with colons
1185  * %pm output a 6-byte MAC address without colons
1186  * %pI4 print an IPv4 address without leading zeros
1187  * %pi4 print an IPv4 address with leading zeros
1188  * %pI6 print an IPv6 address with colons
1189  * %pi6 print an IPv6 address without colons
1190  * %pI6c print an IPv6 address as specified by
1191  *   http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
1192  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1193  *   case.
1194  * %n is ignored
1195  *
1196  * The return value is the number of characters which would
1197  * be generated for the given input, excluding the trailing
1198  * '\0', as per ISO C99. If you want to have the exact
1199  * number of characters written into @buf as return value
1200  * (not including the trailing '\0'), use vscnprintf(). If the
1201  * return is greater than or equal to @size, the resulting
1202  * string is truncated.
1203  *
1204  * Call this function if you are already dealing with a va_list.
1205  * You probably want snprintf() instead.
1206  */
1207 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1208 {
1209 	unsigned long long num;
1210 	char *str, *end;
1211 	struct printf_spec spec = {0};
1212 
1213 	/* Reject out-of-range values early.  Large positive sizes are
1214 	   used for unknown buffer sizes. */
1215 	if (WARN_ON_ONCE((int) size < 0))
1216 		return 0;
1217 
1218 	str = buf;
1219 	end = buf + size;
1220 
1221 	/* Make sure end is always >= buf */
1222 	if (end < buf) {
1223 		end = ((void *)-1);
1224 		size = end - buf;
1225 	}
1226 
1227 	while (*fmt) {
1228 		const char *old_fmt = fmt;
1229 		int read = format_decode(fmt, &spec);
1230 
1231 		fmt += read;
1232 
1233 		switch (spec.type) {
1234 		case FORMAT_TYPE_NONE: {
1235 			int copy = read;
1236 			if (str < end) {
1237 				if (copy > end - str)
1238 					copy = end - str;
1239 				memcpy(str, old_fmt, copy);
1240 			}
1241 			str += read;
1242 			break;
1243 		}
1244 
1245 		case FORMAT_TYPE_WIDTH:
1246 			spec.field_width = va_arg(args, int);
1247 			break;
1248 
1249 		case FORMAT_TYPE_PRECISION:
1250 			spec.precision = va_arg(args, int);
1251 			break;
1252 
1253 		case FORMAT_TYPE_CHAR: {
1254 			char c;
1255 
1256 			if (!(spec.flags & LEFT)) {
1257 				while (--spec.field_width > 0) {
1258 					if (str < end)
1259 						*str = ' ';
1260 					++str;
1261 
1262 				}
1263 			}
1264 			c = (unsigned char) va_arg(args, int);
1265 			if (str < end)
1266 				*str = c;
1267 			++str;
1268 			while (--spec.field_width > 0) {
1269 				if (str < end)
1270 					*str = ' ';
1271 				++str;
1272 			}
1273 			break;
1274 		}
1275 
1276 		case FORMAT_TYPE_STR:
1277 			str = string(str, end, va_arg(args, char *), spec);
1278 			break;
1279 
1280 		case FORMAT_TYPE_PTR:
1281 			str = pointer(fmt+1, str, end, va_arg(args, void *),
1282 				      spec);
1283 			while (isalnum(*fmt))
1284 				fmt++;
1285 			break;
1286 
1287 		case FORMAT_TYPE_PERCENT_CHAR:
1288 			if (str < end)
1289 				*str = '%';
1290 			++str;
1291 			break;
1292 
1293 		case FORMAT_TYPE_INVALID:
1294 			if (str < end)
1295 				*str = '%';
1296 			++str;
1297 			break;
1298 
1299 		case FORMAT_TYPE_NRCHARS: {
1300 			int qualifier = spec.qualifier;
1301 
1302 			if (qualifier == 'l') {
1303 				long *ip = va_arg(args, long *);
1304 				*ip = (str - buf);
1305 			} else if (TOLOWER(qualifier) == 'z') {
1306 				size_t *ip = va_arg(args, size_t *);
1307 				*ip = (str - buf);
1308 			} else {
1309 				int *ip = va_arg(args, int *);
1310 				*ip = (str - buf);
1311 			}
1312 			break;
1313 		}
1314 
1315 		default:
1316 			switch (spec.type) {
1317 			case FORMAT_TYPE_LONG_LONG:
1318 				num = va_arg(args, long long);
1319 				break;
1320 			case FORMAT_TYPE_ULONG:
1321 				num = va_arg(args, unsigned long);
1322 				break;
1323 			case FORMAT_TYPE_LONG:
1324 				num = va_arg(args, long);
1325 				break;
1326 			case FORMAT_TYPE_SIZE_T:
1327 				num = va_arg(args, size_t);
1328 				break;
1329 			case FORMAT_TYPE_PTRDIFF:
1330 				num = va_arg(args, ptrdiff_t);
1331 				break;
1332 			case FORMAT_TYPE_UBYTE:
1333 				num = (unsigned char) va_arg(args, int);
1334 				break;
1335 			case FORMAT_TYPE_BYTE:
1336 				num = (signed char) va_arg(args, int);
1337 				break;
1338 			case FORMAT_TYPE_USHORT:
1339 				num = (unsigned short) va_arg(args, int);
1340 				break;
1341 			case FORMAT_TYPE_SHORT:
1342 				num = (short) va_arg(args, int);
1343 				break;
1344 			case FORMAT_TYPE_INT:
1345 				num = (int) va_arg(args, int);
1346 				break;
1347 			default:
1348 				num = va_arg(args, unsigned int);
1349 			}
1350 
1351 			str = number(str, end, num, spec);
1352 		}
1353 	}
1354 
1355 	if (size > 0) {
1356 		if (str < end)
1357 			*str = '\0';
1358 		else
1359 			end[-1] = '\0';
1360 	}
1361 
1362 	/* the trailing null byte doesn't count towards the total */
1363 	return str-buf;
1364 
1365 }
1366 EXPORT_SYMBOL(vsnprintf);
1367 
1368 /**
1369  * vscnprintf - Format a string and place it in a buffer
1370  * @buf: The buffer to place the result into
1371  * @size: The size of the buffer, including the trailing null space
1372  * @fmt: The format string to use
1373  * @args: Arguments for the format string
1374  *
1375  * The return value is the number of characters which have been written into
1376  * the @buf not including the trailing '\0'. If @size is <= 0 the function
1377  * returns 0.
1378  *
1379  * Call this function if you are already dealing with a va_list.
1380  * You probably want scnprintf() instead.
1381  *
1382  * See the vsnprintf() documentation for format string extensions over C99.
1383  */
1384 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1385 {
1386 	int i;
1387 
1388 	i = vsnprintf(buf, size, fmt, args);
1389 
1390 	return (i >= size) ? (size - 1) : i;
1391 }
1392 EXPORT_SYMBOL(vscnprintf);
1393 
1394 /**
1395  * snprintf - Format a string and place it in a buffer
1396  * @buf: The buffer to place the result into
1397  * @size: The size of the buffer, including the trailing null space
1398  * @fmt: The format string to use
1399  * @...: Arguments for the format string
1400  *
1401  * The return value is the number of characters which would be
1402  * generated for the given input, excluding the trailing null,
1403  * as per ISO C99.  If the return is greater than or equal to
1404  * @size, the resulting string is truncated.
1405  *
1406  * See the vsnprintf() documentation for format string extensions over C99.
1407  */
1408 int snprintf(char *buf, size_t size, const char *fmt, ...)
1409 {
1410 	va_list args;
1411 	int i;
1412 
1413 	va_start(args, fmt);
1414 	i = vsnprintf(buf, size, fmt, args);
1415 	va_end(args);
1416 
1417 	return i;
1418 }
1419 EXPORT_SYMBOL(snprintf);
1420 
1421 /**
1422  * scnprintf - Format a string and place it in a buffer
1423  * @buf: The buffer to place the result into
1424  * @size: The size of the buffer, including the trailing null space
1425  * @fmt: The format string to use
1426  * @...: Arguments for the format string
1427  *
1428  * The return value is the number of characters written into @buf not including
1429  * the trailing '\0'. If @size is <= 0 the function returns 0.
1430  */
1431 
1432 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1433 {
1434 	va_list args;
1435 	int i;
1436 
1437 	va_start(args, fmt);
1438 	i = vsnprintf(buf, size, fmt, args);
1439 	va_end(args);
1440 
1441 	return (i >= size) ? (size - 1) : i;
1442 }
1443 EXPORT_SYMBOL(scnprintf);
1444 
1445 /**
1446  * vsprintf - Format a string and place it in a buffer
1447  * @buf: The buffer to place the result into
1448  * @fmt: The format string to use
1449  * @args: Arguments for the format string
1450  *
1451  * The function returns the number of characters written
1452  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1453  * buffer overflows.
1454  *
1455  * Call this function if you are already dealing with a va_list.
1456  * You probably want sprintf() instead.
1457  *
1458  * See the vsnprintf() documentation for format string extensions over C99.
1459  */
1460 int vsprintf(char *buf, const char *fmt, va_list args)
1461 {
1462 	return vsnprintf(buf, INT_MAX, fmt, args);
1463 }
1464 EXPORT_SYMBOL(vsprintf);
1465 
1466 /**
1467  * sprintf - Format a string and place it in a buffer
1468  * @buf: The buffer to place the result into
1469  * @fmt: The format string to use
1470  * @...: Arguments for the format string
1471  *
1472  * The function returns the number of characters written
1473  * into @buf. Use snprintf() or scnprintf() in order to avoid
1474  * buffer overflows.
1475  *
1476  * See the vsnprintf() documentation for format string extensions over C99.
1477  */
1478 int sprintf(char *buf, const char *fmt, ...)
1479 {
1480 	va_list args;
1481 	int i;
1482 
1483 	va_start(args, fmt);
1484 	i = vsnprintf(buf, INT_MAX, fmt, args);
1485 	va_end(args);
1486 
1487 	return i;
1488 }
1489 EXPORT_SYMBOL(sprintf);
1490 
1491 #ifdef CONFIG_BINARY_PRINTF
1492 /*
1493  * bprintf service:
1494  * vbin_printf() - VA arguments to binary data
1495  * bstr_printf() - Binary data to text string
1496  */
1497 
1498 /**
1499  * vbin_printf - Parse a format string and place args' binary value in a buffer
1500  * @bin_buf: The buffer to place args' binary value
1501  * @size: The size of the buffer(by words(32bits), not characters)
1502  * @fmt: The format string to use
1503  * @args: Arguments for the format string
1504  *
1505  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1506  * is skiped.
1507  *
1508  * The return value is the number of words(32bits) which would be generated for
1509  * the given input.
1510  *
1511  * NOTE:
1512  * If the return value is greater than @size, the resulting bin_buf is NOT
1513  * valid for bstr_printf().
1514  */
1515 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1516 {
1517 	struct printf_spec spec = {0};
1518 	char *str, *end;
1519 
1520 	str = (char *)bin_buf;
1521 	end = (char *)(bin_buf + size);
1522 
1523 #define save_arg(type)							\
1524 do {									\
1525 	if (sizeof(type) == 8) {					\
1526 		unsigned long long value;				\
1527 		str = PTR_ALIGN(str, sizeof(u32));			\
1528 		value = va_arg(args, unsigned long long);		\
1529 		if (str + sizeof(type) <= end) {			\
1530 			*(u32 *)str = *(u32 *)&value;			\
1531 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
1532 		}							\
1533 	} else {							\
1534 		unsigned long value;					\
1535 		str = PTR_ALIGN(str, sizeof(type));			\
1536 		value = va_arg(args, int);				\
1537 		if (str + sizeof(type) <= end)				\
1538 			*(typeof(type) *)str = (type)value;		\
1539 	}								\
1540 	str += sizeof(type);						\
1541 } while (0)
1542 
1543 	while (*fmt) {
1544 		int read = format_decode(fmt, &spec);
1545 
1546 		fmt += read;
1547 
1548 		switch (spec.type) {
1549 		case FORMAT_TYPE_NONE:
1550 		case FORMAT_TYPE_INVALID:
1551 		case FORMAT_TYPE_PERCENT_CHAR:
1552 			break;
1553 
1554 		case FORMAT_TYPE_WIDTH:
1555 		case FORMAT_TYPE_PRECISION:
1556 			save_arg(int);
1557 			break;
1558 
1559 		case FORMAT_TYPE_CHAR:
1560 			save_arg(char);
1561 			break;
1562 
1563 		case FORMAT_TYPE_STR: {
1564 			const char *save_str = va_arg(args, char *);
1565 			size_t len;
1566 
1567 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1568 					|| (unsigned long)save_str < PAGE_SIZE)
1569 				save_str = "(null)";
1570 			len = strlen(save_str) + 1;
1571 			if (str + len < end)
1572 				memcpy(str, save_str, len);
1573 			str += len;
1574 			break;
1575 		}
1576 
1577 		case FORMAT_TYPE_PTR:
1578 			save_arg(void *);
1579 			/* skip all alphanumeric pointer suffixes */
1580 			while (isalnum(*fmt))
1581 				fmt++;
1582 			break;
1583 
1584 		case FORMAT_TYPE_NRCHARS: {
1585 			/* skip %n 's argument */
1586 			int qualifier = spec.qualifier;
1587 			void *skip_arg;
1588 			if (qualifier == 'l')
1589 				skip_arg = va_arg(args, long *);
1590 			else if (TOLOWER(qualifier) == 'z')
1591 				skip_arg = va_arg(args, size_t *);
1592 			else
1593 				skip_arg = va_arg(args, int *);
1594 			break;
1595 		}
1596 
1597 		default:
1598 			switch (spec.type) {
1599 
1600 			case FORMAT_TYPE_LONG_LONG:
1601 				save_arg(long long);
1602 				break;
1603 			case FORMAT_TYPE_ULONG:
1604 			case FORMAT_TYPE_LONG:
1605 				save_arg(unsigned long);
1606 				break;
1607 			case FORMAT_TYPE_SIZE_T:
1608 				save_arg(size_t);
1609 				break;
1610 			case FORMAT_TYPE_PTRDIFF:
1611 				save_arg(ptrdiff_t);
1612 				break;
1613 			case FORMAT_TYPE_UBYTE:
1614 			case FORMAT_TYPE_BYTE:
1615 				save_arg(char);
1616 				break;
1617 			case FORMAT_TYPE_USHORT:
1618 			case FORMAT_TYPE_SHORT:
1619 				save_arg(short);
1620 				break;
1621 			default:
1622 				save_arg(int);
1623 			}
1624 		}
1625 	}
1626 
1627 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1628 #undef save_arg
1629 }
1630 EXPORT_SYMBOL_GPL(vbin_printf);
1631 
1632 /**
1633  * bstr_printf - Format a string from binary arguments and place it in a buffer
1634  * @buf: The buffer to place the result into
1635  * @size: The size of the buffer, including the trailing null space
1636  * @fmt: The format string to use
1637  * @bin_buf: Binary arguments for the format string
1638  *
1639  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1640  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1641  * a binary buffer that generated by vbin_printf.
1642  *
1643  * The format follows C99 vsnprintf, but has some extensions:
1644  *  see vsnprintf comment for details.
1645  *
1646  * The return value is the number of characters which would
1647  * be generated for the given input, excluding the trailing
1648  * '\0', as per ISO C99. If you want to have the exact
1649  * number of characters written into @buf as return value
1650  * (not including the trailing '\0'), use vscnprintf(). If the
1651  * return is greater than or equal to @size, the resulting
1652  * string is truncated.
1653  */
1654 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1655 {
1656 	struct printf_spec spec = {0};
1657 	char *str, *end;
1658 	const char *args = (const char *)bin_buf;
1659 
1660 	if (WARN_ON_ONCE((int) size < 0))
1661 		return 0;
1662 
1663 	str = buf;
1664 	end = buf + size;
1665 
1666 #define get_arg(type)							\
1667 ({									\
1668 	typeof(type) value;						\
1669 	if (sizeof(type) == 8) {					\
1670 		args = PTR_ALIGN(args, sizeof(u32));			\
1671 		*(u32 *)&value = *(u32 *)args;				\
1672 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
1673 	} else {							\
1674 		args = PTR_ALIGN(args, sizeof(type));			\
1675 		value = *(typeof(type) *)args;				\
1676 	}								\
1677 	args += sizeof(type);						\
1678 	value;								\
1679 })
1680 
1681 	/* Make sure end is always >= buf */
1682 	if (end < buf) {
1683 		end = ((void *)-1);
1684 		size = end - buf;
1685 	}
1686 
1687 	while (*fmt) {
1688 		const char *old_fmt = fmt;
1689 		int read = format_decode(fmt, &spec);
1690 
1691 		fmt += read;
1692 
1693 		switch (spec.type) {
1694 		case FORMAT_TYPE_NONE: {
1695 			int copy = read;
1696 			if (str < end) {
1697 				if (copy > end - str)
1698 					copy = end - str;
1699 				memcpy(str, old_fmt, copy);
1700 			}
1701 			str += read;
1702 			break;
1703 		}
1704 
1705 		case FORMAT_TYPE_WIDTH:
1706 			spec.field_width = get_arg(int);
1707 			break;
1708 
1709 		case FORMAT_TYPE_PRECISION:
1710 			spec.precision = get_arg(int);
1711 			break;
1712 
1713 		case FORMAT_TYPE_CHAR: {
1714 			char c;
1715 
1716 			if (!(spec.flags & LEFT)) {
1717 				while (--spec.field_width > 0) {
1718 					if (str < end)
1719 						*str = ' ';
1720 					++str;
1721 				}
1722 			}
1723 			c = (unsigned char) get_arg(char);
1724 			if (str < end)
1725 				*str = c;
1726 			++str;
1727 			while (--spec.field_width > 0) {
1728 				if (str < end)
1729 					*str = ' ';
1730 				++str;
1731 			}
1732 			break;
1733 		}
1734 
1735 		case FORMAT_TYPE_STR: {
1736 			const char *str_arg = args;
1737 			args += strlen(str_arg) + 1;
1738 			str = string(str, end, (char *)str_arg, spec);
1739 			break;
1740 		}
1741 
1742 		case FORMAT_TYPE_PTR:
1743 			str = pointer(fmt+1, str, end, get_arg(void *), spec);
1744 			while (isalnum(*fmt))
1745 				fmt++;
1746 			break;
1747 
1748 		case FORMAT_TYPE_PERCENT_CHAR:
1749 		case FORMAT_TYPE_INVALID:
1750 			if (str < end)
1751 				*str = '%';
1752 			++str;
1753 			break;
1754 
1755 		case FORMAT_TYPE_NRCHARS:
1756 			/* skip */
1757 			break;
1758 
1759 		default: {
1760 			unsigned long long num;
1761 
1762 			switch (spec.type) {
1763 
1764 			case FORMAT_TYPE_LONG_LONG:
1765 				num = get_arg(long long);
1766 				break;
1767 			case FORMAT_TYPE_ULONG:
1768 			case FORMAT_TYPE_LONG:
1769 				num = get_arg(unsigned long);
1770 				break;
1771 			case FORMAT_TYPE_SIZE_T:
1772 				num = get_arg(size_t);
1773 				break;
1774 			case FORMAT_TYPE_PTRDIFF:
1775 				num = get_arg(ptrdiff_t);
1776 				break;
1777 			case FORMAT_TYPE_UBYTE:
1778 				num = get_arg(unsigned char);
1779 				break;
1780 			case FORMAT_TYPE_BYTE:
1781 				num = get_arg(signed char);
1782 				break;
1783 			case FORMAT_TYPE_USHORT:
1784 				num = get_arg(unsigned short);
1785 				break;
1786 			case FORMAT_TYPE_SHORT:
1787 				num = get_arg(short);
1788 				break;
1789 			case FORMAT_TYPE_UINT:
1790 				num = get_arg(unsigned int);
1791 				break;
1792 			default:
1793 				num = get_arg(int);
1794 			}
1795 
1796 			str = number(str, end, num, spec);
1797 		} /* default: */
1798 		} /* switch(spec.type) */
1799 	} /* while(*fmt) */
1800 
1801 	if (size > 0) {
1802 		if (str < end)
1803 			*str = '\0';
1804 		else
1805 			end[-1] = '\0';
1806 	}
1807 
1808 #undef get_arg
1809 
1810 	/* the trailing null byte doesn't count towards the total */
1811 	return str - buf;
1812 }
1813 EXPORT_SYMBOL_GPL(bstr_printf);
1814 
1815 /**
1816  * bprintf - Parse a format string and place args' binary value in a buffer
1817  * @bin_buf: The buffer to place args' binary value
1818  * @size: The size of the buffer(by words(32bits), not characters)
1819  * @fmt: The format string to use
1820  * @...: Arguments for the format string
1821  *
1822  * The function returns the number of words(u32) written
1823  * into @bin_buf.
1824  */
1825 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1826 {
1827 	va_list args;
1828 	int ret;
1829 
1830 	va_start(args, fmt);
1831 	ret = vbin_printf(bin_buf, size, fmt, args);
1832 	va_end(args);
1833 
1834 	return ret;
1835 }
1836 EXPORT_SYMBOL_GPL(bprintf);
1837 
1838 #endif /* CONFIG_BINARY_PRINTF */
1839 
1840 /**
1841  * vsscanf - Unformat a buffer into a list of arguments
1842  * @buf:	input buffer
1843  * @fmt:	format of buffer
1844  * @args:	arguments
1845  */
1846 int vsscanf(const char *buf, const char *fmt, va_list args)
1847 {
1848 	const char *str = buf;
1849 	char *next;
1850 	char digit;
1851 	int num = 0;
1852 	int qualifier, base, field_width;
1853 	bool is_sign;
1854 
1855 	while (*fmt && *str) {
1856 		/* skip any white space in format */
1857 		/* white space in format matchs any amount of
1858 		 * white space, including none, in the input.
1859 		 */
1860 		if (isspace(*fmt)) {
1861 			fmt = skip_spaces(++fmt);
1862 			str = skip_spaces(str);
1863 		}
1864 
1865 		/* anything that is not a conversion must match exactly */
1866 		if (*fmt != '%' && *fmt) {
1867 			if (*fmt++ != *str++)
1868 				break;
1869 			continue;
1870 		}
1871 
1872 		if (!*fmt)
1873 			break;
1874 		++fmt;
1875 
1876 		/* skip this conversion.
1877 		 * advance both strings to next white space
1878 		 */
1879 		if (*fmt == '*') {
1880 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
1881 				fmt++;
1882 			while (!isspace(*str) && *str)
1883 				str++;
1884 			continue;
1885 		}
1886 
1887 		/* get field width */
1888 		field_width = -1;
1889 		if (isdigit(*fmt))
1890 			field_width = skip_atoi(&fmt);
1891 
1892 		/* get conversion qualifier */
1893 		qualifier = -1;
1894 		if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1895 		    TOLOWER(*fmt) == 'z') {
1896 			qualifier = *fmt++;
1897 			if (unlikely(qualifier == *fmt)) {
1898 				if (qualifier == 'h') {
1899 					qualifier = 'H';
1900 					fmt++;
1901 				} else if (qualifier == 'l') {
1902 					qualifier = 'L';
1903 					fmt++;
1904 				}
1905 			}
1906 		}
1907 
1908 		if (!*fmt || !*str)
1909 			break;
1910 
1911 		base = 10;
1912 		is_sign = 0;
1913 
1914 		switch (*fmt++) {
1915 		case 'c':
1916 		{
1917 			char *s = (char *)va_arg(args, char*);
1918 			if (field_width == -1)
1919 				field_width = 1;
1920 			do {
1921 				*s++ = *str++;
1922 			} while (--field_width > 0 && *str);
1923 			num++;
1924 		}
1925 		continue;
1926 		case 's':
1927 		{
1928 			char *s = (char *)va_arg(args, char *);
1929 			if (field_width == -1)
1930 				field_width = INT_MAX;
1931 			/* first, skip leading white space in buffer */
1932 			str = skip_spaces(str);
1933 
1934 			/* now copy until next white space */
1935 			while (*str && !isspace(*str) && field_width--)
1936 				*s++ = *str++;
1937 			*s = '\0';
1938 			num++;
1939 		}
1940 		continue;
1941 		case 'n':
1942 			/* return number of characters read so far */
1943 		{
1944 			int *i = (int *)va_arg(args, int*);
1945 			*i = str - buf;
1946 		}
1947 		continue;
1948 		case 'o':
1949 			base = 8;
1950 			break;
1951 		case 'x':
1952 		case 'X':
1953 			base = 16;
1954 			break;
1955 		case 'i':
1956 			base = 0;
1957 		case 'd':
1958 			is_sign = 1;
1959 		case 'u':
1960 			break;
1961 		case '%':
1962 			/* looking for '%' in str */
1963 			if (*str++ != '%')
1964 				return num;
1965 			continue;
1966 		default:
1967 			/* invalid format; stop here */
1968 			return num;
1969 		}
1970 
1971 		/* have some sort of integer conversion.
1972 		 * first, skip white space in buffer.
1973 		 */
1974 		str = skip_spaces(str);
1975 
1976 		digit = *str;
1977 		if (is_sign && digit == '-')
1978 			digit = *(str + 1);
1979 
1980 		if (!digit
1981 		    || (base == 16 && !isxdigit(digit))
1982 		    || (base == 10 && !isdigit(digit))
1983 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
1984 		    || (base == 0 && !isdigit(digit)))
1985 			break;
1986 
1987 		switch (qualifier) {
1988 		case 'H':	/* that's 'hh' in format */
1989 			if (is_sign) {
1990 				signed char *s = (signed char *)va_arg(args, signed char *);
1991 				*s = (signed char)simple_strtol(str, &next, base);
1992 			} else {
1993 				unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1994 				*s = (unsigned char)simple_strtoul(str, &next, base);
1995 			}
1996 			break;
1997 		case 'h':
1998 			if (is_sign) {
1999 				short *s = (short *)va_arg(args, short *);
2000 				*s = (short)simple_strtol(str, &next, base);
2001 			} else {
2002 				unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2003 				*s = (unsigned short)simple_strtoul(str, &next, base);
2004 			}
2005 			break;
2006 		case 'l':
2007 			if (is_sign) {
2008 				long *l = (long *)va_arg(args, long *);
2009 				*l = simple_strtol(str, &next, base);
2010 			} else {
2011 				unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2012 				*l = simple_strtoul(str, &next, base);
2013 			}
2014 			break;
2015 		case 'L':
2016 			if (is_sign) {
2017 				long long *l = (long long *)va_arg(args, long long *);
2018 				*l = simple_strtoll(str, &next, base);
2019 			} else {
2020 				unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2021 				*l = simple_strtoull(str, &next, base);
2022 			}
2023 			break;
2024 		case 'Z':
2025 		case 'z':
2026 		{
2027 			size_t *s = (size_t *)va_arg(args, size_t *);
2028 			*s = (size_t)simple_strtoul(str, &next, base);
2029 		}
2030 		break;
2031 		default:
2032 			if (is_sign) {
2033 				int *i = (int *)va_arg(args, int *);
2034 				*i = (int)simple_strtol(str, &next, base);
2035 			} else {
2036 				unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2037 				*i = (unsigned int)simple_strtoul(str, &next, base);
2038 			}
2039 			break;
2040 		}
2041 		num++;
2042 
2043 		if (!next)
2044 			break;
2045 		str = next;
2046 	}
2047 
2048 	/*
2049 	 * Now we've come all the way through so either the input string or the
2050 	 * format ended. In the former case, there can be a %n at the current
2051 	 * position in the format that needs to be filled.
2052 	 */
2053 	if (*fmt == '%' && *(fmt + 1) == 'n') {
2054 		int *p = (int *)va_arg(args, int *);
2055 		*p = str - buf;
2056 	}
2057 
2058 	return num;
2059 }
2060 EXPORT_SYMBOL(vsscanf);
2061 
2062 /**
2063  * sscanf - Unformat a buffer into a list of arguments
2064  * @buf:	input buffer
2065  * @fmt:	formatting of buffer
2066  * @...:	resulting arguments
2067  */
2068 int sscanf(const char *buf, const char *fmt, ...)
2069 {
2070 	va_list args;
2071 	int i;
2072 
2073 	va_start(args, fmt);
2074 	i = vsscanf(buf, fmt, args);
2075 	va_end(args);
2076 
2077 	return i;
2078 }
2079 EXPORT_SYMBOL(sscanf);
2080