xref: /linux/lib/vsprintf.c (revision a0b54e256d513ed99e456bea6e4e188ff92e7c46)
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')
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)
599 {
600 #ifndef IO_RSRC_PRINTK_SIZE
601 #define IO_RSRC_PRINTK_SIZE	4
602 #endif
603 
604 #ifndef MEM_RSRC_PRINTK_SIZE
605 #define MEM_RSRC_PRINTK_SIZE	8
606 #endif
607 	struct printf_spec num_spec = {
608 		.base = 16,
609 		.precision = -1,
610 		.flags = SPECIAL | SMALL | ZEROPAD,
611 	};
612 	/* room for the actual numbers, the two "0x", -, [, ] and the final zero */
613 	char sym[4*sizeof(resource_size_t) + 8];
614 	char *p = sym, *pend = sym + sizeof(sym);
615 	int size = -1;
616 
617 	if (res->flags & IORESOURCE_IO)
618 		size = IO_RSRC_PRINTK_SIZE;
619 	else if (res->flags & IORESOURCE_MEM)
620 		size = MEM_RSRC_PRINTK_SIZE;
621 
622 	*p++ = '[';
623 	num_spec.field_width = size;
624 	p = number(p, pend, res->start, num_spec);
625 	*p++ = '-';
626 	p = number(p, pend, res->end, num_spec);
627 	*p++ = ']';
628 	*p = 0;
629 
630 	return string(buf, end, sym, spec);
631 }
632 
633 static char *mac_address_string(char *buf, char *end, u8 *addr,
634 				struct printf_spec spec, const char *fmt)
635 {
636 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
637 	char *p = mac_addr;
638 	int i;
639 
640 	for (i = 0; i < 6; i++) {
641 		p = pack_hex_byte(p, addr[i]);
642 		if (fmt[0] == 'M' && i != 5)
643 			*p++ = ':';
644 	}
645 	*p = '\0';
646 
647 	return string(buf, end, mac_addr, spec);
648 }
649 
650 static char *ip4_string(char *p, const u8 *addr, bool leading_zeros)
651 {
652 	int i;
653 
654 	for (i = 0; i < 4; i++) {
655 		char temp[3];	/* hold each IP quad in reverse order */
656 		int digits = put_dec_trunc(temp, addr[i]) - temp;
657 		if (leading_zeros) {
658 			if (digits < 3)
659 				*p++ = '0';
660 			if (digits < 2)
661 				*p++ = '0';
662 		}
663 		/* reverse the digits in the quad */
664 		while (digits--)
665 			*p++ = temp[digits];
666 		if (i < 3)
667 			*p++ = '.';
668 	}
669 
670 	*p = '\0';
671 	return p;
672 }
673 
674 static char *ip6_compressed_string(char *p, const struct in6_addr *addr)
675 {
676 	int i;
677 	int j;
678 	int range;
679 	unsigned char zerolength[8];
680 	int longest = 1;
681 	int colonpos = -1;
682 	u16 word;
683 	u8 hi;
684 	u8 lo;
685 	bool needcolon = false;
686 	bool useIPv4 = ipv6_addr_v4mapped(addr) || ipv6_addr_is_isatap(addr);
687 
688 	memset(zerolength, 0, sizeof(zerolength));
689 
690 	if (useIPv4)
691 		range = 6;
692 	else
693 		range = 8;
694 
695 	/* find position of longest 0 run */
696 	for (i = 0; i < range; i++) {
697 		for (j = i; j < range; j++) {
698 			if (addr->s6_addr16[j] != 0)
699 				break;
700 			zerolength[i]++;
701 		}
702 	}
703 	for (i = 0; i < range; i++) {
704 		if (zerolength[i] > longest) {
705 			longest = zerolength[i];
706 			colonpos = i;
707 		}
708 	}
709 
710 	/* emit address */
711 	for (i = 0; i < range; i++) {
712 		if (i == colonpos) {
713 			if (needcolon || i == 0)
714 				*p++ = ':';
715 			*p++ = ':';
716 			needcolon = false;
717 			i += longest - 1;
718 			continue;
719 		}
720 		if (needcolon) {
721 			*p++ = ':';
722 			needcolon = false;
723 		}
724 		/* hex u16 without leading 0s */
725 		word = ntohs(addr->s6_addr16[i]);
726 		hi = word >> 8;
727 		lo = word & 0xff;
728 		if (hi) {
729 			if (hi > 0x0f)
730 				p = pack_hex_byte(p, hi);
731 			else
732 				*p++ = hex_asc_lo(hi);
733 		}
734 		if (hi || lo > 0x0f)
735 			p = pack_hex_byte(p, lo);
736 		else
737 			*p++ = hex_asc_lo(lo);
738 		needcolon = true;
739 	}
740 
741 	if (useIPv4) {
742 		if (needcolon)
743 			*p++ = ':';
744 		p = ip4_string(p, &addr->s6_addr[12], false);
745 	}
746 
747 	*p = '\0';
748 	return p;
749 }
750 
751 static char *ip6_string(char *p, const struct in6_addr *addr, const char *fmt)
752 {
753 	int i;
754 	for (i = 0; i < 8; i++) {
755 		p = pack_hex_byte(p, addr->s6_addr[2 * i]);
756 		p = pack_hex_byte(p, addr->s6_addr[2 * i + 1]);
757 		if (fmt[0] == 'I' && i != 7)
758 			*p++ = ':';
759 	}
760 
761 	*p = '\0';
762 	return p;
763 }
764 
765 static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
766 			     struct printf_spec spec, const char *fmt)
767 {
768 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
769 
770 	if (fmt[0] == 'I' && fmt[2] == 'c')
771 		ip6_compressed_string(ip6_addr, (const struct in6_addr *)addr);
772 	else
773 		ip6_string(ip6_addr, (const struct in6_addr *)addr, fmt);
774 
775 	return string(buf, end, ip6_addr, spec);
776 }
777 
778 static char *ip4_addr_string(char *buf, char *end, const u8 *addr,
779 			     struct printf_spec spec, const char *fmt)
780 {
781 	char ip4_addr[sizeof("255.255.255.255")];
782 
783 	ip4_string(ip4_addr, addr, fmt[0] == 'i');
784 
785 	return string(buf, end, ip4_addr, spec);
786 }
787 
788 /*
789  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
790  * by an extra set of alphanumeric characters that are extended format
791  * specifiers.
792  *
793  * Right now we handle:
794  *
795  * - 'F' For symbolic function descriptor pointers with offset
796  * - 'f' For simple symbolic function names without offset
797  * - 'S' For symbolic direct pointers
798  * - 'R' For a struct resource pointer, it prints the range of
799  *       addresses (not the name nor the flags)
800  * - 'M' For a 6-byte MAC address, it prints the address in the
801  *       usual colon-separated hex notation
802  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
803  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
804  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
805  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
806  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
807  *       IPv6 omits the colons (01020304...0f)
808  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
809  * - 'I6c' for IPv6 addresses printed as specified by
810  *       http://www.ietf.org/id/draft-kawamura-ipv6-text-representation-03.txt
811  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
812  * function pointers are really function descriptors, which contain a
813  * pointer to the real address.
814  */
815 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
816 			struct printf_spec spec)
817 {
818 	if (!ptr)
819 		return string(buf, end, "(null)", spec);
820 
821 	switch (*fmt) {
822 	case 'F':
823 	case 'f':
824 		ptr = dereference_function_descriptor(ptr);
825 		/* Fallthrough */
826 	case 'S':
827 		return symbol_string(buf, end, ptr, spec, *fmt);
828 	case 'R':
829 		return resource_string(buf, end, ptr, spec);
830 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
831 	case 'm':			/* Contiguous: 000102030405 */
832 		return mac_address_string(buf, end, ptr, spec, fmt);
833 	case 'I':			/* Formatted IP supported
834 					 * 4:	1.2.3.4
835 					 * 6:	0001:0203:...:0708
836 					 * 6c:	1::708 or 1::1.2.3.4
837 					 */
838 	case 'i':			/* Contiguous:
839 					 * 4:	001.002.003.004
840 					 * 6:   000102...0f
841 					 */
842 		switch (fmt[1]) {
843 		case '6':
844 			return ip6_addr_string(buf, end, ptr, spec, fmt);
845 		case '4':
846 			return ip4_addr_string(buf, end, ptr, spec, fmt);
847 		}
848 		break;
849 	}
850 	spec.flags |= SMALL;
851 	if (spec.field_width == -1) {
852 		spec.field_width = 2*sizeof(void *);
853 		spec.flags |= ZEROPAD;
854 	}
855 	spec.base = 16;
856 
857 	return number(buf, end, (unsigned long) ptr, spec);
858 }
859 
860 /*
861  * Helper function to decode printf style format.
862  * Each call decode a token from the format and return the
863  * number of characters read (or likely the delta where it wants
864  * to go on the next call).
865  * The decoded token is returned through the parameters
866  *
867  * 'h', 'l', or 'L' for integer fields
868  * 'z' support added 23/7/1999 S.H.
869  * 'z' changed to 'Z' --davidm 1/25/99
870  * 't' added for ptrdiff_t
871  *
872  * @fmt: the format string
873  * @type of the token returned
874  * @flags: various flags such as +, -, # tokens..
875  * @field_width: overwritten width
876  * @base: base of the number (octal, hex, ...)
877  * @precision: precision of a number
878  * @qualifier: qualifier of a number (long, size_t, ...)
879  */
880 static int format_decode(const char *fmt, struct printf_spec *spec)
881 {
882 	const char *start = fmt;
883 
884 	/* we finished early by reading the field width */
885 	if (spec->type == FORMAT_TYPE_WIDTH) {
886 		if (spec->field_width < 0) {
887 			spec->field_width = -spec->field_width;
888 			spec->flags |= LEFT;
889 		}
890 		spec->type = FORMAT_TYPE_NONE;
891 		goto precision;
892 	}
893 
894 	/* we finished early by reading the precision */
895 	if (spec->type == FORMAT_TYPE_PRECISION) {
896 		if (spec->precision < 0)
897 			spec->precision = 0;
898 
899 		spec->type = FORMAT_TYPE_NONE;
900 		goto qualifier;
901 	}
902 
903 	/* By default */
904 	spec->type = FORMAT_TYPE_NONE;
905 
906 	for (; *fmt ; ++fmt) {
907 		if (*fmt == '%')
908 			break;
909 	}
910 
911 	/* Return the current non-format string */
912 	if (fmt != start || !*fmt)
913 		return fmt - start;
914 
915 	/* Process flags */
916 	spec->flags = 0;
917 
918 	while (1) { /* this also skips first '%' */
919 		bool found = true;
920 
921 		++fmt;
922 
923 		switch (*fmt) {
924 		case '-': spec->flags |= LEFT;    break;
925 		case '+': spec->flags |= PLUS;    break;
926 		case ' ': spec->flags |= SPACE;   break;
927 		case '#': spec->flags |= SPECIAL; break;
928 		case '0': spec->flags |= ZEROPAD; break;
929 		default:  found = false;
930 		}
931 
932 		if (!found)
933 			break;
934 	}
935 
936 	/* get field width */
937 	spec->field_width = -1;
938 
939 	if (isdigit(*fmt))
940 		spec->field_width = skip_atoi(&fmt);
941 	else if (*fmt == '*') {
942 		/* it's the next argument */
943 		spec->type = FORMAT_TYPE_WIDTH;
944 		return ++fmt - start;
945 	}
946 
947 precision:
948 	/* get the precision */
949 	spec->precision = -1;
950 	if (*fmt == '.') {
951 		++fmt;
952 		if (isdigit(*fmt)) {
953 			spec->precision = skip_atoi(&fmt);
954 			if (spec->precision < 0)
955 				spec->precision = 0;
956 		} else if (*fmt == '*') {
957 			/* it's the next argument */
958 			spec->type = FORMAT_TYPE_PRECISION;
959 			return ++fmt - start;
960 		}
961 	}
962 
963 qualifier:
964 	/* get the conversion qualifier */
965 	spec->qualifier = -1;
966 	if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
967 	    *fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
968 		spec->qualifier = *fmt++;
969 		if (unlikely(spec->qualifier == *fmt)) {
970 			if (spec->qualifier == 'l') {
971 				spec->qualifier = 'L';
972 				++fmt;
973 			} else if (spec->qualifier == 'h') {
974 				spec->qualifier = 'H';
975 				++fmt;
976 			}
977 		}
978 	}
979 
980 	/* default base */
981 	spec->base = 10;
982 	switch (*fmt) {
983 	case 'c':
984 		spec->type = FORMAT_TYPE_CHAR;
985 		return ++fmt - start;
986 
987 	case 's':
988 		spec->type = FORMAT_TYPE_STR;
989 		return ++fmt - start;
990 
991 	case 'p':
992 		spec->type = FORMAT_TYPE_PTR;
993 		return fmt - start;
994 		/* skip alnum */
995 
996 	case 'n':
997 		spec->type = FORMAT_TYPE_NRCHARS;
998 		return ++fmt - start;
999 
1000 	case '%':
1001 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1002 		return ++fmt - start;
1003 
1004 	/* integer number formats - set up the flags and "break" */
1005 	case 'o':
1006 		spec->base = 8;
1007 		break;
1008 
1009 	case 'x':
1010 		spec->flags |= SMALL;
1011 
1012 	case 'X':
1013 		spec->base = 16;
1014 		break;
1015 
1016 	case 'd':
1017 	case 'i':
1018 		spec->flags |= SIGN;
1019 	case 'u':
1020 		break;
1021 
1022 	default:
1023 		spec->type = FORMAT_TYPE_INVALID;
1024 		return fmt - start;
1025 	}
1026 
1027 	if (spec->qualifier == 'L')
1028 		spec->type = FORMAT_TYPE_LONG_LONG;
1029 	else if (spec->qualifier == 'l') {
1030 		if (spec->flags & SIGN)
1031 			spec->type = FORMAT_TYPE_LONG;
1032 		else
1033 			spec->type = FORMAT_TYPE_ULONG;
1034 	} else if (spec->qualifier == 'Z' || spec->qualifier == 'z') {
1035 		spec->type = FORMAT_TYPE_SIZE_T;
1036 	} else if (spec->qualifier == 't') {
1037 		spec->type = FORMAT_TYPE_PTRDIFF;
1038 	} else if (spec->qualifier == 'H') {
1039 		if (spec->flags & SIGN)
1040 			spec->type = FORMAT_TYPE_BYTE;
1041 		else
1042 			spec->type = FORMAT_TYPE_UBYTE;
1043 	} else if (spec->qualifier == 'h') {
1044 		if (spec->flags & SIGN)
1045 			spec->type = FORMAT_TYPE_SHORT;
1046 		else
1047 			spec->type = FORMAT_TYPE_USHORT;
1048 	} else {
1049 		if (spec->flags & SIGN)
1050 			spec->type = FORMAT_TYPE_INT;
1051 		else
1052 			spec->type = FORMAT_TYPE_UINT;
1053 	}
1054 
1055 	return ++fmt - start;
1056 }
1057 
1058 /**
1059  * vsnprintf - Format a string and place it in a buffer
1060  * @buf: The buffer to place the result into
1061  * @size: The size of the buffer, including the trailing null space
1062  * @fmt: The format string to use
1063  * @args: Arguments for the format string
1064  *
1065  * This function follows C99 vsnprintf, but has some extensions:
1066  * %pS output the name of a text symbol
1067  * %pF output the name of a function pointer with its offset
1068  * %pf output the name of a function pointer without its offset
1069  * %pR output the address range in a struct resource
1070  *
1071  * The return value is the number of characters which would
1072  * be generated for the given input, excluding the trailing
1073  * '\0', as per ISO C99. If you want to have the exact
1074  * number of characters written into @buf as return value
1075  * (not including the trailing '\0'), use vscnprintf(). If the
1076  * return is greater than or equal to @size, the resulting
1077  * string is truncated.
1078  *
1079  * Call this function if you are already dealing with a va_list.
1080  * You probably want snprintf() instead.
1081  */
1082 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1083 {
1084 	unsigned long long num;
1085 	char *str, *end, c;
1086 	int read;
1087 	struct printf_spec spec = {0};
1088 
1089 	/* Reject out-of-range values early.  Large positive sizes are
1090 	   used for unknown buffer sizes. */
1091 	if (unlikely((int) size < 0)) {
1092 		/* There can be only one.. */
1093 		static char warn = 1;
1094 		WARN_ON(warn);
1095 		warn = 0;
1096 		return 0;
1097 	}
1098 
1099 	str = buf;
1100 	end = buf + size;
1101 
1102 	/* Make sure end is always >= buf */
1103 	if (end < buf) {
1104 		end = ((void *)-1);
1105 		size = end - buf;
1106 	}
1107 
1108 	while (*fmt) {
1109 		const char *old_fmt = fmt;
1110 
1111 		read = format_decode(fmt, &spec);
1112 
1113 		fmt += read;
1114 
1115 		switch (spec.type) {
1116 		case FORMAT_TYPE_NONE: {
1117 			int copy = read;
1118 			if (str < end) {
1119 				if (copy > end - str)
1120 					copy = end - str;
1121 				memcpy(str, old_fmt, copy);
1122 			}
1123 			str += read;
1124 			break;
1125 		}
1126 
1127 		case FORMAT_TYPE_WIDTH:
1128 			spec.field_width = va_arg(args, int);
1129 			break;
1130 
1131 		case FORMAT_TYPE_PRECISION:
1132 			spec.precision = va_arg(args, int);
1133 			break;
1134 
1135 		case FORMAT_TYPE_CHAR:
1136 			if (!(spec.flags & LEFT)) {
1137 				while (--spec.field_width > 0) {
1138 					if (str < end)
1139 						*str = ' ';
1140 					++str;
1141 
1142 				}
1143 			}
1144 			c = (unsigned char) va_arg(args, int);
1145 			if (str < end)
1146 				*str = c;
1147 			++str;
1148 			while (--spec.field_width > 0) {
1149 				if (str < end)
1150 					*str = ' ';
1151 				++str;
1152 			}
1153 			break;
1154 
1155 		case FORMAT_TYPE_STR:
1156 			str = string(str, end, va_arg(args, char *), spec);
1157 			break;
1158 
1159 		case FORMAT_TYPE_PTR:
1160 			str = pointer(fmt+1, str, end, va_arg(args, void *),
1161 				      spec);
1162 			while (isalnum(*fmt))
1163 				fmt++;
1164 			break;
1165 
1166 		case FORMAT_TYPE_PERCENT_CHAR:
1167 			if (str < end)
1168 				*str = '%';
1169 			++str;
1170 			break;
1171 
1172 		case FORMAT_TYPE_INVALID:
1173 			if (str < end)
1174 				*str = '%';
1175 			++str;
1176 			break;
1177 
1178 		case FORMAT_TYPE_NRCHARS: {
1179 			int qualifier = spec.qualifier;
1180 
1181 			if (qualifier == 'l') {
1182 				long *ip = va_arg(args, long *);
1183 				*ip = (str - buf);
1184 			} else if (qualifier == 'Z' ||
1185 					qualifier == 'z') {
1186 				size_t *ip = va_arg(args, size_t *);
1187 				*ip = (str - buf);
1188 			} else {
1189 				int *ip = va_arg(args, int *);
1190 				*ip = (str - buf);
1191 			}
1192 			break;
1193 		}
1194 
1195 		default:
1196 			switch (spec.type) {
1197 			case FORMAT_TYPE_LONG_LONG:
1198 				num = va_arg(args, long long);
1199 				break;
1200 			case FORMAT_TYPE_ULONG:
1201 				num = va_arg(args, unsigned long);
1202 				break;
1203 			case FORMAT_TYPE_LONG:
1204 				num = va_arg(args, long);
1205 				break;
1206 			case FORMAT_TYPE_SIZE_T:
1207 				num = va_arg(args, size_t);
1208 				break;
1209 			case FORMAT_TYPE_PTRDIFF:
1210 				num = va_arg(args, ptrdiff_t);
1211 				break;
1212 			case FORMAT_TYPE_UBYTE:
1213 				num = (unsigned char) va_arg(args, int);
1214 				break;
1215 			case FORMAT_TYPE_BYTE:
1216 				num = (signed char) va_arg(args, int);
1217 				break;
1218 			case FORMAT_TYPE_USHORT:
1219 				num = (unsigned short) va_arg(args, int);
1220 				break;
1221 			case FORMAT_TYPE_SHORT:
1222 				num = (short) va_arg(args, int);
1223 				break;
1224 			case FORMAT_TYPE_INT:
1225 				num = (int) va_arg(args, int);
1226 				break;
1227 			default:
1228 				num = va_arg(args, unsigned int);
1229 			}
1230 
1231 			str = number(str, end, num, spec);
1232 		}
1233 	}
1234 
1235 	if (size > 0) {
1236 		if (str < end)
1237 			*str = '\0';
1238 		else
1239 			end[-1] = '\0';
1240 	}
1241 
1242 	/* the trailing null byte doesn't count towards the total */
1243 	return str-buf;
1244 
1245 }
1246 EXPORT_SYMBOL(vsnprintf);
1247 
1248 /**
1249  * vscnprintf - Format a string and place it in a buffer
1250  * @buf: The buffer to place the result into
1251  * @size: The size of the buffer, including the trailing null space
1252  * @fmt: The format string to use
1253  * @args: Arguments for the format string
1254  *
1255  * The return value is the number of characters which have been written into
1256  * the @buf not including the trailing '\0'. If @size is <= 0 the function
1257  * returns 0.
1258  *
1259  * Call this function if you are already dealing with a va_list.
1260  * You probably want scnprintf() instead.
1261  *
1262  * See the vsnprintf() documentation for format string extensions over C99.
1263  */
1264 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1265 {
1266 	int i;
1267 
1268 	i=vsnprintf(buf,size,fmt,args);
1269 	return (i >= size) ? (size - 1) : i;
1270 }
1271 EXPORT_SYMBOL(vscnprintf);
1272 
1273 /**
1274  * snprintf - Format a string and place it in a buffer
1275  * @buf: The buffer to place the result into
1276  * @size: The size of the buffer, including the trailing null space
1277  * @fmt: The format string to use
1278  * @...: Arguments for the format string
1279  *
1280  * The return value is the number of characters which would be
1281  * generated for the given input, excluding the trailing null,
1282  * as per ISO C99.  If the return is greater than or equal to
1283  * @size, the resulting string is truncated.
1284  *
1285  * See the vsnprintf() documentation for format string extensions over C99.
1286  */
1287 int snprintf(char * buf, size_t size, const char *fmt, ...)
1288 {
1289 	va_list args;
1290 	int i;
1291 
1292 	va_start(args, fmt);
1293 	i=vsnprintf(buf,size,fmt,args);
1294 	va_end(args);
1295 	return i;
1296 }
1297 EXPORT_SYMBOL(snprintf);
1298 
1299 /**
1300  * scnprintf - Format a string and place it in a buffer
1301  * @buf: The buffer to place the result into
1302  * @size: The size of the buffer, including the trailing null space
1303  * @fmt: The format string to use
1304  * @...: Arguments for the format string
1305  *
1306  * The return value is the number of characters written into @buf not including
1307  * the trailing '\0'. If @size is <= 0 the function returns 0.
1308  */
1309 
1310 int scnprintf(char * buf, size_t size, const char *fmt, ...)
1311 {
1312 	va_list args;
1313 	int i;
1314 
1315 	va_start(args, fmt);
1316 	i = vsnprintf(buf, size, fmt, args);
1317 	va_end(args);
1318 	return (i >= size) ? (size - 1) : i;
1319 }
1320 EXPORT_SYMBOL(scnprintf);
1321 
1322 /**
1323  * vsprintf - Format a string and place it in a buffer
1324  * @buf: The buffer to place the result into
1325  * @fmt: The format string to use
1326  * @args: Arguments for the format string
1327  *
1328  * The function returns the number of characters written
1329  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1330  * buffer overflows.
1331  *
1332  * Call this function if you are already dealing with a va_list.
1333  * You probably want sprintf() instead.
1334  *
1335  * See the vsnprintf() documentation for format string extensions over C99.
1336  */
1337 int vsprintf(char *buf, const char *fmt, va_list args)
1338 {
1339 	return vsnprintf(buf, INT_MAX, fmt, args);
1340 }
1341 EXPORT_SYMBOL(vsprintf);
1342 
1343 /**
1344  * sprintf - Format a string and place it in a buffer
1345  * @buf: The buffer to place the result into
1346  * @fmt: The format string to use
1347  * @...: Arguments for the format string
1348  *
1349  * The function returns the number of characters written
1350  * into @buf. Use snprintf() or scnprintf() in order to avoid
1351  * buffer overflows.
1352  *
1353  * See the vsnprintf() documentation for format string extensions over C99.
1354  */
1355 int sprintf(char * buf, const char *fmt, ...)
1356 {
1357 	va_list args;
1358 	int i;
1359 
1360 	va_start(args, fmt);
1361 	i=vsnprintf(buf, INT_MAX, fmt, args);
1362 	va_end(args);
1363 	return i;
1364 }
1365 EXPORT_SYMBOL(sprintf);
1366 
1367 #ifdef CONFIG_BINARY_PRINTF
1368 /*
1369  * bprintf service:
1370  * vbin_printf() - VA arguments to binary data
1371  * bstr_printf() - Binary data to text string
1372  */
1373 
1374 /**
1375  * vbin_printf - Parse a format string and place args' binary value in a buffer
1376  * @bin_buf: The buffer to place args' binary value
1377  * @size: The size of the buffer(by words(32bits), not characters)
1378  * @fmt: The format string to use
1379  * @args: Arguments for the format string
1380  *
1381  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1382  * is skiped.
1383  *
1384  * The return value is the number of words(32bits) which would be generated for
1385  * the given input.
1386  *
1387  * NOTE:
1388  * If the return value is greater than @size, the resulting bin_buf is NOT
1389  * valid for bstr_printf().
1390  */
1391 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1392 {
1393 	struct printf_spec spec = {0};
1394 	char *str, *end;
1395 	int read;
1396 
1397 	str = (char *)bin_buf;
1398 	end = (char *)(bin_buf + size);
1399 
1400 #define save_arg(type)							\
1401 do {									\
1402 	if (sizeof(type) == 8) {					\
1403 		unsigned long long value;				\
1404 		str = PTR_ALIGN(str, sizeof(u32));			\
1405 		value = va_arg(args, unsigned long long);		\
1406 		if (str + sizeof(type) <= end) {			\
1407 			*(u32 *)str = *(u32 *)&value;			\
1408 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
1409 		}							\
1410 	} else {							\
1411 		unsigned long value;					\
1412 		str = PTR_ALIGN(str, sizeof(type));			\
1413 		value = va_arg(args, int);				\
1414 		if (str + sizeof(type) <= end)				\
1415 			*(typeof(type) *)str = (type)value;		\
1416 	}								\
1417 	str += sizeof(type);						\
1418 } while (0)
1419 
1420 
1421 	while (*fmt) {
1422 		read = format_decode(fmt, &spec);
1423 
1424 		fmt += read;
1425 
1426 		switch (spec.type) {
1427 		case FORMAT_TYPE_NONE:
1428 			break;
1429 
1430 		case FORMAT_TYPE_WIDTH:
1431 		case FORMAT_TYPE_PRECISION:
1432 			save_arg(int);
1433 			break;
1434 
1435 		case FORMAT_TYPE_CHAR:
1436 			save_arg(char);
1437 			break;
1438 
1439 		case FORMAT_TYPE_STR: {
1440 			const char *save_str = va_arg(args, char *);
1441 			size_t len;
1442 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1443 					|| (unsigned long)save_str < PAGE_SIZE)
1444 				save_str = "<NULL>";
1445 			len = strlen(save_str);
1446 			if (str + len + 1 < end)
1447 				memcpy(str, save_str, len + 1);
1448 			str += len + 1;
1449 			break;
1450 		}
1451 
1452 		case FORMAT_TYPE_PTR:
1453 			save_arg(void *);
1454 			/* skip all alphanumeric pointer suffixes */
1455 			while (isalnum(*fmt))
1456 				fmt++;
1457 			break;
1458 
1459 		case FORMAT_TYPE_PERCENT_CHAR:
1460 			break;
1461 
1462 		case FORMAT_TYPE_INVALID:
1463 			break;
1464 
1465 		case FORMAT_TYPE_NRCHARS: {
1466 			/* skip %n 's argument */
1467 			int qualifier = spec.qualifier;
1468 			void *skip_arg;
1469 			if (qualifier == 'l')
1470 				skip_arg = va_arg(args, long *);
1471 			else if (qualifier == 'Z' || qualifier == 'z')
1472 				skip_arg = va_arg(args, size_t *);
1473 			else
1474 				skip_arg = va_arg(args, int *);
1475 			break;
1476 		}
1477 
1478 		default:
1479 			switch (spec.type) {
1480 
1481 			case FORMAT_TYPE_LONG_LONG:
1482 				save_arg(long long);
1483 				break;
1484 			case FORMAT_TYPE_ULONG:
1485 			case FORMAT_TYPE_LONG:
1486 				save_arg(unsigned long);
1487 				break;
1488 			case FORMAT_TYPE_SIZE_T:
1489 				save_arg(size_t);
1490 				break;
1491 			case FORMAT_TYPE_PTRDIFF:
1492 				save_arg(ptrdiff_t);
1493 				break;
1494 			case FORMAT_TYPE_UBYTE:
1495 			case FORMAT_TYPE_BYTE:
1496 				save_arg(char);
1497 				break;
1498 			case FORMAT_TYPE_USHORT:
1499 			case FORMAT_TYPE_SHORT:
1500 				save_arg(short);
1501 				break;
1502 			default:
1503 				save_arg(int);
1504 			}
1505 		}
1506 	}
1507 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1508 
1509 #undef save_arg
1510 }
1511 EXPORT_SYMBOL_GPL(vbin_printf);
1512 
1513 /**
1514  * bstr_printf - Format a string from binary arguments and place it in a buffer
1515  * @buf: The buffer to place the result into
1516  * @size: The size of the buffer, including the trailing null space
1517  * @fmt: The format string to use
1518  * @bin_buf: Binary arguments for the format string
1519  *
1520  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1521  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1522  * a binary buffer that generated by vbin_printf.
1523  *
1524  * The format follows C99 vsnprintf, but has some extensions:
1525  * %pS output the name of a text symbol
1526  * %pF output the name of a function pointer with its offset
1527  * %pf output the name of a function pointer without its offset
1528  * %pR output the address range in a struct resource
1529  * %n is ignored
1530  *
1531  * The return value is the number of characters which would
1532  * be generated for the given input, excluding the trailing
1533  * '\0', as per ISO C99. If you want to have the exact
1534  * number of characters written into @buf as return value
1535  * (not including the trailing '\0'), use vscnprintf(). If the
1536  * return is greater than or equal to @size, the resulting
1537  * string is truncated.
1538  */
1539 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1540 {
1541 	unsigned long long num;
1542 	char *str, *end, c;
1543 	const char *args = (const char *)bin_buf;
1544 
1545 	struct printf_spec spec = {0};
1546 
1547 	if (unlikely((int) size < 0)) {
1548 		/* There can be only one.. */
1549 		static char warn = 1;
1550 		WARN_ON(warn);
1551 		warn = 0;
1552 		return 0;
1553 	}
1554 
1555 	str = buf;
1556 	end = buf + size;
1557 
1558 #define get_arg(type)							\
1559 ({									\
1560 	typeof(type) value;						\
1561 	if (sizeof(type) == 8) {					\
1562 		args = PTR_ALIGN(args, sizeof(u32));			\
1563 		*(u32 *)&value = *(u32 *)args;				\
1564 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
1565 	} else {							\
1566 		args = PTR_ALIGN(args, sizeof(type));			\
1567 		value = *(typeof(type) *)args;				\
1568 	}								\
1569 	args += sizeof(type);						\
1570 	value;								\
1571 })
1572 
1573 	/* Make sure end is always >= buf */
1574 	if (end < buf) {
1575 		end = ((void *)-1);
1576 		size = end - buf;
1577 	}
1578 
1579 	while (*fmt) {
1580 		int read;
1581 		const char *old_fmt = fmt;
1582 
1583 		read = format_decode(fmt, &spec);
1584 
1585 		fmt += read;
1586 
1587 		switch (spec.type) {
1588 		case FORMAT_TYPE_NONE: {
1589 			int copy = read;
1590 			if (str < end) {
1591 				if (copy > end - str)
1592 					copy = end - str;
1593 				memcpy(str, old_fmt, copy);
1594 			}
1595 			str += read;
1596 			break;
1597 		}
1598 
1599 		case FORMAT_TYPE_WIDTH:
1600 			spec.field_width = get_arg(int);
1601 			break;
1602 
1603 		case FORMAT_TYPE_PRECISION:
1604 			spec.precision = get_arg(int);
1605 			break;
1606 
1607 		case FORMAT_TYPE_CHAR:
1608 			if (!(spec.flags & LEFT)) {
1609 				while (--spec.field_width > 0) {
1610 					if (str < end)
1611 						*str = ' ';
1612 					++str;
1613 				}
1614 			}
1615 			c = (unsigned char) get_arg(char);
1616 			if (str < end)
1617 				*str = c;
1618 			++str;
1619 			while (--spec.field_width > 0) {
1620 				if (str < end)
1621 					*str = ' ';
1622 				++str;
1623 			}
1624 			break;
1625 
1626 		case FORMAT_TYPE_STR: {
1627 			const char *str_arg = args;
1628 			size_t len = strlen(str_arg);
1629 			args += len + 1;
1630 			str = string(str, end, (char *)str_arg, spec);
1631 			break;
1632 		}
1633 
1634 		case FORMAT_TYPE_PTR:
1635 			str = pointer(fmt+1, str, end, get_arg(void *), spec);
1636 			while (isalnum(*fmt))
1637 				fmt++;
1638 			break;
1639 
1640 		case FORMAT_TYPE_PERCENT_CHAR:
1641 			if (str < end)
1642 				*str = '%';
1643 			++str;
1644 			break;
1645 
1646 		case FORMAT_TYPE_INVALID:
1647 			if (str < end)
1648 				*str = '%';
1649 			++str;
1650 			break;
1651 
1652 		case FORMAT_TYPE_NRCHARS:
1653 			/* skip */
1654 			break;
1655 
1656 		default:
1657 			switch (spec.type) {
1658 
1659 			case FORMAT_TYPE_LONG_LONG:
1660 				num = get_arg(long long);
1661 				break;
1662 			case FORMAT_TYPE_ULONG:
1663 				num = get_arg(unsigned long);
1664 				break;
1665 			case FORMAT_TYPE_LONG:
1666 				num = get_arg(unsigned long);
1667 				break;
1668 			case FORMAT_TYPE_SIZE_T:
1669 				num = get_arg(size_t);
1670 				break;
1671 			case FORMAT_TYPE_PTRDIFF:
1672 				num = get_arg(ptrdiff_t);
1673 				break;
1674 			case FORMAT_TYPE_UBYTE:
1675 				num = get_arg(unsigned char);
1676 				break;
1677 			case FORMAT_TYPE_BYTE:
1678 				num = get_arg(signed char);
1679 				break;
1680 			case FORMAT_TYPE_USHORT:
1681 				num = get_arg(unsigned short);
1682 				break;
1683 			case FORMAT_TYPE_SHORT:
1684 				num = get_arg(short);
1685 				break;
1686 			case FORMAT_TYPE_UINT:
1687 				num = get_arg(unsigned int);
1688 				break;
1689 			default:
1690 				num = get_arg(int);
1691 			}
1692 
1693 			str = number(str, end, num, spec);
1694 		}
1695 	}
1696 
1697 	if (size > 0) {
1698 		if (str < end)
1699 			*str = '\0';
1700 		else
1701 			end[-1] = '\0';
1702 	}
1703 
1704 #undef get_arg
1705 
1706 	/* the trailing null byte doesn't count towards the total */
1707 	return str - buf;
1708 }
1709 EXPORT_SYMBOL_GPL(bstr_printf);
1710 
1711 /**
1712  * bprintf - Parse a format string and place args' binary value in a buffer
1713  * @bin_buf: The buffer to place args' binary value
1714  * @size: The size of the buffer(by words(32bits), not characters)
1715  * @fmt: The format string to use
1716  * @...: Arguments for the format string
1717  *
1718  * The function returns the number of words(u32) written
1719  * into @bin_buf.
1720  */
1721 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1722 {
1723 	va_list args;
1724 	int ret;
1725 
1726 	va_start(args, fmt);
1727 	ret = vbin_printf(bin_buf, size, fmt, args);
1728 	va_end(args);
1729 	return ret;
1730 }
1731 EXPORT_SYMBOL_GPL(bprintf);
1732 
1733 #endif /* CONFIG_BINARY_PRINTF */
1734 
1735 /**
1736  * vsscanf - Unformat a buffer into a list of arguments
1737  * @buf:	input buffer
1738  * @fmt:	format of buffer
1739  * @args:	arguments
1740  */
1741 int vsscanf(const char * buf, const char * fmt, va_list args)
1742 {
1743 	const char *str = buf;
1744 	char *next;
1745 	char digit;
1746 	int num = 0;
1747 	int qualifier;
1748 	int base;
1749 	int field_width;
1750 	int is_sign = 0;
1751 
1752 	while(*fmt && *str) {
1753 		/* skip any white space in format */
1754 		/* white space in format matchs any amount of
1755 		 * white space, including none, in the input.
1756 		 */
1757 		if (isspace(*fmt)) {
1758 			while (isspace(*fmt))
1759 				++fmt;
1760 			while (isspace(*str))
1761 				++str;
1762 		}
1763 
1764 		/* anything that is not a conversion must match exactly */
1765 		if (*fmt != '%' && *fmt) {
1766 			if (*fmt++ != *str++)
1767 				break;
1768 			continue;
1769 		}
1770 
1771 		if (!*fmt)
1772 			break;
1773 		++fmt;
1774 
1775 		/* skip this conversion.
1776 		 * advance both strings to next white space
1777 		 */
1778 		if (*fmt == '*') {
1779 			while (!isspace(*fmt) && *fmt)
1780 				fmt++;
1781 			while (!isspace(*str) && *str)
1782 				str++;
1783 			continue;
1784 		}
1785 
1786 		/* get field width */
1787 		field_width = -1;
1788 		if (isdigit(*fmt))
1789 			field_width = skip_atoi(&fmt);
1790 
1791 		/* get conversion qualifier */
1792 		qualifier = -1;
1793 		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
1794 		    *fmt == 'Z' || *fmt == 'z') {
1795 			qualifier = *fmt++;
1796 			if (unlikely(qualifier == *fmt)) {
1797 				if (qualifier == 'h') {
1798 					qualifier = 'H';
1799 					fmt++;
1800 				} else if (qualifier == 'l') {
1801 					qualifier = 'L';
1802 					fmt++;
1803 				}
1804 			}
1805 		}
1806 		base = 10;
1807 		is_sign = 0;
1808 
1809 		if (!*fmt || !*str)
1810 			break;
1811 
1812 		switch(*fmt++) {
1813 		case 'c':
1814 		{
1815 			char *s = (char *) va_arg(args,char*);
1816 			if (field_width == -1)
1817 				field_width = 1;
1818 			do {
1819 				*s++ = *str++;
1820 			} while (--field_width > 0 && *str);
1821 			num++;
1822 		}
1823 		continue;
1824 		case 's':
1825 		{
1826 			char *s = (char *) va_arg(args, char *);
1827 			if(field_width == -1)
1828 				field_width = INT_MAX;
1829 			/* first, skip leading white space in buffer */
1830 			while (isspace(*str))
1831 				str++;
1832 
1833 			/* now copy until next white space */
1834 			while (*str && !isspace(*str) && field_width--) {
1835 				*s++ = *str++;
1836 			}
1837 			*s = '\0';
1838 			num++;
1839 		}
1840 		continue;
1841 		case 'n':
1842 			/* return number of characters read so far */
1843 		{
1844 			int *i = (int *)va_arg(args,int*);
1845 			*i = str - buf;
1846 		}
1847 		continue;
1848 		case 'o':
1849 			base = 8;
1850 			break;
1851 		case 'x':
1852 		case 'X':
1853 			base = 16;
1854 			break;
1855 		case 'i':
1856                         base = 0;
1857 		case 'd':
1858 			is_sign = 1;
1859 		case 'u':
1860 			break;
1861 		case '%':
1862 			/* looking for '%' in str */
1863 			if (*str++ != '%')
1864 				return num;
1865 			continue;
1866 		default:
1867 			/* invalid format; stop here */
1868 			return num;
1869 		}
1870 
1871 		/* have some sort of integer conversion.
1872 		 * first, skip white space in buffer.
1873 		 */
1874 		while (isspace(*str))
1875 			str++;
1876 
1877 		digit = *str;
1878 		if (is_sign && digit == '-')
1879 			digit = *(str + 1);
1880 
1881 		if (!digit
1882                     || (base == 16 && !isxdigit(digit))
1883                     || (base == 10 && !isdigit(digit))
1884                     || (base == 8 && (!isdigit(digit) || digit > '7'))
1885                     || (base == 0 && !isdigit(digit)))
1886 				break;
1887 
1888 		switch(qualifier) {
1889 		case 'H':	/* that's 'hh' in format */
1890 			if (is_sign) {
1891 				signed char *s = (signed char *) va_arg(args,signed char *);
1892 				*s = (signed char) simple_strtol(str,&next,base);
1893 			} else {
1894 				unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
1895 				*s = (unsigned char) simple_strtoul(str, &next, base);
1896 			}
1897 			break;
1898 		case 'h':
1899 			if (is_sign) {
1900 				short *s = (short *) va_arg(args,short *);
1901 				*s = (short) simple_strtol(str,&next,base);
1902 			} else {
1903 				unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
1904 				*s = (unsigned short) simple_strtoul(str, &next, base);
1905 			}
1906 			break;
1907 		case 'l':
1908 			if (is_sign) {
1909 				long *l = (long *) va_arg(args,long *);
1910 				*l = simple_strtol(str,&next,base);
1911 			} else {
1912 				unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
1913 				*l = simple_strtoul(str,&next,base);
1914 			}
1915 			break;
1916 		case 'L':
1917 			if (is_sign) {
1918 				long long *l = (long long*) va_arg(args,long long *);
1919 				*l = simple_strtoll(str,&next,base);
1920 			} else {
1921 				unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
1922 				*l = simple_strtoull(str,&next,base);
1923 			}
1924 			break;
1925 		case 'Z':
1926 		case 'z':
1927 		{
1928 			size_t *s = (size_t*) va_arg(args,size_t*);
1929 			*s = (size_t) simple_strtoul(str,&next,base);
1930 		}
1931 		break;
1932 		default:
1933 			if (is_sign) {
1934 				int *i = (int *) va_arg(args, int*);
1935 				*i = (int) simple_strtol(str,&next,base);
1936 			} else {
1937 				unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
1938 				*i = (unsigned int) simple_strtoul(str,&next,base);
1939 			}
1940 			break;
1941 		}
1942 		num++;
1943 
1944 		if (!next)
1945 			break;
1946 		str = next;
1947 	}
1948 
1949 	/*
1950 	 * Now we've come all the way through so either the input string or the
1951 	 * format ended. In the former case, there can be a %n at the current
1952 	 * position in the format that needs to be filled.
1953 	 */
1954 	if (*fmt == '%' && *(fmt + 1) == 'n') {
1955 		int *p = (int *)va_arg(args, int *);
1956 		*p = str - buf;
1957 	}
1958 
1959 	return num;
1960 }
1961 EXPORT_SYMBOL(vsscanf);
1962 
1963 /**
1964  * sscanf - Unformat a buffer into a list of arguments
1965  * @buf:	input buffer
1966  * @fmt:	formatting of buffer
1967  * @...:	resulting arguments
1968  */
1969 int sscanf(const char * buf, const char * fmt, ...)
1970 {
1971 	va_list args;
1972 	int i;
1973 
1974 	va_start(args,fmt);
1975 	i = vsscanf(buf,fmt,args);
1976 	va_end(args);
1977 	return i;
1978 }
1979 EXPORT_SYMBOL(sscanf);
1980