xref: /linux/lib/vsprintf.c (revision 85d37226fb5faaf7bec55df50c2cd029bd6bb3cd)
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 #include "kstrtox.h"
35 
36 /**
37  * simple_strtoull - convert a string to an unsigned long long
38  * @cp: The start of the string
39  * @endp: A pointer to the end of the parsed string will be placed here
40  * @base: The number base to use
41  */
42 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
43 {
44 	unsigned long long result;
45 	unsigned int rv;
46 
47 	cp = _parse_integer_fixup_radix(cp, &base);
48 	rv = _parse_integer(cp, base, &result);
49 	/* FIXME */
50 	cp += (rv & ~KSTRTOX_OVERFLOW);
51 
52 	if (endp)
53 		*endp = (char *)cp;
54 
55 	return result;
56 }
57 EXPORT_SYMBOL(simple_strtoull);
58 
59 /**
60  * simple_strtoul - convert a string to an unsigned long
61  * @cp: The start of the string
62  * @endp: A pointer to the end of the parsed string will be placed here
63  * @base: The number base to use
64  */
65 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
66 {
67 	return simple_strtoull(cp, endp, base);
68 }
69 EXPORT_SYMBOL(simple_strtoul);
70 
71 /**
72  * simple_strtol - convert a string to a signed long
73  * @cp: The start of the string
74  * @endp: A pointer to the end of the parsed string will be placed here
75  * @base: The number base to use
76  */
77 long simple_strtol(const char *cp, char **endp, unsigned int base)
78 {
79 	if (*cp == '-')
80 		return -simple_strtoul(cp + 1, endp, base);
81 
82 	return simple_strtoul(cp, endp, base);
83 }
84 EXPORT_SYMBOL(simple_strtol);
85 
86 /**
87  * simple_strtoll - convert a string to a signed long long
88  * @cp: The start of the string
89  * @endp: A pointer to the end of the parsed string will be placed here
90  * @base: The number base to use
91  */
92 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
93 {
94 	if (*cp == '-')
95 		return -simple_strtoull(cp + 1, endp, base);
96 
97 	return simple_strtoull(cp, endp, base);
98 }
99 EXPORT_SYMBOL(simple_strtoll);
100 
101 static noinline_for_stack
102 int skip_atoi(const char **s)
103 {
104 	int i = 0;
105 
106 	while (isdigit(**s))
107 		i = i*10 + *((*s)++) - '0';
108 
109 	return i;
110 }
111 
112 /* Decimal conversion is by far the most typical, and is used
113  * for /proc and /sys data. This directly impacts e.g. top performance
114  * with many processes running. We optimize it for speed
115  * using code from
116  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
117  * (with permission from the author, Douglas W. Jones). */
118 
119 /* Formats correctly any integer in [0,99999].
120  * Outputs from one to five digits depending on input.
121  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
122 static noinline_for_stack
123 char *put_dec_trunc(char *buf, unsigned q)
124 {
125 	unsigned d3, d2, d1, d0;
126 	d1 = (q>>4) & 0xf;
127 	d2 = (q>>8) & 0xf;
128 	d3 = (q>>12);
129 
130 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
131 	q = (d0 * 0xcd) >> 11;
132 	d0 = d0 - 10*q;
133 	*buf++ = d0 + '0'; /* least significant digit */
134 	d1 = q + 9*d3 + 5*d2 + d1;
135 	if (d1 != 0) {
136 		q = (d1 * 0xcd) >> 11;
137 		d1 = d1 - 10*q;
138 		*buf++ = d1 + '0'; /* next digit */
139 
140 		d2 = q + 2*d2;
141 		if ((d2 != 0) || (d3 != 0)) {
142 			q = (d2 * 0xd) >> 7;
143 			d2 = d2 - 10*q;
144 			*buf++ = d2 + '0'; /* next digit */
145 
146 			d3 = q + 4*d3;
147 			if (d3 != 0) {
148 				q = (d3 * 0xcd) >> 11;
149 				d3 = d3 - 10*q;
150 				*buf++ = d3 + '0';  /* next digit */
151 				if (q != 0)
152 					*buf++ = q + '0'; /* most sign. digit */
153 			}
154 		}
155 	}
156 
157 	return buf;
158 }
159 /* Same with if's removed. Always emits five digits */
160 static noinline_for_stack
161 char *put_dec_full(char *buf, unsigned q)
162 {
163 	/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
164 	/* but anyway, gcc produces better code with full-sized ints */
165 	unsigned d3, d2, d1, d0;
166 	d1 = (q>>4) & 0xf;
167 	d2 = (q>>8) & 0xf;
168 	d3 = (q>>12);
169 
170 	/*
171 	 * Possible ways to approx. divide by 10
172 	 * gcc -O2 replaces multiply with shifts and adds
173 	 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
174 	 * (x * 0x67) >> 10:  1100111
175 	 * (x * 0x34) >> 9:    110100 - same
176 	 * (x * 0x1a) >> 8:     11010 - same
177 	 * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
178 	 */
179 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
180 	q = (d0 * 0xcd) >> 11;
181 	d0 = d0 - 10*q;
182 	*buf++ = d0 + '0';
183 	d1 = q + 9*d3 + 5*d2 + d1;
184 		q = (d1 * 0xcd) >> 11;
185 		d1 = d1 - 10*q;
186 		*buf++ = d1 + '0';
187 
188 		d2 = q + 2*d2;
189 			q = (d2 * 0xd) >> 7;
190 			d2 = d2 - 10*q;
191 			*buf++ = d2 + '0';
192 
193 			d3 = q + 4*d3;
194 				q = (d3 * 0xcd) >> 11; /* - shorter code */
195 				/* q = (d3 * 0x67) >> 10; - would also work */
196 				d3 = d3 - 10*q;
197 				*buf++ = d3 + '0';
198 					*buf++ = q + '0';
199 
200 	return buf;
201 }
202 /* No inlining helps gcc to use registers better */
203 static noinline_for_stack
204 char *put_dec(char *buf, unsigned long long num)
205 {
206 	while (1) {
207 		unsigned rem;
208 		if (num < 100000)
209 			return put_dec_trunc(buf, num);
210 		rem = do_div(num, 100000);
211 		buf = put_dec_full(buf, rem);
212 	}
213 }
214 
215 #define ZEROPAD	1		/* pad with zero */
216 #define SIGN	2		/* unsigned/signed long */
217 #define PLUS	4		/* show plus */
218 #define SPACE	8		/* space if plus */
219 #define LEFT	16		/* left justified */
220 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
221 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
222 
223 enum format_type {
224 	FORMAT_TYPE_NONE, /* Just a string part */
225 	FORMAT_TYPE_WIDTH,
226 	FORMAT_TYPE_PRECISION,
227 	FORMAT_TYPE_CHAR,
228 	FORMAT_TYPE_STR,
229 	FORMAT_TYPE_PTR,
230 	FORMAT_TYPE_PERCENT_CHAR,
231 	FORMAT_TYPE_INVALID,
232 	FORMAT_TYPE_LONG_LONG,
233 	FORMAT_TYPE_ULONG,
234 	FORMAT_TYPE_LONG,
235 	FORMAT_TYPE_UBYTE,
236 	FORMAT_TYPE_BYTE,
237 	FORMAT_TYPE_USHORT,
238 	FORMAT_TYPE_SHORT,
239 	FORMAT_TYPE_UINT,
240 	FORMAT_TYPE_INT,
241 	FORMAT_TYPE_NRCHARS,
242 	FORMAT_TYPE_SIZE_T,
243 	FORMAT_TYPE_PTRDIFF
244 };
245 
246 struct printf_spec {
247 	u8	type;		/* format_type enum */
248 	u8	flags;		/* flags to number() */
249 	u8	base;		/* number base, 8, 10 or 16 only */
250 	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
251 	s16	field_width;	/* width of output field */
252 	s16	precision;	/* # of digits/chars */
253 };
254 
255 static noinline_for_stack
256 char *number(char *buf, char *end, unsigned long long num,
257 	     struct printf_spec spec)
258 {
259 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
260 	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
261 
262 	char tmp[66];
263 	char sign;
264 	char locase;
265 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
266 	int i;
267 
268 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
269 	 * produces same digits or (maybe lowercased) letters */
270 	locase = (spec.flags & SMALL);
271 	if (spec.flags & LEFT)
272 		spec.flags &= ~ZEROPAD;
273 	sign = 0;
274 	if (spec.flags & SIGN) {
275 		if ((signed long long)num < 0) {
276 			sign = '-';
277 			num = -(signed long long)num;
278 			spec.field_width--;
279 		} else if (spec.flags & PLUS) {
280 			sign = '+';
281 			spec.field_width--;
282 		} else if (spec.flags & SPACE) {
283 			sign = ' ';
284 			spec.field_width--;
285 		}
286 	}
287 	if (need_pfx) {
288 		spec.field_width--;
289 		if (spec.base == 16)
290 			spec.field_width--;
291 	}
292 
293 	/* generate full string in tmp[], in reverse order */
294 	i = 0;
295 	if (num == 0)
296 		tmp[i++] = '0';
297 	/* Generic code, for any base:
298 	else do {
299 		tmp[i++] = (digits[do_div(num,base)] | locase);
300 	} while (num != 0);
301 	*/
302 	else if (spec.base != 10) { /* 8 or 16 */
303 		int mask = spec.base - 1;
304 		int shift = 3;
305 
306 		if (spec.base == 16)
307 			shift = 4;
308 		do {
309 			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
310 			num >>= shift;
311 		} while (num);
312 	} else { /* base 10 */
313 		i = put_dec(tmp, num) - tmp;
314 	}
315 
316 	/* printing 100 using %2d gives "100", not "00" */
317 	if (i > spec.precision)
318 		spec.precision = i;
319 	/* leading space padding */
320 	spec.field_width -= spec.precision;
321 	if (!(spec.flags & (ZEROPAD+LEFT))) {
322 		while (--spec.field_width >= 0) {
323 			if (buf < end)
324 				*buf = ' ';
325 			++buf;
326 		}
327 	}
328 	/* sign */
329 	if (sign) {
330 		if (buf < end)
331 			*buf = sign;
332 		++buf;
333 	}
334 	/* "0x" / "0" prefix */
335 	if (need_pfx) {
336 		if (buf < end)
337 			*buf = '0';
338 		++buf;
339 		if (spec.base == 16) {
340 			if (buf < end)
341 				*buf = ('X' | locase);
342 			++buf;
343 		}
344 	}
345 	/* zero or space padding */
346 	if (!(spec.flags & LEFT)) {
347 		char c = (spec.flags & ZEROPAD) ? '0' : ' ';
348 		while (--spec.field_width >= 0) {
349 			if (buf < end)
350 				*buf = c;
351 			++buf;
352 		}
353 	}
354 	/* hmm even more zero padding? */
355 	while (i <= --spec.precision) {
356 		if (buf < end)
357 			*buf = '0';
358 		++buf;
359 	}
360 	/* actual digits of result */
361 	while (--i >= 0) {
362 		if (buf < end)
363 			*buf = tmp[i];
364 		++buf;
365 	}
366 	/* trailing space padding */
367 	while (--spec.field_width >= 0) {
368 		if (buf < end)
369 			*buf = ' ';
370 		++buf;
371 	}
372 
373 	return buf;
374 }
375 
376 static noinline_for_stack
377 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
378 {
379 	int len, i;
380 
381 	if ((unsigned long)s < PAGE_SIZE)
382 		s = "(null)";
383 
384 	len = strnlen(s, spec.precision);
385 
386 	if (!(spec.flags & LEFT)) {
387 		while (len < spec.field_width--) {
388 			if (buf < end)
389 				*buf = ' ';
390 			++buf;
391 		}
392 	}
393 	for (i = 0; i < len; ++i) {
394 		if (buf < end)
395 			*buf = *s;
396 		++buf; ++s;
397 	}
398 	while (len < spec.field_width--) {
399 		if (buf < end)
400 			*buf = ' ';
401 		++buf;
402 	}
403 
404 	return buf;
405 }
406 
407 static noinline_for_stack
408 char *symbol_string(char *buf, char *end, void *ptr,
409 		    struct printf_spec spec, char ext)
410 {
411 	unsigned long value = (unsigned long) ptr;
412 #ifdef CONFIG_KALLSYMS
413 	char sym[KSYM_SYMBOL_LEN];
414 	if (ext == 'B')
415 		sprint_backtrace(sym, value);
416 	else if (ext != 'f' && ext != 's')
417 		sprint_symbol(sym, value);
418 	else
419 		kallsyms_lookup(value, NULL, NULL, NULL, sym);
420 
421 	return string(buf, end, sym, spec);
422 #else
423 	spec.field_width = 2 * sizeof(void *);
424 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
425 	spec.base = 16;
426 
427 	return number(buf, end, value, spec);
428 #endif
429 }
430 
431 static noinline_for_stack
432 char *resource_string(char *buf, char *end, struct resource *res,
433 		      struct printf_spec spec, const char *fmt)
434 {
435 #ifndef IO_RSRC_PRINTK_SIZE
436 #define IO_RSRC_PRINTK_SIZE	6
437 #endif
438 
439 #ifndef MEM_RSRC_PRINTK_SIZE
440 #define MEM_RSRC_PRINTK_SIZE	10
441 #endif
442 	static const struct printf_spec io_spec = {
443 		.base = 16,
444 		.field_width = IO_RSRC_PRINTK_SIZE,
445 		.precision = -1,
446 		.flags = SPECIAL | SMALL | ZEROPAD,
447 	};
448 	static const struct printf_spec mem_spec = {
449 		.base = 16,
450 		.field_width = MEM_RSRC_PRINTK_SIZE,
451 		.precision = -1,
452 		.flags = SPECIAL | SMALL | ZEROPAD,
453 	};
454 	static const struct printf_spec bus_spec = {
455 		.base = 16,
456 		.field_width = 2,
457 		.precision = -1,
458 		.flags = SMALL | ZEROPAD,
459 	};
460 	static const struct printf_spec dec_spec = {
461 		.base = 10,
462 		.precision = -1,
463 		.flags = 0,
464 	};
465 	static const struct printf_spec str_spec = {
466 		.field_width = -1,
467 		.precision = 10,
468 		.flags = LEFT,
469 	};
470 	static const struct printf_spec flag_spec = {
471 		.base = 16,
472 		.precision = -1,
473 		.flags = SPECIAL | SMALL,
474 	};
475 
476 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
477 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
478 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
479 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
480 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
481 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
482 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
483 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
484 
485 	char *p = sym, *pend = sym + sizeof(sym);
486 	int decode = (fmt[0] == 'R') ? 1 : 0;
487 	const struct printf_spec *specp;
488 
489 	*p++ = '[';
490 	if (res->flags & IORESOURCE_IO) {
491 		p = string(p, pend, "io  ", str_spec);
492 		specp = &io_spec;
493 	} else if (res->flags & IORESOURCE_MEM) {
494 		p = string(p, pend, "mem ", str_spec);
495 		specp = &mem_spec;
496 	} else if (res->flags & IORESOURCE_IRQ) {
497 		p = string(p, pend, "irq ", str_spec);
498 		specp = &dec_spec;
499 	} else if (res->flags & IORESOURCE_DMA) {
500 		p = string(p, pend, "dma ", str_spec);
501 		specp = &dec_spec;
502 	} else if (res->flags & IORESOURCE_BUS) {
503 		p = string(p, pend, "bus ", str_spec);
504 		specp = &bus_spec;
505 	} else {
506 		p = string(p, pend, "??? ", str_spec);
507 		specp = &mem_spec;
508 		decode = 0;
509 	}
510 	p = number(p, pend, res->start, *specp);
511 	if (res->start != res->end) {
512 		*p++ = '-';
513 		p = number(p, pend, res->end, *specp);
514 	}
515 	if (decode) {
516 		if (res->flags & IORESOURCE_MEM_64)
517 			p = string(p, pend, " 64bit", str_spec);
518 		if (res->flags & IORESOURCE_PREFETCH)
519 			p = string(p, pend, " pref", str_spec);
520 		if (res->flags & IORESOURCE_WINDOW)
521 			p = string(p, pend, " window", str_spec);
522 		if (res->flags & IORESOURCE_DISABLED)
523 			p = string(p, pend, " disabled", str_spec);
524 	} else {
525 		p = string(p, pend, " flags ", str_spec);
526 		p = number(p, pend, res->flags, flag_spec);
527 	}
528 	*p++ = ']';
529 	*p = '\0';
530 
531 	return string(buf, end, sym, spec);
532 }
533 
534 static noinline_for_stack
535 char *mac_address_string(char *buf, char *end, u8 *addr,
536 			 struct printf_spec spec, const char *fmt)
537 {
538 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
539 	char *p = mac_addr;
540 	int i;
541 	char separator;
542 
543 	if (fmt[1] == 'F') {		/* FDDI canonical format */
544 		separator = '-';
545 	} else {
546 		separator = ':';
547 	}
548 
549 	for (i = 0; i < 6; i++) {
550 		p = hex_byte_pack(p, addr[i]);
551 		if (fmt[0] == 'M' && i != 5)
552 			*p++ = separator;
553 	}
554 	*p = '\0';
555 
556 	return string(buf, end, mac_addr, spec);
557 }
558 
559 static noinline_for_stack
560 char *ip4_string(char *p, const u8 *addr, const char *fmt)
561 {
562 	int i;
563 	bool leading_zeros = (fmt[0] == 'i');
564 	int index;
565 	int step;
566 
567 	switch (fmt[2]) {
568 	case 'h':
569 #ifdef __BIG_ENDIAN
570 		index = 0;
571 		step = 1;
572 #else
573 		index = 3;
574 		step = -1;
575 #endif
576 		break;
577 	case 'l':
578 		index = 3;
579 		step = -1;
580 		break;
581 	case 'n':
582 	case 'b':
583 	default:
584 		index = 0;
585 		step = 1;
586 		break;
587 	}
588 	for (i = 0; i < 4; i++) {
589 		char temp[3];	/* hold each IP quad in reverse order */
590 		int digits = put_dec_trunc(temp, addr[index]) - temp;
591 		if (leading_zeros) {
592 			if (digits < 3)
593 				*p++ = '0';
594 			if (digits < 2)
595 				*p++ = '0';
596 		}
597 		/* reverse the digits in the quad */
598 		while (digits--)
599 			*p++ = temp[digits];
600 		if (i < 3)
601 			*p++ = '.';
602 		index += step;
603 	}
604 	*p = '\0';
605 
606 	return p;
607 }
608 
609 static noinline_for_stack
610 char *ip6_compressed_string(char *p, const char *addr)
611 {
612 	int i, j, range;
613 	unsigned char zerolength[8];
614 	int longest = 1;
615 	int colonpos = -1;
616 	u16 word;
617 	u8 hi, lo;
618 	bool needcolon = false;
619 	bool useIPv4;
620 	struct in6_addr in6;
621 
622 	memcpy(&in6, addr, sizeof(struct in6_addr));
623 
624 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
625 
626 	memset(zerolength, 0, sizeof(zerolength));
627 
628 	if (useIPv4)
629 		range = 6;
630 	else
631 		range = 8;
632 
633 	/* find position of longest 0 run */
634 	for (i = 0; i < range; i++) {
635 		for (j = i; j < range; j++) {
636 			if (in6.s6_addr16[j] != 0)
637 				break;
638 			zerolength[i]++;
639 		}
640 	}
641 	for (i = 0; i < range; i++) {
642 		if (zerolength[i] > longest) {
643 			longest = zerolength[i];
644 			colonpos = i;
645 		}
646 	}
647 	if (longest == 1)		/* don't compress a single 0 */
648 		colonpos = -1;
649 
650 	/* emit address */
651 	for (i = 0; i < range; i++) {
652 		if (i == colonpos) {
653 			if (needcolon || i == 0)
654 				*p++ = ':';
655 			*p++ = ':';
656 			needcolon = false;
657 			i += longest - 1;
658 			continue;
659 		}
660 		if (needcolon) {
661 			*p++ = ':';
662 			needcolon = false;
663 		}
664 		/* hex u16 without leading 0s */
665 		word = ntohs(in6.s6_addr16[i]);
666 		hi = word >> 8;
667 		lo = word & 0xff;
668 		if (hi) {
669 			if (hi > 0x0f)
670 				p = hex_byte_pack(p, hi);
671 			else
672 				*p++ = hex_asc_lo(hi);
673 			p = hex_byte_pack(p, lo);
674 		}
675 		else if (lo > 0x0f)
676 			p = hex_byte_pack(p, lo);
677 		else
678 			*p++ = hex_asc_lo(lo);
679 		needcolon = true;
680 	}
681 
682 	if (useIPv4) {
683 		if (needcolon)
684 			*p++ = ':';
685 		p = ip4_string(p, &in6.s6_addr[12], "I4");
686 	}
687 	*p = '\0';
688 
689 	return p;
690 }
691 
692 static noinline_for_stack
693 char *ip6_string(char *p, const char *addr, const char *fmt)
694 {
695 	int i;
696 
697 	for (i = 0; i < 8; i++) {
698 		p = hex_byte_pack(p, *addr++);
699 		p = hex_byte_pack(p, *addr++);
700 		if (fmt[0] == 'I' && i != 7)
701 			*p++ = ':';
702 	}
703 	*p = '\0';
704 
705 	return p;
706 }
707 
708 static noinline_for_stack
709 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
710 		      struct printf_spec spec, const char *fmt)
711 {
712 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
713 
714 	if (fmt[0] == 'I' && fmt[2] == 'c')
715 		ip6_compressed_string(ip6_addr, addr);
716 	else
717 		ip6_string(ip6_addr, addr, fmt);
718 
719 	return string(buf, end, ip6_addr, spec);
720 }
721 
722 static noinline_for_stack
723 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
724 		      struct printf_spec spec, const char *fmt)
725 {
726 	char ip4_addr[sizeof("255.255.255.255")];
727 
728 	ip4_string(ip4_addr, addr, fmt);
729 
730 	return string(buf, end, ip4_addr, spec);
731 }
732 
733 static noinline_for_stack
734 char *uuid_string(char *buf, char *end, const u8 *addr,
735 		  struct printf_spec spec, const char *fmt)
736 {
737 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
738 	char *p = uuid;
739 	int i;
740 	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
741 	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
742 	const u8 *index = be;
743 	bool uc = false;
744 
745 	switch (*(++fmt)) {
746 	case 'L':
747 		uc = true;		/* fall-through */
748 	case 'l':
749 		index = le;
750 		break;
751 	case 'B':
752 		uc = true;
753 		break;
754 	}
755 
756 	for (i = 0; i < 16; i++) {
757 		p = hex_byte_pack(p, addr[index[i]]);
758 		switch (i) {
759 		case 3:
760 		case 5:
761 		case 7:
762 		case 9:
763 			*p++ = '-';
764 			break;
765 		}
766 	}
767 
768 	*p = 0;
769 
770 	if (uc) {
771 		p = uuid;
772 		do {
773 			*p = toupper(*p);
774 		} while (*(++p));
775 	}
776 
777 	return string(buf, end, uuid, spec);
778 }
779 
780 int kptr_restrict __read_mostly;
781 
782 /*
783  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
784  * by an extra set of alphanumeric characters that are extended format
785  * specifiers.
786  *
787  * Right now we handle:
788  *
789  * - 'F' For symbolic function descriptor pointers with offset
790  * - 'f' For simple symbolic function names without offset
791  * - 'S' For symbolic direct pointers with offset
792  * - 's' For symbolic direct pointers without offset
793  * - 'B' For backtraced symbolic direct pointers with offset
794  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
795  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
796  * - 'M' For a 6-byte MAC address, it prints the address in the
797  *       usual colon-separated hex notation
798  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
799  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
800  *       with a dash-separated hex notation
801  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
802  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
803  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
804  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
805  *       IPv6 omits the colons (01020304...0f)
806  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
807  * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
808  * - 'I6c' for IPv6 addresses printed as specified by
809  *       http://tools.ietf.org/html/rfc5952
810  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
811  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
812  *       Options for %pU are:
813  *         b big endian lower case hex (default)
814  *         B big endian UPPER case hex
815  *         l little endian lower case hex
816  *         L little endian UPPER case hex
817  *           big endian output byte order is:
818  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
819  *           little endian output byte order is:
820  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
821  * - 'V' For a struct va_format which contains a format string * and va_list *,
822  *       call vsnprintf(->format, *->va_list).
823  *       Implements a "recursive vsnprintf".
824  *       Do not use this feature without some mechanism to verify the
825  *       correctness of the format string and va_list arguments.
826  * - 'K' For a kernel pointer that should be hidden from unprivileged users
827  *
828  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
829  * function pointers are really function descriptors, which contain a
830  * pointer to the real address.
831  */
832 static noinline_for_stack
833 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
834 	      struct printf_spec spec)
835 {
836 	if (!ptr && *fmt != 'K') {
837 		/*
838 		 * Print (null) with the same width as a pointer so it makes
839 		 * tabular output look nice.
840 		 */
841 		if (spec.field_width == -1)
842 			spec.field_width = 2 * sizeof(void *);
843 		return string(buf, end, "(null)", spec);
844 	}
845 
846 	switch (*fmt) {
847 	case 'F':
848 	case 'f':
849 		ptr = dereference_function_descriptor(ptr);
850 		/* Fallthrough */
851 	case 'S':
852 	case 's':
853 	case 'B':
854 		return symbol_string(buf, end, ptr, spec, *fmt);
855 	case 'R':
856 	case 'r':
857 		return resource_string(buf, end, ptr, spec, fmt);
858 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
859 	case 'm':			/* Contiguous: 000102030405 */
860 					/* [mM]F (FDDI, bit reversed) */
861 		return mac_address_string(buf, end, ptr, spec, fmt);
862 	case 'I':			/* Formatted IP supported
863 					 * 4:	1.2.3.4
864 					 * 6:	0001:0203:...:0708
865 					 * 6c:	1::708 or 1::1.2.3.4
866 					 */
867 	case 'i':			/* Contiguous:
868 					 * 4:	001.002.003.004
869 					 * 6:   000102...0f
870 					 */
871 		switch (fmt[1]) {
872 		case '6':
873 			return ip6_addr_string(buf, end, ptr, spec, fmt);
874 		case '4':
875 			return ip4_addr_string(buf, end, ptr, spec, fmt);
876 		}
877 		break;
878 	case 'U':
879 		return uuid_string(buf, end, ptr, spec, fmt);
880 	case 'V':
881 		return buf + vsnprintf(buf, end > buf ? end - buf : 0,
882 				       ((struct va_format *)ptr)->fmt,
883 				       *(((struct va_format *)ptr)->va));
884 	case 'K':
885 		/*
886 		 * %pK cannot be used in IRQ context because its test
887 		 * for CAP_SYSLOG would be meaningless.
888 		 */
889 		if (in_irq() || in_serving_softirq() || in_nmi()) {
890 			if (spec.field_width == -1)
891 				spec.field_width = 2 * sizeof(void *);
892 			return string(buf, end, "pK-error", spec);
893 		}
894 		if (!((kptr_restrict == 0) ||
895 		      (kptr_restrict == 1 &&
896 		       has_capability_noaudit(current, CAP_SYSLOG))))
897 			ptr = NULL;
898 		break;
899 	}
900 	spec.flags |= SMALL;
901 	if (spec.field_width == -1) {
902 		spec.field_width = 2 * sizeof(void *);
903 		spec.flags |= ZEROPAD;
904 	}
905 	spec.base = 16;
906 
907 	return number(buf, end, (unsigned long) ptr, spec);
908 }
909 
910 /*
911  * Helper function to decode printf style format.
912  * Each call decode a token from the format and return the
913  * number of characters read (or likely the delta where it wants
914  * to go on the next call).
915  * The decoded token is returned through the parameters
916  *
917  * 'h', 'l', or 'L' for integer fields
918  * 'z' support added 23/7/1999 S.H.
919  * 'z' changed to 'Z' --davidm 1/25/99
920  * 't' added for ptrdiff_t
921  *
922  * @fmt: the format string
923  * @type of the token returned
924  * @flags: various flags such as +, -, # tokens..
925  * @field_width: overwritten width
926  * @base: base of the number (octal, hex, ...)
927  * @precision: precision of a number
928  * @qualifier: qualifier of a number (long, size_t, ...)
929  */
930 static noinline_for_stack
931 int format_decode(const char *fmt, struct printf_spec *spec)
932 {
933 	const char *start = fmt;
934 
935 	/* we finished early by reading the field width */
936 	if (spec->type == FORMAT_TYPE_WIDTH) {
937 		if (spec->field_width < 0) {
938 			spec->field_width = -spec->field_width;
939 			spec->flags |= LEFT;
940 		}
941 		spec->type = FORMAT_TYPE_NONE;
942 		goto precision;
943 	}
944 
945 	/* we finished early by reading the precision */
946 	if (spec->type == FORMAT_TYPE_PRECISION) {
947 		if (spec->precision < 0)
948 			spec->precision = 0;
949 
950 		spec->type = FORMAT_TYPE_NONE;
951 		goto qualifier;
952 	}
953 
954 	/* By default */
955 	spec->type = FORMAT_TYPE_NONE;
956 
957 	for (; *fmt ; ++fmt) {
958 		if (*fmt == '%')
959 			break;
960 	}
961 
962 	/* Return the current non-format string */
963 	if (fmt != start || !*fmt)
964 		return fmt - start;
965 
966 	/* Process flags */
967 	spec->flags = 0;
968 
969 	while (1) { /* this also skips first '%' */
970 		bool found = true;
971 
972 		++fmt;
973 
974 		switch (*fmt) {
975 		case '-': spec->flags |= LEFT;    break;
976 		case '+': spec->flags |= PLUS;    break;
977 		case ' ': spec->flags |= SPACE;   break;
978 		case '#': spec->flags |= SPECIAL; break;
979 		case '0': spec->flags |= ZEROPAD; break;
980 		default:  found = false;
981 		}
982 
983 		if (!found)
984 			break;
985 	}
986 
987 	/* get field width */
988 	spec->field_width = -1;
989 
990 	if (isdigit(*fmt))
991 		spec->field_width = skip_atoi(&fmt);
992 	else if (*fmt == '*') {
993 		/* it's the next argument */
994 		spec->type = FORMAT_TYPE_WIDTH;
995 		return ++fmt - start;
996 	}
997 
998 precision:
999 	/* get the precision */
1000 	spec->precision = -1;
1001 	if (*fmt == '.') {
1002 		++fmt;
1003 		if (isdigit(*fmt)) {
1004 			spec->precision = skip_atoi(&fmt);
1005 			if (spec->precision < 0)
1006 				spec->precision = 0;
1007 		} else if (*fmt == '*') {
1008 			/* it's the next argument */
1009 			spec->type = FORMAT_TYPE_PRECISION;
1010 			return ++fmt - start;
1011 		}
1012 	}
1013 
1014 qualifier:
1015 	/* get the conversion qualifier */
1016 	spec->qualifier = -1;
1017 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1018 	    _tolower(*fmt) == 'z' || *fmt == 't') {
1019 		spec->qualifier = *fmt++;
1020 		if (unlikely(spec->qualifier == *fmt)) {
1021 			if (spec->qualifier == 'l') {
1022 				spec->qualifier = 'L';
1023 				++fmt;
1024 			} else if (spec->qualifier == 'h') {
1025 				spec->qualifier = 'H';
1026 				++fmt;
1027 			}
1028 		}
1029 	}
1030 
1031 	/* default base */
1032 	spec->base = 10;
1033 	switch (*fmt) {
1034 	case 'c':
1035 		spec->type = FORMAT_TYPE_CHAR;
1036 		return ++fmt - start;
1037 
1038 	case 's':
1039 		spec->type = FORMAT_TYPE_STR;
1040 		return ++fmt - start;
1041 
1042 	case 'p':
1043 		spec->type = FORMAT_TYPE_PTR;
1044 		return fmt - start;
1045 		/* skip alnum */
1046 
1047 	case 'n':
1048 		spec->type = FORMAT_TYPE_NRCHARS;
1049 		return ++fmt - start;
1050 
1051 	case '%':
1052 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1053 		return ++fmt - start;
1054 
1055 	/* integer number formats - set up the flags and "break" */
1056 	case 'o':
1057 		spec->base = 8;
1058 		break;
1059 
1060 	case 'x':
1061 		spec->flags |= SMALL;
1062 
1063 	case 'X':
1064 		spec->base = 16;
1065 		break;
1066 
1067 	case 'd':
1068 	case 'i':
1069 		spec->flags |= SIGN;
1070 	case 'u':
1071 		break;
1072 
1073 	default:
1074 		spec->type = FORMAT_TYPE_INVALID;
1075 		return fmt - start;
1076 	}
1077 
1078 	if (spec->qualifier == 'L')
1079 		spec->type = FORMAT_TYPE_LONG_LONG;
1080 	else if (spec->qualifier == 'l') {
1081 		if (spec->flags & SIGN)
1082 			spec->type = FORMAT_TYPE_LONG;
1083 		else
1084 			spec->type = FORMAT_TYPE_ULONG;
1085 	} else if (_tolower(spec->qualifier) == 'z') {
1086 		spec->type = FORMAT_TYPE_SIZE_T;
1087 	} else if (spec->qualifier == 't') {
1088 		spec->type = FORMAT_TYPE_PTRDIFF;
1089 	} else if (spec->qualifier == 'H') {
1090 		if (spec->flags & SIGN)
1091 			spec->type = FORMAT_TYPE_BYTE;
1092 		else
1093 			spec->type = FORMAT_TYPE_UBYTE;
1094 	} else if (spec->qualifier == 'h') {
1095 		if (spec->flags & SIGN)
1096 			spec->type = FORMAT_TYPE_SHORT;
1097 		else
1098 			spec->type = FORMAT_TYPE_USHORT;
1099 	} else {
1100 		if (spec->flags & SIGN)
1101 			spec->type = FORMAT_TYPE_INT;
1102 		else
1103 			spec->type = FORMAT_TYPE_UINT;
1104 	}
1105 
1106 	return ++fmt - start;
1107 }
1108 
1109 /**
1110  * vsnprintf - Format a string and place it in a buffer
1111  * @buf: The buffer to place the result into
1112  * @size: The size of the buffer, including the trailing null space
1113  * @fmt: The format string to use
1114  * @args: Arguments for the format string
1115  *
1116  * This function follows C99 vsnprintf, but has some extensions:
1117  * %pS output the name of a text symbol with offset
1118  * %ps output the name of a text symbol without offset
1119  * %pF output the name of a function pointer with its offset
1120  * %pf output the name of a function pointer without its offset
1121  * %pB output the name of a backtrace symbol with its offset
1122  * %pR output the address range in a struct resource with decoded flags
1123  * %pr output the address range in a struct resource with raw flags
1124  * %pM output a 6-byte MAC address with colons
1125  * %pm output a 6-byte MAC address without colons
1126  * %pI4 print an IPv4 address without leading zeros
1127  * %pi4 print an IPv4 address with leading zeros
1128  * %pI6 print an IPv6 address with colons
1129  * %pi6 print an IPv6 address without colons
1130  * %pI6c print an IPv6 address as specified by RFC 5952
1131  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1132  *   case.
1133  * %n is ignored
1134  *
1135  * The return value is the number of characters which would
1136  * be generated for the given input, excluding the trailing
1137  * '\0', as per ISO C99. If you want to have the exact
1138  * number of characters written into @buf as return value
1139  * (not including the trailing '\0'), use vscnprintf(). If the
1140  * return is greater than or equal to @size, the resulting
1141  * string is truncated.
1142  *
1143  * If you're not already dealing with a va_list consider using snprintf().
1144  */
1145 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1146 {
1147 	unsigned long long num;
1148 	char *str, *end;
1149 	struct printf_spec spec = {0};
1150 
1151 	/* Reject out-of-range values early.  Large positive sizes are
1152 	   used for unknown buffer sizes. */
1153 	if (WARN_ON_ONCE((int) size < 0))
1154 		return 0;
1155 
1156 	str = buf;
1157 	end = buf + size;
1158 
1159 	/* Make sure end is always >= buf */
1160 	if (end < buf) {
1161 		end = ((void *)-1);
1162 		size = end - buf;
1163 	}
1164 
1165 	while (*fmt) {
1166 		const char *old_fmt = fmt;
1167 		int read = format_decode(fmt, &spec);
1168 
1169 		fmt += read;
1170 
1171 		switch (spec.type) {
1172 		case FORMAT_TYPE_NONE: {
1173 			int copy = read;
1174 			if (str < end) {
1175 				if (copy > end - str)
1176 					copy = end - str;
1177 				memcpy(str, old_fmt, copy);
1178 			}
1179 			str += read;
1180 			break;
1181 		}
1182 
1183 		case FORMAT_TYPE_WIDTH:
1184 			spec.field_width = va_arg(args, int);
1185 			break;
1186 
1187 		case FORMAT_TYPE_PRECISION:
1188 			spec.precision = va_arg(args, int);
1189 			break;
1190 
1191 		case FORMAT_TYPE_CHAR: {
1192 			char c;
1193 
1194 			if (!(spec.flags & LEFT)) {
1195 				while (--spec.field_width > 0) {
1196 					if (str < end)
1197 						*str = ' ';
1198 					++str;
1199 
1200 				}
1201 			}
1202 			c = (unsigned char) va_arg(args, int);
1203 			if (str < end)
1204 				*str = c;
1205 			++str;
1206 			while (--spec.field_width > 0) {
1207 				if (str < end)
1208 					*str = ' ';
1209 				++str;
1210 			}
1211 			break;
1212 		}
1213 
1214 		case FORMAT_TYPE_STR:
1215 			str = string(str, end, va_arg(args, char *), spec);
1216 			break;
1217 
1218 		case FORMAT_TYPE_PTR:
1219 			str = pointer(fmt+1, str, end, va_arg(args, void *),
1220 				      spec);
1221 			while (isalnum(*fmt))
1222 				fmt++;
1223 			break;
1224 
1225 		case FORMAT_TYPE_PERCENT_CHAR:
1226 			if (str < end)
1227 				*str = '%';
1228 			++str;
1229 			break;
1230 
1231 		case FORMAT_TYPE_INVALID:
1232 			if (str < end)
1233 				*str = '%';
1234 			++str;
1235 			break;
1236 
1237 		case FORMAT_TYPE_NRCHARS: {
1238 			u8 qualifier = spec.qualifier;
1239 
1240 			if (qualifier == 'l') {
1241 				long *ip = va_arg(args, long *);
1242 				*ip = (str - buf);
1243 			} else if (_tolower(qualifier) == 'z') {
1244 				size_t *ip = va_arg(args, size_t *);
1245 				*ip = (str - buf);
1246 			} else {
1247 				int *ip = va_arg(args, int *);
1248 				*ip = (str - buf);
1249 			}
1250 			break;
1251 		}
1252 
1253 		default:
1254 			switch (spec.type) {
1255 			case FORMAT_TYPE_LONG_LONG:
1256 				num = va_arg(args, long long);
1257 				break;
1258 			case FORMAT_TYPE_ULONG:
1259 				num = va_arg(args, unsigned long);
1260 				break;
1261 			case FORMAT_TYPE_LONG:
1262 				num = va_arg(args, long);
1263 				break;
1264 			case FORMAT_TYPE_SIZE_T:
1265 				num = va_arg(args, size_t);
1266 				break;
1267 			case FORMAT_TYPE_PTRDIFF:
1268 				num = va_arg(args, ptrdiff_t);
1269 				break;
1270 			case FORMAT_TYPE_UBYTE:
1271 				num = (unsigned char) va_arg(args, int);
1272 				break;
1273 			case FORMAT_TYPE_BYTE:
1274 				num = (signed char) va_arg(args, int);
1275 				break;
1276 			case FORMAT_TYPE_USHORT:
1277 				num = (unsigned short) va_arg(args, int);
1278 				break;
1279 			case FORMAT_TYPE_SHORT:
1280 				num = (short) va_arg(args, int);
1281 				break;
1282 			case FORMAT_TYPE_INT:
1283 				num = (int) va_arg(args, int);
1284 				break;
1285 			default:
1286 				num = va_arg(args, unsigned int);
1287 			}
1288 
1289 			str = number(str, end, num, spec);
1290 		}
1291 	}
1292 
1293 	if (size > 0) {
1294 		if (str < end)
1295 			*str = '\0';
1296 		else
1297 			end[-1] = '\0';
1298 	}
1299 
1300 	/* the trailing null byte doesn't count towards the total */
1301 	return str-buf;
1302 
1303 }
1304 EXPORT_SYMBOL(vsnprintf);
1305 
1306 /**
1307  * vscnprintf - Format a string and place it in a buffer
1308  * @buf: The buffer to place the result into
1309  * @size: The size of the buffer, including the trailing null space
1310  * @fmt: The format string to use
1311  * @args: Arguments for the format string
1312  *
1313  * The return value is the number of characters which have been written into
1314  * the @buf not including the trailing '\0'. If @size is == 0 the function
1315  * returns 0.
1316  *
1317  * If you're not already dealing with a va_list consider using scnprintf().
1318  *
1319  * See the vsnprintf() documentation for format string extensions over C99.
1320  */
1321 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1322 {
1323 	int i;
1324 
1325 	i = vsnprintf(buf, size, fmt, args);
1326 
1327 	if (likely(i < size))
1328 		return i;
1329 	if (size != 0)
1330 		return size - 1;
1331 	return 0;
1332 }
1333 EXPORT_SYMBOL(vscnprintf);
1334 
1335 /**
1336  * snprintf - Format a string and place it in a buffer
1337  * @buf: The buffer to place the result into
1338  * @size: The size of the buffer, including the trailing null space
1339  * @fmt: The format string to use
1340  * @...: Arguments for the format string
1341  *
1342  * The return value is the number of characters which would be
1343  * generated for the given input, excluding the trailing null,
1344  * as per ISO C99.  If the return is greater than or equal to
1345  * @size, the resulting string is truncated.
1346  *
1347  * See the vsnprintf() documentation for format string extensions over C99.
1348  */
1349 int snprintf(char *buf, size_t size, const char *fmt, ...)
1350 {
1351 	va_list args;
1352 	int i;
1353 
1354 	va_start(args, fmt);
1355 	i = vsnprintf(buf, size, fmt, args);
1356 	va_end(args);
1357 
1358 	return i;
1359 }
1360 EXPORT_SYMBOL(snprintf);
1361 
1362 /**
1363  * scnprintf - Format a string and place it in a buffer
1364  * @buf: The buffer to place the result into
1365  * @size: The size of the buffer, including the trailing null space
1366  * @fmt: The format string to use
1367  * @...: Arguments for the format string
1368  *
1369  * The return value is the number of characters written into @buf not including
1370  * the trailing '\0'. If @size is == 0 the function returns 0.
1371  */
1372 
1373 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1374 {
1375 	va_list args;
1376 	int i;
1377 
1378 	va_start(args, fmt);
1379 	i = vscnprintf(buf, size, fmt, args);
1380 	va_end(args);
1381 
1382 	return i;
1383 }
1384 EXPORT_SYMBOL(scnprintf);
1385 
1386 /**
1387  * vsprintf - Format a string and place it in a buffer
1388  * @buf: The buffer to place the result into
1389  * @fmt: The format string to use
1390  * @args: Arguments for the format string
1391  *
1392  * The function returns the number of characters written
1393  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1394  * buffer overflows.
1395  *
1396  * If you're not already dealing with a va_list consider using sprintf().
1397  *
1398  * See the vsnprintf() documentation for format string extensions over C99.
1399  */
1400 int vsprintf(char *buf, const char *fmt, va_list args)
1401 {
1402 	return vsnprintf(buf, INT_MAX, fmt, args);
1403 }
1404 EXPORT_SYMBOL(vsprintf);
1405 
1406 /**
1407  * sprintf - Format a string and place it in a buffer
1408  * @buf: The buffer to place the result into
1409  * @fmt: The format string to use
1410  * @...: Arguments for the format string
1411  *
1412  * The function returns the number of characters written
1413  * into @buf. Use snprintf() or scnprintf() in order to avoid
1414  * buffer overflows.
1415  *
1416  * See the vsnprintf() documentation for format string extensions over C99.
1417  */
1418 int sprintf(char *buf, const char *fmt, ...)
1419 {
1420 	va_list args;
1421 	int i;
1422 
1423 	va_start(args, fmt);
1424 	i = vsnprintf(buf, INT_MAX, fmt, args);
1425 	va_end(args);
1426 
1427 	return i;
1428 }
1429 EXPORT_SYMBOL(sprintf);
1430 
1431 #ifdef CONFIG_BINARY_PRINTF
1432 /*
1433  * bprintf service:
1434  * vbin_printf() - VA arguments to binary data
1435  * bstr_printf() - Binary data to text string
1436  */
1437 
1438 /**
1439  * vbin_printf - Parse a format string and place args' binary value in a buffer
1440  * @bin_buf: The buffer to place args' binary value
1441  * @size: The size of the buffer(by words(32bits), not characters)
1442  * @fmt: The format string to use
1443  * @args: Arguments for the format string
1444  *
1445  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1446  * is skiped.
1447  *
1448  * The return value is the number of words(32bits) which would be generated for
1449  * the given input.
1450  *
1451  * NOTE:
1452  * If the return value is greater than @size, the resulting bin_buf is NOT
1453  * valid for bstr_printf().
1454  */
1455 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1456 {
1457 	struct printf_spec spec = {0};
1458 	char *str, *end;
1459 
1460 	str = (char *)bin_buf;
1461 	end = (char *)(bin_buf + size);
1462 
1463 #define save_arg(type)							\
1464 do {									\
1465 	if (sizeof(type) == 8) {					\
1466 		unsigned long long value;				\
1467 		str = PTR_ALIGN(str, sizeof(u32));			\
1468 		value = va_arg(args, unsigned long long);		\
1469 		if (str + sizeof(type) <= end) {			\
1470 			*(u32 *)str = *(u32 *)&value;			\
1471 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
1472 		}							\
1473 	} else {							\
1474 		unsigned long value;					\
1475 		str = PTR_ALIGN(str, sizeof(type));			\
1476 		value = va_arg(args, int);				\
1477 		if (str + sizeof(type) <= end)				\
1478 			*(typeof(type) *)str = (type)value;		\
1479 	}								\
1480 	str += sizeof(type);						\
1481 } while (0)
1482 
1483 	while (*fmt) {
1484 		int read = format_decode(fmt, &spec);
1485 
1486 		fmt += read;
1487 
1488 		switch (spec.type) {
1489 		case FORMAT_TYPE_NONE:
1490 		case FORMAT_TYPE_INVALID:
1491 		case FORMAT_TYPE_PERCENT_CHAR:
1492 			break;
1493 
1494 		case FORMAT_TYPE_WIDTH:
1495 		case FORMAT_TYPE_PRECISION:
1496 			save_arg(int);
1497 			break;
1498 
1499 		case FORMAT_TYPE_CHAR:
1500 			save_arg(char);
1501 			break;
1502 
1503 		case FORMAT_TYPE_STR: {
1504 			const char *save_str = va_arg(args, char *);
1505 			size_t len;
1506 
1507 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1508 					|| (unsigned long)save_str < PAGE_SIZE)
1509 				save_str = "(null)";
1510 			len = strlen(save_str) + 1;
1511 			if (str + len < end)
1512 				memcpy(str, save_str, len);
1513 			str += len;
1514 			break;
1515 		}
1516 
1517 		case FORMAT_TYPE_PTR:
1518 			save_arg(void *);
1519 			/* skip all alphanumeric pointer suffixes */
1520 			while (isalnum(*fmt))
1521 				fmt++;
1522 			break;
1523 
1524 		case FORMAT_TYPE_NRCHARS: {
1525 			/* skip %n 's argument */
1526 			u8 qualifier = spec.qualifier;
1527 			void *skip_arg;
1528 			if (qualifier == 'l')
1529 				skip_arg = va_arg(args, long *);
1530 			else if (_tolower(qualifier) == 'z')
1531 				skip_arg = va_arg(args, size_t *);
1532 			else
1533 				skip_arg = va_arg(args, int *);
1534 			break;
1535 		}
1536 
1537 		default:
1538 			switch (spec.type) {
1539 
1540 			case FORMAT_TYPE_LONG_LONG:
1541 				save_arg(long long);
1542 				break;
1543 			case FORMAT_TYPE_ULONG:
1544 			case FORMAT_TYPE_LONG:
1545 				save_arg(unsigned long);
1546 				break;
1547 			case FORMAT_TYPE_SIZE_T:
1548 				save_arg(size_t);
1549 				break;
1550 			case FORMAT_TYPE_PTRDIFF:
1551 				save_arg(ptrdiff_t);
1552 				break;
1553 			case FORMAT_TYPE_UBYTE:
1554 			case FORMAT_TYPE_BYTE:
1555 				save_arg(char);
1556 				break;
1557 			case FORMAT_TYPE_USHORT:
1558 			case FORMAT_TYPE_SHORT:
1559 				save_arg(short);
1560 				break;
1561 			default:
1562 				save_arg(int);
1563 			}
1564 		}
1565 	}
1566 
1567 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1568 #undef save_arg
1569 }
1570 EXPORT_SYMBOL_GPL(vbin_printf);
1571 
1572 /**
1573  * bstr_printf - Format a string from binary arguments and place it in a buffer
1574  * @buf: The buffer to place the result into
1575  * @size: The size of the buffer, including the trailing null space
1576  * @fmt: The format string to use
1577  * @bin_buf: Binary arguments for the format string
1578  *
1579  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1580  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1581  * a binary buffer that generated by vbin_printf.
1582  *
1583  * The format follows C99 vsnprintf, but has some extensions:
1584  *  see vsnprintf comment for details.
1585  *
1586  * The return value is the number of characters which would
1587  * be generated for the given input, excluding the trailing
1588  * '\0', as per ISO C99. If you want to have the exact
1589  * number of characters written into @buf as return value
1590  * (not including the trailing '\0'), use vscnprintf(). If the
1591  * return is greater than or equal to @size, the resulting
1592  * string is truncated.
1593  */
1594 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1595 {
1596 	struct printf_spec spec = {0};
1597 	char *str, *end;
1598 	const char *args = (const char *)bin_buf;
1599 
1600 	if (WARN_ON_ONCE((int) size < 0))
1601 		return 0;
1602 
1603 	str = buf;
1604 	end = buf + size;
1605 
1606 #define get_arg(type)							\
1607 ({									\
1608 	typeof(type) value;						\
1609 	if (sizeof(type) == 8) {					\
1610 		args = PTR_ALIGN(args, sizeof(u32));			\
1611 		*(u32 *)&value = *(u32 *)args;				\
1612 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
1613 	} else {							\
1614 		args = PTR_ALIGN(args, sizeof(type));			\
1615 		value = *(typeof(type) *)args;				\
1616 	}								\
1617 	args += sizeof(type);						\
1618 	value;								\
1619 })
1620 
1621 	/* Make sure end is always >= buf */
1622 	if (end < buf) {
1623 		end = ((void *)-1);
1624 		size = end - buf;
1625 	}
1626 
1627 	while (*fmt) {
1628 		const char *old_fmt = fmt;
1629 		int read = format_decode(fmt, &spec);
1630 
1631 		fmt += read;
1632 
1633 		switch (spec.type) {
1634 		case FORMAT_TYPE_NONE: {
1635 			int copy = read;
1636 			if (str < end) {
1637 				if (copy > end - str)
1638 					copy = end - str;
1639 				memcpy(str, old_fmt, copy);
1640 			}
1641 			str += read;
1642 			break;
1643 		}
1644 
1645 		case FORMAT_TYPE_WIDTH:
1646 			spec.field_width = get_arg(int);
1647 			break;
1648 
1649 		case FORMAT_TYPE_PRECISION:
1650 			spec.precision = get_arg(int);
1651 			break;
1652 
1653 		case FORMAT_TYPE_CHAR: {
1654 			char c;
1655 
1656 			if (!(spec.flags & LEFT)) {
1657 				while (--spec.field_width > 0) {
1658 					if (str < end)
1659 						*str = ' ';
1660 					++str;
1661 				}
1662 			}
1663 			c = (unsigned char) get_arg(char);
1664 			if (str < end)
1665 				*str = c;
1666 			++str;
1667 			while (--spec.field_width > 0) {
1668 				if (str < end)
1669 					*str = ' ';
1670 				++str;
1671 			}
1672 			break;
1673 		}
1674 
1675 		case FORMAT_TYPE_STR: {
1676 			const char *str_arg = args;
1677 			args += strlen(str_arg) + 1;
1678 			str = string(str, end, (char *)str_arg, spec);
1679 			break;
1680 		}
1681 
1682 		case FORMAT_TYPE_PTR:
1683 			str = pointer(fmt+1, str, end, get_arg(void *), spec);
1684 			while (isalnum(*fmt))
1685 				fmt++;
1686 			break;
1687 
1688 		case FORMAT_TYPE_PERCENT_CHAR:
1689 		case FORMAT_TYPE_INVALID:
1690 			if (str < end)
1691 				*str = '%';
1692 			++str;
1693 			break;
1694 
1695 		case FORMAT_TYPE_NRCHARS:
1696 			/* skip */
1697 			break;
1698 
1699 		default: {
1700 			unsigned long long num;
1701 
1702 			switch (spec.type) {
1703 
1704 			case FORMAT_TYPE_LONG_LONG:
1705 				num = get_arg(long long);
1706 				break;
1707 			case FORMAT_TYPE_ULONG:
1708 			case FORMAT_TYPE_LONG:
1709 				num = get_arg(unsigned long);
1710 				break;
1711 			case FORMAT_TYPE_SIZE_T:
1712 				num = get_arg(size_t);
1713 				break;
1714 			case FORMAT_TYPE_PTRDIFF:
1715 				num = get_arg(ptrdiff_t);
1716 				break;
1717 			case FORMAT_TYPE_UBYTE:
1718 				num = get_arg(unsigned char);
1719 				break;
1720 			case FORMAT_TYPE_BYTE:
1721 				num = get_arg(signed char);
1722 				break;
1723 			case FORMAT_TYPE_USHORT:
1724 				num = get_arg(unsigned short);
1725 				break;
1726 			case FORMAT_TYPE_SHORT:
1727 				num = get_arg(short);
1728 				break;
1729 			case FORMAT_TYPE_UINT:
1730 				num = get_arg(unsigned int);
1731 				break;
1732 			default:
1733 				num = get_arg(int);
1734 			}
1735 
1736 			str = number(str, end, num, spec);
1737 		} /* default: */
1738 		} /* switch(spec.type) */
1739 	} /* while(*fmt) */
1740 
1741 	if (size > 0) {
1742 		if (str < end)
1743 			*str = '\0';
1744 		else
1745 			end[-1] = '\0';
1746 	}
1747 
1748 #undef get_arg
1749 
1750 	/* the trailing null byte doesn't count towards the total */
1751 	return str - buf;
1752 }
1753 EXPORT_SYMBOL_GPL(bstr_printf);
1754 
1755 /**
1756  * bprintf - Parse a format string and place args' binary value in a buffer
1757  * @bin_buf: The buffer to place args' binary value
1758  * @size: The size of the buffer(by words(32bits), not characters)
1759  * @fmt: The format string to use
1760  * @...: Arguments for the format string
1761  *
1762  * The function returns the number of words(u32) written
1763  * into @bin_buf.
1764  */
1765 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1766 {
1767 	va_list args;
1768 	int ret;
1769 
1770 	va_start(args, fmt);
1771 	ret = vbin_printf(bin_buf, size, fmt, args);
1772 	va_end(args);
1773 
1774 	return ret;
1775 }
1776 EXPORT_SYMBOL_GPL(bprintf);
1777 
1778 #endif /* CONFIG_BINARY_PRINTF */
1779 
1780 /**
1781  * vsscanf - Unformat a buffer into a list of arguments
1782  * @buf:	input buffer
1783  * @fmt:	format of buffer
1784  * @args:	arguments
1785  */
1786 int vsscanf(const char *buf, const char *fmt, va_list args)
1787 {
1788 	const char *str = buf;
1789 	char *next;
1790 	char digit;
1791 	int num = 0;
1792 	u8 qualifier;
1793 	u8 base;
1794 	s16 field_width;
1795 	bool is_sign;
1796 
1797 	while (*fmt && *str) {
1798 		/* skip any white space in format */
1799 		/* white space in format matchs any amount of
1800 		 * white space, including none, in the input.
1801 		 */
1802 		if (isspace(*fmt)) {
1803 			fmt = skip_spaces(++fmt);
1804 			str = skip_spaces(str);
1805 		}
1806 
1807 		/* anything that is not a conversion must match exactly */
1808 		if (*fmt != '%' && *fmt) {
1809 			if (*fmt++ != *str++)
1810 				break;
1811 			continue;
1812 		}
1813 
1814 		if (!*fmt)
1815 			break;
1816 		++fmt;
1817 
1818 		/* skip this conversion.
1819 		 * advance both strings to next white space
1820 		 */
1821 		if (*fmt == '*') {
1822 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
1823 				fmt++;
1824 			while (!isspace(*str) && *str)
1825 				str++;
1826 			continue;
1827 		}
1828 
1829 		/* get field width */
1830 		field_width = -1;
1831 		if (isdigit(*fmt))
1832 			field_width = skip_atoi(&fmt);
1833 
1834 		/* get conversion qualifier */
1835 		qualifier = -1;
1836 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1837 		    _tolower(*fmt) == 'z') {
1838 			qualifier = *fmt++;
1839 			if (unlikely(qualifier == *fmt)) {
1840 				if (qualifier == 'h') {
1841 					qualifier = 'H';
1842 					fmt++;
1843 				} else if (qualifier == 'l') {
1844 					qualifier = 'L';
1845 					fmt++;
1846 				}
1847 			}
1848 		}
1849 
1850 		if (!*fmt || !*str)
1851 			break;
1852 
1853 		base = 10;
1854 		is_sign = 0;
1855 
1856 		switch (*fmt++) {
1857 		case 'c':
1858 		{
1859 			char *s = (char *)va_arg(args, char*);
1860 			if (field_width == -1)
1861 				field_width = 1;
1862 			do {
1863 				*s++ = *str++;
1864 			} while (--field_width > 0 && *str);
1865 			num++;
1866 		}
1867 		continue;
1868 		case 's':
1869 		{
1870 			char *s = (char *)va_arg(args, char *);
1871 			if (field_width == -1)
1872 				field_width = SHRT_MAX;
1873 			/* first, skip leading white space in buffer */
1874 			str = skip_spaces(str);
1875 
1876 			/* now copy until next white space */
1877 			while (*str && !isspace(*str) && field_width--)
1878 				*s++ = *str++;
1879 			*s = '\0';
1880 			num++;
1881 		}
1882 		continue;
1883 		case 'n':
1884 			/* return number of characters read so far */
1885 		{
1886 			int *i = (int *)va_arg(args, int*);
1887 			*i = str - buf;
1888 		}
1889 		continue;
1890 		case 'o':
1891 			base = 8;
1892 			break;
1893 		case 'x':
1894 		case 'X':
1895 			base = 16;
1896 			break;
1897 		case 'i':
1898 			base = 0;
1899 		case 'd':
1900 			is_sign = 1;
1901 		case 'u':
1902 			break;
1903 		case '%':
1904 			/* looking for '%' in str */
1905 			if (*str++ != '%')
1906 				return num;
1907 			continue;
1908 		default:
1909 			/* invalid format; stop here */
1910 			return num;
1911 		}
1912 
1913 		/* have some sort of integer conversion.
1914 		 * first, skip white space in buffer.
1915 		 */
1916 		str = skip_spaces(str);
1917 
1918 		digit = *str;
1919 		if (is_sign && digit == '-')
1920 			digit = *(str + 1);
1921 
1922 		if (!digit
1923 		    || (base == 16 && !isxdigit(digit))
1924 		    || (base == 10 && !isdigit(digit))
1925 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
1926 		    || (base == 0 && !isdigit(digit)))
1927 			break;
1928 
1929 		switch (qualifier) {
1930 		case 'H':	/* that's 'hh' in format */
1931 			if (is_sign) {
1932 				signed char *s = (signed char *)va_arg(args, signed char *);
1933 				*s = (signed char)simple_strtol(str, &next, base);
1934 			} else {
1935 				unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
1936 				*s = (unsigned char)simple_strtoul(str, &next, base);
1937 			}
1938 			break;
1939 		case 'h':
1940 			if (is_sign) {
1941 				short *s = (short *)va_arg(args, short *);
1942 				*s = (short)simple_strtol(str, &next, base);
1943 			} else {
1944 				unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
1945 				*s = (unsigned short)simple_strtoul(str, &next, base);
1946 			}
1947 			break;
1948 		case 'l':
1949 			if (is_sign) {
1950 				long *l = (long *)va_arg(args, long *);
1951 				*l = simple_strtol(str, &next, base);
1952 			} else {
1953 				unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
1954 				*l = simple_strtoul(str, &next, base);
1955 			}
1956 			break;
1957 		case 'L':
1958 			if (is_sign) {
1959 				long long *l = (long long *)va_arg(args, long long *);
1960 				*l = simple_strtoll(str, &next, base);
1961 			} else {
1962 				unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
1963 				*l = simple_strtoull(str, &next, base);
1964 			}
1965 			break;
1966 		case 'Z':
1967 		case 'z':
1968 		{
1969 			size_t *s = (size_t *)va_arg(args, size_t *);
1970 			*s = (size_t)simple_strtoul(str, &next, base);
1971 		}
1972 		break;
1973 		default:
1974 			if (is_sign) {
1975 				int *i = (int *)va_arg(args, int *);
1976 				*i = (int)simple_strtol(str, &next, base);
1977 			} else {
1978 				unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
1979 				*i = (unsigned int)simple_strtoul(str, &next, base);
1980 			}
1981 			break;
1982 		}
1983 		num++;
1984 
1985 		if (!next)
1986 			break;
1987 		str = next;
1988 	}
1989 
1990 	/*
1991 	 * Now we've come all the way through so either the input string or the
1992 	 * format ended. In the former case, there can be a %n at the current
1993 	 * position in the format that needs to be filled.
1994 	 */
1995 	if (*fmt == '%' && *(fmt + 1) == 'n') {
1996 		int *p = (int *)va_arg(args, int *);
1997 		*p = str - buf;
1998 	}
1999 
2000 	return num;
2001 }
2002 EXPORT_SYMBOL(vsscanf);
2003 
2004 /**
2005  * sscanf - Unformat a buffer into a list of arguments
2006  * @buf:	input buffer
2007  * @fmt:	formatting of buffer
2008  * @...:	resulting arguments
2009  */
2010 int sscanf(const char *buf, const char *fmt, ...)
2011 {
2012 	va_list args;
2013 	int i;
2014 
2015 	va_start(args, fmt);
2016 	i = vsscanf(buf, fmt, args);
2017 	va_end(args);
2018 
2019 	return i;
2020 }
2021 EXPORT_SYMBOL(sscanf);
2022