xref: /openbmc/linux/lib/vsprintf.c (revision cd5d5810)
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>	/* for KSYM_SYMBOL_LEN */
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/math64.h>
27 #include <linux/uaccess.h>
28 #include <linux/ioport.h>
29 #include <linux/dcache.h>
30 #include <net/addrconf.h>
31 
32 #include <asm/page.h>		/* for PAGE_SIZE */
33 #include <asm/sections.h>	/* for dereference_function_descriptor() */
34 
35 #include "kstrtox.h"
36 
37 /**
38  * simple_strtoull - convert a string to an unsigned long long
39  * @cp: The start of the string
40  * @endp: A pointer to the end of the parsed string will be placed here
41  * @base: The number base to use
42  *
43  * This function is obsolete. Please use kstrtoull instead.
44  */
45 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
46 {
47 	unsigned long long result;
48 	unsigned int rv;
49 
50 	cp = _parse_integer_fixup_radix(cp, &base);
51 	rv = _parse_integer(cp, base, &result);
52 	/* FIXME */
53 	cp += (rv & ~KSTRTOX_OVERFLOW);
54 
55 	if (endp)
56 		*endp = (char *)cp;
57 
58 	return result;
59 }
60 EXPORT_SYMBOL(simple_strtoull);
61 
62 /**
63  * simple_strtoul - convert a string to an unsigned long
64  * @cp: The start of the string
65  * @endp: A pointer to the end of the parsed string will be placed here
66  * @base: The number base to use
67  *
68  * This function is obsolete. Please use kstrtoul instead.
69  */
70 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
71 {
72 	return simple_strtoull(cp, endp, base);
73 }
74 EXPORT_SYMBOL(simple_strtoul);
75 
76 /**
77  * simple_strtol - convert a string to a signed long
78  * @cp: The start of the string
79  * @endp: A pointer to the end of the parsed string will be placed here
80  * @base: The number base to use
81  *
82  * This function is obsolete. Please use kstrtol instead.
83  */
84 long simple_strtol(const char *cp, char **endp, unsigned int base)
85 {
86 	if (*cp == '-')
87 		return -simple_strtoul(cp + 1, endp, base);
88 
89 	return simple_strtoul(cp, endp, base);
90 }
91 EXPORT_SYMBOL(simple_strtol);
92 
93 /**
94  * simple_strtoll - convert a string to a signed long long
95  * @cp: The start of the string
96  * @endp: A pointer to the end of the parsed string will be placed here
97  * @base: The number base to use
98  *
99  * This function is obsolete. Please use kstrtoll instead.
100  */
101 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
102 {
103 	if (*cp == '-')
104 		return -simple_strtoull(cp + 1, endp, base);
105 
106 	return simple_strtoull(cp, endp, base);
107 }
108 EXPORT_SYMBOL(simple_strtoll);
109 
110 static noinline_for_stack
111 int skip_atoi(const char **s)
112 {
113 	int i = 0;
114 
115 	while (isdigit(**s))
116 		i = i*10 + *((*s)++) - '0';
117 
118 	return i;
119 }
120 
121 /* Decimal conversion is by far the most typical, and is used
122  * for /proc and /sys data. This directly impacts e.g. top performance
123  * with many processes running. We optimize it for speed
124  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
125  * (with permission from the author, Douglas W. Jones).
126  */
127 
128 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
129 /* Formats correctly any integer in [0, 999999999] */
130 static noinline_for_stack
131 char *put_dec_full9(char *buf, unsigned q)
132 {
133 	unsigned r;
134 
135 	/*
136 	 * Possible ways to approx. divide by 10
137 	 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
138 	 * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
139 	 * (x * 0x6667) >> 18     x <      43699
140 	 * (x * 0x3334) >> 17     x <      16389
141 	 * (x * 0x199a) >> 16     x <      16389
142 	 * (x * 0x0ccd) >> 15     x <      16389
143 	 * (x * 0x0667) >> 14     x <       2739
144 	 * (x * 0x0334) >> 13     x <       1029
145 	 * (x * 0x019a) >> 12     x <       1029
146 	 * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
147 	 * (x * 0x0067) >> 10     x <        179
148 	 * (x * 0x0034) >>  9     x <         69 same
149 	 * (x * 0x001a) >>  8     x <         69 same
150 	 * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
151 	 * (x * 0x0007) >>  6     x <         19
152 	 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
153 	 */
154 	r      = (q * (uint64_t)0x1999999a) >> 32;
155 	*buf++ = (q - 10 * r) + '0'; /* 1 */
156 	q      = (r * (uint64_t)0x1999999a) >> 32;
157 	*buf++ = (r - 10 * q) + '0'; /* 2 */
158 	r      = (q * (uint64_t)0x1999999a) >> 32;
159 	*buf++ = (q - 10 * r) + '0'; /* 3 */
160 	q      = (r * (uint64_t)0x1999999a) >> 32;
161 	*buf++ = (r - 10 * q) + '0'; /* 4 */
162 	r      = (q * (uint64_t)0x1999999a) >> 32;
163 	*buf++ = (q - 10 * r) + '0'; /* 5 */
164 	/* Now value is under 10000, can avoid 64-bit multiply */
165 	q      = (r * 0x199a) >> 16;
166 	*buf++ = (r - 10 * q)  + '0'; /* 6 */
167 	r      = (q * 0xcd) >> 11;
168 	*buf++ = (q - 10 * r)  + '0'; /* 7 */
169 	q      = (r * 0xcd) >> 11;
170 	*buf++ = (r - 10 * q) + '0'; /* 8 */
171 	*buf++ = q + '0'; /* 9 */
172 	return buf;
173 }
174 #endif
175 
176 /* Similar to above but do not pad with zeros.
177  * Code can be easily arranged to print 9 digits too, but our callers
178  * always call put_dec_full9() instead when the number has 9 decimal digits.
179  */
180 static noinline_for_stack
181 char *put_dec_trunc8(char *buf, unsigned r)
182 {
183 	unsigned q;
184 
185 	/* Copy of previous function's body with added early returns */
186 	while (r >= 10000) {
187 		q = r + '0';
188 		r  = (r * (uint64_t)0x1999999a) >> 32;
189 		*buf++ = q - 10*r;
190 	}
191 
192 	q      = (r * 0x199a) >> 16;	/* r <= 9999 */
193 	*buf++ = (r - 10 * q)  + '0';
194 	if (q == 0)
195 		return buf;
196 	r      = (q * 0xcd) >> 11;	/* q <= 999 */
197 	*buf++ = (q - 10 * r)  + '0';
198 	if (r == 0)
199 		return buf;
200 	q      = (r * 0xcd) >> 11;	/* r <= 99 */
201 	*buf++ = (r - 10 * q) + '0';
202 	if (q == 0)
203 		return buf;
204 	*buf++ = q + '0';		 /* q <= 9 */
205 	return buf;
206 }
207 
208 /* There are two algorithms to print larger numbers.
209  * One is generic: divide by 1000000000 and repeatedly print
210  * groups of (up to) 9 digits. It's conceptually simple,
211  * but requires a (unsigned long long) / 1000000000 division.
212  *
213  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
214  * manipulates them cleverly and generates groups of 4 decimal digits.
215  * It so happens that it does NOT require long long division.
216  *
217  * If long is > 32 bits, division of 64-bit values is relatively easy,
218  * and we will use the first algorithm.
219  * If long long is > 64 bits (strange architecture with VERY large long long),
220  * second algorithm can't be used, and we again use the first one.
221  *
222  * Else (if long is 32 bits and long long is 64 bits) we use second one.
223  */
224 
225 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
226 
227 /* First algorithm: generic */
228 
229 static
230 char *put_dec(char *buf, unsigned long long n)
231 {
232 	if (n >= 100*1000*1000) {
233 		while (n >= 1000*1000*1000)
234 			buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
235 		if (n >= 100*1000*1000)
236 			return put_dec_full9(buf, n);
237 	}
238 	return put_dec_trunc8(buf, n);
239 }
240 
241 #else
242 
243 /* Second algorithm: valid only for 64-bit long longs */
244 
245 /* See comment in put_dec_full9 for choice of constants */
246 static noinline_for_stack
247 void put_dec_full4(char *buf, unsigned q)
248 {
249 	unsigned r;
250 	r      = (q * 0xccd) >> 15;
251 	buf[0] = (q - 10 * r) + '0';
252 	q      = (r * 0xcd) >> 11;
253 	buf[1] = (r - 10 * q)  + '0';
254 	r      = (q * 0xcd) >> 11;
255 	buf[2] = (q - 10 * r)  + '0';
256 	buf[3] = r + '0';
257 }
258 
259 /*
260  * Call put_dec_full4 on x % 10000, return x / 10000.
261  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
262  * holds for all x < 1,128,869,999.  The largest value this
263  * helper will ever be asked to convert is 1,125,520,955.
264  * (d1 in the put_dec code, assuming n is all-ones).
265  */
266 static
267 unsigned put_dec_helper4(char *buf, unsigned x)
268 {
269         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
270 
271         put_dec_full4(buf, x - q * 10000);
272         return q;
273 }
274 
275 /* Based on code by Douglas W. Jones found at
276  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
277  * (with permission from the author).
278  * Performs no 64-bit division and hence should be fast on 32-bit machines.
279  */
280 static
281 char *put_dec(char *buf, unsigned long long n)
282 {
283 	uint32_t d3, d2, d1, q, h;
284 
285 	if (n < 100*1000*1000)
286 		return put_dec_trunc8(buf, n);
287 
288 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
289 	h   = (n >> 32);
290 	d2  = (h      ) & 0xffff;
291 	d3  = (h >> 16); /* implicit "& 0xffff" */
292 
293 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
294 	q = put_dec_helper4(buf, q);
295 
296 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
297 	q = put_dec_helper4(buf+4, q);
298 
299 	q += 4749 * d3 + 42 * d2;
300 	q = put_dec_helper4(buf+8, q);
301 
302 	q += 281 * d3;
303 	buf += 12;
304 	if (q)
305 		buf = put_dec_trunc8(buf, q);
306 	else while (buf[-1] == '0')
307 		--buf;
308 
309 	return buf;
310 }
311 
312 #endif
313 
314 /*
315  * Convert passed number to decimal string.
316  * Returns the length of string.  On buffer overflow, returns 0.
317  *
318  * If speed is not important, use snprintf(). It's easy to read the code.
319  */
320 int num_to_str(char *buf, int size, unsigned long long num)
321 {
322 	char tmp[sizeof(num) * 3];
323 	int idx, len;
324 
325 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
326 	if (num <= 9) {
327 		tmp[0] = '0' + num;
328 		len = 1;
329 	} else {
330 		len = put_dec(tmp, num) - tmp;
331 	}
332 
333 	if (len > size)
334 		return 0;
335 	for (idx = 0; idx < len; ++idx)
336 		buf[idx] = tmp[len - idx - 1];
337 	return len;
338 }
339 
340 #define ZEROPAD	1		/* pad with zero */
341 #define SIGN	2		/* unsigned/signed long */
342 #define PLUS	4		/* show plus */
343 #define SPACE	8		/* space if plus */
344 #define LEFT	16		/* left justified */
345 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
346 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
347 
348 enum format_type {
349 	FORMAT_TYPE_NONE, /* Just a string part */
350 	FORMAT_TYPE_WIDTH,
351 	FORMAT_TYPE_PRECISION,
352 	FORMAT_TYPE_CHAR,
353 	FORMAT_TYPE_STR,
354 	FORMAT_TYPE_PTR,
355 	FORMAT_TYPE_PERCENT_CHAR,
356 	FORMAT_TYPE_INVALID,
357 	FORMAT_TYPE_LONG_LONG,
358 	FORMAT_TYPE_ULONG,
359 	FORMAT_TYPE_LONG,
360 	FORMAT_TYPE_UBYTE,
361 	FORMAT_TYPE_BYTE,
362 	FORMAT_TYPE_USHORT,
363 	FORMAT_TYPE_SHORT,
364 	FORMAT_TYPE_UINT,
365 	FORMAT_TYPE_INT,
366 	FORMAT_TYPE_NRCHARS,
367 	FORMAT_TYPE_SIZE_T,
368 	FORMAT_TYPE_PTRDIFF
369 };
370 
371 struct printf_spec {
372 	u8	type;		/* format_type enum */
373 	u8	flags;		/* flags to number() */
374 	u8	base;		/* number base, 8, 10 or 16 only */
375 	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
376 	s16	field_width;	/* width of output field */
377 	s16	precision;	/* # of digits/chars */
378 };
379 
380 static noinline_for_stack
381 char *number(char *buf, char *end, unsigned long long num,
382 	     struct printf_spec spec)
383 {
384 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
385 	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
386 
387 	char tmp[66];
388 	char sign;
389 	char locase;
390 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
391 	int i;
392 	bool is_zero = num == 0LL;
393 
394 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
395 	 * produces same digits or (maybe lowercased) letters */
396 	locase = (spec.flags & SMALL);
397 	if (spec.flags & LEFT)
398 		spec.flags &= ~ZEROPAD;
399 	sign = 0;
400 	if (spec.flags & SIGN) {
401 		if ((signed long long)num < 0) {
402 			sign = '-';
403 			num = -(signed long long)num;
404 			spec.field_width--;
405 		} else if (spec.flags & PLUS) {
406 			sign = '+';
407 			spec.field_width--;
408 		} else if (spec.flags & SPACE) {
409 			sign = ' ';
410 			spec.field_width--;
411 		}
412 	}
413 	if (need_pfx) {
414 		if (spec.base == 16)
415 			spec.field_width -= 2;
416 		else if (!is_zero)
417 			spec.field_width--;
418 	}
419 
420 	/* generate full string in tmp[], in reverse order */
421 	i = 0;
422 	if (num < spec.base)
423 		tmp[i++] = digits[num] | locase;
424 	/* Generic code, for any base:
425 	else do {
426 		tmp[i++] = (digits[do_div(num,base)] | locase);
427 	} while (num != 0);
428 	*/
429 	else if (spec.base != 10) { /* 8 or 16 */
430 		int mask = spec.base - 1;
431 		int shift = 3;
432 
433 		if (spec.base == 16)
434 			shift = 4;
435 		do {
436 			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
437 			num >>= shift;
438 		} while (num);
439 	} else { /* base 10 */
440 		i = put_dec(tmp, num) - tmp;
441 	}
442 
443 	/* printing 100 using %2d gives "100", not "00" */
444 	if (i > spec.precision)
445 		spec.precision = i;
446 	/* leading space padding */
447 	spec.field_width -= spec.precision;
448 	if (!(spec.flags & (ZEROPAD+LEFT))) {
449 		while (--spec.field_width >= 0) {
450 			if (buf < end)
451 				*buf = ' ';
452 			++buf;
453 		}
454 	}
455 	/* sign */
456 	if (sign) {
457 		if (buf < end)
458 			*buf = sign;
459 		++buf;
460 	}
461 	/* "0x" / "0" prefix */
462 	if (need_pfx) {
463 		if (spec.base == 16 || !is_zero) {
464 			if (buf < end)
465 				*buf = '0';
466 			++buf;
467 		}
468 		if (spec.base == 16) {
469 			if (buf < end)
470 				*buf = ('X' | locase);
471 			++buf;
472 		}
473 	}
474 	/* zero or space padding */
475 	if (!(spec.flags & LEFT)) {
476 		char c = (spec.flags & ZEROPAD) ? '0' : ' ';
477 		while (--spec.field_width >= 0) {
478 			if (buf < end)
479 				*buf = c;
480 			++buf;
481 		}
482 	}
483 	/* hmm even more zero padding? */
484 	while (i <= --spec.precision) {
485 		if (buf < end)
486 			*buf = '0';
487 		++buf;
488 	}
489 	/* actual digits of result */
490 	while (--i >= 0) {
491 		if (buf < end)
492 			*buf = tmp[i];
493 		++buf;
494 	}
495 	/* trailing space padding */
496 	while (--spec.field_width >= 0) {
497 		if (buf < end)
498 			*buf = ' ';
499 		++buf;
500 	}
501 
502 	return buf;
503 }
504 
505 static noinline_for_stack
506 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
507 {
508 	int len, i;
509 
510 	if ((unsigned long)s < PAGE_SIZE)
511 		s = "(null)";
512 
513 	len = strnlen(s, spec.precision);
514 
515 	if (!(spec.flags & LEFT)) {
516 		while (len < spec.field_width--) {
517 			if (buf < end)
518 				*buf = ' ';
519 			++buf;
520 		}
521 	}
522 	for (i = 0; i < len; ++i) {
523 		if (buf < end)
524 			*buf = *s;
525 		++buf; ++s;
526 	}
527 	while (len < spec.field_width--) {
528 		if (buf < end)
529 			*buf = ' ';
530 		++buf;
531 	}
532 
533 	return buf;
534 }
535 
536 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
537 {
538 	size_t size;
539 	if (buf >= end)	/* nowhere to put anything */
540 		return;
541 	size = end - buf;
542 	if (size <= spaces) {
543 		memset(buf, ' ', size);
544 		return;
545 	}
546 	if (len) {
547 		if (len > size - spaces)
548 			len = size - spaces;
549 		memmove(buf + spaces, buf, len);
550 	}
551 	memset(buf, ' ', spaces);
552 }
553 
554 static noinline_for_stack
555 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
556 		  const char *fmt)
557 {
558 	const char *array[4], *s;
559 	const struct dentry *p;
560 	int depth;
561 	int i, n;
562 
563 	switch (fmt[1]) {
564 		case '2': case '3': case '4':
565 			depth = fmt[1] - '0';
566 			break;
567 		default:
568 			depth = 1;
569 	}
570 
571 	rcu_read_lock();
572 	for (i = 0; i < depth; i++, d = p) {
573 		p = ACCESS_ONCE(d->d_parent);
574 		array[i] = ACCESS_ONCE(d->d_name.name);
575 		if (p == d) {
576 			if (i)
577 				array[i] = "";
578 			i++;
579 			break;
580 		}
581 	}
582 	s = array[--i];
583 	for (n = 0; n != spec.precision; n++, buf++) {
584 		char c = *s++;
585 		if (!c) {
586 			if (!i)
587 				break;
588 			c = '/';
589 			s = array[--i];
590 		}
591 		if (buf < end)
592 			*buf = c;
593 	}
594 	rcu_read_unlock();
595 	if (n < spec.field_width) {
596 		/* we want to pad the sucker */
597 		unsigned spaces = spec.field_width - n;
598 		if (!(spec.flags & LEFT)) {
599 			widen(buf - n, end, n, spaces);
600 			return buf + spaces;
601 		}
602 		while (spaces--) {
603 			if (buf < end)
604 				*buf = ' ';
605 			++buf;
606 		}
607 	}
608 	return buf;
609 }
610 
611 static noinline_for_stack
612 char *symbol_string(char *buf, char *end, void *ptr,
613 		    struct printf_spec spec, const char *fmt)
614 {
615 	unsigned long value;
616 #ifdef CONFIG_KALLSYMS
617 	char sym[KSYM_SYMBOL_LEN];
618 #endif
619 
620 	if (fmt[1] == 'R')
621 		ptr = __builtin_extract_return_addr(ptr);
622 	value = (unsigned long)ptr;
623 
624 #ifdef CONFIG_KALLSYMS
625 	if (*fmt == 'B')
626 		sprint_backtrace(sym, value);
627 	else if (*fmt != 'f' && *fmt != 's')
628 		sprint_symbol(sym, value);
629 	else
630 		sprint_symbol_no_offset(sym, value);
631 
632 	return string(buf, end, sym, spec);
633 #else
634 	spec.field_width = 2 * sizeof(void *);
635 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
636 	spec.base = 16;
637 
638 	return number(buf, end, value, spec);
639 #endif
640 }
641 
642 static noinline_for_stack
643 char *resource_string(char *buf, char *end, struct resource *res,
644 		      struct printf_spec spec, const char *fmt)
645 {
646 #ifndef IO_RSRC_PRINTK_SIZE
647 #define IO_RSRC_PRINTK_SIZE	6
648 #endif
649 
650 #ifndef MEM_RSRC_PRINTK_SIZE
651 #define MEM_RSRC_PRINTK_SIZE	10
652 #endif
653 	static const struct printf_spec io_spec = {
654 		.base = 16,
655 		.field_width = IO_RSRC_PRINTK_SIZE,
656 		.precision = -1,
657 		.flags = SPECIAL | SMALL | ZEROPAD,
658 	};
659 	static const struct printf_spec mem_spec = {
660 		.base = 16,
661 		.field_width = MEM_RSRC_PRINTK_SIZE,
662 		.precision = -1,
663 		.flags = SPECIAL | SMALL | ZEROPAD,
664 	};
665 	static const struct printf_spec bus_spec = {
666 		.base = 16,
667 		.field_width = 2,
668 		.precision = -1,
669 		.flags = SMALL | ZEROPAD,
670 	};
671 	static const struct printf_spec dec_spec = {
672 		.base = 10,
673 		.precision = -1,
674 		.flags = 0,
675 	};
676 	static const struct printf_spec str_spec = {
677 		.field_width = -1,
678 		.precision = 10,
679 		.flags = LEFT,
680 	};
681 	static const struct printf_spec flag_spec = {
682 		.base = 16,
683 		.precision = -1,
684 		.flags = SPECIAL | SMALL,
685 	};
686 
687 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
688 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
689 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
690 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
691 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
692 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
693 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
694 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
695 
696 	char *p = sym, *pend = sym + sizeof(sym);
697 	int decode = (fmt[0] == 'R') ? 1 : 0;
698 	const struct printf_spec *specp;
699 
700 	*p++ = '[';
701 	if (res->flags & IORESOURCE_IO) {
702 		p = string(p, pend, "io  ", str_spec);
703 		specp = &io_spec;
704 	} else if (res->flags & IORESOURCE_MEM) {
705 		p = string(p, pend, "mem ", str_spec);
706 		specp = &mem_spec;
707 	} else if (res->flags & IORESOURCE_IRQ) {
708 		p = string(p, pend, "irq ", str_spec);
709 		specp = &dec_spec;
710 	} else if (res->flags & IORESOURCE_DMA) {
711 		p = string(p, pend, "dma ", str_spec);
712 		specp = &dec_spec;
713 	} else if (res->flags & IORESOURCE_BUS) {
714 		p = string(p, pend, "bus ", str_spec);
715 		specp = &bus_spec;
716 	} else {
717 		p = string(p, pend, "??? ", str_spec);
718 		specp = &mem_spec;
719 		decode = 0;
720 	}
721 	p = number(p, pend, res->start, *specp);
722 	if (res->start != res->end) {
723 		*p++ = '-';
724 		p = number(p, pend, res->end, *specp);
725 	}
726 	if (decode) {
727 		if (res->flags & IORESOURCE_MEM_64)
728 			p = string(p, pend, " 64bit", str_spec);
729 		if (res->flags & IORESOURCE_PREFETCH)
730 			p = string(p, pend, " pref", str_spec);
731 		if (res->flags & IORESOURCE_WINDOW)
732 			p = string(p, pend, " window", str_spec);
733 		if (res->flags & IORESOURCE_DISABLED)
734 			p = string(p, pend, " disabled", str_spec);
735 	} else {
736 		p = string(p, pend, " flags ", str_spec);
737 		p = number(p, pend, res->flags, flag_spec);
738 	}
739 	*p++ = ']';
740 	*p = '\0';
741 
742 	return string(buf, end, sym, spec);
743 }
744 
745 static noinline_for_stack
746 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
747 		 const char *fmt)
748 {
749 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
750 				   negative value, fallback to the default */
751 	char separator;
752 
753 	if (spec.field_width == 0)
754 		/* nothing to print */
755 		return buf;
756 
757 	if (ZERO_OR_NULL_PTR(addr))
758 		/* NULL pointer */
759 		return string(buf, end, NULL, spec);
760 
761 	switch (fmt[1]) {
762 	case 'C':
763 		separator = ':';
764 		break;
765 	case 'D':
766 		separator = '-';
767 		break;
768 	case 'N':
769 		separator = 0;
770 		break;
771 	default:
772 		separator = ' ';
773 		break;
774 	}
775 
776 	if (spec.field_width > 0)
777 		len = min_t(int, spec.field_width, 64);
778 
779 	for (i = 0; i < len && buf < end - 1; i++) {
780 		buf = hex_byte_pack(buf, addr[i]);
781 
782 		if (buf < end && separator && i != len - 1)
783 			*buf++ = separator;
784 	}
785 
786 	return buf;
787 }
788 
789 static noinline_for_stack
790 char *mac_address_string(char *buf, char *end, u8 *addr,
791 			 struct printf_spec spec, const char *fmt)
792 {
793 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
794 	char *p = mac_addr;
795 	int i;
796 	char separator;
797 	bool reversed = false;
798 
799 	switch (fmt[1]) {
800 	case 'F':
801 		separator = '-';
802 		break;
803 
804 	case 'R':
805 		reversed = true;
806 		/* fall through */
807 
808 	default:
809 		separator = ':';
810 		break;
811 	}
812 
813 	for (i = 0; i < 6; i++) {
814 		if (reversed)
815 			p = hex_byte_pack(p, addr[5 - i]);
816 		else
817 			p = hex_byte_pack(p, addr[i]);
818 
819 		if (fmt[0] == 'M' && i != 5)
820 			*p++ = separator;
821 	}
822 	*p = '\0';
823 
824 	return string(buf, end, mac_addr, spec);
825 }
826 
827 static noinline_for_stack
828 char *ip4_string(char *p, const u8 *addr, const char *fmt)
829 {
830 	int i;
831 	bool leading_zeros = (fmt[0] == 'i');
832 	int index;
833 	int step;
834 
835 	switch (fmt[2]) {
836 	case 'h':
837 #ifdef __BIG_ENDIAN
838 		index = 0;
839 		step = 1;
840 #else
841 		index = 3;
842 		step = -1;
843 #endif
844 		break;
845 	case 'l':
846 		index = 3;
847 		step = -1;
848 		break;
849 	case 'n':
850 	case 'b':
851 	default:
852 		index = 0;
853 		step = 1;
854 		break;
855 	}
856 	for (i = 0; i < 4; i++) {
857 		char temp[3];	/* hold each IP quad in reverse order */
858 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
859 		if (leading_zeros) {
860 			if (digits < 3)
861 				*p++ = '0';
862 			if (digits < 2)
863 				*p++ = '0';
864 		}
865 		/* reverse the digits in the quad */
866 		while (digits--)
867 			*p++ = temp[digits];
868 		if (i < 3)
869 			*p++ = '.';
870 		index += step;
871 	}
872 	*p = '\0';
873 
874 	return p;
875 }
876 
877 static noinline_for_stack
878 char *ip6_compressed_string(char *p, const char *addr)
879 {
880 	int i, j, range;
881 	unsigned char zerolength[8];
882 	int longest = 1;
883 	int colonpos = -1;
884 	u16 word;
885 	u8 hi, lo;
886 	bool needcolon = false;
887 	bool useIPv4;
888 	struct in6_addr in6;
889 
890 	memcpy(&in6, addr, sizeof(struct in6_addr));
891 
892 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
893 
894 	memset(zerolength, 0, sizeof(zerolength));
895 
896 	if (useIPv4)
897 		range = 6;
898 	else
899 		range = 8;
900 
901 	/* find position of longest 0 run */
902 	for (i = 0; i < range; i++) {
903 		for (j = i; j < range; j++) {
904 			if (in6.s6_addr16[j] != 0)
905 				break;
906 			zerolength[i]++;
907 		}
908 	}
909 	for (i = 0; i < range; i++) {
910 		if (zerolength[i] > longest) {
911 			longest = zerolength[i];
912 			colonpos = i;
913 		}
914 	}
915 	if (longest == 1)		/* don't compress a single 0 */
916 		colonpos = -1;
917 
918 	/* emit address */
919 	for (i = 0; i < range; i++) {
920 		if (i == colonpos) {
921 			if (needcolon || i == 0)
922 				*p++ = ':';
923 			*p++ = ':';
924 			needcolon = false;
925 			i += longest - 1;
926 			continue;
927 		}
928 		if (needcolon) {
929 			*p++ = ':';
930 			needcolon = false;
931 		}
932 		/* hex u16 without leading 0s */
933 		word = ntohs(in6.s6_addr16[i]);
934 		hi = word >> 8;
935 		lo = word & 0xff;
936 		if (hi) {
937 			if (hi > 0x0f)
938 				p = hex_byte_pack(p, hi);
939 			else
940 				*p++ = hex_asc_lo(hi);
941 			p = hex_byte_pack(p, lo);
942 		}
943 		else if (lo > 0x0f)
944 			p = hex_byte_pack(p, lo);
945 		else
946 			*p++ = hex_asc_lo(lo);
947 		needcolon = true;
948 	}
949 
950 	if (useIPv4) {
951 		if (needcolon)
952 			*p++ = ':';
953 		p = ip4_string(p, &in6.s6_addr[12], "I4");
954 	}
955 	*p = '\0';
956 
957 	return p;
958 }
959 
960 static noinline_for_stack
961 char *ip6_string(char *p, const char *addr, const char *fmt)
962 {
963 	int i;
964 
965 	for (i = 0; i < 8; i++) {
966 		p = hex_byte_pack(p, *addr++);
967 		p = hex_byte_pack(p, *addr++);
968 		if (fmt[0] == 'I' && i != 7)
969 			*p++ = ':';
970 	}
971 	*p = '\0';
972 
973 	return p;
974 }
975 
976 static noinline_for_stack
977 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
978 		      struct printf_spec spec, const char *fmt)
979 {
980 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
981 
982 	if (fmt[0] == 'I' && fmt[2] == 'c')
983 		ip6_compressed_string(ip6_addr, addr);
984 	else
985 		ip6_string(ip6_addr, addr, fmt);
986 
987 	return string(buf, end, ip6_addr, spec);
988 }
989 
990 static noinline_for_stack
991 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
992 		      struct printf_spec spec, const char *fmt)
993 {
994 	char ip4_addr[sizeof("255.255.255.255")];
995 
996 	ip4_string(ip4_addr, addr, fmt);
997 
998 	return string(buf, end, ip4_addr, spec);
999 }
1000 
1001 static noinline_for_stack
1002 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1003 			 struct printf_spec spec, const char *fmt)
1004 {
1005 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1006 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1007 		      sizeof(":12345") + sizeof("/123456789") +
1008 		      sizeof("%1234567890")];
1009 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1010 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1011 	char fmt6[2] = { fmt[0], '6' };
1012 	u8 off = 0;
1013 
1014 	fmt++;
1015 	while (isalpha(*++fmt)) {
1016 		switch (*fmt) {
1017 		case 'p':
1018 			have_p = true;
1019 			break;
1020 		case 'f':
1021 			have_f = true;
1022 			break;
1023 		case 's':
1024 			have_s = true;
1025 			break;
1026 		case 'c':
1027 			have_c = true;
1028 			break;
1029 		}
1030 	}
1031 
1032 	if (have_p || have_s || have_f) {
1033 		*p = '[';
1034 		off = 1;
1035 	}
1036 
1037 	if (fmt6[0] == 'I' && have_c)
1038 		p = ip6_compressed_string(ip6_addr + off, addr);
1039 	else
1040 		p = ip6_string(ip6_addr + off, addr, fmt6);
1041 
1042 	if (have_p || have_s || have_f)
1043 		*p++ = ']';
1044 
1045 	if (have_p) {
1046 		*p++ = ':';
1047 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1048 	}
1049 	if (have_f) {
1050 		*p++ = '/';
1051 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1052 					  IPV6_FLOWINFO_MASK), spec);
1053 	}
1054 	if (have_s) {
1055 		*p++ = '%';
1056 		p = number(p, pend, sa->sin6_scope_id, spec);
1057 	}
1058 	*p = '\0';
1059 
1060 	return string(buf, end, ip6_addr, spec);
1061 }
1062 
1063 static noinline_for_stack
1064 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1065 			 struct printf_spec spec, const char *fmt)
1066 {
1067 	bool have_p = false;
1068 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1069 	char *pend = ip4_addr + sizeof(ip4_addr);
1070 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1071 	char fmt4[3] = { fmt[0], '4', 0 };
1072 
1073 	fmt++;
1074 	while (isalpha(*++fmt)) {
1075 		switch (*fmt) {
1076 		case 'p':
1077 			have_p = true;
1078 			break;
1079 		case 'h':
1080 		case 'l':
1081 		case 'n':
1082 		case 'b':
1083 			fmt4[2] = *fmt;
1084 			break;
1085 		}
1086 	}
1087 
1088 	p = ip4_string(ip4_addr, addr, fmt4);
1089 	if (have_p) {
1090 		*p++ = ':';
1091 		p = number(p, pend, ntohs(sa->sin_port), spec);
1092 	}
1093 	*p = '\0';
1094 
1095 	return string(buf, end, ip4_addr, spec);
1096 }
1097 
1098 static noinline_for_stack
1099 char *uuid_string(char *buf, char *end, const u8 *addr,
1100 		  struct printf_spec spec, const char *fmt)
1101 {
1102 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1103 	char *p = uuid;
1104 	int i;
1105 	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1106 	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1107 	const u8 *index = be;
1108 	bool uc = false;
1109 
1110 	switch (*(++fmt)) {
1111 	case 'L':
1112 		uc = true;		/* fall-through */
1113 	case 'l':
1114 		index = le;
1115 		break;
1116 	case 'B':
1117 		uc = true;
1118 		break;
1119 	}
1120 
1121 	for (i = 0; i < 16; i++) {
1122 		p = hex_byte_pack(p, addr[index[i]]);
1123 		switch (i) {
1124 		case 3:
1125 		case 5:
1126 		case 7:
1127 		case 9:
1128 			*p++ = '-';
1129 			break;
1130 		}
1131 	}
1132 
1133 	*p = 0;
1134 
1135 	if (uc) {
1136 		p = uuid;
1137 		do {
1138 			*p = toupper(*p);
1139 		} while (*(++p));
1140 	}
1141 
1142 	return string(buf, end, uuid, spec);
1143 }
1144 
1145 static
1146 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1147 		      struct printf_spec spec)
1148 {
1149 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1150 	if (spec.field_width == -1)
1151 		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1152 	spec.base = 16;
1153 
1154 	return number(buf, end, *(const netdev_features_t *)addr, spec);
1155 }
1156 
1157 int kptr_restrict __read_mostly;
1158 
1159 /*
1160  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1161  * by an extra set of alphanumeric characters that are extended format
1162  * specifiers.
1163  *
1164  * Right now we handle:
1165  *
1166  * - 'F' For symbolic function descriptor pointers with offset
1167  * - 'f' For simple symbolic function names without offset
1168  * - 'S' For symbolic direct pointers with offset
1169  * - 's' For symbolic direct pointers without offset
1170  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1171  * - 'B' For backtraced symbolic direct pointers with offset
1172  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1173  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1174  * - 'M' For a 6-byte MAC address, it prints the address in the
1175  *       usual colon-separated hex notation
1176  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1177  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1178  *       with a dash-separated hex notation
1179  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1180  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1181  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1182  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1183  *       [S][pfs]
1184  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1185  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1186  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1187  *       IPv6 omits the colons (01020304...0f)
1188  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1189  *       [S][pfs]
1190  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1191  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1192  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1193  * - 'I[6S]c' for IPv6 addresses printed as specified by
1194  *       http://tools.ietf.org/html/rfc5952
1195  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1196  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1197  *       Options for %pU are:
1198  *         b big endian lower case hex (default)
1199  *         B big endian UPPER case hex
1200  *         l little endian lower case hex
1201  *         L little endian UPPER case hex
1202  *           big endian output byte order is:
1203  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1204  *           little endian output byte order is:
1205  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1206  * - 'V' For a struct va_format which contains a format string * and va_list *,
1207  *       call vsnprintf(->format, *->va_list).
1208  *       Implements a "recursive vsnprintf".
1209  *       Do not use this feature without some mechanism to verify the
1210  *       correctness of the format string and va_list arguments.
1211  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1212  * - 'NF' For a netdev_features_t
1213  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1214  *            a certain separator (' ' by default):
1215  *              C colon
1216  *              D dash
1217  *              N no separator
1218  *            The maximum supported length is 64 bytes of the input. Consider
1219  *            to use print_hex_dump() for the larger input.
1220  * - 'a' For a phys_addr_t type and its derivative types (passed by reference)
1221  *
1222  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1223  * function pointers are really function descriptors, which contain a
1224  * pointer to the real address.
1225  */
1226 static noinline_for_stack
1227 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1228 	      struct printf_spec spec)
1229 {
1230 	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1231 
1232 	if (!ptr && *fmt != 'K') {
1233 		/*
1234 		 * Print (null) with the same width as a pointer so it makes
1235 		 * tabular output look nice.
1236 		 */
1237 		if (spec.field_width == -1)
1238 			spec.field_width = default_width;
1239 		return string(buf, end, "(null)", spec);
1240 	}
1241 
1242 	switch (*fmt) {
1243 	case 'F':
1244 	case 'f':
1245 		ptr = dereference_function_descriptor(ptr);
1246 		/* Fallthrough */
1247 	case 'S':
1248 	case 's':
1249 	case 'B':
1250 		return symbol_string(buf, end, ptr, spec, fmt);
1251 	case 'R':
1252 	case 'r':
1253 		return resource_string(buf, end, ptr, spec, fmt);
1254 	case 'h':
1255 		return hex_string(buf, end, ptr, spec, fmt);
1256 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
1257 	case 'm':			/* Contiguous: 000102030405 */
1258 					/* [mM]F (FDDI) */
1259 					/* [mM]R (Reverse order; Bluetooth) */
1260 		return mac_address_string(buf, end, ptr, spec, fmt);
1261 	case 'I':			/* Formatted IP supported
1262 					 * 4:	1.2.3.4
1263 					 * 6:	0001:0203:...:0708
1264 					 * 6c:	1::708 or 1::1.2.3.4
1265 					 */
1266 	case 'i':			/* Contiguous:
1267 					 * 4:	001.002.003.004
1268 					 * 6:   000102...0f
1269 					 */
1270 		switch (fmt[1]) {
1271 		case '6':
1272 			return ip6_addr_string(buf, end, ptr, spec, fmt);
1273 		case '4':
1274 			return ip4_addr_string(buf, end, ptr, spec, fmt);
1275 		case 'S': {
1276 			const union {
1277 				struct sockaddr		raw;
1278 				struct sockaddr_in	v4;
1279 				struct sockaddr_in6	v6;
1280 			} *sa = ptr;
1281 
1282 			switch (sa->raw.sa_family) {
1283 			case AF_INET:
1284 				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1285 			case AF_INET6:
1286 				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1287 			default:
1288 				return string(buf, end, "(invalid address)", spec);
1289 			}}
1290 		}
1291 		break;
1292 	case 'U':
1293 		return uuid_string(buf, end, ptr, spec, fmt);
1294 	case 'V':
1295 		{
1296 			va_list va;
1297 
1298 			va_copy(va, *((struct va_format *)ptr)->va);
1299 			buf += vsnprintf(buf, end > buf ? end - buf : 0,
1300 					 ((struct va_format *)ptr)->fmt, va);
1301 			va_end(va);
1302 			return buf;
1303 		}
1304 	case 'K':
1305 		/*
1306 		 * %pK cannot be used in IRQ context because its test
1307 		 * for CAP_SYSLOG would be meaningless.
1308 		 */
1309 		if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1310 				      in_nmi())) {
1311 			if (spec.field_width == -1)
1312 				spec.field_width = default_width;
1313 			return string(buf, end, "pK-error", spec);
1314 		}
1315 		if (!((kptr_restrict == 0) ||
1316 		      (kptr_restrict == 1 &&
1317 		       has_capability_noaudit(current, CAP_SYSLOG))))
1318 			ptr = NULL;
1319 		break;
1320 	case 'N':
1321 		switch (fmt[1]) {
1322 		case 'F':
1323 			return netdev_feature_string(buf, end, ptr, spec);
1324 		}
1325 		break;
1326 	case 'a':
1327 		spec.flags |= SPECIAL | SMALL | ZEROPAD;
1328 		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1329 		spec.base = 16;
1330 		return number(buf, end,
1331 			      (unsigned long long) *((phys_addr_t *)ptr), spec);
1332 	case 'd':
1333 		return dentry_name(buf, end, ptr, spec, fmt);
1334 	case 'D':
1335 		return dentry_name(buf, end,
1336 				   ((const struct file *)ptr)->f_path.dentry,
1337 				   spec, fmt);
1338 	}
1339 	spec.flags |= SMALL;
1340 	if (spec.field_width == -1) {
1341 		spec.field_width = default_width;
1342 		spec.flags |= ZEROPAD;
1343 	}
1344 	spec.base = 16;
1345 
1346 	return number(buf, end, (unsigned long) ptr, spec);
1347 }
1348 
1349 /*
1350  * Helper function to decode printf style format.
1351  * Each call decode a token from the format and return the
1352  * number of characters read (or likely the delta where it wants
1353  * to go on the next call).
1354  * The decoded token is returned through the parameters
1355  *
1356  * 'h', 'l', or 'L' for integer fields
1357  * 'z' support added 23/7/1999 S.H.
1358  * 'z' changed to 'Z' --davidm 1/25/99
1359  * 't' added for ptrdiff_t
1360  *
1361  * @fmt: the format string
1362  * @type of the token returned
1363  * @flags: various flags such as +, -, # tokens..
1364  * @field_width: overwritten width
1365  * @base: base of the number (octal, hex, ...)
1366  * @precision: precision of a number
1367  * @qualifier: qualifier of a number (long, size_t, ...)
1368  */
1369 static noinline_for_stack
1370 int format_decode(const char *fmt, struct printf_spec *spec)
1371 {
1372 	const char *start = fmt;
1373 
1374 	/* we finished early by reading the field width */
1375 	if (spec->type == FORMAT_TYPE_WIDTH) {
1376 		if (spec->field_width < 0) {
1377 			spec->field_width = -spec->field_width;
1378 			spec->flags |= LEFT;
1379 		}
1380 		spec->type = FORMAT_TYPE_NONE;
1381 		goto precision;
1382 	}
1383 
1384 	/* we finished early by reading the precision */
1385 	if (spec->type == FORMAT_TYPE_PRECISION) {
1386 		if (spec->precision < 0)
1387 			spec->precision = 0;
1388 
1389 		spec->type = FORMAT_TYPE_NONE;
1390 		goto qualifier;
1391 	}
1392 
1393 	/* By default */
1394 	spec->type = FORMAT_TYPE_NONE;
1395 
1396 	for (; *fmt ; ++fmt) {
1397 		if (*fmt == '%')
1398 			break;
1399 	}
1400 
1401 	/* Return the current non-format string */
1402 	if (fmt != start || !*fmt)
1403 		return fmt - start;
1404 
1405 	/* Process flags */
1406 	spec->flags = 0;
1407 
1408 	while (1) { /* this also skips first '%' */
1409 		bool found = true;
1410 
1411 		++fmt;
1412 
1413 		switch (*fmt) {
1414 		case '-': spec->flags |= LEFT;    break;
1415 		case '+': spec->flags |= PLUS;    break;
1416 		case ' ': spec->flags |= SPACE;   break;
1417 		case '#': spec->flags |= SPECIAL; break;
1418 		case '0': spec->flags |= ZEROPAD; break;
1419 		default:  found = false;
1420 		}
1421 
1422 		if (!found)
1423 			break;
1424 	}
1425 
1426 	/* get field width */
1427 	spec->field_width = -1;
1428 
1429 	if (isdigit(*fmt))
1430 		spec->field_width = skip_atoi(&fmt);
1431 	else if (*fmt == '*') {
1432 		/* it's the next argument */
1433 		spec->type = FORMAT_TYPE_WIDTH;
1434 		return ++fmt - start;
1435 	}
1436 
1437 precision:
1438 	/* get the precision */
1439 	spec->precision = -1;
1440 	if (*fmt == '.') {
1441 		++fmt;
1442 		if (isdigit(*fmt)) {
1443 			spec->precision = skip_atoi(&fmt);
1444 			if (spec->precision < 0)
1445 				spec->precision = 0;
1446 		} else if (*fmt == '*') {
1447 			/* it's the next argument */
1448 			spec->type = FORMAT_TYPE_PRECISION;
1449 			return ++fmt - start;
1450 		}
1451 	}
1452 
1453 qualifier:
1454 	/* get the conversion qualifier */
1455 	spec->qualifier = -1;
1456 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1457 	    _tolower(*fmt) == 'z' || *fmt == 't') {
1458 		spec->qualifier = *fmt++;
1459 		if (unlikely(spec->qualifier == *fmt)) {
1460 			if (spec->qualifier == 'l') {
1461 				spec->qualifier = 'L';
1462 				++fmt;
1463 			} else if (spec->qualifier == 'h') {
1464 				spec->qualifier = 'H';
1465 				++fmt;
1466 			}
1467 		}
1468 	}
1469 
1470 	/* default base */
1471 	spec->base = 10;
1472 	switch (*fmt) {
1473 	case 'c':
1474 		spec->type = FORMAT_TYPE_CHAR;
1475 		return ++fmt - start;
1476 
1477 	case 's':
1478 		spec->type = FORMAT_TYPE_STR;
1479 		return ++fmt - start;
1480 
1481 	case 'p':
1482 		spec->type = FORMAT_TYPE_PTR;
1483 		return fmt - start;
1484 		/* skip alnum */
1485 
1486 	case 'n':
1487 		spec->type = FORMAT_TYPE_NRCHARS;
1488 		return ++fmt - start;
1489 
1490 	case '%':
1491 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1492 		return ++fmt - start;
1493 
1494 	/* integer number formats - set up the flags and "break" */
1495 	case 'o':
1496 		spec->base = 8;
1497 		break;
1498 
1499 	case 'x':
1500 		spec->flags |= SMALL;
1501 
1502 	case 'X':
1503 		spec->base = 16;
1504 		break;
1505 
1506 	case 'd':
1507 	case 'i':
1508 		spec->flags |= SIGN;
1509 	case 'u':
1510 		break;
1511 
1512 	default:
1513 		spec->type = FORMAT_TYPE_INVALID;
1514 		return fmt - start;
1515 	}
1516 
1517 	if (spec->qualifier == 'L')
1518 		spec->type = FORMAT_TYPE_LONG_LONG;
1519 	else if (spec->qualifier == 'l') {
1520 		if (spec->flags & SIGN)
1521 			spec->type = FORMAT_TYPE_LONG;
1522 		else
1523 			spec->type = FORMAT_TYPE_ULONG;
1524 	} else if (_tolower(spec->qualifier) == 'z') {
1525 		spec->type = FORMAT_TYPE_SIZE_T;
1526 	} else if (spec->qualifier == 't') {
1527 		spec->type = FORMAT_TYPE_PTRDIFF;
1528 	} else if (spec->qualifier == 'H') {
1529 		if (spec->flags & SIGN)
1530 			spec->type = FORMAT_TYPE_BYTE;
1531 		else
1532 			spec->type = FORMAT_TYPE_UBYTE;
1533 	} else if (spec->qualifier == 'h') {
1534 		if (spec->flags & SIGN)
1535 			spec->type = FORMAT_TYPE_SHORT;
1536 		else
1537 			spec->type = FORMAT_TYPE_USHORT;
1538 	} else {
1539 		if (spec->flags & SIGN)
1540 			spec->type = FORMAT_TYPE_INT;
1541 		else
1542 			spec->type = FORMAT_TYPE_UINT;
1543 	}
1544 
1545 	return ++fmt - start;
1546 }
1547 
1548 /**
1549  * vsnprintf - Format a string and place it in a buffer
1550  * @buf: The buffer to place the result into
1551  * @size: The size of the buffer, including the trailing null space
1552  * @fmt: The format string to use
1553  * @args: Arguments for the format string
1554  *
1555  * This function follows C99 vsnprintf, but has some extensions:
1556  * %pS output the name of a text symbol with offset
1557  * %ps output the name of a text symbol without offset
1558  * %pF output the name of a function pointer with its offset
1559  * %pf output the name of a function pointer without its offset
1560  * %pB output the name of a backtrace symbol with its offset
1561  * %pR output the address range in a struct resource with decoded flags
1562  * %pr output the address range in a struct resource with raw flags
1563  * %pM output a 6-byte MAC address with colons
1564  * %pMR output a 6-byte MAC address with colons in reversed order
1565  * %pMF output a 6-byte MAC address with dashes
1566  * %pm output a 6-byte MAC address without colons
1567  * %pmR output a 6-byte MAC address without colons in reversed order
1568  * %pI4 print an IPv4 address without leading zeros
1569  * %pi4 print an IPv4 address with leading zeros
1570  * %pI6 print an IPv6 address with colons
1571  * %pi6 print an IPv6 address without colons
1572  * %pI6c print an IPv6 address as specified by RFC 5952
1573  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1574  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1575  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1576  *   case.
1577  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1578  *           bytes of the input)
1579  * %n is ignored
1580  *
1581  * ** Please update Documentation/printk-formats.txt when making changes **
1582  *
1583  * The return value is the number of characters which would
1584  * be generated for the given input, excluding the trailing
1585  * '\0', as per ISO C99. If you want to have the exact
1586  * number of characters written into @buf as return value
1587  * (not including the trailing '\0'), use vscnprintf(). If the
1588  * return is greater than or equal to @size, the resulting
1589  * string is truncated.
1590  *
1591  * If you're not already dealing with a va_list consider using snprintf().
1592  */
1593 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1594 {
1595 	unsigned long long num;
1596 	char *str, *end;
1597 	struct printf_spec spec = {0};
1598 
1599 	/* Reject out-of-range values early.  Large positive sizes are
1600 	   used for unknown buffer sizes. */
1601 	if (WARN_ON_ONCE((int) size < 0))
1602 		return 0;
1603 
1604 	str = buf;
1605 	end = buf + size;
1606 
1607 	/* Make sure end is always >= buf */
1608 	if (end < buf) {
1609 		end = ((void *)-1);
1610 		size = end - buf;
1611 	}
1612 
1613 	while (*fmt) {
1614 		const char *old_fmt = fmt;
1615 		int read = format_decode(fmt, &spec);
1616 
1617 		fmt += read;
1618 
1619 		switch (spec.type) {
1620 		case FORMAT_TYPE_NONE: {
1621 			int copy = read;
1622 			if (str < end) {
1623 				if (copy > end - str)
1624 					copy = end - str;
1625 				memcpy(str, old_fmt, copy);
1626 			}
1627 			str += read;
1628 			break;
1629 		}
1630 
1631 		case FORMAT_TYPE_WIDTH:
1632 			spec.field_width = va_arg(args, int);
1633 			break;
1634 
1635 		case FORMAT_TYPE_PRECISION:
1636 			spec.precision = va_arg(args, int);
1637 			break;
1638 
1639 		case FORMAT_TYPE_CHAR: {
1640 			char c;
1641 
1642 			if (!(spec.flags & LEFT)) {
1643 				while (--spec.field_width > 0) {
1644 					if (str < end)
1645 						*str = ' ';
1646 					++str;
1647 
1648 				}
1649 			}
1650 			c = (unsigned char) va_arg(args, int);
1651 			if (str < end)
1652 				*str = c;
1653 			++str;
1654 			while (--spec.field_width > 0) {
1655 				if (str < end)
1656 					*str = ' ';
1657 				++str;
1658 			}
1659 			break;
1660 		}
1661 
1662 		case FORMAT_TYPE_STR:
1663 			str = string(str, end, va_arg(args, char *), spec);
1664 			break;
1665 
1666 		case FORMAT_TYPE_PTR:
1667 			str = pointer(fmt+1, str, end, va_arg(args, void *),
1668 				      spec);
1669 			while (isalnum(*fmt))
1670 				fmt++;
1671 			break;
1672 
1673 		case FORMAT_TYPE_PERCENT_CHAR:
1674 			if (str < end)
1675 				*str = '%';
1676 			++str;
1677 			break;
1678 
1679 		case FORMAT_TYPE_INVALID:
1680 			if (str < end)
1681 				*str = '%';
1682 			++str;
1683 			break;
1684 
1685 		case FORMAT_TYPE_NRCHARS: {
1686 			u8 qualifier = spec.qualifier;
1687 
1688 			if (qualifier == 'l') {
1689 				long *ip = va_arg(args, long *);
1690 				*ip = (str - buf);
1691 			} else if (_tolower(qualifier) == 'z') {
1692 				size_t *ip = va_arg(args, size_t *);
1693 				*ip = (str - buf);
1694 			} else {
1695 				int *ip = va_arg(args, int *);
1696 				*ip = (str - buf);
1697 			}
1698 			break;
1699 		}
1700 
1701 		default:
1702 			switch (spec.type) {
1703 			case FORMAT_TYPE_LONG_LONG:
1704 				num = va_arg(args, long long);
1705 				break;
1706 			case FORMAT_TYPE_ULONG:
1707 				num = va_arg(args, unsigned long);
1708 				break;
1709 			case FORMAT_TYPE_LONG:
1710 				num = va_arg(args, long);
1711 				break;
1712 			case FORMAT_TYPE_SIZE_T:
1713 				if (spec.flags & SIGN)
1714 					num = va_arg(args, ssize_t);
1715 				else
1716 					num = va_arg(args, size_t);
1717 				break;
1718 			case FORMAT_TYPE_PTRDIFF:
1719 				num = va_arg(args, ptrdiff_t);
1720 				break;
1721 			case FORMAT_TYPE_UBYTE:
1722 				num = (unsigned char) va_arg(args, int);
1723 				break;
1724 			case FORMAT_TYPE_BYTE:
1725 				num = (signed char) va_arg(args, int);
1726 				break;
1727 			case FORMAT_TYPE_USHORT:
1728 				num = (unsigned short) va_arg(args, int);
1729 				break;
1730 			case FORMAT_TYPE_SHORT:
1731 				num = (short) va_arg(args, int);
1732 				break;
1733 			case FORMAT_TYPE_INT:
1734 				num = (int) va_arg(args, int);
1735 				break;
1736 			default:
1737 				num = va_arg(args, unsigned int);
1738 			}
1739 
1740 			str = number(str, end, num, spec);
1741 		}
1742 	}
1743 
1744 	if (size > 0) {
1745 		if (str < end)
1746 			*str = '\0';
1747 		else
1748 			end[-1] = '\0';
1749 	}
1750 
1751 	/* the trailing null byte doesn't count towards the total */
1752 	return str-buf;
1753 
1754 }
1755 EXPORT_SYMBOL(vsnprintf);
1756 
1757 /**
1758  * vscnprintf - Format a string and place it in a buffer
1759  * @buf: The buffer to place the result into
1760  * @size: The size of the buffer, including the trailing null space
1761  * @fmt: The format string to use
1762  * @args: Arguments for the format string
1763  *
1764  * The return value is the number of characters which have been written into
1765  * the @buf not including the trailing '\0'. If @size is == 0 the function
1766  * returns 0.
1767  *
1768  * If you're not already dealing with a va_list consider using scnprintf().
1769  *
1770  * See the vsnprintf() documentation for format string extensions over C99.
1771  */
1772 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1773 {
1774 	int i;
1775 
1776 	i = vsnprintf(buf, size, fmt, args);
1777 
1778 	if (likely(i < size))
1779 		return i;
1780 	if (size != 0)
1781 		return size - 1;
1782 	return 0;
1783 }
1784 EXPORT_SYMBOL(vscnprintf);
1785 
1786 /**
1787  * snprintf - Format a string and place it in a buffer
1788  * @buf: The buffer to place the result into
1789  * @size: The size of the buffer, including the trailing null space
1790  * @fmt: The format string to use
1791  * @...: Arguments for the format string
1792  *
1793  * The return value is the number of characters which would be
1794  * generated for the given input, excluding the trailing null,
1795  * as per ISO C99.  If the return is greater than or equal to
1796  * @size, the resulting string is truncated.
1797  *
1798  * See the vsnprintf() documentation for format string extensions over C99.
1799  */
1800 int snprintf(char *buf, size_t size, const char *fmt, ...)
1801 {
1802 	va_list args;
1803 	int i;
1804 
1805 	va_start(args, fmt);
1806 	i = vsnprintf(buf, size, fmt, args);
1807 	va_end(args);
1808 
1809 	return i;
1810 }
1811 EXPORT_SYMBOL(snprintf);
1812 
1813 /**
1814  * scnprintf - Format a string and place it in a buffer
1815  * @buf: The buffer to place the result into
1816  * @size: The size of the buffer, including the trailing null space
1817  * @fmt: The format string to use
1818  * @...: Arguments for the format string
1819  *
1820  * The return value is the number of characters written into @buf not including
1821  * the trailing '\0'. If @size is == 0 the function returns 0.
1822  */
1823 
1824 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1825 {
1826 	va_list args;
1827 	int i;
1828 
1829 	va_start(args, fmt);
1830 	i = vscnprintf(buf, size, fmt, args);
1831 	va_end(args);
1832 
1833 	return i;
1834 }
1835 EXPORT_SYMBOL(scnprintf);
1836 
1837 /**
1838  * vsprintf - Format a string and place it in a buffer
1839  * @buf: The buffer to place the result into
1840  * @fmt: The format string to use
1841  * @args: Arguments for the format string
1842  *
1843  * The function returns the number of characters written
1844  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1845  * buffer overflows.
1846  *
1847  * If you're not already dealing with a va_list consider using sprintf().
1848  *
1849  * See the vsnprintf() documentation for format string extensions over C99.
1850  */
1851 int vsprintf(char *buf, const char *fmt, va_list args)
1852 {
1853 	return vsnprintf(buf, INT_MAX, fmt, args);
1854 }
1855 EXPORT_SYMBOL(vsprintf);
1856 
1857 /**
1858  * sprintf - Format a string and place it in a buffer
1859  * @buf: The buffer to place the result into
1860  * @fmt: The format string to use
1861  * @...: Arguments for the format string
1862  *
1863  * The function returns the number of characters written
1864  * into @buf. Use snprintf() or scnprintf() in order to avoid
1865  * buffer overflows.
1866  *
1867  * See the vsnprintf() documentation for format string extensions over C99.
1868  */
1869 int sprintf(char *buf, const char *fmt, ...)
1870 {
1871 	va_list args;
1872 	int i;
1873 
1874 	va_start(args, fmt);
1875 	i = vsnprintf(buf, INT_MAX, fmt, args);
1876 	va_end(args);
1877 
1878 	return i;
1879 }
1880 EXPORT_SYMBOL(sprintf);
1881 
1882 #ifdef CONFIG_BINARY_PRINTF
1883 /*
1884  * bprintf service:
1885  * vbin_printf() - VA arguments to binary data
1886  * bstr_printf() - Binary data to text string
1887  */
1888 
1889 /**
1890  * vbin_printf - Parse a format string and place args' binary value in a buffer
1891  * @bin_buf: The buffer to place args' binary value
1892  * @size: The size of the buffer(by words(32bits), not characters)
1893  * @fmt: The format string to use
1894  * @args: Arguments for the format string
1895  *
1896  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1897  * is skiped.
1898  *
1899  * The return value is the number of words(32bits) which would be generated for
1900  * the given input.
1901  *
1902  * NOTE:
1903  * If the return value is greater than @size, the resulting bin_buf is NOT
1904  * valid for bstr_printf().
1905  */
1906 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1907 {
1908 	struct printf_spec spec = {0};
1909 	char *str, *end;
1910 
1911 	str = (char *)bin_buf;
1912 	end = (char *)(bin_buf + size);
1913 
1914 #define save_arg(type)							\
1915 do {									\
1916 	if (sizeof(type) == 8) {					\
1917 		unsigned long long value;				\
1918 		str = PTR_ALIGN(str, sizeof(u32));			\
1919 		value = va_arg(args, unsigned long long);		\
1920 		if (str + sizeof(type) <= end) {			\
1921 			*(u32 *)str = *(u32 *)&value;			\
1922 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
1923 		}							\
1924 	} else {							\
1925 		unsigned long value;					\
1926 		str = PTR_ALIGN(str, sizeof(type));			\
1927 		value = va_arg(args, int);				\
1928 		if (str + sizeof(type) <= end)				\
1929 			*(typeof(type) *)str = (type)value;		\
1930 	}								\
1931 	str += sizeof(type);						\
1932 } while (0)
1933 
1934 	while (*fmt) {
1935 		int read = format_decode(fmt, &spec);
1936 
1937 		fmt += read;
1938 
1939 		switch (spec.type) {
1940 		case FORMAT_TYPE_NONE:
1941 		case FORMAT_TYPE_INVALID:
1942 		case FORMAT_TYPE_PERCENT_CHAR:
1943 			break;
1944 
1945 		case FORMAT_TYPE_WIDTH:
1946 		case FORMAT_TYPE_PRECISION:
1947 			save_arg(int);
1948 			break;
1949 
1950 		case FORMAT_TYPE_CHAR:
1951 			save_arg(char);
1952 			break;
1953 
1954 		case FORMAT_TYPE_STR: {
1955 			const char *save_str = va_arg(args, char *);
1956 			size_t len;
1957 
1958 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1959 					|| (unsigned long)save_str < PAGE_SIZE)
1960 				save_str = "(null)";
1961 			len = strlen(save_str) + 1;
1962 			if (str + len < end)
1963 				memcpy(str, save_str, len);
1964 			str += len;
1965 			break;
1966 		}
1967 
1968 		case FORMAT_TYPE_PTR:
1969 			save_arg(void *);
1970 			/* skip all alphanumeric pointer suffixes */
1971 			while (isalnum(*fmt))
1972 				fmt++;
1973 			break;
1974 
1975 		case FORMAT_TYPE_NRCHARS: {
1976 			/* skip %n 's argument */
1977 			u8 qualifier = spec.qualifier;
1978 			void *skip_arg;
1979 			if (qualifier == 'l')
1980 				skip_arg = va_arg(args, long *);
1981 			else if (_tolower(qualifier) == 'z')
1982 				skip_arg = va_arg(args, size_t *);
1983 			else
1984 				skip_arg = va_arg(args, int *);
1985 			break;
1986 		}
1987 
1988 		default:
1989 			switch (spec.type) {
1990 
1991 			case FORMAT_TYPE_LONG_LONG:
1992 				save_arg(long long);
1993 				break;
1994 			case FORMAT_TYPE_ULONG:
1995 			case FORMAT_TYPE_LONG:
1996 				save_arg(unsigned long);
1997 				break;
1998 			case FORMAT_TYPE_SIZE_T:
1999 				save_arg(size_t);
2000 				break;
2001 			case FORMAT_TYPE_PTRDIFF:
2002 				save_arg(ptrdiff_t);
2003 				break;
2004 			case FORMAT_TYPE_UBYTE:
2005 			case FORMAT_TYPE_BYTE:
2006 				save_arg(char);
2007 				break;
2008 			case FORMAT_TYPE_USHORT:
2009 			case FORMAT_TYPE_SHORT:
2010 				save_arg(short);
2011 				break;
2012 			default:
2013 				save_arg(int);
2014 			}
2015 		}
2016 	}
2017 
2018 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2019 #undef save_arg
2020 }
2021 EXPORT_SYMBOL_GPL(vbin_printf);
2022 
2023 /**
2024  * bstr_printf - Format a string from binary arguments and place it in a buffer
2025  * @buf: The buffer to place the result into
2026  * @size: The size of the buffer, including the trailing null space
2027  * @fmt: The format string to use
2028  * @bin_buf: Binary arguments for the format string
2029  *
2030  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2031  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2032  * a binary buffer that generated by vbin_printf.
2033  *
2034  * The format follows C99 vsnprintf, but has some extensions:
2035  *  see vsnprintf comment for details.
2036  *
2037  * The return value is the number of characters which would
2038  * be generated for the given input, excluding the trailing
2039  * '\0', as per ISO C99. If you want to have the exact
2040  * number of characters written into @buf as return value
2041  * (not including the trailing '\0'), use vscnprintf(). If the
2042  * return is greater than or equal to @size, the resulting
2043  * string is truncated.
2044  */
2045 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2046 {
2047 	struct printf_spec spec = {0};
2048 	char *str, *end;
2049 	const char *args = (const char *)bin_buf;
2050 
2051 	if (WARN_ON_ONCE((int) size < 0))
2052 		return 0;
2053 
2054 	str = buf;
2055 	end = buf + size;
2056 
2057 #define get_arg(type)							\
2058 ({									\
2059 	typeof(type) value;						\
2060 	if (sizeof(type) == 8) {					\
2061 		args = PTR_ALIGN(args, sizeof(u32));			\
2062 		*(u32 *)&value = *(u32 *)args;				\
2063 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2064 	} else {							\
2065 		args = PTR_ALIGN(args, sizeof(type));			\
2066 		value = *(typeof(type) *)args;				\
2067 	}								\
2068 	args += sizeof(type);						\
2069 	value;								\
2070 })
2071 
2072 	/* Make sure end is always >= buf */
2073 	if (end < buf) {
2074 		end = ((void *)-1);
2075 		size = end - buf;
2076 	}
2077 
2078 	while (*fmt) {
2079 		const char *old_fmt = fmt;
2080 		int read = format_decode(fmt, &spec);
2081 
2082 		fmt += read;
2083 
2084 		switch (spec.type) {
2085 		case FORMAT_TYPE_NONE: {
2086 			int copy = read;
2087 			if (str < end) {
2088 				if (copy > end - str)
2089 					copy = end - str;
2090 				memcpy(str, old_fmt, copy);
2091 			}
2092 			str += read;
2093 			break;
2094 		}
2095 
2096 		case FORMAT_TYPE_WIDTH:
2097 			spec.field_width = get_arg(int);
2098 			break;
2099 
2100 		case FORMAT_TYPE_PRECISION:
2101 			spec.precision = get_arg(int);
2102 			break;
2103 
2104 		case FORMAT_TYPE_CHAR: {
2105 			char c;
2106 
2107 			if (!(spec.flags & LEFT)) {
2108 				while (--spec.field_width > 0) {
2109 					if (str < end)
2110 						*str = ' ';
2111 					++str;
2112 				}
2113 			}
2114 			c = (unsigned char) get_arg(char);
2115 			if (str < end)
2116 				*str = c;
2117 			++str;
2118 			while (--spec.field_width > 0) {
2119 				if (str < end)
2120 					*str = ' ';
2121 				++str;
2122 			}
2123 			break;
2124 		}
2125 
2126 		case FORMAT_TYPE_STR: {
2127 			const char *str_arg = args;
2128 			args += strlen(str_arg) + 1;
2129 			str = string(str, end, (char *)str_arg, spec);
2130 			break;
2131 		}
2132 
2133 		case FORMAT_TYPE_PTR:
2134 			str = pointer(fmt+1, str, end, get_arg(void *), spec);
2135 			while (isalnum(*fmt))
2136 				fmt++;
2137 			break;
2138 
2139 		case FORMAT_TYPE_PERCENT_CHAR:
2140 		case FORMAT_TYPE_INVALID:
2141 			if (str < end)
2142 				*str = '%';
2143 			++str;
2144 			break;
2145 
2146 		case FORMAT_TYPE_NRCHARS:
2147 			/* skip */
2148 			break;
2149 
2150 		default: {
2151 			unsigned long long num;
2152 
2153 			switch (spec.type) {
2154 
2155 			case FORMAT_TYPE_LONG_LONG:
2156 				num = get_arg(long long);
2157 				break;
2158 			case FORMAT_TYPE_ULONG:
2159 			case FORMAT_TYPE_LONG:
2160 				num = get_arg(unsigned long);
2161 				break;
2162 			case FORMAT_TYPE_SIZE_T:
2163 				num = get_arg(size_t);
2164 				break;
2165 			case FORMAT_TYPE_PTRDIFF:
2166 				num = get_arg(ptrdiff_t);
2167 				break;
2168 			case FORMAT_TYPE_UBYTE:
2169 				num = get_arg(unsigned char);
2170 				break;
2171 			case FORMAT_TYPE_BYTE:
2172 				num = get_arg(signed char);
2173 				break;
2174 			case FORMAT_TYPE_USHORT:
2175 				num = get_arg(unsigned short);
2176 				break;
2177 			case FORMAT_TYPE_SHORT:
2178 				num = get_arg(short);
2179 				break;
2180 			case FORMAT_TYPE_UINT:
2181 				num = get_arg(unsigned int);
2182 				break;
2183 			default:
2184 				num = get_arg(int);
2185 			}
2186 
2187 			str = number(str, end, num, spec);
2188 		} /* default: */
2189 		} /* switch(spec.type) */
2190 	} /* while(*fmt) */
2191 
2192 	if (size > 0) {
2193 		if (str < end)
2194 			*str = '\0';
2195 		else
2196 			end[-1] = '\0';
2197 	}
2198 
2199 #undef get_arg
2200 
2201 	/* the trailing null byte doesn't count towards the total */
2202 	return str - buf;
2203 }
2204 EXPORT_SYMBOL_GPL(bstr_printf);
2205 
2206 /**
2207  * bprintf - Parse a format string and place args' binary value in a buffer
2208  * @bin_buf: The buffer to place args' binary value
2209  * @size: The size of the buffer(by words(32bits), not characters)
2210  * @fmt: The format string to use
2211  * @...: Arguments for the format string
2212  *
2213  * The function returns the number of words(u32) written
2214  * into @bin_buf.
2215  */
2216 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2217 {
2218 	va_list args;
2219 	int ret;
2220 
2221 	va_start(args, fmt);
2222 	ret = vbin_printf(bin_buf, size, fmt, args);
2223 	va_end(args);
2224 
2225 	return ret;
2226 }
2227 EXPORT_SYMBOL_GPL(bprintf);
2228 
2229 #endif /* CONFIG_BINARY_PRINTF */
2230 
2231 /**
2232  * vsscanf - Unformat a buffer into a list of arguments
2233  * @buf:	input buffer
2234  * @fmt:	format of buffer
2235  * @args:	arguments
2236  */
2237 int vsscanf(const char *buf, const char *fmt, va_list args)
2238 {
2239 	const char *str = buf;
2240 	char *next;
2241 	char digit;
2242 	int num = 0;
2243 	u8 qualifier;
2244 	unsigned int base;
2245 	union {
2246 		long long s;
2247 		unsigned long long u;
2248 	} val;
2249 	s16 field_width;
2250 	bool is_sign;
2251 
2252 	while (*fmt) {
2253 		/* skip any white space in format */
2254 		/* white space in format matchs any amount of
2255 		 * white space, including none, in the input.
2256 		 */
2257 		if (isspace(*fmt)) {
2258 			fmt = skip_spaces(++fmt);
2259 			str = skip_spaces(str);
2260 		}
2261 
2262 		/* anything that is not a conversion must match exactly */
2263 		if (*fmt != '%' && *fmt) {
2264 			if (*fmt++ != *str++)
2265 				break;
2266 			continue;
2267 		}
2268 
2269 		if (!*fmt)
2270 			break;
2271 		++fmt;
2272 
2273 		/* skip this conversion.
2274 		 * advance both strings to next white space
2275 		 */
2276 		if (*fmt == '*') {
2277 			if (!*str)
2278 				break;
2279 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
2280 				fmt++;
2281 			while (!isspace(*str) && *str)
2282 				str++;
2283 			continue;
2284 		}
2285 
2286 		/* get field width */
2287 		field_width = -1;
2288 		if (isdigit(*fmt)) {
2289 			field_width = skip_atoi(&fmt);
2290 			if (field_width <= 0)
2291 				break;
2292 		}
2293 
2294 		/* get conversion qualifier */
2295 		qualifier = -1;
2296 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2297 		    _tolower(*fmt) == 'z') {
2298 			qualifier = *fmt++;
2299 			if (unlikely(qualifier == *fmt)) {
2300 				if (qualifier == 'h') {
2301 					qualifier = 'H';
2302 					fmt++;
2303 				} else if (qualifier == 'l') {
2304 					qualifier = 'L';
2305 					fmt++;
2306 				}
2307 			}
2308 		}
2309 
2310 		if (!*fmt)
2311 			break;
2312 
2313 		if (*fmt == 'n') {
2314 			/* return number of characters read so far */
2315 			*va_arg(args, int *) = str - buf;
2316 			++fmt;
2317 			continue;
2318 		}
2319 
2320 		if (!*str)
2321 			break;
2322 
2323 		base = 10;
2324 		is_sign = 0;
2325 
2326 		switch (*fmt++) {
2327 		case 'c':
2328 		{
2329 			char *s = (char *)va_arg(args, char*);
2330 			if (field_width == -1)
2331 				field_width = 1;
2332 			do {
2333 				*s++ = *str++;
2334 			} while (--field_width > 0 && *str);
2335 			num++;
2336 		}
2337 		continue;
2338 		case 's':
2339 		{
2340 			char *s = (char *)va_arg(args, char *);
2341 			if (field_width == -1)
2342 				field_width = SHRT_MAX;
2343 			/* first, skip leading white space in buffer */
2344 			str = skip_spaces(str);
2345 
2346 			/* now copy until next white space */
2347 			while (*str && !isspace(*str) && field_width--)
2348 				*s++ = *str++;
2349 			*s = '\0';
2350 			num++;
2351 		}
2352 		continue;
2353 		case 'o':
2354 			base = 8;
2355 			break;
2356 		case 'x':
2357 		case 'X':
2358 			base = 16;
2359 			break;
2360 		case 'i':
2361 			base = 0;
2362 		case 'd':
2363 			is_sign = 1;
2364 		case 'u':
2365 			break;
2366 		case '%':
2367 			/* looking for '%' in str */
2368 			if (*str++ != '%')
2369 				return num;
2370 			continue;
2371 		default:
2372 			/* invalid format; stop here */
2373 			return num;
2374 		}
2375 
2376 		/* have some sort of integer conversion.
2377 		 * first, skip white space in buffer.
2378 		 */
2379 		str = skip_spaces(str);
2380 
2381 		digit = *str;
2382 		if (is_sign && digit == '-')
2383 			digit = *(str + 1);
2384 
2385 		if (!digit
2386 		    || (base == 16 && !isxdigit(digit))
2387 		    || (base == 10 && !isdigit(digit))
2388 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
2389 		    || (base == 0 && !isdigit(digit)))
2390 			break;
2391 
2392 		if (is_sign)
2393 			val.s = qualifier != 'L' ?
2394 				simple_strtol(str, &next, base) :
2395 				simple_strtoll(str, &next, base);
2396 		else
2397 			val.u = qualifier != 'L' ?
2398 				simple_strtoul(str, &next, base) :
2399 				simple_strtoull(str, &next, base);
2400 
2401 		if (field_width > 0 && next - str > field_width) {
2402 			if (base == 0)
2403 				_parse_integer_fixup_radix(str, &base);
2404 			while (next - str > field_width) {
2405 				if (is_sign)
2406 					val.s = div_s64(val.s, base);
2407 				else
2408 					val.u = div_u64(val.u, base);
2409 				--next;
2410 			}
2411 		}
2412 
2413 		switch (qualifier) {
2414 		case 'H':	/* that's 'hh' in format */
2415 			if (is_sign)
2416 				*va_arg(args, signed char *) = val.s;
2417 			else
2418 				*va_arg(args, unsigned char *) = val.u;
2419 			break;
2420 		case 'h':
2421 			if (is_sign)
2422 				*va_arg(args, short *) = val.s;
2423 			else
2424 				*va_arg(args, unsigned short *) = val.u;
2425 			break;
2426 		case 'l':
2427 			if (is_sign)
2428 				*va_arg(args, long *) = val.s;
2429 			else
2430 				*va_arg(args, unsigned long *) = val.u;
2431 			break;
2432 		case 'L':
2433 			if (is_sign)
2434 				*va_arg(args, long long *) = val.s;
2435 			else
2436 				*va_arg(args, unsigned long long *) = val.u;
2437 			break;
2438 		case 'Z':
2439 		case 'z':
2440 			*va_arg(args, size_t *) = val.u;
2441 			break;
2442 		default:
2443 			if (is_sign)
2444 				*va_arg(args, int *) = val.s;
2445 			else
2446 				*va_arg(args, unsigned int *) = val.u;
2447 			break;
2448 		}
2449 		num++;
2450 
2451 		if (!next)
2452 			break;
2453 		str = next;
2454 	}
2455 
2456 	return num;
2457 }
2458 EXPORT_SYMBOL(vsscanf);
2459 
2460 /**
2461  * sscanf - Unformat a buffer into a list of arguments
2462  * @buf:	input buffer
2463  * @fmt:	formatting of buffer
2464  * @...:	resulting arguments
2465  */
2466 int sscanf(const char *buf, const char *fmt, ...)
2467 {
2468 	va_list args;
2469 	int i;
2470 
2471 	va_start(args, fmt);
2472 	i = vsscanf(buf, fmt, args);
2473 	va_end(args);
2474 
2475 	return i;
2476 }
2477 EXPORT_SYMBOL(sscanf);
2478