xref: /openbmc/linux/lib/vsprintf.c (revision 483eb062)
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 <linux/cred.h>
31 #include <net/addrconf.h>
32 
33 #include <asm/page.h>		/* for PAGE_SIZE */
34 #include <asm/sections.h>	/* for dereference_function_descriptor() */
35 
36 #include "kstrtox.h"
37 
38 /**
39  * simple_strtoull - convert a string to an unsigned long long
40  * @cp: The start of the string
41  * @endp: A pointer to the end of the parsed string will be placed here
42  * @base: The number base to use
43  *
44  * This function is obsolete. Please use kstrtoull instead.
45  */
46 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
47 {
48 	unsigned long long result;
49 	unsigned int rv;
50 
51 	cp = _parse_integer_fixup_radix(cp, &base);
52 	rv = _parse_integer(cp, base, &result);
53 	/* FIXME */
54 	cp += (rv & ~KSTRTOX_OVERFLOW);
55 
56 	if (endp)
57 		*endp = (char *)cp;
58 
59 	return result;
60 }
61 EXPORT_SYMBOL(simple_strtoull);
62 
63 /**
64  * simple_strtoul - convert a string to an unsigned long
65  * @cp: The start of the string
66  * @endp: A pointer to the end of the parsed string will be placed here
67  * @base: The number base to use
68  *
69  * This function is obsolete. Please use kstrtoul instead.
70  */
71 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
72 {
73 	return simple_strtoull(cp, endp, base);
74 }
75 EXPORT_SYMBOL(simple_strtoul);
76 
77 /**
78  * simple_strtol - convert a string to a signed long
79  * @cp: The start of the string
80  * @endp: A pointer to the end of the parsed string will be placed here
81  * @base: The number base to use
82  *
83  * This function is obsolete. Please use kstrtol instead.
84  */
85 long simple_strtol(const char *cp, char **endp, unsigned int base)
86 {
87 	if (*cp == '-')
88 		return -simple_strtoul(cp + 1, endp, base);
89 
90 	return simple_strtoul(cp, endp, base);
91 }
92 EXPORT_SYMBOL(simple_strtol);
93 
94 /**
95  * simple_strtoll - convert a string to a signed long long
96  * @cp: The start of the string
97  * @endp: A pointer to the end of the parsed string will be placed here
98  * @base: The number base to use
99  *
100  * This function is obsolete. Please use kstrtoll instead.
101  */
102 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
103 {
104 	if (*cp == '-')
105 		return -simple_strtoull(cp + 1, endp, base);
106 
107 	return simple_strtoull(cp, endp, base);
108 }
109 EXPORT_SYMBOL(simple_strtoll);
110 
111 static noinline_for_stack
112 int skip_atoi(const char **s)
113 {
114 	int i = 0;
115 
116 	while (isdigit(**s))
117 		i = i*10 + *((*s)++) - '0';
118 
119 	return i;
120 }
121 
122 /* Decimal conversion is by far the most typical, and is used
123  * for /proc and /sys data. This directly impacts e.g. top performance
124  * with many processes running. We optimize it for speed
125  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
126  * (with permission from the author, Douglas W. Jones).
127  */
128 
129 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
130 /* Formats correctly any integer in [0, 999999999] */
131 static noinline_for_stack
132 char *put_dec_full9(char *buf, unsigned q)
133 {
134 	unsigned r;
135 
136 	/*
137 	 * Possible ways to approx. divide by 10
138 	 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
139 	 * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
140 	 * (x * 0x6667) >> 18     x <      43699
141 	 * (x * 0x3334) >> 17     x <      16389
142 	 * (x * 0x199a) >> 16     x <      16389
143 	 * (x * 0x0ccd) >> 15     x <      16389
144 	 * (x * 0x0667) >> 14     x <       2739
145 	 * (x * 0x0334) >> 13     x <       1029
146 	 * (x * 0x019a) >> 12     x <       1029
147 	 * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
148 	 * (x * 0x0067) >> 10     x <        179
149 	 * (x * 0x0034) >>  9     x <         69 same
150 	 * (x * 0x001a) >>  8     x <         69 same
151 	 * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
152 	 * (x * 0x0007) >>  6     x <         19
153 	 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
154 	 */
155 	r      = (q * (uint64_t)0x1999999a) >> 32;
156 	*buf++ = (q - 10 * r) + '0'; /* 1 */
157 	q      = (r * (uint64_t)0x1999999a) >> 32;
158 	*buf++ = (r - 10 * q) + '0'; /* 2 */
159 	r      = (q * (uint64_t)0x1999999a) >> 32;
160 	*buf++ = (q - 10 * r) + '0'; /* 3 */
161 	q      = (r * (uint64_t)0x1999999a) >> 32;
162 	*buf++ = (r - 10 * q) + '0'; /* 4 */
163 	r      = (q * (uint64_t)0x1999999a) >> 32;
164 	*buf++ = (q - 10 * r) + '0'; /* 5 */
165 	/* Now value is under 10000, can avoid 64-bit multiply */
166 	q      = (r * 0x199a) >> 16;
167 	*buf++ = (r - 10 * q)  + '0'; /* 6 */
168 	r      = (q * 0xcd) >> 11;
169 	*buf++ = (q - 10 * r)  + '0'; /* 7 */
170 	q      = (r * 0xcd) >> 11;
171 	*buf++ = (r - 10 * q) + '0'; /* 8 */
172 	*buf++ = q + '0'; /* 9 */
173 	return buf;
174 }
175 #endif
176 
177 /* Similar to above but do not pad with zeros.
178  * Code can be easily arranged to print 9 digits too, but our callers
179  * always call put_dec_full9() instead when the number has 9 decimal digits.
180  */
181 static noinline_for_stack
182 char *put_dec_trunc8(char *buf, unsigned r)
183 {
184 	unsigned q;
185 
186 	/* Copy of previous function's body with added early returns */
187 	while (r >= 10000) {
188 		q = r + '0';
189 		r  = (r * (uint64_t)0x1999999a) >> 32;
190 		*buf++ = q - 10*r;
191 	}
192 
193 	q      = (r * 0x199a) >> 16;	/* r <= 9999 */
194 	*buf++ = (r - 10 * q)  + '0';
195 	if (q == 0)
196 		return buf;
197 	r      = (q * 0xcd) >> 11;	/* q <= 999 */
198 	*buf++ = (q - 10 * r)  + '0';
199 	if (r == 0)
200 		return buf;
201 	q      = (r * 0xcd) >> 11;	/* r <= 99 */
202 	*buf++ = (r - 10 * q) + '0';
203 	if (q == 0)
204 		return buf;
205 	*buf++ = q + '0';		 /* q <= 9 */
206 	return buf;
207 }
208 
209 /* There are two algorithms to print larger numbers.
210  * One is generic: divide by 1000000000 and repeatedly print
211  * groups of (up to) 9 digits. It's conceptually simple,
212  * but requires a (unsigned long long) / 1000000000 division.
213  *
214  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
215  * manipulates them cleverly and generates groups of 4 decimal digits.
216  * It so happens that it does NOT require long long division.
217  *
218  * If long is > 32 bits, division of 64-bit values is relatively easy,
219  * and we will use the first algorithm.
220  * If long long is > 64 bits (strange architecture with VERY large long long),
221  * second algorithm can't be used, and we again use the first one.
222  *
223  * Else (if long is 32 bits and long long is 64 bits) we use second one.
224  */
225 
226 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
227 
228 /* First algorithm: generic */
229 
230 static
231 char *put_dec(char *buf, unsigned long long n)
232 {
233 	if (n >= 100*1000*1000) {
234 		while (n >= 1000*1000*1000)
235 			buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
236 		if (n >= 100*1000*1000)
237 			return put_dec_full9(buf, n);
238 	}
239 	return put_dec_trunc8(buf, n);
240 }
241 
242 #else
243 
244 /* Second algorithm: valid only for 64-bit long longs */
245 
246 /* See comment in put_dec_full9 for choice of constants */
247 static noinline_for_stack
248 void put_dec_full4(char *buf, unsigned q)
249 {
250 	unsigned r;
251 	r      = (q * 0xccd) >> 15;
252 	buf[0] = (q - 10 * r) + '0';
253 	q      = (r * 0xcd) >> 11;
254 	buf[1] = (r - 10 * q)  + '0';
255 	r      = (q * 0xcd) >> 11;
256 	buf[2] = (q - 10 * r)  + '0';
257 	buf[3] = r + '0';
258 }
259 
260 /*
261  * Call put_dec_full4 on x % 10000, return x / 10000.
262  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
263  * holds for all x < 1,128,869,999.  The largest value this
264  * helper will ever be asked to convert is 1,125,520,955.
265  * (d1 in the put_dec code, assuming n is all-ones).
266  */
267 static
268 unsigned put_dec_helper4(char *buf, unsigned x)
269 {
270         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
271 
272         put_dec_full4(buf, x - q * 10000);
273         return q;
274 }
275 
276 /* Based on code by Douglas W. Jones found at
277  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
278  * (with permission from the author).
279  * Performs no 64-bit division and hence should be fast on 32-bit machines.
280  */
281 static
282 char *put_dec(char *buf, unsigned long long n)
283 {
284 	uint32_t d3, d2, d1, q, h;
285 
286 	if (n < 100*1000*1000)
287 		return put_dec_trunc8(buf, n);
288 
289 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
290 	h   = (n >> 32);
291 	d2  = (h      ) & 0xffff;
292 	d3  = (h >> 16); /* implicit "& 0xffff" */
293 
294 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
295 	q = put_dec_helper4(buf, q);
296 
297 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
298 	q = put_dec_helper4(buf+4, q);
299 
300 	q += 4749 * d3 + 42 * d2;
301 	q = put_dec_helper4(buf+8, q);
302 
303 	q += 281 * d3;
304 	buf += 12;
305 	if (q)
306 		buf = put_dec_trunc8(buf, q);
307 	else while (buf[-1] == '0')
308 		--buf;
309 
310 	return buf;
311 }
312 
313 #endif
314 
315 /*
316  * Convert passed number to decimal string.
317  * Returns the length of string.  On buffer overflow, returns 0.
318  *
319  * If speed is not important, use snprintf(). It's easy to read the code.
320  */
321 int num_to_str(char *buf, int size, unsigned long long num)
322 {
323 	char tmp[sizeof(num) * 3];
324 	int idx, len;
325 
326 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
327 	if (num <= 9) {
328 		tmp[0] = '0' + num;
329 		len = 1;
330 	} else {
331 		len = put_dec(tmp, num) - tmp;
332 	}
333 
334 	if (len > size)
335 		return 0;
336 	for (idx = 0; idx < len; ++idx)
337 		buf[idx] = tmp[len - idx - 1];
338 	return len;
339 }
340 
341 #define ZEROPAD	1		/* pad with zero */
342 #define SIGN	2		/* unsigned/signed long */
343 #define PLUS	4		/* show plus */
344 #define SPACE	8		/* space if plus */
345 #define LEFT	16		/* left justified */
346 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
347 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
348 
349 enum format_type {
350 	FORMAT_TYPE_NONE, /* Just a string part */
351 	FORMAT_TYPE_WIDTH,
352 	FORMAT_TYPE_PRECISION,
353 	FORMAT_TYPE_CHAR,
354 	FORMAT_TYPE_STR,
355 	FORMAT_TYPE_PTR,
356 	FORMAT_TYPE_PERCENT_CHAR,
357 	FORMAT_TYPE_INVALID,
358 	FORMAT_TYPE_LONG_LONG,
359 	FORMAT_TYPE_ULONG,
360 	FORMAT_TYPE_LONG,
361 	FORMAT_TYPE_UBYTE,
362 	FORMAT_TYPE_BYTE,
363 	FORMAT_TYPE_USHORT,
364 	FORMAT_TYPE_SHORT,
365 	FORMAT_TYPE_UINT,
366 	FORMAT_TYPE_INT,
367 	FORMAT_TYPE_NRCHARS,
368 	FORMAT_TYPE_SIZE_T,
369 	FORMAT_TYPE_PTRDIFF
370 };
371 
372 struct printf_spec {
373 	u8	type;		/* format_type enum */
374 	u8	flags;		/* flags to number() */
375 	u8	base;		/* number base, 8, 10 or 16 only */
376 	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
377 	s16	field_width;	/* width of output field */
378 	s16	precision;	/* # of digits/chars */
379 };
380 
381 static noinline_for_stack
382 char *number(char *buf, char *end, unsigned long long num,
383 	     struct printf_spec spec)
384 {
385 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
386 	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
387 
388 	char tmp[66];
389 	char sign;
390 	char locase;
391 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
392 	int i;
393 	bool is_zero = num == 0LL;
394 
395 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
396 	 * produces same digits or (maybe lowercased) letters */
397 	locase = (spec.flags & SMALL);
398 	if (spec.flags & LEFT)
399 		spec.flags &= ~ZEROPAD;
400 	sign = 0;
401 	if (spec.flags & SIGN) {
402 		if ((signed long long)num < 0) {
403 			sign = '-';
404 			num = -(signed long long)num;
405 			spec.field_width--;
406 		} else if (spec.flags & PLUS) {
407 			sign = '+';
408 			spec.field_width--;
409 		} else if (spec.flags & SPACE) {
410 			sign = ' ';
411 			spec.field_width--;
412 		}
413 	}
414 	if (need_pfx) {
415 		if (spec.base == 16)
416 			spec.field_width -= 2;
417 		else if (!is_zero)
418 			spec.field_width--;
419 	}
420 
421 	/* generate full string in tmp[], in reverse order */
422 	i = 0;
423 	if (num < spec.base)
424 		tmp[i++] = digits[num] | locase;
425 	/* Generic code, for any base:
426 	else do {
427 		tmp[i++] = (digits[do_div(num,base)] | locase);
428 	} while (num != 0);
429 	*/
430 	else if (spec.base != 10) { /* 8 or 16 */
431 		int mask = spec.base - 1;
432 		int shift = 3;
433 
434 		if (spec.base == 16)
435 			shift = 4;
436 		do {
437 			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
438 			num >>= shift;
439 		} while (num);
440 	} else { /* base 10 */
441 		i = put_dec(tmp, num) - tmp;
442 	}
443 
444 	/* printing 100 using %2d gives "100", not "00" */
445 	if (i > spec.precision)
446 		spec.precision = i;
447 	/* leading space padding */
448 	spec.field_width -= spec.precision;
449 	if (!(spec.flags & (ZEROPAD+LEFT))) {
450 		while (--spec.field_width >= 0) {
451 			if (buf < end)
452 				*buf = ' ';
453 			++buf;
454 		}
455 	}
456 	/* sign */
457 	if (sign) {
458 		if (buf < end)
459 			*buf = sign;
460 		++buf;
461 	}
462 	/* "0x" / "0" prefix */
463 	if (need_pfx) {
464 		if (spec.base == 16 || !is_zero) {
465 			if (buf < end)
466 				*buf = '0';
467 			++buf;
468 		}
469 		if (spec.base == 16) {
470 			if (buf < end)
471 				*buf = ('X' | locase);
472 			++buf;
473 		}
474 	}
475 	/* zero or space padding */
476 	if (!(spec.flags & LEFT)) {
477 		char c = (spec.flags & ZEROPAD) ? '0' : ' ';
478 		while (--spec.field_width >= 0) {
479 			if (buf < end)
480 				*buf = c;
481 			++buf;
482 		}
483 	}
484 	/* hmm even more zero padding? */
485 	while (i <= --spec.precision) {
486 		if (buf < end)
487 			*buf = '0';
488 		++buf;
489 	}
490 	/* actual digits of result */
491 	while (--i >= 0) {
492 		if (buf < end)
493 			*buf = tmp[i];
494 		++buf;
495 	}
496 	/* trailing space padding */
497 	while (--spec.field_width >= 0) {
498 		if (buf < end)
499 			*buf = ' ';
500 		++buf;
501 	}
502 
503 	return buf;
504 }
505 
506 static noinline_for_stack
507 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
508 {
509 	int len, i;
510 
511 	if ((unsigned long)s < PAGE_SIZE)
512 		s = "(null)";
513 
514 	len = strnlen(s, spec.precision);
515 
516 	if (!(spec.flags & LEFT)) {
517 		while (len < spec.field_width--) {
518 			if (buf < end)
519 				*buf = ' ';
520 			++buf;
521 		}
522 	}
523 	for (i = 0; i < len; ++i) {
524 		if (buf < end)
525 			*buf = *s;
526 		++buf; ++s;
527 	}
528 	while (len < spec.field_width--) {
529 		if (buf < end)
530 			*buf = ' ';
531 		++buf;
532 	}
533 
534 	return buf;
535 }
536 
537 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
538 {
539 	size_t size;
540 	if (buf >= end)	/* nowhere to put anything */
541 		return;
542 	size = end - buf;
543 	if (size <= spaces) {
544 		memset(buf, ' ', size);
545 		return;
546 	}
547 	if (len) {
548 		if (len > size - spaces)
549 			len = size - spaces;
550 		memmove(buf + spaces, buf, len);
551 	}
552 	memset(buf, ' ', spaces);
553 }
554 
555 static noinline_for_stack
556 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
557 		  const char *fmt)
558 {
559 	const char *array[4], *s;
560 	const struct dentry *p;
561 	int depth;
562 	int i, n;
563 
564 	switch (fmt[1]) {
565 		case '2': case '3': case '4':
566 			depth = fmt[1] - '0';
567 			break;
568 		default:
569 			depth = 1;
570 	}
571 
572 	rcu_read_lock();
573 	for (i = 0; i < depth; i++, d = p) {
574 		p = ACCESS_ONCE(d->d_parent);
575 		array[i] = ACCESS_ONCE(d->d_name.name);
576 		if (p == d) {
577 			if (i)
578 				array[i] = "";
579 			i++;
580 			break;
581 		}
582 	}
583 	s = array[--i];
584 	for (n = 0; n != spec.precision; n++, buf++) {
585 		char c = *s++;
586 		if (!c) {
587 			if (!i)
588 				break;
589 			c = '/';
590 			s = array[--i];
591 		}
592 		if (buf < end)
593 			*buf = c;
594 	}
595 	rcu_read_unlock();
596 	if (n < spec.field_width) {
597 		/* we want to pad the sucker */
598 		unsigned spaces = spec.field_width - n;
599 		if (!(spec.flags & LEFT)) {
600 			widen(buf - n, end, n, spaces);
601 			return buf + spaces;
602 		}
603 		while (spaces--) {
604 			if (buf < end)
605 				*buf = ' ';
606 			++buf;
607 		}
608 	}
609 	return buf;
610 }
611 
612 static noinline_for_stack
613 char *symbol_string(char *buf, char *end, void *ptr,
614 		    struct printf_spec spec, const char *fmt)
615 {
616 	unsigned long value;
617 #ifdef CONFIG_KALLSYMS
618 	char sym[KSYM_SYMBOL_LEN];
619 #endif
620 
621 	if (fmt[1] == 'R')
622 		ptr = __builtin_extract_return_addr(ptr);
623 	value = (unsigned long)ptr;
624 
625 #ifdef CONFIG_KALLSYMS
626 	if (*fmt == 'B')
627 		sprint_backtrace(sym, value);
628 	else if (*fmt != 'f' && *fmt != 's')
629 		sprint_symbol(sym, value);
630 	else
631 		sprint_symbol_no_offset(sym, value);
632 
633 	return string(buf, end, sym, spec);
634 #else
635 	spec.field_width = 2 * sizeof(void *);
636 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
637 	spec.base = 16;
638 
639 	return number(buf, end, value, spec);
640 #endif
641 }
642 
643 static noinline_for_stack
644 char *resource_string(char *buf, char *end, struct resource *res,
645 		      struct printf_spec spec, const char *fmt)
646 {
647 #ifndef IO_RSRC_PRINTK_SIZE
648 #define IO_RSRC_PRINTK_SIZE	6
649 #endif
650 
651 #ifndef MEM_RSRC_PRINTK_SIZE
652 #define MEM_RSRC_PRINTK_SIZE	10
653 #endif
654 	static const struct printf_spec io_spec = {
655 		.base = 16,
656 		.field_width = IO_RSRC_PRINTK_SIZE,
657 		.precision = -1,
658 		.flags = SPECIAL | SMALL | ZEROPAD,
659 	};
660 	static const struct printf_spec mem_spec = {
661 		.base = 16,
662 		.field_width = MEM_RSRC_PRINTK_SIZE,
663 		.precision = -1,
664 		.flags = SPECIAL | SMALL | ZEROPAD,
665 	};
666 	static const struct printf_spec bus_spec = {
667 		.base = 16,
668 		.field_width = 2,
669 		.precision = -1,
670 		.flags = SMALL | ZEROPAD,
671 	};
672 	static const struct printf_spec dec_spec = {
673 		.base = 10,
674 		.precision = -1,
675 		.flags = 0,
676 	};
677 	static const struct printf_spec str_spec = {
678 		.field_width = -1,
679 		.precision = 10,
680 		.flags = LEFT,
681 	};
682 	static const struct printf_spec flag_spec = {
683 		.base = 16,
684 		.precision = -1,
685 		.flags = SPECIAL | SMALL,
686 	};
687 
688 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
689 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
690 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
691 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
692 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
693 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
694 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
695 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
696 
697 	char *p = sym, *pend = sym + sizeof(sym);
698 	int decode = (fmt[0] == 'R') ? 1 : 0;
699 	const struct printf_spec *specp;
700 
701 	*p++ = '[';
702 	if (res->flags & IORESOURCE_IO) {
703 		p = string(p, pend, "io  ", str_spec);
704 		specp = &io_spec;
705 	} else if (res->flags & IORESOURCE_MEM) {
706 		p = string(p, pend, "mem ", str_spec);
707 		specp = &mem_spec;
708 	} else if (res->flags & IORESOURCE_IRQ) {
709 		p = string(p, pend, "irq ", str_spec);
710 		specp = &dec_spec;
711 	} else if (res->flags & IORESOURCE_DMA) {
712 		p = string(p, pend, "dma ", str_spec);
713 		specp = &dec_spec;
714 	} else if (res->flags & IORESOURCE_BUS) {
715 		p = string(p, pend, "bus ", str_spec);
716 		specp = &bus_spec;
717 	} else {
718 		p = string(p, pend, "??? ", str_spec);
719 		specp = &mem_spec;
720 		decode = 0;
721 	}
722 	p = number(p, pend, res->start, *specp);
723 	if (res->start != res->end) {
724 		*p++ = '-';
725 		p = number(p, pend, res->end, *specp);
726 	}
727 	if (decode) {
728 		if (res->flags & IORESOURCE_MEM_64)
729 			p = string(p, pend, " 64bit", str_spec);
730 		if (res->flags & IORESOURCE_PREFETCH)
731 			p = string(p, pend, " pref", str_spec);
732 		if (res->flags & IORESOURCE_WINDOW)
733 			p = string(p, pend, " window", str_spec);
734 		if (res->flags & IORESOURCE_DISABLED)
735 			p = string(p, pend, " disabled", str_spec);
736 	} else {
737 		p = string(p, pend, " flags ", str_spec);
738 		p = number(p, pend, res->flags, flag_spec);
739 	}
740 	*p++ = ']';
741 	*p = '\0';
742 
743 	return string(buf, end, sym, spec);
744 }
745 
746 static noinline_for_stack
747 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
748 		 const char *fmt)
749 {
750 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
751 				   negative value, fallback to the default */
752 	char separator;
753 
754 	if (spec.field_width == 0)
755 		/* nothing to print */
756 		return buf;
757 
758 	if (ZERO_OR_NULL_PTR(addr))
759 		/* NULL pointer */
760 		return string(buf, end, NULL, spec);
761 
762 	switch (fmt[1]) {
763 	case 'C':
764 		separator = ':';
765 		break;
766 	case 'D':
767 		separator = '-';
768 		break;
769 	case 'N':
770 		separator = 0;
771 		break;
772 	default:
773 		separator = ' ';
774 		break;
775 	}
776 
777 	if (spec.field_width > 0)
778 		len = min_t(int, spec.field_width, 64);
779 
780 	for (i = 0; i < len && buf < end - 1; i++) {
781 		buf = hex_byte_pack(buf, addr[i]);
782 
783 		if (buf < end && separator && i != len - 1)
784 			*buf++ = separator;
785 	}
786 
787 	return buf;
788 }
789 
790 static noinline_for_stack
791 char *mac_address_string(char *buf, char *end, u8 *addr,
792 			 struct printf_spec spec, const char *fmt)
793 {
794 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
795 	char *p = mac_addr;
796 	int i;
797 	char separator;
798 	bool reversed = false;
799 
800 	switch (fmt[1]) {
801 	case 'F':
802 		separator = '-';
803 		break;
804 
805 	case 'R':
806 		reversed = true;
807 		/* fall through */
808 
809 	default:
810 		separator = ':';
811 		break;
812 	}
813 
814 	for (i = 0; i < 6; i++) {
815 		if (reversed)
816 			p = hex_byte_pack(p, addr[5 - i]);
817 		else
818 			p = hex_byte_pack(p, addr[i]);
819 
820 		if (fmt[0] == 'M' && i != 5)
821 			*p++ = separator;
822 	}
823 	*p = '\0';
824 
825 	return string(buf, end, mac_addr, spec);
826 }
827 
828 static noinline_for_stack
829 char *ip4_string(char *p, const u8 *addr, const char *fmt)
830 {
831 	int i;
832 	bool leading_zeros = (fmt[0] == 'i');
833 	int index;
834 	int step;
835 
836 	switch (fmt[2]) {
837 	case 'h':
838 #ifdef __BIG_ENDIAN
839 		index = 0;
840 		step = 1;
841 #else
842 		index = 3;
843 		step = -1;
844 #endif
845 		break;
846 	case 'l':
847 		index = 3;
848 		step = -1;
849 		break;
850 	case 'n':
851 	case 'b':
852 	default:
853 		index = 0;
854 		step = 1;
855 		break;
856 	}
857 	for (i = 0; i < 4; i++) {
858 		char temp[3];	/* hold each IP quad in reverse order */
859 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
860 		if (leading_zeros) {
861 			if (digits < 3)
862 				*p++ = '0';
863 			if (digits < 2)
864 				*p++ = '0';
865 		}
866 		/* reverse the digits in the quad */
867 		while (digits--)
868 			*p++ = temp[digits];
869 		if (i < 3)
870 			*p++ = '.';
871 		index += step;
872 	}
873 	*p = '\0';
874 
875 	return p;
876 }
877 
878 static noinline_for_stack
879 char *ip6_compressed_string(char *p, const char *addr)
880 {
881 	int i, j, range;
882 	unsigned char zerolength[8];
883 	int longest = 1;
884 	int colonpos = -1;
885 	u16 word;
886 	u8 hi, lo;
887 	bool needcolon = false;
888 	bool useIPv4;
889 	struct in6_addr in6;
890 
891 	memcpy(&in6, addr, sizeof(struct in6_addr));
892 
893 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
894 
895 	memset(zerolength, 0, sizeof(zerolength));
896 
897 	if (useIPv4)
898 		range = 6;
899 	else
900 		range = 8;
901 
902 	/* find position of longest 0 run */
903 	for (i = 0; i < range; i++) {
904 		for (j = i; j < range; j++) {
905 			if (in6.s6_addr16[j] != 0)
906 				break;
907 			zerolength[i]++;
908 		}
909 	}
910 	for (i = 0; i < range; i++) {
911 		if (zerolength[i] > longest) {
912 			longest = zerolength[i];
913 			colonpos = i;
914 		}
915 	}
916 	if (longest == 1)		/* don't compress a single 0 */
917 		colonpos = -1;
918 
919 	/* emit address */
920 	for (i = 0; i < range; i++) {
921 		if (i == colonpos) {
922 			if (needcolon || i == 0)
923 				*p++ = ':';
924 			*p++ = ':';
925 			needcolon = false;
926 			i += longest - 1;
927 			continue;
928 		}
929 		if (needcolon) {
930 			*p++ = ':';
931 			needcolon = false;
932 		}
933 		/* hex u16 without leading 0s */
934 		word = ntohs(in6.s6_addr16[i]);
935 		hi = word >> 8;
936 		lo = word & 0xff;
937 		if (hi) {
938 			if (hi > 0x0f)
939 				p = hex_byte_pack(p, hi);
940 			else
941 				*p++ = hex_asc_lo(hi);
942 			p = hex_byte_pack(p, lo);
943 		}
944 		else if (lo > 0x0f)
945 			p = hex_byte_pack(p, lo);
946 		else
947 			*p++ = hex_asc_lo(lo);
948 		needcolon = true;
949 	}
950 
951 	if (useIPv4) {
952 		if (needcolon)
953 			*p++ = ':';
954 		p = ip4_string(p, &in6.s6_addr[12], "I4");
955 	}
956 	*p = '\0';
957 
958 	return p;
959 }
960 
961 static noinline_for_stack
962 char *ip6_string(char *p, const char *addr, const char *fmt)
963 {
964 	int i;
965 
966 	for (i = 0; i < 8; i++) {
967 		p = hex_byte_pack(p, *addr++);
968 		p = hex_byte_pack(p, *addr++);
969 		if (fmt[0] == 'I' && i != 7)
970 			*p++ = ':';
971 	}
972 	*p = '\0';
973 
974 	return p;
975 }
976 
977 static noinline_for_stack
978 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
979 		      struct printf_spec spec, const char *fmt)
980 {
981 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
982 
983 	if (fmt[0] == 'I' && fmt[2] == 'c')
984 		ip6_compressed_string(ip6_addr, addr);
985 	else
986 		ip6_string(ip6_addr, addr, fmt);
987 
988 	return string(buf, end, ip6_addr, spec);
989 }
990 
991 static noinline_for_stack
992 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
993 		      struct printf_spec spec, const char *fmt)
994 {
995 	char ip4_addr[sizeof("255.255.255.255")];
996 
997 	ip4_string(ip4_addr, addr, fmt);
998 
999 	return string(buf, end, ip4_addr, spec);
1000 }
1001 
1002 static noinline_for_stack
1003 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1004 			 struct printf_spec spec, const char *fmt)
1005 {
1006 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1007 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1008 		      sizeof(":12345") + sizeof("/123456789") +
1009 		      sizeof("%1234567890")];
1010 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1011 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1012 	char fmt6[2] = { fmt[0], '6' };
1013 	u8 off = 0;
1014 
1015 	fmt++;
1016 	while (isalpha(*++fmt)) {
1017 		switch (*fmt) {
1018 		case 'p':
1019 			have_p = true;
1020 			break;
1021 		case 'f':
1022 			have_f = true;
1023 			break;
1024 		case 's':
1025 			have_s = true;
1026 			break;
1027 		case 'c':
1028 			have_c = true;
1029 			break;
1030 		}
1031 	}
1032 
1033 	if (have_p || have_s || have_f) {
1034 		*p = '[';
1035 		off = 1;
1036 	}
1037 
1038 	if (fmt6[0] == 'I' && have_c)
1039 		p = ip6_compressed_string(ip6_addr + off, addr);
1040 	else
1041 		p = ip6_string(ip6_addr + off, addr, fmt6);
1042 
1043 	if (have_p || have_s || have_f)
1044 		*p++ = ']';
1045 
1046 	if (have_p) {
1047 		*p++ = ':';
1048 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1049 	}
1050 	if (have_f) {
1051 		*p++ = '/';
1052 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1053 					  IPV6_FLOWINFO_MASK), spec);
1054 	}
1055 	if (have_s) {
1056 		*p++ = '%';
1057 		p = number(p, pend, sa->sin6_scope_id, spec);
1058 	}
1059 	*p = '\0';
1060 
1061 	return string(buf, end, ip6_addr, spec);
1062 }
1063 
1064 static noinline_for_stack
1065 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1066 			 struct printf_spec spec, const char *fmt)
1067 {
1068 	bool have_p = false;
1069 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1070 	char *pend = ip4_addr + sizeof(ip4_addr);
1071 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1072 	char fmt4[3] = { fmt[0], '4', 0 };
1073 
1074 	fmt++;
1075 	while (isalpha(*++fmt)) {
1076 		switch (*fmt) {
1077 		case 'p':
1078 			have_p = true;
1079 			break;
1080 		case 'h':
1081 		case 'l':
1082 		case 'n':
1083 		case 'b':
1084 			fmt4[2] = *fmt;
1085 			break;
1086 		}
1087 	}
1088 
1089 	p = ip4_string(ip4_addr, addr, fmt4);
1090 	if (have_p) {
1091 		*p++ = ':';
1092 		p = number(p, pend, ntohs(sa->sin_port), spec);
1093 	}
1094 	*p = '\0';
1095 
1096 	return string(buf, end, ip4_addr, spec);
1097 }
1098 
1099 static noinline_for_stack
1100 char *uuid_string(char *buf, char *end, const u8 *addr,
1101 		  struct printf_spec spec, const char *fmt)
1102 {
1103 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1104 	char *p = uuid;
1105 	int i;
1106 	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1107 	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1108 	const u8 *index = be;
1109 	bool uc = false;
1110 
1111 	switch (*(++fmt)) {
1112 	case 'L':
1113 		uc = true;		/* fall-through */
1114 	case 'l':
1115 		index = le;
1116 		break;
1117 	case 'B':
1118 		uc = true;
1119 		break;
1120 	}
1121 
1122 	for (i = 0; i < 16; i++) {
1123 		p = hex_byte_pack(p, addr[index[i]]);
1124 		switch (i) {
1125 		case 3:
1126 		case 5:
1127 		case 7:
1128 		case 9:
1129 			*p++ = '-';
1130 			break;
1131 		}
1132 	}
1133 
1134 	*p = 0;
1135 
1136 	if (uc) {
1137 		p = uuid;
1138 		do {
1139 			*p = toupper(*p);
1140 		} while (*(++p));
1141 	}
1142 
1143 	return string(buf, end, uuid, spec);
1144 }
1145 
1146 static
1147 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1148 		      struct printf_spec spec)
1149 {
1150 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1151 	if (spec.field_width == -1)
1152 		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1153 	spec.base = 16;
1154 
1155 	return number(buf, end, *(const netdev_features_t *)addr, spec);
1156 }
1157 
1158 static noinline_for_stack
1159 char *address_val(char *buf, char *end, const void *addr,
1160 		  struct printf_spec spec, const char *fmt)
1161 {
1162 	unsigned long long num;
1163 
1164 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1165 	spec.base = 16;
1166 
1167 	switch (fmt[1]) {
1168 	case 'd':
1169 		num = *(const dma_addr_t *)addr;
1170 		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1171 		break;
1172 	case 'p':
1173 	default:
1174 		num = *(const phys_addr_t *)addr;
1175 		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1176 		break;
1177 	}
1178 
1179 	return number(buf, end, num, spec);
1180 }
1181 
1182 int kptr_restrict __read_mostly;
1183 
1184 /*
1185  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1186  * by an extra set of alphanumeric characters that are extended format
1187  * specifiers.
1188  *
1189  * Right now we handle:
1190  *
1191  * - 'F' For symbolic function descriptor pointers with offset
1192  * - 'f' For simple symbolic function names without offset
1193  * - 'S' For symbolic direct pointers with offset
1194  * - 's' For symbolic direct pointers without offset
1195  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1196  * - 'B' For backtraced symbolic direct pointers with offset
1197  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1198  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1199  * - 'M' For a 6-byte MAC address, it prints the address in the
1200  *       usual colon-separated hex notation
1201  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1202  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1203  *       with a dash-separated hex notation
1204  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1205  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1206  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1207  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1208  *       [S][pfs]
1209  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1210  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1211  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1212  *       IPv6 omits the colons (01020304...0f)
1213  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1214  *       [S][pfs]
1215  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1216  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1217  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1218  * - 'I[6S]c' for IPv6 addresses printed as specified by
1219  *       http://tools.ietf.org/html/rfc5952
1220  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1221  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1222  *       Options for %pU are:
1223  *         b big endian lower case hex (default)
1224  *         B big endian UPPER case hex
1225  *         l little endian lower case hex
1226  *         L little endian UPPER case hex
1227  *           big endian output byte order is:
1228  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1229  *           little endian output byte order is:
1230  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1231  * - 'V' For a struct va_format which contains a format string * and va_list *,
1232  *       call vsnprintf(->format, *->va_list).
1233  *       Implements a "recursive vsnprintf".
1234  *       Do not use this feature without some mechanism to verify the
1235  *       correctness of the format string and va_list arguments.
1236  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1237  * - 'NF' For a netdev_features_t
1238  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1239  *            a certain separator (' ' by default):
1240  *              C colon
1241  *              D dash
1242  *              N no separator
1243  *            The maximum supported length is 64 bytes of the input. Consider
1244  *            to use print_hex_dump() for the larger input.
1245  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1246  *           (default assumed to be phys_addr_t, passed by reference)
1247  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1248  * - 'D[234]' Same as 'd' but for a struct file
1249  *
1250  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1251  * function pointers are really function descriptors, which contain a
1252  * pointer to the real address.
1253  */
1254 static noinline_for_stack
1255 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1256 	      struct printf_spec spec)
1257 {
1258 	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1259 
1260 	if (!ptr && *fmt != 'K') {
1261 		/*
1262 		 * Print (null) with the same width as a pointer so it makes
1263 		 * tabular output look nice.
1264 		 */
1265 		if (spec.field_width == -1)
1266 			spec.field_width = default_width;
1267 		return string(buf, end, "(null)", spec);
1268 	}
1269 
1270 	switch (*fmt) {
1271 	case 'F':
1272 	case 'f':
1273 		ptr = dereference_function_descriptor(ptr);
1274 		/* Fallthrough */
1275 	case 'S':
1276 	case 's':
1277 	case 'B':
1278 		return symbol_string(buf, end, ptr, spec, fmt);
1279 	case 'R':
1280 	case 'r':
1281 		return resource_string(buf, end, ptr, spec, fmt);
1282 	case 'h':
1283 		return hex_string(buf, end, ptr, spec, fmt);
1284 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
1285 	case 'm':			/* Contiguous: 000102030405 */
1286 					/* [mM]F (FDDI) */
1287 					/* [mM]R (Reverse order; Bluetooth) */
1288 		return mac_address_string(buf, end, ptr, spec, fmt);
1289 	case 'I':			/* Formatted IP supported
1290 					 * 4:	1.2.3.4
1291 					 * 6:	0001:0203:...:0708
1292 					 * 6c:	1::708 or 1::1.2.3.4
1293 					 */
1294 	case 'i':			/* Contiguous:
1295 					 * 4:	001.002.003.004
1296 					 * 6:   000102...0f
1297 					 */
1298 		switch (fmt[1]) {
1299 		case '6':
1300 			return ip6_addr_string(buf, end, ptr, spec, fmt);
1301 		case '4':
1302 			return ip4_addr_string(buf, end, ptr, spec, fmt);
1303 		case 'S': {
1304 			const union {
1305 				struct sockaddr		raw;
1306 				struct sockaddr_in	v4;
1307 				struct sockaddr_in6	v6;
1308 			} *sa = ptr;
1309 
1310 			switch (sa->raw.sa_family) {
1311 			case AF_INET:
1312 				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1313 			case AF_INET6:
1314 				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1315 			default:
1316 				return string(buf, end, "(invalid address)", spec);
1317 			}}
1318 		}
1319 		break;
1320 	case 'U':
1321 		return uuid_string(buf, end, ptr, spec, fmt);
1322 	case 'V':
1323 		{
1324 			va_list va;
1325 
1326 			va_copy(va, *((struct va_format *)ptr)->va);
1327 			buf += vsnprintf(buf, end > buf ? end - buf : 0,
1328 					 ((struct va_format *)ptr)->fmt, va);
1329 			va_end(va);
1330 			return buf;
1331 		}
1332 	case 'K':
1333 		/*
1334 		 * %pK cannot be used in IRQ context because its test
1335 		 * for CAP_SYSLOG would be meaningless.
1336 		 */
1337 		if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1338 				      in_nmi())) {
1339 			if (spec.field_width == -1)
1340 				spec.field_width = default_width;
1341 			return string(buf, end, "pK-error", spec);
1342 		}
1343 
1344 		switch (kptr_restrict) {
1345 		case 0:
1346 			/* Always print %pK values */
1347 			break;
1348 		case 1: {
1349 			/*
1350 			 * Only print the real pointer value if the current
1351 			 * process has CAP_SYSLOG and is running with the
1352 			 * same credentials it started with. This is because
1353 			 * access to files is checked at open() time, but %pK
1354 			 * checks permission at read() time. We don't want to
1355 			 * leak pointer values if a binary opens a file using
1356 			 * %pK and then elevates privileges before reading it.
1357 			 */
1358 			const struct cred *cred = current_cred();
1359 
1360 			if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1361 			    !uid_eq(cred->euid, cred->uid) ||
1362 			    !gid_eq(cred->egid, cred->gid))
1363 				ptr = NULL;
1364 			break;
1365 		}
1366 		case 2:
1367 		default:
1368 			/* Always print 0's for %pK */
1369 			ptr = NULL;
1370 			break;
1371 		}
1372 		break;
1373 
1374 	case 'N':
1375 		switch (fmt[1]) {
1376 		case 'F':
1377 			return netdev_feature_string(buf, end, ptr, spec);
1378 		}
1379 		break;
1380 	case 'a':
1381 		return address_val(buf, end, ptr, spec, fmt);
1382 	case 'd':
1383 		return dentry_name(buf, end, ptr, spec, fmt);
1384 	case 'D':
1385 		return dentry_name(buf, end,
1386 				   ((const struct file *)ptr)->f_path.dentry,
1387 				   spec, fmt);
1388 	}
1389 	spec.flags |= SMALL;
1390 	if (spec.field_width == -1) {
1391 		spec.field_width = default_width;
1392 		spec.flags |= ZEROPAD;
1393 	}
1394 	spec.base = 16;
1395 
1396 	return number(buf, end, (unsigned long) ptr, spec);
1397 }
1398 
1399 /*
1400  * Helper function to decode printf style format.
1401  * Each call decode a token from the format and return the
1402  * number of characters read (or likely the delta where it wants
1403  * to go on the next call).
1404  * The decoded token is returned through the parameters
1405  *
1406  * 'h', 'l', or 'L' for integer fields
1407  * 'z' support added 23/7/1999 S.H.
1408  * 'z' changed to 'Z' --davidm 1/25/99
1409  * 't' added for ptrdiff_t
1410  *
1411  * @fmt: the format string
1412  * @type of the token returned
1413  * @flags: various flags such as +, -, # tokens..
1414  * @field_width: overwritten width
1415  * @base: base of the number (octal, hex, ...)
1416  * @precision: precision of a number
1417  * @qualifier: qualifier of a number (long, size_t, ...)
1418  */
1419 static noinline_for_stack
1420 int format_decode(const char *fmt, struct printf_spec *spec)
1421 {
1422 	const char *start = fmt;
1423 
1424 	/* we finished early by reading the field width */
1425 	if (spec->type == FORMAT_TYPE_WIDTH) {
1426 		if (spec->field_width < 0) {
1427 			spec->field_width = -spec->field_width;
1428 			spec->flags |= LEFT;
1429 		}
1430 		spec->type = FORMAT_TYPE_NONE;
1431 		goto precision;
1432 	}
1433 
1434 	/* we finished early by reading the precision */
1435 	if (spec->type == FORMAT_TYPE_PRECISION) {
1436 		if (spec->precision < 0)
1437 			spec->precision = 0;
1438 
1439 		spec->type = FORMAT_TYPE_NONE;
1440 		goto qualifier;
1441 	}
1442 
1443 	/* By default */
1444 	spec->type = FORMAT_TYPE_NONE;
1445 
1446 	for (; *fmt ; ++fmt) {
1447 		if (*fmt == '%')
1448 			break;
1449 	}
1450 
1451 	/* Return the current non-format string */
1452 	if (fmt != start || !*fmt)
1453 		return fmt - start;
1454 
1455 	/* Process flags */
1456 	spec->flags = 0;
1457 
1458 	while (1) { /* this also skips first '%' */
1459 		bool found = true;
1460 
1461 		++fmt;
1462 
1463 		switch (*fmt) {
1464 		case '-': spec->flags |= LEFT;    break;
1465 		case '+': spec->flags |= PLUS;    break;
1466 		case ' ': spec->flags |= SPACE;   break;
1467 		case '#': spec->flags |= SPECIAL; break;
1468 		case '0': spec->flags |= ZEROPAD; break;
1469 		default:  found = false;
1470 		}
1471 
1472 		if (!found)
1473 			break;
1474 	}
1475 
1476 	/* get field width */
1477 	spec->field_width = -1;
1478 
1479 	if (isdigit(*fmt))
1480 		spec->field_width = skip_atoi(&fmt);
1481 	else if (*fmt == '*') {
1482 		/* it's the next argument */
1483 		spec->type = FORMAT_TYPE_WIDTH;
1484 		return ++fmt - start;
1485 	}
1486 
1487 precision:
1488 	/* get the precision */
1489 	spec->precision = -1;
1490 	if (*fmt == '.') {
1491 		++fmt;
1492 		if (isdigit(*fmt)) {
1493 			spec->precision = skip_atoi(&fmt);
1494 			if (spec->precision < 0)
1495 				spec->precision = 0;
1496 		} else if (*fmt == '*') {
1497 			/* it's the next argument */
1498 			spec->type = FORMAT_TYPE_PRECISION;
1499 			return ++fmt - start;
1500 		}
1501 	}
1502 
1503 qualifier:
1504 	/* get the conversion qualifier */
1505 	spec->qualifier = -1;
1506 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1507 	    _tolower(*fmt) == 'z' || *fmt == 't') {
1508 		spec->qualifier = *fmt++;
1509 		if (unlikely(spec->qualifier == *fmt)) {
1510 			if (spec->qualifier == 'l') {
1511 				spec->qualifier = 'L';
1512 				++fmt;
1513 			} else if (spec->qualifier == 'h') {
1514 				spec->qualifier = 'H';
1515 				++fmt;
1516 			}
1517 		}
1518 	}
1519 
1520 	/* default base */
1521 	spec->base = 10;
1522 	switch (*fmt) {
1523 	case 'c':
1524 		spec->type = FORMAT_TYPE_CHAR;
1525 		return ++fmt - start;
1526 
1527 	case 's':
1528 		spec->type = FORMAT_TYPE_STR;
1529 		return ++fmt - start;
1530 
1531 	case 'p':
1532 		spec->type = FORMAT_TYPE_PTR;
1533 		return fmt - start;
1534 		/* skip alnum */
1535 
1536 	case 'n':
1537 		spec->type = FORMAT_TYPE_NRCHARS;
1538 		return ++fmt - start;
1539 
1540 	case '%':
1541 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1542 		return ++fmt - start;
1543 
1544 	/* integer number formats - set up the flags and "break" */
1545 	case 'o':
1546 		spec->base = 8;
1547 		break;
1548 
1549 	case 'x':
1550 		spec->flags |= SMALL;
1551 
1552 	case 'X':
1553 		spec->base = 16;
1554 		break;
1555 
1556 	case 'd':
1557 	case 'i':
1558 		spec->flags |= SIGN;
1559 	case 'u':
1560 		break;
1561 
1562 	default:
1563 		spec->type = FORMAT_TYPE_INVALID;
1564 		return fmt - start;
1565 	}
1566 
1567 	if (spec->qualifier == 'L')
1568 		spec->type = FORMAT_TYPE_LONG_LONG;
1569 	else if (spec->qualifier == 'l') {
1570 		if (spec->flags & SIGN)
1571 			spec->type = FORMAT_TYPE_LONG;
1572 		else
1573 			spec->type = FORMAT_TYPE_ULONG;
1574 	} else if (_tolower(spec->qualifier) == 'z') {
1575 		spec->type = FORMAT_TYPE_SIZE_T;
1576 	} else if (spec->qualifier == 't') {
1577 		spec->type = FORMAT_TYPE_PTRDIFF;
1578 	} else if (spec->qualifier == 'H') {
1579 		if (spec->flags & SIGN)
1580 			spec->type = FORMAT_TYPE_BYTE;
1581 		else
1582 			spec->type = FORMAT_TYPE_UBYTE;
1583 	} else if (spec->qualifier == 'h') {
1584 		if (spec->flags & SIGN)
1585 			spec->type = FORMAT_TYPE_SHORT;
1586 		else
1587 			spec->type = FORMAT_TYPE_USHORT;
1588 	} else {
1589 		if (spec->flags & SIGN)
1590 			spec->type = FORMAT_TYPE_INT;
1591 		else
1592 			spec->type = FORMAT_TYPE_UINT;
1593 	}
1594 
1595 	return ++fmt - start;
1596 }
1597 
1598 /**
1599  * vsnprintf - Format a string and place it in a buffer
1600  * @buf: The buffer to place the result into
1601  * @size: The size of the buffer, including the trailing null space
1602  * @fmt: The format string to use
1603  * @args: Arguments for the format string
1604  *
1605  * This function follows C99 vsnprintf, but has some extensions:
1606  * %pS output the name of a text symbol with offset
1607  * %ps output the name of a text symbol without offset
1608  * %pF output the name of a function pointer with its offset
1609  * %pf output the name of a function pointer without its offset
1610  * %pB output the name of a backtrace symbol with its offset
1611  * %pR output the address range in a struct resource with decoded flags
1612  * %pr output the address range in a struct resource with raw flags
1613  * %pM output a 6-byte MAC address with colons
1614  * %pMR output a 6-byte MAC address with colons in reversed order
1615  * %pMF output a 6-byte MAC address with dashes
1616  * %pm output a 6-byte MAC address without colons
1617  * %pmR output a 6-byte MAC address without colons in reversed order
1618  * %pI4 print an IPv4 address without leading zeros
1619  * %pi4 print an IPv4 address with leading zeros
1620  * %pI6 print an IPv6 address with colons
1621  * %pi6 print an IPv6 address without colons
1622  * %pI6c print an IPv6 address as specified by RFC 5952
1623  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1624  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1625  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1626  *   case.
1627  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1628  *           bytes of the input)
1629  * %n is ignored
1630  *
1631  * ** Please update Documentation/printk-formats.txt when making changes **
1632  *
1633  * The return value is the number of characters which would
1634  * be generated for the given input, excluding the trailing
1635  * '\0', as per ISO C99. If you want to have the exact
1636  * number of characters written into @buf as return value
1637  * (not including the trailing '\0'), use vscnprintf(). If the
1638  * return is greater than or equal to @size, the resulting
1639  * string is truncated.
1640  *
1641  * If you're not already dealing with a va_list consider using snprintf().
1642  */
1643 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1644 {
1645 	unsigned long long num;
1646 	char *str, *end;
1647 	struct printf_spec spec = {0};
1648 
1649 	/* Reject out-of-range values early.  Large positive sizes are
1650 	   used for unknown buffer sizes. */
1651 	if (WARN_ON_ONCE((int) size < 0))
1652 		return 0;
1653 
1654 	str = buf;
1655 	end = buf + size;
1656 
1657 	/* Make sure end is always >= buf */
1658 	if (end < buf) {
1659 		end = ((void *)-1);
1660 		size = end - buf;
1661 	}
1662 
1663 	while (*fmt) {
1664 		const char *old_fmt = fmt;
1665 		int read = format_decode(fmt, &spec);
1666 
1667 		fmt += read;
1668 
1669 		switch (spec.type) {
1670 		case FORMAT_TYPE_NONE: {
1671 			int copy = read;
1672 			if (str < end) {
1673 				if (copy > end - str)
1674 					copy = end - str;
1675 				memcpy(str, old_fmt, copy);
1676 			}
1677 			str += read;
1678 			break;
1679 		}
1680 
1681 		case FORMAT_TYPE_WIDTH:
1682 			spec.field_width = va_arg(args, int);
1683 			break;
1684 
1685 		case FORMAT_TYPE_PRECISION:
1686 			spec.precision = va_arg(args, int);
1687 			break;
1688 
1689 		case FORMAT_TYPE_CHAR: {
1690 			char c;
1691 
1692 			if (!(spec.flags & LEFT)) {
1693 				while (--spec.field_width > 0) {
1694 					if (str < end)
1695 						*str = ' ';
1696 					++str;
1697 
1698 				}
1699 			}
1700 			c = (unsigned char) va_arg(args, int);
1701 			if (str < end)
1702 				*str = c;
1703 			++str;
1704 			while (--spec.field_width > 0) {
1705 				if (str < end)
1706 					*str = ' ';
1707 				++str;
1708 			}
1709 			break;
1710 		}
1711 
1712 		case FORMAT_TYPE_STR:
1713 			str = string(str, end, va_arg(args, char *), spec);
1714 			break;
1715 
1716 		case FORMAT_TYPE_PTR:
1717 			str = pointer(fmt+1, str, end, va_arg(args, void *),
1718 				      spec);
1719 			while (isalnum(*fmt))
1720 				fmt++;
1721 			break;
1722 
1723 		case FORMAT_TYPE_PERCENT_CHAR:
1724 			if (str < end)
1725 				*str = '%';
1726 			++str;
1727 			break;
1728 
1729 		case FORMAT_TYPE_INVALID:
1730 			if (str < end)
1731 				*str = '%';
1732 			++str;
1733 			break;
1734 
1735 		case FORMAT_TYPE_NRCHARS: {
1736 			/*
1737 			 * Since %n poses a greater security risk than
1738 			 * utility, ignore %n and skip its argument.
1739 			 */
1740 			void *skip_arg;
1741 
1742 			WARN_ONCE(1, "Please remove ignored %%n in '%s'\n",
1743 					old_fmt);
1744 
1745 			skip_arg = va_arg(args, void *);
1746 			break;
1747 		}
1748 
1749 		default:
1750 			switch (spec.type) {
1751 			case FORMAT_TYPE_LONG_LONG:
1752 				num = va_arg(args, long long);
1753 				break;
1754 			case FORMAT_TYPE_ULONG:
1755 				num = va_arg(args, unsigned long);
1756 				break;
1757 			case FORMAT_TYPE_LONG:
1758 				num = va_arg(args, long);
1759 				break;
1760 			case FORMAT_TYPE_SIZE_T:
1761 				if (spec.flags & SIGN)
1762 					num = va_arg(args, ssize_t);
1763 				else
1764 					num = va_arg(args, size_t);
1765 				break;
1766 			case FORMAT_TYPE_PTRDIFF:
1767 				num = va_arg(args, ptrdiff_t);
1768 				break;
1769 			case FORMAT_TYPE_UBYTE:
1770 				num = (unsigned char) va_arg(args, int);
1771 				break;
1772 			case FORMAT_TYPE_BYTE:
1773 				num = (signed char) va_arg(args, int);
1774 				break;
1775 			case FORMAT_TYPE_USHORT:
1776 				num = (unsigned short) va_arg(args, int);
1777 				break;
1778 			case FORMAT_TYPE_SHORT:
1779 				num = (short) va_arg(args, int);
1780 				break;
1781 			case FORMAT_TYPE_INT:
1782 				num = (int) va_arg(args, int);
1783 				break;
1784 			default:
1785 				num = va_arg(args, unsigned int);
1786 			}
1787 
1788 			str = number(str, end, num, spec);
1789 		}
1790 	}
1791 
1792 	if (size > 0) {
1793 		if (str < end)
1794 			*str = '\0';
1795 		else
1796 			end[-1] = '\0';
1797 	}
1798 
1799 	/* the trailing null byte doesn't count towards the total */
1800 	return str-buf;
1801 
1802 }
1803 EXPORT_SYMBOL(vsnprintf);
1804 
1805 /**
1806  * vscnprintf - Format a string and place it in a buffer
1807  * @buf: The buffer to place the result into
1808  * @size: The size of the buffer, including the trailing null space
1809  * @fmt: The format string to use
1810  * @args: Arguments for the format string
1811  *
1812  * The return value is the number of characters which have been written into
1813  * the @buf not including the trailing '\0'. If @size is == 0 the function
1814  * returns 0.
1815  *
1816  * If you're not already dealing with a va_list consider using scnprintf().
1817  *
1818  * See the vsnprintf() documentation for format string extensions over C99.
1819  */
1820 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1821 {
1822 	int i;
1823 
1824 	i = vsnprintf(buf, size, fmt, args);
1825 
1826 	if (likely(i < size))
1827 		return i;
1828 	if (size != 0)
1829 		return size - 1;
1830 	return 0;
1831 }
1832 EXPORT_SYMBOL(vscnprintf);
1833 
1834 /**
1835  * snprintf - Format a string and place it in a buffer
1836  * @buf: The buffer to place the result into
1837  * @size: The size of the buffer, including the trailing null space
1838  * @fmt: The format string to use
1839  * @...: Arguments for the format string
1840  *
1841  * The return value is the number of characters which would be
1842  * generated for the given input, excluding the trailing null,
1843  * as per ISO C99.  If the return is greater than or equal to
1844  * @size, the resulting string is truncated.
1845  *
1846  * See the vsnprintf() documentation for format string extensions over C99.
1847  */
1848 int snprintf(char *buf, size_t size, const char *fmt, ...)
1849 {
1850 	va_list args;
1851 	int i;
1852 
1853 	va_start(args, fmt);
1854 	i = vsnprintf(buf, size, fmt, args);
1855 	va_end(args);
1856 
1857 	return i;
1858 }
1859 EXPORT_SYMBOL(snprintf);
1860 
1861 /**
1862  * scnprintf - Format a string and place it in a buffer
1863  * @buf: The buffer to place the result into
1864  * @size: The size of the buffer, including the trailing null space
1865  * @fmt: The format string to use
1866  * @...: Arguments for the format string
1867  *
1868  * The return value is the number of characters written into @buf not including
1869  * the trailing '\0'. If @size is == 0 the function returns 0.
1870  */
1871 
1872 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1873 {
1874 	va_list args;
1875 	int i;
1876 
1877 	va_start(args, fmt);
1878 	i = vscnprintf(buf, size, fmt, args);
1879 	va_end(args);
1880 
1881 	return i;
1882 }
1883 EXPORT_SYMBOL(scnprintf);
1884 
1885 /**
1886  * vsprintf - Format a string and place it in a buffer
1887  * @buf: The buffer to place the result into
1888  * @fmt: The format string to use
1889  * @args: Arguments for the format string
1890  *
1891  * The function returns the number of characters written
1892  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1893  * buffer overflows.
1894  *
1895  * If you're not already dealing with a va_list consider using sprintf().
1896  *
1897  * See the vsnprintf() documentation for format string extensions over C99.
1898  */
1899 int vsprintf(char *buf, const char *fmt, va_list args)
1900 {
1901 	return vsnprintf(buf, INT_MAX, fmt, args);
1902 }
1903 EXPORT_SYMBOL(vsprintf);
1904 
1905 /**
1906  * sprintf - Format a string and place it in a buffer
1907  * @buf: The buffer to place the result into
1908  * @fmt: The format string to use
1909  * @...: Arguments for the format string
1910  *
1911  * The function returns the number of characters written
1912  * into @buf. Use snprintf() or scnprintf() in order to avoid
1913  * buffer overflows.
1914  *
1915  * See the vsnprintf() documentation for format string extensions over C99.
1916  */
1917 int sprintf(char *buf, const char *fmt, ...)
1918 {
1919 	va_list args;
1920 	int i;
1921 
1922 	va_start(args, fmt);
1923 	i = vsnprintf(buf, INT_MAX, fmt, args);
1924 	va_end(args);
1925 
1926 	return i;
1927 }
1928 EXPORT_SYMBOL(sprintf);
1929 
1930 #ifdef CONFIG_BINARY_PRINTF
1931 /*
1932  * bprintf service:
1933  * vbin_printf() - VA arguments to binary data
1934  * bstr_printf() - Binary data to text string
1935  */
1936 
1937 /**
1938  * vbin_printf - Parse a format string and place args' binary value in a buffer
1939  * @bin_buf: The buffer to place args' binary value
1940  * @size: The size of the buffer(by words(32bits), not characters)
1941  * @fmt: The format string to use
1942  * @args: Arguments for the format string
1943  *
1944  * The format follows C99 vsnprintf, except %n is ignored, and its argument
1945  * is skiped.
1946  *
1947  * The return value is the number of words(32bits) which would be generated for
1948  * the given input.
1949  *
1950  * NOTE:
1951  * If the return value is greater than @size, the resulting bin_buf is NOT
1952  * valid for bstr_printf().
1953  */
1954 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1955 {
1956 	struct printf_spec spec = {0};
1957 	char *str, *end;
1958 
1959 	str = (char *)bin_buf;
1960 	end = (char *)(bin_buf + size);
1961 
1962 #define save_arg(type)							\
1963 do {									\
1964 	if (sizeof(type) == 8) {					\
1965 		unsigned long long value;				\
1966 		str = PTR_ALIGN(str, sizeof(u32));			\
1967 		value = va_arg(args, unsigned long long);		\
1968 		if (str + sizeof(type) <= end) {			\
1969 			*(u32 *)str = *(u32 *)&value;			\
1970 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
1971 		}							\
1972 	} else {							\
1973 		unsigned long value;					\
1974 		str = PTR_ALIGN(str, sizeof(type));			\
1975 		value = va_arg(args, int);				\
1976 		if (str + sizeof(type) <= end)				\
1977 			*(typeof(type) *)str = (type)value;		\
1978 	}								\
1979 	str += sizeof(type);						\
1980 } while (0)
1981 
1982 	while (*fmt) {
1983 		int read = format_decode(fmt, &spec);
1984 
1985 		fmt += read;
1986 
1987 		switch (spec.type) {
1988 		case FORMAT_TYPE_NONE:
1989 		case FORMAT_TYPE_INVALID:
1990 		case FORMAT_TYPE_PERCENT_CHAR:
1991 			break;
1992 
1993 		case FORMAT_TYPE_WIDTH:
1994 		case FORMAT_TYPE_PRECISION:
1995 			save_arg(int);
1996 			break;
1997 
1998 		case FORMAT_TYPE_CHAR:
1999 			save_arg(char);
2000 			break;
2001 
2002 		case FORMAT_TYPE_STR: {
2003 			const char *save_str = va_arg(args, char *);
2004 			size_t len;
2005 
2006 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2007 					|| (unsigned long)save_str < PAGE_SIZE)
2008 				save_str = "(null)";
2009 			len = strlen(save_str) + 1;
2010 			if (str + len < end)
2011 				memcpy(str, save_str, len);
2012 			str += len;
2013 			break;
2014 		}
2015 
2016 		case FORMAT_TYPE_PTR:
2017 			save_arg(void *);
2018 			/* skip all alphanumeric pointer suffixes */
2019 			while (isalnum(*fmt))
2020 				fmt++;
2021 			break;
2022 
2023 		case FORMAT_TYPE_NRCHARS: {
2024 			/* skip %n 's argument */
2025 			u8 qualifier = spec.qualifier;
2026 			void *skip_arg;
2027 			if (qualifier == 'l')
2028 				skip_arg = va_arg(args, long *);
2029 			else if (_tolower(qualifier) == 'z')
2030 				skip_arg = va_arg(args, size_t *);
2031 			else
2032 				skip_arg = va_arg(args, int *);
2033 			break;
2034 		}
2035 
2036 		default:
2037 			switch (spec.type) {
2038 
2039 			case FORMAT_TYPE_LONG_LONG:
2040 				save_arg(long long);
2041 				break;
2042 			case FORMAT_TYPE_ULONG:
2043 			case FORMAT_TYPE_LONG:
2044 				save_arg(unsigned long);
2045 				break;
2046 			case FORMAT_TYPE_SIZE_T:
2047 				save_arg(size_t);
2048 				break;
2049 			case FORMAT_TYPE_PTRDIFF:
2050 				save_arg(ptrdiff_t);
2051 				break;
2052 			case FORMAT_TYPE_UBYTE:
2053 			case FORMAT_TYPE_BYTE:
2054 				save_arg(char);
2055 				break;
2056 			case FORMAT_TYPE_USHORT:
2057 			case FORMAT_TYPE_SHORT:
2058 				save_arg(short);
2059 				break;
2060 			default:
2061 				save_arg(int);
2062 			}
2063 		}
2064 	}
2065 
2066 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2067 #undef save_arg
2068 }
2069 EXPORT_SYMBOL_GPL(vbin_printf);
2070 
2071 /**
2072  * bstr_printf - Format a string from binary arguments and place it in a buffer
2073  * @buf: The buffer to place the result into
2074  * @size: The size of the buffer, including the trailing null space
2075  * @fmt: The format string to use
2076  * @bin_buf: Binary arguments for the format string
2077  *
2078  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2079  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2080  * a binary buffer that generated by vbin_printf.
2081  *
2082  * The format follows C99 vsnprintf, but has some extensions:
2083  *  see vsnprintf comment for details.
2084  *
2085  * The return value is the number of characters which would
2086  * be generated for the given input, excluding the trailing
2087  * '\0', as per ISO C99. If you want to have the exact
2088  * number of characters written into @buf as return value
2089  * (not including the trailing '\0'), use vscnprintf(). If the
2090  * return is greater than or equal to @size, the resulting
2091  * string is truncated.
2092  */
2093 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2094 {
2095 	struct printf_spec spec = {0};
2096 	char *str, *end;
2097 	const char *args = (const char *)bin_buf;
2098 
2099 	if (WARN_ON_ONCE((int) size < 0))
2100 		return 0;
2101 
2102 	str = buf;
2103 	end = buf + size;
2104 
2105 #define get_arg(type)							\
2106 ({									\
2107 	typeof(type) value;						\
2108 	if (sizeof(type) == 8) {					\
2109 		args = PTR_ALIGN(args, sizeof(u32));			\
2110 		*(u32 *)&value = *(u32 *)args;				\
2111 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2112 	} else {							\
2113 		args = PTR_ALIGN(args, sizeof(type));			\
2114 		value = *(typeof(type) *)args;				\
2115 	}								\
2116 	args += sizeof(type);						\
2117 	value;								\
2118 })
2119 
2120 	/* Make sure end is always >= buf */
2121 	if (end < buf) {
2122 		end = ((void *)-1);
2123 		size = end - buf;
2124 	}
2125 
2126 	while (*fmt) {
2127 		const char *old_fmt = fmt;
2128 		int read = format_decode(fmt, &spec);
2129 
2130 		fmt += read;
2131 
2132 		switch (spec.type) {
2133 		case FORMAT_TYPE_NONE: {
2134 			int copy = read;
2135 			if (str < end) {
2136 				if (copy > end - str)
2137 					copy = end - str;
2138 				memcpy(str, old_fmt, copy);
2139 			}
2140 			str += read;
2141 			break;
2142 		}
2143 
2144 		case FORMAT_TYPE_WIDTH:
2145 			spec.field_width = get_arg(int);
2146 			break;
2147 
2148 		case FORMAT_TYPE_PRECISION:
2149 			spec.precision = get_arg(int);
2150 			break;
2151 
2152 		case FORMAT_TYPE_CHAR: {
2153 			char c;
2154 
2155 			if (!(spec.flags & LEFT)) {
2156 				while (--spec.field_width > 0) {
2157 					if (str < end)
2158 						*str = ' ';
2159 					++str;
2160 				}
2161 			}
2162 			c = (unsigned char) get_arg(char);
2163 			if (str < end)
2164 				*str = c;
2165 			++str;
2166 			while (--spec.field_width > 0) {
2167 				if (str < end)
2168 					*str = ' ';
2169 				++str;
2170 			}
2171 			break;
2172 		}
2173 
2174 		case FORMAT_TYPE_STR: {
2175 			const char *str_arg = args;
2176 			args += strlen(str_arg) + 1;
2177 			str = string(str, end, (char *)str_arg, spec);
2178 			break;
2179 		}
2180 
2181 		case FORMAT_TYPE_PTR:
2182 			str = pointer(fmt+1, str, end, get_arg(void *), spec);
2183 			while (isalnum(*fmt))
2184 				fmt++;
2185 			break;
2186 
2187 		case FORMAT_TYPE_PERCENT_CHAR:
2188 		case FORMAT_TYPE_INVALID:
2189 			if (str < end)
2190 				*str = '%';
2191 			++str;
2192 			break;
2193 
2194 		case FORMAT_TYPE_NRCHARS:
2195 			/* skip */
2196 			break;
2197 
2198 		default: {
2199 			unsigned long long num;
2200 
2201 			switch (spec.type) {
2202 
2203 			case FORMAT_TYPE_LONG_LONG:
2204 				num = get_arg(long long);
2205 				break;
2206 			case FORMAT_TYPE_ULONG:
2207 			case FORMAT_TYPE_LONG:
2208 				num = get_arg(unsigned long);
2209 				break;
2210 			case FORMAT_TYPE_SIZE_T:
2211 				num = get_arg(size_t);
2212 				break;
2213 			case FORMAT_TYPE_PTRDIFF:
2214 				num = get_arg(ptrdiff_t);
2215 				break;
2216 			case FORMAT_TYPE_UBYTE:
2217 				num = get_arg(unsigned char);
2218 				break;
2219 			case FORMAT_TYPE_BYTE:
2220 				num = get_arg(signed char);
2221 				break;
2222 			case FORMAT_TYPE_USHORT:
2223 				num = get_arg(unsigned short);
2224 				break;
2225 			case FORMAT_TYPE_SHORT:
2226 				num = get_arg(short);
2227 				break;
2228 			case FORMAT_TYPE_UINT:
2229 				num = get_arg(unsigned int);
2230 				break;
2231 			default:
2232 				num = get_arg(int);
2233 			}
2234 
2235 			str = number(str, end, num, spec);
2236 		} /* default: */
2237 		} /* switch(spec.type) */
2238 	} /* while(*fmt) */
2239 
2240 	if (size > 0) {
2241 		if (str < end)
2242 			*str = '\0';
2243 		else
2244 			end[-1] = '\0';
2245 	}
2246 
2247 #undef get_arg
2248 
2249 	/* the trailing null byte doesn't count towards the total */
2250 	return str - buf;
2251 }
2252 EXPORT_SYMBOL_GPL(bstr_printf);
2253 
2254 /**
2255  * bprintf - Parse a format string and place args' binary value in a buffer
2256  * @bin_buf: The buffer to place args' binary value
2257  * @size: The size of the buffer(by words(32bits), not characters)
2258  * @fmt: The format string to use
2259  * @...: Arguments for the format string
2260  *
2261  * The function returns the number of words(u32) written
2262  * into @bin_buf.
2263  */
2264 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2265 {
2266 	va_list args;
2267 	int ret;
2268 
2269 	va_start(args, fmt);
2270 	ret = vbin_printf(bin_buf, size, fmt, args);
2271 	va_end(args);
2272 
2273 	return ret;
2274 }
2275 EXPORT_SYMBOL_GPL(bprintf);
2276 
2277 #endif /* CONFIG_BINARY_PRINTF */
2278 
2279 /**
2280  * vsscanf - Unformat a buffer into a list of arguments
2281  * @buf:	input buffer
2282  * @fmt:	format of buffer
2283  * @args:	arguments
2284  */
2285 int vsscanf(const char *buf, const char *fmt, va_list args)
2286 {
2287 	const char *str = buf;
2288 	char *next;
2289 	char digit;
2290 	int num = 0;
2291 	u8 qualifier;
2292 	unsigned int base;
2293 	union {
2294 		long long s;
2295 		unsigned long long u;
2296 	} val;
2297 	s16 field_width;
2298 	bool is_sign;
2299 
2300 	while (*fmt) {
2301 		/* skip any white space in format */
2302 		/* white space in format matchs any amount of
2303 		 * white space, including none, in the input.
2304 		 */
2305 		if (isspace(*fmt)) {
2306 			fmt = skip_spaces(++fmt);
2307 			str = skip_spaces(str);
2308 		}
2309 
2310 		/* anything that is not a conversion must match exactly */
2311 		if (*fmt != '%' && *fmt) {
2312 			if (*fmt++ != *str++)
2313 				break;
2314 			continue;
2315 		}
2316 
2317 		if (!*fmt)
2318 			break;
2319 		++fmt;
2320 
2321 		/* skip this conversion.
2322 		 * advance both strings to next white space
2323 		 */
2324 		if (*fmt == '*') {
2325 			if (!*str)
2326 				break;
2327 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
2328 				fmt++;
2329 			while (!isspace(*str) && *str)
2330 				str++;
2331 			continue;
2332 		}
2333 
2334 		/* get field width */
2335 		field_width = -1;
2336 		if (isdigit(*fmt)) {
2337 			field_width = skip_atoi(&fmt);
2338 			if (field_width <= 0)
2339 				break;
2340 		}
2341 
2342 		/* get conversion qualifier */
2343 		qualifier = -1;
2344 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2345 		    _tolower(*fmt) == 'z') {
2346 			qualifier = *fmt++;
2347 			if (unlikely(qualifier == *fmt)) {
2348 				if (qualifier == 'h') {
2349 					qualifier = 'H';
2350 					fmt++;
2351 				} else if (qualifier == 'l') {
2352 					qualifier = 'L';
2353 					fmt++;
2354 				}
2355 			}
2356 		}
2357 
2358 		if (!*fmt)
2359 			break;
2360 
2361 		if (*fmt == 'n') {
2362 			/* return number of characters read so far */
2363 			*va_arg(args, int *) = str - buf;
2364 			++fmt;
2365 			continue;
2366 		}
2367 
2368 		if (!*str)
2369 			break;
2370 
2371 		base = 10;
2372 		is_sign = 0;
2373 
2374 		switch (*fmt++) {
2375 		case 'c':
2376 		{
2377 			char *s = (char *)va_arg(args, char*);
2378 			if (field_width == -1)
2379 				field_width = 1;
2380 			do {
2381 				*s++ = *str++;
2382 			} while (--field_width > 0 && *str);
2383 			num++;
2384 		}
2385 		continue;
2386 		case 's':
2387 		{
2388 			char *s = (char *)va_arg(args, char *);
2389 			if (field_width == -1)
2390 				field_width = SHRT_MAX;
2391 			/* first, skip leading white space in buffer */
2392 			str = skip_spaces(str);
2393 
2394 			/* now copy until next white space */
2395 			while (*str && !isspace(*str) && field_width--)
2396 				*s++ = *str++;
2397 			*s = '\0';
2398 			num++;
2399 		}
2400 		continue;
2401 		case 'o':
2402 			base = 8;
2403 			break;
2404 		case 'x':
2405 		case 'X':
2406 			base = 16;
2407 			break;
2408 		case 'i':
2409 			base = 0;
2410 		case 'd':
2411 			is_sign = 1;
2412 		case 'u':
2413 			break;
2414 		case '%':
2415 			/* looking for '%' in str */
2416 			if (*str++ != '%')
2417 				return num;
2418 			continue;
2419 		default:
2420 			/* invalid format; stop here */
2421 			return num;
2422 		}
2423 
2424 		/* have some sort of integer conversion.
2425 		 * first, skip white space in buffer.
2426 		 */
2427 		str = skip_spaces(str);
2428 
2429 		digit = *str;
2430 		if (is_sign && digit == '-')
2431 			digit = *(str + 1);
2432 
2433 		if (!digit
2434 		    || (base == 16 && !isxdigit(digit))
2435 		    || (base == 10 && !isdigit(digit))
2436 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
2437 		    || (base == 0 && !isdigit(digit)))
2438 			break;
2439 
2440 		if (is_sign)
2441 			val.s = qualifier != 'L' ?
2442 				simple_strtol(str, &next, base) :
2443 				simple_strtoll(str, &next, base);
2444 		else
2445 			val.u = qualifier != 'L' ?
2446 				simple_strtoul(str, &next, base) :
2447 				simple_strtoull(str, &next, base);
2448 
2449 		if (field_width > 0 && next - str > field_width) {
2450 			if (base == 0)
2451 				_parse_integer_fixup_radix(str, &base);
2452 			while (next - str > field_width) {
2453 				if (is_sign)
2454 					val.s = div_s64(val.s, base);
2455 				else
2456 					val.u = div_u64(val.u, base);
2457 				--next;
2458 			}
2459 		}
2460 
2461 		switch (qualifier) {
2462 		case 'H':	/* that's 'hh' in format */
2463 			if (is_sign)
2464 				*va_arg(args, signed char *) = val.s;
2465 			else
2466 				*va_arg(args, unsigned char *) = val.u;
2467 			break;
2468 		case 'h':
2469 			if (is_sign)
2470 				*va_arg(args, short *) = val.s;
2471 			else
2472 				*va_arg(args, unsigned short *) = val.u;
2473 			break;
2474 		case 'l':
2475 			if (is_sign)
2476 				*va_arg(args, long *) = val.s;
2477 			else
2478 				*va_arg(args, unsigned long *) = val.u;
2479 			break;
2480 		case 'L':
2481 			if (is_sign)
2482 				*va_arg(args, long long *) = val.s;
2483 			else
2484 				*va_arg(args, unsigned long long *) = val.u;
2485 			break;
2486 		case 'Z':
2487 		case 'z':
2488 			*va_arg(args, size_t *) = val.u;
2489 			break;
2490 		default:
2491 			if (is_sign)
2492 				*va_arg(args, int *) = val.s;
2493 			else
2494 				*va_arg(args, unsigned int *) = val.u;
2495 			break;
2496 		}
2497 		num++;
2498 
2499 		if (!next)
2500 			break;
2501 		str = next;
2502 	}
2503 
2504 	return num;
2505 }
2506 EXPORT_SYMBOL(vsscanf);
2507 
2508 /**
2509  * sscanf - Unformat a buffer into a list of arguments
2510  * @buf:	input buffer
2511  * @fmt:	formatting of buffer
2512  * @...:	resulting arguments
2513  */
2514 int sscanf(const char *buf, const char *fmt, ...)
2515 {
2516 	va_list args;
2517 	int i;
2518 
2519 	va_start(args, fmt);
2520 	i = vsscanf(buf, fmt, args);
2521 	va_end(args);
2522 
2523 	return i;
2524 }
2525 EXPORT_SYMBOL(sscanf);
2526