xref: /openbmc/linux/lib/vsprintf.c (revision 609e478b)
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 <linux/string_helpers.h>
37 #include "kstrtox.h"
38 
39 /**
40  * simple_strtoull - convert a string to an unsigned long long
41  * @cp: The start of the string
42  * @endp: A pointer to the end of the parsed string will be placed here
43  * @base: The number base to use
44  *
45  * This function is obsolete. Please use kstrtoull instead.
46  */
47 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
48 {
49 	unsigned long long result;
50 	unsigned int rv;
51 
52 	cp = _parse_integer_fixup_radix(cp, &base);
53 	rv = _parse_integer(cp, base, &result);
54 	/* FIXME */
55 	cp += (rv & ~KSTRTOX_OVERFLOW);
56 
57 	if (endp)
58 		*endp = (char *)cp;
59 
60 	return result;
61 }
62 EXPORT_SYMBOL(simple_strtoull);
63 
64 /**
65  * simple_strtoul - convert a string to an unsigned long
66  * @cp: The start of the string
67  * @endp: A pointer to the end of the parsed string will be placed here
68  * @base: The number base to use
69  *
70  * This function is obsolete. Please use kstrtoul instead.
71  */
72 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
73 {
74 	return simple_strtoull(cp, endp, base);
75 }
76 EXPORT_SYMBOL(simple_strtoul);
77 
78 /**
79  * simple_strtol - convert a string to a signed long
80  * @cp: The start of the string
81  * @endp: A pointer to the end of the parsed string will be placed here
82  * @base: The number base to use
83  *
84  * This function is obsolete. Please use kstrtol instead.
85  */
86 long simple_strtol(const char *cp, char **endp, unsigned int base)
87 {
88 	if (*cp == '-')
89 		return -simple_strtoul(cp + 1, endp, base);
90 
91 	return simple_strtoul(cp, endp, base);
92 }
93 EXPORT_SYMBOL(simple_strtol);
94 
95 /**
96  * simple_strtoll - convert a string to a signed long long
97  * @cp: The start of the string
98  * @endp: A pointer to the end of the parsed string will be placed here
99  * @base: The number base to use
100  *
101  * This function is obsolete. Please use kstrtoll instead.
102  */
103 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
104 {
105 	if (*cp == '-')
106 		return -simple_strtoull(cp + 1, endp, base);
107 
108 	return simple_strtoull(cp, endp, base);
109 }
110 EXPORT_SYMBOL(simple_strtoll);
111 
112 static noinline_for_stack
113 int skip_atoi(const char **s)
114 {
115 	int i = 0;
116 
117 	while (isdigit(**s))
118 		i = i*10 + *((*s)++) - '0';
119 
120 	return i;
121 }
122 
123 /* Decimal conversion is by far the most typical, and is used
124  * for /proc and /sys data. This directly impacts e.g. top performance
125  * with many processes running. We optimize it for speed
126  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
127  * (with permission from the author, Douglas W. Jones).
128  */
129 
130 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
131 /* Formats correctly any integer in [0, 999999999] */
132 static noinline_for_stack
133 char *put_dec_full9(char *buf, unsigned q)
134 {
135 	unsigned r;
136 
137 	/*
138 	 * Possible ways to approx. divide by 10
139 	 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
140 	 * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
141 	 * (x * 0x6667) >> 18     x <      43699
142 	 * (x * 0x3334) >> 17     x <      16389
143 	 * (x * 0x199a) >> 16     x <      16389
144 	 * (x * 0x0ccd) >> 15     x <      16389
145 	 * (x * 0x0667) >> 14     x <       2739
146 	 * (x * 0x0334) >> 13     x <       1029
147 	 * (x * 0x019a) >> 12     x <       1029
148 	 * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
149 	 * (x * 0x0067) >> 10     x <        179
150 	 * (x * 0x0034) >>  9     x <         69 same
151 	 * (x * 0x001a) >>  8     x <         69 same
152 	 * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
153 	 * (x * 0x0007) >>  6     x <         19
154 	 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
155 	 */
156 	r      = (q * (uint64_t)0x1999999a) >> 32;
157 	*buf++ = (q - 10 * r) + '0'; /* 1 */
158 	q      = (r * (uint64_t)0x1999999a) >> 32;
159 	*buf++ = (r - 10 * q) + '0'; /* 2 */
160 	r      = (q * (uint64_t)0x1999999a) >> 32;
161 	*buf++ = (q - 10 * r) + '0'; /* 3 */
162 	q      = (r * (uint64_t)0x1999999a) >> 32;
163 	*buf++ = (r - 10 * q) + '0'; /* 4 */
164 	r      = (q * (uint64_t)0x1999999a) >> 32;
165 	*buf++ = (q - 10 * r) + '0'; /* 5 */
166 	/* Now value is under 10000, can avoid 64-bit multiply */
167 	q      = (r * 0x199a) >> 16;
168 	*buf++ = (r - 10 * q)  + '0'; /* 6 */
169 	r      = (q * 0xcd) >> 11;
170 	*buf++ = (q - 10 * r)  + '0'; /* 7 */
171 	q      = (r * 0xcd) >> 11;
172 	*buf++ = (r - 10 * q) + '0'; /* 8 */
173 	*buf++ = q + '0'; /* 9 */
174 	return buf;
175 }
176 #endif
177 
178 /* Similar to above but do not pad with zeros.
179  * Code can be easily arranged to print 9 digits too, but our callers
180  * always call put_dec_full9() instead when the number has 9 decimal digits.
181  */
182 static noinline_for_stack
183 char *put_dec_trunc8(char *buf, unsigned r)
184 {
185 	unsigned q;
186 
187 	/* Copy of previous function's body with added early returns */
188 	while (r >= 10000) {
189 		q = r + '0';
190 		r  = (r * (uint64_t)0x1999999a) >> 32;
191 		*buf++ = q - 10*r;
192 	}
193 
194 	q      = (r * 0x199a) >> 16;	/* r <= 9999 */
195 	*buf++ = (r - 10 * q)  + '0';
196 	if (q == 0)
197 		return buf;
198 	r      = (q * 0xcd) >> 11;	/* q <= 999 */
199 	*buf++ = (q - 10 * r)  + '0';
200 	if (r == 0)
201 		return buf;
202 	q      = (r * 0xcd) >> 11;	/* r <= 99 */
203 	*buf++ = (r - 10 * q) + '0';
204 	if (q == 0)
205 		return buf;
206 	*buf++ = q + '0';		 /* q <= 9 */
207 	return buf;
208 }
209 
210 /* There are two algorithms to print larger numbers.
211  * One is generic: divide by 1000000000 and repeatedly print
212  * groups of (up to) 9 digits. It's conceptually simple,
213  * but requires a (unsigned long long) / 1000000000 division.
214  *
215  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
216  * manipulates them cleverly and generates groups of 4 decimal digits.
217  * It so happens that it does NOT require long long division.
218  *
219  * If long is > 32 bits, division of 64-bit values is relatively easy,
220  * and we will use the first algorithm.
221  * If long long is > 64 bits (strange architecture with VERY large long long),
222  * second algorithm can't be used, and we again use the first one.
223  *
224  * Else (if long is 32 bits and long long is 64 bits) we use second one.
225  */
226 
227 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
228 
229 /* First algorithm: generic */
230 
231 static
232 char *put_dec(char *buf, unsigned long long n)
233 {
234 	if (n >= 100*1000*1000) {
235 		while (n >= 1000*1000*1000)
236 			buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
237 		if (n >= 100*1000*1000)
238 			return put_dec_full9(buf, n);
239 	}
240 	return put_dec_trunc8(buf, n);
241 }
242 
243 #else
244 
245 /* Second algorithm: valid only for 64-bit long longs */
246 
247 /* See comment in put_dec_full9 for choice of constants */
248 static noinline_for_stack
249 void put_dec_full4(char *buf, unsigned q)
250 {
251 	unsigned r;
252 	r      = (q * 0xccd) >> 15;
253 	buf[0] = (q - 10 * r) + '0';
254 	q      = (r * 0xcd) >> 11;
255 	buf[1] = (r - 10 * q)  + '0';
256 	r      = (q * 0xcd) >> 11;
257 	buf[2] = (q - 10 * r)  + '0';
258 	buf[3] = r + '0';
259 }
260 
261 /*
262  * Call put_dec_full4 on x % 10000, return x / 10000.
263  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
264  * holds for all x < 1,128,869,999.  The largest value this
265  * helper will ever be asked to convert is 1,125,520,955.
266  * (d1 in the put_dec code, assuming n is all-ones).
267  */
268 static
269 unsigned put_dec_helper4(char *buf, unsigned x)
270 {
271         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
272 
273         put_dec_full4(buf, x - q * 10000);
274         return q;
275 }
276 
277 /* Based on code by Douglas W. Jones found at
278  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
279  * (with permission from the author).
280  * Performs no 64-bit division and hence should be fast on 32-bit machines.
281  */
282 static
283 char *put_dec(char *buf, unsigned long long n)
284 {
285 	uint32_t d3, d2, d1, q, h;
286 
287 	if (n < 100*1000*1000)
288 		return put_dec_trunc8(buf, n);
289 
290 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
291 	h   = (n >> 32);
292 	d2  = (h      ) & 0xffff;
293 	d3  = (h >> 16); /* implicit "& 0xffff" */
294 
295 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
296 	q = put_dec_helper4(buf, q);
297 
298 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
299 	q = put_dec_helper4(buf+4, q);
300 
301 	q += 4749 * d3 + 42 * d2;
302 	q = put_dec_helper4(buf+8, q);
303 
304 	q += 281 * d3;
305 	buf += 12;
306 	if (q)
307 		buf = put_dec_trunc8(buf, q);
308 	else while (buf[-1] == '0')
309 		--buf;
310 
311 	return buf;
312 }
313 
314 #endif
315 
316 /*
317  * Convert passed number to decimal string.
318  * Returns the length of string.  On buffer overflow, returns 0.
319  *
320  * If speed is not important, use snprintf(). It's easy to read the code.
321  */
322 int num_to_str(char *buf, int size, unsigned long long num)
323 {
324 	char tmp[sizeof(num) * 3];
325 	int idx, len;
326 
327 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
328 	if (num <= 9) {
329 		tmp[0] = '0' + num;
330 		len = 1;
331 	} else {
332 		len = put_dec(tmp, num) - tmp;
333 	}
334 
335 	if (len > size)
336 		return 0;
337 	for (idx = 0; idx < len; ++idx)
338 		buf[idx] = tmp[len - idx - 1];
339 	return len;
340 }
341 
342 #define ZEROPAD	1		/* pad with zero */
343 #define SIGN	2		/* unsigned/signed long */
344 #define PLUS	4		/* show plus */
345 #define SPACE	8		/* space if plus */
346 #define LEFT	16		/* left justified */
347 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
348 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
349 
350 enum format_type {
351 	FORMAT_TYPE_NONE, /* Just a string part */
352 	FORMAT_TYPE_WIDTH,
353 	FORMAT_TYPE_PRECISION,
354 	FORMAT_TYPE_CHAR,
355 	FORMAT_TYPE_STR,
356 	FORMAT_TYPE_PTR,
357 	FORMAT_TYPE_PERCENT_CHAR,
358 	FORMAT_TYPE_INVALID,
359 	FORMAT_TYPE_LONG_LONG,
360 	FORMAT_TYPE_ULONG,
361 	FORMAT_TYPE_LONG,
362 	FORMAT_TYPE_UBYTE,
363 	FORMAT_TYPE_BYTE,
364 	FORMAT_TYPE_USHORT,
365 	FORMAT_TYPE_SHORT,
366 	FORMAT_TYPE_UINT,
367 	FORMAT_TYPE_INT,
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 	if (decode && res->flags & IORESOURCE_UNSET) {
723 		p = string(p, pend, "size ", str_spec);
724 		p = number(p, pend, resource_size(res), *specp);
725 	} else {
726 		p = number(p, pend, res->start, *specp);
727 		if (res->start != res->end) {
728 			*p++ = '-';
729 			p = number(p, pend, res->end, *specp);
730 		}
731 	}
732 	if (decode) {
733 		if (res->flags & IORESOURCE_MEM_64)
734 			p = string(p, pend, " 64bit", str_spec);
735 		if (res->flags & IORESOURCE_PREFETCH)
736 			p = string(p, pend, " pref", str_spec);
737 		if (res->flags & IORESOURCE_WINDOW)
738 			p = string(p, pend, " window", str_spec);
739 		if (res->flags & IORESOURCE_DISABLED)
740 			p = string(p, pend, " disabled", str_spec);
741 	} else {
742 		p = string(p, pend, " flags ", str_spec);
743 		p = number(p, pend, res->flags, flag_spec);
744 	}
745 	*p++ = ']';
746 	*p = '\0';
747 
748 	return string(buf, end, sym, spec);
749 }
750 
751 static noinline_for_stack
752 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
753 		 const char *fmt)
754 {
755 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
756 				   negative value, fallback to the default */
757 	char separator;
758 
759 	if (spec.field_width == 0)
760 		/* nothing to print */
761 		return buf;
762 
763 	if (ZERO_OR_NULL_PTR(addr))
764 		/* NULL pointer */
765 		return string(buf, end, NULL, spec);
766 
767 	switch (fmt[1]) {
768 	case 'C':
769 		separator = ':';
770 		break;
771 	case 'D':
772 		separator = '-';
773 		break;
774 	case 'N':
775 		separator = 0;
776 		break;
777 	default:
778 		separator = ' ';
779 		break;
780 	}
781 
782 	if (spec.field_width > 0)
783 		len = min_t(int, spec.field_width, 64);
784 
785 	for (i = 0; i < len && buf < end - 1; i++) {
786 		buf = hex_byte_pack(buf, addr[i]);
787 
788 		if (buf < end && separator && i != len - 1)
789 			*buf++ = separator;
790 	}
791 
792 	return buf;
793 }
794 
795 static noinline_for_stack
796 char *mac_address_string(char *buf, char *end, u8 *addr,
797 			 struct printf_spec spec, const char *fmt)
798 {
799 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
800 	char *p = mac_addr;
801 	int i;
802 	char separator;
803 	bool reversed = false;
804 
805 	switch (fmt[1]) {
806 	case 'F':
807 		separator = '-';
808 		break;
809 
810 	case 'R':
811 		reversed = true;
812 		/* fall through */
813 
814 	default:
815 		separator = ':';
816 		break;
817 	}
818 
819 	for (i = 0; i < 6; i++) {
820 		if (reversed)
821 			p = hex_byte_pack(p, addr[5 - i]);
822 		else
823 			p = hex_byte_pack(p, addr[i]);
824 
825 		if (fmt[0] == 'M' && i != 5)
826 			*p++ = separator;
827 	}
828 	*p = '\0';
829 
830 	return string(buf, end, mac_addr, spec);
831 }
832 
833 static noinline_for_stack
834 char *ip4_string(char *p, const u8 *addr, const char *fmt)
835 {
836 	int i;
837 	bool leading_zeros = (fmt[0] == 'i');
838 	int index;
839 	int step;
840 
841 	switch (fmt[2]) {
842 	case 'h':
843 #ifdef __BIG_ENDIAN
844 		index = 0;
845 		step = 1;
846 #else
847 		index = 3;
848 		step = -1;
849 #endif
850 		break;
851 	case 'l':
852 		index = 3;
853 		step = -1;
854 		break;
855 	case 'n':
856 	case 'b':
857 	default:
858 		index = 0;
859 		step = 1;
860 		break;
861 	}
862 	for (i = 0; i < 4; i++) {
863 		char temp[3];	/* hold each IP quad in reverse order */
864 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
865 		if (leading_zeros) {
866 			if (digits < 3)
867 				*p++ = '0';
868 			if (digits < 2)
869 				*p++ = '0';
870 		}
871 		/* reverse the digits in the quad */
872 		while (digits--)
873 			*p++ = temp[digits];
874 		if (i < 3)
875 			*p++ = '.';
876 		index += step;
877 	}
878 	*p = '\0';
879 
880 	return p;
881 }
882 
883 static noinline_for_stack
884 char *ip6_compressed_string(char *p, const char *addr)
885 {
886 	int i, j, range;
887 	unsigned char zerolength[8];
888 	int longest = 1;
889 	int colonpos = -1;
890 	u16 word;
891 	u8 hi, lo;
892 	bool needcolon = false;
893 	bool useIPv4;
894 	struct in6_addr in6;
895 
896 	memcpy(&in6, addr, sizeof(struct in6_addr));
897 
898 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
899 
900 	memset(zerolength, 0, sizeof(zerolength));
901 
902 	if (useIPv4)
903 		range = 6;
904 	else
905 		range = 8;
906 
907 	/* find position of longest 0 run */
908 	for (i = 0; i < range; i++) {
909 		for (j = i; j < range; j++) {
910 			if (in6.s6_addr16[j] != 0)
911 				break;
912 			zerolength[i]++;
913 		}
914 	}
915 	for (i = 0; i < range; i++) {
916 		if (zerolength[i] > longest) {
917 			longest = zerolength[i];
918 			colonpos = i;
919 		}
920 	}
921 	if (longest == 1)		/* don't compress a single 0 */
922 		colonpos = -1;
923 
924 	/* emit address */
925 	for (i = 0; i < range; i++) {
926 		if (i == colonpos) {
927 			if (needcolon || i == 0)
928 				*p++ = ':';
929 			*p++ = ':';
930 			needcolon = false;
931 			i += longest - 1;
932 			continue;
933 		}
934 		if (needcolon) {
935 			*p++ = ':';
936 			needcolon = false;
937 		}
938 		/* hex u16 without leading 0s */
939 		word = ntohs(in6.s6_addr16[i]);
940 		hi = word >> 8;
941 		lo = word & 0xff;
942 		if (hi) {
943 			if (hi > 0x0f)
944 				p = hex_byte_pack(p, hi);
945 			else
946 				*p++ = hex_asc_lo(hi);
947 			p = hex_byte_pack(p, lo);
948 		}
949 		else if (lo > 0x0f)
950 			p = hex_byte_pack(p, lo);
951 		else
952 			*p++ = hex_asc_lo(lo);
953 		needcolon = true;
954 	}
955 
956 	if (useIPv4) {
957 		if (needcolon)
958 			*p++ = ':';
959 		p = ip4_string(p, &in6.s6_addr[12], "I4");
960 	}
961 	*p = '\0';
962 
963 	return p;
964 }
965 
966 static noinline_for_stack
967 char *ip6_string(char *p, const char *addr, const char *fmt)
968 {
969 	int i;
970 
971 	for (i = 0; i < 8; i++) {
972 		p = hex_byte_pack(p, *addr++);
973 		p = hex_byte_pack(p, *addr++);
974 		if (fmt[0] == 'I' && i != 7)
975 			*p++ = ':';
976 	}
977 	*p = '\0';
978 
979 	return p;
980 }
981 
982 static noinline_for_stack
983 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
984 		      struct printf_spec spec, const char *fmt)
985 {
986 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
987 
988 	if (fmt[0] == 'I' && fmt[2] == 'c')
989 		ip6_compressed_string(ip6_addr, addr);
990 	else
991 		ip6_string(ip6_addr, addr, fmt);
992 
993 	return string(buf, end, ip6_addr, spec);
994 }
995 
996 static noinline_for_stack
997 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
998 		      struct printf_spec spec, const char *fmt)
999 {
1000 	char ip4_addr[sizeof("255.255.255.255")];
1001 
1002 	ip4_string(ip4_addr, addr, fmt);
1003 
1004 	return string(buf, end, ip4_addr, spec);
1005 }
1006 
1007 static noinline_for_stack
1008 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1009 			 struct printf_spec spec, const char *fmt)
1010 {
1011 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1012 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1013 		      sizeof(":12345") + sizeof("/123456789") +
1014 		      sizeof("%1234567890")];
1015 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1016 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1017 	char fmt6[2] = { fmt[0], '6' };
1018 	u8 off = 0;
1019 
1020 	fmt++;
1021 	while (isalpha(*++fmt)) {
1022 		switch (*fmt) {
1023 		case 'p':
1024 			have_p = true;
1025 			break;
1026 		case 'f':
1027 			have_f = true;
1028 			break;
1029 		case 's':
1030 			have_s = true;
1031 			break;
1032 		case 'c':
1033 			have_c = true;
1034 			break;
1035 		}
1036 	}
1037 
1038 	if (have_p || have_s || have_f) {
1039 		*p = '[';
1040 		off = 1;
1041 	}
1042 
1043 	if (fmt6[0] == 'I' && have_c)
1044 		p = ip6_compressed_string(ip6_addr + off, addr);
1045 	else
1046 		p = ip6_string(ip6_addr + off, addr, fmt6);
1047 
1048 	if (have_p || have_s || have_f)
1049 		*p++ = ']';
1050 
1051 	if (have_p) {
1052 		*p++ = ':';
1053 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1054 	}
1055 	if (have_f) {
1056 		*p++ = '/';
1057 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1058 					  IPV6_FLOWINFO_MASK), spec);
1059 	}
1060 	if (have_s) {
1061 		*p++ = '%';
1062 		p = number(p, pend, sa->sin6_scope_id, spec);
1063 	}
1064 	*p = '\0';
1065 
1066 	return string(buf, end, ip6_addr, spec);
1067 }
1068 
1069 static noinline_for_stack
1070 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1071 			 struct printf_spec spec, const char *fmt)
1072 {
1073 	bool have_p = false;
1074 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1075 	char *pend = ip4_addr + sizeof(ip4_addr);
1076 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1077 	char fmt4[3] = { fmt[0], '4', 0 };
1078 
1079 	fmt++;
1080 	while (isalpha(*++fmt)) {
1081 		switch (*fmt) {
1082 		case 'p':
1083 			have_p = true;
1084 			break;
1085 		case 'h':
1086 		case 'l':
1087 		case 'n':
1088 		case 'b':
1089 			fmt4[2] = *fmt;
1090 			break;
1091 		}
1092 	}
1093 
1094 	p = ip4_string(ip4_addr, addr, fmt4);
1095 	if (have_p) {
1096 		*p++ = ':';
1097 		p = number(p, pend, ntohs(sa->sin_port), spec);
1098 	}
1099 	*p = '\0';
1100 
1101 	return string(buf, end, ip4_addr, spec);
1102 }
1103 
1104 static noinline_for_stack
1105 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1106 		     const char *fmt)
1107 {
1108 	bool found = true;
1109 	int count = 1;
1110 	unsigned int flags = 0;
1111 	int len;
1112 
1113 	if (spec.field_width == 0)
1114 		return buf;				/* nothing to print */
1115 
1116 	if (ZERO_OR_NULL_PTR(addr))
1117 		return string(buf, end, NULL, spec);	/* NULL pointer */
1118 
1119 
1120 	do {
1121 		switch (fmt[count++]) {
1122 		case 'a':
1123 			flags |= ESCAPE_ANY;
1124 			break;
1125 		case 'c':
1126 			flags |= ESCAPE_SPECIAL;
1127 			break;
1128 		case 'h':
1129 			flags |= ESCAPE_HEX;
1130 			break;
1131 		case 'n':
1132 			flags |= ESCAPE_NULL;
1133 			break;
1134 		case 'o':
1135 			flags |= ESCAPE_OCTAL;
1136 			break;
1137 		case 'p':
1138 			flags |= ESCAPE_NP;
1139 			break;
1140 		case 's':
1141 			flags |= ESCAPE_SPACE;
1142 			break;
1143 		default:
1144 			found = false;
1145 			break;
1146 		}
1147 	} while (found);
1148 
1149 	if (!flags)
1150 		flags = ESCAPE_ANY_NP;
1151 
1152 	len = spec.field_width < 0 ? 1 : spec.field_width;
1153 
1154 	/* Ignore the error. We print as many characters as we can */
1155 	string_escape_mem(addr, len, &buf, end - buf, flags, NULL);
1156 
1157 	return buf;
1158 }
1159 
1160 static noinline_for_stack
1161 char *uuid_string(char *buf, char *end, const u8 *addr,
1162 		  struct printf_spec spec, const char *fmt)
1163 {
1164 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1165 	char *p = uuid;
1166 	int i;
1167 	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1168 	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1169 	const u8 *index = be;
1170 	bool uc = false;
1171 
1172 	switch (*(++fmt)) {
1173 	case 'L':
1174 		uc = true;		/* fall-through */
1175 	case 'l':
1176 		index = le;
1177 		break;
1178 	case 'B':
1179 		uc = true;
1180 		break;
1181 	}
1182 
1183 	for (i = 0; i < 16; i++) {
1184 		p = hex_byte_pack(p, addr[index[i]]);
1185 		switch (i) {
1186 		case 3:
1187 		case 5:
1188 		case 7:
1189 		case 9:
1190 			*p++ = '-';
1191 			break;
1192 		}
1193 	}
1194 
1195 	*p = 0;
1196 
1197 	if (uc) {
1198 		p = uuid;
1199 		do {
1200 			*p = toupper(*p);
1201 		} while (*(++p));
1202 	}
1203 
1204 	return string(buf, end, uuid, spec);
1205 }
1206 
1207 static
1208 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1209 		      struct printf_spec spec)
1210 {
1211 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1212 	if (spec.field_width == -1)
1213 		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1214 	spec.base = 16;
1215 
1216 	return number(buf, end, *(const netdev_features_t *)addr, spec);
1217 }
1218 
1219 static noinline_for_stack
1220 char *address_val(char *buf, char *end, const void *addr,
1221 		  struct printf_spec spec, const char *fmt)
1222 {
1223 	unsigned long long num;
1224 
1225 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1226 	spec.base = 16;
1227 
1228 	switch (fmt[1]) {
1229 	case 'd':
1230 		num = *(const dma_addr_t *)addr;
1231 		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1232 		break;
1233 	case 'p':
1234 	default:
1235 		num = *(const phys_addr_t *)addr;
1236 		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1237 		break;
1238 	}
1239 
1240 	return number(buf, end, num, spec);
1241 }
1242 
1243 int kptr_restrict __read_mostly;
1244 
1245 /*
1246  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1247  * by an extra set of alphanumeric characters that are extended format
1248  * specifiers.
1249  *
1250  * Right now we handle:
1251  *
1252  * - 'F' For symbolic function descriptor pointers with offset
1253  * - 'f' For simple symbolic function names without offset
1254  * - 'S' For symbolic direct pointers with offset
1255  * - 's' For symbolic direct pointers without offset
1256  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1257  * - 'B' For backtraced symbolic direct pointers with offset
1258  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1259  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1260  * - 'M' For a 6-byte MAC address, it prints the address in the
1261  *       usual colon-separated hex notation
1262  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1263  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1264  *       with a dash-separated hex notation
1265  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1266  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1267  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1268  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1269  *       [S][pfs]
1270  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1271  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1272  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1273  *       IPv6 omits the colons (01020304...0f)
1274  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1275  *       [S][pfs]
1276  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1277  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1278  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1279  * - 'I[6S]c' for IPv6 addresses printed as specified by
1280  *       http://tools.ietf.org/html/rfc5952
1281  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1282  *                of the following flags (see string_escape_mem() for the
1283  *                details):
1284  *                  a - ESCAPE_ANY
1285  *                  c - ESCAPE_SPECIAL
1286  *                  h - ESCAPE_HEX
1287  *                  n - ESCAPE_NULL
1288  *                  o - ESCAPE_OCTAL
1289  *                  p - ESCAPE_NP
1290  *                  s - ESCAPE_SPACE
1291  *                By default ESCAPE_ANY_NP is used.
1292  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1293  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1294  *       Options for %pU are:
1295  *         b big endian lower case hex (default)
1296  *         B big endian UPPER case hex
1297  *         l little endian lower case hex
1298  *         L little endian UPPER case hex
1299  *           big endian output byte order is:
1300  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1301  *           little endian output byte order is:
1302  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1303  * - 'V' For a struct va_format which contains a format string * and va_list *,
1304  *       call vsnprintf(->format, *->va_list).
1305  *       Implements a "recursive vsnprintf".
1306  *       Do not use this feature without some mechanism to verify the
1307  *       correctness of the format string and va_list arguments.
1308  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1309  * - 'NF' For a netdev_features_t
1310  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1311  *            a certain separator (' ' by default):
1312  *              C colon
1313  *              D dash
1314  *              N no separator
1315  *            The maximum supported length is 64 bytes of the input. Consider
1316  *            to use print_hex_dump() for the larger input.
1317  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1318  *           (default assumed to be phys_addr_t, passed by reference)
1319  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1320  * - 'D[234]' Same as 'd' but for a struct file
1321  *
1322  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1323  * function pointers are really function descriptors, which contain a
1324  * pointer to the real address.
1325  */
1326 static noinline_for_stack
1327 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1328 	      struct printf_spec spec)
1329 {
1330 	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1331 
1332 	if (!ptr && *fmt != 'K') {
1333 		/*
1334 		 * Print (null) with the same width as a pointer so it makes
1335 		 * tabular output look nice.
1336 		 */
1337 		if (spec.field_width == -1)
1338 			spec.field_width = default_width;
1339 		return string(buf, end, "(null)", spec);
1340 	}
1341 
1342 	switch (*fmt) {
1343 	case 'F':
1344 	case 'f':
1345 		ptr = dereference_function_descriptor(ptr);
1346 		/* Fallthrough */
1347 	case 'S':
1348 	case 's':
1349 	case 'B':
1350 		return symbol_string(buf, end, ptr, spec, fmt);
1351 	case 'R':
1352 	case 'r':
1353 		return resource_string(buf, end, ptr, spec, fmt);
1354 	case 'h':
1355 		return hex_string(buf, end, ptr, spec, fmt);
1356 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
1357 	case 'm':			/* Contiguous: 000102030405 */
1358 					/* [mM]F (FDDI) */
1359 					/* [mM]R (Reverse order; Bluetooth) */
1360 		return mac_address_string(buf, end, ptr, spec, fmt);
1361 	case 'I':			/* Formatted IP supported
1362 					 * 4:	1.2.3.4
1363 					 * 6:	0001:0203:...:0708
1364 					 * 6c:	1::708 or 1::1.2.3.4
1365 					 */
1366 	case 'i':			/* Contiguous:
1367 					 * 4:	001.002.003.004
1368 					 * 6:   000102...0f
1369 					 */
1370 		switch (fmt[1]) {
1371 		case '6':
1372 			return ip6_addr_string(buf, end, ptr, spec, fmt);
1373 		case '4':
1374 			return ip4_addr_string(buf, end, ptr, spec, fmt);
1375 		case 'S': {
1376 			const union {
1377 				struct sockaddr		raw;
1378 				struct sockaddr_in	v4;
1379 				struct sockaddr_in6	v6;
1380 			} *sa = ptr;
1381 
1382 			switch (sa->raw.sa_family) {
1383 			case AF_INET:
1384 				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1385 			case AF_INET6:
1386 				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1387 			default:
1388 				return string(buf, end, "(invalid address)", spec);
1389 			}}
1390 		}
1391 		break;
1392 	case 'E':
1393 		return escaped_string(buf, end, ptr, spec, fmt);
1394 	case 'U':
1395 		return uuid_string(buf, end, ptr, spec, fmt);
1396 	case 'V':
1397 		{
1398 			va_list va;
1399 
1400 			va_copy(va, *((struct va_format *)ptr)->va);
1401 			buf += vsnprintf(buf, end > buf ? end - buf : 0,
1402 					 ((struct va_format *)ptr)->fmt, va);
1403 			va_end(va);
1404 			return buf;
1405 		}
1406 	case 'K':
1407 		/*
1408 		 * %pK cannot be used in IRQ context because its test
1409 		 * for CAP_SYSLOG would be meaningless.
1410 		 */
1411 		if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1412 				      in_nmi())) {
1413 			if (spec.field_width == -1)
1414 				spec.field_width = default_width;
1415 			return string(buf, end, "pK-error", spec);
1416 		}
1417 
1418 		switch (kptr_restrict) {
1419 		case 0:
1420 			/* Always print %pK values */
1421 			break;
1422 		case 1: {
1423 			/*
1424 			 * Only print the real pointer value if the current
1425 			 * process has CAP_SYSLOG and is running with the
1426 			 * same credentials it started with. This is because
1427 			 * access to files is checked at open() time, but %pK
1428 			 * checks permission at read() time. We don't want to
1429 			 * leak pointer values if a binary opens a file using
1430 			 * %pK and then elevates privileges before reading it.
1431 			 */
1432 			const struct cred *cred = current_cred();
1433 
1434 			if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1435 			    !uid_eq(cred->euid, cred->uid) ||
1436 			    !gid_eq(cred->egid, cred->gid))
1437 				ptr = NULL;
1438 			break;
1439 		}
1440 		case 2:
1441 		default:
1442 			/* Always print 0's for %pK */
1443 			ptr = NULL;
1444 			break;
1445 		}
1446 		break;
1447 
1448 	case 'N':
1449 		switch (fmt[1]) {
1450 		case 'F':
1451 			return netdev_feature_string(buf, end, ptr, spec);
1452 		}
1453 		break;
1454 	case 'a':
1455 		return address_val(buf, end, ptr, spec, fmt);
1456 	case 'd':
1457 		return dentry_name(buf, end, ptr, spec, fmt);
1458 	case 'D':
1459 		return dentry_name(buf, end,
1460 				   ((const struct file *)ptr)->f_path.dentry,
1461 				   spec, fmt);
1462 	}
1463 	spec.flags |= SMALL;
1464 	if (spec.field_width == -1) {
1465 		spec.field_width = default_width;
1466 		spec.flags |= ZEROPAD;
1467 	}
1468 	spec.base = 16;
1469 
1470 	return number(buf, end, (unsigned long) ptr, spec);
1471 }
1472 
1473 /*
1474  * Helper function to decode printf style format.
1475  * Each call decode a token from the format and return the
1476  * number of characters read (or likely the delta where it wants
1477  * to go on the next call).
1478  * The decoded token is returned through the parameters
1479  *
1480  * 'h', 'l', or 'L' for integer fields
1481  * 'z' support added 23/7/1999 S.H.
1482  * 'z' changed to 'Z' --davidm 1/25/99
1483  * 't' added for ptrdiff_t
1484  *
1485  * @fmt: the format string
1486  * @type of the token returned
1487  * @flags: various flags such as +, -, # tokens..
1488  * @field_width: overwritten width
1489  * @base: base of the number (octal, hex, ...)
1490  * @precision: precision of a number
1491  * @qualifier: qualifier of a number (long, size_t, ...)
1492  */
1493 static noinline_for_stack
1494 int format_decode(const char *fmt, struct printf_spec *spec)
1495 {
1496 	const char *start = fmt;
1497 
1498 	/* we finished early by reading the field width */
1499 	if (spec->type == FORMAT_TYPE_WIDTH) {
1500 		if (spec->field_width < 0) {
1501 			spec->field_width = -spec->field_width;
1502 			spec->flags |= LEFT;
1503 		}
1504 		spec->type = FORMAT_TYPE_NONE;
1505 		goto precision;
1506 	}
1507 
1508 	/* we finished early by reading the precision */
1509 	if (spec->type == FORMAT_TYPE_PRECISION) {
1510 		if (spec->precision < 0)
1511 			spec->precision = 0;
1512 
1513 		spec->type = FORMAT_TYPE_NONE;
1514 		goto qualifier;
1515 	}
1516 
1517 	/* By default */
1518 	spec->type = FORMAT_TYPE_NONE;
1519 
1520 	for (; *fmt ; ++fmt) {
1521 		if (*fmt == '%')
1522 			break;
1523 	}
1524 
1525 	/* Return the current non-format string */
1526 	if (fmt != start || !*fmt)
1527 		return fmt - start;
1528 
1529 	/* Process flags */
1530 	spec->flags = 0;
1531 
1532 	while (1) { /* this also skips first '%' */
1533 		bool found = true;
1534 
1535 		++fmt;
1536 
1537 		switch (*fmt) {
1538 		case '-': spec->flags |= LEFT;    break;
1539 		case '+': spec->flags |= PLUS;    break;
1540 		case ' ': spec->flags |= SPACE;   break;
1541 		case '#': spec->flags |= SPECIAL; break;
1542 		case '0': spec->flags |= ZEROPAD; break;
1543 		default:  found = false;
1544 		}
1545 
1546 		if (!found)
1547 			break;
1548 	}
1549 
1550 	/* get field width */
1551 	spec->field_width = -1;
1552 
1553 	if (isdigit(*fmt))
1554 		spec->field_width = skip_atoi(&fmt);
1555 	else if (*fmt == '*') {
1556 		/* it's the next argument */
1557 		spec->type = FORMAT_TYPE_WIDTH;
1558 		return ++fmt - start;
1559 	}
1560 
1561 precision:
1562 	/* get the precision */
1563 	spec->precision = -1;
1564 	if (*fmt == '.') {
1565 		++fmt;
1566 		if (isdigit(*fmt)) {
1567 			spec->precision = skip_atoi(&fmt);
1568 			if (spec->precision < 0)
1569 				spec->precision = 0;
1570 		} else if (*fmt == '*') {
1571 			/* it's the next argument */
1572 			spec->type = FORMAT_TYPE_PRECISION;
1573 			return ++fmt - start;
1574 		}
1575 	}
1576 
1577 qualifier:
1578 	/* get the conversion qualifier */
1579 	spec->qualifier = -1;
1580 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1581 	    _tolower(*fmt) == 'z' || *fmt == 't') {
1582 		spec->qualifier = *fmt++;
1583 		if (unlikely(spec->qualifier == *fmt)) {
1584 			if (spec->qualifier == 'l') {
1585 				spec->qualifier = 'L';
1586 				++fmt;
1587 			} else if (spec->qualifier == 'h') {
1588 				spec->qualifier = 'H';
1589 				++fmt;
1590 			}
1591 		}
1592 	}
1593 
1594 	/* default base */
1595 	spec->base = 10;
1596 	switch (*fmt) {
1597 	case 'c':
1598 		spec->type = FORMAT_TYPE_CHAR;
1599 		return ++fmt - start;
1600 
1601 	case 's':
1602 		spec->type = FORMAT_TYPE_STR;
1603 		return ++fmt - start;
1604 
1605 	case 'p':
1606 		spec->type = FORMAT_TYPE_PTR;
1607 		return fmt - start;
1608 		/* skip alnum */
1609 
1610 	case '%':
1611 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1612 		return ++fmt - start;
1613 
1614 	/* integer number formats - set up the flags and "break" */
1615 	case 'o':
1616 		spec->base = 8;
1617 		break;
1618 
1619 	case 'x':
1620 		spec->flags |= SMALL;
1621 
1622 	case 'X':
1623 		spec->base = 16;
1624 		break;
1625 
1626 	case 'd':
1627 	case 'i':
1628 		spec->flags |= SIGN;
1629 	case 'u':
1630 		break;
1631 
1632 	case 'n':
1633 		/*
1634 		 * Since %n poses a greater security risk than utility, treat
1635 		 * it as an invalid format specifier. Warn about its use so
1636 		 * that new instances don't get added.
1637 		 */
1638 		WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1639 		/* Fall-through */
1640 
1641 	default:
1642 		spec->type = FORMAT_TYPE_INVALID;
1643 		return fmt - start;
1644 	}
1645 
1646 	if (spec->qualifier == 'L')
1647 		spec->type = FORMAT_TYPE_LONG_LONG;
1648 	else if (spec->qualifier == 'l') {
1649 		if (spec->flags & SIGN)
1650 			spec->type = FORMAT_TYPE_LONG;
1651 		else
1652 			spec->type = FORMAT_TYPE_ULONG;
1653 	} else if (_tolower(spec->qualifier) == 'z') {
1654 		spec->type = FORMAT_TYPE_SIZE_T;
1655 	} else if (spec->qualifier == 't') {
1656 		spec->type = FORMAT_TYPE_PTRDIFF;
1657 	} else if (spec->qualifier == 'H') {
1658 		if (spec->flags & SIGN)
1659 			spec->type = FORMAT_TYPE_BYTE;
1660 		else
1661 			spec->type = FORMAT_TYPE_UBYTE;
1662 	} else if (spec->qualifier == 'h') {
1663 		if (spec->flags & SIGN)
1664 			spec->type = FORMAT_TYPE_SHORT;
1665 		else
1666 			spec->type = FORMAT_TYPE_USHORT;
1667 	} else {
1668 		if (spec->flags & SIGN)
1669 			spec->type = FORMAT_TYPE_INT;
1670 		else
1671 			spec->type = FORMAT_TYPE_UINT;
1672 	}
1673 
1674 	return ++fmt - start;
1675 }
1676 
1677 /**
1678  * vsnprintf - Format a string and place it in a buffer
1679  * @buf: The buffer to place the result into
1680  * @size: The size of the buffer, including the trailing null space
1681  * @fmt: The format string to use
1682  * @args: Arguments for the format string
1683  *
1684  * This function follows C99 vsnprintf, but has some extensions:
1685  * %pS output the name of a text symbol with offset
1686  * %ps output the name of a text symbol without offset
1687  * %pF output the name of a function pointer with its offset
1688  * %pf output the name of a function pointer without its offset
1689  * %pB output the name of a backtrace symbol with its offset
1690  * %pR output the address range in a struct resource with decoded flags
1691  * %pr output the address range in a struct resource with raw flags
1692  * %pM output a 6-byte MAC address with colons
1693  * %pMR output a 6-byte MAC address with colons in reversed order
1694  * %pMF output a 6-byte MAC address with dashes
1695  * %pm output a 6-byte MAC address without colons
1696  * %pmR output a 6-byte MAC address without colons in reversed order
1697  * %pI4 print an IPv4 address without leading zeros
1698  * %pi4 print an IPv4 address with leading zeros
1699  * %pI6 print an IPv6 address with colons
1700  * %pi6 print an IPv6 address without colons
1701  * %pI6c print an IPv6 address as specified by RFC 5952
1702  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1703  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1704  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1705  *   case.
1706  * %*pE[achnops] print an escaped buffer
1707  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1708  *           bytes of the input)
1709  * %n is ignored
1710  *
1711  * ** Please update Documentation/printk-formats.txt when making changes **
1712  *
1713  * The return value is the number of characters which would
1714  * be generated for the given input, excluding the trailing
1715  * '\0', as per ISO C99. If you want to have the exact
1716  * number of characters written into @buf as return value
1717  * (not including the trailing '\0'), use vscnprintf(). If the
1718  * return is greater than or equal to @size, the resulting
1719  * string is truncated.
1720  *
1721  * If you're not already dealing with a va_list consider using snprintf().
1722  */
1723 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1724 {
1725 	unsigned long long num;
1726 	char *str, *end;
1727 	struct printf_spec spec = {0};
1728 
1729 	/* Reject out-of-range values early.  Large positive sizes are
1730 	   used for unknown buffer sizes. */
1731 	if (WARN_ON_ONCE((int) size < 0))
1732 		return 0;
1733 
1734 	str = buf;
1735 	end = buf + size;
1736 
1737 	/* Make sure end is always >= buf */
1738 	if (end < buf) {
1739 		end = ((void *)-1);
1740 		size = end - buf;
1741 	}
1742 
1743 	while (*fmt) {
1744 		const char *old_fmt = fmt;
1745 		int read = format_decode(fmt, &spec);
1746 
1747 		fmt += read;
1748 
1749 		switch (spec.type) {
1750 		case FORMAT_TYPE_NONE: {
1751 			int copy = read;
1752 			if (str < end) {
1753 				if (copy > end - str)
1754 					copy = end - str;
1755 				memcpy(str, old_fmt, copy);
1756 			}
1757 			str += read;
1758 			break;
1759 		}
1760 
1761 		case FORMAT_TYPE_WIDTH:
1762 			spec.field_width = va_arg(args, int);
1763 			break;
1764 
1765 		case FORMAT_TYPE_PRECISION:
1766 			spec.precision = va_arg(args, int);
1767 			break;
1768 
1769 		case FORMAT_TYPE_CHAR: {
1770 			char c;
1771 
1772 			if (!(spec.flags & LEFT)) {
1773 				while (--spec.field_width > 0) {
1774 					if (str < end)
1775 						*str = ' ';
1776 					++str;
1777 
1778 				}
1779 			}
1780 			c = (unsigned char) va_arg(args, int);
1781 			if (str < end)
1782 				*str = c;
1783 			++str;
1784 			while (--spec.field_width > 0) {
1785 				if (str < end)
1786 					*str = ' ';
1787 				++str;
1788 			}
1789 			break;
1790 		}
1791 
1792 		case FORMAT_TYPE_STR:
1793 			str = string(str, end, va_arg(args, char *), spec);
1794 			break;
1795 
1796 		case FORMAT_TYPE_PTR:
1797 			str = pointer(fmt+1, str, end, va_arg(args, void *),
1798 				      spec);
1799 			while (isalnum(*fmt))
1800 				fmt++;
1801 			break;
1802 
1803 		case FORMAT_TYPE_PERCENT_CHAR:
1804 			if (str < end)
1805 				*str = '%';
1806 			++str;
1807 			break;
1808 
1809 		case FORMAT_TYPE_INVALID:
1810 			if (str < end)
1811 				*str = '%';
1812 			++str;
1813 			break;
1814 
1815 		default:
1816 			switch (spec.type) {
1817 			case FORMAT_TYPE_LONG_LONG:
1818 				num = va_arg(args, long long);
1819 				break;
1820 			case FORMAT_TYPE_ULONG:
1821 				num = va_arg(args, unsigned long);
1822 				break;
1823 			case FORMAT_TYPE_LONG:
1824 				num = va_arg(args, long);
1825 				break;
1826 			case FORMAT_TYPE_SIZE_T:
1827 				if (spec.flags & SIGN)
1828 					num = va_arg(args, ssize_t);
1829 				else
1830 					num = va_arg(args, size_t);
1831 				break;
1832 			case FORMAT_TYPE_PTRDIFF:
1833 				num = va_arg(args, ptrdiff_t);
1834 				break;
1835 			case FORMAT_TYPE_UBYTE:
1836 				num = (unsigned char) va_arg(args, int);
1837 				break;
1838 			case FORMAT_TYPE_BYTE:
1839 				num = (signed char) va_arg(args, int);
1840 				break;
1841 			case FORMAT_TYPE_USHORT:
1842 				num = (unsigned short) va_arg(args, int);
1843 				break;
1844 			case FORMAT_TYPE_SHORT:
1845 				num = (short) va_arg(args, int);
1846 				break;
1847 			case FORMAT_TYPE_INT:
1848 				num = (int) va_arg(args, int);
1849 				break;
1850 			default:
1851 				num = va_arg(args, unsigned int);
1852 			}
1853 
1854 			str = number(str, end, num, spec);
1855 		}
1856 	}
1857 
1858 	if (size > 0) {
1859 		if (str < end)
1860 			*str = '\0';
1861 		else
1862 			end[-1] = '\0';
1863 	}
1864 
1865 	/* the trailing null byte doesn't count towards the total */
1866 	return str-buf;
1867 
1868 }
1869 EXPORT_SYMBOL(vsnprintf);
1870 
1871 /**
1872  * vscnprintf - Format a string and place it in a buffer
1873  * @buf: The buffer to place the result into
1874  * @size: The size of the buffer, including the trailing null space
1875  * @fmt: The format string to use
1876  * @args: Arguments for the format string
1877  *
1878  * The return value is the number of characters which have been written into
1879  * the @buf not including the trailing '\0'. If @size is == 0 the function
1880  * returns 0.
1881  *
1882  * If you're not already dealing with a va_list consider using scnprintf().
1883  *
1884  * See the vsnprintf() documentation for format string extensions over C99.
1885  */
1886 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1887 {
1888 	int i;
1889 
1890 	i = vsnprintf(buf, size, fmt, args);
1891 
1892 	if (likely(i < size))
1893 		return i;
1894 	if (size != 0)
1895 		return size - 1;
1896 	return 0;
1897 }
1898 EXPORT_SYMBOL(vscnprintf);
1899 
1900 /**
1901  * snprintf - Format a string and place it in a buffer
1902  * @buf: The buffer to place the result into
1903  * @size: The size of the buffer, including the trailing null space
1904  * @fmt: The format string to use
1905  * @...: Arguments for the format string
1906  *
1907  * The return value is the number of characters which would be
1908  * generated for the given input, excluding the trailing null,
1909  * as per ISO C99.  If the return is greater than or equal to
1910  * @size, the resulting string is truncated.
1911  *
1912  * See the vsnprintf() documentation for format string extensions over C99.
1913  */
1914 int snprintf(char *buf, size_t size, const char *fmt, ...)
1915 {
1916 	va_list args;
1917 	int i;
1918 
1919 	va_start(args, fmt);
1920 	i = vsnprintf(buf, size, fmt, args);
1921 	va_end(args);
1922 
1923 	return i;
1924 }
1925 EXPORT_SYMBOL(snprintf);
1926 
1927 /**
1928  * scnprintf - Format a string and place it in a buffer
1929  * @buf: The buffer to place the result into
1930  * @size: The size of the buffer, including the trailing null space
1931  * @fmt: The format string to use
1932  * @...: Arguments for the format string
1933  *
1934  * The return value is the number of characters written into @buf not including
1935  * the trailing '\0'. If @size is == 0 the function returns 0.
1936  */
1937 
1938 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1939 {
1940 	va_list args;
1941 	int i;
1942 
1943 	va_start(args, fmt);
1944 	i = vscnprintf(buf, size, fmt, args);
1945 	va_end(args);
1946 
1947 	return i;
1948 }
1949 EXPORT_SYMBOL(scnprintf);
1950 
1951 /**
1952  * vsprintf - Format a string and place it in a buffer
1953  * @buf: The buffer to place the result into
1954  * @fmt: The format string to use
1955  * @args: Arguments for the format string
1956  *
1957  * The function returns the number of characters written
1958  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1959  * buffer overflows.
1960  *
1961  * If you're not already dealing with a va_list consider using sprintf().
1962  *
1963  * See the vsnprintf() documentation for format string extensions over C99.
1964  */
1965 int vsprintf(char *buf, const char *fmt, va_list args)
1966 {
1967 	return vsnprintf(buf, INT_MAX, fmt, args);
1968 }
1969 EXPORT_SYMBOL(vsprintf);
1970 
1971 /**
1972  * sprintf - Format a string and place it in a buffer
1973  * @buf: The buffer to place the result into
1974  * @fmt: The format string to use
1975  * @...: Arguments for the format string
1976  *
1977  * The function returns the number of characters written
1978  * into @buf. Use snprintf() or scnprintf() in order to avoid
1979  * buffer overflows.
1980  *
1981  * See the vsnprintf() documentation for format string extensions over C99.
1982  */
1983 int sprintf(char *buf, const char *fmt, ...)
1984 {
1985 	va_list args;
1986 	int i;
1987 
1988 	va_start(args, fmt);
1989 	i = vsnprintf(buf, INT_MAX, fmt, args);
1990 	va_end(args);
1991 
1992 	return i;
1993 }
1994 EXPORT_SYMBOL(sprintf);
1995 
1996 #ifdef CONFIG_BINARY_PRINTF
1997 /*
1998  * bprintf service:
1999  * vbin_printf() - VA arguments to binary data
2000  * bstr_printf() - Binary data to text string
2001  */
2002 
2003 /**
2004  * vbin_printf - Parse a format string and place args' binary value in a buffer
2005  * @bin_buf: The buffer to place args' binary value
2006  * @size: The size of the buffer(by words(32bits), not characters)
2007  * @fmt: The format string to use
2008  * @args: Arguments for the format string
2009  *
2010  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2011  * is skipped.
2012  *
2013  * The return value is the number of words(32bits) which would be generated for
2014  * the given input.
2015  *
2016  * NOTE:
2017  * If the return value is greater than @size, the resulting bin_buf is NOT
2018  * valid for bstr_printf().
2019  */
2020 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2021 {
2022 	struct printf_spec spec = {0};
2023 	char *str, *end;
2024 
2025 	str = (char *)bin_buf;
2026 	end = (char *)(bin_buf + size);
2027 
2028 #define save_arg(type)							\
2029 do {									\
2030 	if (sizeof(type) == 8) {					\
2031 		unsigned long long value;				\
2032 		str = PTR_ALIGN(str, sizeof(u32));			\
2033 		value = va_arg(args, unsigned long long);		\
2034 		if (str + sizeof(type) <= end) {			\
2035 			*(u32 *)str = *(u32 *)&value;			\
2036 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
2037 		}							\
2038 	} else {							\
2039 		unsigned long value;					\
2040 		str = PTR_ALIGN(str, sizeof(type));			\
2041 		value = va_arg(args, int);				\
2042 		if (str + sizeof(type) <= end)				\
2043 			*(typeof(type) *)str = (type)value;		\
2044 	}								\
2045 	str += sizeof(type);						\
2046 } while (0)
2047 
2048 	while (*fmt) {
2049 		int read = format_decode(fmt, &spec);
2050 
2051 		fmt += read;
2052 
2053 		switch (spec.type) {
2054 		case FORMAT_TYPE_NONE:
2055 		case FORMAT_TYPE_INVALID:
2056 		case FORMAT_TYPE_PERCENT_CHAR:
2057 			break;
2058 
2059 		case FORMAT_TYPE_WIDTH:
2060 		case FORMAT_TYPE_PRECISION:
2061 			save_arg(int);
2062 			break;
2063 
2064 		case FORMAT_TYPE_CHAR:
2065 			save_arg(char);
2066 			break;
2067 
2068 		case FORMAT_TYPE_STR: {
2069 			const char *save_str = va_arg(args, char *);
2070 			size_t len;
2071 
2072 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2073 					|| (unsigned long)save_str < PAGE_SIZE)
2074 				save_str = "(null)";
2075 			len = strlen(save_str) + 1;
2076 			if (str + len < end)
2077 				memcpy(str, save_str, len);
2078 			str += len;
2079 			break;
2080 		}
2081 
2082 		case FORMAT_TYPE_PTR:
2083 			save_arg(void *);
2084 			/* skip all alphanumeric pointer suffixes */
2085 			while (isalnum(*fmt))
2086 				fmt++;
2087 			break;
2088 
2089 		default:
2090 			switch (spec.type) {
2091 
2092 			case FORMAT_TYPE_LONG_LONG:
2093 				save_arg(long long);
2094 				break;
2095 			case FORMAT_TYPE_ULONG:
2096 			case FORMAT_TYPE_LONG:
2097 				save_arg(unsigned long);
2098 				break;
2099 			case FORMAT_TYPE_SIZE_T:
2100 				save_arg(size_t);
2101 				break;
2102 			case FORMAT_TYPE_PTRDIFF:
2103 				save_arg(ptrdiff_t);
2104 				break;
2105 			case FORMAT_TYPE_UBYTE:
2106 			case FORMAT_TYPE_BYTE:
2107 				save_arg(char);
2108 				break;
2109 			case FORMAT_TYPE_USHORT:
2110 			case FORMAT_TYPE_SHORT:
2111 				save_arg(short);
2112 				break;
2113 			default:
2114 				save_arg(int);
2115 			}
2116 		}
2117 	}
2118 
2119 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2120 #undef save_arg
2121 }
2122 EXPORT_SYMBOL_GPL(vbin_printf);
2123 
2124 /**
2125  * bstr_printf - Format a string from binary arguments and place it in a buffer
2126  * @buf: The buffer to place the result into
2127  * @size: The size of the buffer, including the trailing null space
2128  * @fmt: The format string to use
2129  * @bin_buf: Binary arguments for the format string
2130  *
2131  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2132  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2133  * a binary buffer that generated by vbin_printf.
2134  *
2135  * The format follows C99 vsnprintf, but has some extensions:
2136  *  see vsnprintf comment for details.
2137  *
2138  * The return value is the number of characters which would
2139  * be generated for the given input, excluding the trailing
2140  * '\0', as per ISO C99. If you want to have the exact
2141  * number of characters written into @buf as return value
2142  * (not including the trailing '\0'), use vscnprintf(). If the
2143  * return is greater than or equal to @size, the resulting
2144  * string is truncated.
2145  */
2146 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2147 {
2148 	struct printf_spec spec = {0};
2149 	char *str, *end;
2150 	const char *args = (const char *)bin_buf;
2151 
2152 	if (WARN_ON_ONCE((int) size < 0))
2153 		return 0;
2154 
2155 	str = buf;
2156 	end = buf + size;
2157 
2158 #define get_arg(type)							\
2159 ({									\
2160 	typeof(type) value;						\
2161 	if (sizeof(type) == 8) {					\
2162 		args = PTR_ALIGN(args, sizeof(u32));			\
2163 		*(u32 *)&value = *(u32 *)args;				\
2164 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2165 	} else {							\
2166 		args = PTR_ALIGN(args, sizeof(type));			\
2167 		value = *(typeof(type) *)args;				\
2168 	}								\
2169 	args += sizeof(type);						\
2170 	value;								\
2171 })
2172 
2173 	/* Make sure end is always >= buf */
2174 	if (end < buf) {
2175 		end = ((void *)-1);
2176 		size = end - buf;
2177 	}
2178 
2179 	while (*fmt) {
2180 		const char *old_fmt = fmt;
2181 		int read = format_decode(fmt, &spec);
2182 
2183 		fmt += read;
2184 
2185 		switch (spec.type) {
2186 		case FORMAT_TYPE_NONE: {
2187 			int copy = read;
2188 			if (str < end) {
2189 				if (copy > end - str)
2190 					copy = end - str;
2191 				memcpy(str, old_fmt, copy);
2192 			}
2193 			str += read;
2194 			break;
2195 		}
2196 
2197 		case FORMAT_TYPE_WIDTH:
2198 			spec.field_width = get_arg(int);
2199 			break;
2200 
2201 		case FORMAT_TYPE_PRECISION:
2202 			spec.precision = get_arg(int);
2203 			break;
2204 
2205 		case FORMAT_TYPE_CHAR: {
2206 			char c;
2207 
2208 			if (!(spec.flags & LEFT)) {
2209 				while (--spec.field_width > 0) {
2210 					if (str < end)
2211 						*str = ' ';
2212 					++str;
2213 				}
2214 			}
2215 			c = (unsigned char) get_arg(char);
2216 			if (str < end)
2217 				*str = c;
2218 			++str;
2219 			while (--spec.field_width > 0) {
2220 				if (str < end)
2221 					*str = ' ';
2222 				++str;
2223 			}
2224 			break;
2225 		}
2226 
2227 		case FORMAT_TYPE_STR: {
2228 			const char *str_arg = args;
2229 			args += strlen(str_arg) + 1;
2230 			str = string(str, end, (char *)str_arg, spec);
2231 			break;
2232 		}
2233 
2234 		case FORMAT_TYPE_PTR:
2235 			str = pointer(fmt+1, str, end, get_arg(void *), spec);
2236 			while (isalnum(*fmt))
2237 				fmt++;
2238 			break;
2239 
2240 		case FORMAT_TYPE_PERCENT_CHAR:
2241 		case FORMAT_TYPE_INVALID:
2242 			if (str < end)
2243 				*str = '%';
2244 			++str;
2245 			break;
2246 
2247 		default: {
2248 			unsigned long long num;
2249 
2250 			switch (spec.type) {
2251 
2252 			case FORMAT_TYPE_LONG_LONG:
2253 				num = get_arg(long long);
2254 				break;
2255 			case FORMAT_TYPE_ULONG:
2256 			case FORMAT_TYPE_LONG:
2257 				num = get_arg(unsigned long);
2258 				break;
2259 			case FORMAT_TYPE_SIZE_T:
2260 				num = get_arg(size_t);
2261 				break;
2262 			case FORMAT_TYPE_PTRDIFF:
2263 				num = get_arg(ptrdiff_t);
2264 				break;
2265 			case FORMAT_TYPE_UBYTE:
2266 				num = get_arg(unsigned char);
2267 				break;
2268 			case FORMAT_TYPE_BYTE:
2269 				num = get_arg(signed char);
2270 				break;
2271 			case FORMAT_TYPE_USHORT:
2272 				num = get_arg(unsigned short);
2273 				break;
2274 			case FORMAT_TYPE_SHORT:
2275 				num = get_arg(short);
2276 				break;
2277 			case FORMAT_TYPE_UINT:
2278 				num = get_arg(unsigned int);
2279 				break;
2280 			default:
2281 				num = get_arg(int);
2282 			}
2283 
2284 			str = number(str, end, num, spec);
2285 		} /* default: */
2286 		} /* switch(spec.type) */
2287 	} /* while(*fmt) */
2288 
2289 	if (size > 0) {
2290 		if (str < end)
2291 			*str = '\0';
2292 		else
2293 			end[-1] = '\0';
2294 	}
2295 
2296 #undef get_arg
2297 
2298 	/* the trailing null byte doesn't count towards the total */
2299 	return str - buf;
2300 }
2301 EXPORT_SYMBOL_GPL(bstr_printf);
2302 
2303 /**
2304  * bprintf - Parse a format string and place args' binary value in a buffer
2305  * @bin_buf: The buffer to place args' binary value
2306  * @size: The size of the buffer(by words(32bits), not characters)
2307  * @fmt: The format string to use
2308  * @...: Arguments for the format string
2309  *
2310  * The function returns the number of words(u32) written
2311  * into @bin_buf.
2312  */
2313 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2314 {
2315 	va_list args;
2316 	int ret;
2317 
2318 	va_start(args, fmt);
2319 	ret = vbin_printf(bin_buf, size, fmt, args);
2320 	va_end(args);
2321 
2322 	return ret;
2323 }
2324 EXPORT_SYMBOL_GPL(bprintf);
2325 
2326 #endif /* CONFIG_BINARY_PRINTF */
2327 
2328 /**
2329  * vsscanf - Unformat a buffer into a list of arguments
2330  * @buf:	input buffer
2331  * @fmt:	format of buffer
2332  * @args:	arguments
2333  */
2334 int vsscanf(const char *buf, const char *fmt, va_list args)
2335 {
2336 	const char *str = buf;
2337 	char *next;
2338 	char digit;
2339 	int num = 0;
2340 	u8 qualifier;
2341 	unsigned int base;
2342 	union {
2343 		long long s;
2344 		unsigned long long u;
2345 	} val;
2346 	s16 field_width;
2347 	bool is_sign;
2348 
2349 	while (*fmt) {
2350 		/* skip any white space in format */
2351 		/* white space in format matchs any amount of
2352 		 * white space, including none, in the input.
2353 		 */
2354 		if (isspace(*fmt)) {
2355 			fmt = skip_spaces(++fmt);
2356 			str = skip_spaces(str);
2357 		}
2358 
2359 		/* anything that is not a conversion must match exactly */
2360 		if (*fmt != '%' && *fmt) {
2361 			if (*fmt++ != *str++)
2362 				break;
2363 			continue;
2364 		}
2365 
2366 		if (!*fmt)
2367 			break;
2368 		++fmt;
2369 
2370 		/* skip this conversion.
2371 		 * advance both strings to next white space
2372 		 */
2373 		if (*fmt == '*') {
2374 			if (!*str)
2375 				break;
2376 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
2377 				fmt++;
2378 			while (!isspace(*str) && *str)
2379 				str++;
2380 			continue;
2381 		}
2382 
2383 		/* get field width */
2384 		field_width = -1;
2385 		if (isdigit(*fmt)) {
2386 			field_width = skip_atoi(&fmt);
2387 			if (field_width <= 0)
2388 				break;
2389 		}
2390 
2391 		/* get conversion qualifier */
2392 		qualifier = -1;
2393 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2394 		    _tolower(*fmt) == 'z') {
2395 			qualifier = *fmt++;
2396 			if (unlikely(qualifier == *fmt)) {
2397 				if (qualifier == 'h') {
2398 					qualifier = 'H';
2399 					fmt++;
2400 				} else if (qualifier == 'l') {
2401 					qualifier = 'L';
2402 					fmt++;
2403 				}
2404 			}
2405 		}
2406 
2407 		if (!*fmt)
2408 			break;
2409 
2410 		if (*fmt == 'n') {
2411 			/* return number of characters read so far */
2412 			*va_arg(args, int *) = str - buf;
2413 			++fmt;
2414 			continue;
2415 		}
2416 
2417 		if (!*str)
2418 			break;
2419 
2420 		base = 10;
2421 		is_sign = false;
2422 
2423 		switch (*fmt++) {
2424 		case 'c':
2425 		{
2426 			char *s = (char *)va_arg(args, char*);
2427 			if (field_width == -1)
2428 				field_width = 1;
2429 			do {
2430 				*s++ = *str++;
2431 			} while (--field_width > 0 && *str);
2432 			num++;
2433 		}
2434 		continue;
2435 		case 's':
2436 		{
2437 			char *s = (char *)va_arg(args, char *);
2438 			if (field_width == -1)
2439 				field_width = SHRT_MAX;
2440 			/* first, skip leading white space in buffer */
2441 			str = skip_spaces(str);
2442 
2443 			/* now copy until next white space */
2444 			while (*str && !isspace(*str) && field_width--)
2445 				*s++ = *str++;
2446 			*s = '\0';
2447 			num++;
2448 		}
2449 		continue;
2450 		case 'o':
2451 			base = 8;
2452 			break;
2453 		case 'x':
2454 		case 'X':
2455 			base = 16;
2456 			break;
2457 		case 'i':
2458 			base = 0;
2459 		case 'd':
2460 			is_sign = true;
2461 		case 'u':
2462 			break;
2463 		case '%':
2464 			/* looking for '%' in str */
2465 			if (*str++ != '%')
2466 				return num;
2467 			continue;
2468 		default:
2469 			/* invalid format; stop here */
2470 			return num;
2471 		}
2472 
2473 		/* have some sort of integer conversion.
2474 		 * first, skip white space in buffer.
2475 		 */
2476 		str = skip_spaces(str);
2477 
2478 		digit = *str;
2479 		if (is_sign && digit == '-')
2480 			digit = *(str + 1);
2481 
2482 		if (!digit
2483 		    || (base == 16 && !isxdigit(digit))
2484 		    || (base == 10 && !isdigit(digit))
2485 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
2486 		    || (base == 0 && !isdigit(digit)))
2487 			break;
2488 
2489 		if (is_sign)
2490 			val.s = qualifier != 'L' ?
2491 				simple_strtol(str, &next, base) :
2492 				simple_strtoll(str, &next, base);
2493 		else
2494 			val.u = qualifier != 'L' ?
2495 				simple_strtoul(str, &next, base) :
2496 				simple_strtoull(str, &next, base);
2497 
2498 		if (field_width > 0 && next - str > field_width) {
2499 			if (base == 0)
2500 				_parse_integer_fixup_radix(str, &base);
2501 			while (next - str > field_width) {
2502 				if (is_sign)
2503 					val.s = div_s64(val.s, base);
2504 				else
2505 					val.u = div_u64(val.u, base);
2506 				--next;
2507 			}
2508 		}
2509 
2510 		switch (qualifier) {
2511 		case 'H':	/* that's 'hh' in format */
2512 			if (is_sign)
2513 				*va_arg(args, signed char *) = val.s;
2514 			else
2515 				*va_arg(args, unsigned char *) = val.u;
2516 			break;
2517 		case 'h':
2518 			if (is_sign)
2519 				*va_arg(args, short *) = val.s;
2520 			else
2521 				*va_arg(args, unsigned short *) = val.u;
2522 			break;
2523 		case 'l':
2524 			if (is_sign)
2525 				*va_arg(args, long *) = val.s;
2526 			else
2527 				*va_arg(args, unsigned long *) = val.u;
2528 			break;
2529 		case 'L':
2530 			if (is_sign)
2531 				*va_arg(args, long long *) = val.s;
2532 			else
2533 				*va_arg(args, unsigned long long *) = val.u;
2534 			break;
2535 		case 'Z':
2536 		case 'z':
2537 			*va_arg(args, size_t *) = val.u;
2538 			break;
2539 		default:
2540 			if (is_sign)
2541 				*va_arg(args, int *) = val.s;
2542 			else
2543 				*va_arg(args, unsigned int *) = val.u;
2544 			break;
2545 		}
2546 		num++;
2547 
2548 		if (!next)
2549 			break;
2550 		str = next;
2551 	}
2552 
2553 	return num;
2554 }
2555 EXPORT_SYMBOL(vsscanf);
2556 
2557 /**
2558  * sscanf - Unformat a buffer into a list of arguments
2559  * @buf:	input buffer
2560  * @fmt:	formatting of buffer
2561  * @...:	resulting arguments
2562  */
2563 int sscanf(const char *buf, const char *fmt, ...)
2564 {
2565 	va_list args;
2566 	int i;
2567 
2568 	va_start(args, fmt);
2569 	i = vsscanf(buf, fmt, args);
2570 	va_end(args);
2571 
2572 	return i;
2573 }
2574 EXPORT_SYMBOL(sscanf);
2575