xref: /linux/lib/vsprintf.c (revision 2da572c959dd5815aef153cf62010b16a498a0d3)
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/clk-provider.h>
21 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/ctype.h>
25 #include <linux/kernel.h>
26 #include <linux/kallsyms.h>
27 #include <linux/math64.h>
28 #include <linux/uaccess.h>
29 #include <linux/ioport.h>
30 #include <linux/dcache.h>
31 #include <linux/cred.h>
32 #include <net/addrconf.h>
33 
34 #include <asm/page.h>		/* for PAGE_SIZE */
35 #include <asm/sections.h>	/* for dereference_function_descriptor() */
36 
37 #include <linux/string_helpers.h>
38 #include "kstrtox.h"
39 
40 /**
41  * simple_strtoull - convert a string to an unsigned long long
42  * @cp: The start of the string
43  * @endp: A pointer to the end of the parsed string will be placed here
44  * @base: The number base to use
45  *
46  * This function is obsolete. Please use kstrtoull instead.
47  */
48 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
49 {
50 	unsigned long long result;
51 	unsigned int rv;
52 
53 	cp = _parse_integer_fixup_radix(cp, &base);
54 	rv = _parse_integer(cp, base, &result);
55 	/* FIXME */
56 	cp += (rv & ~KSTRTOX_OVERFLOW);
57 
58 	if (endp)
59 		*endp = (char *)cp;
60 
61 	return result;
62 }
63 EXPORT_SYMBOL(simple_strtoull);
64 
65 /**
66  * simple_strtoul - convert a string to an unsigned long
67  * @cp: The start of the string
68  * @endp: A pointer to the end of the parsed string will be placed here
69  * @base: The number base to use
70  *
71  * This function is obsolete. Please use kstrtoul instead.
72  */
73 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
74 {
75 	return simple_strtoull(cp, endp, base);
76 }
77 EXPORT_SYMBOL(simple_strtoul);
78 
79 /**
80  * simple_strtol - convert a string to a signed long
81  * @cp: The start of the string
82  * @endp: A pointer to the end of the parsed string will be placed here
83  * @base: The number base to use
84  *
85  * This function is obsolete. Please use kstrtol instead.
86  */
87 long simple_strtol(const char *cp, char **endp, unsigned int base)
88 {
89 	if (*cp == '-')
90 		return -simple_strtoul(cp + 1, endp, base);
91 
92 	return simple_strtoul(cp, endp, base);
93 }
94 EXPORT_SYMBOL(simple_strtol);
95 
96 /**
97  * simple_strtoll - convert a string to a signed long long
98  * @cp: The start of the string
99  * @endp: A pointer to the end of the parsed string will be placed here
100  * @base: The number base to use
101  *
102  * This function is obsolete. Please use kstrtoll instead.
103  */
104 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
105 {
106 	if (*cp == '-')
107 		return -simple_strtoull(cp + 1, endp, base);
108 
109 	return simple_strtoull(cp, endp, base);
110 }
111 EXPORT_SYMBOL(simple_strtoll);
112 
113 static noinline_for_stack
114 int skip_atoi(const char **s)
115 {
116 	int i = 0;
117 
118 	do {
119 		i = i*10 + *((*s)++) - '0';
120 	} while (isdigit(**s));
121 
122 	return i;
123 }
124 
125 /* Decimal conversion is by far the most typical, and is used
126  * for /proc and /sys data. This directly impacts e.g. top performance
127  * with many processes running. We optimize it for speed
128  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
129  * (with permission from the author, Douglas W. Jones).
130  */
131 
132 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
133 /* Formats correctly any integer in [0, 999999999] */
134 static noinline_for_stack
135 char *put_dec_full9(char *buf, unsigned q)
136 {
137 	unsigned r;
138 
139 	/*
140 	 * Possible ways to approx. divide by 10
141 	 * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
142 	 * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
143 	 * (x * 0x6667) >> 18     x <      43699
144 	 * (x * 0x3334) >> 17     x <      16389
145 	 * (x * 0x199a) >> 16     x <      16389
146 	 * (x * 0x0ccd) >> 15     x <      16389
147 	 * (x * 0x0667) >> 14     x <       2739
148 	 * (x * 0x0334) >> 13     x <       1029
149 	 * (x * 0x019a) >> 12     x <       1029
150 	 * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
151 	 * (x * 0x0067) >> 10     x <        179
152 	 * (x * 0x0034) >>  9     x <         69 same
153 	 * (x * 0x001a) >>  8     x <         69 same
154 	 * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
155 	 * (x * 0x0007) >>  6     x <         19
156 	 * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
157 	 */
158 	r      = (q * (uint64_t)0x1999999a) >> 32;
159 	*buf++ = (q - 10 * r) + '0'; /* 1 */
160 	q      = (r * (uint64_t)0x1999999a) >> 32;
161 	*buf++ = (r - 10 * q) + '0'; /* 2 */
162 	r      = (q * (uint64_t)0x1999999a) >> 32;
163 	*buf++ = (q - 10 * r) + '0'; /* 3 */
164 	q      = (r * (uint64_t)0x1999999a) >> 32;
165 	*buf++ = (r - 10 * q) + '0'; /* 4 */
166 	r      = (q * (uint64_t)0x1999999a) >> 32;
167 	*buf++ = (q - 10 * r) + '0'; /* 5 */
168 	/* Now value is under 10000, can avoid 64-bit multiply */
169 	q      = (r * 0x199a) >> 16;
170 	*buf++ = (r - 10 * q)  + '0'; /* 6 */
171 	r      = (q * 0xcd) >> 11;
172 	*buf++ = (q - 10 * r)  + '0'; /* 7 */
173 	q      = (r * 0xcd) >> 11;
174 	*buf++ = (r - 10 * q) + '0'; /* 8 */
175 	*buf++ = q + '0'; /* 9 */
176 	return buf;
177 }
178 #endif
179 
180 /* Similar to above but do not pad with zeros.
181  * Code can be easily arranged to print 9 digits too, but our callers
182  * always call put_dec_full9() instead when the number has 9 decimal digits.
183  */
184 static noinline_for_stack
185 char *put_dec_trunc8(char *buf, unsigned r)
186 {
187 	unsigned q;
188 
189 	/* Copy of previous function's body with added early returns */
190 	while (r >= 10000) {
191 		q = r + '0';
192 		r  = (r * (uint64_t)0x1999999a) >> 32;
193 		*buf++ = q - 10*r;
194 	}
195 
196 	q      = (r * 0x199a) >> 16;	/* r <= 9999 */
197 	*buf++ = (r - 10 * q)  + '0';
198 	if (q == 0)
199 		return buf;
200 	r      = (q * 0xcd) >> 11;	/* q <= 999 */
201 	*buf++ = (q - 10 * r)  + '0';
202 	if (r == 0)
203 		return buf;
204 	q      = (r * 0xcd) >> 11;	/* r <= 99 */
205 	*buf++ = (r - 10 * q) + '0';
206 	if (q == 0)
207 		return buf;
208 	*buf++ = q + '0';		 /* q <= 9 */
209 	return buf;
210 }
211 
212 /* There are two algorithms to print larger numbers.
213  * One is generic: divide by 1000000000 and repeatedly print
214  * groups of (up to) 9 digits. It's conceptually simple,
215  * but requires a (unsigned long long) / 1000000000 division.
216  *
217  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
218  * manipulates them cleverly and generates groups of 4 decimal digits.
219  * It so happens that it does NOT require long long division.
220  *
221  * If long is > 32 bits, division of 64-bit values is relatively easy,
222  * and we will use the first algorithm.
223  * If long long is > 64 bits (strange architecture with VERY large long long),
224  * second algorithm can't be used, and we again use the first one.
225  *
226  * Else (if long is 32 bits and long long is 64 bits) we use second one.
227  */
228 
229 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
230 
231 /* First algorithm: generic */
232 
233 static
234 char *put_dec(char *buf, unsigned long long n)
235 {
236 	if (n >= 100*1000*1000) {
237 		while (n >= 1000*1000*1000)
238 			buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
239 		if (n >= 100*1000*1000)
240 			return put_dec_full9(buf, n);
241 	}
242 	return put_dec_trunc8(buf, n);
243 }
244 
245 #else
246 
247 /* Second algorithm: valid only for 64-bit long longs */
248 
249 /* See comment in put_dec_full9 for choice of constants */
250 static noinline_for_stack
251 void put_dec_full4(char *buf, unsigned q)
252 {
253 	unsigned r;
254 	r      = (q * 0xccd) >> 15;
255 	buf[0] = (q - 10 * r) + '0';
256 	q      = (r * 0xcd) >> 11;
257 	buf[1] = (r - 10 * q)  + '0';
258 	r      = (q * 0xcd) >> 11;
259 	buf[2] = (q - 10 * r)  + '0';
260 	buf[3] = r + '0';
261 }
262 
263 /*
264  * Call put_dec_full4 on x % 10000, return x / 10000.
265  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
266  * holds for all x < 1,128,869,999.  The largest value this
267  * helper will ever be asked to convert is 1,125,520,955.
268  * (d1 in the put_dec code, assuming n is all-ones).
269  */
270 static
271 unsigned put_dec_helper4(char *buf, unsigned x)
272 {
273         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
274 
275         put_dec_full4(buf, x - q * 10000);
276         return q;
277 }
278 
279 /* Based on code by Douglas W. Jones found at
280  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
281  * (with permission from the author).
282  * Performs no 64-bit division and hence should be fast on 32-bit machines.
283  */
284 static
285 char *put_dec(char *buf, unsigned long long n)
286 {
287 	uint32_t d3, d2, d1, q, h;
288 
289 	if (n < 100*1000*1000)
290 		return put_dec_trunc8(buf, n);
291 
292 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
293 	h   = (n >> 32);
294 	d2  = (h      ) & 0xffff;
295 	d3  = (h >> 16); /* implicit "& 0xffff" */
296 
297 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
298 	q = put_dec_helper4(buf, q);
299 
300 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
301 	q = put_dec_helper4(buf+4, q);
302 
303 	q += 4749 * d3 + 42 * d2;
304 	q = put_dec_helper4(buf+8, q);
305 
306 	q += 281 * d3;
307 	buf += 12;
308 	if (q)
309 		buf = put_dec_trunc8(buf, q);
310 	else while (buf[-1] == '0')
311 		--buf;
312 
313 	return buf;
314 }
315 
316 #endif
317 
318 /*
319  * Convert passed number to decimal string.
320  * Returns the length of string.  On buffer overflow, returns 0.
321  *
322  * If speed is not important, use snprintf(). It's easy to read the code.
323  */
324 int num_to_str(char *buf, int size, unsigned long long num)
325 {
326 	char tmp[sizeof(num) * 3];
327 	int idx, len;
328 
329 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
330 	if (num <= 9) {
331 		tmp[0] = '0' + num;
332 		len = 1;
333 	} else {
334 		len = put_dec(tmp, num) - tmp;
335 	}
336 
337 	if (len > size)
338 		return 0;
339 	for (idx = 0; idx < len; ++idx)
340 		buf[idx] = tmp[len - idx - 1];
341 	return len;
342 }
343 
344 #define SIGN	1		/* unsigned/signed, must be 1 */
345 #define LEFT	2		/* left justified */
346 #define PLUS	4		/* show plus */
347 #define SPACE	8		/* space if plus */
348 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
349 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
350 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
351 
352 enum format_type {
353 	FORMAT_TYPE_NONE, /* Just a string part */
354 	FORMAT_TYPE_WIDTH,
355 	FORMAT_TYPE_PRECISION,
356 	FORMAT_TYPE_CHAR,
357 	FORMAT_TYPE_STR,
358 	FORMAT_TYPE_PTR,
359 	FORMAT_TYPE_PERCENT_CHAR,
360 	FORMAT_TYPE_INVALID,
361 	FORMAT_TYPE_LONG_LONG,
362 	FORMAT_TYPE_ULONG,
363 	FORMAT_TYPE_LONG,
364 	FORMAT_TYPE_UBYTE,
365 	FORMAT_TYPE_BYTE,
366 	FORMAT_TYPE_USHORT,
367 	FORMAT_TYPE_SHORT,
368 	FORMAT_TYPE_UINT,
369 	FORMAT_TYPE_INT,
370 	FORMAT_TYPE_SIZE_T,
371 	FORMAT_TYPE_PTRDIFF
372 };
373 
374 struct printf_spec {
375 	u8	type;		/* format_type enum */
376 	u8	flags;		/* flags to number() */
377 	u8	base;		/* number base, 8, 10 or 16 only */
378 	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
379 	s16	field_width;	/* width of output field */
380 	s16	precision;	/* # of digits/chars */
381 };
382 
383 static noinline_for_stack
384 char *number(char *buf, char *end, unsigned long long num,
385 	     struct printf_spec spec)
386 {
387 	char tmp[3 * sizeof(num)];
388 	char sign;
389 	char locase;
390 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
391 	int i;
392 	bool is_zero = num == 0LL;
393 
394 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
395 	 * produces same digits or (maybe lowercased) letters */
396 	locase = (spec.flags & SMALL);
397 	if (spec.flags & LEFT)
398 		spec.flags &= ~ZEROPAD;
399 	sign = 0;
400 	if (spec.flags & SIGN) {
401 		if ((signed long long)num < 0) {
402 			sign = '-';
403 			num = -(signed long long)num;
404 			spec.field_width--;
405 		} else if (spec.flags & PLUS) {
406 			sign = '+';
407 			spec.field_width--;
408 		} else if (spec.flags & SPACE) {
409 			sign = ' ';
410 			spec.field_width--;
411 		}
412 	}
413 	if (need_pfx) {
414 		if (spec.base == 16)
415 			spec.field_width -= 2;
416 		else if (!is_zero)
417 			spec.field_width--;
418 	}
419 
420 	/* generate full string in tmp[], in reverse order */
421 	i = 0;
422 	if (num < spec.base)
423 		tmp[i++] = hex_asc_upper[num] | locase;
424 	else if (spec.base != 10) { /* 8 or 16 */
425 		int mask = spec.base - 1;
426 		int shift = 3;
427 
428 		if (spec.base == 16)
429 			shift = 4;
430 		do {
431 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
432 			num >>= shift;
433 		} while (num);
434 	} else { /* base 10 */
435 		i = put_dec(tmp, num) - tmp;
436 	}
437 
438 	/* printing 100 using %2d gives "100", not "00" */
439 	if (i > spec.precision)
440 		spec.precision = i;
441 	/* leading space padding */
442 	spec.field_width -= spec.precision;
443 	if (!(spec.flags & (ZEROPAD | LEFT))) {
444 		while (--spec.field_width >= 0) {
445 			if (buf < end)
446 				*buf = ' ';
447 			++buf;
448 		}
449 	}
450 	/* sign */
451 	if (sign) {
452 		if (buf < end)
453 			*buf = sign;
454 		++buf;
455 	}
456 	/* "0x" / "0" prefix */
457 	if (need_pfx) {
458 		if (spec.base == 16 || !is_zero) {
459 			if (buf < end)
460 				*buf = '0';
461 			++buf;
462 		}
463 		if (spec.base == 16) {
464 			if (buf < end)
465 				*buf = ('X' | locase);
466 			++buf;
467 		}
468 	}
469 	/* zero or space padding */
470 	if (!(spec.flags & LEFT)) {
471 		char c = ' ' + (spec.flags & ZEROPAD);
472 		BUILD_BUG_ON(' ' + ZEROPAD != '0');
473 		while (--spec.field_width >= 0) {
474 			if (buf < end)
475 				*buf = c;
476 			++buf;
477 		}
478 	}
479 	/* hmm even more zero padding? */
480 	while (i <= --spec.precision) {
481 		if (buf < end)
482 			*buf = '0';
483 		++buf;
484 	}
485 	/* actual digits of result */
486 	while (--i >= 0) {
487 		if (buf < end)
488 			*buf = tmp[i];
489 		++buf;
490 	}
491 	/* trailing space padding */
492 	while (--spec.field_width >= 0) {
493 		if (buf < end)
494 			*buf = ' ';
495 		++buf;
496 	}
497 
498 	return buf;
499 }
500 
501 static noinline_for_stack
502 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
503 {
504 	int len, i;
505 
506 	if ((unsigned long)s < PAGE_SIZE)
507 		s = "(null)";
508 
509 	len = strnlen(s, spec.precision);
510 
511 	if (!(spec.flags & LEFT)) {
512 		while (len < spec.field_width--) {
513 			if (buf < end)
514 				*buf = ' ';
515 			++buf;
516 		}
517 	}
518 	for (i = 0; i < len; ++i) {
519 		if (buf < end)
520 			*buf = *s;
521 		++buf; ++s;
522 	}
523 	while (len < spec.field_width--) {
524 		if (buf < end)
525 			*buf = ' ';
526 		++buf;
527 	}
528 
529 	return buf;
530 }
531 
532 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
533 {
534 	size_t size;
535 	if (buf >= end)	/* nowhere to put anything */
536 		return;
537 	size = end - buf;
538 	if (size <= spaces) {
539 		memset(buf, ' ', size);
540 		return;
541 	}
542 	if (len) {
543 		if (len > size - spaces)
544 			len = size - spaces;
545 		memmove(buf + spaces, buf, len);
546 	}
547 	memset(buf, ' ', spaces);
548 }
549 
550 static noinline_for_stack
551 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
552 		  const char *fmt)
553 {
554 	const char *array[4], *s;
555 	const struct dentry *p;
556 	int depth;
557 	int i, n;
558 
559 	switch (fmt[1]) {
560 		case '2': case '3': case '4':
561 			depth = fmt[1] - '0';
562 			break;
563 		default:
564 			depth = 1;
565 	}
566 
567 	rcu_read_lock();
568 	for (i = 0; i < depth; i++, d = p) {
569 		p = ACCESS_ONCE(d->d_parent);
570 		array[i] = ACCESS_ONCE(d->d_name.name);
571 		if (p == d) {
572 			if (i)
573 				array[i] = "";
574 			i++;
575 			break;
576 		}
577 	}
578 	s = array[--i];
579 	for (n = 0; n != spec.precision; n++, buf++) {
580 		char c = *s++;
581 		if (!c) {
582 			if (!i)
583 				break;
584 			c = '/';
585 			s = array[--i];
586 		}
587 		if (buf < end)
588 			*buf = c;
589 	}
590 	rcu_read_unlock();
591 	if (n < spec.field_width) {
592 		/* we want to pad the sucker */
593 		unsigned spaces = spec.field_width - n;
594 		if (!(spec.flags & LEFT)) {
595 			widen(buf - n, end, n, spaces);
596 			return buf + spaces;
597 		}
598 		while (spaces--) {
599 			if (buf < end)
600 				*buf = ' ';
601 			++buf;
602 		}
603 	}
604 	return buf;
605 }
606 
607 static noinline_for_stack
608 char *symbol_string(char *buf, char *end, void *ptr,
609 		    struct printf_spec spec, const char *fmt)
610 {
611 	unsigned long value;
612 #ifdef CONFIG_KALLSYMS
613 	char sym[KSYM_SYMBOL_LEN];
614 #endif
615 
616 	if (fmt[1] == 'R')
617 		ptr = __builtin_extract_return_addr(ptr);
618 	value = (unsigned long)ptr;
619 
620 #ifdef CONFIG_KALLSYMS
621 	if (*fmt == 'B')
622 		sprint_backtrace(sym, value);
623 	else if (*fmt != 'f' && *fmt != 's')
624 		sprint_symbol(sym, value);
625 	else
626 		sprint_symbol_no_offset(sym, value);
627 
628 	return string(buf, end, sym, spec);
629 #else
630 	spec.field_width = 2 * sizeof(void *);
631 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
632 	spec.base = 16;
633 
634 	return number(buf, end, value, spec);
635 #endif
636 }
637 
638 static noinline_for_stack
639 char *resource_string(char *buf, char *end, struct resource *res,
640 		      struct printf_spec spec, const char *fmt)
641 {
642 #ifndef IO_RSRC_PRINTK_SIZE
643 #define IO_RSRC_PRINTK_SIZE	6
644 #endif
645 
646 #ifndef MEM_RSRC_PRINTK_SIZE
647 #define MEM_RSRC_PRINTK_SIZE	10
648 #endif
649 	static const struct printf_spec io_spec = {
650 		.base = 16,
651 		.field_width = IO_RSRC_PRINTK_SIZE,
652 		.precision = -1,
653 		.flags = SPECIAL | SMALL | ZEROPAD,
654 	};
655 	static const struct printf_spec mem_spec = {
656 		.base = 16,
657 		.field_width = MEM_RSRC_PRINTK_SIZE,
658 		.precision = -1,
659 		.flags = SPECIAL | SMALL | ZEROPAD,
660 	};
661 	static const struct printf_spec bus_spec = {
662 		.base = 16,
663 		.field_width = 2,
664 		.precision = -1,
665 		.flags = SMALL | ZEROPAD,
666 	};
667 	static const struct printf_spec dec_spec = {
668 		.base = 10,
669 		.precision = -1,
670 		.flags = 0,
671 	};
672 	static const struct printf_spec str_spec = {
673 		.field_width = -1,
674 		.precision = 10,
675 		.flags = LEFT,
676 	};
677 	static const struct printf_spec flag_spec = {
678 		.base = 16,
679 		.precision = -1,
680 		.flags = SPECIAL | SMALL,
681 	};
682 
683 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
684 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
685 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
686 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
687 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
688 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
689 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
690 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
691 
692 	char *p = sym, *pend = sym + sizeof(sym);
693 	int decode = (fmt[0] == 'R') ? 1 : 0;
694 	const struct printf_spec *specp;
695 
696 	*p++ = '[';
697 	if (res->flags & IORESOURCE_IO) {
698 		p = string(p, pend, "io  ", str_spec);
699 		specp = &io_spec;
700 	} else if (res->flags & IORESOURCE_MEM) {
701 		p = string(p, pend, "mem ", str_spec);
702 		specp = &mem_spec;
703 	} else if (res->flags & IORESOURCE_IRQ) {
704 		p = string(p, pend, "irq ", str_spec);
705 		specp = &dec_spec;
706 	} else if (res->flags & IORESOURCE_DMA) {
707 		p = string(p, pend, "dma ", str_spec);
708 		specp = &dec_spec;
709 	} else if (res->flags & IORESOURCE_BUS) {
710 		p = string(p, pend, "bus ", str_spec);
711 		specp = &bus_spec;
712 	} else {
713 		p = string(p, pend, "??? ", str_spec);
714 		specp = &mem_spec;
715 		decode = 0;
716 	}
717 	if (decode && res->flags & IORESOURCE_UNSET) {
718 		p = string(p, pend, "size ", str_spec);
719 		p = number(p, pend, resource_size(res), *specp);
720 	} else {
721 		p = number(p, pend, res->start, *specp);
722 		if (res->start != res->end) {
723 			*p++ = '-';
724 			p = number(p, pend, res->end, *specp);
725 		}
726 	}
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; ++i) {
781 		if (buf < end)
782 			*buf = hex_asc_hi(addr[i]);
783 		++buf;
784 		if (buf < end)
785 			*buf = hex_asc_lo(addr[i]);
786 		++buf;
787 
788 		if (separator && i != len - 1) {
789 			if (buf < end)
790 				*buf = separator;
791 			++buf;
792 		}
793 	}
794 
795 	return buf;
796 }
797 
798 static noinline_for_stack
799 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
800 		    struct printf_spec spec, const char *fmt)
801 {
802 	const int CHUNKSZ = 32;
803 	int nr_bits = max_t(int, spec.field_width, 0);
804 	int i, chunksz;
805 	bool first = true;
806 
807 	/* reused to print numbers */
808 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
809 
810 	chunksz = nr_bits & (CHUNKSZ - 1);
811 	if (chunksz == 0)
812 		chunksz = CHUNKSZ;
813 
814 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
815 	for (; i >= 0; i -= CHUNKSZ) {
816 		u32 chunkmask, val;
817 		int word, bit;
818 
819 		chunkmask = ((1ULL << chunksz) - 1);
820 		word = i / BITS_PER_LONG;
821 		bit = i % BITS_PER_LONG;
822 		val = (bitmap[word] >> bit) & chunkmask;
823 
824 		if (!first) {
825 			if (buf < end)
826 				*buf = ',';
827 			buf++;
828 		}
829 		first = false;
830 
831 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
832 		buf = number(buf, end, val, spec);
833 
834 		chunksz = CHUNKSZ;
835 	}
836 	return buf;
837 }
838 
839 static noinline_for_stack
840 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
841 			 struct printf_spec spec, const char *fmt)
842 {
843 	int nr_bits = max_t(int, spec.field_width, 0);
844 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
845 	int cur, rbot, rtop;
846 	bool first = true;
847 
848 	/* reused to print numbers */
849 	spec = (struct printf_spec){ .base = 10 };
850 
851 	rbot = cur = find_first_bit(bitmap, nr_bits);
852 	while (cur < nr_bits) {
853 		rtop = cur;
854 		cur = find_next_bit(bitmap, nr_bits, cur + 1);
855 		if (cur < nr_bits && cur <= rtop + 1)
856 			continue;
857 
858 		if (!first) {
859 			if (buf < end)
860 				*buf = ',';
861 			buf++;
862 		}
863 		first = false;
864 
865 		buf = number(buf, end, rbot, spec);
866 		if (rbot < rtop) {
867 			if (buf < end)
868 				*buf = '-';
869 			buf++;
870 
871 			buf = number(buf, end, rtop, spec);
872 		}
873 
874 		rbot = cur;
875 	}
876 	return buf;
877 }
878 
879 static noinline_for_stack
880 char *mac_address_string(char *buf, char *end, u8 *addr,
881 			 struct printf_spec spec, const char *fmt)
882 {
883 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
884 	char *p = mac_addr;
885 	int i;
886 	char separator;
887 	bool reversed = false;
888 
889 	switch (fmt[1]) {
890 	case 'F':
891 		separator = '-';
892 		break;
893 
894 	case 'R':
895 		reversed = true;
896 		/* fall through */
897 
898 	default:
899 		separator = ':';
900 		break;
901 	}
902 
903 	for (i = 0; i < 6; i++) {
904 		if (reversed)
905 			p = hex_byte_pack(p, addr[5 - i]);
906 		else
907 			p = hex_byte_pack(p, addr[i]);
908 
909 		if (fmt[0] == 'M' && i != 5)
910 			*p++ = separator;
911 	}
912 	*p = '\0';
913 
914 	return string(buf, end, mac_addr, spec);
915 }
916 
917 static noinline_for_stack
918 char *ip4_string(char *p, const u8 *addr, const char *fmt)
919 {
920 	int i;
921 	bool leading_zeros = (fmt[0] == 'i');
922 	int index;
923 	int step;
924 
925 	switch (fmt[2]) {
926 	case 'h':
927 #ifdef __BIG_ENDIAN
928 		index = 0;
929 		step = 1;
930 #else
931 		index = 3;
932 		step = -1;
933 #endif
934 		break;
935 	case 'l':
936 		index = 3;
937 		step = -1;
938 		break;
939 	case 'n':
940 	case 'b':
941 	default:
942 		index = 0;
943 		step = 1;
944 		break;
945 	}
946 	for (i = 0; i < 4; i++) {
947 		char temp[3];	/* hold each IP quad in reverse order */
948 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
949 		if (leading_zeros) {
950 			if (digits < 3)
951 				*p++ = '0';
952 			if (digits < 2)
953 				*p++ = '0';
954 		}
955 		/* reverse the digits in the quad */
956 		while (digits--)
957 			*p++ = temp[digits];
958 		if (i < 3)
959 			*p++ = '.';
960 		index += step;
961 	}
962 	*p = '\0';
963 
964 	return p;
965 }
966 
967 static noinline_for_stack
968 char *ip6_compressed_string(char *p, const char *addr)
969 {
970 	int i, j, range;
971 	unsigned char zerolength[8];
972 	int longest = 1;
973 	int colonpos = -1;
974 	u16 word;
975 	u8 hi, lo;
976 	bool needcolon = false;
977 	bool useIPv4;
978 	struct in6_addr in6;
979 
980 	memcpy(&in6, addr, sizeof(struct in6_addr));
981 
982 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
983 
984 	memset(zerolength, 0, sizeof(zerolength));
985 
986 	if (useIPv4)
987 		range = 6;
988 	else
989 		range = 8;
990 
991 	/* find position of longest 0 run */
992 	for (i = 0; i < range; i++) {
993 		for (j = i; j < range; j++) {
994 			if (in6.s6_addr16[j] != 0)
995 				break;
996 			zerolength[i]++;
997 		}
998 	}
999 	for (i = 0; i < range; i++) {
1000 		if (zerolength[i] > longest) {
1001 			longest = zerolength[i];
1002 			colonpos = i;
1003 		}
1004 	}
1005 	if (longest == 1)		/* don't compress a single 0 */
1006 		colonpos = -1;
1007 
1008 	/* emit address */
1009 	for (i = 0; i < range; i++) {
1010 		if (i == colonpos) {
1011 			if (needcolon || i == 0)
1012 				*p++ = ':';
1013 			*p++ = ':';
1014 			needcolon = false;
1015 			i += longest - 1;
1016 			continue;
1017 		}
1018 		if (needcolon) {
1019 			*p++ = ':';
1020 			needcolon = false;
1021 		}
1022 		/* hex u16 without leading 0s */
1023 		word = ntohs(in6.s6_addr16[i]);
1024 		hi = word >> 8;
1025 		lo = word & 0xff;
1026 		if (hi) {
1027 			if (hi > 0x0f)
1028 				p = hex_byte_pack(p, hi);
1029 			else
1030 				*p++ = hex_asc_lo(hi);
1031 			p = hex_byte_pack(p, lo);
1032 		}
1033 		else if (lo > 0x0f)
1034 			p = hex_byte_pack(p, lo);
1035 		else
1036 			*p++ = hex_asc_lo(lo);
1037 		needcolon = true;
1038 	}
1039 
1040 	if (useIPv4) {
1041 		if (needcolon)
1042 			*p++ = ':';
1043 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1044 	}
1045 	*p = '\0';
1046 
1047 	return p;
1048 }
1049 
1050 static noinline_for_stack
1051 char *ip6_string(char *p, const char *addr, const char *fmt)
1052 {
1053 	int i;
1054 
1055 	for (i = 0; i < 8; i++) {
1056 		p = hex_byte_pack(p, *addr++);
1057 		p = hex_byte_pack(p, *addr++);
1058 		if (fmt[0] == 'I' && i != 7)
1059 			*p++ = ':';
1060 	}
1061 	*p = '\0';
1062 
1063 	return p;
1064 }
1065 
1066 static noinline_for_stack
1067 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1068 		      struct printf_spec spec, const char *fmt)
1069 {
1070 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1071 
1072 	if (fmt[0] == 'I' && fmt[2] == 'c')
1073 		ip6_compressed_string(ip6_addr, addr);
1074 	else
1075 		ip6_string(ip6_addr, addr, fmt);
1076 
1077 	return string(buf, end, ip6_addr, spec);
1078 }
1079 
1080 static noinline_for_stack
1081 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1082 		      struct printf_spec spec, const char *fmt)
1083 {
1084 	char ip4_addr[sizeof("255.255.255.255")];
1085 
1086 	ip4_string(ip4_addr, addr, fmt);
1087 
1088 	return string(buf, end, ip4_addr, spec);
1089 }
1090 
1091 static noinline_for_stack
1092 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1093 			 struct printf_spec spec, const char *fmt)
1094 {
1095 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1096 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1097 		      sizeof(":12345") + sizeof("/123456789") +
1098 		      sizeof("%1234567890")];
1099 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1100 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1101 	char fmt6[2] = { fmt[0], '6' };
1102 	u8 off = 0;
1103 
1104 	fmt++;
1105 	while (isalpha(*++fmt)) {
1106 		switch (*fmt) {
1107 		case 'p':
1108 			have_p = true;
1109 			break;
1110 		case 'f':
1111 			have_f = true;
1112 			break;
1113 		case 's':
1114 			have_s = true;
1115 			break;
1116 		case 'c':
1117 			have_c = true;
1118 			break;
1119 		}
1120 	}
1121 
1122 	if (have_p || have_s || have_f) {
1123 		*p = '[';
1124 		off = 1;
1125 	}
1126 
1127 	if (fmt6[0] == 'I' && have_c)
1128 		p = ip6_compressed_string(ip6_addr + off, addr);
1129 	else
1130 		p = ip6_string(ip6_addr + off, addr, fmt6);
1131 
1132 	if (have_p || have_s || have_f)
1133 		*p++ = ']';
1134 
1135 	if (have_p) {
1136 		*p++ = ':';
1137 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1138 	}
1139 	if (have_f) {
1140 		*p++ = '/';
1141 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1142 					  IPV6_FLOWINFO_MASK), spec);
1143 	}
1144 	if (have_s) {
1145 		*p++ = '%';
1146 		p = number(p, pend, sa->sin6_scope_id, spec);
1147 	}
1148 	*p = '\0';
1149 
1150 	return string(buf, end, ip6_addr, spec);
1151 }
1152 
1153 static noinline_for_stack
1154 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1155 			 struct printf_spec spec, const char *fmt)
1156 {
1157 	bool have_p = false;
1158 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1159 	char *pend = ip4_addr + sizeof(ip4_addr);
1160 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1161 	char fmt4[3] = { fmt[0], '4', 0 };
1162 
1163 	fmt++;
1164 	while (isalpha(*++fmt)) {
1165 		switch (*fmt) {
1166 		case 'p':
1167 			have_p = true;
1168 			break;
1169 		case 'h':
1170 		case 'l':
1171 		case 'n':
1172 		case 'b':
1173 			fmt4[2] = *fmt;
1174 			break;
1175 		}
1176 	}
1177 
1178 	p = ip4_string(ip4_addr, addr, fmt4);
1179 	if (have_p) {
1180 		*p++ = ':';
1181 		p = number(p, pend, ntohs(sa->sin_port), spec);
1182 	}
1183 	*p = '\0';
1184 
1185 	return string(buf, end, ip4_addr, spec);
1186 }
1187 
1188 static noinline_for_stack
1189 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1190 		     const char *fmt)
1191 {
1192 	bool found = true;
1193 	int count = 1;
1194 	unsigned int flags = 0;
1195 	int len;
1196 
1197 	if (spec.field_width == 0)
1198 		return buf;				/* nothing to print */
1199 
1200 	if (ZERO_OR_NULL_PTR(addr))
1201 		return string(buf, end, NULL, spec);	/* NULL pointer */
1202 
1203 
1204 	do {
1205 		switch (fmt[count++]) {
1206 		case 'a':
1207 			flags |= ESCAPE_ANY;
1208 			break;
1209 		case 'c':
1210 			flags |= ESCAPE_SPECIAL;
1211 			break;
1212 		case 'h':
1213 			flags |= ESCAPE_HEX;
1214 			break;
1215 		case 'n':
1216 			flags |= ESCAPE_NULL;
1217 			break;
1218 		case 'o':
1219 			flags |= ESCAPE_OCTAL;
1220 			break;
1221 		case 'p':
1222 			flags |= ESCAPE_NP;
1223 			break;
1224 		case 's':
1225 			flags |= ESCAPE_SPACE;
1226 			break;
1227 		default:
1228 			found = false;
1229 			break;
1230 		}
1231 	} while (found);
1232 
1233 	if (!flags)
1234 		flags = ESCAPE_ANY_NP;
1235 
1236 	len = spec.field_width < 0 ? 1 : spec.field_width;
1237 
1238 	/*
1239 	 * string_escape_mem() writes as many characters as it can to
1240 	 * the given buffer, and returns the total size of the output
1241 	 * had the buffer been big enough.
1242 	 */
1243 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1244 
1245 	return buf;
1246 }
1247 
1248 static noinline_for_stack
1249 char *uuid_string(char *buf, char *end, const u8 *addr,
1250 		  struct printf_spec spec, const char *fmt)
1251 {
1252 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1253 	char *p = uuid;
1254 	int i;
1255 	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1256 	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1257 	const u8 *index = be;
1258 	bool uc = false;
1259 
1260 	switch (*(++fmt)) {
1261 	case 'L':
1262 		uc = true;		/* fall-through */
1263 	case 'l':
1264 		index = le;
1265 		break;
1266 	case 'B':
1267 		uc = true;
1268 		break;
1269 	}
1270 
1271 	for (i = 0; i < 16; i++) {
1272 		p = hex_byte_pack(p, addr[index[i]]);
1273 		switch (i) {
1274 		case 3:
1275 		case 5:
1276 		case 7:
1277 		case 9:
1278 			*p++ = '-';
1279 			break;
1280 		}
1281 	}
1282 
1283 	*p = 0;
1284 
1285 	if (uc) {
1286 		p = uuid;
1287 		do {
1288 			*p = toupper(*p);
1289 		} while (*(++p));
1290 	}
1291 
1292 	return string(buf, end, uuid, spec);
1293 }
1294 
1295 static
1296 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1297 		      struct printf_spec spec)
1298 {
1299 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1300 	if (spec.field_width == -1)
1301 		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1302 	spec.base = 16;
1303 
1304 	return number(buf, end, *(const netdev_features_t *)addr, spec);
1305 }
1306 
1307 static noinline_for_stack
1308 char *address_val(char *buf, char *end, const void *addr,
1309 		  struct printf_spec spec, const char *fmt)
1310 {
1311 	unsigned long long num;
1312 
1313 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1314 	spec.base = 16;
1315 
1316 	switch (fmt[1]) {
1317 	case 'd':
1318 		num = *(const dma_addr_t *)addr;
1319 		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1320 		break;
1321 	case 'p':
1322 	default:
1323 		num = *(const phys_addr_t *)addr;
1324 		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1325 		break;
1326 	}
1327 
1328 	return number(buf, end, num, spec);
1329 }
1330 
1331 static noinline_for_stack
1332 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1333 	    const char *fmt)
1334 {
1335 	if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1336 		return string(buf, end, NULL, spec);
1337 
1338 	switch (fmt[1]) {
1339 	case 'r':
1340 		return number(buf, end, clk_get_rate(clk), spec);
1341 
1342 	case 'n':
1343 	default:
1344 #ifdef CONFIG_COMMON_CLK
1345 		return string(buf, end, __clk_get_name(clk), spec);
1346 #else
1347 		spec.base = 16;
1348 		spec.field_width = sizeof(unsigned long) * 2 + 2;
1349 		spec.flags |= SPECIAL | SMALL | ZEROPAD;
1350 		return number(buf, end, (unsigned long)clk, spec);
1351 #endif
1352 	}
1353 }
1354 
1355 int kptr_restrict __read_mostly;
1356 
1357 /*
1358  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1359  * by an extra set of alphanumeric characters that are extended format
1360  * specifiers.
1361  *
1362  * Right now we handle:
1363  *
1364  * - 'F' For symbolic function descriptor pointers with offset
1365  * - 'f' For simple symbolic function names without offset
1366  * - 'S' For symbolic direct pointers with offset
1367  * - 's' For symbolic direct pointers without offset
1368  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1369  * - 'B' For backtraced symbolic direct pointers with offset
1370  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1371  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1372  * - 'b[l]' For a bitmap, the number of bits is determined by the field
1373  *       width which must be explicitly specified either as part of the
1374  *       format string '%32b[l]' or through '%*b[l]', [l] selects
1375  *       range-list format instead of hex format
1376  * - 'M' For a 6-byte MAC address, it prints the address in the
1377  *       usual colon-separated hex notation
1378  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1379  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1380  *       with a dash-separated hex notation
1381  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1382  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1383  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1384  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1385  *       [S][pfs]
1386  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1387  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1388  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1389  *       IPv6 omits the colons (01020304...0f)
1390  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1391  *       [S][pfs]
1392  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1393  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1394  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1395  * - 'I[6S]c' for IPv6 addresses printed as specified by
1396  *       http://tools.ietf.org/html/rfc5952
1397  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1398  *                of the following flags (see string_escape_mem() for the
1399  *                details):
1400  *                  a - ESCAPE_ANY
1401  *                  c - ESCAPE_SPECIAL
1402  *                  h - ESCAPE_HEX
1403  *                  n - ESCAPE_NULL
1404  *                  o - ESCAPE_OCTAL
1405  *                  p - ESCAPE_NP
1406  *                  s - ESCAPE_SPACE
1407  *                By default ESCAPE_ANY_NP is used.
1408  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1409  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1410  *       Options for %pU are:
1411  *         b big endian lower case hex (default)
1412  *         B big endian UPPER case hex
1413  *         l little endian lower case hex
1414  *         L little endian UPPER case hex
1415  *           big endian output byte order is:
1416  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1417  *           little endian output byte order is:
1418  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1419  * - 'V' For a struct va_format which contains a format string * and va_list *,
1420  *       call vsnprintf(->format, *->va_list).
1421  *       Implements a "recursive vsnprintf".
1422  *       Do not use this feature without some mechanism to verify the
1423  *       correctness of the format string and va_list arguments.
1424  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1425  * - 'NF' For a netdev_features_t
1426  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1427  *            a certain separator (' ' by default):
1428  *              C colon
1429  *              D dash
1430  *              N no separator
1431  *            The maximum supported length is 64 bytes of the input. Consider
1432  *            to use print_hex_dump() for the larger input.
1433  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1434  *           (default assumed to be phys_addr_t, passed by reference)
1435  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1436  * - 'D[234]' Same as 'd' but for a struct file
1437  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1438  *       (legacy clock framework) of the clock
1439  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1440  *        (legacy clock framework) of the clock
1441  * - 'Cr' For a clock, it prints the current rate of the clock
1442  *
1443  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1444  * function pointers are really function descriptors, which contain a
1445  * pointer to the real address.
1446  */
1447 static noinline_for_stack
1448 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1449 	      struct printf_spec spec)
1450 {
1451 	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1452 
1453 	if (!ptr && *fmt != 'K') {
1454 		/*
1455 		 * Print (null) with the same width as a pointer so it makes
1456 		 * tabular output look nice.
1457 		 */
1458 		if (spec.field_width == -1)
1459 			spec.field_width = default_width;
1460 		return string(buf, end, "(null)", spec);
1461 	}
1462 
1463 	switch (*fmt) {
1464 	case 'F':
1465 	case 'f':
1466 		ptr = dereference_function_descriptor(ptr);
1467 		/* Fallthrough */
1468 	case 'S':
1469 	case 's':
1470 	case 'B':
1471 		return symbol_string(buf, end, ptr, spec, fmt);
1472 	case 'R':
1473 	case 'r':
1474 		return resource_string(buf, end, ptr, spec, fmt);
1475 	case 'h':
1476 		return hex_string(buf, end, ptr, spec, fmt);
1477 	case 'b':
1478 		switch (fmt[1]) {
1479 		case 'l':
1480 			return bitmap_list_string(buf, end, ptr, spec, fmt);
1481 		default:
1482 			return bitmap_string(buf, end, ptr, spec, fmt);
1483 		}
1484 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
1485 	case 'm':			/* Contiguous: 000102030405 */
1486 					/* [mM]F (FDDI) */
1487 					/* [mM]R (Reverse order; Bluetooth) */
1488 		return mac_address_string(buf, end, ptr, spec, fmt);
1489 	case 'I':			/* Formatted IP supported
1490 					 * 4:	1.2.3.4
1491 					 * 6:	0001:0203:...:0708
1492 					 * 6c:	1::708 or 1::1.2.3.4
1493 					 */
1494 	case 'i':			/* Contiguous:
1495 					 * 4:	001.002.003.004
1496 					 * 6:   000102...0f
1497 					 */
1498 		switch (fmt[1]) {
1499 		case '6':
1500 			return ip6_addr_string(buf, end, ptr, spec, fmt);
1501 		case '4':
1502 			return ip4_addr_string(buf, end, ptr, spec, fmt);
1503 		case 'S': {
1504 			const union {
1505 				struct sockaddr		raw;
1506 				struct sockaddr_in	v4;
1507 				struct sockaddr_in6	v6;
1508 			} *sa = ptr;
1509 
1510 			switch (sa->raw.sa_family) {
1511 			case AF_INET:
1512 				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1513 			case AF_INET6:
1514 				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1515 			default:
1516 				return string(buf, end, "(invalid address)", spec);
1517 			}}
1518 		}
1519 		break;
1520 	case 'E':
1521 		return escaped_string(buf, end, ptr, spec, fmt);
1522 	case 'U':
1523 		return uuid_string(buf, end, ptr, spec, fmt);
1524 	case 'V':
1525 		{
1526 			va_list va;
1527 
1528 			va_copy(va, *((struct va_format *)ptr)->va);
1529 			buf += vsnprintf(buf, end > buf ? end - buf : 0,
1530 					 ((struct va_format *)ptr)->fmt, va);
1531 			va_end(va);
1532 			return buf;
1533 		}
1534 	case 'K':
1535 		/*
1536 		 * %pK cannot be used in IRQ context because its test
1537 		 * for CAP_SYSLOG would be meaningless.
1538 		 */
1539 		if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1540 				      in_nmi())) {
1541 			if (spec.field_width == -1)
1542 				spec.field_width = default_width;
1543 			return string(buf, end, "pK-error", spec);
1544 		}
1545 
1546 		switch (kptr_restrict) {
1547 		case 0:
1548 			/* Always print %pK values */
1549 			break;
1550 		case 1: {
1551 			/*
1552 			 * Only print the real pointer value if the current
1553 			 * process has CAP_SYSLOG and is running with the
1554 			 * same credentials it started with. This is because
1555 			 * access to files is checked at open() time, but %pK
1556 			 * checks permission at read() time. We don't want to
1557 			 * leak pointer values if a binary opens a file using
1558 			 * %pK and then elevates privileges before reading it.
1559 			 */
1560 			const struct cred *cred = current_cred();
1561 
1562 			if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1563 			    !uid_eq(cred->euid, cred->uid) ||
1564 			    !gid_eq(cred->egid, cred->gid))
1565 				ptr = NULL;
1566 			break;
1567 		}
1568 		case 2:
1569 		default:
1570 			/* Always print 0's for %pK */
1571 			ptr = NULL;
1572 			break;
1573 		}
1574 		break;
1575 
1576 	case 'N':
1577 		switch (fmt[1]) {
1578 		case 'F':
1579 			return netdev_feature_string(buf, end, ptr, spec);
1580 		}
1581 		break;
1582 	case 'a':
1583 		return address_val(buf, end, ptr, spec, fmt);
1584 	case 'd':
1585 		return dentry_name(buf, end, ptr, spec, fmt);
1586 	case 'C':
1587 		return clock(buf, end, ptr, spec, fmt);
1588 	case 'D':
1589 		return dentry_name(buf, end,
1590 				   ((const struct file *)ptr)->f_path.dentry,
1591 				   spec, fmt);
1592 	}
1593 	spec.flags |= SMALL;
1594 	if (spec.field_width == -1) {
1595 		spec.field_width = default_width;
1596 		spec.flags |= ZEROPAD;
1597 	}
1598 	spec.base = 16;
1599 
1600 	return number(buf, end, (unsigned long) ptr, spec);
1601 }
1602 
1603 /*
1604  * Helper function to decode printf style format.
1605  * Each call decode a token from the format and return the
1606  * number of characters read (or likely the delta where it wants
1607  * to go on the next call).
1608  * The decoded token is returned through the parameters
1609  *
1610  * 'h', 'l', or 'L' for integer fields
1611  * 'z' support added 23/7/1999 S.H.
1612  * 'z' changed to 'Z' --davidm 1/25/99
1613  * 't' added for ptrdiff_t
1614  *
1615  * @fmt: the format string
1616  * @type of the token returned
1617  * @flags: various flags such as +, -, # tokens..
1618  * @field_width: overwritten width
1619  * @base: base of the number (octal, hex, ...)
1620  * @precision: precision of a number
1621  * @qualifier: qualifier of a number (long, size_t, ...)
1622  */
1623 static noinline_for_stack
1624 int format_decode(const char *fmt, struct printf_spec *spec)
1625 {
1626 	const char *start = fmt;
1627 
1628 	/* we finished early by reading the field width */
1629 	if (spec->type == FORMAT_TYPE_WIDTH) {
1630 		if (spec->field_width < 0) {
1631 			spec->field_width = -spec->field_width;
1632 			spec->flags |= LEFT;
1633 		}
1634 		spec->type = FORMAT_TYPE_NONE;
1635 		goto precision;
1636 	}
1637 
1638 	/* we finished early by reading the precision */
1639 	if (spec->type == FORMAT_TYPE_PRECISION) {
1640 		if (spec->precision < 0)
1641 			spec->precision = 0;
1642 
1643 		spec->type = FORMAT_TYPE_NONE;
1644 		goto qualifier;
1645 	}
1646 
1647 	/* By default */
1648 	spec->type = FORMAT_TYPE_NONE;
1649 
1650 	for (; *fmt ; ++fmt) {
1651 		if (*fmt == '%')
1652 			break;
1653 	}
1654 
1655 	/* Return the current non-format string */
1656 	if (fmt != start || !*fmt)
1657 		return fmt - start;
1658 
1659 	/* Process flags */
1660 	spec->flags = 0;
1661 
1662 	while (1) { /* this also skips first '%' */
1663 		bool found = true;
1664 
1665 		++fmt;
1666 
1667 		switch (*fmt) {
1668 		case '-': spec->flags |= LEFT;    break;
1669 		case '+': spec->flags |= PLUS;    break;
1670 		case ' ': spec->flags |= SPACE;   break;
1671 		case '#': spec->flags |= SPECIAL; break;
1672 		case '0': spec->flags |= ZEROPAD; break;
1673 		default:  found = false;
1674 		}
1675 
1676 		if (!found)
1677 			break;
1678 	}
1679 
1680 	/* get field width */
1681 	spec->field_width = -1;
1682 
1683 	if (isdigit(*fmt))
1684 		spec->field_width = skip_atoi(&fmt);
1685 	else if (*fmt == '*') {
1686 		/* it's the next argument */
1687 		spec->type = FORMAT_TYPE_WIDTH;
1688 		return ++fmt - start;
1689 	}
1690 
1691 precision:
1692 	/* get the precision */
1693 	spec->precision = -1;
1694 	if (*fmt == '.') {
1695 		++fmt;
1696 		if (isdigit(*fmt)) {
1697 			spec->precision = skip_atoi(&fmt);
1698 			if (spec->precision < 0)
1699 				spec->precision = 0;
1700 		} else if (*fmt == '*') {
1701 			/* it's the next argument */
1702 			spec->type = FORMAT_TYPE_PRECISION;
1703 			return ++fmt - start;
1704 		}
1705 	}
1706 
1707 qualifier:
1708 	/* get the conversion qualifier */
1709 	spec->qualifier = -1;
1710 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1711 	    _tolower(*fmt) == 'z' || *fmt == 't') {
1712 		spec->qualifier = *fmt++;
1713 		if (unlikely(spec->qualifier == *fmt)) {
1714 			if (spec->qualifier == 'l') {
1715 				spec->qualifier = 'L';
1716 				++fmt;
1717 			} else if (spec->qualifier == 'h') {
1718 				spec->qualifier = 'H';
1719 				++fmt;
1720 			}
1721 		}
1722 	}
1723 
1724 	/* default base */
1725 	spec->base = 10;
1726 	switch (*fmt) {
1727 	case 'c':
1728 		spec->type = FORMAT_TYPE_CHAR;
1729 		return ++fmt - start;
1730 
1731 	case 's':
1732 		spec->type = FORMAT_TYPE_STR;
1733 		return ++fmt - start;
1734 
1735 	case 'p':
1736 		spec->type = FORMAT_TYPE_PTR;
1737 		return ++fmt - start;
1738 
1739 	case '%':
1740 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1741 		return ++fmt - start;
1742 
1743 	/* integer number formats - set up the flags and "break" */
1744 	case 'o':
1745 		spec->base = 8;
1746 		break;
1747 
1748 	case 'x':
1749 		spec->flags |= SMALL;
1750 
1751 	case 'X':
1752 		spec->base = 16;
1753 		break;
1754 
1755 	case 'd':
1756 	case 'i':
1757 		spec->flags |= SIGN;
1758 	case 'u':
1759 		break;
1760 
1761 	case 'n':
1762 		/*
1763 		 * Since %n poses a greater security risk than utility, treat
1764 		 * it as an invalid format specifier. Warn about its use so
1765 		 * that new instances don't get added.
1766 		 */
1767 		WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1768 		/* Fall-through */
1769 
1770 	default:
1771 		spec->type = FORMAT_TYPE_INVALID;
1772 		return fmt - start;
1773 	}
1774 
1775 	if (spec->qualifier == 'L')
1776 		spec->type = FORMAT_TYPE_LONG_LONG;
1777 	else if (spec->qualifier == 'l') {
1778 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
1779 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
1780 	} else if (_tolower(spec->qualifier) == 'z') {
1781 		spec->type = FORMAT_TYPE_SIZE_T;
1782 	} else if (spec->qualifier == 't') {
1783 		spec->type = FORMAT_TYPE_PTRDIFF;
1784 	} else if (spec->qualifier == 'H') {
1785 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
1786 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
1787 	} else if (spec->qualifier == 'h') {
1788 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
1789 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
1790 	} else {
1791 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
1792 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
1793 	}
1794 
1795 	return ++fmt - start;
1796 }
1797 
1798 /**
1799  * vsnprintf - Format a string and place it in a buffer
1800  * @buf: The buffer to place the result into
1801  * @size: The size of the buffer, including the trailing null space
1802  * @fmt: The format string to use
1803  * @args: Arguments for the format string
1804  *
1805  * This function follows C99 vsnprintf, but has some extensions:
1806  * %pS output the name of a text symbol with offset
1807  * %ps output the name of a text symbol without offset
1808  * %pF output the name of a function pointer with its offset
1809  * %pf output the name of a function pointer without its offset
1810  * %pB output the name of a backtrace symbol with its offset
1811  * %pR output the address range in a struct resource with decoded flags
1812  * %pr output the address range in a struct resource with raw flags
1813  * %pb output the bitmap with field width as the number of bits
1814  * %pbl output the bitmap as range list with field width as the number of bits
1815  * %pM output a 6-byte MAC address with colons
1816  * %pMR output a 6-byte MAC address with colons in reversed order
1817  * %pMF output a 6-byte MAC address with dashes
1818  * %pm output a 6-byte MAC address without colons
1819  * %pmR output a 6-byte MAC address without colons in reversed order
1820  * %pI4 print an IPv4 address without leading zeros
1821  * %pi4 print an IPv4 address with leading zeros
1822  * %pI6 print an IPv6 address with colons
1823  * %pi6 print an IPv6 address without colons
1824  * %pI6c print an IPv6 address as specified by RFC 5952
1825  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1826  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1827  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1828  *   case.
1829  * %*pE[achnops] print an escaped buffer
1830  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1831  *           bytes of the input)
1832  * %pC output the name (Common Clock Framework) or address (legacy clock
1833  *     framework) of a clock
1834  * %pCn output the name (Common Clock Framework) or address (legacy clock
1835  *      framework) of a clock
1836  * %pCr output the current rate of a clock
1837  * %n is ignored
1838  *
1839  * ** Please update Documentation/printk-formats.txt when making changes **
1840  *
1841  * The return value is the number of characters which would
1842  * be generated for the given input, excluding the trailing
1843  * '\0', as per ISO C99. If you want to have the exact
1844  * number of characters written into @buf as return value
1845  * (not including the trailing '\0'), use vscnprintf(). If the
1846  * return is greater than or equal to @size, the resulting
1847  * string is truncated.
1848  *
1849  * If you're not already dealing with a va_list consider using snprintf().
1850  */
1851 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1852 {
1853 	unsigned long long num;
1854 	char *str, *end;
1855 	struct printf_spec spec = {0};
1856 
1857 	/* Reject out-of-range values early.  Large positive sizes are
1858 	   used for unknown buffer sizes. */
1859 	if (WARN_ON_ONCE(size > INT_MAX))
1860 		return 0;
1861 
1862 	str = buf;
1863 	end = buf + size;
1864 
1865 	/* Make sure end is always >= buf */
1866 	if (end < buf) {
1867 		end = ((void *)-1);
1868 		size = end - buf;
1869 	}
1870 
1871 	while (*fmt) {
1872 		const char *old_fmt = fmt;
1873 		int read = format_decode(fmt, &spec);
1874 
1875 		fmt += read;
1876 
1877 		switch (spec.type) {
1878 		case FORMAT_TYPE_NONE: {
1879 			int copy = read;
1880 			if (str < end) {
1881 				if (copy > end - str)
1882 					copy = end - str;
1883 				memcpy(str, old_fmt, copy);
1884 			}
1885 			str += read;
1886 			break;
1887 		}
1888 
1889 		case FORMAT_TYPE_WIDTH:
1890 			spec.field_width = va_arg(args, int);
1891 			break;
1892 
1893 		case FORMAT_TYPE_PRECISION:
1894 			spec.precision = va_arg(args, int);
1895 			break;
1896 
1897 		case FORMAT_TYPE_CHAR: {
1898 			char c;
1899 
1900 			if (!(spec.flags & LEFT)) {
1901 				while (--spec.field_width > 0) {
1902 					if (str < end)
1903 						*str = ' ';
1904 					++str;
1905 
1906 				}
1907 			}
1908 			c = (unsigned char) va_arg(args, int);
1909 			if (str < end)
1910 				*str = c;
1911 			++str;
1912 			while (--spec.field_width > 0) {
1913 				if (str < end)
1914 					*str = ' ';
1915 				++str;
1916 			}
1917 			break;
1918 		}
1919 
1920 		case FORMAT_TYPE_STR:
1921 			str = string(str, end, va_arg(args, char *), spec);
1922 			break;
1923 
1924 		case FORMAT_TYPE_PTR:
1925 			str = pointer(fmt, str, end, va_arg(args, void *),
1926 				      spec);
1927 			while (isalnum(*fmt))
1928 				fmt++;
1929 			break;
1930 
1931 		case FORMAT_TYPE_PERCENT_CHAR:
1932 			if (str < end)
1933 				*str = '%';
1934 			++str;
1935 			break;
1936 
1937 		case FORMAT_TYPE_INVALID:
1938 			if (str < end)
1939 				*str = '%';
1940 			++str;
1941 			break;
1942 
1943 		default:
1944 			switch (spec.type) {
1945 			case FORMAT_TYPE_LONG_LONG:
1946 				num = va_arg(args, long long);
1947 				break;
1948 			case FORMAT_TYPE_ULONG:
1949 				num = va_arg(args, unsigned long);
1950 				break;
1951 			case FORMAT_TYPE_LONG:
1952 				num = va_arg(args, long);
1953 				break;
1954 			case FORMAT_TYPE_SIZE_T:
1955 				if (spec.flags & SIGN)
1956 					num = va_arg(args, ssize_t);
1957 				else
1958 					num = va_arg(args, size_t);
1959 				break;
1960 			case FORMAT_TYPE_PTRDIFF:
1961 				num = va_arg(args, ptrdiff_t);
1962 				break;
1963 			case FORMAT_TYPE_UBYTE:
1964 				num = (unsigned char) va_arg(args, int);
1965 				break;
1966 			case FORMAT_TYPE_BYTE:
1967 				num = (signed char) va_arg(args, int);
1968 				break;
1969 			case FORMAT_TYPE_USHORT:
1970 				num = (unsigned short) va_arg(args, int);
1971 				break;
1972 			case FORMAT_TYPE_SHORT:
1973 				num = (short) va_arg(args, int);
1974 				break;
1975 			case FORMAT_TYPE_INT:
1976 				num = (int) va_arg(args, int);
1977 				break;
1978 			default:
1979 				num = va_arg(args, unsigned int);
1980 			}
1981 
1982 			str = number(str, end, num, spec);
1983 		}
1984 	}
1985 
1986 	if (size > 0) {
1987 		if (str < end)
1988 			*str = '\0';
1989 		else
1990 			end[-1] = '\0';
1991 	}
1992 
1993 	/* the trailing null byte doesn't count towards the total */
1994 	return str-buf;
1995 
1996 }
1997 EXPORT_SYMBOL(vsnprintf);
1998 
1999 /**
2000  * vscnprintf - Format a string and place it in a buffer
2001  * @buf: The buffer to place the result into
2002  * @size: The size of the buffer, including the trailing null space
2003  * @fmt: The format string to use
2004  * @args: Arguments for the format string
2005  *
2006  * The return value is the number of characters which have been written into
2007  * the @buf not including the trailing '\0'. If @size is == 0 the function
2008  * returns 0.
2009  *
2010  * If you're not already dealing with a va_list consider using scnprintf().
2011  *
2012  * See the vsnprintf() documentation for format string extensions over C99.
2013  */
2014 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2015 {
2016 	int i;
2017 
2018 	i = vsnprintf(buf, size, fmt, args);
2019 
2020 	if (likely(i < size))
2021 		return i;
2022 	if (size != 0)
2023 		return size - 1;
2024 	return 0;
2025 }
2026 EXPORT_SYMBOL(vscnprintf);
2027 
2028 /**
2029  * snprintf - Format a string and place it in a buffer
2030  * @buf: The buffer to place the result into
2031  * @size: The size of the buffer, including the trailing null space
2032  * @fmt: The format string to use
2033  * @...: Arguments for the format string
2034  *
2035  * The return value is the number of characters which would be
2036  * generated for the given input, excluding the trailing null,
2037  * as per ISO C99.  If the return is greater than or equal to
2038  * @size, the resulting string is truncated.
2039  *
2040  * See the vsnprintf() documentation for format string extensions over C99.
2041  */
2042 int snprintf(char *buf, size_t size, const char *fmt, ...)
2043 {
2044 	va_list args;
2045 	int i;
2046 
2047 	va_start(args, fmt);
2048 	i = vsnprintf(buf, size, fmt, args);
2049 	va_end(args);
2050 
2051 	return i;
2052 }
2053 EXPORT_SYMBOL(snprintf);
2054 
2055 /**
2056  * scnprintf - Format a string and place it in a buffer
2057  * @buf: The buffer to place the result into
2058  * @size: The size of the buffer, including the trailing null space
2059  * @fmt: The format string to use
2060  * @...: Arguments for the format string
2061  *
2062  * The return value is the number of characters written into @buf not including
2063  * the trailing '\0'. If @size is == 0 the function returns 0.
2064  */
2065 
2066 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2067 {
2068 	va_list args;
2069 	int i;
2070 
2071 	va_start(args, fmt);
2072 	i = vscnprintf(buf, size, fmt, args);
2073 	va_end(args);
2074 
2075 	return i;
2076 }
2077 EXPORT_SYMBOL(scnprintf);
2078 
2079 /**
2080  * vsprintf - Format a string and place it in a buffer
2081  * @buf: The buffer to place the result into
2082  * @fmt: The format string to use
2083  * @args: Arguments for the format string
2084  *
2085  * The function returns the number of characters written
2086  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2087  * buffer overflows.
2088  *
2089  * If you're not already dealing with a va_list consider using sprintf().
2090  *
2091  * See the vsnprintf() documentation for format string extensions over C99.
2092  */
2093 int vsprintf(char *buf, const char *fmt, va_list args)
2094 {
2095 	return vsnprintf(buf, INT_MAX, fmt, args);
2096 }
2097 EXPORT_SYMBOL(vsprintf);
2098 
2099 /**
2100  * sprintf - Format a string and place it in a buffer
2101  * @buf: The buffer to place the result into
2102  * @fmt: The format string to use
2103  * @...: Arguments for the format string
2104  *
2105  * The function returns the number of characters written
2106  * into @buf. Use snprintf() or scnprintf() in order to avoid
2107  * buffer overflows.
2108  *
2109  * See the vsnprintf() documentation for format string extensions over C99.
2110  */
2111 int sprintf(char *buf, const char *fmt, ...)
2112 {
2113 	va_list args;
2114 	int i;
2115 
2116 	va_start(args, fmt);
2117 	i = vsnprintf(buf, INT_MAX, fmt, args);
2118 	va_end(args);
2119 
2120 	return i;
2121 }
2122 EXPORT_SYMBOL(sprintf);
2123 
2124 #ifdef CONFIG_BINARY_PRINTF
2125 /*
2126  * bprintf service:
2127  * vbin_printf() - VA arguments to binary data
2128  * bstr_printf() - Binary data to text string
2129  */
2130 
2131 /**
2132  * vbin_printf - Parse a format string and place args' binary value in a buffer
2133  * @bin_buf: The buffer to place args' binary value
2134  * @size: The size of the buffer(by words(32bits), not characters)
2135  * @fmt: The format string to use
2136  * @args: Arguments for the format string
2137  *
2138  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2139  * is skipped.
2140  *
2141  * The return value is the number of words(32bits) which would be generated for
2142  * the given input.
2143  *
2144  * NOTE:
2145  * If the return value is greater than @size, the resulting bin_buf is NOT
2146  * valid for bstr_printf().
2147  */
2148 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2149 {
2150 	struct printf_spec spec = {0};
2151 	char *str, *end;
2152 
2153 	str = (char *)bin_buf;
2154 	end = (char *)(bin_buf + size);
2155 
2156 #define save_arg(type)							\
2157 do {									\
2158 	if (sizeof(type) == 8) {					\
2159 		unsigned long long value;				\
2160 		str = PTR_ALIGN(str, sizeof(u32));			\
2161 		value = va_arg(args, unsigned long long);		\
2162 		if (str + sizeof(type) <= end) {			\
2163 			*(u32 *)str = *(u32 *)&value;			\
2164 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
2165 		}							\
2166 	} else {							\
2167 		unsigned long value;					\
2168 		str = PTR_ALIGN(str, sizeof(type));			\
2169 		value = va_arg(args, int);				\
2170 		if (str + sizeof(type) <= end)				\
2171 			*(typeof(type) *)str = (type)value;		\
2172 	}								\
2173 	str += sizeof(type);						\
2174 } while (0)
2175 
2176 	while (*fmt) {
2177 		int read = format_decode(fmt, &spec);
2178 
2179 		fmt += read;
2180 
2181 		switch (spec.type) {
2182 		case FORMAT_TYPE_NONE:
2183 		case FORMAT_TYPE_INVALID:
2184 		case FORMAT_TYPE_PERCENT_CHAR:
2185 			break;
2186 
2187 		case FORMAT_TYPE_WIDTH:
2188 		case FORMAT_TYPE_PRECISION:
2189 			save_arg(int);
2190 			break;
2191 
2192 		case FORMAT_TYPE_CHAR:
2193 			save_arg(char);
2194 			break;
2195 
2196 		case FORMAT_TYPE_STR: {
2197 			const char *save_str = va_arg(args, char *);
2198 			size_t len;
2199 
2200 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2201 					|| (unsigned long)save_str < PAGE_SIZE)
2202 				save_str = "(null)";
2203 			len = strlen(save_str) + 1;
2204 			if (str + len < end)
2205 				memcpy(str, save_str, len);
2206 			str += len;
2207 			break;
2208 		}
2209 
2210 		case FORMAT_TYPE_PTR:
2211 			save_arg(void *);
2212 			/* skip all alphanumeric pointer suffixes */
2213 			while (isalnum(*fmt))
2214 				fmt++;
2215 			break;
2216 
2217 		default:
2218 			switch (spec.type) {
2219 
2220 			case FORMAT_TYPE_LONG_LONG:
2221 				save_arg(long long);
2222 				break;
2223 			case FORMAT_TYPE_ULONG:
2224 			case FORMAT_TYPE_LONG:
2225 				save_arg(unsigned long);
2226 				break;
2227 			case FORMAT_TYPE_SIZE_T:
2228 				save_arg(size_t);
2229 				break;
2230 			case FORMAT_TYPE_PTRDIFF:
2231 				save_arg(ptrdiff_t);
2232 				break;
2233 			case FORMAT_TYPE_UBYTE:
2234 			case FORMAT_TYPE_BYTE:
2235 				save_arg(char);
2236 				break;
2237 			case FORMAT_TYPE_USHORT:
2238 			case FORMAT_TYPE_SHORT:
2239 				save_arg(short);
2240 				break;
2241 			default:
2242 				save_arg(int);
2243 			}
2244 		}
2245 	}
2246 
2247 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2248 #undef save_arg
2249 }
2250 EXPORT_SYMBOL_GPL(vbin_printf);
2251 
2252 /**
2253  * bstr_printf - Format a string from binary arguments and place it in a buffer
2254  * @buf: The buffer to place the result into
2255  * @size: The size of the buffer, including the trailing null space
2256  * @fmt: The format string to use
2257  * @bin_buf: Binary arguments for the format string
2258  *
2259  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2260  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2261  * a binary buffer that generated by vbin_printf.
2262  *
2263  * The format follows C99 vsnprintf, but has some extensions:
2264  *  see vsnprintf comment for details.
2265  *
2266  * The return value is the number of characters which would
2267  * be generated for the given input, excluding the trailing
2268  * '\0', as per ISO C99. If you want to have the exact
2269  * number of characters written into @buf as return value
2270  * (not including the trailing '\0'), use vscnprintf(). If the
2271  * return is greater than or equal to @size, the resulting
2272  * string is truncated.
2273  */
2274 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2275 {
2276 	struct printf_spec spec = {0};
2277 	char *str, *end;
2278 	const char *args = (const char *)bin_buf;
2279 
2280 	if (WARN_ON_ONCE((int) size < 0))
2281 		return 0;
2282 
2283 	str = buf;
2284 	end = buf + size;
2285 
2286 #define get_arg(type)							\
2287 ({									\
2288 	typeof(type) value;						\
2289 	if (sizeof(type) == 8) {					\
2290 		args = PTR_ALIGN(args, sizeof(u32));			\
2291 		*(u32 *)&value = *(u32 *)args;				\
2292 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2293 	} else {							\
2294 		args = PTR_ALIGN(args, sizeof(type));			\
2295 		value = *(typeof(type) *)args;				\
2296 	}								\
2297 	args += sizeof(type);						\
2298 	value;								\
2299 })
2300 
2301 	/* Make sure end is always >= buf */
2302 	if (end < buf) {
2303 		end = ((void *)-1);
2304 		size = end - buf;
2305 	}
2306 
2307 	while (*fmt) {
2308 		const char *old_fmt = fmt;
2309 		int read = format_decode(fmt, &spec);
2310 
2311 		fmt += read;
2312 
2313 		switch (spec.type) {
2314 		case FORMAT_TYPE_NONE: {
2315 			int copy = read;
2316 			if (str < end) {
2317 				if (copy > end - str)
2318 					copy = end - str;
2319 				memcpy(str, old_fmt, copy);
2320 			}
2321 			str += read;
2322 			break;
2323 		}
2324 
2325 		case FORMAT_TYPE_WIDTH:
2326 			spec.field_width = get_arg(int);
2327 			break;
2328 
2329 		case FORMAT_TYPE_PRECISION:
2330 			spec.precision = get_arg(int);
2331 			break;
2332 
2333 		case FORMAT_TYPE_CHAR: {
2334 			char c;
2335 
2336 			if (!(spec.flags & LEFT)) {
2337 				while (--spec.field_width > 0) {
2338 					if (str < end)
2339 						*str = ' ';
2340 					++str;
2341 				}
2342 			}
2343 			c = (unsigned char) get_arg(char);
2344 			if (str < end)
2345 				*str = c;
2346 			++str;
2347 			while (--spec.field_width > 0) {
2348 				if (str < end)
2349 					*str = ' ';
2350 				++str;
2351 			}
2352 			break;
2353 		}
2354 
2355 		case FORMAT_TYPE_STR: {
2356 			const char *str_arg = args;
2357 			args += strlen(str_arg) + 1;
2358 			str = string(str, end, (char *)str_arg, spec);
2359 			break;
2360 		}
2361 
2362 		case FORMAT_TYPE_PTR:
2363 			str = pointer(fmt, str, end, get_arg(void *), spec);
2364 			while (isalnum(*fmt))
2365 				fmt++;
2366 			break;
2367 
2368 		case FORMAT_TYPE_PERCENT_CHAR:
2369 		case FORMAT_TYPE_INVALID:
2370 			if (str < end)
2371 				*str = '%';
2372 			++str;
2373 			break;
2374 
2375 		default: {
2376 			unsigned long long num;
2377 
2378 			switch (spec.type) {
2379 
2380 			case FORMAT_TYPE_LONG_LONG:
2381 				num = get_arg(long long);
2382 				break;
2383 			case FORMAT_TYPE_ULONG:
2384 			case FORMAT_TYPE_LONG:
2385 				num = get_arg(unsigned long);
2386 				break;
2387 			case FORMAT_TYPE_SIZE_T:
2388 				num = get_arg(size_t);
2389 				break;
2390 			case FORMAT_TYPE_PTRDIFF:
2391 				num = get_arg(ptrdiff_t);
2392 				break;
2393 			case FORMAT_TYPE_UBYTE:
2394 				num = get_arg(unsigned char);
2395 				break;
2396 			case FORMAT_TYPE_BYTE:
2397 				num = get_arg(signed char);
2398 				break;
2399 			case FORMAT_TYPE_USHORT:
2400 				num = get_arg(unsigned short);
2401 				break;
2402 			case FORMAT_TYPE_SHORT:
2403 				num = get_arg(short);
2404 				break;
2405 			case FORMAT_TYPE_UINT:
2406 				num = get_arg(unsigned int);
2407 				break;
2408 			default:
2409 				num = get_arg(int);
2410 			}
2411 
2412 			str = number(str, end, num, spec);
2413 		} /* default: */
2414 		} /* switch(spec.type) */
2415 	} /* while(*fmt) */
2416 
2417 	if (size > 0) {
2418 		if (str < end)
2419 			*str = '\0';
2420 		else
2421 			end[-1] = '\0';
2422 	}
2423 
2424 #undef get_arg
2425 
2426 	/* the trailing null byte doesn't count towards the total */
2427 	return str - buf;
2428 }
2429 EXPORT_SYMBOL_GPL(bstr_printf);
2430 
2431 /**
2432  * bprintf - Parse a format string and place args' binary value in a buffer
2433  * @bin_buf: The buffer to place args' binary value
2434  * @size: The size of the buffer(by words(32bits), not characters)
2435  * @fmt: The format string to use
2436  * @...: Arguments for the format string
2437  *
2438  * The function returns the number of words(u32) written
2439  * into @bin_buf.
2440  */
2441 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2442 {
2443 	va_list args;
2444 	int ret;
2445 
2446 	va_start(args, fmt);
2447 	ret = vbin_printf(bin_buf, size, fmt, args);
2448 	va_end(args);
2449 
2450 	return ret;
2451 }
2452 EXPORT_SYMBOL_GPL(bprintf);
2453 
2454 #endif /* CONFIG_BINARY_PRINTF */
2455 
2456 /**
2457  * vsscanf - Unformat a buffer into a list of arguments
2458  * @buf:	input buffer
2459  * @fmt:	format of buffer
2460  * @args:	arguments
2461  */
2462 int vsscanf(const char *buf, const char *fmt, va_list args)
2463 {
2464 	const char *str = buf;
2465 	char *next;
2466 	char digit;
2467 	int num = 0;
2468 	u8 qualifier;
2469 	unsigned int base;
2470 	union {
2471 		long long s;
2472 		unsigned long long u;
2473 	} val;
2474 	s16 field_width;
2475 	bool is_sign;
2476 
2477 	while (*fmt) {
2478 		/* skip any white space in format */
2479 		/* white space in format matchs any amount of
2480 		 * white space, including none, in the input.
2481 		 */
2482 		if (isspace(*fmt)) {
2483 			fmt = skip_spaces(++fmt);
2484 			str = skip_spaces(str);
2485 		}
2486 
2487 		/* anything that is not a conversion must match exactly */
2488 		if (*fmt != '%' && *fmt) {
2489 			if (*fmt++ != *str++)
2490 				break;
2491 			continue;
2492 		}
2493 
2494 		if (!*fmt)
2495 			break;
2496 		++fmt;
2497 
2498 		/* skip this conversion.
2499 		 * advance both strings to next white space
2500 		 */
2501 		if (*fmt == '*') {
2502 			if (!*str)
2503 				break;
2504 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
2505 				fmt++;
2506 			while (!isspace(*str) && *str)
2507 				str++;
2508 			continue;
2509 		}
2510 
2511 		/* get field width */
2512 		field_width = -1;
2513 		if (isdigit(*fmt)) {
2514 			field_width = skip_atoi(&fmt);
2515 			if (field_width <= 0)
2516 				break;
2517 		}
2518 
2519 		/* get conversion qualifier */
2520 		qualifier = -1;
2521 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2522 		    _tolower(*fmt) == 'z') {
2523 			qualifier = *fmt++;
2524 			if (unlikely(qualifier == *fmt)) {
2525 				if (qualifier == 'h') {
2526 					qualifier = 'H';
2527 					fmt++;
2528 				} else if (qualifier == 'l') {
2529 					qualifier = 'L';
2530 					fmt++;
2531 				}
2532 			}
2533 		}
2534 
2535 		if (!*fmt)
2536 			break;
2537 
2538 		if (*fmt == 'n') {
2539 			/* return number of characters read so far */
2540 			*va_arg(args, int *) = str - buf;
2541 			++fmt;
2542 			continue;
2543 		}
2544 
2545 		if (!*str)
2546 			break;
2547 
2548 		base = 10;
2549 		is_sign = false;
2550 
2551 		switch (*fmt++) {
2552 		case 'c':
2553 		{
2554 			char *s = (char *)va_arg(args, char*);
2555 			if (field_width == -1)
2556 				field_width = 1;
2557 			do {
2558 				*s++ = *str++;
2559 			} while (--field_width > 0 && *str);
2560 			num++;
2561 		}
2562 		continue;
2563 		case 's':
2564 		{
2565 			char *s = (char *)va_arg(args, char *);
2566 			if (field_width == -1)
2567 				field_width = SHRT_MAX;
2568 			/* first, skip leading white space in buffer */
2569 			str = skip_spaces(str);
2570 
2571 			/* now copy until next white space */
2572 			while (*str && !isspace(*str) && field_width--)
2573 				*s++ = *str++;
2574 			*s = '\0';
2575 			num++;
2576 		}
2577 		continue;
2578 		case 'o':
2579 			base = 8;
2580 			break;
2581 		case 'x':
2582 		case 'X':
2583 			base = 16;
2584 			break;
2585 		case 'i':
2586 			base = 0;
2587 		case 'd':
2588 			is_sign = true;
2589 		case 'u':
2590 			break;
2591 		case '%':
2592 			/* looking for '%' in str */
2593 			if (*str++ != '%')
2594 				return num;
2595 			continue;
2596 		default:
2597 			/* invalid format; stop here */
2598 			return num;
2599 		}
2600 
2601 		/* have some sort of integer conversion.
2602 		 * first, skip white space in buffer.
2603 		 */
2604 		str = skip_spaces(str);
2605 
2606 		digit = *str;
2607 		if (is_sign && digit == '-')
2608 			digit = *(str + 1);
2609 
2610 		if (!digit
2611 		    || (base == 16 && !isxdigit(digit))
2612 		    || (base == 10 && !isdigit(digit))
2613 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
2614 		    || (base == 0 && !isdigit(digit)))
2615 			break;
2616 
2617 		if (is_sign)
2618 			val.s = qualifier != 'L' ?
2619 				simple_strtol(str, &next, base) :
2620 				simple_strtoll(str, &next, base);
2621 		else
2622 			val.u = qualifier != 'L' ?
2623 				simple_strtoul(str, &next, base) :
2624 				simple_strtoull(str, &next, base);
2625 
2626 		if (field_width > 0 && next - str > field_width) {
2627 			if (base == 0)
2628 				_parse_integer_fixup_radix(str, &base);
2629 			while (next - str > field_width) {
2630 				if (is_sign)
2631 					val.s = div_s64(val.s, base);
2632 				else
2633 					val.u = div_u64(val.u, base);
2634 				--next;
2635 			}
2636 		}
2637 
2638 		switch (qualifier) {
2639 		case 'H':	/* that's 'hh' in format */
2640 			if (is_sign)
2641 				*va_arg(args, signed char *) = val.s;
2642 			else
2643 				*va_arg(args, unsigned char *) = val.u;
2644 			break;
2645 		case 'h':
2646 			if (is_sign)
2647 				*va_arg(args, short *) = val.s;
2648 			else
2649 				*va_arg(args, unsigned short *) = val.u;
2650 			break;
2651 		case 'l':
2652 			if (is_sign)
2653 				*va_arg(args, long *) = val.s;
2654 			else
2655 				*va_arg(args, unsigned long *) = val.u;
2656 			break;
2657 		case 'L':
2658 			if (is_sign)
2659 				*va_arg(args, long long *) = val.s;
2660 			else
2661 				*va_arg(args, unsigned long long *) = val.u;
2662 			break;
2663 		case 'Z':
2664 		case 'z':
2665 			*va_arg(args, size_t *) = val.u;
2666 			break;
2667 		default:
2668 			if (is_sign)
2669 				*va_arg(args, int *) = val.s;
2670 			else
2671 				*va_arg(args, unsigned int *) = val.u;
2672 			break;
2673 		}
2674 		num++;
2675 
2676 		if (!next)
2677 			break;
2678 		str = next;
2679 	}
2680 
2681 	return num;
2682 }
2683 EXPORT_SYMBOL(vsscanf);
2684 
2685 /**
2686  * sscanf - Unformat a buffer into a list of arguments
2687  * @buf:	input buffer
2688  * @fmt:	formatting of buffer
2689  * @...:	resulting arguments
2690  */
2691 int sscanf(const char *buf, const char *fmt, ...)
2692 {
2693 	va_list args;
2694 	int i;
2695 
2696 	va_start(args, fmt);
2697 	i = vsscanf(buf, fmt, args);
2698 	va_end(args);
2699 
2700 	return i;
2701 }
2702 EXPORT_SYMBOL(sscanf);
2703