xref: /openbmc/linux/lib/vsprintf.c (revision 132db935)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/lib/vsprintf.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  */
7 
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10  * Wirzenius wrote this portably, Torvalds fucked it up :-)
11  */
12 
13 /*
14  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15  * - changed to provide snprintf and vsnprintf functions
16  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17  * - scnprintf and vscnprintf
18  */
19 
20 #include <stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/time.h>
38 #include <linux/uuid.h>
39 #include <linux/of.h>
40 #include <net/addrconf.h>
41 #include <linux/siphash.h>
42 #include <linux/compiler.h>
43 #include <linux/property.h>
44 #ifdef CONFIG_BLOCK
45 #include <linux/blkdev.h>
46 #endif
47 
48 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
49 
50 #include <asm/page.h>		/* for PAGE_SIZE */
51 #include <asm/byteorder.h>	/* cpu_to_le16 */
52 
53 #include <linux/string_helpers.h>
54 #include "kstrtox.h"
55 
56 /**
57  * simple_strtoull - convert a string to an unsigned long long
58  * @cp: The start of the string
59  * @endp: A pointer to the end of the parsed string will be placed here
60  * @base: The number base to use
61  *
62  * This function has caveats. Please use kstrtoull instead.
63  */
64 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
65 {
66 	unsigned long long result;
67 	unsigned int rv;
68 
69 	cp = _parse_integer_fixup_radix(cp, &base);
70 	rv = _parse_integer(cp, base, &result);
71 	/* FIXME */
72 	cp += (rv & ~KSTRTOX_OVERFLOW);
73 
74 	if (endp)
75 		*endp = (char *)cp;
76 
77 	return result;
78 }
79 EXPORT_SYMBOL(simple_strtoull);
80 
81 /**
82  * simple_strtoul - convert a string to an unsigned long
83  * @cp: The start of the string
84  * @endp: A pointer to the end of the parsed string will be placed here
85  * @base: The number base to use
86  *
87  * This function has caveats. Please use kstrtoul instead.
88  */
89 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
90 {
91 	return simple_strtoull(cp, endp, base);
92 }
93 EXPORT_SYMBOL(simple_strtoul);
94 
95 /**
96  * simple_strtol - convert a string to a signed 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 has caveats. Please use kstrtol instead.
102  */
103 long simple_strtol(const char *cp, char **endp, unsigned int base)
104 {
105 	if (*cp == '-')
106 		return -simple_strtoul(cp + 1, endp, base);
107 
108 	return simple_strtoul(cp, endp, base);
109 }
110 EXPORT_SYMBOL(simple_strtol);
111 
112 /**
113  * simple_strtoll - convert a string to a signed long long
114  * @cp: The start of the string
115  * @endp: A pointer to the end of the parsed string will be placed here
116  * @base: The number base to use
117  *
118  * This function has caveats. Please use kstrtoll instead.
119  */
120 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
121 {
122 	if (*cp == '-')
123 		return -simple_strtoull(cp + 1, endp, base);
124 
125 	return simple_strtoull(cp, endp, base);
126 }
127 EXPORT_SYMBOL(simple_strtoll);
128 
129 static noinline_for_stack
130 int skip_atoi(const char **s)
131 {
132 	int i = 0;
133 
134 	do {
135 		i = i*10 + *((*s)++) - '0';
136 	} while (isdigit(**s));
137 
138 	return i;
139 }
140 
141 /*
142  * Decimal conversion is by far the most typical, and is used for
143  * /proc and /sys data. This directly impacts e.g. top performance
144  * with many processes running. We optimize it for speed by emitting
145  * two characters at a time, using a 200 byte lookup table. This
146  * roughly halves the number of multiplications compared to computing
147  * the digits one at a time. Implementation strongly inspired by the
148  * previous version, which in turn used ideas described at
149  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
150  * from the author, Douglas W. Jones).
151  *
152  * It turns out there is precisely one 26 bit fixed-point
153  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
154  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
155  * range happens to be somewhat larger (x <= 1073741898), but that's
156  * irrelevant for our purpose.
157  *
158  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
159  * need a 32x32->64 bit multiply, so we simply use the same constant.
160  *
161  * For dividing a number in the range [100, 10^4-1] by 100, there are
162  * several options. The simplest is (x * 0x147b) >> 19, which is valid
163  * for all x <= 43698.
164  */
165 
166 static const u16 decpair[100] = {
167 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
168 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
169 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
170 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
171 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
172 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
173 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
174 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
175 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
176 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
177 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
178 #undef _
179 };
180 
181 /*
182  * This will print a single '0' even if r == 0, since we would
183  * immediately jump to out_r where two 0s would be written but only
184  * one of them accounted for in buf. This is needed by ip4_string
185  * below. All other callers pass a non-zero value of r.
186 */
187 static noinline_for_stack
188 char *put_dec_trunc8(char *buf, unsigned r)
189 {
190 	unsigned q;
191 
192 	/* 1 <= r < 10^8 */
193 	if (r < 100)
194 		goto out_r;
195 
196 	/* 100 <= r < 10^8 */
197 	q = (r * (u64)0x28f5c29) >> 32;
198 	*((u16 *)buf) = decpair[r - 100*q];
199 	buf += 2;
200 
201 	/* 1 <= q < 10^6 */
202 	if (q < 100)
203 		goto out_q;
204 
205 	/*  100 <= q < 10^6 */
206 	r = (q * (u64)0x28f5c29) >> 32;
207 	*((u16 *)buf) = decpair[q - 100*r];
208 	buf += 2;
209 
210 	/* 1 <= r < 10^4 */
211 	if (r < 100)
212 		goto out_r;
213 
214 	/* 100 <= r < 10^4 */
215 	q = (r * 0x147b) >> 19;
216 	*((u16 *)buf) = decpair[r - 100*q];
217 	buf += 2;
218 out_q:
219 	/* 1 <= q < 100 */
220 	r = q;
221 out_r:
222 	/* 1 <= r < 100 */
223 	*((u16 *)buf) = decpair[r];
224 	buf += r < 10 ? 1 : 2;
225 	return buf;
226 }
227 
228 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
229 static noinline_for_stack
230 char *put_dec_full8(char *buf, unsigned r)
231 {
232 	unsigned q;
233 
234 	/* 0 <= r < 10^8 */
235 	q = (r * (u64)0x28f5c29) >> 32;
236 	*((u16 *)buf) = decpair[r - 100*q];
237 	buf += 2;
238 
239 	/* 0 <= q < 10^6 */
240 	r = (q * (u64)0x28f5c29) >> 32;
241 	*((u16 *)buf) = decpair[q - 100*r];
242 	buf += 2;
243 
244 	/* 0 <= r < 10^4 */
245 	q = (r * 0x147b) >> 19;
246 	*((u16 *)buf) = decpair[r - 100*q];
247 	buf += 2;
248 
249 	/* 0 <= q < 100 */
250 	*((u16 *)buf) = decpair[q];
251 	buf += 2;
252 	return buf;
253 }
254 
255 static noinline_for_stack
256 char *put_dec(char *buf, unsigned long long n)
257 {
258 	if (n >= 100*1000*1000)
259 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
260 	/* 1 <= n <= 1.6e11 */
261 	if (n >= 100*1000*1000)
262 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
263 	/* 1 <= n < 1e8 */
264 	return put_dec_trunc8(buf, n);
265 }
266 
267 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
268 
269 static void
270 put_dec_full4(char *buf, unsigned r)
271 {
272 	unsigned q;
273 
274 	/* 0 <= r < 10^4 */
275 	q = (r * 0x147b) >> 19;
276 	*((u16 *)buf) = decpair[r - 100*q];
277 	buf += 2;
278 	/* 0 <= q < 100 */
279 	*((u16 *)buf) = decpair[q];
280 }
281 
282 /*
283  * Call put_dec_full4 on x % 10000, return x / 10000.
284  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
285  * holds for all x < 1,128,869,999.  The largest value this
286  * helper will ever be asked to convert is 1,125,520,955.
287  * (second call in the put_dec code, assuming n is all-ones).
288  */
289 static noinline_for_stack
290 unsigned put_dec_helper4(char *buf, unsigned x)
291 {
292         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
293 
294         put_dec_full4(buf, x - q * 10000);
295         return q;
296 }
297 
298 /* Based on code by Douglas W. Jones found at
299  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
300  * (with permission from the author).
301  * Performs no 64-bit division and hence should be fast on 32-bit machines.
302  */
303 static
304 char *put_dec(char *buf, unsigned long long n)
305 {
306 	uint32_t d3, d2, d1, q, h;
307 
308 	if (n < 100*1000*1000)
309 		return put_dec_trunc8(buf, n);
310 
311 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
312 	h   = (n >> 32);
313 	d2  = (h      ) & 0xffff;
314 	d3  = (h >> 16); /* implicit "& 0xffff" */
315 
316 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
317 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
318 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
319 	q = put_dec_helper4(buf, q);
320 
321 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
322 	q = put_dec_helper4(buf+4, q);
323 
324 	q += 4749 * d3 + 42 * d2;
325 	q = put_dec_helper4(buf+8, q);
326 
327 	q += 281 * d3;
328 	buf += 12;
329 	if (q)
330 		buf = put_dec_trunc8(buf, q);
331 	else while (buf[-1] == '0')
332 		--buf;
333 
334 	return buf;
335 }
336 
337 #endif
338 
339 /*
340  * Convert passed number to decimal string.
341  * Returns the length of string.  On buffer overflow, returns 0.
342  *
343  * If speed is not important, use snprintf(). It's easy to read the code.
344  */
345 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
346 {
347 	/* put_dec requires 2-byte alignment of the buffer. */
348 	char tmp[sizeof(num) * 3] __aligned(2);
349 	int idx, len;
350 
351 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
352 	if (num <= 9) {
353 		tmp[0] = '0' + num;
354 		len = 1;
355 	} else {
356 		len = put_dec(tmp, num) - tmp;
357 	}
358 
359 	if (len > size || width > size)
360 		return 0;
361 
362 	if (width > len) {
363 		width = width - len;
364 		for (idx = 0; idx < width; idx++)
365 			buf[idx] = ' ';
366 	} else {
367 		width = 0;
368 	}
369 
370 	for (idx = 0; idx < len; ++idx)
371 		buf[idx + width] = tmp[len - idx - 1];
372 
373 	return len + width;
374 }
375 
376 #define SIGN	1		/* unsigned/signed, must be 1 */
377 #define LEFT	2		/* left justified */
378 #define PLUS	4		/* show plus */
379 #define SPACE	8		/* space if plus */
380 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
381 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
382 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
383 
384 enum format_type {
385 	FORMAT_TYPE_NONE, /* Just a string part */
386 	FORMAT_TYPE_WIDTH,
387 	FORMAT_TYPE_PRECISION,
388 	FORMAT_TYPE_CHAR,
389 	FORMAT_TYPE_STR,
390 	FORMAT_TYPE_PTR,
391 	FORMAT_TYPE_PERCENT_CHAR,
392 	FORMAT_TYPE_INVALID,
393 	FORMAT_TYPE_LONG_LONG,
394 	FORMAT_TYPE_ULONG,
395 	FORMAT_TYPE_LONG,
396 	FORMAT_TYPE_UBYTE,
397 	FORMAT_TYPE_BYTE,
398 	FORMAT_TYPE_USHORT,
399 	FORMAT_TYPE_SHORT,
400 	FORMAT_TYPE_UINT,
401 	FORMAT_TYPE_INT,
402 	FORMAT_TYPE_SIZE_T,
403 	FORMAT_TYPE_PTRDIFF
404 };
405 
406 struct printf_spec {
407 	unsigned int	type:8;		/* format_type enum */
408 	signed int	field_width:24;	/* width of output field */
409 	unsigned int	flags:8;	/* flags to number() */
410 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
411 	signed int	precision:16;	/* # of digits/chars */
412 } __packed;
413 static_assert(sizeof(struct printf_spec) == 8);
414 
415 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
416 #define PRECISION_MAX ((1 << 15) - 1)
417 
418 static noinline_for_stack
419 char *number(char *buf, char *end, unsigned long long num,
420 	     struct printf_spec spec)
421 {
422 	/* put_dec requires 2-byte alignment of the buffer. */
423 	char tmp[3 * sizeof(num)] __aligned(2);
424 	char sign;
425 	char locase;
426 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
427 	int i;
428 	bool is_zero = num == 0LL;
429 	int field_width = spec.field_width;
430 	int precision = spec.precision;
431 
432 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
433 	 * produces same digits or (maybe lowercased) letters */
434 	locase = (spec.flags & SMALL);
435 	if (spec.flags & LEFT)
436 		spec.flags &= ~ZEROPAD;
437 	sign = 0;
438 	if (spec.flags & SIGN) {
439 		if ((signed long long)num < 0) {
440 			sign = '-';
441 			num = -(signed long long)num;
442 			field_width--;
443 		} else if (spec.flags & PLUS) {
444 			sign = '+';
445 			field_width--;
446 		} else if (spec.flags & SPACE) {
447 			sign = ' ';
448 			field_width--;
449 		}
450 	}
451 	if (need_pfx) {
452 		if (spec.base == 16)
453 			field_width -= 2;
454 		else if (!is_zero)
455 			field_width--;
456 	}
457 
458 	/* generate full string in tmp[], in reverse order */
459 	i = 0;
460 	if (num < spec.base)
461 		tmp[i++] = hex_asc_upper[num] | locase;
462 	else if (spec.base != 10) { /* 8 or 16 */
463 		int mask = spec.base - 1;
464 		int shift = 3;
465 
466 		if (spec.base == 16)
467 			shift = 4;
468 		do {
469 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
470 			num >>= shift;
471 		} while (num);
472 	} else { /* base 10 */
473 		i = put_dec(tmp, num) - tmp;
474 	}
475 
476 	/* printing 100 using %2d gives "100", not "00" */
477 	if (i > precision)
478 		precision = i;
479 	/* leading space padding */
480 	field_width -= precision;
481 	if (!(spec.flags & (ZEROPAD | LEFT))) {
482 		while (--field_width >= 0) {
483 			if (buf < end)
484 				*buf = ' ';
485 			++buf;
486 		}
487 	}
488 	/* sign */
489 	if (sign) {
490 		if (buf < end)
491 			*buf = sign;
492 		++buf;
493 	}
494 	/* "0x" / "0" prefix */
495 	if (need_pfx) {
496 		if (spec.base == 16 || !is_zero) {
497 			if (buf < end)
498 				*buf = '0';
499 			++buf;
500 		}
501 		if (spec.base == 16) {
502 			if (buf < end)
503 				*buf = ('X' | locase);
504 			++buf;
505 		}
506 	}
507 	/* zero or space padding */
508 	if (!(spec.flags & LEFT)) {
509 		char c = ' ' + (spec.flags & ZEROPAD);
510 		BUILD_BUG_ON(' ' + ZEROPAD != '0');
511 		while (--field_width >= 0) {
512 			if (buf < end)
513 				*buf = c;
514 			++buf;
515 		}
516 	}
517 	/* hmm even more zero padding? */
518 	while (i <= --precision) {
519 		if (buf < end)
520 			*buf = '0';
521 		++buf;
522 	}
523 	/* actual digits of result */
524 	while (--i >= 0) {
525 		if (buf < end)
526 			*buf = tmp[i];
527 		++buf;
528 	}
529 	/* trailing space padding */
530 	while (--field_width >= 0) {
531 		if (buf < end)
532 			*buf = ' ';
533 		++buf;
534 	}
535 
536 	return buf;
537 }
538 
539 static noinline_for_stack
540 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
541 {
542 	struct printf_spec spec;
543 
544 	spec.type = FORMAT_TYPE_PTR;
545 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
546 	spec.flags = SPECIAL | SMALL | ZEROPAD;
547 	spec.base = 16;
548 	spec.precision = -1;
549 
550 	return number(buf, end, num, spec);
551 }
552 
553 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
554 {
555 	size_t size;
556 	if (buf >= end)	/* nowhere to put anything */
557 		return;
558 	size = end - buf;
559 	if (size <= spaces) {
560 		memset(buf, ' ', size);
561 		return;
562 	}
563 	if (len) {
564 		if (len > size - spaces)
565 			len = size - spaces;
566 		memmove(buf + spaces, buf, len);
567 	}
568 	memset(buf, ' ', spaces);
569 }
570 
571 /*
572  * Handle field width padding for a string.
573  * @buf: current buffer position
574  * @n: length of string
575  * @end: end of output buffer
576  * @spec: for field width and flags
577  * Returns: new buffer position after padding.
578  */
579 static noinline_for_stack
580 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
581 {
582 	unsigned spaces;
583 
584 	if (likely(n >= spec.field_width))
585 		return buf;
586 	/* we want to pad the sucker */
587 	spaces = spec.field_width - n;
588 	if (!(spec.flags & LEFT)) {
589 		move_right(buf - n, end, n, spaces);
590 		return buf + spaces;
591 	}
592 	while (spaces--) {
593 		if (buf < end)
594 			*buf = ' ';
595 		++buf;
596 	}
597 	return buf;
598 }
599 
600 /* Handle string from a well known address. */
601 static char *string_nocheck(char *buf, char *end, const char *s,
602 			    struct printf_spec spec)
603 {
604 	int len = 0;
605 	int lim = spec.precision;
606 
607 	while (lim--) {
608 		char c = *s++;
609 		if (!c)
610 			break;
611 		if (buf < end)
612 			*buf = c;
613 		++buf;
614 		++len;
615 	}
616 	return widen_string(buf, len, end, spec);
617 }
618 
619 static char *err_ptr(char *buf, char *end, void *ptr,
620 		     struct printf_spec spec)
621 {
622 	int err = PTR_ERR(ptr);
623 	const char *sym = errname(err);
624 
625 	if (sym)
626 		return string_nocheck(buf, end, sym, spec);
627 
628 	/*
629 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
630 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
631 	 * printing it as its decimal representation.
632 	 */
633 	spec.flags |= SIGN;
634 	spec.base = 10;
635 	return number(buf, end, err, spec);
636 }
637 
638 /* Be careful: error messages must fit into the given buffer. */
639 static char *error_string(char *buf, char *end, const char *s,
640 			  struct printf_spec spec)
641 {
642 	/*
643 	 * Hard limit to avoid a completely insane messages. It actually
644 	 * works pretty well because most error messages are in
645 	 * the many pointer format modifiers.
646 	 */
647 	if (spec.precision == -1)
648 		spec.precision = 2 * sizeof(void *);
649 
650 	return string_nocheck(buf, end, s, spec);
651 }
652 
653 /*
654  * Do not call any complex external code here. Nested printk()/vsprintf()
655  * might cause infinite loops. Failures might break printk() and would
656  * be hard to debug.
657  */
658 static const char *check_pointer_msg(const void *ptr)
659 {
660 	if (!ptr)
661 		return "(null)";
662 
663 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
664 		return "(efault)";
665 
666 	return NULL;
667 }
668 
669 static int check_pointer(char **buf, char *end, const void *ptr,
670 			 struct printf_spec spec)
671 {
672 	const char *err_msg;
673 
674 	err_msg = check_pointer_msg(ptr);
675 	if (err_msg) {
676 		*buf = error_string(*buf, end, err_msg, spec);
677 		return -EFAULT;
678 	}
679 
680 	return 0;
681 }
682 
683 static noinline_for_stack
684 char *string(char *buf, char *end, const char *s,
685 	     struct printf_spec spec)
686 {
687 	if (check_pointer(&buf, end, s, spec))
688 		return buf;
689 
690 	return string_nocheck(buf, end, s, spec);
691 }
692 
693 static char *pointer_string(char *buf, char *end,
694 			    const void *ptr,
695 			    struct printf_spec spec)
696 {
697 	spec.base = 16;
698 	spec.flags |= SMALL;
699 	if (spec.field_width == -1) {
700 		spec.field_width = 2 * sizeof(ptr);
701 		spec.flags |= ZEROPAD;
702 	}
703 
704 	return number(buf, end, (unsigned long int)ptr, spec);
705 }
706 
707 /* Make pointers available for printing early in the boot sequence. */
708 static int debug_boot_weak_hash __ro_after_init;
709 
710 static int __init debug_boot_weak_hash_enable(char *str)
711 {
712 	debug_boot_weak_hash = 1;
713 	pr_info("debug_boot_weak_hash enabled\n");
714 	return 0;
715 }
716 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
717 
718 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
719 static siphash_key_t ptr_key __read_mostly;
720 
721 static void enable_ptr_key_workfn(struct work_struct *work)
722 {
723 	get_random_bytes(&ptr_key, sizeof(ptr_key));
724 	/* Needs to run from preemptible context */
725 	static_branch_disable(&not_filled_random_ptr_key);
726 }
727 
728 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
729 
730 static void fill_random_ptr_key(struct random_ready_callback *unused)
731 {
732 	/* This may be in an interrupt handler. */
733 	queue_work(system_unbound_wq, &enable_ptr_key_work);
734 }
735 
736 static struct random_ready_callback random_ready = {
737 	.func = fill_random_ptr_key
738 };
739 
740 static int __init initialize_ptr_random(void)
741 {
742 	int key_size = sizeof(ptr_key);
743 	int ret;
744 
745 	/* Use hw RNG if available. */
746 	if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
747 		static_branch_disable(&not_filled_random_ptr_key);
748 		return 0;
749 	}
750 
751 	ret = add_random_ready_callback(&random_ready);
752 	if (!ret) {
753 		return 0;
754 	} else if (ret == -EALREADY) {
755 		/* This is in preemptible context */
756 		enable_ptr_key_workfn(&enable_ptr_key_work);
757 		return 0;
758 	}
759 
760 	return ret;
761 }
762 early_initcall(initialize_ptr_random);
763 
764 /* Maps a pointer to a 32 bit unique identifier. */
765 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
766 {
767 	unsigned long hashval;
768 
769 	if (static_branch_unlikely(&not_filled_random_ptr_key))
770 		return -EAGAIN;
771 
772 #ifdef CONFIG_64BIT
773 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
774 	/*
775 	 * Mask off the first 32 bits, this makes explicit that we have
776 	 * modified the address (and 32 bits is plenty for a unique ID).
777 	 */
778 	hashval = hashval & 0xffffffff;
779 #else
780 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
781 #endif
782 	*hashval_out = hashval;
783 	return 0;
784 }
785 
786 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
787 {
788 	return __ptr_to_hashval(ptr, hashval_out);
789 }
790 
791 static char *ptr_to_id(char *buf, char *end, const void *ptr,
792 		       struct printf_spec spec)
793 {
794 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
795 	unsigned long hashval;
796 	int ret;
797 
798 	/*
799 	 * Print the real pointer value for NULL and error pointers,
800 	 * as they are not actual addresses.
801 	 */
802 	if (IS_ERR_OR_NULL(ptr))
803 		return pointer_string(buf, end, ptr, spec);
804 
805 	/* When debugging early boot use non-cryptographically secure hash. */
806 	if (unlikely(debug_boot_weak_hash)) {
807 		hashval = hash_long((unsigned long)ptr, 32);
808 		return pointer_string(buf, end, (const void *)hashval, spec);
809 	}
810 
811 	ret = __ptr_to_hashval(ptr, &hashval);
812 	if (ret) {
813 		spec.field_width = 2 * sizeof(ptr);
814 		/* string length must be less than default_width */
815 		return error_string(buf, end, str, spec);
816 	}
817 
818 	return pointer_string(buf, end, (const void *)hashval, spec);
819 }
820 
821 int kptr_restrict __read_mostly;
822 
823 static noinline_for_stack
824 char *restricted_pointer(char *buf, char *end, const void *ptr,
825 			 struct printf_spec spec)
826 {
827 	switch (kptr_restrict) {
828 	case 0:
829 		/* Handle as %p, hash and do _not_ leak addresses. */
830 		return ptr_to_id(buf, end, ptr, spec);
831 	case 1: {
832 		const struct cred *cred;
833 
834 		/*
835 		 * kptr_restrict==1 cannot be used in IRQ context
836 		 * because its test for CAP_SYSLOG would be meaningless.
837 		 */
838 		if (in_irq() || in_serving_softirq() || in_nmi()) {
839 			if (spec.field_width == -1)
840 				spec.field_width = 2 * sizeof(ptr);
841 			return error_string(buf, end, "pK-error", spec);
842 		}
843 
844 		/*
845 		 * Only print the real pointer value if the current
846 		 * process has CAP_SYSLOG and is running with the
847 		 * same credentials it started with. This is because
848 		 * access to files is checked at open() time, but %pK
849 		 * checks permission at read() time. We don't want to
850 		 * leak pointer values if a binary opens a file using
851 		 * %pK and then elevates privileges before reading it.
852 		 */
853 		cred = current_cred();
854 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
855 		    !uid_eq(cred->euid, cred->uid) ||
856 		    !gid_eq(cred->egid, cred->gid))
857 			ptr = NULL;
858 		break;
859 	}
860 	case 2:
861 	default:
862 		/* Always print 0's for %pK */
863 		ptr = NULL;
864 		break;
865 	}
866 
867 	return pointer_string(buf, end, ptr, spec);
868 }
869 
870 static noinline_for_stack
871 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
872 		  const char *fmt)
873 {
874 	const char *array[4], *s;
875 	const struct dentry *p;
876 	int depth;
877 	int i, n;
878 
879 	switch (fmt[1]) {
880 		case '2': case '3': case '4':
881 			depth = fmt[1] - '0';
882 			break;
883 		default:
884 			depth = 1;
885 	}
886 
887 	rcu_read_lock();
888 	for (i = 0; i < depth; i++, d = p) {
889 		if (check_pointer(&buf, end, d, spec)) {
890 			rcu_read_unlock();
891 			return buf;
892 		}
893 
894 		p = READ_ONCE(d->d_parent);
895 		array[i] = READ_ONCE(d->d_name.name);
896 		if (p == d) {
897 			if (i)
898 				array[i] = "";
899 			i++;
900 			break;
901 		}
902 	}
903 	s = array[--i];
904 	for (n = 0; n != spec.precision; n++, buf++) {
905 		char c = *s++;
906 		if (!c) {
907 			if (!i)
908 				break;
909 			c = '/';
910 			s = array[--i];
911 		}
912 		if (buf < end)
913 			*buf = c;
914 	}
915 	rcu_read_unlock();
916 	return widen_string(buf, n, end, spec);
917 }
918 
919 static noinline_for_stack
920 char *file_dentry_name(char *buf, char *end, const struct file *f,
921 			struct printf_spec spec, const char *fmt)
922 {
923 	if (check_pointer(&buf, end, f, spec))
924 		return buf;
925 
926 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
927 }
928 #ifdef CONFIG_BLOCK
929 static noinline_for_stack
930 char *bdev_name(char *buf, char *end, struct block_device *bdev,
931 		struct printf_spec spec, const char *fmt)
932 {
933 	struct gendisk *hd;
934 
935 	if (check_pointer(&buf, end, bdev, spec))
936 		return buf;
937 
938 	hd = bdev->bd_disk;
939 	buf = string(buf, end, hd->disk_name, spec);
940 	if (bdev->bd_part->partno) {
941 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
942 			if (buf < end)
943 				*buf = 'p';
944 			buf++;
945 		}
946 		buf = number(buf, end, bdev->bd_part->partno, spec);
947 	}
948 	return buf;
949 }
950 #endif
951 
952 static noinline_for_stack
953 char *symbol_string(char *buf, char *end, void *ptr,
954 		    struct printf_spec spec, const char *fmt)
955 {
956 	unsigned long value;
957 #ifdef CONFIG_KALLSYMS
958 	char sym[KSYM_SYMBOL_LEN];
959 #endif
960 
961 	if (fmt[1] == 'R')
962 		ptr = __builtin_extract_return_addr(ptr);
963 	value = (unsigned long)ptr;
964 
965 #ifdef CONFIG_KALLSYMS
966 	if (*fmt == 'B')
967 		sprint_backtrace(sym, value);
968 	else if (*fmt != 's')
969 		sprint_symbol(sym, value);
970 	else
971 		sprint_symbol_no_offset(sym, value);
972 
973 	return string_nocheck(buf, end, sym, spec);
974 #else
975 	return special_hex_number(buf, end, value, sizeof(void *));
976 #endif
977 }
978 
979 static const struct printf_spec default_str_spec = {
980 	.field_width = -1,
981 	.precision = -1,
982 };
983 
984 static const struct printf_spec default_flag_spec = {
985 	.base = 16,
986 	.precision = -1,
987 	.flags = SPECIAL | SMALL,
988 };
989 
990 static const struct printf_spec default_dec_spec = {
991 	.base = 10,
992 	.precision = -1,
993 };
994 
995 static const struct printf_spec default_dec02_spec = {
996 	.base = 10,
997 	.field_width = 2,
998 	.precision = -1,
999 	.flags = ZEROPAD,
1000 };
1001 
1002 static const struct printf_spec default_dec04_spec = {
1003 	.base = 10,
1004 	.field_width = 4,
1005 	.precision = -1,
1006 	.flags = ZEROPAD,
1007 };
1008 
1009 static noinline_for_stack
1010 char *resource_string(char *buf, char *end, struct resource *res,
1011 		      struct printf_spec spec, const char *fmt)
1012 {
1013 #ifndef IO_RSRC_PRINTK_SIZE
1014 #define IO_RSRC_PRINTK_SIZE	6
1015 #endif
1016 
1017 #ifndef MEM_RSRC_PRINTK_SIZE
1018 #define MEM_RSRC_PRINTK_SIZE	10
1019 #endif
1020 	static const struct printf_spec io_spec = {
1021 		.base = 16,
1022 		.field_width = IO_RSRC_PRINTK_SIZE,
1023 		.precision = -1,
1024 		.flags = SPECIAL | SMALL | ZEROPAD,
1025 	};
1026 	static const struct printf_spec mem_spec = {
1027 		.base = 16,
1028 		.field_width = MEM_RSRC_PRINTK_SIZE,
1029 		.precision = -1,
1030 		.flags = SPECIAL | SMALL | ZEROPAD,
1031 	};
1032 	static const struct printf_spec bus_spec = {
1033 		.base = 16,
1034 		.field_width = 2,
1035 		.precision = -1,
1036 		.flags = SMALL | ZEROPAD,
1037 	};
1038 	static const struct printf_spec str_spec = {
1039 		.field_width = -1,
1040 		.precision = 10,
1041 		.flags = LEFT,
1042 	};
1043 
1044 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1045 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1046 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1047 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1048 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1049 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1050 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1051 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1052 
1053 	char *p = sym, *pend = sym + sizeof(sym);
1054 	int decode = (fmt[0] == 'R') ? 1 : 0;
1055 	const struct printf_spec *specp;
1056 
1057 	if (check_pointer(&buf, end, res, spec))
1058 		return buf;
1059 
1060 	*p++ = '[';
1061 	if (res->flags & IORESOURCE_IO) {
1062 		p = string_nocheck(p, pend, "io  ", str_spec);
1063 		specp = &io_spec;
1064 	} else if (res->flags & IORESOURCE_MEM) {
1065 		p = string_nocheck(p, pend, "mem ", str_spec);
1066 		specp = &mem_spec;
1067 	} else if (res->flags & IORESOURCE_IRQ) {
1068 		p = string_nocheck(p, pend, "irq ", str_spec);
1069 		specp = &default_dec_spec;
1070 	} else if (res->flags & IORESOURCE_DMA) {
1071 		p = string_nocheck(p, pend, "dma ", str_spec);
1072 		specp = &default_dec_spec;
1073 	} else if (res->flags & IORESOURCE_BUS) {
1074 		p = string_nocheck(p, pend, "bus ", str_spec);
1075 		specp = &bus_spec;
1076 	} else {
1077 		p = string_nocheck(p, pend, "??? ", str_spec);
1078 		specp = &mem_spec;
1079 		decode = 0;
1080 	}
1081 	if (decode && res->flags & IORESOURCE_UNSET) {
1082 		p = string_nocheck(p, pend, "size ", str_spec);
1083 		p = number(p, pend, resource_size(res), *specp);
1084 	} else {
1085 		p = number(p, pend, res->start, *specp);
1086 		if (res->start != res->end) {
1087 			*p++ = '-';
1088 			p = number(p, pend, res->end, *specp);
1089 		}
1090 	}
1091 	if (decode) {
1092 		if (res->flags & IORESOURCE_MEM_64)
1093 			p = string_nocheck(p, pend, " 64bit", str_spec);
1094 		if (res->flags & IORESOURCE_PREFETCH)
1095 			p = string_nocheck(p, pend, " pref", str_spec);
1096 		if (res->flags & IORESOURCE_WINDOW)
1097 			p = string_nocheck(p, pend, " window", str_spec);
1098 		if (res->flags & IORESOURCE_DISABLED)
1099 			p = string_nocheck(p, pend, " disabled", str_spec);
1100 	} else {
1101 		p = string_nocheck(p, pend, " flags ", str_spec);
1102 		p = number(p, pend, res->flags, default_flag_spec);
1103 	}
1104 	*p++ = ']';
1105 	*p = '\0';
1106 
1107 	return string_nocheck(buf, end, sym, spec);
1108 }
1109 
1110 static noinline_for_stack
1111 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1112 		 const char *fmt)
1113 {
1114 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1115 				   negative value, fallback to the default */
1116 	char separator;
1117 
1118 	if (spec.field_width == 0)
1119 		/* nothing to print */
1120 		return buf;
1121 
1122 	if (check_pointer(&buf, end, addr, spec))
1123 		return buf;
1124 
1125 	switch (fmt[1]) {
1126 	case 'C':
1127 		separator = ':';
1128 		break;
1129 	case 'D':
1130 		separator = '-';
1131 		break;
1132 	case 'N':
1133 		separator = 0;
1134 		break;
1135 	default:
1136 		separator = ' ';
1137 		break;
1138 	}
1139 
1140 	if (spec.field_width > 0)
1141 		len = min_t(int, spec.field_width, 64);
1142 
1143 	for (i = 0; i < len; ++i) {
1144 		if (buf < end)
1145 			*buf = hex_asc_hi(addr[i]);
1146 		++buf;
1147 		if (buf < end)
1148 			*buf = hex_asc_lo(addr[i]);
1149 		++buf;
1150 
1151 		if (separator && i != len - 1) {
1152 			if (buf < end)
1153 				*buf = separator;
1154 			++buf;
1155 		}
1156 	}
1157 
1158 	return buf;
1159 }
1160 
1161 static noinline_for_stack
1162 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1163 		    struct printf_spec spec, const char *fmt)
1164 {
1165 	const int CHUNKSZ = 32;
1166 	int nr_bits = max_t(int, spec.field_width, 0);
1167 	int i, chunksz;
1168 	bool first = true;
1169 
1170 	if (check_pointer(&buf, end, bitmap, spec))
1171 		return buf;
1172 
1173 	/* reused to print numbers */
1174 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1175 
1176 	chunksz = nr_bits & (CHUNKSZ - 1);
1177 	if (chunksz == 0)
1178 		chunksz = CHUNKSZ;
1179 
1180 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1181 	for (; i >= 0; i -= CHUNKSZ) {
1182 		u32 chunkmask, val;
1183 		int word, bit;
1184 
1185 		chunkmask = ((1ULL << chunksz) - 1);
1186 		word = i / BITS_PER_LONG;
1187 		bit = i % BITS_PER_LONG;
1188 		val = (bitmap[word] >> bit) & chunkmask;
1189 
1190 		if (!first) {
1191 			if (buf < end)
1192 				*buf = ',';
1193 			buf++;
1194 		}
1195 		first = false;
1196 
1197 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1198 		buf = number(buf, end, val, spec);
1199 
1200 		chunksz = CHUNKSZ;
1201 	}
1202 	return buf;
1203 }
1204 
1205 static noinline_for_stack
1206 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1207 			 struct printf_spec spec, const char *fmt)
1208 {
1209 	int nr_bits = max_t(int, spec.field_width, 0);
1210 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
1211 	int cur, rbot, rtop;
1212 	bool first = true;
1213 
1214 	if (check_pointer(&buf, end, bitmap, spec))
1215 		return buf;
1216 
1217 	rbot = cur = find_first_bit(bitmap, nr_bits);
1218 	while (cur < nr_bits) {
1219 		rtop = cur;
1220 		cur = find_next_bit(bitmap, nr_bits, cur + 1);
1221 		if (cur < nr_bits && cur <= rtop + 1)
1222 			continue;
1223 
1224 		if (!first) {
1225 			if (buf < end)
1226 				*buf = ',';
1227 			buf++;
1228 		}
1229 		first = false;
1230 
1231 		buf = number(buf, end, rbot, default_dec_spec);
1232 		if (rbot < rtop) {
1233 			if (buf < end)
1234 				*buf = '-';
1235 			buf++;
1236 
1237 			buf = number(buf, end, rtop, default_dec_spec);
1238 		}
1239 
1240 		rbot = cur;
1241 	}
1242 	return buf;
1243 }
1244 
1245 static noinline_for_stack
1246 char *mac_address_string(char *buf, char *end, u8 *addr,
1247 			 struct printf_spec spec, const char *fmt)
1248 {
1249 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1250 	char *p = mac_addr;
1251 	int i;
1252 	char separator;
1253 	bool reversed = false;
1254 
1255 	if (check_pointer(&buf, end, addr, spec))
1256 		return buf;
1257 
1258 	switch (fmt[1]) {
1259 	case 'F':
1260 		separator = '-';
1261 		break;
1262 
1263 	case 'R':
1264 		reversed = true;
1265 		/* fall through */
1266 
1267 	default:
1268 		separator = ':';
1269 		break;
1270 	}
1271 
1272 	for (i = 0; i < 6; i++) {
1273 		if (reversed)
1274 			p = hex_byte_pack(p, addr[5 - i]);
1275 		else
1276 			p = hex_byte_pack(p, addr[i]);
1277 
1278 		if (fmt[0] == 'M' && i != 5)
1279 			*p++ = separator;
1280 	}
1281 	*p = '\0';
1282 
1283 	return string_nocheck(buf, end, mac_addr, spec);
1284 }
1285 
1286 static noinline_for_stack
1287 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1288 {
1289 	int i;
1290 	bool leading_zeros = (fmt[0] == 'i');
1291 	int index;
1292 	int step;
1293 
1294 	switch (fmt[2]) {
1295 	case 'h':
1296 #ifdef __BIG_ENDIAN
1297 		index = 0;
1298 		step = 1;
1299 #else
1300 		index = 3;
1301 		step = -1;
1302 #endif
1303 		break;
1304 	case 'l':
1305 		index = 3;
1306 		step = -1;
1307 		break;
1308 	case 'n':
1309 	case 'b':
1310 	default:
1311 		index = 0;
1312 		step = 1;
1313 		break;
1314 	}
1315 	for (i = 0; i < 4; i++) {
1316 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1317 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1318 		if (leading_zeros) {
1319 			if (digits < 3)
1320 				*p++ = '0';
1321 			if (digits < 2)
1322 				*p++ = '0';
1323 		}
1324 		/* reverse the digits in the quad */
1325 		while (digits--)
1326 			*p++ = temp[digits];
1327 		if (i < 3)
1328 			*p++ = '.';
1329 		index += step;
1330 	}
1331 	*p = '\0';
1332 
1333 	return p;
1334 }
1335 
1336 static noinline_for_stack
1337 char *ip6_compressed_string(char *p, const char *addr)
1338 {
1339 	int i, j, range;
1340 	unsigned char zerolength[8];
1341 	int longest = 1;
1342 	int colonpos = -1;
1343 	u16 word;
1344 	u8 hi, lo;
1345 	bool needcolon = false;
1346 	bool useIPv4;
1347 	struct in6_addr in6;
1348 
1349 	memcpy(&in6, addr, sizeof(struct in6_addr));
1350 
1351 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1352 
1353 	memset(zerolength, 0, sizeof(zerolength));
1354 
1355 	if (useIPv4)
1356 		range = 6;
1357 	else
1358 		range = 8;
1359 
1360 	/* find position of longest 0 run */
1361 	for (i = 0; i < range; i++) {
1362 		for (j = i; j < range; j++) {
1363 			if (in6.s6_addr16[j] != 0)
1364 				break;
1365 			zerolength[i]++;
1366 		}
1367 	}
1368 	for (i = 0; i < range; i++) {
1369 		if (zerolength[i] > longest) {
1370 			longest = zerolength[i];
1371 			colonpos = i;
1372 		}
1373 	}
1374 	if (longest == 1)		/* don't compress a single 0 */
1375 		colonpos = -1;
1376 
1377 	/* emit address */
1378 	for (i = 0; i < range; i++) {
1379 		if (i == colonpos) {
1380 			if (needcolon || i == 0)
1381 				*p++ = ':';
1382 			*p++ = ':';
1383 			needcolon = false;
1384 			i += longest - 1;
1385 			continue;
1386 		}
1387 		if (needcolon) {
1388 			*p++ = ':';
1389 			needcolon = false;
1390 		}
1391 		/* hex u16 without leading 0s */
1392 		word = ntohs(in6.s6_addr16[i]);
1393 		hi = word >> 8;
1394 		lo = word & 0xff;
1395 		if (hi) {
1396 			if (hi > 0x0f)
1397 				p = hex_byte_pack(p, hi);
1398 			else
1399 				*p++ = hex_asc_lo(hi);
1400 			p = hex_byte_pack(p, lo);
1401 		}
1402 		else if (lo > 0x0f)
1403 			p = hex_byte_pack(p, lo);
1404 		else
1405 			*p++ = hex_asc_lo(lo);
1406 		needcolon = true;
1407 	}
1408 
1409 	if (useIPv4) {
1410 		if (needcolon)
1411 			*p++ = ':';
1412 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1413 	}
1414 	*p = '\0';
1415 
1416 	return p;
1417 }
1418 
1419 static noinline_for_stack
1420 char *ip6_string(char *p, const char *addr, const char *fmt)
1421 {
1422 	int i;
1423 
1424 	for (i = 0; i < 8; i++) {
1425 		p = hex_byte_pack(p, *addr++);
1426 		p = hex_byte_pack(p, *addr++);
1427 		if (fmt[0] == 'I' && i != 7)
1428 			*p++ = ':';
1429 	}
1430 	*p = '\0';
1431 
1432 	return p;
1433 }
1434 
1435 static noinline_for_stack
1436 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1437 		      struct printf_spec spec, const char *fmt)
1438 {
1439 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1440 
1441 	if (fmt[0] == 'I' && fmt[2] == 'c')
1442 		ip6_compressed_string(ip6_addr, addr);
1443 	else
1444 		ip6_string(ip6_addr, addr, fmt);
1445 
1446 	return string_nocheck(buf, end, ip6_addr, spec);
1447 }
1448 
1449 static noinline_for_stack
1450 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1451 		      struct printf_spec spec, const char *fmt)
1452 {
1453 	char ip4_addr[sizeof("255.255.255.255")];
1454 
1455 	ip4_string(ip4_addr, addr, fmt);
1456 
1457 	return string_nocheck(buf, end, ip4_addr, spec);
1458 }
1459 
1460 static noinline_for_stack
1461 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1462 			 struct printf_spec spec, const char *fmt)
1463 {
1464 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1465 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1466 		      sizeof(":12345") + sizeof("/123456789") +
1467 		      sizeof("%1234567890")];
1468 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1469 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1470 	char fmt6[2] = { fmt[0], '6' };
1471 	u8 off = 0;
1472 
1473 	fmt++;
1474 	while (isalpha(*++fmt)) {
1475 		switch (*fmt) {
1476 		case 'p':
1477 			have_p = true;
1478 			break;
1479 		case 'f':
1480 			have_f = true;
1481 			break;
1482 		case 's':
1483 			have_s = true;
1484 			break;
1485 		case 'c':
1486 			have_c = true;
1487 			break;
1488 		}
1489 	}
1490 
1491 	if (have_p || have_s || have_f) {
1492 		*p = '[';
1493 		off = 1;
1494 	}
1495 
1496 	if (fmt6[0] == 'I' && have_c)
1497 		p = ip6_compressed_string(ip6_addr + off, addr);
1498 	else
1499 		p = ip6_string(ip6_addr + off, addr, fmt6);
1500 
1501 	if (have_p || have_s || have_f)
1502 		*p++ = ']';
1503 
1504 	if (have_p) {
1505 		*p++ = ':';
1506 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1507 	}
1508 	if (have_f) {
1509 		*p++ = '/';
1510 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1511 					  IPV6_FLOWINFO_MASK), spec);
1512 	}
1513 	if (have_s) {
1514 		*p++ = '%';
1515 		p = number(p, pend, sa->sin6_scope_id, spec);
1516 	}
1517 	*p = '\0';
1518 
1519 	return string_nocheck(buf, end, ip6_addr, spec);
1520 }
1521 
1522 static noinline_for_stack
1523 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1524 			 struct printf_spec spec, const char *fmt)
1525 {
1526 	bool have_p = false;
1527 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1528 	char *pend = ip4_addr + sizeof(ip4_addr);
1529 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1530 	char fmt4[3] = { fmt[0], '4', 0 };
1531 
1532 	fmt++;
1533 	while (isalpha(*++fmt)) {
1534 		switch (*fmt) {
1535 		case 'p':
1536 			have_p = true;
1537 			break;
1538 		case 'h':
1539 		case 'l':
1540 		case 'n':
1541 		case 'b':
1542 			fmt4[2] = *fmt;
1543 			break;
1544 		}
1545 	}
1546 
1547 	p = ip4_string(ip4_addr, addr, fmt4);
1548 	if (have_p) {
1549 		*p++ = ':';
1550 		p = number(p, pend, ntohs(sa->sin_port), spec);
1551 	}
1552 	*p = '\0';
1553 
1554 	return string_nocheck(buf, end, ip4_addr, spec);
1555 }
1556 
1557 static noinline_for_stack
1558 char *ip_addr_string(char *buf, char *end, const void *ptr,
1559 		     struct printf_spec spec, const char *fmt)
1560 {
1561 	char *err_fmt_msg;
1562 
1563 	if (check_pointer(&buf, end, ptr, spec))
1564 		return buf;
1565 
1566 	switch (fmt[1]) {
1567 	case '6':
1568 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1569 	case '4':
1570 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1571 	case 'S': {
1572 		const union {
1573 			struct sockaddr		raw;
1574 			struct sockaddr_in	v4;
1575 			struct sockaddr_in6	v6;
1576 		} *sa = ptr;
1577 
1578 		switch (sa->raw.sa_family) {
1579 		case AF_INET:
1580 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1581 		case AF_INET6:
1582 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1583 		default:
1584 			return error_string(buf, end, "(einval)", spec);
1585 		}}
1586 	}
1587 
1588 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1589 	return error_string(buf, end, err_fmt_msg, spec);
1590 }
1591 
1592 static noinline_for_stack
1593 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1594 		     const char *fmt)
1595 {
1596 	bool found = true;
1597 	int count = 1;
1598 	unsigned int flags = 0;
1599 	int len;
1600 
1601 	if (spec.field_width == 0)
1602 		return buf;				/* nothing to print */
1603 
1604 	if (check_pointer(&buf, end, addr, spec))
1605 		return buf;
1606 
1607 	do {
1608 		switch (fmt[count++]) {
1609 		case 'a':
1610 			flags |= ESCAPE_ANY;
1611 			break;
1612 		case 'c':
1613 			flags |= ESCAPE_SPECIAL;
1614 			break;
1615 		case 'h':
1616 			flags |= ESCAPE_HEX;
1617 			break;
1618 		case 'n':
1619 			flags |= ESCAPE_NULL;
1620 			break;
1621 		case 'o':
1622 			flags |= ESCAPE_OCTAL;
1623 			break;
1624 		case 'p':
1625 			flags |= ESCAPE_NP;
1626 			break;
1627 		case 's':
1628 			flags |= ESCAPE_SPACE;
1629 			break;
1630 		default:
1631 			found = false;
1632 			break;
1633 		}
1634 	} while (found);
1635 
1636 	if (!flags)
1637 		flags = ESCAPE_ANY_NP;
1638 
1639 	len = spec.field_width < 0 ? 1 : spec.field_width;
1640 
1641 	/*
1642 	 * string_escape_mem() writes as many characters as it can to
1643 	 * the given buffer, and returns the total size of the output
1644 	 * had the buffer been big enough.
1645 	 */
1646 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1647 
1648 	return buf;
1649 }
1650 
1651 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1652 		       struct printf_spec spec, const char *fmt)
1653 {
1654 	va_list va;
1655 
1656 	if (check_pointer(&buf, end, va_fmt, spec))
1657 		return buf;
1658 
1659 	va_copy(va, *va_fmt->va);
1660 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1661 	va_end(va);
1662 
1663 	return buf;
1664 }
1665 
1666 static noinline_for_stack
1667 char *uuid_string(char *buf, char *end, const u8 *addr,
1668 		  struct printf_spec spec, const char *fmt)
1669 {
1670 	char uuid[UUID_STRING_LEN + 1];
1671 	char *p = uuid;
1672 	int i;
1673 	const u8 *index = uuid_index;
1674 	bool uc = false;
1675 
1676 	if (check_pointer(&buf, end, addr, spec))
1677 		return buf;
1678 
1679 	switch (*(++fmt)) {
1680 	case 'L':
1681 		uc = true;		/* fall-through */
1682 	case 'l':
1683 		index = guid_index;
1684 		break;
1685 	case 'B':
1686 		uc = true;
1687 		break;
1688 	}
1689 
1690 	for (i = 0; i < 16; i++) {
1691 		if (uc)
1692 			p = hex_byte_pack_upper(p, addr[index[i]]);
1693 		else
1694 			p = hex_byte_pack(p, addr[index[i]]);
1695 		switch (i) {
1696 		case 3:
1697 		case 5:
1698 		case 7:
1699 		case 9:
1700 			*p++ = '-';
1701 			break;
1702 		}
1703 	}
1704 
1705 	*p = 0;
1706 
1707 	return string_nocheck(buf, end, uuid, spec);
1708 }
1709 
1710 static noinline_for_stack
1711 char *netdev_bits(char *buf, char *end, const void *addr,
1712 		  struct printf_spec spec,  const char *fmt)
1713 {
1714 	unsigned long long num;
1715 	int size;
1716 
1717 	if (check_pointer(&buf, end, addr, spec))
1718 		return buf;
1719 
1720 	switch (fmt[1]) {
1721 	case 'F':
1722 		num = *(const netdev_features_t *)addr;
1723 		size = sizeof(netdev_features_t);
1724 		break;
1725 	default:
1726 		return error_string(buf, end, "(%pN?)", spec);
1727 	}
1728 
1729 	return special_hex_number(buf, end, num, size);
1730 }
1731 
1732 static noinline_for_stack
1733 char *address_val(char *buf, char *end, const void *addr,
1734 		  struct printf_spec spec, const char *fmt)
1735 {
1736 	unsigned long long num;
1737 	int size;
1738 
1739 	if (check_pointer(&buf, end, addr, spec))
1740 		return buf;
1741 
1742 	switch (fmt[1]) {
1743 	case 'd':
1744 		num = *(const dma_addr_t *)addr;
1745 		size = sizeof(dma_addr_t);
1746 		break;
1747 	case 'p':
1748 	default:
1749 		num = *(const phys_addr_t *)addr;
1750 		size = sizeof(phys_addr_t);
1751 		break;
1752 	}
1753 
1754 	return special_hex_number(buf, end, num, size);
1755 }
1756 
1757 static noinline_for_stack
1758 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1759 {
1760 	int year = tm->tm_year + (r ? 0 : 1900);
1761 	int mon = tm->tm_mon + (r ? 0 : 1);
1762 
1763 	buf = number(buf, end, year, default_dec04_spec);
1764 	if (buf < end)
1765 		*buf = '-';
1766 	buf++;
1767 
1768 	buf = number(buf, end, mon, default_dec02_spec);
1769 	if (buf < end)
1770 		*buf = '-';
1771 	buf++;
1772 
1773 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1774 }
1775 
1776 static noinline_for_stack
1777 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1778 {
1779 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1780 	if (buf < end)
1781 		*buf = ':';
1782 	buf++;
1783 
1784 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1785 	if (buf < end)
1786 		*buf = ':';
1787 	buf++;
1788 
1789 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1790 }
1791 
1792 static noinline_for_stack
1793 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1794 	      struct printf_spec spec, const char *fmt)
1795 {
1796 	bool have_t = true, have_d = true;
1797 	bool raw = false;
1798 	int count = 2;
1799 
1800 	if (check_pointer(&buf, end, tm, spec))
1801 		return buf;
1802 
1803 	switch (fmt[count]) {
1804 	case 'd':
1805 		have_t = false;
1806 		count++;
1807 		break;
1808 	case 't':
1809 		have_d = false;
1810 		count++;
1811 		break;
1812 	}
1813 
1814 	raw = fmt[count] == 'r';
1815 
1816 	if (have_d)
1817 		buf = date_str(buf, end, tm, raw);
1818 	if (have_d && have_t) {
1819 		/* Respect ISO 8601 */
1820 		if (buf < end)
1821 			*buf = 'T';
1822 		buf++;
1823 	}
1824 	if (have_t)
1825 		buf = time_str(buf, end, tm, raw);
1826 
1827 	return buf;
1828 }
1829 
1830 static noinline_for_stack
1831 char *time64_str(char *buf, char *end, const time64_t time,
1832 		 struct printf_spec spec, const char *fmt)
1833 {
1834 	struct rtc_time rtc_time;
1835 	struct tm tm;
1836 
1837 	time64_to_tm(time, 0, &tm);
1838 
1839 	rtc_time.tm_sec = tm.tm_sec;
1840 	rtc_time.tm_min = tm.tm_min;
1841 	rtc_time.tm_hour = tm.tm_hour;
1842 	rtc_time.tm_mday = tm.tm_mday;
1843 	rtc_time.tm_mon = tm.tm_mon;
1844 	rtc_time.tm_year = tm.tm_year;
1845 	rtc_time.tm_wday = tm.tm_wday;
1846 	rtc_time.tm_yday = tm.tm_yday;
1847 
1848 	rtc_time.tm_isdst = 0;
1849 
1850 	return rtc_str(buf, end, &rtc_time, spec, fmt);
1851 }
1852 
1853 static noinline_for_stack
1854 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1855 		    const char *fmt)
1856 {
1857 	switch (fmt[1]) {
1858 	case 'R':
1859 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1860 	case 'T':
1861 		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1862 	default:
1863 		return error_string(buf, end, "(%pt?)", spec);
1864 	}
1865 }
1866 
1867 static noinline_for_stack
1868 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1869 	    const char *fmt)
1870 {
1871 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1872 		return error_string(buf, end, "(%pC?)", spec);
1873 
1874 	if (check_pointer(&buf, end, clk, spec))
1875 		return buf;
1876 
1877 	switch (fmt[1]) {
1878 	case 'n':
1879 	default:
1880 #ifdef CONFIG_COMMON_CLK
1881 		return string(buf, end, __clk_get_name(clk), spec);
1882 #else
1883 		return ptr_to_id(buf, end, clk, spec);
1884 #endif
1885 	}
1886 }
1887 
1888 static
1889 char *format_flags(char *buf, char *end, unsigned long flags,
1890 					const struct trace_print_flags *names)
1891 {
1892 	unsigned long mask;
1893 
1894 	for ( ; flags && names->name; names++) {
1895 		mask = names->mask;
1896 		if ((flags & mask) != mask)
1897 			continue;
1898 
1899 		buf = string(buf, end, names->name, default_str_spec);
1900 
1901 		flags &= ~mask;
1902 		if (flags) {
1903 			if (buf < end)
1904 				*buf = '|';
1905 			buf++;
1906 		}
1907 	}
1908 
1909 	if (flags)
1910 		buf = number(buf, end, flags, default_flag_spec);
1911 
1912 	return buf;
1913 }
1914 
1915 static noinline_for_stack
1916 char *flags_string(char *buf, char *end, void *flags_ptr,
1917 		   struct printf_spec spec, const char *fmt)
1918 {
1919 	unsigned long flags;
1920 	const struct trace_print_flags *names;
1921 
1922 	if (check_pointer(&buf, end, flags_ptr, spec))
1923 		return buf;
1924 
1925 	switch (fmt[1]) {
1926 	case 'p':
1927 		flags = *(unsigned long *)flags_ptr;
1928 		/* Remove zone id */
1929 		flags &= (1UL << NR_PAGEFLAGS) - 1;
1930 		names = pageflag_names;
1931 		break;
1932 	case 'v':
1933 		flags = *(unsigned long *)flags_ptr;
1934 		names = vmaflag_names;
1935 		break;
1936 	case 'g':
1937 		flags = *(gfp_t *)flags_ptr;
1938 		names = gfpflag_names;
1939 		break;
1940 	default:
1941 		return error_string(buf, end, "(%pG?)", spec);
1942 	}
1943 
1944 	return format_flags(buf, end, flags, names);
1945 }
1946 
1947 static noinline_for_stack
1948 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
1949 			      char *end)
1950 {
1951 	int depth;
1952 
1953 	/* Loop starting from the root node to the current node. */
1954 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
1955 		struct fwnode_handle *__fwnode =
1956 			fwnode_get_nth_parent(fwnode, depth);
1957 
1958 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
1959 			     default_str_spec);
1960 		buf = string(buf, end, fwnode_get_name(__fwnode),
1961 			     default_str_spec);
1962 
1963 		fwnode_handle_put(__fwnode);
1964 	}
1965 
1966 	return buf;
1967 }
1968 
1969 static noinline_for_stack
1970 char *device_node_string(char *buf, char *end, struct device_node *dn,
1971 			 struct printf_spec spec, const char *fmt)
1972 {
1973 	char tbuf[sizeof("xxxx") + 1];
1974 	const char *p;
1975 	int ret;
1976 	char *buf_start = buf;
1977 	struct property *prop;
1978 	bool has_mult, pass;
1979 	static const struct printf_spec num_spec = {
1980 		.flags = SMALL,
1981 		.field_width = -1,
1982 		.precision = -1,
1983 		.base = 10,
1984 	};
1985 
1986 	struct printf_spec str_spec = spec;
1987 	str_spec.field_width = -1;
1988 
1989 	if (fmt[0] != 'F')
1990 		return error_string(buf, end, "(%pO?)", spec);
1991 
1992 	if (!IS_ENABLED(CONFIG_OF))
1993 		return error_string(buf, end, "(%pOF?)", spec);
1994 
1995 	if (check_pointer(&buf, end, dn, spec))
1996 		return buf;
1997 
1998 	/* simple case without anything any more format specifiers */
1999 	fmt++;
2000 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2001 		fmt = "f";
2002 
2003 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2004 		int precision;
2005 		if (pass) {
2006 			if (buf < end)
2007 				*buf = ':';
2008 			buf++;
2009 		}
2010 
2011 		switch (*fmt) {
2012 		case 'f':	/* full_name */
2013 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2014 						      end);
2015 			break;
2016 		case 'n':	/* name */
2017 			p = fwnode_get_name(of_fwnode_handle(dn));
2018 			precision = str_spec.precision;
2019 			str_spec.precision = strchrnul(p, '@') - p;
2020 			buf = string(buf, end, p, str_spec);
2021 			str_spec.precision = precision;
2022 			break;
2023 		case 'p':	/* phandle */
2024 			buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
2025 			break;
2026 		case 'P':	/* path-spec */
2027 			p = fwnode_get_name(of_fwnode_handle(dn));
2028 			if (!p[1])
2029 				p = "/";
2030 			buf = string(buf, end, p, str_spec);
2031 			break;
2032 		case 'F':	/* flags */
2033 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2034 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2035 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2036 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2037 			tbuf[4] = 0;
2038 			buf = string_nocheck(buf, end, tbuf, str_spec);
2039 			break;
2040 		case 'c':	/* major compatible string */
2041 			ret = of_property_read_string(dn, "compatible", &p);
2042 			if (!ret)
2043 				buf = string(buf, end, p, str_spec);
2044 			break;
2045 		case 'C':	/* full compatible string */
2046 			has_mult = false;
2047 			of_property_for_each_string(dn, "compatible", prop, p) {
2048 				if (has_mult)
2049 					buf = string_nocheck(buf, end, ",", str_spec);
2050 				buf = string_nocheck(buf, end, "\"", str_spec);
2051 				buf = string(buf, end, p, str_spec);
2052 				buf = string_nocheck(buf, end, "\"", str_spec);
2053 
2054 				has_mult = true;
2055 			}
2056 			break;
2057 		default:
2058 			break;
2059 		}
2060 	}
2061 
2062 	return widen_string(buf, buf - buf_start, end, spec);
2063 }
2064 
2065 static noinline_for_stack
2066 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2067 		    struct printf_spec spec, const char *fmt)
2068 {
2069 	struct printf_spec str_spec = spec;
2070 	char *buf_start = buf;
2071 
2072 	str_spec.field_width = -1;
2073 
2074 	if (*fmt != 'w')
2075 		return error_string(buf, end, "(%pf?)", spec);
2076 
2077 	if (check_pointer(&buf, end, fwnode, spec))
2078 		return buf;
2079 
2080 	fmt++;
2081 
2082 	switch (*fmt) {
2083 	case 'P':	/* name */
2084 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2085 		break;
2086 	case 'f':	/* full_name */
2087 	default:
2088 		buf = fwnode_full_name_string(fwnode, buf, end);
2089 		break;
2090 	}
2091 
2092 	return widen_string(buf, buf - buf_start, end, spec);
2093 }
2094 
2095 /*
2096  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2097  * by an extra set of alphanumeric characters that are extended format
2098  * specifiers.
2099  *
2100  * Please update scripts/checkpatch.pl when adding/removing conversion
2101  * characters.  (Search for "check for vsprintf extension").
2102  *
2103  * Right now we handle:
2104  *
2105  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2106  * - 's' For symbolic direct pointers (or function descriptors) without offset
2107  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2108  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2109  *	    %ps and %pS. Be careful when re-using these specifiers.
2110  * - 'B' For backtraced symbolic direct pointers with offset
2111  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2112  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2113  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2114  *       width which must be explicitly specified either as part of the
2115  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2116  *       range-list format instead of hex format
2117  * - 'M' For a 6-byte MAC address, it prints the address in the
2118  *       usual colon-separated hex notation
2119  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2120  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2121  *       with a dash-separated hex notation
2122  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2123  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2124  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2125  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2126  *       [S][pfs]
2127  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2128  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2129  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2130  *       IPv6 omits the colons (01020304...0f)
2131  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2132  *       [S][pfs]
2133  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2134  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2135  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2136  * - 'I[6S]c' for IPv6 addresses printed as specified by
2137  *       http://tools.ietf.org/html/rfc5952
2138  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2139  *                of the following flags (see string_escape_mem() for the
2140  *                details):
2141  *                  a - ESCAPE_ANY
2142  *                  c - ESCAPE_SPECIAL
2143  *                  h - ESCAPE_HEX
2144  *                  n - ESCAPE_NULL
2145  *                  o - ESCAPE_OCTAL
2146  *                  p - ESCAPE_NP
2147  *                  s - ESCAPE_SPACE
2148  *                By default ESCAPE_ANY_NP is used.
2149  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2150  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2151  *       Options for %pU are:
2152  *         b big endian lower case hex (default)
2153  *         B big endian UPPER case hex
2154  *         l little endian lower case hex
2155  *         L little endian UPPER case hex
2156  *           big endian output byte order is:
2157  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2158  *           little endian output byte order is:
2159  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2160  * - 'V' For a struct va_format which contains a format string * and va_list *,
2161  *       call vsnprintf(->format, *->va_list).
2162  *       Implements a "recursive vsnprintf".
2163  *       Do not use this feature without some mechanism to verify the
2164  *       correctness of the format string and va_list arguments.
2165  * - 'K' For a kernel pointer that should be hidden from unprivileged users
2166  * - 'NF' For a netdev_features_t
2167  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2168  *            a certain separator (' ' by default):
2169  *              C colon
2170  *              D dash
2171  *              N no separator
2172  *            The maximum supported length is 64 bytes of the input. Consider
2173  *            to use print_hex_dump() for the larger input.
2174  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2175  *           (default assumed to be phys_addr_t, passed by reference)
2176  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2177  * - 'D[234]' Same as 'd' but for a struct file
2178  * - 'g' For block_device name (gendisk + partition number)
2179  * - 't[RT][dt][r]' For time and date as represented by:
2180  *      R    struct rtc_time
2181  *      T    time64_t
2182  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2183  *       (legacy clock framework) of the clock
2184  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2185  *        (legacy clock framework) of the clock
2186  * - 'G' For flags to be printed as a collection of symbolic strings that would
2187  *       construct the specific value. Supported flags given by option:
2188  *       p page flags (see struct page) given as pointer to unsigned long
2189  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2190  *       v vma flags (VM_*) given as pointer to unsigned long
2191  * - 'OF[fnpPcCF]'  For a device tree object
2192  *                  Without any optional arguments prints the full_name
2193  *                  f device node full_name
2194  *                  n device node name
2195  *                  p device node phandle
2196  *                  P device node path spec (name + @unit)
2197  *                  F device node flags
2198  *                  c major compatible string
2199  *                  C full compatible string
2200  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2201  *		Without an option prints the full name of the node
2202  *		f full name
2203  *		P node name, including a possible unit address
2204  * - 'x' For printing the address. Equivalent to "%lx".
2205  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2206  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2207  *           or user (u) memory to probe, and:
2208  *              s a string, equivalent to "%s" on direct vsnprintf() use
2209  *
2210  * ** When making changes please also update:
2211  *	Documentation/core-api/printk-formats.rst
2212  *
2213  * Note: The default behaviour (unadorned %p) is to hash the address,
2214  * rendering it useful as a unique identifier.
2215  */
2216 static noinline_for_stack
2217 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2218 	      struct printf_spec spec)
2219 {
2220 	switch (*fmt) {
2221 	case 'S':
2222 	case 's':
2223 		ptr = dereference_symbol_descriptor(ptr);
2224 		/* Fallthrough */
2225 	case 'B':
2226 		return symbol_string(buf, end, ptr, spec, fmt);
2227 	case 'R':
2228 	case 'r':
2229 		return resource_string(buf, end, ptr, spec, fmt);
2230 	case 'h':
2231 		return hex_string(buf, end, ptr, spec, fmt);
2232 	case 'b':
2233 		switch (fmt[1]) {
2234 		case 'l':
2235 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2236 		default:
2237 			return bitmap_string(buf, end, ptr, spec, fmt);
2238 		}
2239 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2240 	case 'm':			/* Contiguous: 000102030405 */
2241 					/* [mM]F (FDDI) */
2242 					/* [mM]R (Reverse order; Bluetooth) */
2243 		return mac_address_string(buf, end, ptr, spec, fmt);
2244 	case 'I':			/* Formatted IP supported
2245 					 * 4:	1.2.3.4
2246 					 * 6:	0001:0203:...:0708
2247 					 * 6c:	1::708 or 1::1.2.3.4
2248 					 */
2249 	case 'i':			/* Contiguous:
2250 					 * 4:	001.002.003.004
2251 					 * 6:   000102...0f
2252 					 */
2253 		return ip_addr_string(buf, end, ptr, spec, fmt);
2254 	case 'E':
2255 		return escaped_string(buf, end, ptr, spec, fmt);
2256 	case 'U':
2257 		return uuid_string(buf, end, ptr, spec, fmt);
2258 	case 'V':
2259 		return va_format(buf, end, ptr, spec, fmt);
2260 	case 'K':
2261 		return restricted_pointer(buf, end, ptr, spec);
2262 	case 'N':
2263 		return netdev_bits(buf, end, ptr, spec, fmt);
2264 	case 'a':
2265 		return address_val(buf, end, ptr, spec, fmt);
2266 	case 'd':
2267 		return dentry_name(buf, end, ptr, spec, fmt);
2268 	case 't':
2269 		return time_and_date(buf, end, ptr, spec, fmt);
2270 	case 'C':
2271 		return clock(buf, end, ptr, spec, fmt);
2272 	case 'D':
2273 		return file_dentry_name(buf, end, ptr, spec, fmt);
2274 #ifdef CONFIG_BLOCK
2275 	case 'g':
2276 		return bdev_name(buf, end, ptr, spec, fmt);
2277 #endif
2278 
2279 	case 'G':
2280 		return flags_string(buf, end, ptr, spec, fmt);
2281 	case 'O':
2282 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2283 	case 'f':
2284 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2285 	case 'x':
2286 		return pointer_string(buf, end, ptr, spec);
2287 	case 'e':
2288 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2289 		if (!IS_ERR(ptr))
2290 			break;
2291 		return err_ptr(buf, end, ptr, spec);
2292 	case 'u':
2293 	case 'k':
2294 		switch (fmt[1]) {
2295 		case 's':
2296 			return string(buf, end, ptr, spec);
2297 		default:
2298 			return error_string(buf, end, "(einval)", spec);
2299 		}
2300 	}
2301 
2302 	/* default is to _not_ leak addresses, hash before printing */
2303 	return ptr_to_id(buf, end, ptr, spec);
2304 }
2305 
2306 /*
2307  * Helper function to decode printf style format.
2308  * Each call decode a token from the format and return the
2309  * number of characters read (or likely the delta where it wants
2310  * to go on the next call).
2311  * The decoded token is returned through the parameters
2312  *
2313  * 'h', 'l', or 'L' for integer fields
2314  * 'z' support added 23/7/1999 S.H.
2315  * 'z' changed to 'Z' --davidm 1/25/99
2316  * 'Z' changed to 'z' --adobriyan 2017-01-25
2317  * 't' added for ptrdiff_t
2318  *
2319  * @fmt: the format string
2320  * @type of the token returned
2321  * @flags: various flags such as +, -, # tokens..
2322  * @field_width: overwritten width
2323  * @base: base of the number (octal, hex, ...)
2324  * @precision: precision of a number
2325  * @qualifier: qualifier of a number (long, size_t, ...)
2326  */
2327 static noinline_for_stack
2328 int format_decode(const char *fmt, struct printf_spec *spec)
2329 {
2330 	const char *start = fmt;
2331 	char qualifier;
2332 
2333 	/* we finished early by reading the field width */
2334 	if (spec->type == FORMAT_TYPE_WIDTH) {
2335 		if (spec->field_width < 0) {
2336 			spec->field_width = -spec->field_width;
2337 			spec->flags |= LEFT;
2338 		}
2339 		spec->type = FORMAT_TYPE_NONE;
2340 		goto precision;
2341 	}
2342 
2343 	/* we finished early by reading the precision */
2344 	if (spec->type == FORMAT_TYPE_PRECISION) {
2345 		if (spec->precision < 0)
2346 			spec->precision = 0;
2347 
2348 		spec->type = FORMAT_TYPE_NONE;
2349 		goto qualifier;
2350 	}
2351 
2352 	/* By default */
2353 	spec->type = FORMAT_TYPE_NONE;
2354 
2355 	for (; *fmt ; ++fmt) {
2356 		if (*fmt == '%')
2357 			break;
2358 	}
2359 
2360 	/* Return the current non-format string */
2361 	if (fmt != start || !*fmt)
2362 		return fmt - start;
2363 
2364 	/* Process flags */
2365 	spec->flags = 0;
2366 
2367 	while (1) { /* this also skips first '%' */
2368 		bool found = true;
2369 
2370 		++fmt;
2371 
2372 		switch (*fmt) {
2373 		case '-': spec->flags |= LEFT;    break;
2374 		case '+': spec->flags |= PLUS;    break;
2375 		case ' ': spec->flags |= SPACE;   break;
2376 		case '#': spec->flags |= SPECIAL; break;
2377 		case '0': spec->flags |= ZEROPAD; break;
2378 		default:  found = false;
2379 		}
2380 
2381 		if (!found)
2382 			break;
2383 	}
2384 
2385 	/* get field width */
2386 	spec->field_width = -1;
2387 
2388 	if (isdigit(*fmt))
2389 		spec->field_width = skip_atoi(&fmt);
2390 	else if (*fmt == '*') {
2391 		/* it's the next argument */
2392 		spec->type = FORMAT_TYPE_WIDTH;
2393 		return ++fmt - start;
2394 	}
2395 
2396 precision:
2397 	/* get the precision */
2398 	spec->precision = -1;
2399 	if (*fmt == '.') {
2400 		++fmt;
2401 		if (isdigit(*fmt)) {
2402 			spec->precision = skip_atoi(&fmt);
2403 			if (spec->precision < 0)
2404 				spec->precision = 0;
2405 		} else if (*fmt == '*') {
2406 			/* it's the next argument */
2407 			spec->type = FORMAT_TYPE_PRECISION;
2408 			return ++fmt - start;
2409 		}
2410 	}
2411 
2412 qualifier:
2413 	/* get the conversion qualifier */
2414 	qualifier = 0;
2415 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2416 	    *fmt == 'z' || *fmt == 't') {
2417 		qualifier = *fmt++;
2418 		if (unlikely(qualifier == *fmt)) {
2419 			if (qualifier == 'l') {
2420 				qualifier = 'L';
2421 				++fmt;
2422 			} else if (qualifier == 'h') {
2423 				qualifier = 'H';
2424 				++fmt;
2425 			}
2426 		}
2427 	}
2428 
2429 	/* default base */
2430 	spec->base = 10;
2431 	switch (*fmt) {
2432 	case 'c':
2433 		spec->type = FORMAT_TYPE_CHAR;
2434 		return ++fmt - start;
2435 
2436 	case 's':
2437 		spec->type = FORMAT_TYPE_STR;
2438 		return ++fmt - start;
2439 
2440 	case 'p':
2441 		spec->type = FORMAT_TYPE_PTR;
2442 		return ++fmt - start;
2443 
2444 	case '%':
2445 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2446 		return ++fmt - start;
2447 
2448 	/* integer number formats - set up the flags and "break" */
2449 	case 'o':
2450 		spec->base = 8;
2451 		break;
2452 
2453 	case 'x':
2454 		spec->flags |= SMALL;
2455 		/* fall through */
2456 
2457 	case 'X':
2458 		spec->base = 16;
2459 		break;
2460 
2461 	case 'd':
2462 	case 'i':
2463 		spec->flags |= SIGN;
2464 	case 'u':
2465 		break;
2466 
2467 	case 'n':
2468 		/*
2469 		 * Since %n poses a greater security risk than
2470 		 * utility, treat it as any other invalid or
2471 		 * unsupported format specifier.
2472 		 */
2473 		/* Fall-through */
2474 
2475 	default:
2476 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2477 		spec->type = FORMAT_TYPE_INVALID;
2478 		return fmt - start;
2479 	}
2480 
2481 	if (qualifier == 'L')
2482 		spec->type = FORMAT_TYPE_LONG_LONG;
2483 	else if (qualifier == 'l') {
2484 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2485 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2486 	} else if (qualifier == 'z') {
2487 		spec->type = FORMAT_TYPE_SIZE_T;
2488 	} else if (qualifier == 't') {
2489 		spec->type = FORMAT_TYPE_PTRDIFF;
2490 	} else if (qualifier == 'H') {
2491 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2492 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2493 	} else if (qualifier == 'h') {
2494 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2495 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2496 	} else {
2497 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2498 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2499 	}
2500 
2501 	return ++fmt - start;
2502 }
2503 
2504 static void
2505 set_field_width(struct printf_spec *spec, int width)
2506 {
2507 	spec->field_width = width;
2508 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2509 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2510 	}
2511 }
2512 
2513 static void
2514 set_precision(struct printf_spec *spec, int prec)
2515 {
2516 	spec->precision = prec;
2517 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2518 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2519 	}
2520 }
2521 
2522 /**
2523  * vsnprintf - Format a string and place it in a buffer
2524  * @buf: The buffer to place the result into
2525  * @size: The size of the buffer, including the trailing null space
2526  * @fmt: The format string to use
2527  * @args: Arguments for the format string
2528  *
2529  * This function generally follows C99 vsnprintf, but has some
2530  * extensions and a few limitations:
2531  *
2532  *  - ``%n`` is unsupported
2533  *  - ``%p*`` is handled by pointer()
2534  *
2535  * See pointer() or Documentation/core-api/printk-formats.rst for more
2536  * extensive description.
2537  *
2538  * **Please update the documentation in both places when making changes**
2539  *
2540  * The return value is the number of characters which would
2541  * be generated for the given input, excluding the trailing
2542  * '\0', as per ISO C99. If you want to have the exact
2543  * number of characters written into @buf as return value
2544  * (not including the trailing '\0'), use vscnprintf(). If the
2545  * return is greater than or equal to @size, the resulting
2546  * string is truncated.
2547  *
2548  * If you're not already dealing with a va_list consider using snprintf().
2549  */
2550 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2551 {
2552 	unsigned long long num;
2553 	char *str, *end;
2554 	struct printf_spec spec = {0};
2555 
2556 	/* Reject out-of-range values early.  Large positive sizes are
2557 	   used for unknown buffer sizes. */
2558 	if (WARN_ON_ONCE(size > INT_MAX))
2559 		return 0;
2560 
2561 	str = buf;
2562 	end = buf + size;
2563 
2564 	/* Make sure end is always >= buf */
2565 	if (end < buf) {
2566 		end = ((void *)-1);
2567 		size = end - buf;
2568 	}
2569 
2570 	while (*fmt) {
2571 		const char *old_fmt = fmt;
2572 		int read = format_decode(fmt, &spec);
2573 
2574 		fmt += read;
2575 
2576 		switch (spec.type) {
2577 		case FORMAT_TYPE_NONE: {
2578 			int copy = read;
2579 			if (str < end) {
2580 				if (copy > end - str)
2581 					copy = end - str;
2582 				memcpy(str, old_fmt, copy);
2583 			}
2584 			str += read;
2585 			break;
2586 		}
2587 
2588 		case FORMAT_TYPE_WIDTH:
2589 			set_field_width(&spec, va_arg(args, int));
2590 			break;
2591 
2592 		case FORMAT_TYPE_PRECISION:
2593 			set_precision(&spec, va_arg(args, int));
2594 			break;
2595 
2596 		case FORMAT_TYPE_CHAR: {
2597 			char c;
2598 
2599 			if (!(spec.flags & LEFT)) {
2600 				while (--spec.field_width > 0) {
2601 					if (str < end)
2602 						*str = ' ';
2603 					++str;
2604 
2605 				}
2606 			}
2607 			c = (unsigned char) va_arg(args, int);
2608 			if (str < end)
2609 				*str = c;
2610 			++str;
2611 			while (--spec.field_width > 0) {
2612 				if (str < end)
2613 					*str = ' ';
2614 				++str;
2615 			}
2616 			break;
2617 		}
2618 
2619 		case FORMAT_TYPE_STR:
2620 			str = string(str, end, va_arg(args, char *), spec);
2621 			break;
2622 
2623 		case FORMAT_TYPE_PTR:
2624 			str = pointer(fmt, str, end, va_arg(args, void *),
2625 				      spec);
2626 			while (isalnum(*fmt))
2627 				fmt++;
2628 			break;
2629 
2630 		case FORMAT_TYPE_PERCENT_CHAR:
2631 			if (str < end)
2632 				*str = '%';
2633 			++str;
2634 			break;
2635 
2636 		case FORMAT_TYPE_INVALID:
2637 			/*
2638 			 * Presumably the arguments passed gcc's type
2639 			 * checking, but there is no safe or sane way
2640 			 * for us to continue parsing the format and
2641 			 * fetching from the va_list; the remaining
2642 			 * specifiers and arguments would be out of
2643 			 * sync.
2644 			 */
2645 			goto out;
2646 
2647 		default:
2648 			switch (spec.type) {
2649 			case FORMAT_TYPE_LONG_LONG:
2650 				num = va_arg(args, long long);
2651 				break;
2652 			case FORMAT_TYPE_ULONG:
2653 				num = va_arg(args, unsigned long);
2654 				break;
2655 			case FORMAT_TYPE_LONG:
2656 				num = va_arg(args, long);
2657 				break;
2658 			case FORMAT_TYPE_SIZE_T:
2659 				if (spec.flags & SIGN)
2660 					num = va_arg(args, ssize_t);
2661 				else
2662 					num = va_arg(args, size_t);
2663 				break;
2664 			case FORMAT_TYPE_PTRDIFF:
2665 				num = va_arg(args, ptrdiff_t);
2666 				break;
2667 			case FORMAT_TYPE_UBYTE:
2668 				num = (unsigned char) va_arg(args, int);
2669 				break;
2670 			case FORMAT_TYPE_BYTE:
2671 				num = (signed char) va_arg(args, int);
2672 				break;
2673 			case FORMAT_TYPE_USHORT:
2674 				num = (unsigned short) va_arg(args, int);
2675 				break;
2676 			case FORMAT_TYPE_SHORT:
2677 				num = (short) va_arg(args, int);
2678 				break;
2679 			case FORMAT_TYPE_INT:
2680 				num = (int) va_arg(args, int);
2681 				break;
2682 			default:
2683 				num = va_arg(args, unsigned int);
2684 			}
2685 
2686 			str = number(str, end, num, spec);
2687 		}
2688 	}
2689 
2690 out:
2691 	if (size > 0) {
2692 		if (str < end)
2693 			*str = '\0';
2694 		else
2695 			end[-1] = '\0';
2696 	}
2697 
2698 	/* the trailing null byte doesn't count towards the total */
2699 	return str-buf;
2700 
2701 }
2702 EXPORT_SYMBOL(vsnprintf);
2703 
2704 /**
2705  * vscnprintf - Format a string and place it in a buffer
2706  * @buf: The buffer to place the result into
2707  * @size: The size of the buffer, including the trailing null space
2708  * @fmt: The format string to use
2709  * @args: Arguments for the format string
2710  *
2711  * The return value is the number of characters which have been written into
2712  * the @buf not including the trailing '\0'. If @size is == 0 the function
2713  * returns 0.
2714  *
2715  * If you're not already dealing with a va_list consider using scnprintf().
2716  *
2717  * See the vsnprintf() documentation for format string extensions over C99.
2718  */
2719 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2720 {
2721 	int i;
2722 
2723 	i = vsnprintf(buf, size, fmt, args);
2724 
2725 	if (likely(i < size))
2726 		return i;
2727 	if (size != 0)
2728 		return size - 1;
2729 	return 0;
2730 }
2731 EXPORT_SYMBOL(vscnprintf);
2732 
2733 /**
2734  * snprintf - Format a string and place it in a buffer
2735  * @buf: The buffer to place the result into
2736  * @size: The size of the buffer, including the trailing null space
2737  * @fmt: The format string to use
2738  * @...: Arguments for the format string
2739  *
2740  * The return value is the number of characters which would be
2741  * generated for the given input, excluding the trailing null,
2742  * as per ISO C99.  If the return is greater than or equal to
2743  * @size, the resulting string is truncated.
2744  *
2745  * See the vsnprintf() documentation for format string extensions over C99.
2746  */
2747 int snprintf(char *buf, size_t size, const char *fmt, ...)
2748 {
2749 	va_list args;
2750 	int i;
2751 
2752 	va_start(args, fmt);
2753 	i = vsnprintf(buf, size, fmt, args);
2754 	va_end(args);
2755 
2756 	return i;
2757 }
2758 EXPORT_SYMBOL(snprintf);
2759 
2760 /**
2761  * scnprintf - Format a string and place it in a buffer
2762  * @buf: The buffer to place the result into
2763  * @size: The size of the buffer, including the trailing null space
2764  * @fmt: The format string to use
2765  * @...: Arguments for the format string
2766  *
2767  * The return value is the number of characters written into @buf not including
2768  * the trailing '\0'. If @size is == 0 the function returns 0.
2769  */
2770 
2771 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2772 {
2773 	va_list args;
2774 	int i;
2775 
2776 	va_start(args, fmt);
2777 	i = vscnprintf(buf, size, fmt, args);
2778 	va_end(args);
2779 
2780 	return i;
2781 }
2782 EXPORT_SYMBOL(scnprintf);
2783 
2784 /**
2785  * vsprintf - Format a string and place it in a buffer
2786  * @buf: The buffer to place the result into
2787  * @fmt: The format string to use
2788  * @args: Arguments for the format string
2789  *
2790  * The function returns the number of characters written
2791  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2792  * buffer overflows.
2793  *
2794  * If you're not already dealing with a va_list consider using sprintf().
2795  *
2796  * See the vsnprintf() documentation for format string extensions over C99.
2797  */
2798 int vsprintf(char *buf, const char *fmt, va_list args)
2799 {
2800 	return vsnprintf(buf, INT_MAX, fmt, args);
2801 }
2802 EXPORT_SYMBOL(vsprintf);
2803 
2804 /**
2805  * sprintf - Format a string and place it in a buffer
2806  * @buf: The buffer to place the result into
2807  * @fmt: The format string to use
2808  * @...: Arguments for the format string
2809  *
2810  * The function returns the number of characters written
2811  * into @buf. Use snprintf() or scnprintf() in order to avoid
2812  * buffer overflows.
2813  *
2814  * See the vsnprintf() documentation for format string extensions over C99.
2815  */
2816 int sprintf(char *buf, const char *fmt, ...)
2817 {
2818 	va_list args;
2819 	int i;
2820 
2821 	va_start(args, fmt);
2822 	i = vsnprintf(buf, INT_MAX, fmt, args);
2823 	va_end(args);
2824 
2825 	return i;
2826 }
2827 EXPORT_SYMBOL(sprintf);
2828 
2829 #ifdef CONFIG_BINARY_PRINTF
2830 /*
2831  * bprintf service:
2832  * vbin_printf() - VA arguments to binary data
2833  * bstr_printf() - Binary data to text string
2834  */
2835 
2836 /**
2837  * vbin_printf - Parse a format string and place args' binary value in a buffer
2838  * @bin_buf: The buffer to place args' binary value
2839  * @size: The size of the buffer(by words(32bits), not characters)
2840  * @fmt: The format string to use
2841  * @args: Arguments for the format string
2842  *
2843  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2844  * is skipped.
2845  *
2846  * The return value is the number of words(32bits) which would be generated for
2847  * the given input.
2848  *
2849  * NOTE:
2850  * If the return value is greater than @size, the resulting bin_buf is NOT
2851  * valid for bstr_printf().
2852  */
2853 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2854 {
2855 	struct printf_spec spec = {0};
2856 	char *str, *end;
2857 	int width;
2858 
2859 	str = (char *)bin_buf;
2860 	end = (char *)(bin_buf + size);
2861 
2862 #define save_arg(type)							\
2863 ({									\
2864 	unsigned long long value;					\
2865 	if (sizeof(type) == 8) {					\
2866 		unsigned long long val8;				\
2867 		str = PTR_ALIGN(str, sizeof(u32));			\
2868 		val8 = va_arg(args, unsigned long long);		\
2869 		if (str + sizeof(type) <= end) {			\
2870 			*(u32 *)str = *(u32 *)&val8;			\
2871 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
2872 		}							\
2873 		value = val8;						\
2874 	} else {							\
2875 		unsigned int val4;					\
2876 		str = PTR_ALIGN(str, sizeof(type));			\
2877 		val4 = va_arg(args, int);				\
2878 		if (str + sizeof(type) <= end)				\
2879 			*(typeof(type) *)str = (type)(long)val4;	\
2880 		value = (unsigned long long)val4;			\
2881 	}								\
2882 	str += sizeof(type);						\
2883 	value;								\
2884 })
2885 
2886 	while (*fmt) {
2887 		int read = format_decode(fmt, &spec);
2888 
2889 		fmt += read;
2890 
2891 		switch (spec.type) {
2892 		case FORMAT_TYPE_NONE:
2893 		case FORMAT_TYPE_PERCENT_CHAR:
2894 			break;
2895 		case FORMAT_TYPE_INVALID:
2896 			goto out;
2897 
2898 		case FORMAT_TYPE_WIDTH:
2899 		case FORMAT_TYPE_PRECISION:
2900 			width = (int)save_arg(int);
2901 			/* Pointers may require the width */
2902 			if (*fmt == 'p')
2903 				set_field_width(&spec, width);
2904 			break;
2905 
2906 		case FORMAT_TYPE_CHAR:
2907 			save_arg(char);
2908 			break;
2909 
2910 		case FORMAT_TYPE_STR: {
2911 			const char *save_str = va_arg(args, char *);
2912 			const char *err_msg;
2913 			size_t len;
2914 
2915 			err_msg = check_pointer_msg(save_str);
2916 			if (err_msg)
2917 				save_str = err_msg;
2918 
2919 			len = strlen(save_str) + 1;
2920 			if (str + len < end)
2921 				memcpy(str, save_str, len);
2922 			str += len;
2923 			break;
2924 		}
2925 
2926 		case FORMAT_TYPE_PTR:
2927 			/* Dereferenced pointers must be done now */
2928 			switch (*fmt) {
2929 			/* Dereference of functions is still OK */
2930 			case 'S':
2931 			case 's':
2932 			case 'x':
2933 			case 'K':
2934 			case 'e':
2935 				save_arg(void *);
2936 				break;
2937 			default:
2938 				if (!isalnum(*fmt)) {
2939 					save_arg(void *);
2940 					break;
2941 				}
2942 				str = pointer(fmt, str, end, va_arg(args, void *),
2943 					      spec);
2944 				if (str + 1 < end)
2945 					*str++ = '\0';
2946 				else
2947 					end[-1] = '\0'; /* Must be nul terminated */
2948 			}
2949 			/* skip all alphanumeric pointer suffixes */
2950 			while (isalnum(*fmt))
2951 				fmt++;
2952 			break;
2953 
2954 		default:
2955 			switch (spec.type) {
2956 
2957 			case FORMAT_TYPE_LONG_LONG:
2958 				save_arg(long long);
2959 				break;
2960 			case FORMAT_TYPE_ULONG:
2961 			case FORMAT_TYPE_LONG:
2962 				save_arg(unsigned long);
2963 				break;
2964 			case FORMAT_TYPE_SIZE_T:
2965 				save_arg(size_t);
2966 				break;
2967 			case FORMAT_TYPE_PTRDIFF:
2968 				save_arg(ptrdiff_t);
2969 				break;
2970 			case FORMAT_TYPE_UBYTE:
2971 			case FORMAT_TYPE_BYTE:
2972 				save_arg(char);
2973 				break;
2974 			case FORMAT_TYPE_USHORT:
2975 			case FORMAT_TYPE_SHORT:
2976 				save_arg(short);
2977 				break;
2978 			default:
2979 				save_arg(int);
2980 			}
2981 		}
2982 	}
2983 
2984 out:
2985 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2986 #undef save_arg
2987 }
2988 EXPORT_SYMBOL_GPL(vbin_printf);
2989 
2990 /**
2991  * bstr_printf - Format a string from binary arguments and place it in a buffer
2992  * @buf: The buffer to place the result into
2993  * @size: The size of the buffer, including the trailing null space
2994  * @fmt: The format string to use
2995  * @bin_buf: Binary arguments for the format string
2996  *
2997  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2998  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2999  * a binary buffer that generated by vbin_printf.
3000  *
3001  * The format follows C99 vsnprintf, but has some extensions:
3002  *  see vsnprintf comment for details.
3003  *
3004  * The return value is the number of characters which would
3005  * be generated for the given input, excluding the trailing
3006  * '\0', as per ISO C99. If you want to have the exact
3007  * number of characters written into @buf as return value
3008  * (not including the trailing '\0'), use vscnprintf(). If the
3009  * return is greater than or equal to @size, the resulting
3010  * string is truncated.
3011  */
3012 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3013 {
3014 	struct printf_spec spec = {0};
3015 	char *str, *end;
3016 	const char *args = (const char *)bin_buf;
3017 
3018 	if (WARN_ON_ONCE(size > INT_MAX))
3019 		return 0;
3020 
3021 	str = buf;
3022 	end = buf + size;
3023 
3024 #define get_arg(type)							\
3025 ({									\
3026 	typeof(type) value;						\
3027 	if (sizeof(type) == 8) {					\
3028 		args = PTR_ALIGN(args, sizeof(u32));			\
3029 		*(u32 *)&value = *(u32 *)args;				\
3030 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3031 	} else {							\
3032 		args = PTR_ALIGN(args, sizeof(type));			\
3033 		value = *(typeof(type) *)args;				\
3034 	}								\
3035 	args += sizeof(type);						\
3036 	value;								\
3037 })
3038 
3039 	/* Make sure end is always >= buf */
3040 	if (end < buf) {
3041 		end = ((void *)-1);
3042 		size = end - buf;
3043 	}
3044 
3045 	while (*fmt) {
3046 		const char *old_fmt = fmt;
3047 		int read = format_decode(fmt, &spec);
3048 
3049 		fmt += read;
3050 
3051 		switch (spec.type) {
3052 		case FORMAT_TYPE_NONE: {
3053 			int copy = read;
3054 			if (str < end) {
3055 				if (copy > end - str)
3056 					copy = end - str;
3057 				memcpy(str, old_fmt, copy);
3058 			}
3059 			str += read;
3060 			break;
3061 		}
3062 
3063 		case FORMAT_TYPE_WIDTH:
3064 			set_field_width(&spec, get_arg(int));
3065 			break;
3066 
3067 		case FORMAT_TYPE_PRECISION:
3068 			set_precision(&spec, get_arg(int));
3069 			break;
3070 
3071 		case FORMAT_TYPE_CHAR: {
3072 			char c;
3073 
3074 			if (!(spec.flags & LEFT)) {
3075 				while (--spec.field_width > 0) {
3076 					if (str < end)
3077 						*str = ' ';
3078 					++str;
3079 				}
3080 			}
3081 			c = (unsigned char) get_arg(char);
3082 			if (str < end)
3083 				*str = c;
3084 			++str;
3085 			while (--spec.field_width > 0) {
3086 				if (str < end)
3087 					*str = ' ';
3088 				++str;
3089 			}
3090 			break;
3091 		}
3092 
3093 		case FORMAT_TYPE_STR: {
3094 			const char *str_arg = args;
3095 			args += strlen(str_arg) + 1;
3096 			str = string(str, end, (char *)str_arg, spec);
3097 			break;
3098 		}
3099 
3100 		case FORMAT_TYPE_PTR: {
3101 			bool process = false;
3102 			int copy, len;
3103 			/* Non function dereferences were already done */
3104 			switch (*fmt) {
3105 			case 'S':
3106 			case 's':
3107 			case 'F':
3108 			case 'f':
3109 			case 'x':
3110 			case 'K':
3111 			case 'e':
3112 				process = true;
3113 				break;
3114 			default:
3115 				if (!isalnum(*fmt)) {
3116 					process = true;
3117 					break;
3118 				}
3119 				/* Pointer dereference was already processed */
3120 				if (str < end) {
3121 					len = copy = strlen(args);
3122 					if (copy > end - str)
3123 						copy = end - str;
3124 					memcpy(str, args, copy);
3125 					str += len;
3126 					args += len + 1;
3127 				}
3128 			}
3129 			if (process)
3130 				str = pointer(fmt, str, end, get_arg(void *), spec);
3131 
3132 			while (isalnum(*fmt))
3133 				fmt++;
3134 			break;
3135 		}
3136 
3137 		case FORMAT_TYPE_PERCENT_CHAR:
3138 			if (str < end)
3139 				*str = '%';
3140 			++str;
3141 			break;
3142 
3143 		case FORMAT_TYPE_INVALID:
3144 			goto out;
3145 
3146 		default: {
3147 			unsigned long long num;
3148 
3149 			switch (spec.type) {
3150 
3151 			case FORMAT_TYPE_LONG_LONG:
3152 				num = get_arg(long long);
3153 				break;
3154 			case FORMAT_TYPE_ULONG:
3155 			case FORMAT_TYPE_LONG:
3156 				num = get_arg(unsigned long);
3157 				break;
3158 			case FORMAT_TYPE_SIZE_T:
3159 				num = get_arg(size_t);
3160 				break;
3161 			case FORMAT_TYPE_PTRDIFF:
3162 				num = get_arg(ptrdiff_t);
3163 				break;
3164 			case FORMAT_TYPE_UBYTE:
3165 				num = get_arg(unsigned char);
3166 				break;
3167 			case FORMAT_TYPE_BYTE:
3168 				num = get_arg(signed char);
3169 				break;
3170 			case FORMAT_TYPE_USHORT:
3171 				num = get_arg(unsigned short);
3172 				break;
3173 			case FORMAT_TYPE_SHORT:
3174 				num = get_arg(short);
3175 				break;
3176 			case FORMAT_TYPE_UINT:
3177 				num = get_arg(unsigned int);
3178 				break;
3179 			default:
3180 				num = get_arg(int);
3181 			}
3182 
3183 			str = number(str, end, num, spec);
3184 		} /* default: */
3185 		} /* switch(spec.type) */
3186 	} /* while(*fmt) */
3187 
3188 out:
3189 	if (size > 0) {
3190 		if (str < end)
3191 			*str = '\0';
3192 		else
3193 			end[-1] = '\0';
3194 	}
3195 
3196 #undef get_arg
3197 
3198 	/* the trailing null byte doesn't count towards the total */
3199 	return str - buf;
3200 }
3201 EXPORT_SYMBOL_GPL(bstr_printf);
3202 
3203 /**
3204  * bprintf - Parse a format string and place args' binary value in a buffer
3205  * @bin_buf: The buffer to place args' binary value
3206  * @size: The size of the buffer(by words(32bits), not characters)
3207  * @fmt: The format string to use
3208  * @...: Arguments for the format string
3209  *
3210  * The function returns the number of words(u32) written
3211  * into @bin_buf.
3212  */
3213 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3214 {
3215 	va_list args;
3216 	int ret;
3217 
3218 	va_start(args, fmt);
3219 	ret = vbin_printf(bin_buf, size, fmt, args);
3220 	va_end(args);
3221 
3222 	return ret;
3223 }
3224 EXPORT_SYMBOL_GPL(bprintf);
3225 
3226 #endif /* CONFIG_BINARY_PRINTF */
3227 
3228 /**
3229  * vsscanf - Unformat a buffer into a list of arguments
3230  * @buf:	input buffer
3231  * @fmt:	format of buffer
3232  * @args:	arguments
3233  */
3234 int vsscanf(const char *buf, const char *fmt, va_list args)
3235 {
3236 	const char *str = buf;
3237 	char *next;
3238 	char digit;
3239 	int num = 0;
3240 	u8 qualifier;
3241 	unsigned int base;
3242 	union {
3243 		long long s;
3244 		unsigned long long u;
3245 	} val;
3246 	s16 field_width;
3247 	bool is_sign;
3248 
3249 	while (*fmt) {
3250 		/* skip any white space in format */
3251 		/* white space in format matchs any amount of
3252 		 * white space, including none, in the input.
3253 		 */
3254 		if (isspace(*fmt)) {
3255 			fmt = skip_spaces(++fmt);
3256 			str = skip_spaces(str);
3257 		}
3258 
3259 		/* anything that is not a conversion must match exactly */
3260 		if (*fmt != '%' && *fmt) {
3261 			if (*fmt++ != *str++)
3262 				break;
3263 			continue;
3264 		}
3265 
3266 		if (!*fmt)
3267 			break;
3268 		++fmt;
3269 
3270 		/* skip this conversion.
3271 		 * advance both strings to next white space
3272 		 */
3273 		if (*fmt == '*') {
3274 			if (!*str)
3275 				break;
3276 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3277 				/* '%*[' not yet supported, invalid format */
3278 				if (*fmt == '[')
3279 					return num;
3280 				fmt++;
3281 			}
3282 			while (!isspace(*str) && *str)
3283 				str++;
3284 			continue;
3285 		}
3286 
3287 		/* get field width */
3288 		field_width = -1;
3289 		if (isdigit(*fmt)) {
3290 			field_width = skip_atoi(&fmt);
3291 			if (field_width <= 0)
3292 				break;
3293 		}
3294 
3295 		/* get conversion qualifier */
3296 		qualifier = -1;
3297 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3298 		    *fmt == 'z') {
3299 			qualifier = *fmt++;
3300 			if (unlikely(qualifier == *fmt)) {
3301 				if (qualifier == 'h') {
3302 					qualifier = 'H';
3303 					fmt++;
3304 				} else if (qualifier == 'l') {
3305 					qualifier = 'L';
3306 					fmt++;
3307 				}
3308 			}
3309 		}
3310 
3311 		if (!*fmt)
3312 			break;
3313 
3314 		if (*fmt == 'n') {
3315 			/* return number of characters read so far */
3316 			*va_arg(args, int *) = str - buf;
3317 			++fmt;
3318 			continue;
3319 		}
3320 
3321 		if (!*str)
3322 			break;
3323 
3324 		base = 10;
3325 		is_sign = false;
3326 
3327 		switch (*fmt++) {
3328 		case 'c':
3329 		{
3330 			char *s = (char *)va_arg(args, char*);
3331 			if (field_width == -1)
3332 				field_width = 1;
3333 			do {
3334 				*s++ = *str++;
3335 			} while (--field_width > 0 && *str);
3336 			num++;
3337 		}
3338 		continue;
3339 		case 's':
3340 		{
3341 			char *s = (char *)va_arg(args, char *);
3342 			if (field_width == -1)
3343 				field_width = SHRT_MAX;
3344 			/* first, skip leading white space in buffer */
3345 			str = skip_spaces(str);
3346 
3347 			/* now copy until next white space */
3348 			while (*str && !isspace(*str) && field_width--)
3349 				*s++ = *str++;
3350 			*s = '\0';
3351 			num++;
3352 		}
3353 		continue;
3354 		/*
3355 		 * Warning: This implementation of the '[' conversion specifier
3356 		 * deviates from its glibc counterpart in the following ways:
3357 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3358 		 *     character
3359 		 * (2) It cannot match the closing bracket ']' itself
3360 		 * (3) A field width is required
3361 		 * (4) '%*[' (discard matching input) is currently not supported
3362 		 *
3363 		 * Example usage:
3364 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3365 		 *		buf1, buf2, buf3);
3366 		 * if (ret < 3)
3367 		 *    // etc..
3368 		 */
3369 		case '[':
3370 		{
3371 			char *s = (char *)va_arg(args, char *);
3372 			DECLARE_BITMAP(set, 256) = {0};
3373 			unsigned int len = 0;
3374 			bool negate = (*fmt == '^');
3375 
3376 			/* field width is required */
3377 			if (field_width == -1)
3378 				return num;
3379 
3380 			if (negate)
3381 				++fmt;
3382 
3383 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3384 				set_bit((u8)*fmt, set);
3385 
3386 			/* no ']' or no character set found */
3387 			if (!*fmt || !len)
3388 				return num;
3389 			++fmt;
3390 
3391 			if (negate) {
3392 				bitmap_complement(set, set, 256);
3393 				/* exclude null '\0' byte */
3394 				clear_bit(0, set);
3395 			}
3396 
3397 			/* match must be non-empty */
3398 			if (!test_bit((u8)*str, set))
3399 				return num;
3400 
3401 			while (test_bit((u8)*str, set) && field_width--)
3402 				*s++ = *str++;
3403 			*s = '\0';
3404 			++num;
3405 		}
3406 		continue;
3407 		case 'o':
3408 			base = 8;
3409 			break;
3410 		case 'x':
3411 		case 'X':
3412 			base = 16;
3413 			break;
3414 		case 'i':
3415 			base = 0;
3416 			/* fall through */
3417 		case 'd':
3418 			is_sign = true;
3419 			/* fall through */
3420 		case 'u':
3421 			break;
3422 		case '%':
3423 			/* looking for '%' in str */
3424 			if (*str++ != '%')
3425 				return num;
3426 			continue;
3427 		default:
3428 			/* invalid format; stop here */
3429 			return num;
3430 		}
3431 
3432 		/* have some sort of integer conversion.
3433 		 * first, skip white space in buffer.
3434 		 */
3435 		str = skip_spaces(str);
3436 
3437 		digit = *str;
3438 		if (is_sign && digit == '-')
3439 			digit = *(str + 1);
3440 
3441 		if (!digit
3442 		    || (base == 16 && !isxdigit(digit))
3443 		    || (base == 10 && !isdigit(digit))
3444 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
3445 		    || (base == 0 && !isdigit(digit)))
3446 			break;
3447 
3448 		if (is_sign)
3449 			val.s = qualifier != 'L' ?
3450 				simple_strtol(str, &next, base) :
3451 				simple_strtoll(str, &next, base);
3452 		else
3453 			val.u = qualifier != 'L' ?
3454 				simple_strtoul(str, &next, base) :
3455 				simple_strtoull(str, &next, base);
3456 
3457 		if (field_width > 0 && next - str > field_width) {
3458 			if (base == 0)
3459 				_parse_integer_fixup_radix(str, &base);
3460 			while (next - str > field_width) {
3461 				if (is_sign)
3462 					val.s = div_s64(val.s, base);
3463 				else
3464 					val.u = div_u64(val.u, base);
3465 				--next;
3466 			}
3467 		}
3468 
3469 		switch (qualifier) {
3470 		case 'H':	/* that's 'hh' in format */
3471 			if (is_sign)
3472 				*va_arg(args, signed char *) = val.s;
3473 			else
3474 				*va_arg(args, unsigned char *) = val.u;
3475 			break;
3476 		case 'h':
3477 			if (is_sign)
3478 				*va_arg(args, short *) = val.s;
3479 			else
3480 				*va_arg(args, unsigned short *) = val.u;
3481 			break;
3482 		case 'l':
3483 			if (is_sign)
3484 				*va_arg(args, long *) = val.s;
3485 			else
3486 				*va_arg(args, unsigned long *) = val.u;
3487 			break;
3488 		case 'L':
3489 			if (is_sign)
3490 				*va_arg(args, long long *) = val.s;
3491 			else
3492 				*va_arg(args, unsigned long long *) = val.u;
3493 			break;
3494 		case 'z':
3495 			*va_arg(args, size_t *) = val.u;
3496 			break;
3497 		default:
3498 			if (is_sign)
3499 				*va_arg(args, int *) = val.s;
3500 			else
3501 				*va_arg(args, unsigned int *) = val.u;
3502 			break;
3503 		}
3504 		num++;
3505 
3506 		if (!next)
3507 			break;
3508 		str = next;
3509 	}
3510 
3511 	return num;
3512 }
3513 EXPORT_SYMBOL(vsscanf);
3514 
3515 /**
3516  * sscanf - Unformat a buffer into a list of arguments
3517  * @buf:	input buffer
3518  * @fmt:	formatting of buffer
3519  * @...:	resulting arguments
3520  */
3521 int sscanf(const char *buf, const char *fmt, ...)
3522 {
3523 	va_list args;
3524 	int i;
3525 
3526 	va_start(args, fmt);
3527 	i = vsscanf(buf, fmt, args);
3528 	va_end(args);
3529 
3530 	return i;
3531 }
3532 EXPORT_SYMBOL(sscanf);
3533