xref: /openbmc/linux/lib/vsprintf.c (revision 6342a20e)
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 <linux/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 #include <linux/notifier.h>
45 #ifdef CONFIG_BLOCK
46 #include <linux/blkdev.h>
47 #endif
48 
49 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
50 
51 #include <asm/page.h>		/* for PAGE_SIZE */
52 #include <asm/byteorder.h>	/* cpu_to_le16 */
53 #include <asm/unaligned.h>
54 
55 #include <linux/string_helpers.h>
56 #include "kstrtox.h"
57 
58 /* Disable pointer hashing if requested */
59 bool no_hash_pointers __ro_after_init;
60 EXPORT_SYMBOL_GPL(no_hash_pointers);
61 
62 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
63 {
64 	const char *cp;
65 	unsigned long long result = 0ULL;
66 	size_t prefix_chars;
67 	unsigned int rv;
68 
69 	cp = _parse_integer_fixup_radix(startp, &base);
70 	prefix_chars = cp - startp;
71 	if (prefix_chars < max_chars) {
72 		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
73 		/* FIXME */
74 		cp += (rv & ~KSTRTOX_OVERFLOW);
75 	} else {
76 		/* Field too short for prefix + digit, skip over without converting */
77 		cp = startp + max_chars;
78 	}
79 
80 	if (endp)
81 		*endp = (char *)cp;
82 
83 	return result;
84 }
85 
86 /**
87  * simple_strtoull - convert a string to an unsigned long long
88  * @cp: The start of the string
89  * @endp: A pointer to the end of the parsed string will be placed here
90  * @base: The number base to use
91  *
92  * This function has caveats. Please use kstrtoull instead.
93  */
94 noinline
95 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
96 {
97 	return simple_strntoull(cp, INT_MAX, endp, base);
98 }
99 EXPORT_SYMBOL(simple_strtoull);
100 
101 /**
102  * simple_strtoul - convert a string to an unsigned long
103  * @cp: The start of the string
104  * @endp: A pointer to the end of the parsed string will be placed here
105  * @base: The number base to use
106  *
107  * This function has caveats. Please use kstrtoul instead.
108  */
109 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
110 {
111 	return simple_strtoull(cp, endp, base);
112 }
113 EXPORT_SYMBOL(simple_strtoul);
114 
115 /**
116  * simple_strtol - convert a string to a signed long
117  * @cp: The start of the string
118  * @endp: A pointer to the end of the parsed string will be placed here
119  * @base: The number base to use
120  *
121  * This function has caveats. Please use kstrtol instead.
122  */
123 long simple_strtol(const char *cp, char **endp, unsigned int base)
124 {
125 	if (*cp == '-')
126 		return -simple_strtoul(cp + 1, endp, base);
127 
128 	return simple_strtoul(cp, endp, base);
129 }
130 EXPORT_SYMBOL(simple_strtol);
131 
132 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
133 				 unsigned int base)
134 {
135 	/*
136 	 * simple_strntoull() safely handles receiving max_chars==0 in the
137 	 * case cp[0] == '-' && max_chars == 1.
138 	 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
139 	 * and the content of *cp is irrelevant.
140 	 */
141 	if (*cp == '-' && max_chars > 0)
142 		return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
143 
144 	return simple_strntoull(cp, max_chars, endp, base);
145 }
146 
147 /**
148  * simple_strtoll - convert a string to a signed long long
149  * @cp: The start of the string
150  * @endp: A pointer to the end of the parsed string will be placed here
151  * @base: The number base to use
152  *
153  * This function has caveats. Please use kstrtoll instead.
154  */
155 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
156 {
157 	return simple_strntoll(cp, INT_MAX, endp, base);
158 }
159 EXPORT_SYMBOL(simple_strtoll);
160 
161 static noinline_for_stack
162 int skip_atoi(const char **s)
163 {
164 	int i = 0;
165 
166 	do {
167 		i = i*10 + *((*s)++) - '0';
168 	} while (isdigit(**s));
169 
170 	return i;
171 }
172 
173 /*
174  * Decimal conversion is by far the most typical, and is used for
175  * /proc and /sys data. This directly impacts e.g. top performance
176  * with many processes running. We optimize it for speed by emitting
177  * two characters at a time, using a 200 byte lookup table. This
178  * roughly halves the number of multiplications compared to computing
179  * the digits one at a time. Implementation strongly inspired by the
180  * previous version, which in turn used ideas described at
181  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
182  * from the author, Douglas W. Jones).
183  *
184  * It turns out there is precisely one 26 bit fixed-point
185  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
186  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
187  * range happens to be somewhat larger (x <= 1073741898), but that's
188  * irrelevant for our purpose.
189  *
190  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
191  * need a 32x32->64 bit multiply, so we simply use the same constant.
192  *
193  * For dividing a number in the range [100, 10^4-1] by 100, there are
194  * several options. The simplest is (x * 0x147b) >> 19, which is valid
195  * for all x <= 43698.
196  */
197 
198 static const u16 decpair[100] = {
199 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
200 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
201 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
202 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
203 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
204 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
205 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
206 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
207 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
208 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
209 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
210 #undef _
211 };
212 
213 /*
214  * This will print a single '0' even if r == 0, since we would
215  * immediately jump to out_r where two 0s would be written but only
216  * one of them accounted for in buf. This is needed by ip4_string
217  * below. All other callers pass a non-zero value of r.
218 */
219 static noinline_for_stack
220 char *put_dec_trunc8(char *buf, unsigned r)
221 {
222 	unsigned q;
223 
224 	/* 1 <= r < 10^8 */
225 	if (r < 100)
226 		goto out_r;
227 
228 	/* 100 <= r < 10^8 */
229 	q = (r * (u64)0x28f5c29) >> 32;
230 	*((u16 *)buf) = decpair[r - 100*q];
231 	buf += 2;
232 
233 	/* 1 <= q < 10^6 */
234 	if (q < 100)
235 		goto out_q;
236 
237 	/*  100 <= q < 10^6 */
238 	r = (q * (u64)0x28f5c29) >> 32;
239 	*((u16 *)buf) = decpair[q - 100*r];
240 	buf += 2;
241 
242 	/* 1 <= r < 10^4 */
243 	if (r < 100)
244 		goto out_r;
245 
246 	/* 100 <= r < 10^4 */
247 	q = (r * 0x147b) >> 19;
248 	*((u16 *)buf) = decpair[r - 100*q];
249 	buf += 2;
250 out_q:
251 	/* 1 <= q < 100 */
252 	r = q;
253 out_r:
254 	/* 1 <= r < 100 */
255 	*((u16 *)buf) = decpair[r];
256 	buf += r < 10 ? 1 : 2;
257 	return buf;
258 }
259 
260 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
261 static noinline_for_stack
262 char *put_dec_full8(char *buf, unsigned r)
263 {
264 	unsigned q;
265 
266 	/* 0 <= r < 10^8 */
267 	q = (r * (u64)0x28f5c29) >> 32;
268 	*((u16 *)buf) = decpair[r - 100*q];
269 	buf += 2;
270 
271 	/* 0 <= q < 10^6 */
272 	r = (q * (u64)0x28f5c29) >> 32;
273 	*((u16 *)buf) = decpair[q - 100*r];
274 	buf += 2;
275 
276 	/* 0 <= r < 10^4 */
277 	q = (r * 0x147b) >> 19;
278 	*((u16 *)buf) = decpair[r - 100*q];
279 	buf += 2;
280 
281 	/* 0 <= q < 100 */
282 	*((u16 *)buf) = decpair[q];
283 	buf += 2;
284 	return buf;
285 }
286 
287 static noinline_for_stack
288 char *put_dec(char *buf, unsigned long long n)
289 {
290 	if (n >= 100*1000*1000)
291 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
292 	/* 1 <= n <= 1.6e11 */
293 	if (n >= 100*1000*1000)
294 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
295 	/* 1 <= n < 1e8 */
296 	return put_dec_trunc8(buf, n);
297 }
298 
299 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
300 
301 static void
302 put_dec_full4(char *buf, unsigned r)
303 {
304 	unsigned q;
305 
306 	/* 0 <= r < 10^4 */
307 	q = (r * 0x147b) >> 19;
308 	*((u16 *)buf) = decpair[r - 100*q];
309 	buf += 2;
310 	/* 0 <= q < 100 */
311 	*((u16 *)buf) = decpair[q];
312 }
313 
314 /*
315  * Call put_dec_full4 on x % 10000, return x / 10000.
316  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
317  * holds for all x < 1,128,869,999.  The largest value this
318  * helper will ever be asked to convert is 1,125,520,955.
319  * (second call in the put_dec code, assuming n is all-ones).
320  */
321 static noinline_for_stack
322 unsigned put_dec_helper4(char *buf, unsigned x)
323 {
324         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
325 
326         put_dec_full4(buf, x - q * 10000);
327         return q;
328 }
329 
330 /* Based on code by Douglas W. Jones found at
331  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
332  * (with permission from the author).
333  * Performs no 64-bit division and hence should be fast on 32-bit machines.
334  */
335 static
336 char *put_dec(char *buf, unsigned long long n)
337 {
338 	uint32_t d3, d2, d1, q, h;
339 
340 	if (n < 100*1000*1000)
341 		return put_dec_trunc8(buf, n);
342 
343 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
344 	h   = (n >> 32);
345 	d2  = (h      ) & 0xffff;
346 	d3  = (h >> 16); /* implicit "& 0xffff" */
347 
348 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
349 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
350 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
351 	q = put_dec_helper4(buf, q);
352 
353 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
354 	q = put_dec_helper4(buf+4, q);
355 
356 	q += 4749 * d3 + 42 * d2;
357 	q = put_dec_helper4(buf+8, q);
358 
359 	q += 281 * d3;
360 	buf += 12;
361 	if (q)
362 		buf = put_dec_trunc8(buf, q);
363 	else while (buf[-1] == '0')
364 		--buf;
365 
366 	return buf;
367 }
368 
369 #endif
370 
371 /*
372  * Convert passed number to decimal string.
373  * Returns the length of string.  On buffer overflow, returns 0.
374  *
375  * If speed is not important, use snprintf(). It's easy to read the code.
376  */
377 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
378 {
379 	/* put_dec requires 2-byte alignment of the buffer. */
380 	char tmp[sizeof(num) * 3] __aligned(2);
381 	int idx, len;
382 
383 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
384 	if (num <= 9) {
385 		tmp[0] = '0' + num;
386 		len = 1;
387 	} else {
388 		len = put_dec(tmp, num) - tmp;
389 	}
390 
391 	if (len > size || width > size)
392 		return 0;
393 
394 	if (width > len) {
395 		width = width - len;
396 		for (idx = 0; idx < width; idx++)
397 			buf[idx] = ' ';
398 	} else {
399 		width = 0;
400 	}
401 
402 	for (idx = 0; idx < len; ++idx)
403 		buf[idx + width] = tmp[len - idx - 1];
404 
405 	return len + width;
406 }
407 
408 #define SIGN	1		/* unsigned/signed, must be 1 */
409 #define LEFT	2		/* left justified */
410 #define PLUS	4		/* show plus */
411 #define SPACE	8		/* space if plus */
412 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
413 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
414 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
415 
416 static_assert(SIGN == 1);
417 static_assert(ZEROPAD == ('0' - ' '));
418 static_assert(SMALL == ('a' ^ 'A'));
419 
420 enum format_type {
421 	FORMAT_TYPE_NONE, /* Just a string part */
422 	FORMAT_TYPE_WIDTH,
423 	FORMAT_TYPE_PRECISION,
424 	FORMAT_TYPE_CHAR,
425 	FORMAT_TYPE_STR,
426 	FORMAT_TYPE_PTR,
427 	FORMAT_TYPE_PERCENT_CHAR,
428 	FORMAT_TYPE_INVALID,
429 	FORMAT_TYPE_LONG_LONG,
430 	FORMAT_TYPE_ULONG,
431 	FORMAT_TYPE_LONG,
432 	FORMAT_TYPE_UBYTE,
433 	FORMAT_TYPE_BYTE,
434 	FORMAT_TYPE_USHORT,
435 	FORMAT_TYPE_SHORT,
436 	FORMAT_TYPE_UINT,
437 	FORMAT_TYPE_INT,
438 	FORMAT_TYPE_SIZE_T,
439 	FORMAT_TYPE_PTRDIFF
440 };
441 
442 struct printf_spec {
443 	unsigned int	type:8;		/* format_type enum */
444 	signed int	field_width:24;	/* width of output field */
445 	unsigned int	flags:8;	/* flags to number() */
446 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
447 	signed int	precision:16;	/* # of digits/chars */
448 } __packed;
449 static_assert(sizeof(struct printf_spec) == 8);
450 
451 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
452 #define PRECISION_MAX ((1 << 15) - 1)
453 
454 static noinline_for_stack
455 char *number(char *buf, char *end, unsigned long long num,
456 	     struct printf_spec spec)
457 {
458 	/* put_dec requires 2-byte alignment of the buffer. */
459 	char tmp[3 * sizeof(num)] __aligned(2);
460 	char sign;
461 	char locase;
462 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
463 	int i;
464 	bool is_zero = num == 0LL;
465 	int field_width = spec.field_width;
466 	int precision = spec.precision;
467 
468 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
469 	 * produces same digits or (maybe lowercased) letters */
470 	locase = (spec.flags & SMALL);
471 	if (spec.flags & LEFT)
472 		spec.flags &= ~ZEROPAD;
473 	sign = 0;
474 	if (spec.flags & SIGN) {
475 		if ((signed long long)num < 0) {
476 			sign = '-';
477 			num = -(signed long long)num;
478 			field_width--;
479 		} else if (spec.flags & PLUS) {
480 			sign = '+';
481 			field_width--;
482 		} else if (spec.flags & SPACE) {
483 			sign = ' ';
484 			field_width--;
485 		}
486 	}
487 	if (need_pfx) {
488 		if (spec.base == 16)
489 			field_width -= 2;
490 		else if (!is_zero)
491 			field_width--;
492 	}
493 
494 	/* generate full string in tmp[], in reverse order */
495 	i = 0;
496 	if (num < spec.base)
497 		tmp[i++] = hex_asc_upper[num] | locase;
498 	else if (spec.base != 10) { /* 8 or 16 */
499 		int mask = spec.base - 1;
500 		int shift = 3;
501 
502 		if (spec.base == 16)
503 			shift = 4;
504 		do {
505 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
506 			num >>= shift;
507 		} while (num);
508 	} else { /* base 10 */
509 		i = put_dec(tmp, num) - tmp;
510 	}
511 
512 	/* printing 100 using %2d gives "100", not "00" */
513 	if (i > precision)
514 		precision = i;
515 	/* leading space padding */
516 	field_width -= precision;
517 	if (!(spec.flags & (ZEROPAD | LEFT))) {
518 		while (--field_width >= 0) {
519 			if (buf < end)
520 				*buf = ' ';
521 			++buf;
522 		}
523 	}
524 	/* sign */
525 	if (sign) {
526 		if (buf < end)
527 			*buf = sign;
528 		++buf;
529 	}
530 	/* "0x" / "0" prefix */
531 	if (need_pfx) {
532 		if (spec.base == 16 || !is_zero) {
533 			if (buf < end)
534 				*buf = '0';
535 			++buf;
536 		}
537 		if (spec.base == 16) {
538 			if (buf < end)
539 				*buf = ('X' | locase);
540 			++buf;
541 		}
542 	}
543 	/* zero or space padding */
544 	if (!(spec.flags & LEFT)) {
545 		char c = ' ' + (spec.flags & ZEROPAD);
546 
547 		while (--field_width >= 0) {
548 			if (buf < end)
549 				*buf = c;
550 			++buf;
551 		}
552 	}
553 	/* hmm even more zero padding? */
554 	while (i <= --precision) {
555 		if (buf < end)
556 			*buf = '0';
557 		++buf;
558 	}
559 	/* actual digits of result */
560 	while (--i >= 0) {
561 		if (buf < end)
562 			*buf = tmp[i];
563 		++buf;
564 	}
565 	/* trailing space padding */
566 	while (--field_width >= 0) {
567 		if (buf < end)
568 			*buf = ' ';
569 		++buf;
570 	}
571 
572 	return buf;
573 }
574 
575 static noinline_for_stack
576 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
577 {
578 	struct printf_spec spec;
579 
580 	spec.type = FORMAT_TYPE_PTR;
581 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
582 	spec.flags = SPECIAL | SMALL | ZEROPAD;
583 	spec.base = 16;
584 	spec.precision = -1;
585 
586 	return number(buf, end, num, spec);
587 }
588 
589 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
590 {
591 	size_t size;
592 	if (buf >= end)	/* nowhere to put anything */
593 		return;
594 	size = end - buf;
595 	if (size <= spaces) {
596 		memset(buf, ' ', size);
597 		return;
598 	}
599 	if (len) {
600 		if (len > size - spaces)
601 			len = size - spaces;
602 		memmove(buf + spaces, buf, len);
603 	}
604 	memset(buf, ' ', spaces);
605 }
606 
607 /*
608  * Handle field width padding for a string.
609  * @buf: current buffer position
610  * @n: length of string
611  * @end: end of output buffer
612  * @spec: for field width and flags
613  * Returns: new buffer position after padding.
614  */
615 static noinline_for_stack
616 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
617 {
618 	unsigned spaces;
619 
620 	if (likely(n >= spec.field_width))
621 		return buf;
622 	/* we want to pad the sucker */
623 	spaces = spec.field_width - n;
624 	if (!(spec.flags & LEFT)) {
625 		move_right(buf - n, end, n, spaces);
626 		return buf + spaces;
627 	}
628 	while (spaces--) {
629 		if (buf < end)
630 			*buf = ' ';
631 		++buf;
632 	}
633 	return buf;
634 }
635 
636 /* Handle string from a well known address. */
637 static char *string_nocheck(char *buf, char *end, const char *s,
638 			    struct printf_spec spec)
639 {
640 	int len = 0;
641 	int lim = spec.precision;
642 
643 	while (lim--) {
644 		char c = *s++;
645 		if (!c)
646 			break;
647 		if (buf < end)
648 			*buf = c;
649 		++buf;
650 		++len;
651 	}
652 	return widen_string(buf, len, end, spec);
653 }
654 
655 static char *err_ptr(char *buf, char *end, void *ptr,
656 		     struct printf_spec spec)
657 {
658 	int err = PTR_ERR(ptr);
659 	const char *sym = errname(err);
660 
661 	if (sym)
662 		return string_nocheck(buf, end, sym, spec);
663 
664 	/*
665 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
666 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
667 	 * printing it as its decimal representation.
668 	 */
669 	spec.flags |= SIGN;
670 	spec.base = 10;
671 	return number(buf, end, err, spec);
672 }
673 
674 /* Be careful: error messages must fit into the given buffer. */
675 static char *error_string(char *buf, char *end, const char *s,
676 			  struct printf_spec spec)
677 {
678 	/*
679 	 * Hard limit to avoid a completely insane messages. It actually
680 	 * works pretty well because most error messages are in
681 	 * the many pointer format modifiers.
682 	 */
683 	if (spec.precision == -1)
684 		spec.precision = 2 * sizeof(void *);
685 
686 	return string_nocheck(buf, end, s, spec);
687 }
688 
689 /*
690  * Do not call any complex external code here. Nested printk()/vsprintf()
691  * might cause infinite loops. Failures might break printk() and would
692  * be hard to debug.
693  */
694 static const char *check_pointer_msg(const void *ptr)
695 {
696 	if (!ptr)
697 		return "(null)";
698 
699 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
700 		return "(efault)";
701 
702 	return NULL;
703 }
704 
705 static int check_pointer(char **buf, char *end, const void *ptr,
706 			 struct printf_spec spec)
707 {
708 	const char *err_msg;
709 
710 	err_msg = check_pointer_msg(ptr);
711 	if (err_msg) {
712 		*buf = error_string(*buf, end, err_msg, spec);
713 		return -EFAULT;
714 	}
715 
716 	return 0;
717 }
718 
719 static noinline_for_stack
720 char *string(char *buf, char *end, const char *s,
721 	     struct printf_spec spec)
722 {
723 	if (check_pointer(&buf, end, s, spec))
724 		return buf;
725 
726 	return string_nocheck(buf, end, s, spec);
727 }
728 
729 static char *pointer_string(char *buf, char *end,
730 			    const void *ptr,
731 			    struct printf_spec spec)
732 {
733 	spec.base = 16;
734 	spec.flags |= SMALL;
735 	if (spec.field_width == -1) {
736 		spec.field_width = 2 * sizeof(ptr);
737 		spec.flags |= ZEROPAD;
738 	}
739 
740 	return number(buf, end, (unsigned long int)ptr, spec);
741 }
742 
743 /* Make pointers available for printing early in the boot sequence. */
744 static int debug_boot_weak_hash __ro_after_init;
745 
746 static int __init debug_boot_weak_hash_enable(char *str)
747 {
748 	debug_boot_weak_hash = 1;
749 	pr_info("debug_boot_weak_hash enabled\n");
750 	return 0;
751 }
752 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
753 
754 static bool filled_random_ptr_key __read_mostly;
755 static siphash_key_t ptr_key __read_mostly;
756 
757 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
758 {
759 	get_random_bytes(&ptr_key, sizeof(ptr_key));
760 
761 	/* Pairs with smp_rmb() before reading ptr_key. */
762 	smp_wmb();
763 	WRITE_ONCE(filled_random_ptr_key, true);
764 	return NOTIFY_DONE;
765 }
766 
767 static int __init vsprintf_init_hashval(void)
768 {
769 	static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
770 	execute_with_initialized_rng(&fill_ptr_key_nb);
771 	return 0;
772 }
773 subsys_initcall(vsprintf_init_hashval)
774 
775 /* Maps a pointer to a 32 bit unique identifier. */
776 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
777 {
778 	unsigned long hashval;
779 
780 	if (!READ_ONCE(filled_random_ptr_key))
781 		return -EBUSY;
782 
783 	/* Pairs with smp_wmb() after writing ptr_key. */
784 	smp_rmb();
785 
786 #ifdef CONFIG_64BIT
787 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
788 	/*
789 	 * Mask off the first 32 bits, this makes explicit that we have
790 	 * modified the address (and 32 bits is plenty for a unique ID).
791 	 */
792 	hashval = hashval & 0xffffffff;
793 #else
794 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
795 #endif
796 	*hashval_out = hashval;
797 	return 0;
798 }
799 
800 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
801 {
802 	return __ptr_to_hashval(ptr, hashval_out);
803 }
804 
805 static char *ptr_to_id(char *buf, char *end, const void *ptr,
806 		       struct printf_spec spec)
807 {
808 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
809 	unsigned long hashval;
810 	int ret;
811 
812 	/*
813 	 * Print the real pointer value for NULL and error pointers,
814 	 * as they are not actual addresses.
815 	 */
816 	if (IS_ERR_OR_NULL(ptr))
817 		return pointer_string(buf, end, ptr, spec);
818 
819 	/* When debugging early boot use non-cryptographically secure hash. */
820 	if (unlikely(debug_boot_weak_hash)) {
821 		hashval = hash_long((unsigned long)ptr, 32);
822 		return pointer_string(buf, end, (const void *)hashval, spec);
823 	}
824 
825 	ret = __ptr_to_hashval(ptr, &hashval);
826 	if (ret) {
827 		spec.field_width = 2 * sizeof(ptr);
828 		/* string length must be less than default_width */
829 		return error_string(buf, end, str, spec);
830 	}
831 
832 	return pointer_string(buf, end, (const void *)hashval, spec);
833 }
834 
835 static char *default_pointer(char *buf, char *end, const void *ptr,
836 			     struct printf_spec spec)
837 {
838 	/*
839 	 * default is to _not_ leak addresses, so hash before printing,
840 	 * unless no_hash_pointers is specified on the command line.
841 	 */
842 	if (unlikely(no_hash_pointers))
843 		return pointer_string(buf, end, ptr, spec);
844 
845 	return ptr_to_id(buf, end, ptr, spec);
846 }
847 
848 int kptr_restrict __read_mostly;
849 
850 static noinline_for_stack
851 char *restricted_pointer(char *buf, char *end, const void *ptr,
852 			 struct printf_spec spec)
853 {
854 	switch (kptr_restrict) {
855 	case 0:
856 		/* Handle as %p, hash and do _not_ leak addresses. */
857 		return default_pointer(buf, end, ptr, spec);
858 	case 1: {
859 		const struct cred *cred;
860 
861 		/*
862 		 * kptr_restrict==1 cannot be used in IRQ context
863 		 * because its test for CAP_SYSLOG would be meaningless.
864 		 */
865 		if (in_hardirq() || in_serving_softirq() || in_nmi()) {
866 			if (spec.field_width == -1)
867 				spec.field_width = 2 * sizeof(ptr);
868 			return error_string(buf, end, "pK-error", spec);
869 		}
870 
871 		/*
872 		 * Only print the real pointer value if the current
873 		 * process has CAP_SYSLOG and is running with the
874 		 * same credentials it started with. This is because
875 		 * access to files is checked at open() time, but %pK
876 		 * checks permission at read() time. We don't want to
877 		 * leak pointer values if a binary opens a file using
878 		 * %pK and then elevates privileges before reading it.
879 		 */
880 		cred = current_cred();
881 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
882 		    !uid_eq(cred->euid, cred->uid) ||
883 		    !gid_eq(cred->egid, cred->gid))
884 			ptr = NULL;
885 		break;
886 	}
887 	case 2:
888 	default:
889 		/* Always print 0's for %pK */
890 		ptr = NULL;
891 		break;
892 	}
893 
894 	return pointer_string(buf, end, ptr, spec);
895 }
896 
897 static noinline_for_stack
898 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
899 		  const char *fmt)
900 {
901 	const char *array[4], *s;
902 	const struct dentry *p;
903 	int depth;
904 	int i, n;
905 
906 	switch (fmt[1]) {
907 		case '2': case '3': case '4':
908 			depth = fmt[1] - '0';
909 			break;
910 		default:
911 			depth = 1;
912 	}
913 
914 	rcu_read_lock();
915 	for (i = 0; i < depth; i++, d = p) {
916 		if (check_pointer(&buf, end, d, spec)) {
917 			rcu_read_unlock();
918 			return buf;
919 		}
920 
921 		p = READ_ONCE(d->d_parent);
922 		array[i] = READ_ONCE(d->d_name.name);
923 		if (p == d) {
924 			if (i)
925 				array[i] = "";
926 			i++;
927 			break;
928 		}
929 	}
930 	s = array[--i];
931 	for (n = 0; n != spec.precision; n++, buf++) {
932 		char c = *s++;
933 		if (!c) {
934 			if (!i)
935 				break;
936 			c = '/';
937 			s = array[--i];
938 		}
939 		if (buf < end)
940 			*buf = c;
941 	}
942 	rcu_read_unlock();
943 	return widen_string(buf, n, end, spec);
944 }
945 
946 static noinline_for_stack
947 char *file_dentry_name(char *buf, char *end, const struct file *f,
948 			struct printf_spec spec, const char *fmt)
949 {
950 	if (check_pointer(&buf, end, f, spec))
951 		return buf;
952 
953 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
954 }
955 #ifdef CONFIG_BLOCK
956 static noinline_for_stack
957 char *bdev_name(char *buf, char *end, struct block_device *bdev,
958 		struct printf_spec spec, const char *fmt)
959 {
960 	struct gendisk *hd;
961 
962 	if (check_pointer(&buf, end, bdev, spec))
963 		return buf;
964 
965 	hd = bdev->bd_disk;
966 	buf = string(buf, end, hd->disk_name, spec);
967 	if (bdev->bd_partno) {
968 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
969 			if (buf < end)
970 				*buf = 'p';
971 			buf++;
972 		}
973 		buf = number(buf, end, bdev->bd_partno, spec);
974 	}
975 	return buf;
976 }
977 #endif
978 
979 static noinline_for_stack
980 char *symbol_string(char *buf, char *end, void *ptr,
981 		    struct printf_spec spec, const char *fmt)
982 {
983 	unsigned long value;
984 #ifdef CONFIG_KALLSYMS
985 	char sym[KSYM_SYMBOL_LEN];
986 #endif
987 
988 	if (fmt[1] == 'R')
989 		ptr = __builtin_extract_return_addr(ptr);
990 	value = (unsigned long)ptr;
991 
992 #ifdef CONFIG_KALLSYMS
993 	if (*fmt == 'B' && fmt[1] == 'b')
994 		sprint_backtrace_build_id(sym, value);
995 	else if (*fmt == 'B')
996 		sprint_backtrace(sym, value);
997 	else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
998 		sprint_symbol_build_id(sym, value);
999 	else if (*fmt != 's')
1000 		sprint_symbol(sym, value);
1001 	else
1002 		sprint_symbol_no_offset(sym, value);
1003 
1004 	return string_nocheck(buf, end, sym, spec);
1005 #else
1006 	return special_hex_number(buf, end, value, sizeof(void *));
1007 #endif
1008 }
1009 
1010 static const struct printf_spec default_str_spec = {
1011 	.field_width = -1,
1012 	.precision = -1,
1013 };
1014 
1015 static const struct printf_spec default_flag_spec = {
1016 	.base = 16,
1017 	.precision = -1,
1018 	.flags = SPECIAL | SMALL,
1019 };
1020 
1021 static const struct printf_spec default_dec_spec = {
1022 	.base = 10,
1023 	.precision = -1,
1024 };
1025 
1026 static const struct printf_spec default_dec02_spec = {
1027 	.base = 10,
1028 	.field_width = 2,
1029 	.precision = -1,
1030 	.flags = ZEROPAD,
1031 };
1032 
1033 static const struct printf_spec default_dec04_spec = {
1034 	.base = 10,
1035 	.field_width = 4,
1036 	.precision = -1,
1037 	.flags = ZEROPAD,
1038 };
1039 
1040 static noinline_for_stack
1041 char *resource_string(char *buf, char *end, struct resource *res,
1042 		      struct printf_spec spec, const char *fmt)
1043 {
1044 #ifndef IO_RSRC_PRINTK_SIZE
1045 #define IO_RSRC_PRINTK_SIZE	6
1046 #endif
1047 
1048 #ifndef MEM_RSRC_PRINTK_SIZE
1049 #define MEM_RSRC_PRINTK_SIZE	10
1050 #endif
1051 	static const struct printf_spec io_spec = {
1052 		.base = 16,
1053 		.field_width = IO_RSRC_PRINTK_SIZE,
1054 		.precision = -1,
1055 		.flags = SPECIAL | SMALL | ZEROPAD,
1056 	};
1057 	static const struct printf_spec mem_spec = {
1058 		.base = 16,
1059 		.field_width = MEM_RSRC_PRINTK_SIZE,
1060 		.precision = -1,
1061 		.flags = SPECIAL | SMALL | ZEROPAD,
1062 	};
1063 	static const struct printf_spec bus_spec = {
1064 		.base = 16,
1065 		.field_width = 2,
1066 		.precision = -1,
1067 		.flags = SMALL | ZEROPAD,
1068 	};
1069 	static const struct printf_spec str_spec = {
1070 		.field_width = -1,
1071 		.precision = 10,
1072 		.flags = LEFT,
1073 	};
1074 
1075 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1076 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1077 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1078 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1079 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1080 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1081 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1082 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1083 
1084 	char *p = sym, *pend = sym + sizeof(sym);
1085 	int decode = (fmt[0] == 'R') ? 1 : 0;
1086 	const struct printf_spec *specp;
1087 
1088 	if (check_pointer(&buf, end, res, spec))
1089 		return buf;
1090 
1091 	*p++ = '[';
1092 	if (res->flags & IORESOURCE_IO) {
1093 		p = string_nocheck(p, pend, "io  ", str_spec);
1094 		specp = &io_spec;
1095 	} else if (res->flags & IORESOURCE_MEM) {
1096 		p = string_nocheck(p, pend, "mem ", str_spec);
1097 		specp = &mem_spec;
1098 	} else if (res->flags & IORESOURCE_IRQ) {
1099 		p = string_nocheck(p, pend, "irq ", str_spec);
1100 		specp = &default_dec_spec;
1101 	} else if (res->flags & IORESOURCE_DMA) {
1102 		p = string_nocheck(p, pend, "dma ", str_spec);
1103 		specp = &default_dec_spec;
1104 	} else if (res->flags & IORESOURCE_BUS) {
1105 		p = string_nocheck(p, pend, "bus ", str_spec);
1106 		specp = &bus_spec;
1107 	} else {
1108 		p = string_nocheck(p, pend, "??? ", str_spec);
1109 		specp = &mem_spec;
1110 		decode = 0;
1111 	}
1112 	if (decode && res->flags & IORESOURCE_UNSET) {
1113 		p = string_nocheck(p, pend, "size ", str_spec);
1114 		p = number(p, pend, resource_size(res), *specp);
1115 	} else {
1116 		p = number(p, pend, res->start, *specp);
1117 		if (res->start != res->end) {
1118 			*p++ = '-';
1119 			p = number(p, pend, res->end, *specp);
1120 		}
1121 	}
1122 	if (decode) {
1123 		if (res->flags & IORESOURCE_MEM_64)
1124 			p = string_nocheck(p, pend, " 64bit", str_spec);
1125 		if (res->flags & IORESOURCE_PREFETCH)
1126 			p = string_nocheck(p, pend, " pref", str_spec);
1127 		if (res->flags & IORESOURCE_WINDOW)
1128 			p = string_nocheck(p, pend, " window", str_spec);
1129 		if (res->flags & IORESOURCE_DISABLED)
1130 			p = string_nocheck(p, pend, " disabled", str_spec);
1131 	} else {
1132 		p = string_nocheck(p, pend, " flags ", str_spec);
1133 		p = number(p, pend, res->flags, default_flag_spec);
1134 	}
1135 	*p++ = ']';
1136 	*p = '\0';
1137 
1138 	return string_nocheck(buf, end, sym, spec);
1139 }
1140 
1141 static noinline_for_stack
1142 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1143 		 const char *fmt)
1144 {
1145 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1146 				   negative value, fallback to the default */
1147 	char separator;
1148 
1149 	if (spec.field_width == 0)
1150 		/* nothing to print */
1151 		return buf;
1152 
1153 	if (check_pointer(&buf, end, addr, spec))
1154 		return buf;
1155 
1156 	switch (fmt[1]) {
1157 	case 'C':
1158 		separator = ':';
1159 		break;
1160 	case 'D':
1161 		separator = '-';
1162 		break;
1163 	case 'N':
1164 		separator = 0;
1165 		break;
1166 	default:
1167 		separator = ' ';
1168 		break;
1169 	}
1170 
1171 	if (spec.field_width > 0)
1172 		len = min_t(int, spec.field_width, 64);
1173 
1174 	for (i = 0; i < len; ++i) {
1175 		if (buf < end)
1176 			*buf = hex_asc_hi(addr[i]);
1177 		++buf;
1178 		if (buf < end)
1179 			*buf = hex_asc_lo(addr[i]);
1180 		++buf;
1181 
1182 		if (separator && i != len - 1) {
1183 			if (buf < end)
1184 				*buf = separator;
1185 			++buf;
1186 		}
1187 	}
1188 
1189 	return buf;
1190 }
1191 
1192 static noinline_for_stack
1193 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1194 		    struct printf_spec spec, const char *fmt)
1195 {
1196 	const int CHUNKSZ = 32;
1197 	int nr_bits = max_t(int, spec.field_width, 0);
1198 	int i, chunksz;
1199 	bool first = true;
1200 
1201 	if (check_pointer(&buf, end, bitmap, spec))
1202 		return buf;
1203 
1204 	/* reused to print numbers */
1205 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1206 
1207 	chunksz = nr_bits & (CHUNKSZ - 1);
1208 	if (chunksz == 0)
1209 		chunksz = CHUNKSZ;
1210 
1211 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1212 	for (; i >= 0; i -= CHUNKSZ) {
1213 		u32 chunkmask, val;
1214 		int word, bit;
1215 
1216 		chunkmask = ((1ULL << chunksz) - 1);
1217 		word = i / BITS_PER_LONG;
1218 		bit = i % BITS_PER_LONG;
1219 		val = (bitmap[word] >> bit) & chunkmask;
1220 
1221 		if (!first) {
1222 			if (buf < end)
1223 				*buf = ',';
1224 			buf++;
1225 		}
1226 		first = false;
1227 
1228 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1229 		buf = number(buf, end, val, spec);
1230 
1231 		chunksz = CHUNKSZ;
1232 	}
1233 	return buf;
1234 }
1235 
1236 static noinline_for_stack
1237 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1238 			 struct printf_spec spec, const char *fmt)
1239 {
1240 	int nr_bits = max_t(int, spec.field_width, 0);
1241 	bool first = true;
1242 	int rbot, rtop;
1243 
1244 	if (check_pointer(&buf, end, bitmap, spec))
1245 		return buf;
1246 
1247 	for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1248 		if (!first) {
1249 			if (buf < end)
1250 				*buf = ',';
1251 			buf++;
1252 		}
1253 		first = false;
1254 
1255 		buf = number(buf, end, rbot, default_dec_spec);
1256 		if (rtop == rbot + 1)
1257 			continue;
1258 
1259 		if (buf < end)
1260 			*buf = '-';
1261 		buf = number(++buf, end, rtop - 1, default_dec_spec);
1262 	}
1263 	return buf;
1264 }
1265 
1266 static noinline_for_stack
1267 char *mac_address_string(char *buf, char *end, u8 *addr,
1268 			 struct printf_spec spec, const char *fmt)
1269 {
1270 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1271 	char *p = mac_addr;
1272 	int i;
1273 	char separator;
1274 	bool reversed = false;
1275 
1276 	if (check_pointer(&buf, end, addr, spec))
1277 		return buf;
1278 
1279 	switch (fmt[1]) {
1280 	case 'F':
1281 		separator = '-';
1282 		break;
1283 
1284 	case 'R':
1285 		reversed = true;
1286 		fallthrough;
1287 
1288 	default:
1289 		separator = ':';
1290 		break;
1291 	}
1292 
1293 	for (i = 0; i < 6; i++) {
1294 		if (reversed)
1295 			p = hex_byte_pack(p, addr[5 - i]);
1296 		else
1297 			p = hex_byte_pack(p, addr[i]);
1298 
1299 		if (fmt[0] == 'M' && i != 5)
1300 			*p++ = separator;
1301 	}
1302 	*p = '\0';
1303 
1304 	return string_nocheck(buf, end, mac_addr, spec);
1305 }
1306 
1307 static noinline_for_stack
1308 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1309 {
1310 	int i;
1311 	bool leading_zeros = (fmt[0] == 'i');
1312 	int index;
1313 	int step;
1314 
1315 	switch (fmt[2]) {
1316 	case 'h':
1317 #ifdef __BIG_ENDIAN
1318 		index = 0;
1319 		step = 1;
1320 #else
1321 		index = 3;
1322 		step = -1;
1323 #endif
1324 		break;
1325 	case 'l':
1326 		index = 3;
1327 		step = -1;
1328 		break;
1329 	case 'n':
1330 	case 'b':
1331 	default:
1332 		index = 0;
1333 		step = 1;
1334 		break;
1335 	}
1336 	for (i = 0; i < 4; i++) {
1337 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1338 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1339 		if (leading_zeros) {
1340 			if (digits < 3)
1341 				*p++ = '0';
1342 			if (digits < 2)
1343 				*p++ = '0';
1344 		}
1345 		/* reverse the digits in the quad */
1346 		while (digits--)
1347 			*p++ = temp[digits];
1348 		if (i < 3)
1349 			*p++ = '.';
1350 		index += step;
1351 	}
1352 	*p = '\0';
1353 
1354 	return p;
1355 }
1356 
1357 static noinline_for_stack
1358 char *ip6_compressed_string(char *p, const char *addr)
1359 {
1360 	int i, j, range;
1361 	unsigned char zerolength[8];
1362 	int longest = 1;
1363 	int colonpos = -1;
1364 	u16 word;
1365 	u8 hi, lo;
1366 	bool needcolon = false;
1367 	bool useIPv4;
1368 	struct in6_addr in6;
1369 
1370 	memcpy(&in6, addr, sizeof(struct in6_addr));
1371 
1372 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1373 
1374 	memset(zerolength, 0, sizeof(zerolength));
1375 
1376 	if (useIPv4)
1377 		range = 6;
1378 	else
1379 		range = 8;
1380 
1381 	/* find position of longest 0 run */
1382 	for (i = 0; i < range; i++) {
1383 		for (j = i; j < range; j++) {
1384 			if (in6.s6_addr16[j] != 0)
1385 				break;
1386 			zerolength[i]++;
1387 		}
1388 	}
1389 	for (i = 0; i < range; i++) {
1390 		if (zerolength[i] > longest) {
1391 			longest = zerolength[i];
1392 			colonpos = i;
1393 		}
1394 	}
1395 	if (longest == 1)		/* don't compress a single 0 */
1396 		colonpos = -1;
1397 
1398 	/* emit address */
1399 	for (i = 0; i < range; i++) {
1400 		if (i == colonpos) {
1401 			if (needcolon || i == 0)
1402 				*p++ = ':';
1403 			*p++ = ':';
1404 			needcolon = false;
1405 			i += longest - 1;
1406 			continue;
1407 		}
1408 		if (needcolon) {
1409 			*p++ = ':';
1410 			needcolon = false;
1411 		}
1412 		/* hex u16 without leading 0s */
1413 		word = ntohs(in6.s6_addr16[i]);
1414 		hi = word >> 8;
1415 		lo = word & 0xff;
1416 		if (hi) {
1417 			if (hi > 0x0f)
1418 				p = hex_byte_pack(p, hi);
1419 			else
1420 				*p++ = hex_asc_lo(hi);
1421 			p = hex_byte_pack(p, lo);
1422 		}
1423 		else if (lo > 0x0f)
1424 			p = hex_byte_pack(p, lo);
1425 		else
1426 			*p++ = hex_asc_lo(lo);
1427 		needcolon = true;
1428 	}
1429 
1430 	if (useIPv4) {
1431 		if (needcolon)
1432 			*p++ = ':';
1433 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1434 	}
1435 	*p = '\0';
1436 
1437 	return p;
1438 }
1439 
1440 static noinline_for_stack
1441 char *ip6_string(char *p, const char *addr, const char *fmt)
1442 {
1443 	int i;
1444 
1445 	for (i = 0; i < 8; i++) {
1446 		p = hex_byte_pack(p, *addr++);
1447 		p = hex_byte_pack(p, *addr++);
1448 		if (fmt[0] == 'I' && i != 7)
1449 			*p++ = ':';
1450 	}
1451 	*p = '\0';
1452 
1453 	return p;
1454 }
1455 
1456 static noinline_for_stack
1457 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1458 		      struct printf_spec spec, const char *fmt)
1459 {
1460 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1461 
1462 	if (fmt[0] == 'I' && fmt[2] == 'c')
1463 		ip6_compressed_string(ip6_addr, addr);
1464 	else
1465 		ip6_string(ip6_addr, addr, fmt);
1466 
1467 	return string_nocheck(buf, end, ip6_addr, spec);
1468 }
1469 
1470 static noinline_for_stack
1471 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1472 		      struct printf_spec spec, const char *fmt)
1473 {
1474 	char ip4_addr[sizeof("255.255.255.255")];
1475 
1476 	ip4_string(ip4_addr, addr, fmt);
1477 
1478 	return string_nocheck(buf, end, ip4_addr, spec);
1479 }
1480 
1481 static noinline_for_stack
1482 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1483 			 struct printf_spec spec, const char *fmt)
1484 {
1485 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1486 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1487 		      sizeof(":12345") + sizeof("/123456789") +
1488 		      sizeof("%1234567890")];
1489 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1490 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1491 	char fmt6[2] = { fmt[0], '6' };
1492 	u8 off = 0;
1493 
1494 	fmt++;
1495 	while (isalpha(*++fmt)) {
1496 		switch (*fmt) {
1497 		case 'p':
1498 			have_p = true;
1499 			break;
1500 		case 'f':
1501 			have_f = true;
1502 			break;
1503 		case 's':
1504 			have_s = true;
1505 			break;
1506 		case 'c':
1507 			have_c = true;
1508 			break;
1509 		}
1510 	}
1511 
1512 	if (have_p || have_s || have_f) {
1513 		*p = '[';
1514 		off = 1;
1515 	}
1516 
1517 	if (fmt6[0] == 'I' && have_c)
1518 		p = ip6_compressed_string(ip6_addr + off, addr);
1519 	else
1520 		p = ip6_string(ip6_addr + off, addr, fmt6);
1521 
1522 	if (have_p || have_s || have_f)
1523 		*p++ = ']';
1524 
1525 	if (have_p) {
1526 		*p++ = ':';
1527 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1528 	}
1529 	if (have_f) {
1530 		*p++ = '/';
1531 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1532 					  IPV6_FLOWINFO_MASK), spec);
1533 	}
1534 	if (have_s) {
1535 		*p++ = '%';
1536 		p = number(p, pend, sa->sin6_scope_id, spec);
1537 	}
1538 	*p = '\0';
1539 
1540 	return string_nocheck(buf, end, ip6_addr, spec);
1541 }
1542 
1543 static noinline_for_stack
1544 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1545 			 struct printf_spec spec, const char *fmt)
1546 {
1547 	bool have_p = false;
1548 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1549 	char *pend = ip4_addr + sizeof(ip4_addr);
1550 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1551 	char fmt4[3] = { fmt[0], '4', 0 };
1552 
1553 	fmt++;
1554 	while (isalpha(*++fmt)) {
1555 		switch (*fmt) {
1556 		case 'p':
1557 			have_p = true;
1558 			break;
1559 		case 'h':
1560 		case 'l':
1561 		case 'n':
1562 		case 'b':
1563 			fmt4[2] = *fmt;
1564 			break;
1565 		}
1566 	}
1567 
1568 	p = ip4_string(ip4_addr, addr, fmt4);
1569 	if (have_p) {
1570 		*p++ = ':';
1571 		p = number(p, pend, ntohs(sa->sin_port), spec);
1572 	}
1573 	*p = '\0';
1574 
1575 	return string_nocheck(buf, end, ip4_addr, spec);
1576 }
1577 
1578 static noinline_for_stack
1579 char *ip_addr_string(char *buf, char *end, const void *ptr,
1580 		     struct printf_spec spec, const char *fmt)
1581 {
1582 	char *err_fmt_msg;
1583 
1584 	if (check_pointer(&buf, end, ptr, spec))
1585 		return buf;
1586 
1587 	switch (fmt[1]) {
1588 	case '6':
1589 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1590 	case '4':
1591 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1592 	case 'S': {
1593 		const union {
1594 			struct sockaddr		raw;
1595 			struct sockaddr_in	v4;
1596 			struct sockaddr_in6	v6;
1597 		} *sa = ptr;
1598 
1599 		switch (sa->raw.sa_family) {
1600 		case AF_INET:
1601 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1602 		case AF_INET6:
1603 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1604 		default:
1605 			return error_string(buf, end, "(einval)", spec);
1606 		}}
1607 	}
1608 
1609 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1610 	return error_string(buf, end, err_fmt_msg, spec);
1611 }
1612 
1613 static noinline_for_stack
1614 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1615 		     const char *fmt)
1616 {
1617 	bool found = true;
1618 	int count = 1;
1619 	unsigned int flags = 0;
1620 	int len;
1621 
1622 	if (spec.field_width == 0)
1623 		return buf;				/* nothing to print */
1624 
1625 	if (check_pointer(&buf, end, addr, spec))
1626 		return buf;
1627 
1628 	do {
1629 		switch (fmt[count++]) {
1630 		case 'a':
1631 			flags |= ESCAPE_ANY;
1632 			break;
1633 		case 'c':
1634 			flags |= ESCAPE_SPECIAL;
1635 			break;
1636 		case 'h':
1637 			flags |= ESCAPE_HEX;
1638 			break;
1639 		case 'n':
1640 			flags |= ESCAPE_NULL;
1641 			break;
1642 		case 'o':
1643 			flags |= ESCAPE_OCTAL;
1644 			break;
1645 		case 'p':
1646 			flags |= ESCAPE_NP;
1647 			break;
1648 		case 's':
1649 			flags |= ESCAPE_SPACE;
1650 			break;
1651 		default:
1652 			found = false;
1653 			break;
1654 		}
1655 	} while (found);
1656 
1657 	if (!flags)
1658 		flags = ESCAPE_ANY_NP;
1659 
1660 	len = spec.field_width < 0 ? 1 : spec.field_width;
1661 
1662 	/*
1663 	 * string_escape_mem() writes as many characters as it can to
1664 	 * the given buffer, and returns the total size of the output
1665 	 * had the buffer been big enough.
1666 	 */
1667 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1668 
1669 	return buf;
1670 }
1671 
1672 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1673 		       struct printf_spec spec, const char *fmt)
1674 {
1675 	va_list va;
1676 
1677 	if (check_pointer(&buf, end, va_fmt, spec))
1678 		return buf;
1679 
1680 	va_copy(va, *va_fmt->va);
1681 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1682 	va_end(va);
1683 
1684 	return buf;
1685 }
1686 
1687 static noinline_for_stack
1688 char *uuid_string(char *buf, char *end, const u8 *addr,
1689 		  struct printf_spec spec, const char *fmt)
1690 {
1691 	char uuid[UUID_STRING_LEN + 1];
1692 	char *p = uuid;
1693 	int i;
1694 	const u8 *index = uuid_index;
1695 	bool uc = false;
1696 
1697 	if (check_pointer(&buf, end, addr, spec))
1698 		return buf;
1699 
1700 	switch (*(++fmt)) {
1701 	case 'L':
1702 		uc = true;
1703 		fallthrough;
1704 	case 'l':
1705 		index = guid_index;
1706 		break;
1707 	case 'B':
1708 		uc = true;
1709 		break;
1710 	}
1711 
1712 	for (i = 0; i < 16; i++) {
1713 		if (uc)
1714 			p = hex_byte_pack_upper(p, addr[index[i]]);
1715 		else
1716 			p = hex_byte_pack(p, addr[index[i]]);
1717 		switch (i) {
1718 		case 3:
1719 		case 5:
1720 		case 7:
1721 		case 9:
1722 			*p++ = '-';
1723 			break;
1724 		}
1725 	}
1726 
1727 	*p = 0;
1728 
1729 	return string_nocheck(buf, end, uuid, spec);
1730 }
1731 
1732 static noinline_for_stack
1733 char *netdev_bits(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 'F':
1744 		num = *(const netdev_features_t *)addr;
1745 		size = sizeof(netdev_features_t);
1746 		break;
1747 	default:
1748 		return error_string(buf, end, "(%pN?)", spec);
1749 	}
1750 
1751 	return special_hex_number(buf, end, num, size);
1752 }
1753 
1754 static noinline_for_stack
1755 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1756 		    struct printf_spec spec, const char *fmt)
1757 {
1758 	char output[sizeof("0123 little-endian (0x01234567)")];
1759 	char *p = output;
1760 	unsigned int i;
1761 	u32 orig, val;
1762 
1763 	if (fmt[1] != 'c' || fmt[2] != 'c')
1764 		return error_string(buf, end, "(%p4?)", spec);
1765 
1766 	if (check_pointer(&buf, end, fourcc, spec))
1767 		return buf;
1768 
1769 	orig = get_unaligned(fourcc);
1770 	val = orig & ~BIT(31);
1771 
1772 	for (i = 0; i < sizeof(u32); i++) {
1773 		unsigned char c = val >> (i * 8);
1774 
1775 		/* Print non-control ASCII characters as-is, dot otherwise */
1776 		*p++ = isascii(c) && isprint(c) ? c : '.';
1777 	}
1778 
1779 	*p++ = ' ';
1780 	strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1781 	p += strlen(p);
1782 
1783 	*p++ = ' ';
1784 	*p++ = '(';
1785 	p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1786 	*p++ = ')';
1787 	*p = '\0';
1788 
1789 	return string(buf, end, output, spec);
1790 }
1791 
1792 static noinline_for_stack
1793 char *address_val(char *buf, char *end, const void *addr,
1794 		  struct printf_spec spec, const char *fmt)
1795 {
1796 	unsigned long long num;
1797 	int size;
1798 
1799 	if (check_pointer(&buf, end, addr, spec))
1800 		return buf;
1801 
1802 	switch (fmt[1]) {
1803 	case 'd':
1804 		num = *(const dma_addr_t *)addr;
1805 		size = sizeof(dma_addr_t);
1806 		break;
1807 	case 'p':
1808 	default:
1809 		num = *(const phys_addr_t *)addr;
1810 		size = sizeof(phys_addr_t);
1811 		break;
1812 	}
1813 
1814 	return special_hex_number(buf, end, num, size);
1815 }
1816 
1817 static noinline_for_stack
1818 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1819 {
1820 	int year = tm->tm_year + (r ? 0 : 1900);
1821 	int mon = tm->tm_mon + (r ? 0 : 1);
1822 
1823 	buf = number(buf, end, year, default_dec04_spec);
1824 	if (buf < end)
1825 		*buf = '-';
1826 	buf++;
1827 
1828 	buf = number(buf, end, mon, default_dec02_spec);
1829 	if (buf < end)
1830 		*buf = '-';
1831 	buf++;
1832 
1833 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1834 }
1835 
1836 static noinline_for_stack
1837 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1838 {
1839 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1840 	if (buf < end)
1841 		*buf = ':';
1842 	buf++;
1843 
1844 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1845 	if (buf < end)
1846 		*buf = ':';
1847 	buf++;
1848 
1849 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1850 }
1851 
1852 static noinline_for_stack
1853 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1854 	      struct printf_spec spec, const char *fmt)
1855 {
1856 	bool have_t = true, have_d = true;
1857 	bool raw = false, iso8601_separator = true;
1858 	bool found = true;
1859 	int count = 2;
1860 
1861 	if (check_pointer(&buf, end, tm, spec))
1862 		return buf;
1863 
1864 	switch (fmt[count]) {
1865 	case 'd':
1866 		have_t = false;
1867 		count++;
1868 		break;
1869 	case 't':
1870 		have_d = false;
1871 		count++;
1872 		break;
1873 	}
1874 
1875 	do {
1876 		switch (fmt[count++]) {
1877 		case 'r':
1878 			raw = true;
1879 			break;
1880 		case 's':
1881 			iso8601_separator = false;
1882 			break;
1883 		default:
1884 			found = false;
1885 			break;
1886 		}
1887 	} while (found);
1888 
1889 	if (have_d)
1890 		buf = date_str(buf, end, tm, raw);
1891 	if (have_d && have_t) {
1892 		if (buf < end)
1893 			*buf = iso8601_separator ? 'T' : ' ';
1894 		buf++;
1895 	}
1896 	if (have_t)
1897 		buf = time_str(buf, end, tm, raw);
1898 
1899 	return buf;
1900 }
1901 
1902 static noinline_for_stack
1903 char *time64_str(char *buf, char *end, const time64_t time,
1904 		 struct printf_spec spec, const char *fmt)
1905 {
1906 	struct rtc_time rtc_time;
1907 	struct tm tm;
1908 
1909 	time64_to_tm(time, 0, &tm);
1910 
1911 	rtc_time.tm_sec = tm.tm_sec;
1912 	rtc_time.tm_min = tm.tm_min;
1913 	rtc_time.tm_hour = tm.tm_hour;
1914 	rtc_time.tm_mday = tm.tm_mday;
1915 	rtc_time.tm_mon = tm.tm_mon;
1916 	rtc_time.tm_year = tm.tm_year;
1917 	rtc_time.tm_wday = tm.tm_wday;
1918 	rtc_time.tm_yday = tm.tm_yday;
1919 
1920 	rtc_time.tm_isdst = 0;
1921 
1922 	return rtc_str(buf, end, &rtc_time, spec, fmt);
1923 }
1924 
1925 static noinline_for_stack
1926 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1927 		    const char *fmt)
1928 {
1929 	switch (fmt[1]) {
1930 	case 'R':
1931 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1932 	case 'T':
1933 		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1934 	default:
1935 		return error_string(buf, end, "(%pt?)", spec);
1936 	}
1937 }
1938 
1939 static noinline_for_stack
1940 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1941 	    const char *fmt)
1942 {
1943 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1944 		return error_string(buf, end, "(%pC?)", spec);
1945 
1946 	if (check_pointer(&buf, end, clk, spec))
1947 		return buf;
1948 
1949 	switch (fmt[1]) {
1950 	case 'n':
1951 	default:
1952 #ifdef CONFIG_COMMON_CLK
1953 		return string(buf, end, __clk_get_name(clk), spec);
1954 #else
1955 		return ptr_to_id(buf, end, clk, spec);
1956 #endif
1957 	}
1958 }
1959 
1960 static
1961 char *format_flags(char *buf, char *end, unsigned long flags,
1962 					const struct trace_print_flags *names)
1963 {
1964 	unsigned long mask;
1965 
1966 	for ( ; flags && names->name; names++) {
1967 		mask = names->mask;
1968 		if ((flags & mask) != mask)
1969 			continue;
1970 
1971 		buf = string(buf, end, names->name, default_str_spec);
1972 
1973 		flags &= ~mask;
1974 		if (flags) {
1975 			if (buf < end)
1976 				*buf = '|';
1977 			buf++;
1978 		}
1979 	}
1980 
1981 	if (flags)
1982 		buf = number(buf, end, flags, default_flag_spec);
1983 
1984 	return buf;
1985 }
1986 
1987 struct page_flags_fields {
1988 	int width;
1989 	int shift;
1990 	int mask;
1991 	const struct printf_spec *spec;
1992 	const char *name;
1993 };
1994 
1995 static const struct page_flags_fields pff[] = {
1996 	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
1997 	 &default_dec_spec, "section"},
1998 	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
1999 	 &default_dec_spec, "node"},
2000 	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2001 	 &default_dec_spec, "zone"},
2002 	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2003 	 &default_flag_spec, "lastcpupid"},
2004 	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2005 	 &default_flag_spec, "kasantag"},
2006 };
2007 
2008 static
2009 char *format_page_flags(char *buf, char *end, unsigned long flags)
2010 {
2011 	unsigned long main_flags = flags & PAGEFLAGS_MASK;
2012 	bool append = false;
2013 	int i;
2014 
2015 	buf = number(buf, end, flags, default_flag_spec);
2016 	if (buf < end)
2017 		*buf = '(';
2018 	buf++;
2019 
2020 	/* Page flags from the main area. */
2021 	if (main_flags) {
2022 		buf = format_flags(buf, end, main_flags, pageflag_names);
2023 		append = true;
2024 	}
2025 
2026 	/* Page flags from the fields area */
2027 	for (i = 0; i < ARRAY_SIZE(pff); i++) {
2028 		/* Skip undefined fields. */
2029 		if (!pff[i].width)
2030 			continue;
2031 
2032 		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2033 		if (append) {
2034 			if (buf < end)
2035 				*buf = '|';
2036 			buf++;
2037 		}
2038 
2039 		buf = string(buf, end, pff[i].name, default_str_spec);
2040 		if (buf < end)
2041 			*buf = '=';
2042 		buf++;
2043 		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2044 			     *pff[i].spec);
2045 
2046 		append = true;
2047 	}
2048 	if (buf < end)
2049 		*buf = ')';
2050 	buf++;
2051 
2052 	return buf;
2053 }
2054 
2055 static
2056 char *format_page_type(char *buf, char *end, unsigned int page_type)
2057 {
2058 	buf = number(buf, end, page_type, default_flag_spec);
2059 
2060 	if (buf < end)
2061 		*buf = '(';
2062 	buf++;
2063 
2064 	if (page_type_has_type(page_type))
2065 		buf = format_flags(buf, end, ~page_type, pagetype_names);
2066 
2067 	if (buf < end)
2068 		*buf = ')';
2069 	buf++;
2070 
2071 	return buf;
2072 }
2073 
2074 static noinline_for_stack
2075 char *flags_string(char *buf, char *end, void *flags_ptr,
2076 		   struct printf_spec spec, const char *fmt)
2077 {
2078 	unsigned long flags;
2079 	const struct trace_print_flags *names;
2080 
2081 	if (check_pointer(&buf, end, flags_ptr, spec))
2082 		return buf;
2083 
2084 	switch (fmt[1]) {
2085 	case 'p':
2086 		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2087 	case 't':
2088 		return format_page_type(buf, end, *(unsigned int *)flags_ptr);
2089 	case 'v':
2090 		flags = *(unsigned long *)flags_ptr;
2091 		names = vmaflag_names;
2092 		break;
2093 	case 'g':
2094 		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2095 		names = gfpflag_names;
2096 		break;
2097 	default:
2098 		return error_string(buf, end, "(%pG?)", spec);
2099 	}
2100 
2101 	return format_flags(buf, end, flags, names);
2102 }
2103 
2104 static noinline_for_stack
2105 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2106 			      char *end)
2107 {
2108 	int depth;
2109 
2110 	/* Loop starting from the root node to the current node. */
2111 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2112 		struct fwnode_handle *__fwnode =
2113 			fwnode_get_nth_parent(fwnode, depth);
2114 
2115 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2116 			     default_str_spec);
2117 		buf = string(buf, end, fwnode_get_name(__fwnode),
2118 			     default_str_spec);
2119 
2120 		fwnode_handle_put(__fwnode);
2121 	}
2122 
2123 	return buf;
2124 }
2125 
2126 static noinline_for_stack
2127 char *device_node_string(char *buf, char *end, struct device_node *dn,
2128 			 struct printf_spec spec, const char *fmt)
2129 {
2130 	char tbuf[sizeof("xxxx") + 1];
2131 	const char *p;
2132 	int ret;
2133 	char *buf_start = buf;
2134 	struct property *prop;
2135 	bool has_mult, pass;
2136 
2137 	struct printf_spec str_spec = spec;
2138 	str_spec.field_width = -1;
2139 
2140 	if (fmt[0] != 'F')
2141 		return error_string(buf, end, "(%pO?)", spec);
2142 
2143 	if (!IS_ENABLED(CONFIG_OF))
2144 		return error_string(buf, end, "(%pOF?)", spec);
2145 
2146 	if (check_pointer(&buf, end, dn, spec))
2147 		return buf;
2148 
2149 	/* simple case without anything any more format specifiers */
2150 	fmt++;
2151 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2152 		fmt = "f";
2153 
2154 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2155 		int precision;
2156 		if (pass) {
2157 			if (buf < end)
2158 				*buf = ':';
2159 			buf++;
2160 		}
2161 
2162 		switch (*fmt) {
2163 		case 'f':	/* full_name */
2164 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2165 						      end);
2166 			break;
2167 		case 'n':	/* name */
2168 			p = fwnode_get_name(of_fwnode_handle(dn));
2169 			precision = str_spec.precision;
2170 			str_spec.precision = strchrnul(p, '@') - p;
2171 			buf = string(buf, end, p, str_spec);
2172 			str_spec.precision = precision;
2173 			break;
2174 		case 'p':	/* phandle */
2175 			buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2176 			break;
2177 		case 'P':	/* path-spec */
2178 			p = fwnode_get_name(of_fwnode_handle(dn));
2179 			if (!p[1])
2180 				p = "/";
2181 			buf = string(buf, end, p, str_spec);
2182 			break;
2183 		case 'F':	/* flags */
2184 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2185 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2186 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2187 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2188 			tbuf[4] = 0;
2189 			buf = string_nocheck(buf, end, tbuf, str_spec);
2190 			break;
2191 		case 'c':	/* major compatible string */
2192 			ret = of_property_read_string(dn, "compatible", &p);
2193 			if (!ret)
2194 				buf = string(buf, end, p, str_spec);
2195 			break;
2196 		case 'C':	/* full compatible string */
2197 			has_mult = false;
2198 			of_property_for_each_string(dn, "compatible", prop, p) {
2199 				if (has_mult)
2200 					buf = string_nocheck(buf, end, ",", str_spec);
2201 				buf = string_nocheck(buf, end, "\"", str_spec);
2202 				buf = string(buf, end, p, str_spec);
2203 				buf = string_nocheck(buf, end, "\"", str_spec);
2204 
2205 				has_mult = true;
2206 			}
2207 			break;
2208 		default:
2209 			break;
2210 		}
2211 	}
2212 
2213 	return widen_string(buf, buf - buf_start, end, spec);
2214 }
2215 
2216 static noinline_for_stack
2217 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2218 		    struct printf_spec spec, const char *fmt)
2219 {
2220 	struct printf_spec str_spec = spec;
2221 	char *buf_start = buf;
2222 
2223 	str_spec.field_width = -1;
2224 
2225 	if (*fmt != 'w')
2226 		return error_string(buf, end, "(%pf?)", spec);
2227 
2228 	if (check_pointer(&buf, end, fwnode, spec))
2229 		return buf;
2230 
2231 	fmt++;
2232 
2233 	switch (*fmt) {
2234 	case 'P':	/* name */
2235 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2236 		break;
2237 	case 'f':	/* full_name */
2238 	default:
2239 		buf = fwnode_full_name_string(fwnode, buf, end);
2240 		break;
2241 	}
2242 
2243 	return widen_string(buf, buf - buf_start, end, spec);
2244 }
2245 
2246 int __init no_hash_pointers_enable(char *str)
2247 {
2248 	if (no_hash_pointers)
2249 		return 0;
2250 
2251 	no_hash_pointers = true;
2252 
2253 	pr_warn("**********************************************************\n");
2254 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2255 	pr_warn("**                                                      **\n");
2256 	pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2257 	pr_warn("** via the console, logs, and other interfaces. This    **\n");
2258 	pr_warn("** might reduce the security of your system.            **\n");
2259 	pr_warn("**                                                      **\n");
2260 	pr_warn("** If you see this message and you are not debugging    **\n");
2261 	pr_warn("** the kernel, report this immediately to your system   **\n");
2262 	pr_warn("** administrator!                                       **\n");
2263 	pr_warn("**                                                      **\n");
2264 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2265 	pr_warn("**********************************************************\n");
2266 
2267 	return 0;
2268 }
2269 early_param("no_hash_pointers", no_hash_pointers_enable);
2270 
2271 /* Used for Rust formatting ('%pA'). */
2272 char *rust_fmt_argument(char *buf, char *end, void *ptr);
2273 
2274 /*
2275  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2276  * by an extra set of alphanumeric characters that are extended format
2277  * specifiers.
2278  *
2279  * Please update scripts/checkpatch.pl when adding/removing conversion
2280  * characters.  (Search for "check for vsprintf extension").
2281  *
2282  * Right now we handle:
2283  *
2284  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2285  * - 's' For symbolic direct pointers (or function descriptors) without offset
2286  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2287  * - 'S[R]b' as above with module build ID (for use in backtraces)
2288  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2289  *	    %ps and %pS. Be careful when re-using these specifiers.
2290  * - 'B' For backtraced symbolic direct pointers with offset
2291  * - 'Bb' as above with module build ID (for use in backtraces)
2292  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2293  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2294  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2295  *       width which must be explicitly specified either as part of the
2296  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2297  *       range-list format instead of hex format
2298  * - 'M' For a 6-byte MAC address, it prints the address in the
2299  *       usual colon-separated hex notation
2300  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2301  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2302  *       with a dash-separated hex notation
2303  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2304  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2305  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2306  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2307  *       [S][pfs]
2308  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2309  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2310  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2311  *       IPv6 omits the colons (01020304...0f)
2312  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2313  *       [S][pfs]
2314  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2315  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2316  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2317  * - 'I[6S]c' for IPv6 addresses printed as specified by
2318  *       https://tools.ietf.org/html/rfc5952
2319  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2320  *                of the following flags (see string_escape_mem() for the
2321  *                details):
2322  *                  a - ESCAPE_ANY
2323  *                  c - ESCAPE_SPECIAL
2324  *                  h - ESCAPE_HEX
2325  *                  n - ESCAPE_NULL
2326  *                  o - ESCAPE_OCTAL
2327  *                  p - ESCAPE_NP
2328  *                  s - ESCAPE_SPACE
2329  *                By default ESCAPE_ANY_NP is used.
2330  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2331  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2332  *       Options for %pU are:
2333  *         b big endian lower case hex (default)
2334  *         B big endian UPPER case hex
2335  *         l little endian lower case hex
2336  *         L little endian UPPER case hex
2337  *           big endian output byte order is:
2338  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2339  *           little endian output byte order is:
2340  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2341  * - 'V' For a struct va_format which contains a format string * and va_list *,
2342  *       call vsnprintf(->format, *->va_list).
2343  *       Implements a "recursive vsnprintf".
2344  *       Do not use this feature without some mechanism to verify the
2345  *       correctness of the format string and va_list arguments.
2346  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2347  *       Use only for procfs, sysfs and similar files, not printk(); please
2348  *       read the documentation (path below) first.
2349  * - 'NF' For a netdev_features_t
2350  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2351  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2352  *            a certain separator (' ' by default):
2353  *              C colon
2354  *              D dash
2355  *              N no separator
2356  *            The maximum supported length is 64 bytes of the input. Consider
2357  *            to use print_hex_dump() for the larger input.
2358  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2359  *           (default assumed to be phys_addr_t, passed by reference)
2360  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2361  * - 'D[234]' Same as 'd' but for a struct file
2362  * - 'g' For block_device name (gendisk + partition number)
2363  * - 't[RT][dt][r][s]' For time and date as represented by:
2364  *      R    struct rtc_time
2365  *      T    time64_t
2366  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2367  *       (legacy clock framework) of the clock
2368  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2369  *        (legacy clock framework) of the clock
2370  * - 'G' For flags to be printed as a collection of symbolic strings that would
2371  *       construct the specific value. Supported flags given by option:
2372  *       p page flags (see struct page) given as pointer to unsigned long
2373  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2374  *       v vma flags (VM_*) given as pointer to unsigned long
2375  * - 'OF[fnpPcCF]'  For a device tree object
2376  *                  Without any optional arguments prints the full_name
2377  *                  f device node full_name
2378  *                  n device node name
2379  *                  p device node phandle
2380  *                  P device node path spec (name + @unit)
2381  *                  F device node flags
2382  *                  c major compatible string
2383  *                  C full compatible string
2384  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2385  *		Without an option prints the full name of the node
2386  *		f full name
2387  *		P node name, including a possible unit address
2388  * - 'x' For printing the address unmodified. Equivalent to "%lx".
2389  *       Please read the documentation (path below) before using!
2390  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2391  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2392  *           or user (u) memory to probe, and:
2393  *              s a string, equivalent to "%s" on direct vsnprintf() use
2394  *
2395  * ** When making changes please also update:
2396  *	Documentation/core-api/printk-formats.rst
2397  *
2398  * Note: The default behaviour (unadorned %p) is to hash the address,
2399  * rendering it useful as a unique identifier.
2400  *
2401  * There is also a '%pA' format specifier, but it is only intended to be used
2402  * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2403  * See rust/kernel/print.rs for details.
2404  */
2405 static noinline_for_stack
2406 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2407 	      struct printf_spec spec)
2408 {
2409 	switch (*fmt) {
2410 	case 'S':
2411 	case 's':
2412 		ptr = dereference_symbol_descriptor(ptr);
2413 		fallthrough;
2414 	case 'B':
2415 		return symbol_string(buf, end, ptr, spec, fmt);
2416 	case 'R':
2417 	case 'r':
2418 		return resource_string(buf, end, ptr, spec, fmt);
2419 	case 'h':
2420 		return hex_string(buf, end, ptr, spec, fmt);
2421 	case 'b':
2422 		switch (fmt[1]) {
2423 		case 'l':
2424 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2425 		default:
2426 			return bitmap_string(buf, end, ptr, spec, fmt);
2427 		}
2428 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2429 	case 'm':			/* Contiguous: 000102030405 */
2430 					/* [mM]F (FDDI) */
2431 					/* [mM]R (Reverse order; Bluetooth) */
2432 		return mac_address_string(buf, end, ptr, spec, fmt);
2433 	case 'I':			/* Formatted IP supported
2434 					 * 4:	1.2.3.4
2435 					 * 6:	0001:0203:...:0708
2436 					 * 6c:	1::708 or 1::1.2.3.4
2437 					 */
2438 	case 'i':			/* Contiguous:
2439 					 * 4:	001.002.003.004
2440 					 * 6:   000102...0f
2441 					 */
2442 		return ip_addr_string(buf, end, ptr, spec, fmt);
2443 	case 'E':
2444 		return escaped_string(buf, end, ptr, spec, fmt);
2445 	case 'U':
2446 		return uuid_string(buf, end, ptr, spec, fmt);
2447 	case 'V':
2448 		return va_format(buf, end, ptr, spec, fmt);
2449 	case 'K':
2450 		return restricted_pointer(buf, end, ptr, spec);
2451 	case 'N':
2452 		return netdev_bits(buf, end, ptr, spec, fmt);
2453 	case '4':
2454 		return fourcc_string(buf, end, ptr, spec, fmt);
2455 	case 'a':
2456 		return address_val(buf, end, ptr, spec, fmt);
2457 	case 'd':
2458 		return dentry_name(buf, end, ptr, spec, fmt);
2459 	case 't':
2460 		return time_and_date(buf, end, ptr, spec, fmt);
2461 	case 'C':
2462 		return clock(buf, end, ptr, spec, fmt);
2463 	case 'D':
2464 		return file_dentry_name(buf, end, ptr, spec, fmt);
2465 #ifdef CONFIG_BLOCK
2466 	case 'g':
2467 		return bdev_name(buf, end, ptr, spec, fmt);
2468 #endif
2469 
2470 	case 'G':
2471 		return flags_string(buf, end, ptr, spec, fmt);
2472 	case 'O':
2473 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2474 	case 'f':
2475 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2476 	case 'A':
2477 		if (!IS_ENABLED(CONFIG_RUST)) {
2478 			WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2479 			return error_string(buf, end, "(%pA?)", spec);
2480 		}
2481 		return rust_fmt_argument(buf, end, ptr);
2482 	case 'x':
2483 		return pointer_string(buf, end, ptr, spec);
2484 	case 'e':
2485 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2486 		if (!IS_ERR(ptr))
2487 			return default_pointer(buf, end, ptr, spec);
2488 		return err_ptr(buf, end, ptr, spec);
2489 	case 'u':
2490 	case 'k':
2491 		switch (fmt[1]) {
2492 		case 's':
2493 			return string(buf, end, ptr, spec);
2494 		default:
2495 			return error_string(buf, end, "(einval)", spec);
2496 		}
2497 	default:
2498 		return default_pointer(buf, end, ptr, spec);
2499 	}
2500 }
2501 
2502 /*
2503  * Helper function to decode printf style format.
2504  * Each call decode a token from the format and return the
2505  * number of characters read (or likely the delta where it wants
2506  * to go on the next call).
2507  * The decoded token is returned through the parameters
2508  *
2509  * 'h', 'l', or 'L' for integer fields
2510  * 'z' support added 23/7/1999 S.H.
2511  * 'z' changed to 'Z' --davidm 1/25/99
2512  * 'Z' changed to 'z' --adobriyan 2017-01-25
2513  * 't' added for ptrdiff_t
2514  *
2515  * @fmt: the format string
2516  * @type of the token returned
2517  * @flags: various flags such as +, -, # tokens..
2518  * @field_width: overwritten width
2519  * @base: base of the number (octal, hex, ...)
2520  * @precision: precision of a number
2521  * @qualifier: qualifier of a number (long, size_t, ...)
2522  */
2523 static noinline_for_stack
2524 int format_decode(const char *fmt, struct printf_spec *spec)
2525 {
2526 	const char *start = fmt;
2527 	char qualifier;
2528 
2529 	/* we finished early by reading the field width */
2530 	if (spec->type == FORMAT_TYPE_WIDTH) {
2531 		if (spec->field_width < 0) {
2532 			spec->field_width = -spec->field_width;
2533 			spec->flags |= LEFT;
2534 		}
2535 		spec->type = FORMAT_TYPE_NONE;
2536 		goto precision;
2537 	}
2538 
2539 	/* we finished early by reading the precision */
2540 	if (spec->type == FORMAT_TYPE_PRECISION) {
2541 		if (spec->precision < 0)
2542 			spec->precision = 0;
2543 
2544 		spec->type = FORMAT_TYPE_NONE;
2545 		goto qualifier;
2546 	}
2547 
2548 	/* By default */
2549 	spec->type = FORMAT_TYPE_NONE;
2550 
2551 	for (; *fmt ; ++fmt) {
2552 		if (*fmt == '%')
2553 			break;
2554 	}
2555 
2556 	/* Return the current non-format string */
2557 	if (fmt != start || !*fmt)
2558 		return fmt - start;
2559 
2560 	/* Process flags */
2561 	spec->flags = 0;
2562 
2563 	while (1) { /* this also skips first '%' */
2564 		bool found = true;
2565 
2566 		++fmt;
2567 
2568 		switch (*fmt) {
2569 		case '-': spec->flags |= LEFT;    break;
2570 		case '+': spec->flags |= PLUS;    break;
2571 		case ' ': spec->flags |= SPACE;   break;
2572 		case '#': spec->flags |= SPECIAL; break;
2573 		case '0': spec->flags |= ZEROPAD; break;
2574 		default:  found = false;
2575 		}
2576 
2577 		if (!found)
2578 			break;
2579 	}
2580 
2581 	/* get field width */
2582 	spec->field_width = -1;
2583 
2584 	if (isdigit(*fmt))
2585 		spec->field_width = skip_atoi(&fmt);
2586 	else if (*fmt == '*') {
2587 		/* it's the next argument */
2588 		spec->type = FORMAT_TYPE_WIDTH;
2589 		return ++fmt - start;
2590 	}
2591 
2592 precision:
2593 	/* get the precision */
2594 	spec->precision = -1;
2595 	if (*fmt == '.') {
2596 		++fmt;
2597 		if (isdigit(*fmt)) {
2598 			spec->precision = skip_atoi(&fmt);
2599 			if (spec->precision < 0)
2600 				spec->precision = 0;
2601 		} else if (*fmt == '*') {
2602 			/* it's the next argument */
2603 			spec->type = FORMAT_TYPE_PRECISION;
2604 			return ++fmt - start;
2605 		}
2606 	}
2607 
2608 qualifier:
2609 	/* get the conversion qualifier */
2610 	qualifier = 0;
2611 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2612 	    *fmt == 'z' || *fmt == 't') {
2613 		qualifier = *fmt++;
2614 		if (unlikely(qualifier == *fmt)) {
2615 			if (qualifier == 'l') {
2616 				qualifier = 'L';
2617 				++fmt;
2618 			} else if (qualifier == 'h') {
2619 				qualifier = 'H';
2620 				++fmt;
2621 			}
2622 		}
2623 	}
2624 
2625 	/* default base */
2626 	spec->base = 10;
2627 	switch (*fmt) {
2628 	case 'c':
2629 		spec->type = FORMAT_TYPE_CHAR;
2630 		return ++fmt - start;
2631 
2632 	case 's':
2633 		spec->type = FORMAT_TYPE_STR;
2634 		return ++fmt - start;
2635 
2636 	case 'p':
2637 		spec->type = FORMAT_TYPE_PTR;
2638 		return ++fmt - start;
2639 
2640 	case '%':
2641 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2642 		return ++fmt - start;
2643 
2644 	/* integer number formats - set up the flags and "break" */
2645 	case 'o':
2646 		spec->base = 8;
2647 		break;
2648 
2649 	case 'x':
2650 		spec->flags |= SMALL;
2651 		fallthrough;
2652 
2653 	case 'X':
2654 		spec->base = 16;
2655 		break;
2656 
2657 	case 'd':
2658 	case 'i':
2659 		spec->flags |= SIGN;
2660 		break;
2661 	case 'u':
2662 		break;
2663 
2664 	case 'n':
2665 		/*
2666 		 * Since %n poses a greater security risk than
2667 		 * utility, treat it as any other invalid or
2668 		 * unsupported format specifier.
2669 		 */
2670 		fallthrough;
2671 
2672 	default:
2673 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2674 		spec->type = FORMAT_TYPE_INVALID;
2675 		return fmt - start;
2676 	}
2677 
2678 	if (qualifier == 'L')
2679 		spec->type = FORMAT_TYPE_LONG_LONG;
2680 	else if (qualifier == 'l') {
2681 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2682 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2683 	} else if (qualifier == 'z') {
2684 		spec->type = FORMAT_TYPE_SIZE_T;
2685 	} else if (qualifier == 't') {
2686 		spec->type = FORMAT_TYPE_PTRDIFF;
2687 	} else if (qualifier == 'H') {
2688 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2689 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2690 	} else if (qualifier == 'h') {
2691 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2692 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2693 	} else {
2694 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2695 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2696 	}
2697 
2698 	return ++fmt - start;
2699 }
2700 
2701 static void
2702 set_field_width(struct printf_spec *spec, int width)
2703 {
2704 	spec->field_width = width;
2705 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2706 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2707 	}
2708 }
2709 
2710 static void
2711 set_precision(struct printf_spec *spec, int prec)
2712 {
2713 	spec->precision = prec;
2714 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2715 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2716 	}
2717 }
2718 
2719 /**
2720  * vsnprintf - Format a string and place it in a buffer
2721  * @buf: The buffer to place the result into
2722  * @size: The size of the buffer, including the trailing null space
2723  * @fmt: The format string to use
2724  * @args: Arguments for the format string
2725  *
2726  * This function generally follows C99 vsnprintf, but has some
2727  * extensions and a few limitations:
2728  *
2729  *  - ``%n`` is unsupported
2730  *  - ``%p*`` is handled by pointer()
2731  *
2732  * See pointer() or Documentation/core-api/printk-formats.rst for more
2733  * extensive description.
2734  *
2735  * **Please update the documentation in both places when making changes**
2736  *
2737  * The return value is the number of characters which would
2738  * be generated for the given input, excluding the trailing
2739  * '\0', as per ISO C99. If you want to have the exact
2740  * number of characters written into @buf as return value
2741  * (not including the trailing '\0'), use vscnprintf(). If the
2742  * return is greater than or equal to @size, the resulting
2743  * string is truncated.
2744  *
2745  * If you're not already dealing with a va_list consider using snprintf().
2746  */
2747 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2748 {
2749 	unsigned long long num;
2750 	char *str, *end;
2751 	struct printf_spec spec = {0};
2752 
2753 	/* Reject out-of-range values early.  Large positive sizes are
2754 	   used for unknown buffer sizes. */
2755 	if (WARN_ON_ONCE(size > INT_MAX))
2756 		return 0;
2757 
2758 	str = buf;
2759 	end = buf + size;
2760 
2761 	/* Make sure end is always >= buf */
2762 	if (end < buf) {
2763 		end = ((void *)-1);
2764 		size = end - buf;
2765 	}
2766 
2767 	while (*fmt) {
2768 		const char *old_fmt = fmt;
2769 		int read = format_decode(fmt, &spec);
2770 
2771 		fmt += read;
2772 
2773 		switch (spec.type) {
2774 		case FORMAT_TYPE_NONE: {
2775 			int copy = read;
2776 			if (str < end) {
2777 				if (copy > end - str)
2778 					copy = end - str;
2779 				memcpy(str, old_fmt, copy);
2780 			}
2781 			str += read;
2782 			break;
2783 		}
2784 
2785 		case FORMAT_TYPE_WIDTH:
2786 			set_field_width(&spec, va_arg(args, int));
2787 			break;
2788 
2789 		case FORMAT_TYPE_PRECISION:
2790 			set_precision(&spec, va_arg(args, int));
2791 			break;
2792 
2793 		case FORMAT_TYPE_CHAR: {
2794 			char c;
2795 
2796 			if (!(spec.flags & LEFT)) {
2797 				while (--spec.field_width > 0) {
2798 					if (str < end)
2799 						*str = ' ';
2800 					++str;
2801 
2802 				}
2803 			}
2804 			c = (unsigned char) va_arg(args, int);
2805 			if (str < end)
2806 				*str = c;
2807 			++str;
2808 			while (--spec.field_width > 0) {
2809 				if (str < end)
2810 					*str = ' ';
2811 				++str;
2812 			}
2813 			break;
2814 		}
2815 
2816 		case FORMAT_TYPE_STR:
2817 			str = string(str, end, va_arg(args, char *), spec);
2818 			break;
2819 
2820 		case FORMAT_TYPE_PTR:
2821 			str = pointer(fmt, str, end, va_arg(args, void *),
2822 				      spec);
2823 			while (isalnum(*fmt))
2824 				fmt++;
2825 			break;
2826 
2827 		case FORMAT_TYPE_PERCENT_CHAR:
2828 			if (str < end)
2829 				*str = '%';
2830 			++str;
2831 			break;
2832 
2833 		case FORMAT_TYPE_INVALID:
2834 			/*
2835 			 * Presumably the arguments passed gcc's type
2836 			 * checking, but there is no safe or sane way
2837 			 * for us to continue parsing the format and
2838 			 * fetching from the va_list; the remaining
2839 			 * specifiers and arguments would be out of
2840 			 * sync.
2841 			 */
2842 			goto out;
2843 
2844 		default:
2845 			switch (spec.type) {
2846 			case FORMAT_TYPE_LONG_LONG:
2847 				num = va_arg(args, long long);
2848 				break;
2849 			case FORMAT_TYPE_ULONG:
2850 				num = va_arg(args, unsigned long);
2851 				break;
2852 			case FORMAT_TYPE_LONG:
2853 				num = va_arg(args, long);
2854 				break;
2855 			case FORMAT_TYPE_SIZE_T:
2856 				if (spec.flags & SIGN)
2857 					num = va_arg(args, ssize_t);
2858 				else
2859 					num = va_arg(args, size_t);
2860 				break;
2861 			case FORMAT_TYPE_PTRDIFF:
2862 				num = va_arg(args, ptrdiff_t);
2863 				break;
2864 			case FORMAT_TYPE_UBYTE:
2865 				num = (unsigned char) va_arg(args, int);
2866 				break;
2867 			case FORMAT_TYPE_BYTE:
2868 				num = (signed char) va_arg(args, int);
2869 				break;
2870 			case FORMAT_TYPE_USHORT:
2871 				num = (unsigned short) va_arg(args, int);
2872 				break;
2873 			case FORMAT_TYPE_SHORT:
2874 				num = (short) va_arg(args, int);
2875 				break;
2876 			case FORMAT_TYPE_INT:
2877 				num = (int) va_arg(args, int);
2878 				break;
2879 			default:
2880 				num = va_arg(args, unsigned int);
2881 			}
2882 
2883 			str = number(str, end, num, spec);
2884 		}
2885 	}
2886 
2887 out:
2888 	if (size > 0) {
2889 		if (str < end)
2890 			*str = '\0';
2891 		else
2892 			end[-1] = '\0';
2893 	}
2894 
2895 	/* the trailing null byte doesn't count towards the total */
2896 	return str-buf;
2897 
2898 }
2899 EXPORT_SYMBOL(vsnprintf);
2900 
2901 /**
2902  * vscnprintf - Format a string and place it in a buffer
2903  * @buf: The buffer to place the result into
2904  * @size: The size of the buffer, including the trailing null space
2905  * @fmt: The format string to use
2906  * @args: Arguments for the format string
2907  *
2908  * The return value is the number of characters which have been written into
2909  * the @buf not including the trailing '\0'. If @size is == 0 the function
2910  * returns 0.
2911  *
2912  * If you're not already dealing with a va_list consider using scnprintf().
2913  *
2914  * See the vsnprintf() documentation for format string extensions over C99.
2915  */
2916 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2917 {
2918 	int i;
2919 
2920 	if (unlikely(!size))
2921 		return 0;
2922 
2923 	i = vsnprintf(buf, size, fmt, args);
2924 
2925 	if (likely(i < size))
2926 		return i;
2927 
2928 	return size - 1;
2929 }
2930 EXPORT_SYMBOL(vscnprintf);
2931 
2932 /**
2933  * snprintf - Format a string and place it in a buffer
2934  * @buf: The buffer to place the result into
2935  * @size: The size of the buffer, including the trailing null space
2936  * @fmt: The format string to use
2937  * @...: Arguments for the format string
2938  *
2939  * The return value is the number of characters which would be
2940  * generated for the given input, excluding the trailing null,
2941  * as per ISO C99.  If the return is greater than or equal to
2942  * @size, the resulting string is truncated.
2943  *
2944  * See the vsnprintf() documentation for format string extensions over C99.
2945  */
2946 int snprintf(char *buf, size_t size, const char *fmt, ...)
2947 {
2948 	va_list args;
2949 	int i;
2950 
2951 	va_start(args, fmt);
2952 	i = vsnprintf(buf, size, fmt, args);
2953 	va_end(args);
2954 
2955 	return i;
2956 }
2957 EXPORT_SYMBOL(snprintf);
2958 
2959 /**
2960  * scnprintf - Format a string and place it in a buffer
2961  * @buf: The buffer to place the result into
2962  * @size: The size of the buffer, including the trailing null space
2963  * @fmt: The format string to use
2964  * @...: Arguments for the format string
2965  *
2966  * The return value is the number of characters written into @buf not including
2967  * the trailing '\0'. If @size is == 0 the function returns 0.
2968  */
2969 
2970 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2971 {
2972 	va_list args;
2973 	int i;
2974 
2975 	va_start(args, fmt);
2976 	i = vscnprintf(buf, size, fmt, args);
2977 	va_end(args);
2978 
2979 	return i;
2980 }
2981 EXPORT_SYMBOL(scnprintf);
2982 
2983 /**
2984  * vsprintf - Format a string and place it in a buffer
2985  * @buf: The buffer to place the result into
2986  * @fmt: The format string to use
2987  * @args: Arguments for the format string
2988  *
2989  * The function returns the number of characters written
2990  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2991  * buffer overflows.
2992  *
2993  * If you're not already dealing with a va_list consider using sprintf().
2994  *
2995  * See the vsnprintf() documentation for format string extensions over C99.
2996  */
2997 int vsprintf(char *buf, const char *fmt, va_list args)
2998 {
2999 	return vsnprintf(buf, INT_MAX, fmt, args);
3000 }
3001 EXPORT_SYMBOL(vsprintf);
3002 
3003 /**
3004  * sprintf - Format a string and place it in a buffer
3005  * @buf: The buffer to place the result into
3006  * @fmt: The format string to use
3007  * @...: Arguments for the format string
3008  *
3009  * The function returns the number of characters written
3010  * into @buf. Use snprintf() or scnprintf() in order to avoid
3011  * buffer overflows.
3012  *
3013  * See the vsnprintf() documentation for format string extensions over C99.
3014  */
3015 int sprintf(char *buf, const char *fmt, ...)
3016 {
3017 	va_list args;
3018 	int i;
3019 
3020 	va_start(args, fmt);
3021 	i = vsnprintf(buf, INT_MAX, fmt, args);
3022 	va_end(args);
3023 
3024 	return i;
3025 }
3026 EXPORT_SYMBOL(sprintf);
3027 
3028 #ifdef CONFIG_BINARY_PRINTF
3029 /*
3030  * bprintf service:
3031  * vbin_printf() - VA arguments to binary data
3032  * bstr_printf() - Binary data to text string
3033  */
3034 
3035 /**
3036  * vbin_printf - Parse a format string and place args' binary value in a buffer
3037  * @bin_buf: The buffer to place args' binary value
3038  * @size: The size of the buffer(by words(32bits), not characters)
3039  * @fmt: The format string to use
3040  * @args: Arguments for the format string
3041  *
3042  * The format follows C99 vsnprintf, except %n is ignored, and its argument
3043  * is skipped.
3044  *
3045  * The return value is the number of words(32bits) which would be generated for
3046  * the given input.
3047  *
3048  * NOTE:
3049  * If the return value is greater than @size, the resulting bin_buf is NOT
3050  * valid for bstr_printf().
3051  */
3052 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3053 {
3054 	struct printf_spec spec = {0};
3055 	char *str, *end;
3056 	int width;
3057 
3058 	str = (char *)bin_buf;
3059 	end = (char *)(bin_buf + size);
3060 
3061 #define save_arg(type)							\
3062 ({									\
3063 	unsigned long long value;					\
3064 	if (sizeof(type) == 8) {					\
3065 		unsigned long long val8;				\
3066 		str = PTR_ALIGN(str, sizeof(u32));			\
3067 		val8 = va_arg(args, unsigned long long);		\
3068 		if (str + sizeof(type) <= end) {			\
3069 			*(u32 *)str = *(u32 *)&val8;			\
3070 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
3071 		}							\
3072 		value = val8;						\
3073 	} else {							\
3074 		unsigned int val4;					\
3075 		str = PTR_ALIGN(str, sizeof(type));			\
3076 		val4 = va_arg(args, int);				\
3077 		if (str + sizeof(type) <= end)				\
3078 			*(typeof(type) *)str = (type)(long)val4;	\
3079 		value = (unsigned long long)val4;			\
3080 	}								\
3081 	str += sizeof(type);						\
3082 	value;								\
3083 })
3084 
3085 	while (*fmt) {
3086 		int read = format_decode(fmt, &spec);
3087 
3088 		fmt += read;
3089 
3090 		switch (spec.type) {
3091 		case FORMAT_TYPE_NONE:
3092 		case FORMAT_TYPE_PERCENT_CHAR:
3093 			break;
3094 		case FORMAT_TYPE_INVALID:
3095 			goto out;
3096 
3097 		case FORMAT_TYPE_WIDTH:
3098 		case FORMAT_TYPE_PRECISION:
3099 			width = (int)save_arg(int);
3100 			/* Pointers may require the width */
3101 			if (*fmt == 'p')
3102 				set_field_width(&spec, width);
3103 			break;
3104 
3105 		case FORMAT_TYPE_CHAR:
3106 			save_arg(char);
3107 			break;
3108 
3109 		case FORMAT_TYPE_STR: {
3110 			const char *save_str = va_arg(args, char *);
3111 			const char *err_msg;
3112 			size_t len;
3113 
3114 			err_msg = check_pointer_msg(save_str);
3115 			if (err_msg)
3116 				save_str = err_msg;
3117 
3118 			len = strlen(save_str) + 1;
3119 			if (str + len < end)
3120 				memcpy(str, save_str, len);
3121 			str += len;
3122 			break;
3123 		}
3124 
3125 		case FORMAT_TYPE_PTR:
3126 			/* Dereferenced pointers must be done now */
3127 			switch (*fmt) {
3128 			/* Dereference of functions is still OK */
3129 			case 'S':
3130 			case 's':
3131 			case 'x':
3132 			case 'K':
3133 			case 'e':
3134 				save_arg(void *);
3135 				break;
3136 			default:
3137 				if (!isalnum(*fmt)) {
3138 					save_arg(void *);
3139 					break;
3140 				}
3141 				str = pointer(fmt, str, end, va_arg(args, void *),
3142 					      spec);
3143 				if (str + 1 < end)
3144 					*str++ = '\0';
3145 				else
3146 					end[-1] = '\0'; /* Must be nul terminated */
3147 			}
3148 			/* skip all alphanumeric pointer suffixes */
3149 			while (isalnum(*fmt))
3150 				fmt++;
3151 			break;
3152 
3153 		default:
3154 			switch (spec.type) {
3155 
3156 			case FORMAT_TYPE_LONG_LONG:
3157 				save_arg(long long);
3158 				break;
3159 			case FORMAT_TYPE_ULONG:
3160 			case FORMAT_TYPE_LONG:
3161 				save_arg(unsigned long);
3162 				break;
3163 			case FORMAT_TYPE_SIZE_T:
3164 				save_arg(size_t);
3165 				break;
3166 			case FORMAT_TYPE_PTRDIFF:
3167 				save_arg(ptrdiff_t);
3168 				break;
3169 			case FORMAT_TYPE_UBYTE:
3170 			case FORMAT_TYPE_BYTE:
3171 				save_arg(char);
3172 				break;
3173 			case FORMAT_TYPE_USHORT:
3174 			case FORMAT_TYPE_SHORT:
3175 				save_arg(short);
3176 				break;
3177 			default:
3178 				save_arg(int);
3179 			}
3180 		}
3181 	}
3182 
3183 out:
3184 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3185 #undef save_arg
3186 }
3187 EXPORT_SYMBOL_GPL(vbin_printf);
3188 
3189 /**
3190  * bstr_printf - Format a string from binary arguments and place it in a buffer
3191  * @buf: The buffer to place the result into
3192  * @size: The size of the buffer, including the trailing null space
3193  * @fmt: The format string to use
3194  * @bin_buf: Binary arguments for the format string
3195  *
3196  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3197  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3198  * a binary buffer that generated by vbin_printf.
3199  *
3200  * The format follows C99 vsnprintf, but has some extensions:
3201  *  see vsnprintf comment for details.
3202  *
3203  * The return value is the number of characters which would
3204  * be generated for the given input, excluding the trailing
3205  * '\0', as per ISO C99. If you want to have the exact
3206  * number of characters written into @buf as return value
3207  * (not including the trailing '\0'), use vscnprintf(). If the
3208  * return is greater than or equal to @size, the resulting
3209  * string is truncated.
3210  */
3211 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3212 {
3213 	struct printf_spec spec = {0};
3214 	char *str, *end;
3215 	const char *args = (const char *)bin_buf;
3216 
3217 	if (WARN_ON_ONCE(size > INT_MAX))
3218 		return 0;
3219 
3220 	str = buf;
3221 	end = buf + size;
3222 
3223 #define get_arg(type)							\
3224 ({									\
3225 	typeof(type) value;						\
3226 	if (sizeof(type) == 8) {					\
3227 		args = PTR_ALIGN(args, sizeof(u32));			\
3228 		*(u32 *)&value = *(u32 *)args;				\
3229 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3230 	} else {							\
3231 		args = PTR_ALIGN(args, sizeof(type));			\
3232 		value = *(typeof(type) *)args;				\
3233 	}								\
3234 	args += sizeof(type);						\
3235 	value;								\
3236 })
3237 
3238 	/* Make sure end is always >= buf */
3239 	if (end < buf) {
3240 		end = ((void *)-1);
3241 		size = end - buf;
3242 	}
3243 
3244 	while (*fmt) {
3245 		const char *old_fmt = fmt;
3246 		int read = format_decode(fmt, &spec);
3247 
3248 		fmt += read;
3249 
3250 		switch (spec.type) {
3251 		case FORMAT_TYPE_NONE: {
3252 			int copy = read;
3253 			if (str < end) {
3254 				if (copy > end - str)
3255 					copy = end - str;
3256 				memcpy(str, old_fmt, copy);
3257 			}
3258 			str += read;
3259 			break;
3260 		}
3261 
3262 		case FORMAT_TYPE_WIDTH:
3263 			set_field_width(&spec, get_arg(int));
3264 			break;
3265 
3266 		case FORMAT_TYPE_PRECISION:
3267 			set_precision(&spec, get_arg(int));
3268 			break;
3269 
3270 		case FORMAT_TYPE_CHAR: {
3271 			char c;
3272 
3273 			if (!(spec.flags & LEFT)) {
3274 				while (--spec.field_width > 0) {
3275 					if (str < end)
3276 						*str = ' ';
3277 					++str;
3278 				}
3279 			}
3280 			c = (unsigned char) get_arg(char);
3281 			if (str < end)
3282 				*str = c;
3283 			++str;
3284 			while (--spec.field_width > 0) {
3285 				if (str < end)
3286 					*str = ' ';
3287 				++str;
3288 			}
3289 			break;
3290 		}
3291 
3292 		case FORMAT_TYPE_STR: {
3293 			const char *str_arg = args;
3294 			args += strlen(str_arg) + 1;
3295 			str = string(str, end, (char *)str_arg, spec);
3296 			break;
3297 		}
3298 
3299 		case FORMAT_TYPE_PTR: {
3300 			bool process = false;
3301 			int copy, len;
3302 			/* Non function dereferences were already done */
3303 			switch (*fmt) {
3304 			case 'S':
3305 			case 's':
3306 			case 'x':
3307 			case 'K':
3308 			case 'e':
3309 				process = true;
3310 				break;
3311 			default:
3312 				if (!isalnum(*fmt)) {
3313 					process = true;
3314 					break;
3315 				}
3316 				/* Pointer dereference was already processed */
3317 				if (str < end) {
3318 					len = copy = strlen(args);
3319 					if (copy > end - str)
3320 						copy = end - str;
3321 					memcpy(str, args, copy);
3322 					str += len;
3323 					args += len + 1;
3324 				}
3325 			}
3326 			if (process)
3327 				str = pointer(fmt, str, end, get_arg(void *), spec);
3328 
3329 			while (isalnum(*fmt))
3330 				fmt++;
3331 			break;
3332 		}
3333 
3334 		case FORMAT_TYPE_PERCENT_CHAR:
3335 			if (str < end)
3336 				*str = '%';
3337 			++str;
3338 			break;
3339 
3340 		case FORMAT_TYPE_INVALID:
3341 			goto out;
3342 
3343 		default: {
3344 			unsigned long long num;
3345 
3346 			switch (spec.type) {
3347 
3348 			case FORMAT_TYPE_LONG_LONG:
3349 				num = get_arg(long long);
3350 				break;
3351 			case FORMAT_TYPE_ULONG:
3352 			case FORMAT_TYPE_LONG:
3353 				num = get_arg(unsigned long);
3354 				break;
3355 			case FORMAT_TYPE_SIZE_T:
3356 				num = get_arg(size_t);
3357 				break;
3358 			case FORMAT_TYPE_PTRDIFF:
3359 				num = get_arg(ptrdiff_t);
3360 				break;
3361 			case FORMAT_TYPE_UBYTE:
3362 				num = get_arg(unsigned char);
3363 				break;
3364 			case FORMAT_TYPE_BYTE:
3365 				num = get_arg(signed char);
3366 				break;
3367 			case FORMAT_TYPE_USHORT:
3368 				num = get_arg(unsigned short);
3369 				break;
3370 			case FORMAT_TYPE_SHORT:
3371 				num = get_arg(short);
3372 				break;
3373 			case FORMAT_TYPE_UINT:
3374 				num = get_arg(unsigned int);
3375 				break;
3376 			default:
3377 				num = get_arg(int);
3378 			}
3379 
3380 			str = number(str, end, num, spec);
3381 		} /* default: */
3382 		} /* switch(spec.type) */
3383 	} /* while(*fmt) */
3384 
3385 out:
3386 	if (size > 0) {
3387 		if (str < end)
3388 			*str = '\0';
3389 		else
3390 			end[-1] = '\0';
3391 	}
3392 
3393 #undef get_arg
3394 
3395 	/* the trailing null byte doesn't count towards the total */
3396 	return str - buf;
3397 }
3398 EXPORT_SYMBOL_GPL(bstr_printf);
3399 
3400 /**
3401  * bprintf - Parse a format string and place args' binary value in a buffer
3402  * @bin_buf: The buffer to place args' binary value
3403  * @size: The size of the buffer(by words(32bits), not characters)
3404  * @fmt: The format string to use
3405  * @...: Arguments for the format string
3406  *
3407  * The function returns the number of words(u32) written
3408  * into @bin_buf.
3409  */
3410 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3411 {
3412 	va_list args;
3413 	int ret;
3414 
3415 	va_start(args, fmt);
3416 	ret = vbin_printf(bin_buf, size, fmt, args);
3417 	va_end(args);
3418 
3419 	return ret;
3420 }
3421 EXPORT_SYMBOL_GPL(bprintf);
3422 
3423 #endif /* CONFIG_BINARY_PRINTF */
3424 
3425 /**
3426  * vsscanf - Unformat a buffer into a list of arguments
3427  * @buf:	input buffer
3428  * @fmt:	format of buffer
3429  * @args:	arguments
3430  */
3431 int vsscanf(const char *buf, const char *fmt, va_list args)
3432 {
3433 	const char *str = buf;
3434 	char *next;
3435 	char digit;
3436 	int num = 0;
3437 	u8 qualifier;
3438 	unsigned int base;
3439 	union {
3440 		long long s;
3441 		unsigned long long u;
3442 	} val;
3443 	s16 field_width;
3444 	bool is_sign;
3445 
3446 	while (*fmt) {
3447 		/* skip any white space in format */
3448 		/* white space in format matches any amount of
3449 		 * white space, including none, in the input.
3450 		 */
3451 		if (isspace(*fmt)) {
3452 			fmt = skip_spaces(++fmt);
3453 			str = skip_spaces(str);
3454 		}
3455 
3456 		/* anything that is not a conversion must match exactly */
3457 		if (*fmt != '%' && *fmt) {
3458 			if (*fmt++ != *str++)
3459 				break;
3460 			continue;
3461 		}
3462 
3463 		if (!*fmt)
3464 			break;
3465 		++fmt;
3466 
3467 		/* skip this conversion.
3468 		 * advance both strings to next white space
3469 		 */
3470 		if (*fmt == '*') {
3471 			if (!*str)
3472 				break;
3473 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3474 				/* '%*[' not yet supported, invalid format */
3475 				if (*fmt == '[')
3476 					return num;
3477 				fmt++;
3478 			}
3479 			while (!isspace(*str) && *str)
3480 				str++;
3481 			continue;
3482 		}
3483 
3484 		/* get field width */
3485 		field_width = -1;
3486 		if (isdigit(*fmt)) {
3487 			field_width = skip_atoi(&fmt);
3488 			if (field_width <= 0)
3489 				break;
3490 		}
3491 
3492 		/* get conversion qualifier */
3493 		qualifier = -1;
3494 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3495 		    *fmt == 'z') {
3496 			qualifier = *fmt++;
3497 			if (unlikely(qualifier == *fmt)) {
3498 				if (qualifier == 'h') {
3499 					qualifier = 'H';
3500 					fmt++;
3501 				} else if (qualifier == 'l') {
3502 					qualifier = 'L';
3503 					fmt++;
3504 				}
3505 			}
3506 		}
3507 
3508 		if (!*fmt)
3509 			break;
3510 
3511 		if (*fmt == 'n') {
3512 			/* return number of characters read so far */
3513 			*va_arg(args, int *) = str - buf;
3514 			++fmt;
3515 			continue;
3516 		}
3517 
3518 		if (!*str)
3519 			break;
3520 
3521 		base = 10;
3522 		is_sign = false;
3523 
3524 		switch (*fmt++) {
3525 		case 'c':
3526 		{
3527 			char *s = (char *)va_arg(args, char*);
3528 			if (field_width == -1)
3529 				field_width = 1;
3530 			do {
3531 				*s++ = *str++;
3532 			} while (--field_width > 0 && *str);
3533 			num++;
3534 		}
3535 		continue;
3536 		case 's':
3537 		{
3538 			char *s = (char *)va_arg(args, char *);
3539 			if (field_width == -1)
3540 				field_width = SHRT_MAX;
3541 			/* first, skip leading white space in buffer */
3542 			str = skip_spaces(str);
3543 
3544 			/* now copy until next white space */
3545 			while (*str && !isspace(*str) && field_width--)
3546 				*s++ = *str++;
3547 			*s = '\0';
3548 			num++;
3549 		}
3550 		continue;
3551 		/*
3552 		 * Warning: This implementation of the '[' conversion specifier
3553 		 * deviates from its glibc counterpart in the following ways:
3554 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3555 		 *     character
3556 		 * (2) It cannot match the closing bracket ']' itself
3557 		 * (3) A field width is required
3558 		 * (4) '%*[' (discard matching input) is currently not supported
3559 		 *
3560 		 * Example usage:
3561 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3562 		 *		buf1, buf2, buf3);
3563 		 * if (ret < 3)
3564 		 *    // etc..
3565 		 */
3566 		case '[':
3567 		{
3568 			char *s = (char *)va_arg(args, char *);
3569 			DECLARE_BITMAP(set, 256) = {0};
3570 			unsigned int len = 0;
3571 			bool negate = (*fmt == '^');
3572 
3573 			/* field width is required */
3574 			if (field_width == -1)
3575 				return num;
3576 
3577 			if (negate)
3578 				++fmt;
3579 
3580 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3581 				__set_bit((u8)*fmt, set);
3582 
3583 			/* no ']' or no character set found */
3584 			if (!*fmt || !len)
3585 				return num;
3586 			++fmt;
3587 
3588 			if (negate) {
3589 				bitmap_complement(set, set, 256);
3590 				/* exclude null '\0' byte */
3591 				__clear_bit(0, set);
3592 			}
3593 
3594 			/* match must be non-empty */
3595 			if (!test_bit((u8)*str, set))
3596 				return num;
3597 
3598 			while (test_bit((u8)*str, set) && field_width--)
3599 				*s++ = *str++;
3600 			*s = '\0';
3601 			++num;
3602 		}
3603 		continue;
3604 		case 'o':
3605 			base = 8;
3606 			break;
3607 		case 'x':
3608 		case 'X':
3609 			base = 16;
3610 			break;
3611 		case 'i':
3612 			base = 0;
3613 			fallthrough;
3614 		case 'd':
3615 			is_sign = true;
3616 			fallthrough;
3617 		case 'u':
3618 			break;
3619 		case '%':
3620 			/* looking for '%' in str */
3621 			if (*str++ != '%')
3622 				return num;
3623 			continue;
3624 		default:
3625 			/* invalid format; stop here */
3626 			return num;
3627 		}
3628 
3629 		/* have some sort of integer conversion.
3630 		 * first, skip white space in buffer.
3631 		 */
3632 		str = skip_spaces(str);
3633 
3634 		digit = *str;
3635 		if (is_sign && digit == '-') {
3636 			if (field_width == 1)
3637 				break;
3638 
3639 			digit = *(str + 1);
3640 		}
3641 
3642 		if (!digit
3643 		    || (base == 16 && !isxdigit(digit))
3644 		    || (base == 10 && !isdigit(digit))
3645 		    || (base == 8 && !isodigit(digit))
3646 		    || (base == 0 && !isdigit(digit)))
3647 			break;
3648 
3649 		if (is_sign)
3650 			val.s = simple_strntoll(str,
3651 						field_width >= 0 ? field_width : INT_MAX,
3652 						&next, base);
3653 		else
3654 			val.u = simple_strntoull(str,
3655 						 field_width >= 0 ? field_width : INT_MAX,
3656 						 &next, base);
3657 
3658 		switch (qualifier) {
3659 		case 'H':	/* that's 'hh' in format */
3660 			if (is_sign)
3661 				*va_arg(args, signed char *) = val.s;
3662 			else
3663 				*va_arg(args, unsigned char *) = val.u;
3664 			break;
3665 		case 'h':
3666 			if (is_sign)
3667 				*va_arg(args, short *) = val.s;
3668 			else
3669 				*va_arg(args, unsigned short *) = val.u;
3670 			break;
3671 		case 'l':
3672 			if (is_sign)
3673 				*va_arg(args, long *) = val.s;
3674 			else
3675 				*va_arg(args, unsigned long *) = val.u;
3676 			break;
3677 		case 'L':
3678 			if (is_sign)
3679 				*va_arg(args, long long *) = val.s;
3680 			else
3681 				*va_arg(args, unsigned long long *) = val.u;
3682 			break;
3683 		case 'z':
3684 			*va_arg(args, size_t *) = val.u;
3685 			break;
3686 		default:
3687 			if (is_sign)
3688 				*va_arg(args, int *) = val.s;
3689 			else
3690 				*va_arg(args, unsigned int *) = val.u;
3691 			break;
3692 		}
3693 		num++;
3694 
3695 		if (!next)
3696 			break;
3697 		str = next;
3698 	}
3699 
3700 	return num;
3701 }
3702 EXPORT_SYMBOL(vsscanf);
3703 
3704 /**
3705  * sscanf - Unformat a buffer into a list of arguments
3706  * @buf:	input buffer
3707  * @fmt:	formatting of buffer
3708  * @...:	resulting arguments
3709  */
3710 int sscanf(const char *buf, const char *fmt, ...)
3711 {
3712 	va_list args;
3713 	int i;
3714 
3715 	va_start(args, fmt);
3716 	i = vsscanf(buf, fmt, args);
3717 	va_end(args);
3718 
3719 	return i;
3720 }
3721 EXPORT_SYMBOL(sscanf);
3722