xref: /openbmc/linux/lib/vsprintf.c (revision bbaa836b)
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 #ifdef CONFIG_BLOCK
45 #include <linux/blkdev.h>
46 #endif
47 
48 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
49 
50 #include <asm/page.h>		/* for PAGE_SIZE */
51 #include <asm/byteorder.h>	/* cpu_to_le16 */
52 
53 #include <linux/string_helpers.h>
54 #include "kstrtox.h"
55 
56 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
57 {
58 	const char *cp;
59 	unsigned long long result = 0ULL;
60 	size_t prefix_chars;
61 	unsigned int rv;
62 
63 	cp = _parse_integer_fixup_radix(startp, &base);
64 	prefix_chars = cp - startp;
65 	if (prefix_chars < max_chars) {
66 		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
67 		/* FIXME */
68 		cp += (rv & ~KSTRTOX_OVERFLOW);
69 	} else {
70 		/* Field too short for prefix + digit, skip over without converting */
71 		cp = startp + max_chars;
72 	}
73 
74 	if (endp)
75 		*endp = (char *)cp;
76 
77 	return result;
78 }
79 
80 /**
81  * simple_strtoull - convert a string to an unsigned long long
82  * @cp: The start of the string
83  * @endp: A pointer to the end of the parsed string will be placed here
84  * @base: The number base to use
85  *
86  * This function has caveats. Please use kstrtoull instead.
87  */
88 noinline
89 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
90 {
91 	return simple_strntoull(cp, INT_MAX, endp, base);
92 }
93 EXPORT_SYMBOL(simple_strtoull);
94 
95 /**
96  * simple_strtoul - convert a string to an unsigned long
97  * @cp: The start of the string
98  * @endp: A pointer to the end of the parsed string will be placed here
99  * @base: The number base to use
100  *
101  * This function has caveats. Please use kstrtoul instead.
102  */
103 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
104 {
105 	return simple_strtoull(cp, endp, base);
106 }
107 EXPORT_SYMBOL(simple_strtoul);
108 
109 /**
110  * simple_strtol - convert a string to a signed long
111  * @cp: The start of the string
112  * @endp: A pointer to the end of the parsed string will be placed here
113  * @base: The number base to use
114  *
115  * This function has caveats. Please use kstrtol instead.
116  */
117 long simple_strtol(const char *cp, char **endp, unsigned int base)
118 {
119 	if (*cp == '-')
120 		return -simple_strtoul(cp + 1, endp, base);
121 
122 	return simple_strtoul(cp, endp, base);
123 }
124 EXPORT_SYMBOL(simple_strtol);
125 
126 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
127 				 unsigned int base)
128 {
129 	/*
130 	 * simple_strntoull() safely handles receiving max_chars==0 in the
131 	 * case cp[0] == '-' && max_chars == 1.
132 	 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
133 	 * and the content of *cp is irrelevant.
134 	 */
135 	if (*cp == '-' && max_chars > 0)
136 		return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
137 
138 	return simple_strntoull(cp, max_chars, endp, base);
139 }
140 
141 /**
142  * simple_strtoll - convert a string to a signed long long
143  * @cp: The start of the string
144  * @endp: A pointer to the end of the parsed string will be placed here
145  * @base: The number base to use
146  *
147  * This function has caveats. Please use kstrtoll instead.
148  */
149 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
150 {
151 	return simple_strntoll(cp, INT_MAX, endp, base);
152 }
153 EXPORT_SYMBOL(simple_strtoll);
154 
155 static noinline_for_stack
156 int skip_atoi(const char **s)
157 {
158 	int i = 0;
159 
160 	do {
161 		i = i*10 + *((*s)++) - '0';
162 	} while (isdigit(**s));
163 
164 	return i;
165 }
166 
167 /*
168  * Decimal conversion is by far the most typical, and is used for
169  * /proc and /sys data. This directly impacts e.g. top performance
170  * with many processes running. We optimize it for speed by emitting
171  * two characters at a time, using a 200 byte lookup table. This
172  * roughly halves the number of multiplications compared to computing
173  * the digits one at a time. Implementation strongly inspired by the
174  * previous version, which in turn used ideas described at
175  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
176  * from the author, Douglas W. Jones).
177  *
178  * It turns out there is precisely one 26 bit fixed-point
179  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
180  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
181  * range happens to be somewhat larger (x <= 1073741898), but that's
182  * irrelevant for our purpose.
183  *
184  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
185  * need a 32x32->64 bit multiply, so we simply use the same constant.
186  *
187  * For dividing a number in the range [100, 10^4-1] by 100, there are
188  * several options. The simplest is (x * 0x147b) >> 19, which is valid
189  * for all x <= 43698.
190  */
191 
192 static const u16 decpair[100] = {
193 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
194 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
195 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
196 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
197 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
198 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
199 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
200 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
201 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
202 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
203 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
204 #undef _
205 };
206 
207 /*
208  * This will print a single '0' even if r == 0, since we would
209  * immediately jump to out_r where two 0s would be written but only
210  * one of them accounted for in buf. This is needed by ip4_string
211  * below. All other callers pass a non-zero value of r.
212 */
213 static noinline_for_stack
214 char *put_dec_trunc8(char *buf, unsigned r)
215 {
216 	unsigned q;
217 
218 	/* 1 <= r < 10^8 */
219 	if (r < 100)
220 		goto out_r;
221 
222 	/* 100 <= r < 10^8 */
223 	q = (r * (u64)0x28f5c29) >> 32;
224 	*((u16 *)buf) = decpair[r - 100*q];
225 	buf += 2;
226 
227 	/* 1 <= q < 10^6 */
228 	if (q < 100)
229 		goto out_q;
230 
231 	/*  100 <= q < 10^6 */
232 	r = (q * (u64)0x28f5c29) >> 32;
233 	*((u16 *)buf) = decpair[q - 100*r];
234 	buf += 2;
235 
236 	/* 1 <= r < 10^4 */
237 	if (r < 100)
238 		goto out_r;
239 
240 	/* 100 <= r < 10^4 */
241 	q = (r * 0x147b) >> 19;
242 	*((u16 *)buf) = decpair[r - 100*q];
243 	buf += 2;
244 out_q:
245 	/* 1 <= q < 100 */
246 	r = q;
247 out_r:
248 	/* 1 <= r < 100 */
249 	*((u16 *)buf) = decpair[r];
250 	buf += r < 10 ? 1 : 2;
251 	return buf;
252 }
253 
254 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
255 static noinline_for_stack
256 char *put_dec_full8(char *buf, unsigned r)
257 {
258 	unsigned q;
259 
260 	/* 0 <= r < 10^8 */
261 	q = (r * (u64)0x28f5c29) >> 32;
262 	*((u16 *)buf) = decpair[r - 100*q];
263 	buf += 2;
264 
265 	/* 0 <= q < 10^6 */
266 	r = (q * (u64)0x28f5c29) >> 32;
267 	*((u16 *)buf) = decpair[q - 100*r];
268 	buf += 2;
269 
270 	/* 0 <= r < 10^4 */
271 	q = (r * 0x147b) >> 19;
272 	*((u16 *)buf) = decpair[r - 100*q];
273 	buf += 2;
274 
275 	/* 0 <= q < 100 */
276 	*((u16 *)buf) = decpair[q];
277 	buf += 2;
278 	return buf;
279 }
280 
281 static noinline_for_stack
282 char *put_dec(char *buf, unsigned long long n)
283 {
284 	if (n >= 100*1000*1000)
285 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
286 	/* 1 <= n <= 1.6e11 */
287 	if (n >= 100*1000*1000)
288 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
289 	/* 1 <= n < 1e8 */
290 	return put_dec_trunc8(buf, n);
291 }
292 
293 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
294 
295 static void
296 put_dec_full4(char *buf, unsigned r)
297 {
298 	unsigned q;
299 
300 	/* 0 <= r < 10^4 */
301 	q = (r * 0x147b) >> 19;
302 	*((u16 *)buf) = decpair[r - 100*q];
303 	buf += 2;
304 	/* 0 <= q < 100 */
305 	*((u16 *)buf) = decpair[q];
306 }
307 
308 /*
309  * Call put_dec_full4 on x % 10000, return x / 10000.
310  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
311  * holds for all x < 1,128,869,999.  The largest value this
312  * helper will ever be asked to convert is 1,125,520,955.
313  * (second call in the put_dec code, assuming n is all-ones).
314  */
315 static noinline_for_stack
316 unsigned put_dec_helper4(char *buf, unsigned x)
317 {
318         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
319 
320         put_dec_full4(buf, x - q * 10000);
321         return q;
322 }
323 
324 /* Based on code by Douglas W. Jones found at
325  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
326  * (with permission from the author).
327  * Performs no 64-bit division and hence should be fast on 32-bit machines.
328  */
329 static
330 char *put_dec(char *buf, unsigned long long n)
331 {
332 	uint32_t d3, d2, d1, q, h;
333 
334 	if (n < 100*1000*1000)
335 		return put_dec_trunc8(buf, n);
336 
337 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
338 	h   = (n >> 32);
339 	d2  = (h      ) & 0xffff;
340 	d3  = (h >> 16); /* implicit "& 0xffff" */
341 
342 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
343 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
344 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
345 	q = put_dec_helper4(buf, q);
346 
347 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
348 	q = put_dec_helper4(buf+4, q);
349 
350 	q += 4749 * d3 + 42 * d2;
351 	q = put_dec_helper4(buf+8, q);
352 
353 	q += 281 * d3;
354 	buf += 12;
355 	if (q)
356 		buf = put_dec_trunc8(buf, q);
357 	else while (buf[-1] == '0')
358 		--buf;
359 
360 	return buf;
361 }
362 
363 #endif
364 
365 /*
366  * Convert passed number to decimal string.
367  * Returns the length of string.  On buffer overflow, returns 0.
368  *
369  * If speed is not important, use snprintf(). It's easy to read the code.
370  */
371 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
372 {
373 	/* put_dec requires 2-byte alignment of the buffer. */
374 	char tmp[sizeof(num) * 3] __aligned(2);
375 	int idx, len;
376 
377 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
378 	if (num <= 9) {
379 		tmp[0] = '0' + num;
380 		len = 1;
381 	} else {
382 		len = put_dec(tmp, num) - tmp;
383 	}
384 
385 	if (len > size || width > size)
386 		return 0;
387 
388 	if (width > len) {
389 		width = width - len;
390 		for (idx = 0; idx < width; idx++)
391 			buf[idx] = ' ';
392 	} else {
393 		width = 0;
394 	}
395 
396 	for (idx = 0; idx < len; ++idx)
397 		buf[idx + width] = tmp[len - idx - 1];
398 
399 	return len + width;
400 }
401 
402 #define SIGN	1		/* unsigned/signed, must be 1 */
403 #define LEFT	2		/* left justified */
404 #define PLUS	4		/* show plus */
405 #define SPACE	8		/* space if plus */
406 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
407 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
408 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
409 
410 static_assert(SIGN == 1);
411 static_assert(ZEROPAD == ('0' - ' '));
412 static_assert(SMALL == ('a' ^ 'A'));
413 
414 enum format_type {
415 	FORMAT_TYPE_NONE, /* Just a string part */
416 	FORMAT_TYPE_WIDTH,
417 	FORMAT_TYPE_PRECISION,
418 	FORMAT_TYPE_CHAR,
419 	FORMAT_TYPE_STR,
420 	FORMAT_TYPE_PTR,
421 	FORMAT_TYPE_PERCENT_CHAR,
422 	FORMAT_TYPE_INVALID,
423 	FORMAT_TYPE_LONG_LONG,
424 	FORMAT_TYPE_ULONG,
425 	FORMAT_TYPE_LONG,
426 	FORMAT_TYPE_UBYTE,
427 	FORMAT_TYPE_BYTE,
428 	FORMAT_TYPE_USHORT,
429 	FORMAT_TYPE_SHORT,
430 	FORMAT_TYPE_UINT,
431 	FORMAT_TYPE_INT,
432 	FORMAT_TYPE_SIZE_T,
433 	FORMAT_TYPE_PTRDIFF
434 };
435 
436 struct printf_spec {
437 	unsigned int	type:8;		/* format_type enum */
438 	signed int	field_width:24;	/* width of output field */
439 	unsigned int	flags:8;	/* flags to number() */
440 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
441 	signed int	precision:16;	/* # of digits/chars */
442 } __packed;
443 static_assert(sizeof(struct printf_spec) == 8);
444 
445 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
446 #define PRECISION_MAX ((1 << 15) - 1)
447 
448 static noinline_for_stack
449 char *number(char *buf, char *end, unsigned long long num,
450 	     struct printf_spec spec)
451 {
452 	/* put_dec requires 2-byte alignment of the buffer. */
453 	char tmp[3 * sizeof(num)] __aligned(2);
454 	char sign;
455 	char locase;
456 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
457 	int i;
458 	bool is_zero = num == 0LL;
459 	int field_width = spec.field_width;
460 	int precision = spec.precision;
461 
462 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
463 	 * produces same digits or (maybe lowercased) letters */
464 	locase = (spec.flags & SMALL);
465 	if (spec.flags & LEFT)
466 		spec.flags &= ~ZEROPAD;
467 	sign = 0;
468 	if (spec.flags & SIGN) {
469 		if ((signed long long)num < 0) {
470 			sign = '-';
471 			num = -(signed long long)num;
472 			field_width--;
473 		} else if (spec.flags & PLUS) {
474 			sign = '+';
475 			field_width--;
476 		} else if (spec.flags & SPACE) {
477 			sign = ' ';
478 			field_width--;
479 		}
480 	}
481 	if (need_pfx) {
482 		if (spec.base == 16)
483 			field_width -= 2;
484 		else if (!is_zero)
485 			field_width--;
486 	}
487 
488 	/* generate full string in tmp[], in reverse order */
489 	i = 0;
490 	if (num < spec.base)
491 		tmp[i++] = hex_asc_upper[num] | locase;
492 	else if (spec.base != 10) { /* 8 or 16 */
493 		int mask = spec.base - 1;
494 		int shift = 3;
495 
496 		if (spec.base == 16)
497 			shift = 4;
498 		do {
499 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
500 			num >>= shift;
501 		} while (num);
502 	} else { /* base 10 */
503 		i = put_dec(tmp, num) - tmp;
504 	}
505 
506 	/* printing 100 using %2d gives "100", not "00" */
507 	if (i > precision)
508 		precision = i;
509 	/* leading space padding */
510 	field_width -= precision;
511 	if (!(spec.flags & (ZEROPAD | LEFT))) {
512 		while (--field_width >= 0) {
513 			if (buf < end)
514 				*buf = ' ';
515 			++buf;
516 		}
517 	}
518 	/* sign */
519 	if (sign) {
520 		if (buf < end)
521 			*buf = sign;
522 		++buf;
523 	}
524 	/* "0x" / "0" prefix */
525 	if (need_pfx) {
526 		if (spec.base == 16 || !is_zero) {
527 			if (buf < end)
528 				*buf = '0';
529 			++buf;
530 		}
531 		if (spec.base == 16) {
532 			if (buf < end)
533 				*buf = ('X' | locase);
534 			++buf;
535 		}
536 	}
537 	/* zero or space padding */
538 	if (!(spec.flags & LEFT)) {
539 		char c = ' ' + (spec.flags & ZEROPAD);
540 
541 		while (--field_width >= 0) {
542 			if (buf < end)
543 				*buf = c;
544 			++buf;
545 		}
546 	}
547 	/* hmm even more zero padding? */
548 	while (i <= --precision) {
549 		if (buf < end)
550 			*buf = '0';
551 		++buf;
552 	}
553 	/* actual digits of result */
554 	while (--i >= 0) {
555 		if (buf < end)
556 			*buf = tmp[i];
557 		++buf;
558 	}
559 	/* trailing space padding */
560 	while (--field_width >= 0) {
561 		if (buf < end)
562 			*buf = ' ';
563 		++buf;
564 	}
565 
566 	return buf;
567 }
568 
569 static noinline_for_stack
570 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
571 {
572 	struct printf_spec spec;
573 
574 	spec.type = FORMAT_TYPE_PTR;
575 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
576 	spec.flags = SPECIAL | SMALL | ZEROPAD;
577 	spec.base = 16;
578 	spec.precision = -1;
579 
580 	return number(buf, end, num, spec);
581 }
582 
583 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
584 {
585 	size_t size;
586 	if (buf >= end)	/* nowhere to put anything */
587 		return;
588 	size = end - buf;
589 	if (size <= spaces) {
590 		memset(buf, ' ', size);
591 		return;
592 	}
593 	if (len) {
594 		if (len > size - spaces)
595 			len = size - spaces;
596 		memmove(buf + spaces, buf, len);
597 	}
598 	memset(buf, ' ', spaces);
599 }
600 
601 /*
602  * Handle field width padding for a string.
603  * @buf: current buffer position
604  * @n: length of string
605  * @end: end of output buffer
606  * @spec: for field width and flags
607  * Returns: new buffer position after padding.
608  */
609 static noinline_for_stack
610 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
611 {
612 	unsigned spaces;
613 
614 	if (likely(n >= spec.field_width))
615 		return buf;
616 	/* we want to pad the sucker */
617 	spaces = spec.field_width - n;
618 	if (!(spec.flags & LEFT)) {
619 		move_right(buf - n, end, n, spaces);
620 		return buf + spaces;
621 	}
622 	while (spaces--) {
623 		if (buf < end)
624 			*buf = ' ';
625 		++buf;
626 	}
627 	return buf;
628 }
629 
630 /* Handle string from a well known address. */
631 static char *string_nocheck(char *buf, char *end, const char *s,
632 			    struct printf_spec spec)
633 {
634 	int len = 0;
635 	int lim = spec.precision;
636 
637 	while (lim--) {
638 		char c = *s++;
639 		if (!c)
640 			break;
641 		if (buf < end)
642 			*buf = c;
643 		++buf;
644 		++len;
645 	}
646 	return widen_string(buf, len, end, spec);
647 }
648 
649 static char *err_ptr(char *buf, char *end, void *ptr,
650 		     struct printf_spec spec)
651 {
652 	int err = PTR_ERR(ptr);
653 	const char *sym = errname(err);
654 
655 	if (sym)
656 		return string_nocheck(buf, end, sym, spec);
657 
658 	/*
659 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
660 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
661 	 * printing it as its decimal representation.
662 	 */
663 	spec.flags |= SIGN;
664 	spec.base = 10;
665 	return number(buf, end, err, spec);
666 }
667 
668 /* Be careful: error messages must fit into the given buffer. */
669 static char *error_string(char *buf, char *end, const char *s,
670 			  struct printf_spec spec)
671 {
672 	/*
673 	 * Hard limit to avoid a completely insane messages. It actually
674 	 * works pretty well because most error messages are in
675 	 * the many pointer format modifiers.
676 	 */
677 	if (spec.precision == -1)
678 		spec.precision = 2 * sizeof(void *);
679 
680 	return string_nocheck(buf, end, s, spec);
681 }
682 
683 /*
684  * Do not call any complex external code here. Nested printk()/vsprintf()
685  * might cause infinite loops. Failures might break printk() and would
686  * be hard to debug.
687  */
688 static const char *check_pointer_msg(const void *ptr)
689 {
690 	if (!ptr)
691 		return "(null)";
692 
693 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
694 		return "(efault)";
695 
696 	return NULL;
697 }
698 
699 static int check_pointer(char **buf, char *end, const void *ptr,
700 			 struct printf_spec spec)
701 {
702 	const char *err_msg;
703 
704 	err_msg = check_pointer_msg(ptr);
705 	if (err_msg) {
706 		*buf = error_string(*buf, end, err_msg, spec);
707 		return -EFAULT;
708 	}
709 
710 	return 0;
711 }
712 
713 static noinline_for_stack
714 char *string(char *buf, char *end, const char *s,
715 	     struct printf_spec spec)
716 {
717 	if (check_pointer(&buf, end, s, spec))
718 		return buf;
719 
720 	return string_nocheck(buf, end, s, spec);
721 }
722 
723 static char *pointer_string(char *buf, char *end,
724 			    const void *ptr,
725 			    struct printf_spec spec)
726 {
727 	spec.base = 16;
728 	spec.flags |= SMALL;
729 	if (spec.field_width == -1) {
730 		spec.field_width = 2 * sizeof(ptr);
731 		spec.flags |= ZEROPAD;
732 	}
733 
734 	return number(buf, end, (unsigned long int)ptr, spec);
735 }
736 
737 /* Make pointers available for printing early in the boot sequence. */
738 static int debug_boot_weak_hash __ro_after_init;
739 
740 static int __init debug_boot_weak_hash_enable(char *str)
741 {
742 	debug_boot_weak_hash = 1;
743 	pr_info("debug_boot_weak_hash enabled\n");
744 	return 0;
745 }
746 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
747 
748 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
749 static siphash_key_t ptr_key __read_mostly;
750 
751 static void enable_ptr_key_workfn(struct work_struct *work)
752 {
753 	get_random_bytes(&ptr_key, sizeof(ptr_key));
754 	/* Needs to run from preemptible context */
755 	static_branch_disable(&not_filled_random_ptr_key);
756 }
757 
758 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
759 
760 static void fill_random_ptr_key(struct random_ready_callback *unused)
761 {
762 	/* This may be in an interrupt handler. */
763 	queue_work(system_unbound_wq, &enable_ptr_key_work);
764 }
765 
766 static struct random_ready_callback random_ready = {
767 	.func = fill_random_ptr_key
768 };
769 
770 static int __init initialize_ptr_random(void)
771 {
772 	int key_size = sizeof(ptr_key);
773 	int ret;
774 
775 	/* Use hw RNG if available. */
776 	if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
777 		static_branch_disable(&not_filled_random_ptr_key);
778 		return 0;
779 	}
780 
781 	ret = add_random_ready_callback(&random_ready);
782 	if (!ret) {
783 		return 0;
784 	} else if (ret == -EALREADY) {
785 		/* This is in preemptible context */
786 		enable_ptr_key_workfn(&enable_ptr_key_work);
787 		return 0;
788 	}
789 
790 	return ret;
791 }
792 early_initcall(initialize_ptr_random);
793 
794 /* Maps a pointer to a 32 bit unique identifier. */
795 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
796 {
797 	unsigned long hashval;
798 
799 	if (static_branch_unlikely(&not_filled_random_ptr_key))
800 		return -EAGAIN;
801 
802 #ifdef CONFIG_64BIT
803 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
804 	/*
805 	 * Mask off the first 32 bits, this makes explicit that we have
806 	 * modified the address (and 32 bits is plenty for a unique ID).
807 	 */
808 	hashval = hashval & 0xffffffff;
809 #else
810 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
811 #endif
812 	*hashval_out = hashval;
813 	return 0;
814 }
815 
816 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
817 {
818 	return __ptr_to_hashval(ptr, hashval_out);
819 }
820 
821 static char *ptr_to_id(char *buf, char *end, const void *ptr,
822 		       struct printf_spec spec)
823 {
824 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
825 	unsigned long hashval;
826 	int ret;
827 
828 	/*
829 	 * Print the real pointer value for NULL and error pointers,
830 	 * as they are not actual addresses.
831 	 */
832 	if (IS_ERR_OR_NULL(ptr))
833 		return pointer_string(buf, end, ptr, spec);
834 
835 	/* When debugging early boot use non-cryptographically secure hash. */
836 	if (unlikely(debug_boot_weak_hash)) {
837 		hashval = hash_long((unsigned long)ptr, 32);
838 		return pointer_string(buf, end, (const void *)hashval, spec);
839 	}
840 
841 	ret = __ptr_to_hashval(ptr, &hashval);
842 	if (ret) {
843 		spec.field_width = 2 * sizeof(ptr);
844 		/* string length must be less than default_width */
845 		return error_string(buf, end, str, spec);
846 	}
847 
848 	return pointer_string(buf, end, (const void *)hashval, spec);
849 }
850 
851 int kptr_restrict __read_mostly;
852 
853 static noinline_for_stack
854 char *restricted_pointer(char *buf, char *end, const void *ptr,
855 			 struct printf_spec spec)
856 {
857 	switch (kptr_restrict) {
858 	case 0:
859 		/* Handle as %p, hash and do _not_ leak addresses. */
860 		return ptr_to_id(buf, end, ptr, spec);
861 	case 1: {
862 		const struct cred *cred;
863 
864 		/*
865 		 * kptr_restrict==1 cannot be used in IRQ context
866 		 * because its test for CAP_SYSLOG would be meaningless.
867 		 */
868 		if (in_irq() || in_serving_softirq() || in_nmi()) {
869 			if (spec.field_width == -1)
870 				spec.field_width = 2 * sizeof(ptr);
871 			return error_string(buf, end, "pK-error", spec);
872 		}
873 
874 		/*
875 		 * Only print the real pointer value if the current
876 		 * process has CAP_SYSLOG and is running with the
877 		 * same credentials it started with. This is because
878 		 * access to files is checked at open() time, but %pK
879 		 * checks permission at read() time. We don't want to
880 		 * leak pointer values if a binary opens a file using
881 		 * %pK and then elevates privileges before reading it.
882 		 */
883 		cred = current_cred();
884 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
885 		    !uid_eq(cred->euid, cred->uid) ||
886 		    !gid_eq(cred->egid, cred->gid))
887 			ptr = NULL;
888 		break;
889 	}
890 	case 2:
891 	default:
892 		/* Always print 0's for %pK */
893 		ptr = NULL;
894 		break;
895 	}
896 
897 	return pointer_string(buf, end, ptr, spec);
898 }
899 
900 static noinline_for_stack
901 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
902 		  const char *fmt)
903 {
904 	const char *array[4], *s;
905 	const struct dentry *p;
906 	int depth;
907 	int i, n;
908 
909 	switch (fmt[1]) {
910 		case '2': case '3': case '4':
911 			depth = fmt[1] - '0';
912 			break;
913 		default:
914 			depth = 1;
915 	}
916 
917 	rcu_read_lock();
918 	for (i = 0; i < depth; i++, d = p) {
919 		if (check_pointer(&buf, end, d, spec)) {
920 			rcu_read_unlock();
921 			return buf;
922 		}
923 
924 		p = READ_ONCE(d->d_parent);
925 		array[i] = READ_ONCE(d->d_name.name);
926 		if (p == d) {
927 			if (i)
928 				array[i] = "";
929 			i++;
930 			break;
931 		}
932 	}
933 	s = array[--i];
934 	for (n = 0; n != spec.precision; n++, buf++) {
935 		char c = *s++;
936 		if (!c) {
937 			if (!i)
938 				break;
939 			c = '/';
940 			s = array[--i];
941 		}
942 		if (buf < end)
943 			*buf = c;
944 	}
945 	rcu_read_unlock();
946 	return widen_string(buf, n, end, spec);
947 }
948 
949 static noinline_for_stack
950 char *file_dentry_name(char *buf, char *end, const struct file *f,
951 			struct printf_spec spec, const char *fmt)
952 {
953 	if (check_pointer(&buf, end, f, spec))
954 		return buf;
955 
956 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
957 }
958 #ifdef CONFIG_BLOCK
959 static noinline_for_stack
960 char *bdev_name(char *buf, char *end, struct block_device *bdev,
961 		struct printf_spec spec, const char *fmt)
962 {
963 	struct gendisk *hd;
964 
965 	if (check_pointer(&buf, end, bdev, spec))
966 		return buf;
967 
968 	hd = bdev->bd_disk;
969 	buf = string(buf, end, hd->disk_name, spec);
970 	if (bdev->bd_partno) {
971 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
972 			if (buf < end)
973 				*buf = 'p';
974 			buf++;
975 		}
976 		buf = number(buf, end, bdev->bd_partno, spec);
977 	}
978 	return buf;
979 }
980 #endif
981 
982 static noinline_for_stack
983 char *symbol_string(char *buf, char *end, void *ptr,
984 		    struct printf_spec spec, const char *fmt)
985 {
986 	unsigned long value;
987 #ifdef CONFIG_KALLSYMS
988 	char sym[KSYM_SYMBOL_LEN];
989 #endif
990 
991 	if (fmt[1] == 'R')
992 		ptr = __builtin_extract_return_addr(ptr);
993 	value = (unsigned long)ptr;
994 
995 #ifdef CONFIG_KALLSYMS
996 	if (*fmt == 'B' && fmt[1] == 'b')
997 		sprint_backtrace_build_id(sym, value);
998 	else if (*fmt == 'B')
999 		sprint_backtrace(sym, value);
1000 	else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1001 		sprint_symbol_build_id(sym, value);
1002 	else if (*fmt != 's')
1003 		sprint_symbol(sym, value);
1004 	else
1005 		sprint_symbol_no_offset(sym, value);
1006 
1007 	return string_nocheck(buf, end, sym, spec);
1008 #else
1009 	return special_hex_number(buf, end, value, sizeof(void *));
1010 #endif
1011 }
1012 
1013 static const struct printf_spec default_str_spec = {
1014 	.field_width = -1,
1015 	.precision = -1,
1016 };
1017 
1018 static const struct printf_spec default_flag_spec = {
1019 	.base = 16,
1020 	.precision = -1,
1021 	.flags = SPECIAL | SMALL,
1022 };
1023 
1024 static const struct printf_spec default_dec_spec = {
1025 	.base = 10,
1026 	.precision = -1,
1027 };
1028 
1029 static const struct printf_spec default_dec02_spec = {
1030 	.base = 10,
1031 	.field_width = 2,
1032 	.precision = -1,
1033 	.flags = ZEROPAD,
1034 };
1035 
1036 static const struct printf_spec default_dec04_spec = {
1037 	.base = 10,
1038 	.field_width = 4,
1039 	.precision = -1,
1040 	.flags = ZEROPAD,
1041 };
1042 
1043 static noinline_for_stack
1044 char *resource_string(char *buf, char *end, struct resource *res,
1045 		      struct printf_spec spec, const char *fmt)
1046 {
1047 #ifndef IO_RSRC_PRINTK_SIZE
1048 #define IO_RSRC_PRINTK_SIZE	6
1049 #endif
1050 
1051 #ifndef MEM_RSRC_PRINTK_SIZE
1052 #define MEM_RSRC_PRINTK_SIZE	10
1053 #endif
1054 	static const struct printf_spec io_spec = {
1055 		.base = 16,
1056 		.field_width = IO_RSRC_PRINTK_SIZE,
1057 		.precision = -1,
1058 		.flags = SPECIAL | SMALL | ZEROPAD,
1059 	};
1060 	static const struct printf_spec mem_spec = {
1061 		.base = 16,
1062 		.field_width = MEM_RSRC_PRINTK_SIZE,
1063 		.precision = -1,
1064 		.flags = SPECIAL | SMALL | ZEROPAD,
1065 	};
1066 	static const struct printf_spec bus_spec = {
1067 		.base = 16,
1068 		.field_width = 2,
1069 		.precision = -1,
1070 		.flags = SMALL | ZEROPAD,
1071 	};
1072 	static const struct printf_spec str_spec = {
1073 		.field_width = -1,
1074 		.precision = 10,
1075 		.flags = LEFT,
1076 	};
1077 
1078 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1079 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1080 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1081 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1082 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1083 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1084 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1085 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1086 
1087 	char *p = sym, *pend = sym + sizeof(sym);
1088 	int decode = (fmt[0] == 'R') ? 1 : 0;
1089 	const struct printf_spec *specp;
1090 
1091 	if (check_pointer(&buf, end, res, spec))
1092 		return buf;
1093 
1094 	*p++ = '[';
1095 	if (res->flags & IORESOURCE_IO) {
1096 		p = string_nocheck(p, pend, "io  ", str_spec);
1097 		specp = &io_spec;
1098 	} else if (res->flags & IORESOURCE_MEM) {
1099 		p = string_nocheck(p, pend, "mem ", str_spec);
1100 		specp = &mem_spec;
1101 	} else if (res->flags & IORESOURCE_IRQ) {
1102 		p = string_nocheck(p, pend, "irq ", str_spec);
1103 		specp = &default_dec_spec;
1104 	} else if (res->flags & IORESOURCE_DMA) {
1105 		p = string_nocheck(p, pend, "dma ", str_spec);
1106 		specp = &default_dec_spec;
1107 	} else if (res->flags & IORESOURCE_BUS) {
1108 		p = string_nocheck(p, pend, "bus ", str_spec);
1109 		specp = &bus_spec;
1110 	} else {
1111 		p = string_nocheck(p, pend, "??? ", str_spec);
1112 		specp = &mem_spec;
1113 		decode = 0;
1114 	}
1115 	if (decode && res->flags & IORESOURCE_UNSET) {
1116 		p = string_nocheck(p, pend, "size ", str_spec);
1117 		p = number(p, pend, resource_size(res), *specp);
1118 	} else {
1119 		p = number(p, pend, res->start, *specp);
1120 		if (res->start != res->end) {
1121 			*p++ = '-';
1122 			p = number(p, pend, res->end, *specp);
1123 		}
1124 	}
1125 	if (decode) {
1126 		if (res->flags & IORESOURCE_MEM_64)
1127 			p = string_nocheck(p, pend, " 64bit", str_spec);
1128 		if (res->flags & IORESOURCE_PREFETCH)
1129 			p = string_nocheck(p, pend, " pref", str_spec);
1130 		if (res->flags & IORESOURCE_WINDOW)
1131 			p = string_nocheck(p, pend, " window", str_spec);
1132 		if (res->flags & IORESOURCE_DISABLED)
1133 			p = string_nocheck(p, pend, " disabled", str_spec);
1134 	} else {
1135 		p = string_nocheck(p, pend, " flags ", str_spec);
1136 		p = number(p, pend, res->flags, default_flag_spec);
1137 	}
1138 	*p++ = ']';
1139 	*p = '\0';
1140 
1141 	return string_nocheck(buf, end, sym, spec);
1142 }
1143 
1144 static noinline_for_stack
1145 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1146 		 const char *fmt)
1147 {
1148 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1149 				   negative value, fallback to the default */
1150 	char separator;
1151 
1152 	if (spec.field_width == 0)
1153 		/* nothing to print */
1154 		return buf;
1155 
1156 	if (check_pointer(&buf, end, addr, spec))
1157 		return buf;
1158 
1159 	switch (fmt[1]) {
1160 	case 'C':
1161 		separator = ':';
1162 		break;
1163 	case 'D':
1164 		separator = '-';
1165 		break;
1166 	case 'N':
1167 		separator = 0;
1168 		break;
1169 	default:
1170 		separator = ' ';
1171 		break;
1172 	}
1173 
1174 	if (spec.field_width > 0)
1175 		len = min_t(int, spec.field_width, 64);
1176 
1177 	for (i = 0; i < len; ++i) {
1178 		if (buf < end)
1179 			*buf = hex_asc_hi(addr[i]);
1180 		++buf;
1181 		if (buf < end)
1182 			*buf = hex_asc_lo(addr[i]);
1183 		++buf;
1184 
1185 		if (separator && i != len - 1) {
1186 			if (buf < end)
1187 				*buf = separator;
1188 			++buf;
1189 		}
1190 	}
1191 
1192 	return buf;
1193 }
1194 
1195 static noinline_for_stack
1196 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1197 		    struct printf_spec spec, const char *fmt)
1198 {
1199 	const int CHUNKSZ = 32;
1200 	int nr_bits = max_t(int, spec.field_width, 0);
1201 	int i, chunksz;
1202 	bool first = true;
1203 
1204 	if (check_pointer(&buf, end, bitmap, spec))
1205 		return buf;
1206 
1207 	/* reused to print numbers */
1208 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1209 
1210 	chunksz = nr_bits & (CHUNKSZ - 1);
1211 	if (chunksz == 0)
1212 		chunksz = CHUNKSZ;
1213 
1214 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1215 	for (; i >= 0; i -= CHUNKSZ) {
1216 		u32 chunkmask, val;
1217 		int word, bit;
1218 
1219 		chunkmask = ((1ULL << chunksz) - 1);
1220 		word = i / BITS_PER_LONG;
1221 		bit = i % BITS_PER_LONG;
1222 		val = (bitmap[word] >> bit) & chunkmask;
1223 
1224 		if (!first) {
1225 			if (buf < end)
1226 				*buf = ',';
1227 			buf++;
1228 		}
1229 		first = false;
1230 
1231 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1232 		buf = number(buf, end, val, spec);
1233 
1234 		chunksz = CHUNKSZ;
1235 	}
1236 	return buf;
1237 }
1238 
1239 static noinline_for_stack
1240 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1241 			 struct printf_spec spec, const char *fmt)
1242 {
1243 	int nr_bits = max_t(int, spec.field_width, 0);
1244 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
1245 	int cur, rbot, rtop;
1246 	bool first = true;
1247 
1248 	if (check_pointer(&buf, end, bitmap, spec))
1249 		return buf;
1250 
1251 	rbot = cur = find_first_bit(bitmap, nr_bits);
1252 	while (cur < nr_bits) {
1253 		rtop = cur;
1254 		cur = find_next_bit(bitmap, nr_bits, cur + 1);
1255 		if (cur < nr_bits && cur <= rtop + 1)
1256 			continue;
1257 
1258 		if (!first) {
1259 			if (buf < end)
1260 				*buf = ',';
1261 			buf++;
1262 		}
1263 		first = false;
1264 
1265 		buf = number(buf, end, rbot, default_dec_spec);
1266 		if (rbot < rtop) {
1267 			if (buf < end)
1268 				*buf = '-';
1269 			buf++;
1270 
1271 			buf = number(buf, end, rtop, default_dec_spec);
1272 		}
1273 
1274 		rbot = cur;
1275 	}
1276 	return buf;
1277 }
1278 
1279 static noinline_for_stack
1280 char *mac_address_string(char *buf, char *end, u8 *addr,
1281 			 struct printf_spec spec, const char *fmt)
1282 {
1283 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1284 	char *p = mac_addr;
1285 	int i;
1286 	char separator;
1287 	bool reversed = false;
1288 
1289 	if (check_pointer(&buf, end, addr, spec))
1290 		return buf;
1291 
1292 	switch (fmt[1]) {
1293 	case 'F':
1294 		separator = '-';
1295 		break;
1296 
1297 	case 'R':
1298 		reversed = true;
1299 		fallthrough;
1300 
1301 	default:
1302 		separator = ':';
1303 		break;
1304 	}
1305 
1306 	for (i = 0; i < 6; i++) {
1307 		if (reversed)
1308 			p = hex_byte_pack(p, addr[5 - i]);
1309 		else
1310 			p = hex_byte_pack(p, addr[i]);
1311 
1312 		if (fmt[0] == 'M' && i != 5)
1313 			*p++ = separator;
1314 	}
1315 	*p = '\0';
1316 
1317 	return string_nocheck(buf, end, mac_addr, spec);
1318 }
1319 
1320 static noinline_for_stack
1321 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1322 {
1323 	int i;
1324 	bool leading_zeros = (fmt[0] == 'i');
1325 	int index;
1326 	int step;
1327 
1328 	switch (fmt[2]) {
1329 	case 'h':
1330 #ifdef __BIG_ENDIAN
1331 		index = 0;
1332 		step = 1;
1333 #else
1334 		index = 3;
1335 		step = -1;
1336 #endif
1337 		break;
1338 	case 'l':
1339 		index = 3;
1340 		step = -1;
1341 		break;
1342 	case 'n':
1343 	case 'b':
1344 	default:
1345 		index = 0;
1346 		step = 1;
1347 		break;
1348 	}
1349 	for (i = 0; i < 4; i++) {
1350 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1351 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1352 		if (leading_zeros) {
1353 			if (digits < 3)
1354 				*p++ = '0';
1355 			if (digits < 2)
1356 				*p++ = '0';
1357 		}
1358 		/* reverse the digits in the quad */
1359 		while (digits--)
1360 			*p++ = temp[digits];
1361 		if (i < 3)
1362 			*p++ = '.';
1363 		index += step;
1364 	}
1365 	*p = '\0';
1366 
1367 	return p;
1368 }
1369 
1370 static noinline_for_stack
1371 char *ip6_compressed_string(char *p, const char *addr)
1372 {
1373 	int i, j, range;
1374 	unsigned char zerolength[8];
1375 	int longest = 1;
1376 	int colonpos = -1;
1377 	u16 word;
1378 	u8 hi, lo;
1379 	bool needcolon = false;
1380 	bool useIPv4;
1381 	struct in6_addr in6;
1382 
1383 	memcpy(&in6, addr, sizeof(struct in6_addr));
1384 
1385 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1386 
1387 	memset(zerolength, 0, sizeof(zerolength));
1388 
1389 	if (useIPv4)
1390 		range = 6;
1391 	else
1392 		range = 8;
1393 
1394 	/* find position of longest 0 run */
1395 	for (i = 0; i < range; i++) {
1396 		for (j = i; j < range; j++) {
1397 			if (in6.s6_addr16[j] != 0)
1398 				break;
1399 			zerolength[i]++;
1400 		}
1401 	}
1402 	for (i = 0; i < range; i++) {
1403 		if (zerolength[i] > longest) {
1404 			longest = zerolength[i];
1405 			colonpos = i;
1406 		}
1407 	}
1408 	if (longest == 1)		/* don't compress a single 0 */
1409 		colonpos = -1;
1410 
1411 	/* emit address */
1412 	for (i = 0; i < range; i++) {
1413 		if (i == colonpos) {
1414 			if (needcolon || i == 0)
1415 				*p++ = ':';
1416 			*p++ = ':';
1417 			needcolon = false;
1418 			i += longest - 1;
1419 			continue;
1420 		}
1421 		if (needcolon) {
1422 			*p++ = ':';
1423 			needcolon = false;
1424 		}
1425 		/* hex u16 without leading 0s */
1426 		word = ntohs(in6.s6_addr16[i]);
1427 		hi = word >> 8;
1428 		lo = word & 0xff;
1429 		if (hi) {
1430 			if (hi > 0x0f)
1431 				p = hex_byte_pack(p, hi);
1432 			else
1433 				*p++ = hex_asc_lo(hi);
1434 			p = hex_byte_pack(p, lo);
1435 		}
1436 		else if (lo > 0x0f)
1437 			p = hex_byte_pack(p, lo);
1438 		else
1439 			*p++ = hex_asc_lo(lo);
1440 		needcolon = true;
1441 	}
1442 
1443 	if (useIPv4) {
1444 		if (needcolon)
1445 			*p++ = ':';
1446 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1447 	}
1448 	*p = '\0';
1449 
1450 	return p;
1451 }
1452 
1453 static noinline_for_stack
1454 char *ip6_string(char *p, const char *addr, const char *fmt)
1455 {
1456 	int i;
1457 
1458 	for (i = 0; i < 8; i++) {
1459 		p = hex_byte_pack(p, *addr++);
1460 		p = hex_byte_pack(p, *addr++);
1461 		if (fmt[0] == 'I' && i != 7)
1462 			*p++ = ':';
1463 	}
1464 	*p = '\0';
1465 
1466 	return p;
1467 }
1468 
1469 static noinline_for_stack
1470 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1471 		      struct printf_spec spec, const char *fmt)
1472 {
1473 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1474 
1475 	if (fmt[0] == 'I' && fmt[2] == 'c')
1476 		ip6_compressed_string(ip6_addr, addr);
1477 	else
1478 		ip6_string(ip6_addr, addr, fmt);
1479 
1480 	return string_nocheck(buf, end, ip6_addr, spec);
1481 }
1482 
1483 static noinline_for_stack
1484 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1485 		      struct printf_spec spec, const char *fmt)
1486 {
1487 	char ip4_addr[sizeof("255.255.255.255")];
1488 
1489 	ip4_string(ip4_addr, addr, fmt);
1490 
1491 	return string_nocheck(buf, end, ip4_addr, spec);
1492 }
1493 
1494 static noinline_for_stack
1495 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1496 			 struct printf_spec spec, const char *fmt)
1497 {
1498 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1499 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1500 		      sizeof(":12345") + sizeof("/123456789") +
1501 		      sizeof("%1234567890")];
1502 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1503 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1504 	char fmt6[2] = { fmt[0], '6' };
1505 	u8 off = 0;
1506 
1507 	fmt++;
1508 	while (isalpha(*++fmt)) {
1509 		switch (*fmt) {
1510 		case 'p':
1511 			have_p = true;
1512 			break;
1513 		case 'f':
1514 			have_f = true;
1515 			break;
1516 		case 's':
1517 			have_s = true;
1518 			break;
1519 		case 'c':
1520 			have_c = true;
1521 			break;
1522 		}
1523 	}
1524 
1525 	if (have_p || have_s || have_f) {
1526 		*p = '[';
1527 		off = 1;
1528 	}
1529 
1530 	if (fmt6[0] == 'I' && have_c)
1531 		p = ip6_compressed_string(ip6_addr + off, addr);
1532 	else
1533 		p = ip6_string(ip6_addr + off, addr, fmt6);
1534 
1535 	if (have_p || have_s || have_f)
1536 		*p++ = ']';
1537 
1538 	if (have_p) {
1539 		*p++ = ':';
1540 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1541 	}
1542 	if (have_f) {
1543 		*p++ = '/';
1544 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1545 					  IPV6_FLOWINFO_MASK), spec);
1546 	}
1547 	if (have_s) {
1548 		*p++ = '%';
1549 		p = number(p, pend, sa->sin6_scope_id, spec);
1550 	}
1551 	*p = '\0';
1552 
1553 	return string_nocheck(buf, end, ip6_addr, spec);
1554 }
1555 
1556 static noinline_for_stack
1557 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1558 			 struct printf_spec spec, const char *fmt)
1559 {
1560 	bool have_p = false;
1561 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1562 	char *pend = ip4_addr + sizeof(ip4_addr);
1563 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1564 	char fmt4[3] = { fmt[0], '4', 0 };
1565 
1566 	fmt++;
1567 	while (isalpha(*++fmt)) {
1568 		switch (*fmt) {
1569 		case 'p':
1570 			have_p = true;
1571 			break;
1572 		case 'h':
1573 		case 'l':
1574 		case 'n':
1575 		case 'b':
1576 			fmt4[2] = *fmt;
1577 			break;
1578 		}
1579 	}
1580 
1581 	p = ip4_string(ip4_addr, addr, fmt4);
1582 	if (have_p) {
1583 		*p++ = ':';
1584 		p = number(p, pend, ntohs(sa->sin_port), spec);
1585 	}
1586 	*p = '\0';
1587 
1588 	return string_nocheck(buf, end, ip4_addr, spec);
1589 }
1590 
1591 static noinline_for_stack
1592 char *ip_addr_string(char *buf, char *end, const void *ptr,
1593 		     struct printf_spec spec, const char *fmt)
1594 {
1595 	char *err_fmt_msg;
1596 
1597 	if (check_pointer(&buf, end, ptr, spec))
1598 		return buf;
1599 
1600 	switch (fmt[1]) {
1601 	case '6':
1602 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1603 	case '4':
1604 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1605 	case 'S': {
1606 		const union {
1607 			struct sockaddr		raw;
1608 			struct sockaddr_in	v4;
1609 			struct sockaddr_in6	v6;
1610 		} *sa = ptr;
1611 
1612 		switch (sa->raw.sa_family) {
1613 		case AF_INET:
1614 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1615 		case AF_INET6:
1616 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1617 		default:
1618 			return error_string(buf, end, "(einval)", spec);
1619 		}}
1620 	}
1621 
1622 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1623 	return error_string(buf, end, err_fmt_msg, spec);
1624 }
1625 
1626 static noinline_for_stack
1627 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1628 		     const char *fmt)
1629 {
1630 	bool found = true;
1631 	int count = 1;
1632 	unsigned int flags = 0;
1633 	int len;
1634 
1635 	if (spec.field_width == 0)
1636 		return buf;				/* nothing to print */
1637 
1638 	if (check_pointer(&buf, end, addr, spec))
1639 		return buf;
1640 
1641 	do {
1642 		switch (fmt[count++]) {
1643 		case 'a':
1644 			flags |= ESCAPE_ANY;
1645 			break;
1646 		case 'c':
1647 			flags |= ESCAPE_SPECIAL;
1648 			break;
1649 		case 'h':
1650 			flags |= ESCAPE_HEX;
1651 			break;
1652 		case 'n':
1653 			flags |= ESCAPE_NULL;
1654 			break;
1655 		case 'o':
1656 			flags |= ESCAPE_OCTAL;
1657 			break;
1658 		case 'p':
1659 			flags |= ESCAPE_NP;
1660 			break;
1661 		case 's':
1662 			flags |= ESCAPE_SPACE;
1663 			break;
1664 		default:
1665 			found = false;
1666 			break;
1667 		}
1668 	} while (found);
1669 
1670 	if (!flags)
1671 		flags = ESCAPE_ANY_NP;
1672 
1673 	len = spec.field_width < 0 ? 1 : spec.field_width;
1674 
1675 	/*
1676 	 * string_escape_mem() writes as many characters as it can to
1677 	 * the given buffer, and returns the total size of the output
1678 	 * had the buffer been big enough.
1679 	 */
1680 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1681 
1682 	return buf;
1683 }
1684 
1685 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1686 		       struct printf_spec spec, const char *fmt)
1687 {
1688 	va_list va;
1689 
1690 	if (check_pointer(&buf, end, va_fmt, spec))
1691 		return buf;
1692 
1693 	va_copy(va, *va_fmt->va);
1694 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1695 	va_end(va);
1696 
1697 	return buf;
1698 }
1699 
1700 static noinline_for_stack
1701 char *uuid_string(char *buf, char *end, const u8 *addr,
1702 		  struct printf_spec spec, const char *fmt)
1703 {
1704 	char uuid[UUID_STRING_LEN + 1];
1705 	char *p = uuid;
1706 	int i;
1707 	const u8 *index = uuid_index;
1708 	bool uc = false;
1709 
1710 	if (check_pointer(&buf, end, addr, spec))
1711 		return buf;
1712 
1713 	switch (*(++fmt)) {
1714 	case 'L':
1715 		uc = true;
1716 		fallthrough;
1717 	case 'l':
1718 		index = guid_index;
1719 		break;
1720 	case 'B':
1721 		uc = true;
1722 		break;
1723 	}
1724 
1725 	for (i = 0; i < 16; i++) {
1726 		if (uc)
1727 			p = hex_byte_pack_upper(p, addr[index[i]]);
1728 		else
1729 			p = hex_byte_pack(p, addr[index[i]]);
1730 		switch (i) {
1731 		case 3:
1732 		case 5:
1733 		case 7:
1734 		case 9:
1735 			*p++ = '-';
1736 			break;
1737 		}
1738 	}
1739 
1740 	*p = 0;
1741 
1742 	return string_nocheck(buf, end, uuid, spec);
1743 }
1744 
1745 static noinline_for_stack
1746 char *netdev_bits(char *buf, char *end, const void *addr,
1747 		  struct printf_spec spec,  const char *fmt)
1748 {
1749 	unsigned long long num;
1750 	int size;
1751 
1752 	if (check_pointer(&buf, end, addr, spec))
1753 		return buf;
1754 
1755 	switch (fmt[1]) {
1756 	case 'F':
1757 		num = *(const netdev_features_t *)addr;
1758 		size = sizeof(netdev_features_t);
1759 		break;
1760 	default:
1761 		return error_string(buf, end, "(%pN?)", spec);
1762 	}
1763 
1764 	return special_hex_number(buf, end, num, size);
1765 }
1766 
1767 static noinline_for_stack
1768 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1769 		    struct printf_spec spec, const char *fmt)
1770 {
1771 	char output[sizeof("0123 little-endian (0x01234567)")];
1772 	char *p = output;
1773 	unsigned int i;
1774 	u32 val;
1775 
1776 	if (fmt[1] != 'c' || fmt[2] != 'c')
1777 		return error_string(buf, end, "(%p4?)", spec);
1778 
1779 	if (check_pointer(&buf, end, fourcc, spec))
1780 		return buf;
1781 
1782 	val = *fourcc & ~BIT(31);
1783 
1784 	for (i = 0; i < sizeof(*fourcc); i++) {
1785 		unsigned char c = val >> (i * 8);
1786 
1787 		/* Print non-control ASCII characters as-is, dot otherwise */
1788 		*p++ = isascii(c) && isprint(c) ? c : '.';
1789 	}
1790 
1791 	strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian");
1792 	p += strlen(p);
1793 
1794 	*p++ = ' ';
1795 	*p++ = '(';
1796 	p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32));
1797 	*p++ = ')';
1798 	*p = '\0';
1799 
1800 	return string(buf, end, output, spec);
1801 }
1802 
1803 static noinline_for_stack
1804 char *address_val(char *buf, char *end, const void *addr,
1805 		  struct printf_spec spec, const char *fmt)
1806 {
1807 	unsigned long long num;
1808 	int size;
1809 
1810 	if (check_pointer(&buf, end, addr, spec))
1811 		return buf;
1812 
1813 	switch (fmt[1]) {
1814 	case 'd':
1815 		num = *(const dma_addr_t *)addr;
1816 		size = sizeof(dma_addr_t);
1817 		break;
1818 	case 'p':
1819 	default:
1820 		num = *(const phys_addr_t *)addr;
1821 		size = sizeof(phys_addr_t);
1822 		break;
1823 	}
1824 
1825 	return special_hex_number(buf, end, num, size);
1826 }
1827 
1828 static noinline_for_stack
1829 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1830 {
1831 	int year = tm->tm_year + (r ? 0 : 1900);
1832 	int mon = tm->tm_mon + (r ? 0 : 1);
1833 
1834 	buf = number(buf, end, year, default_dec04_spec);
1835 	if (buf < end)
1836 		*buf = '-';
1837 	buf++;
1838 
1839 	buf = number(buf, end, mon, default_dec02_spec);
1840 	if (buf < end)
1841 		*buf = '-';
1842 	buf++;
1843 
1844 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1845 }
1846 
1847 static noinline_for_stack
1848 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1849 {
1850 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1851 	if (buf < end)
1852 		*buf = ':';
1853 	buf++;
1854 
1855 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1856 	if (buf < end)
1857 		*buf = ':';
1858 	buf++;
1859 
1860 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1861 }
1862 
1863 static noinline_for_stack
1864 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1865 	      struct printf_spec spec, const char *fmt)
1866 {
1867 	bool have_t = true, have_d = true;
1868 	bool raw = false, iso8601_separator = true;
1869 	bool found = true;
1870 	int count = 2;
1871 
1872 	if (check_pointer(&buf, end, tm, spec))
1873 		return buf;
1874 
1875 	switch (fmt[count]) {
1876 	case 'd':
1877 		have_t = false;
1878 		count++;
1879 		break;
1880 	case 't':
1881 		have_d = false;
1882 		count++;
1883 		break;
1884 	}
1885 
1886 	do {
1887 		switch (fmt[count++]) {
1888 		case 'r':
1889 			raw = true;
1890 			break;
1891 		case 's':
1892 			iso8601_separator = false;
1893 			break;
1894 		default:
1895 			found = false;
1896 			break;
1897 		}
1898 	} while (found);
1899 
1900 	if (have_d)
1901 		buf = date_str(buf, end, tm, raw);
1902 	if (have_d && have_t) {
1903 		if (buf < end)
1904 			*buf = iso8601_separator ? 'T' : ' ';
1905 		buf++;
1906 	}
1907 	if (have_t)
1908 		buf = time_str(buf, end, tm, raw);
1909 
1910 	return buf;
1911 }
1912 
1913 static noinline_for_stack
1914 char *time64_str(char *buf, char *end, const time64_t time,
1915 		 struct printf_spec spec, const char *fmt)
1916 {
1917 	struct rtc_time rtc_time;
1918 	struct tm tm;
1919 
1920 	time64_to_tm(time, 0, &tm);
1921 
1922 	rtc_time.tm_sec = tm.tm_sec;
1923 	rtc_time.tm_min = tm.tm_min;
1924 	rtc_time.tm_hour = tm.tm_hour;
1925 	rtc_time.tm_mday = tm.tm_mday;
1926 	rtc_time.tm_mon = tm.tm_mon;
1927 	rtc_time.tm_year = tm.tm_year;
1928 	rtc_time.tm_wday = tm.tm_wday;
1929 	rtc_time.tm_yday = tm.tm_yday;
1930 
1931 	rtc_time.tm_isdst = 0;
1932 
1933 	return rtc_str(buf, end, &rtc_time, spec, fmt);
1934 }
1935 
1936 static noinline_for_stack
1937 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1938 		    const char *fmt)
1939 {
1940 	switch (fmt[1]) {
1941 	case 'R':
1942 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1943 	case 'T':
1944 		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1945 	default:
1946 		return error_string(buf, end, "(%pt?)", spec);
1947 	}
1948 }
1949 
1950 static noinline_for_stack
1951 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1952 	    const char *fmt)
1953 {
1954 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1955 		return error_string(buf, end, "(%pC?)", spec);
1956 
1957 	if (check_pointer(&buf, end, clk, spec))
1958 		return buf;
1959 
1960 	switch (fmt[1]) {
1961 	case 'n':
1962 	default:
1963 #ifdef CONFIG_COMMON_CLK
1964 		return string(buf, end, __clk_get_name(clk), spec);
1965 #else
1966 		return ptr_to_id(buf, end, clk, spec);
1967 #endif
1968 	}
1969 }
1970 
1971 static
1972 char *format_flags(char *buf, char *end, unsigned long flags,
1973 					const struct trace_print_flags *names)
1974 {
1975 	unsigned long mask;
1976 
1977 	for ( ; flags && names->name; names++) {
1978 		mask = names->mask;
1979 		if ((flags & mask) != mask)
1980 			continue;
1981 
1982 		buf = string(buf, end, names->name, default_str_spec);
1983 
1984 		flags &= ~mask;
1985 		if (flags) {
1986 			if (buf < end)
1987 				*buf = '|';
1988 			buf++;
1989 		}
1990 	}
1991 
1992 	if (flags)
1993 		buf = number(buf, end, flags, default_flag_spec);
1994 
1995 	return buf;
1996 }
1997 
1998 struct page_flags_fields {
1999 	int width;
2000 	int shift;
2001 	int mask;
2002 	const struct printf_spec *spec;
2003 	const char *name;
2004 };
2005 
2006 static const struct page_flags_fields pff[] = {
2007 	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2008 	 &default_dec_spec, "section"},
2009 	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2010 	 &default_dec_spec, "node"},
2011 	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2012 	 &default_dec_spec, "zone"},
2013 	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2014 	 &default_flag_spec, "lastcpupid"},
2015 	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2016 	 &default_flag_spec, "kasantag"},
2017 };
2018 
2019 static
2020 char *format_page_flags(char *buf, char *end, unsigned long flags)
2021 {
2022 	unsigned long main_flags = flags & PAGEFLAGS_MASK;
2023 	bool append = false;
2024 	int i;
2025 
2026 	buf = number(buf, end, flags, default_flag_spec);
2027 	if (buf < end)
2028 		*buf = '(';
2029 	buf++;
2030 
2031 	/* Page flags from the main area. */
2032 	if (main_flags) {
2033 		buf = format_flags(buf, end, main_flags, pageflag_names);
2034 		append = true;
2035 	}
2036 
2037 	/* Page flags from the fields area */
2038 	for (i = 0; i < ARRAY_SIZE(pff); i++) {
2039 		/* Skip undefined fields. */
2040 		if (!pff[i].width)
2041 			continue;
2042 
2043 		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2044 		if (append) {
2045 			if (buf < end)
2046 				*buf = '|';
2047 			buf++;
2048 		}
2049 
2050 		buf = string(buf, end, pff[i].name, default_str_spec);
2051 		if (buf < end)
2052 			*buf = '=';
2053 		buf++;
2054 		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2055 			     *pff[i].spec);
2056 
2057 		append = true;
2058 	}
2059 	if (buf < end)
2060 		*buf = ')';
2061 	buf++;
2062 
2063 	return buf;
2064 }
2065 
2066 static noinline_for_stack
2067 char *flags_string(char *buf, char *end, void *flags_ptr,
2068 		   struct printf_spec spec, const char *fmt)
2069 {
2070 	unsigned long flags;
2071 	const struct trace_print_flags *names;
2072 
2073 	if (check_pointer(&buf, end, flags_ptr, spec))
2074 		return buf;
2075 
2076 	switch (fmt[1]) {
2077 	case 'p':
2078 		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2079 	case 'v':
2080 		flags = *(unsigned long *)flags_ptr;
2081 		names = vmaflag_names;
2082 		break;
2083 	case 'g':
2084 		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2085 		names = gfpflag_names;
2086 		break;
2087 	default:
2088 		return error_string(buf, end, "(%pG?)", spec);
2089 	}
2090 
2091 	return format_flags(buf, end, flags, names);
2092 }
2093 
2094 static noinline_for_stack
2095 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2096 			      char *end)
2097 {
2098 	int depth;
2099 
2100 	/* Loop starting from the root node to the current node. */
2101 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2102 		struct fwnode_handle *__fwnode =
2103 			fwnode_get_nth_parent(fwnode, depth);
2104 
2105 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2106 			     default_str_spec);
2107 		buf = string(buf, end, fwnode_get_name(__fwnode),
2108 			     default_str_spec);
2109 
2110 		fwnode_handle_put(__fwnode);
2111 	}
2112 
2113 	return buf;
2114 }
2115 
2116 static noinline_for_stack
2117 char *device_node_string(char *buf, char *end, struct device_node *dn,
2118 			 struct printf_spec spec, const char *fmt)
2119 {
2120 	char tbuf[sizeof("xxxx") + 1];
2121 	const char *p;
2122 	int ret;
2123 	char *buf_start = buf;
2124 	struct property *prop;
2125 	bool has_mult, pass;
2126 
2127 	struct printf_spec str_spec = spec;
2128 	str_spec.field_width = -1;
2129 
2130 	if (fmt[0] != 'F')
2131 		return error_string(buf, end, "(%pO?)", spec);
2132 
2133 	if (!IS_ENABLED(CONFIG_OF))
2134 		return error_string(buf, end, "(%pOF?)", spec);
2135 
2136 	if (check_pointer(&buf, end, dn, spec))
2137 		return buf;
2138 
2139 	/* simple case without anything any more format specifiers */
2140 	fmt++;
2141 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2142 		fmt = "f";
2143 
2144 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2145 		int precision;
2146 		if (pass) {
2147 			if (buf < end)
2148 				*buf = ':';
2149 			buf++;
2150 		}
2151 
2152 		switch (*fmt) {
2153 		case 'f':	/* full_name */
2154 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2155 						      end);
2156 			break;
2157 		case 'n':	/* name */
2158 			p = fwnode_get_name(of_fwnode_handle(dn));
2159 			precision = str_spec.precision;
2160 			str_spec.precision = strchrnul(p, '@') - p;
2161 			buf = string(buf, end, p, str_spec);
2162 			str_spec.precision = precision;
2163 			break;
2164 		case 'p':	/* phandle */
2165 			buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2166 			break;
2167 		case 'P':	/* path-spec */
2168 			p = fwnode_get_name(of_fwnode_handle(dn));
2169 			if (!p[1])
2170 				p = "/";
2171 			buf = string(buf, end, p, str_spec);
2172 			break;
2173 		case 'F':	/* flags */
2174 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2175 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2176 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2177 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2178 			tbuf[4] = 0;
2179 			buf = string_nocheck(buf, end, tbuf, str_spec);
2180 			break;
2181 		case 'c':	/* major compatible string */
2182 			ret = of_property_read_string(dn, "compatible", &p);
2183 			if (!ret)
2184 				buf = string(buf, end, p, str_spec);
2185 			break;
2186 		case 'C':	/* full compatible string */
2187 			has_mult = false;
2188 			of_property_for_each_string(dn, "compatible", prop, p) {
2189 				if (has_mult)
2190 					buf = string_nocheck(buf, end, ",", str_spec);
2191 				buf = string_nocheck(buf, end, "\"", str_spec);
2192 				buf = string(buf, end, p, str_spec);
2193 				buf = string_nocheck(buf, end, "\"", str_spec);
2194 
2195 				has_mult = true;
2196 			}
2197 			break;
2198 		default:
2199 			break;
2200 		}
2201 	}
2202 
2203 	return widen_string(buf, buf - buf_start, end, spec);
2204 }
2205 
2206 static noinline_for_stack
2207 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2208 		    struct printf_spec spec, const char *fmt)
2209 {
2210 	struct printf_spec str_spec = spec;
2211 	char *buf_start = buf;
2212 
2213 	str_spec.field_width = -1;
2214 
2215 	if (*fmt != 'w')
2216 		return error_string(buf, end, "(%pf?)", spec);
2217 
2218 	if (check_pointer(&buf, end, fwnode, spec))
2219 		return buf;
2220 
2221 	fmt++;
2222 
2223 	switch (*fmt) {
2224 	case 'P':	/* name */
2225 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2226 		break;
2227 	case 'f':	/* full_name */
2228 	default:
2229 		buf = fwnode_full_name_string(fwnode, buf, end);
2230 		break;
2231 	}
2232 
2233 	return widen_string(buf, buf - buf_start, end, spec);
2234 }
2235 
2236 /* Disable pointer hashing if requested */
2237 bool no_hash_pointers __ro_after_init;
2238 EXPORT_SYMBOL_GPL(no_hash_pointers);
2239 
2240 int __init no_hash_pointers_enable(char *str)
2241 {
2242 	if (no_hash_pointers)
2243 		return 0;
2244 
2245 	no_hash_pointers = true;
2246 
2247 	pr_warn("**********************************************************\n");
2248 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2249 	pr_warn("**                                                      **\n");
2250 	pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2251 	pr_warn("** via the console, logs, and other interfaces. This    **\n");
2252 	pr_warn("** might reduce the security of your system.            **\n");
2253 	pr_warn("**                                                      **\n");
2254 	pr_warn("** If you see this message and you are not debugging    **\n");
2255 	pr_warn("** the kernel, report this immediately to your system   **\n");
2256 	pr_warn("** administrator!                                       **\n");
2257 	pr_warn("**                                                      **\n");
2258 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2259 	pr_warn("**********************************************************\n");
2260 
2261 	return 0;
2262 }
2263 early_param("no_hash_pointers", no_hash_pointers_enable);
2264 
2265 /*
2266  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2267  * by an extra set of alphanumeric characters that are extended format
2268  * specifiers.
2269  *
2270  * Please update scripts/checkpatch.pl when adding/removing conversion
2271  * characters.  (Search for "check for vsprintf extension").
2272  *
2273  * Right now we handle:
2274  *
2275  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2276  * - 's' For symbolic direct pointers (or function descriptors) without offset
2277  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2278  * - 'S[R]b' as above with module build ID (for use in backtraces)
2279  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2280  *	    %ps and %pS. Be careful when re-using these specifiers.
2281  * - 'B' For backtraced symbolic direct pointers with offset
2282  * - 'Bb' as above with module build ID (for use in backtraces)
2283  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2284  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2285  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2286  *       width which must be explicitly specified either as part of the
2287  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2288  *       range-list format instead of hex format
2289  * - 'M' For a 6-byte MAC address, it prints the address in the
2290  *       usual colon-separated hex notation
2291  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2292  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2293  *       with a dash-separated hex notation
2294  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2295  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2296  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2297  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2298  *       [S][pfs]
2299  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2300  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2301  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2302  *       IPv6 omits the colons (01020304...0f)
2303  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2304  *       [S][pfs]
2305  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2306  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2307  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2308  * - 'I[6S]c' for IPv6 addresses printed as specified by
2309  *       https://tools.ietf.org/html/rfc5952
2310  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2311  *                of the following flags (see string_escape_mem() for the
2312  *                details):
2313  *                  a - ESCAPE_ANY
2314  *                  c - ESCAPE_SPECIAL
2315  *                  h - ESCAPE_HEX
2316  *                  n - ESCAPE_NULL
2317  *                  o - ESCAPE_OCTAL
2318  *                  p - ESCAPE_NP
2319  *                  s - ESCAPE_SPACE
2320  *                By default ESCAPE_ANY_NP is used.
2321  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2322  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2323  *       Options for %pU are:
2324  *         b big endian lower case hex (default)
2325  *         B big endian UPPER case hex
2326  *         l little endian lower case hex
2327  *         L little endian UPPER case hex
2328  *           big endian output byte order is:
2329  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2330  *           little endian output byte order is:
2331  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2332  * - 'V' For a struct va_format which contains a format string * and va_list *,
2333  *       call vsnprintf(->format, *->va_list).
2334  *       Implements a "recursive vsnprintf".
2335  *       Do not use this feature without some mechanism to verify the
2336  *       correctness of the format string and va_list arguments.
2337  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2338  *       Use only for procfs, sysfs and similar files, not printk(); please
2339  *       read the documentation (path below) first.
2340  * - 'NF' For a netdev_features_t
2341  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2342  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2343  *            a certain separator (' ' by default):
2344  *              C colon
2345  *              D dash
2346  *              N no separator
2347  *            The maximum supported length is 64 bytes of the input. Consider
2348  *            to use print_hex_dump() for the larger input.
2349  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2350  *           (default assumed to be phys_addr_t, passed by reference)
2351  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2352  * - 'D[234]' Same as 'd' but for a struct file
2353  * - 'g' For block_device name (gendisk + partition number)
2354  * - 't[RT][dt][r][s]' For time and date as represented by:
2355  *      R    struct rtc_time
2356  *      T    time64_t
2357  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2358  *       (legacy clock framework) of the clock
2359  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2360  *        (legacy clock framework) of the clock
2361  * - 'G' For flags to be printed as a collection of symbolic strings that would
2362  *       construct the specific value. Supported flags given by option:
2363  *       p page flags (see struct page) given as pointer to unsigned long
2364  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2365  *       v vma flags (VM_*) given as pointer to unsigned long
2366  * - 'OF[fnpPcCF]'  For a device tree object
2367  *                  Without any optional arguments prints the full_name
2368  *                  f device node full_name
2369  *                  n device node name
2370  *                  p device node phandle
2371  *                  P device node path spec (name + @unit)
2372  *                  F device node flags
2373  *                  c major compatible string
2374  *                  C full compatible string
2375  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2376  *		Without an option prints the full name of the node
2377  *		f full name
2378  *		P node name, including a possible unit address
2379  * - 'x' For printing the address unmodified. Equivalent to "%lx".
2380  *       Please read the documentation (path below) before using!
2381  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2382  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2383  *           or user (u) memory to probe, and:
2384  *              s a string, equivalent to "%s" on direct vsnprintf() use
2385  *
2386  * ** When making changes please also update:
2387  *	Documentation/core-api/printk-formats.rst
2388  *
2389  * Note: The default behaviour (unadorned %p) is to hash the address,
2390  * rendering it useful as a unique identifier.
2391  */
2392 static noinline_for_stack
2393 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2394 	      struct printf_spec spec)
2395 {
2396 	switch (*fmt) {
2397 	case 'S':
2398 	case 's':
2399 		ptr = dereference_symbol_descriptor(ptr);
2400 		fallthrough;
2401 	case 'B':
2402 		return symbol_string(buf, end, ptr, spec, fmt);
2403 	case 'R':
2404 	case 'r':
2405 		return resource_string(buf, end, ptr, spec, fmt);
2406 	case 'h':
2407 		return hex_string(buf, end, ptr, spec, fmt);
2408 	case 'b':
2409 		switch (fmt[1]) {
2410 		case 'l':
2411 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2412 		default:
2413 			return bitmap_string(buf, end, ptr, spec, fmt);
2414 		}
2415 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2416 	case 'm':			/* Contiguous: 000102030405 */
2417 					/* [mM]F (FDDI) */
2418 					/* [mM]R (Reverse order; Bluetooth) */
2419 		return mac_address_string(buf, end, ptr, spec, fmt);
2420 	case 'I':			/* Formatted IP supported
2421 					 * 4:	1.2.3.4
2422 					 * 6:	0001:0203:...:0708
2423 					 * 6c:	1::708 or 1::1.2.3.4
2424 					 */
2425 	case 'i':			/* Contiguous:
2426 					 * 4:	001.002.003.004
2427 					 * 6:   000102...0f
2428 					 */
2429 		return ip_addr_string(buf, end, ptr, spec, fmt);
2430 	case 'E':
2431 		return escaped_string(buf, end, ptr, spec, fmt);
2432 	case 'U':
2433 		return uuid_string(buf, end, ptr, spec, fmt);
2434 	case 'V':
2435 		return va_format(buf, end, ptr, spec, fmt);
2436 	case 'K':
2437 		return restricted_pointer(buf, end, ptr, spec);
2438 	case 'N':
2439 		return netdev_bits(buf, end, ptr, spec, fmt);
2440 	case '4':
2441 		return fourcc_string(buf, end, ptr, spec, fmt);
2442 	case 'a':
2443 		return address_val(buf, end, ptr, spec, fmt);
2444 	case 'd':
2445 		return dentry_name(buf, end, ptr, spec, fmt);
2446 	case 't':
2447 		return time_and_date(buf, end, ptr, spec, fmt);
2448 	case 'C':
2449 		return clock(buf, end, ptr, spec, fmt);
2450 	case 'D':
2451 		return file_dentry_name(buf, end, ptr, spec, fmt);
2452 #ifdef CONFIG_BLOCK
2453 	case 'g':
2454 		return bdev_name(buf, end, ptr, spec, fmt);
2455 #endif
2456 
2457 	case 'G':
2458 		return flags_string(buf, end, ptr, spec, fmt);
2459 	case 'O':
2460 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2461 	case 'f':
2462 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2463 	case 'x':
2464 		return pointer_string(buf, end, ptr, spec);
2465 	case 'e':
2466 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2467 		if (!IS_ERR(ptr))
2468 			break;
2469 		return err_ptr(buf, end, ptr, spec);
2470 	case 'u':
2471 	case 'k':
2472 		switch (fmt[1]) {
2473 		case 's':
2474 			return string(buf, end, ptr, spec);
2475 		default:
2476 			return error_string(buf, end, "(einval)", spec);
2477 		}
2478 	}
2479 
2480 	/*
2481 	 * default is to _not_ leak addresses, so hash before printing,
2482 	 * unless no_hash_pointers is specified on the command line.
2483 	 */
2484 	if (unlikely(no_hash_pointers))
2485 		return pointer_string(buf, end, ptr, spec);
2486 	else
2487 		return ptr_to_id(buf, end, ptr, spec);
2488 }
2489 
2490 /*
2491  * Helper function to decode printf style format.
2492  * Each call decode a token from the format and return the
2493  * number of characters read (or likely the delta where it wants
2494  * to go on the next call).
2495  * The decoded token is returned through the parameters
2496  *
2497  * 'h', 'l', or 'L' for integer fields
2498  * 'z' support added 23/7/1999 S.H.
2499  * 'z' changed to 'Z' --davidm 1/25/99
2500  * 'Z' changed to 'z' --adobriyan 2017-01-25
2501  * 't' added for ptrdiff_t
2502  *
2503  * @fmt: the format string
2504  * @type of the token returned
2505  * @flags: various flags such as +, -, # tokens..
2506  * @field_width: overwritten width
2507  * @base: base of the number (octal, hex, ...)
2508  * @precision: precision of a number
2509  * @qualifier: qualifier of a number (long, size_t, ...)
2510  */
2511 static noinline_for_stack
2512 int format_decode(const char *fmt, struct printf_spec *spec)
2513 {
2514 	const char *start = fmt;
2515 	char qualifier;
2516 
2517 	/* we finished early by reading the field width */
2518 	if (spec->type == FORMAT_TYPE_WIDTH) {
2519 		if (spec->field_width < 0) {
2520 			spec->field_width = -spec->field_width;
2521 			spec->flags |= LEFT;
2522 		}
2523 		spec->type = FORMAT_TYPE_NONE;
2524 		goto precision;
2525 	}
2526 
2527 	/* we finished early by reading the precision */
2528 	if (spec->type == FORMAT_TYPE_PRECISION) {
2529 		if (spec->precision < 0)
2530 			spec->precision = 0;
2531 
2532 		spec->type = FORMAT_TYPE_NONE;
2533 		goto qualifier;
2534 	}
2535 
2536 	/* By default */
2537 	spec->type = FORMAT_TYPE_NONE;
2538 
2539 	for (; *fmt ; ++fmt) {
2540 		if (*fmt == '%')
2541 			break;
2542 	}
2543 
2544 	/* Return the current non-format string */
2545 	if (fmt != start || !*fmt)
2546 		return fmt - start;
2547 
2548 	/* Process flags */
2549 	spec->flags = 0;
2550 
2551 	while (1) { /* this also skips first '%' */
2552 		bool found = true;
2553 
2554 		++fmt;
2555 
2556 		switch (*fmt) {
2557 		case '-': spec->flags |= LEFT;    break;
2558 		case '+': spec->flags |= PLUS;    break;
2559 		case ' ': spec->flags |= SPACE;   break;
2560 		case '#': spec->flags |= SPECIAL; break;
2561 		case '0': spec->flags |= ZEROPAD; break;
2562 		default:  found = false;
2563 		}
2564 
2565 		if (!found)
2566 			break;
2567 	}
2568 
2569 	/* get field width */
2570 	spec->field_width = -1;
2571 
2572 	if (isdigit(*fmt))
2573 		spec->field_width = skip_atoi(&fmt);
2574 	else if (*fmt == '*') {
2575 		/* it's the next argument */
2576 		spec->type = FORMAT_TYPE_WIDTH;
2577 		return ++fmt - start;
2578 	}
2579 
2580 precision:
2581 	/* get the precision */
2582 	spec->precision = -1;
2583 	if (*fmt == '.') {
2584 		++fmt;
2585 		if (isdigit(*fmt)) {
2586 			spec->precision = skip_atoi(&fmt);
2587 			if (spec->precision < 0)
2588 				spec->precision = 0;
2589 		} else if (*fmt == '*') {
2590 			/* it's the next argument */
2591 			spec->type = FORMAT_TYPE_PRECISION;
2592 			return ++fmt - start;
2593 		}
2594 	}
2595 
2596 qualifier:
2597 	/* get the conversion qualifier */
2598 	qualifier = 0;
2599 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2600 	    *fmt == 'z' || *fmt == 't') {
2601 		qualifier = *fmt++;
2602 		if (unlikely(qualifier == *fmt)) {
2603 			if (qualifier == 'l') {
2604 				qualifier = 'L';
2605 				++fmt;
2606 			} else if (qualifier == 'h') {
2607 				qualifier = 'H';
2608 				++fmt;
2609 			}
2610 		}
2611 	}
2612 
2613 	/* default base */
2614 	spec->base = 10;
2615 	switch (*fmt) {
2616 	case 'c':
2617 		spec->type = FORMAT_TYPE_CHAR;
2618 		return ++fmt - start;
2619 
2620 	case 's':
2621 		spec->type = FORMAT_TYPE_STR;
2622 		return ++fmt - start;
2623 
2624 	case 'p':
2625 		spec->type = FORMAT_TYPE_PTR;
2626 		return ++fmt - start;
2627 
2628 	case '%':
2629 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2630 		return ++fmt - start;
2631 
2632 	/* integer number formats - set up the flags and "break" */
2633 	case 'o':
2634 		spec->base = 8;
2635 		break;
2636 
2637 	case 'x':
2638 		spec->flags |= SMALL;
2639 		fallthrough;
2640 
2641 	case 'X':
2642 		spec->base = 16;
2643 		break;
2644 
2645 	case 'd':
2646 	case 'i':
2647 		spec->flags |= SIGN;
2648 		break;
2649 	case 'u':
2650 		break;
2651 
2652 	case 'n':
2653 		/*
2654 		 * Since %n poses a greater security risk than
2655 		 * utility, treat it as any other invalid or
2656 		 * unsupported format specifier.
2657 		 */
2658 		fallthrough;
2659 
2660 	default:
2661 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2662 		spec->type = FORMAT_TYPE_INVALID;
2663 		return fmt - start;
2664 	}
2665 
2666 	if (qualifier == 'L')
2667 		spec->type = FORMAT_TYPE_LONG_LONG;
2668 	else if (qualifier == 'l') {
2669 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2670 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2671 	} else if (qualifier == 'z') {
2672 		spec->type = FORMAT_TYPE_SIZE_T;
2673 	} else if (qualifier == 't') {
2674 		spec->type = FORMAT_TYPE_PTRDIFF;
2675 	} else if (qualifier == 'H') {
2676 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2677 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2678 	} else if (qualifier == 'h') {
2679 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2680 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2681 	} else {
2682 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2683 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2684 	}
2685 
2686 	return ++fmt - start;
2687 }
2688 
2689 static void
2690 set_field_width(struct printf_spec *spec, int width)
2691 {
2692 	spec->field_width = width;
2693 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2694 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2695 	}
2696 }
2697 
2698 static void
2699 set_precision(struct printf_spec *spec, int prec)
2700 {
2701 	spec->precision = prec;
2702 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2703 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2704 	}
2705 }
2706 
2707 /**
2708  * vsnprintf - Format a string and place it in a buffer
2709  * @buf: The buffer to place the result into
2710  * @size: The size of the buffer, including the trailing null space
2711  * @fmt: The format string to use
2712  * @args: Arguments for the format string
2713  *
2714  * This function generally follows C99 vsnprintf, but has some
2715  * extensions and a few limitations:
2716  *
2717  *  - ``%n`` is unsupported
2718  *  - ``%p*`` is handled by pointer()
2719  *
2720  * See pointer() or Documentation/core-api/printk-formats.rst for more
2721  * extensive description.
2722  *
2723  * **Please update the documentation in both places when making changes**
2724  *
2725  * The return value is the number of characters which would
2726  * be generated for the given input, excluding the trailing
2727  * '\0', as per ISO C99. If you want to have the exact
2728  * number of characters written into @buf as return value
2729  * (not including the trailing '\0'), use vscnprintf(). If the
2730  * return is greater than or equal to @size, the resulting
2731  * string is truncated.
2732  *
2733  * If you're not already dealing with a va_list consider using snprintf().
2734  */
2735 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2736 {
2737 	unsigned long long num;
2738 	char *str, *end;
2739 	struct printf_spec spec = {0};
2740 
2741 	/* Reject out-of-range values early.  Large positive sizes are
2742 	   used for unknown buffer sizes. */
2743 	if (WARN_ON_ONCE(size > INT_MAX))
2744 		return 0;
2745 
2746 	str = buf;
2747 	end = buf + size;
2748 
2749 	/* Make sure end is always >= buf */
2750 	if (end < buf) {
2751 		end = ((void *)-1);
2752 		size = end - buf;
2753 	}
2754 
2755 	while (*fmt) {
2756 		const char *old_fmt = fmt;
2757 		int read = format_decode(fmt, &spec);
2758 
2759 		fmt += read;
2760 
2761 		switch (spec.type) {
2762 		case FORMAT_TYPE_NONE: {
2763 			int copy = read;
2764 			if (str < end) {
2765 				if (copy > end - str)
2766 					copy = end - str;
2767 				memcpy(str, old_fmt, copy);
2768 			}
2769 			str += read;
2770 			break;
2771 		}
2772 
2773 		case FORMAT_TYPE_WIDTH:
2774 			set_field_width(&spec, va_arg(args, int));
2775 			break;
2776 
2777 		case FORMAT_TYPE_PRECISION:
2778 			set_precision(&spec, va_arg(args, int));
2779 			break;
2780 
2781 		case FORMAT_TYPE_CHAR: {
2782 			char c;
2783 
2784 			if (!(spec.flags & LEFT)) {
2785 				while (--spec.field_width > 0) {
2786 					if (str < end)
2787 						*str = ' ';
2788 					++str;
2789 
2790 				}
2791 			}
2792 			c = (unsigned char) va_arg(args, int);
2793 			if (str < end)
2794 				*str = c;
2795 			++str;
2796 			while (--spec.field_width > 0) {
2797 				if (str < end)
2798 					*str = ' ';
2799 				++str;
2800 			}
2801 			break;
2802 		}
2803 
2804 		case FORMAT_TYPE_STR:
2805 			str = string(str, end, va_arg(args, char *), spec);
2806 			break;
2807 
2808 		case FORMAT_TYPE_PTR:
2809 			str = pointer(fmt, str, end, va_arg(args, void *),
2810 				      spec);
2811 			while (isalnum(*fmt))
2812 				fmt++;
2813 			break;
2814 
2815 		case FORMAT_TYPE_PERCENT_CHAR:
2816 			if (str < end)
2817 				*str = '%';
2818 			++str;
2819 			break;
2820 
2821 		case FORMAT_TYPE_INVALID:
2822 			/*
2823 			 * Presumably the arguments passed gcc's type
2824 			 * checking, but there is no safe or sane way
2825 			 * for us to continue parsing the format and
2826 			 * fetching from the va_list; the remaining
2827 			 * specifiers and arguments would be out of
2828 			 * sync.
2829 			 */
2830 			goto out;
2831 
2832 		default:
2833 			switch (spec.type) {
2834 			case FORMAT_TYPE_LONG_LONG:
2835 				num = va_arg(args, long long);
2836 				break;
2837 			case FORMAT_TYPE_ULONG:
2838 				num = va_arg(args, unsigned long);
2839 				break;
2840 			case FORMAT_TYPE_LONG:
2841 				num = va_arg(args, long);
2842 				break;
2843 			case FORMAT_TYPE_SIZE_T:
2844 				if (spec.flags & SIGN)
2845 					num = va_arg(args, ssize_t);
2846 				else
2847 					num = va_arg(args, size_t);
2848 				break;
2849 			case FORMAT_TYPE_PTRDIFF:
2850 				num = va_arg(args, ptrdiff_t);
2851 				break;
2852 			case FORMAT_TYPE_UBYTE:
2853 				num = (unsigned char) va_arg(args, int);
2854 				break;
2855 			case FORMAT_TYPE_BYTE:
2856 				num = (signed char) va_arg(args, int);
2857 				break;
2858 			case FORMAT_TYPE_USHORT:
2859 				num = (unsigned short) va_arg(args, int);
2860 				break;
2861 			case FORMAT_TYPE_SHORT:
2862 				num = (short) va_arg(args, int);
2863 				break;
2864 			case FORMAT_TYPE_INT:
2865 				num = (int) va_arg(args, int);
2866 				break;
2867 			default:
2868 				num = va_arg(args, unsigned int);
2869 			}
2870 
2871 			str = number(str, end, num, spec);
2872 		}
2873 	}
2874 
2875 out:
2876 	if (size > 0) {
2877 		if (str < end)
2878 			*str = '\0';
2879 		else
2880 			end[-1] = '\0';
2881 	}
2882 
2883 	/* the trailing null byte doesn't count towards the total */
2884 	return str-buf;
2885 
2886 }
2887 EXPORT_SYMBOL(vsnprintf);
2888 
2889 /**
2890  * vscnprintf - Format a string and place it in a buffer
2891  * @buf: The buffer to place the result into
2892  * @size: The size of the buffer, including the trailing null space
2893  * @fmt: The format string to use
2894  * @args: Arguments for the format string
2895  *
2896  * The return value is the number of characters which have been written into
2897  * the @buf not including the trailing '\0'. If @size is == 0 the function
2898  * returns 0.
2899  *
2900  * If you're not already dealing with a va_list consider using scnprintf().
2901  *
2902  * See the vsnprintf() documentation for format string extensions over C99.
2903  */
2904 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2905 {
2906 	int i;
2907 
2908 	i = vsnprintf(buf, size, fmt, args);
2909 
2910 	if (likely(i < size))
2911 		return i;
2912 	if (size != 0)
2913 		return size - 1;
2914 	return 0;
2915 }
2916 EXPORT_SYMBOL(vscnprintf);
2917 
2918 /**
2919  * snprintf - Format a string and place it in a buffer
2920  * @buf: The buffer to place the result into
2921  * @size: The size of the buffer, including the trailing null space
2922  * @fmt: The format string to use
2923  * @...: Arguments for the format string
2924  *
2925  * The return value is the number of characters which would be
2926  * generated for the given input, excluding the trailing null,
2927  * as per ISO C99.  If the return is greater than or equal to
2928  * @size, the resulting string is truncated.
2929  *
2930  * See the vsnprintf() documentation for format string extensions over C99.
2931  */
2932 int snprintf(char *buf, size_t size, const char *fmt, ...)
2933 {
2934 	va_list args;
2935 	int i;
2936 
2937 	va_start(args, fmt);
2938 	i = vsnprintf(buf, size, fmt, args);
2939 	va_end(args);
2940 
2941 	return i;
2942 }
2943 EXPORT_SYMBOL(snprintf);
2944 
2945 /**
2946  * scnprintf - Format a string and place it in a buffer
2947  * @buf: The buffer to place the result into
2948  * @size: The size of the buffer, including the trailing null space
2949  * @fmt: The format string to use
2950  * @...: Arguments for the format string
2951  *
2952  * The return value is the number of characters written into @buf not including
2953  * the trailing '\0'. If @size is == 0 the function returns 0.
2954  */
2955 
2956 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2957 {
2958 	va_list args;
2959 	int i;
2960 
2961 	va_start(args, fmt);
2962 	i = vscnprintf(buf, size, fmt, args);
2963 	va_end(args);
2964 
2965 	return i;
2966 }
2967 EXPORT_SYMBOL(scnprintf);
2968 
2969 /**
2970  * vsprintf - Format a string and place it in a buffer
2971  * @buf: The buffer to place the result into
2972  * @fmt: The format string to use
2973  * @args: Arguments for the format string
2974  *
2975  * The function returns the number of characters written
2976  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2977  * buffer overflows.
2978  *
2979  * If you're not already dealing with a va_list consider using sprintf().
2980  *
2981  * See the vsnprintf() documentation for format string extensions over C99.
2982  */
2983 int vsprintf(char *buf, const char *fmt, va_list args)
2984 {
2985 	return vsnprintf(buf, INT_MAX, fmt, args);
2986 }
2987 EXPORT_SYMBOL(vsprintf);
2988 
2989 /**
2990  * sprintf - Format a string and place it in a buffer
2991  * @buf: The buffer to place the result into
2992  * @fmt: The format string to use
2993  * @...: Arguments for the format string
2994  *
2995  * The function returns the number of characters written
2996  * into @buf. Use snprintf() or scnprintf() in order to avoid
2997  * buffer overflows.
2998  *
2999  * See the vsnprintf() documentation for format string extensions over C99.
3000  */
3001 int sprintf(char *buf, const char *fmt, ...)
3002 {
3003 	va_list args;
3004 	int i;
3005 
3006 	va_start(args, fmt);
3007 	i = vsnprintf(buf, INT_MAX, fmt, args);
3008 	va_end(args);
3009 
3010 	return i;
3011 }
3012 EXPORT_SYMBOL(sprintf);
3013 
3014 #ifdef CONFIG_BINARY_PRINTF
3015 /*
3016  * bprintf service:
3017  * vbin_printf() - VA arguments to binary data
3018  * bstr_printf() - Binary data to text string
3019  */
3020 
3021 /**
3022  * vbin_printf - Parse a format string and place args' binary value in a buffer
3023  * @bin_buf: The buffer to place args' binary value
3024  * @size: The size of the buffer(by words(32bits), not characters)
3025  * @fmt: The format string to use
3026  * @args: Arguments for the format string
3027  *
3028  * The format follows C99 vsnprintf, except %n is ignored, and its argument
3029  * is skipped.
3030  *
3031  * The return value is the number of words(32bits) which would be generated for
3032  * the given input.
3033  *
3034  * NOTE:
3035  * If the return value is greater than @size, the resulting bin_buf is NOT
3036  * valid for bstr_printf().
3037  */
3038 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3039 {
3040 	struct printf_spec spec = {0};
3041 	char *str, *end;
3042 	int width;
3043 
3044 	str = (char *)bin_buf;
3045 	end = (char *)(bin_buf + size);
3046 
3047 #define save_arg(type)							\
3048 ({									\
3049 	unsigned long long value;					\
3050 	if (sizeof(type) == 8) {					\
3051 		unsigned long long val8;				\
3052 		str = PTR_ALIGN(str, sizeof(u32));			\
3053 		val8 = va_arg(args, unsigned long long);		\
3054 		if (str + sizeof(type) <= end) {			\
3055 			*(u32 *)str = *(u32 *)&val8;			\
3056 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
3057 		}							\
3058 		value = val8;						\
3059 	} else {							\
3060 		unsigned int val4;					\
3061 		str = PTR_ALIGN(str, sizeof(type));			\
3062 		val4 = va_arg(args, int);				\
3063 		if (str + sizeof(type) <= end)				\
3064 			*(typeof(type) *)str = (type)(long)val4;	\
3065 		value = (unsigned long long)val4;			\
3066 	}								\
3067 	str += sizeof(type);						\
3068 	value;								\
3069 })
3070 
3071 	while (*fmt) {
3072 		int read = format_decode(fmt, &spec);
3073 
3074 		fmt += read;
3075 
3076 		switch (spec.type) {
3077 		case FORMAT_TYPE_NONE:
3078 		case FORMAT_TYPE_PERCENT_CHAR:
3079 			break;
3080 		case FORMAT_TYPE_INVALID:
3081 			goto out;
3082 
3083 		case FORMAT_TYPE_WIDTH:
3084 		case FORMAT_TYPE_PRECISION:
3085 			width = (int)save_arg(int);
3086 			/* Pointers may require the width */
3087 			if (*fmt == 'p')
3088 				set_field_width(&spec, width);
3089 			break;
3090 
3091 		case FORMAT_TYPE_CHAR:
3092 			save_arg(char);
3093 			break;
3094 
3095 		case FORMAT_TYPE_STR: {
3096 			const char *save_str = va_arg(args, char *);
3097 			const char *err_msg;
3098 			size_t len;
3099 
3100 			err_msg = check_pointer_msg(save_str);
3101 			if (err_msg)
3102 				save_str = err_msg;
3103 
3104 			len = strlen(save_str) + 1;
3105 			if (str + len < end)
3106 				memcpy(str, save_str, len);
3107 			str += len;
3108 			break;
3109 		}
3110 
3111 		case FORMAT_TYPE_PTR:
3112 			/* Dereferenced pointers must be done now */
3113 			switch (*fmt) {
3114 			/* Dereference of functions is still OK */
3115 			case 'S':
3116 			case 's':
3117 			case 'x':
3118 			case 'K':
3119 			case 'e':
3120 				save_arg(void *);
3121 				break;
3122 			default:
3123 				if (!isalnum(*fmt)) {
3124 					save_arg(void *);
3125 					break;
3126 				}
3127 				str = pointer(fmt, str, end, va_arg(args, void *),
3128 					      spec);
3129 				if (str + 1 < end)
3130 					*str++ = '\0';
3131 				else
3132 					end[-1] = '\0'; /* Must be nul terminated */
3133 			}
3134 			/* skip all alphanumeric pointer suffixes */
3135 			while (isalnum(*fmt))
3136 				fmt++;
3137 			break;
3138 
3139 		default:
3140 			switch (spec.type) {
3141 
3142 			case FORMAT_TYPE_LONG_LONG:
3143 				save_arg(long long);
3144 				break;
3145 			case FORMAT_TYPE_ULONG:
3146 			case FORMAT_TYPE_LONG:
3147 				save_arg(unsigned long);
3148 				break;
3149 			case FORMAT_TYPE_SIZE_T:
3150 				save_arg(size_t);
3151 				break;
3152 			case FORMAT_TYPE_PTRDIFF:
3153 				save_arg(ptrdiff_t);
3154 				break;
3155 			case FORMAT_TYPE_UBYTE:
3156 			case FORMAT_TYPE_BYTE:
3157 				save_arg(char);
3158 				break;
3159 			case FORMAT_TYPE_USHORT:
3160 			case FORMAT_TYPE_SHORT:
3161 				save_arg(short);
3162 				break;
3163 			default:
3164 				save_arg(int);
3165 			}
3166 		}
3167 	}
3168 
3169 out:
3170 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3171 #undef save_arg
3172 }
3173 EXPORT_SYMBOL_GPL(vbin_printf);
3174 
3175 /**
3176  * bstr_printf - Format a string from binary arguments and place it in a buffer
3177  * @buf: The buffer to place the result into
3178  * @size: The size of the buffer, including the trailing null space
3179  * @fmt: The format string to use
3180  * @bin_buf: Binary arguments for the format string
3181  *
3182  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3183  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3184  * a binary buffer that generated by vbin_printf.
3185  *
3186  * The format follows C99 vsnprintf, but has some extensions:
3187  *  see vsnprintf comment for details.
3188  *
3189  * The return value is the number of characters which would
3190  * be generated for the given input, excluding the trailing
3191  * '\0', as per ISO C99. If you want to have the exact
3192  * number of characters written into @buf as return value
3193  * (not including the trailing '\0'), use vscnprintf(). If the
3194  * return is greater than or equal to @size, the resulting
3195  * string is truncated.
3196  */
3197 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3198 {
3199 	struct printf_spec spec = {0};
3200 	char *str, *end;
3201 	const char *args = (const char *)bin_buf;
3202 
3203 	if (WARN_ON_ONCE(size > INT_MAX))
3204 		return 0;
3205 
3206 	str = buf;
3207 	end = buf + size;
3208 
3209 #define get_arg(type)							\
3210 ({									\
3211 	typeof(type) value;						\
3212 	if (sizeof(type) == 8) {					\
3213 		args = PTR_ALIGN(args, sizeof(u32));			\
3214 		*(u32 *)&value = *(u32 *)args;				\
3215 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3216 	} else {							\
3217 		args = PTR_ALIGN(args, sizeof(type));			\
3218 		value = *(typeof(type) *)args;				\
3219 	}								\
3220 	args += sizeof(type);						\
3221 	value;								\
3222 })
3223 
3224 	/* Make sure end is always >= buf */
3225 	if (end < buf) {
3226 		end = ((void *)-1);
3227 		size = end - buf;
3228 	}
3229 
3230 	while (*fmt) {
3231 		const char *old_fmt = fmt;
3232 		int read = format_decode(fmt, &spec);
3233 
3234 		fmt += read;
3235 
3236 		switch (spec.type) {
3237 		case FORMAT_TYPE_NONE: {
3238 			int copy = read;
3239 			if (str < end) {
3240 				if (copy > end - str)
3241 					copy = end - str;
3242 				memcpy(str, old_fmt, copy);
3243 			}
3244 			str += read;
3245 			break;
3246 		}
3247 
3248 		case FORMAT_TYPE_WIDTH:
3249 			set_field_width(&spec, get_arg(int));
3250 			break;
3251 
3252 		case FORMAT_TYPE_PRECISION:
3253 			set_precision(&spec, get_arg(int));
3254 			break;
3255 
3256 		case FORMAT_TYPE_CHAR: {
3257 			char c;
3258 
3259 			if (!(spec.flags & LEFT)) {
3260 				while (--spec.field_width > 0) {
3261 					if (str < end)
3262 						*str = ' ';
3263 					++str;
3264 				}
3265 			}
3266 			c = (unsigned char) get_arg(char);
3267 			if (str < end)
3268 				*str = c;
3269 			++str;
3270 			while (--spec.field_width > 0) {
3271 				if (str < end)
3272 					*str = ' ';
3273 				++str;
3274 			}
3275 			break;
3276 		}
3277 
3278 		case FORMAT_TYPE_STR: {
3279 			const char *str_arg = args;
3280 			args += strlen(str_arg) + 1;
3281 			str = string(str, end, (char *)str_arg, spec);
3282 			break;
3283 		}
3284 
3285 		case FORMAT_TYPE_PTR: {
3286 			bool process = false;
3287 			int copy, len;
3288 			/* Non function dereferences were already done */
3289 			switch (*fmt) {
3290 			case 'S':
3291 			case 's':
3292 			case 'x':
3293 			case 'K':
3294 			case 'e':
3295 				process = true;
3296 				break;
3297 			default:
3298 				if (!isalnum(*fmt)) {
3299 					process = true;
3300 					break;
3301 				}
3302 				/* Pointer dereference was already processed */
3303 				if (str < end) {
3304 					len = copy = strlen(args);
3305 					if (copy > end - str)
3306 						copy = end - str;
3307 					memcpy(str, args, copy);
3308 					str += len;
3309 					args += len + 1;
3310 				}
3311 			}
3312 			if (process)
3313 				str = pointer(fmt, str, end, get_arg(void *), spec);
3314 
3315 			while (isalnum(*fmt))
3316 				fmt++;
3317 			break;
3318 		}
3319 
3320 		case FORMAT_TYPE_PERCENT_CHAR:
3321 			if (str < end)
3322 				*str = '%';
3323 			++str;
3324 			break;
3325 
3326 		case FORMAT_TYPE_INVALID:
3327 			goto out;
3328 
3329 		default: {
3330 			unsigned long long num;
3331 
3332 			switch (spec.type) {
3333 
3334 			case FORMAT_TYPE_LONG_LONG:
3335 				num = get_arg(long long);
3336 				break;
3337 			case FORMAT_TYPE_ULONG:
3338 			case FORMAT_TYPE_LONG:
3339 				num = get_arg(unsigned long);
3340 				break;
3341 			case FORMAT_TYPE_SIZE_T:
3342 				num = get_arg(size_t);
3343 				break;
3344 			case FORMAT_TYPE_PTRDIFF:
3345 				num = get_arg(ptrdiff_t);
3346 				break;
3347 			case FORMAT_TYPE_UBYTE:
3348 				num = get_arg(unsigned char);
3349 				break;
3350 			case FORMAT_TYPE_BYTE:
3351 				num = get_arg(signed char);
3352 				break;
3353 			case FORMAT_TYPE_USHORT:
3354 				num = get_arg(unsigned short);
3355 				break;
3356 			case FORMAT_TYPE_SHORT:
3357 				num = get_arg(short);
3358 				break;
3359 			case FORMAT_TYPE_UINT:
3360 				num = get_arg(unsigned int);
3361 				break;
3362 			default:
3363 				num = get_arg(int);
3364 			}
3365 
3366 			str = number(str, end, num, spec);
3367 		} /* default: */
3368 		} /* switch(spec.type) */
3369 	} /* while(*fmt) */
3370 
3371 out:
3372 	if (size > 0) {
3373 		if (str < end)
3374 			*str = '\0';
3375 		else
3376 			end[-1] = '\0';
3377 	}
3378 
3379 #undef get_arg
3380 
3381 	/* the trailing null byte doesn't count towards the total */
3382 	return str - buf;
3383 }
3384 EXPORT_SYMBOL_GPL(bstr_printf);
3385 
3386 /**
3387  * bprintf - Parse a format string and place args' binary value in a buffer
3388  * @bin_buf: The buffer to place args' binary value
3389  * @size: The size of the buffer(by words(32bits), not characters)
3390  * @fmt: The format string to use
3391  * @...: Arguments for the format string
3392  *
3393  * The function returns the number of words(u32) written
3394  * into @bin_buf.
3395  */
3396 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3397 {
3398 	va_list args;
3399 	int ret;
3400 
3401 	va_start(args, fmt);
3402 	ret = vbin_printf(bin_buf, size, fmt, args);
3403 	va_end(args);
3404 
3405 	return ret;
3406 }
3407 EXPORT_SYMBOL_GPL(bprintf);
3408 
3409 #endif /* CONFIG_BINARY_PRINTF */
3410 
3411 /**
3412  * vsscanf - Unformat a buffer into a list of arguments
3413  * @buf:	input buffer
3414  * @fmt:	format of buffer
3415  * @args:	arguments
3416  */
3417 int vsscanf(const char *buf, const char *fmt, va_list args)
3418 {
3419 	const char *str = buf;
3420 	char *next;
3421 	char digit;
3422 	int num = 0;
3423 	u8 qualifier;
3424 	unsigned int base;
3425 	union {
3426 		long long s;
3427 		unsigned long long u;
3428 	} val;
3429 	s16 field_width;
3430 	bool is_sign;
3431 
3432 	while (*fmt) {
3433 		/* skip any white space in format */
3434 		/* white space in format matches any amount of
3435 		 * white space, including none, in the input.
3436 		 */
3437 		if (isspace(*fmt)) {
3438 			fmt = skip_spaces(++fmt);
3439 			str = skip_spaces(str);
3440 		}
3441 
3442 		/* anything that is not a conversion must match exactly */
3443 		if (*fmt != '%' && *fmt) {
3444 			if (*fmt++ != *str++)
3445 				break;
3446 			continue;
3447 		}
3448 
3449 		if (!*fmt)
3450 			break;
3451 		++fmt;
3452 
3453 		/* skip this conversion.
3454 		 * advance both strings to next white space
3455 		 */
3456 		if (*fmt == '*') {
3457 			if (!*str)
3458 				break;
3459 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3460 				/* '%*[' not yet supported, invalid format */
3461 				if (*fmt == '[')
3462 					return num;
3463 				fmt++;
3464 			}
3465 			while (!isspace(*str) && *str)
3466 				str++;
3467 			continue;
3468 		}
3469 
3470 		/* get field width */
3471 		field_width = -1;
3472 		if (isdigit(*fmt)) {
3473 			field_width = skip_atoi(&fmt);
3474 			if (field_width <= 0)
3475 				break;
3476 		}
3477 
3478 		/* get conversion qualifier */
3479 		qualifier = -1;
3480 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3481 		    *fmt == 'z') {
3482 			qualifier = *fmt++;
3483 			if (unlikely(qualifier == *fmt)) {
3484 				if (qualifier == 'h') {
3485 					qualifier = 'H';
3486 					fmt++;
3487 				} else if (qualifier == 'l') {
3488 					qualifier = 'L';
3489 					fmt++;
3490 				}
3491 			}
3492 		}
3493 
3494 		if (!*fmt)
3495 			break;
3496 
3497 		if (*fmt == 'n') {
3498 			/* return number of characters read so far */
3499 			*va_arg(args, int *) = str - buf;
3500 			++fmt;
3501 			continue;
3502 		}
3503 
3504 		if (!*str)
3505 			break;
3506 
3507 		base = 10;
3508 		is_sign = false;
3509 
3510 		switch (*fmt++) {
3511 		case 'c':
3512 		{
3513 			char *s = (char *)va_arg(args, char*);
3514 			if (field_width == -1)
3515 				field_width = 1;
3516 			do {
3517 				*s++ = *str++;
3518 			} while (--field_width > 0 && *str);
3519 			num++;
3520 		}
3521 		continue;
3522 		case 's':
3523 		{
3524 			char *s = (char *)va_arg(args, char *);
3525 			if (field_width == -1)
3526 				field_width = SHRT_MAX;
3527 			/* first, skip leading white space in buffer */
3528 			str = skip_spaces(str);
3529 
3530 			/* now copy until next white space */
3531 			while (*str && !isspace(*str) && field_width--)
3532 				*s++ = *str++;
3533 			*s = '\0';
3534 			num++;
3535 		}
3536 		continue;
3537 		/*
3538 		 * Warning: This implementation of the '[' conversion specifier
3539 		 * deviates from its glibc counterpart in the following ways:
3540 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3541 		 *     character
3542 		 * (2) It cannot match the closing bracket ']' itself
3543 		 * (3) A field width is required
3544 		 * (4) '%*[' (discard matching input) is currently not supported
3545 		 *
3546 		 * Example usage:
3547 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3548 		 *		buf1, buf2, buf3);
3549 		 * if (ret < 3)
3550 		 *    // etc..
3551 		 */
3552 		case '[':
3553 		{
3554 			char *s = (char *)va_arg(args, char *);
3555 			DECLARE_BITMAP(set, 256) = {0};
3556 			unsigned int len = 0;
3557 			bool negate = (*fmt == '^');
3558 
3559 			/* field width is required */
3560 			if (field_width == -1)
3561 				return num;
3562 
3563 			if (negate)
3564 				++fmt;
3565 
3566 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3567 				set_bit((u8)*fmt, set);
3568 
3569 			/* no ']' or no character set found */
3570 			if (!*fmt || !len)
3571 				return num;
3572 			++fmt;
3573 
3574 			if (negate) {
3575 				bitmap_complement(set, set, 256);
3576 				/* exclude null '\0' byte */
3577 				clear_bit(0, set);
3578 			}
3579 
3580 			/* match must be non-empty */
3581 			if (!test_bit((u8)*str, set))
3582 				return num;
3583 
3584 			while (test_bit((u8)*str, set) && field_width--)
3585 				*s++ = *str++;
3586 			*s = '\0';
3587 			++num;
3588 		}
3589 		continue;
3590 		case 'o':
3591 			base = 8;
3592 			break;
3593 		case 'x':
3594 		case 'X':
3595 			base = 16;
3596 			break;
3597 		case 'i':
3598 			base = 0;
3599 			fallthrough;
3600 		case 'd':
3601 			is_sign = true;
3602 			fallthrough;
3603 		case 'u':
3604 			break;
3605 		case '%':
3606 			/* looking for '%' in str */
3607 			if (*str++ != '%')
3608 				return num;
3609 			continue;
3610 		default:
3611 			/* invalid format; stop here */
3612 			return num;
3613 		}
3614 
3615 		/* have some sort of integer conversion.
3616 		 * first, skip white space in buffer.
3617 		 */
3618 		str = skip_spaces(str);
3619 
3620 		digit = *str;
3621 		if (is_sign && digit == '-') {
3622 			if (field_width == 1)
3623 				break;
3624 
3625 			digit = *(str + 1);
3626 		}
3627 
3628 		if (!digit
3629 		    || (base == 16 && !isxdigit(digit))
3630 		    || (base == 10 && !isdigit(digit))
3631 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
3632 		    || (base == 0 && !isdigit(digit)))
3633 			break;
3634 
3635 		if (is_sign)
3636 			val.s = simple_strntoll(str,
3637 						field_width >= 0 ? field_width : INT_MAX,
3638 						&next, base);
3639 		else
3640 			val.u = simple_strntoull(str,
3641 						 field_width >= 0 ? field_width : INT_MAX,
3642 						 &next, base);
3643 
3644 		switch (qualifier) {
3645 		case 'H':	/* that's 'hh' in format */
3646 			if (is_sign)
3647 				*va_arg(args, signed char *) = val.s;
3648 			else
3649 				*va_arg(args, unsigned char *) = val.u;
3650 			break;
3651 		case 'h':
3652 			if (is_sign)
3653 				*va_arg(args, short *) = val.s;
3654 			else
3655 				*va_arg(args, unsigned short *) = val.u;
3656 			break;
3657 		case 'l':
3658 			if (is_sign)
3659 				*va_arg(args, long *) = val.s;
3660 			else
3661 				*va_arg(args, unsigned long *) = val.u;
3662 			break;
3663 		case 'L':
3664 			if (is_sign)
3665 				*va_arg(args, long long *) = val.s;
3666 			else
3667 				*va_arg(args, unsigned long long *) = val.u;
3668 			break;
3669 		case 'z':
3670 			*va_arg(args, size_t *) = val.u;
3671 			break;
3672 		default:
3673 			if (is_sign)
3674 				*va_arg(args, int *) = val.s;
3675 			else
3676 				*va_arg(args, unsigned int *) = val.u;
3677 			break;
3678 		}
3679 		num++;
3680 
3681 		if (!next)
3682 			break;
3683 		str = next;
3684 	}
3685 
3686 	return num;
3687 }
3688 EXPORT_SYMBOL(vsscanf);
3689 
3690 /**
3691  * sscanf - Unformat a buffer into a list of arguments
3692  * @buf:	input buffer
3693  * @fmt:	formatting of buffer
3694  * @...:	resulting arguments
3695  */
3696 int sscanf(const char *buf, const char *fmt, ...)
3697 {
3698 	va_list args;
3699 	int i;
3700 
3701 	va_start(args, fmt);
3702 	i = vsscanf(buf, fmt, args);
3703 	va_end(args);
3704 
3705 	return i;
3706 }
3707 EXPORT_SYMBOL(sscanf);
3708