xref: /linux/lib/vsprintf.c (revision 8d4f9145f52e9d1c5e6e86402ef8ca24cadb38f9)
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/sprintf.h>
38 #include <linux/time.h>
39 #include <linux/uuid.h>
40 #include <linux/of.h>
41 #include <net/addrconf.h>
42 #include <linux/siphash.h>
43 #include <linux/compiler.h>
44 #include <linux/property.h>
45 #include <linux/notifier.h>
46 #ifdef CONFIG_BLOCK
47 #include <linux/blkdev.h>
48 #endif
49 
50 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
51 
52 #include <asm/page.h>		/* for PAGE_SIZE */
53 #include <asm/byteorder.h>	/* cpu_to_le16 */
54 #include <asm/unaligned.h>
55 
56 #include <linux/string_helpers.h>
57 #include "kstrtox.h"
58 
59 /* Disable pointer hashing if requested */
60 bool no_hash_pointers __ro_after_init;
61 EXPORT_SYMBOL_GPL(no_hash_pointers);
62 
63 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
64 {
65 	const char *cp;
66 	unsigned long long result = 0ULL;
67 	size_t prefix_chars;
68 	unsigned int rv;
69 
70 	cp = _parse_integer_fixup_radix(startp, &base);
71 	prefix_chars = cp - startp;
72 	if (prefix_chars < max_chars) {
73 		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
74 		/* FIXME */
75 		cp += (rv & ~KSTRTOX_OVERFLOW);
76 	} else {
77 		/* Field too short for prefix + digit, skip over without converting */
78 		cp = startp + max_chars;
79 	}
80 
81 	if (endp)
82 		*endp = (char *)cp;
83 
84 	return result;
85 }
86 
87 /**
88  * simple_strtoull - convert a string to an unsigned long long
89  * @cp: The start of the string
90  * @endp: A pointer to the end of the parsed string will be placed here
91  * @base: The number base to use
92  *
93  * This function has caveats. Please use kstrtoull instead.
94  */
95 noinline
96 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
97 {
98 	return simple_strntoull(cp, INT_MAX, endp, base);
99 }
100 EXPORT_SYMBOL(simple_strtoull);
101 
102 /**
103  * simple_strtoul - convert a string to an unsigned long
104  * @cp: The start of the string
105  * @endp: A pointer to the end of the parsed string will be placed here
106  * @base: The number base to use
107  *
108  * This function has caveats. Please use kstrtoul instead.
109  */
110 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
111 {
112 	return simple_strtoull(cp, endp, base);
113 }
114 EXPORT_SYMBOL(simple_strtoul);
115 
116 /**
117  * simple_strtol - convert a string to a signed long
118  * @cp: The start of the string
119  * @endp: A pointer to the end of the parsed string will be placed here
120  * @base: The number base to use
121  *
122  * This function has caveats. Please use kstrtol instead.
123  */
124 long simple_strtol(const char *cp, char **endp, unsigned int base)
125 {
126 	if (*cp == '-')
127 		return -simple_strtoul(cp + 1, endp, base);
128 
129 	return simple_strtoul(cp, endp, base);
130 }
131 EXPORT_SYMBOL(simple_strtol);
132 
133 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
134 				 unsigned int base)
135 {
136 	/*
137 	 * simple_strntoull() safely handles receiving max_chars==0 in the
138 	 * case cp[0] == '-' && max_chars == 1.
139 	 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
140 	 * and the content of *cp is irrelevant.
141 	 */
142 	if (*cp == '-' && max_chars > 0)
143 		return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
144 
145 	return simple_strntoull(cp, max_chars, endp, base);
146 }
147 
148 /**
149  * simple_strtoll - convert a string to a signed long long
150  * @cp: The start of the string
151  * @endp: A pointer to the end of the parsed string will be placed here
152  * @base: The number base to use
153  *
154  * This function has caveats. Please use kstrtoll instead.
155  */
156 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
157 {
158 	return simple_strntoll(cp, INT_MAX, endp, base);
159 }
160 EXPORT_SYMBOL(simple_strtoll);
161 
162 static noinline_for_stack
163 int skip_atoi(const char **s)
164 {
165 	int i = 0;
166 
167 	do {
168 		i = i*10 + *((*s)++) - '0';
169 	} while (isdigit(**s));
170 
171 	return i;
172 }
173 
174 /*
175  * Decimal conversion is by far the most typical, and is used for
176  * /proc and /sys data. This directly impacts e.g. top performance
177  * with many processes running. We optimize it for speed by emitting
178  * two characters at a time, using a 200 byte lookup table. This
179  * roughly halves the number of multiplications compared to computing
180  * the digits one at a time. Implementation strongly inspired by the
181  * previous version, which in turn used ideas described at
182  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
183  * from the author, Douglas W. Jones).
184  *
185  * It turns out there is precisely one 26 bit fixed-point
186  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
187  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
188  * range happens to be somewhat larger (x <= 1073741898), but that's
189  * irrelevant for our purpose.
190  *
191  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
192  * need a 32x32->64 bit multiply, so we simply use the same constant.
193  *
194  * For dividing a number in the range [100, 10^4-1] by 100, there are
195  * several options. The simplest is (x * 0x147b) >> 19, which is valid
196  * for all x <= 43698.
197  */
198 
199 static const u16 decpair[100] = {
200 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
201 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
202 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
203 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
204 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
205 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
206 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
207 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
208 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
209 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
210 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
211 #undef _
212 };
213 
214 /*
215  * This will print a single '0' even if r == 0, since we would
216  * immediately jump to out_r where two 0s would be written but only
217  * one of them accounted for in buf. This is needed by ip4_string
218  * below. All other callers pass a non-zero value of r.
219 */
220 static noinline_for_stack
221 char *put_dec_trunc8(char *buf, unsigned r)
222 {
223 	unsigned q;
224 
225 	/* 1 <= r < 10^8 */
226 	if (r < 100)
227 		goto out_r;
228 
229 	/* 100 <= r < 10^8 */
230 	q = (r * (u64)0x28f5c29) >> 32;
231 	*((u16 *)buf) = decpair[r - 100*q];
232 	buf += 2;
233 
234 	/* 1 <= q < 10^6 */
235 	if (q < 100)
236 		goto out_q;
237 
238 	/*  100 <= q < 10^6 */
239 	r = (q * (u64)0x28f5c29) >> 32;
240 	*((u16 *)buf) = decpair[q - 100*r];
241 	buf += 2;
242 
243 	/* 1 <= r < 10^4 */
244 	if (r < 100)
245 		goto out_r;
246 
247 	/* 100 <= r < 10^4 */
248 	q = (r * 0x147b) >> 19;
249 	*((u16 *)buf) = decpair[r - 100*q];
250 	buf += 2;
251 out_q:
252 	/* 1 <= q < 100 */
253 	r = q;
254 out_r:
255 	/* 1 <= r < 100 */
256 	*((u16 *)buf) = decpair[r];
257 	buf += r < 10 ? 1 : 2;
258 	return buf;
259 }
260 
261 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
262 static noinline_for_stack
263 char *put_dec_full8(char *buf, unsigned r)
264 {
265 	unsigned q;
266 
267 	/* 0 <= r < 10^8 */
268 	q = (r * (u64)0x28f5c29) >> 32;
269 	*((u16 *)buf) = decpair[r - 100*q];
270 	buf += 2;
271 
272 	/* 0 <= q < 10^6 */
273 	r = (q * (u64)0x28f5c29) >> 32;
274 	*((u16 *)buf) = decpair[q - 100*r];
275 	buf += 2;
276 
277 	/* 0 <= r < 10^4 */
278 	q = (r * 0x147b) >> 19;
279 	*((u16 *)buf) = decpair[r - 100*q];
280 	buf += 2;
281 
282 	/* 0 <= q < 100 */
283 	*((u16 *)buf) = decpair[q];
284 	buf += 2;
285 	return buf;
286 }
287 
288 static noinline_for_stack
289 char *put_dec(char *buf, unsigned long long n)
290 {
291 	if (n >= 100*1000*1000)
292 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
293 	/* 1 <= n <= 1.6e11 */
294 	if (n >= 100*1000*1000)
295 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
296 	/* 1 <= n < 1e8 */
297 	return put_dec_trunc8(buf, n);
298 }
299 
300 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
301 
302 static void
303 put_dec_full4(char *buf, unsigned r)
304 {
305 	unsigned q;
306 
307 	/* 0 <= r < 10^4 */
308 	q = (r * 0x147b) >> 19;
309 	*((u16 *)buf) = decpair[r - 100*q];
310 	buf += 2;
311 	/* 0 <= q < 100 */
312 	*((u16 *)buf) = decpair[q];
313 }
314 
315 /*
316  * Call put_dec_full4 on x % 10000, return x / 10000.
317  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
318  * holds for all x < 1,128,869,999.  The largest value this
319  * helper will ever be asked to convert is 1,125,520,955.
320  * (second call in the put_dec code, assuming n is all-ones).
321  */
322 static noinline_for_stack
323 unsigned put_dec_helper4(char *buf, unsigned x)
324 {
325         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
326 
327         put_dec_full4(buf, x - q * 10000);
328         return q;
329 }
330 
331 /* Based on code by Douglas W. Jones found at
332  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
333  * (with permission from the author).
334  * Performs no 64-bit division and hence should be fast on 32-bit machines.
335  */
336 static
337 char *put_dec(char *buf, unsigned long long n)
338 {
339 	uint32_t d3, d2, d1, q, h;
340 
341 	if (n < 100*1000*1000)
342 		return put_dec_trunc8(buf, n);
343 
344 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
345 	h   = (n >> 32);
346 	d2  = (h      ) & 0xffff;
347 	d3  = (h >> 16); /* implicit "& 0xffff" */
348 
349 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
350 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
351 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
352 	q = put_dec_helper4(buf, q);
353 
354 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
355 	q = put_dec_helper4(buf+4, q);
356 
357 	q += 4749 * d3 + 42 * d2;
358 	q = put_dec_helper4(buf+8, q);
359 
360 	q += 281 * d3;
361 	buf += 12;
362 	if (q)
363 		buf = put_dec_trunc8(buf, q);
364 	else while (buf[-1] == '0')
365 		--buf;
366 
367 	return buf;
368 }
369 
370 #endif
371 
372 /*
373  * Convert passed number to decimal string.
374  * Returns the length of string.  On buffer overflow, returns 0.
375  *
376  * If speed is not important, use snprintf(). It's easy to read the code.
377  */
378 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
379 {
380 	/* put_dec requires 2-byte alignment of the buffer. */
381 	char tmp[sizeof(num) * 3] __aligned(2);
382 	int idx, len;
383 
384 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
385 	if (num <= 9) {
386 		tmp[0] = '0' + num;
387 		len = 1;
388 	} else {
389 		len = put_dec(tmp, num) - tmp;
390 	}
391 
392 	if (len > size || width > size)
393 		return 0;
394 
395 	if (width > len) {
396 		width = width - len;
397 		for (idx = 0; idx < width; idx++)
398 			buf[idx] = ' ';
399 	} else {
400 		width = 0;
401 	}
402 
403 	for (idx = 0; idx < len; ++idx)
404 		buf[idx + width] = tmp[len - idx - 1];
405 
406 	return len + width;
407 }
408 
409 #define SIGN	1		/* unsigned/signed, must be 1 */
410 #define LEFT	2		/* left justified */
411 #define PLUS	4		/* show plus */
412 #define SPACE	8		/* space if plus */
413 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
414 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
415 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
416 
417 static_assert(SIGN == 1);
418 static_assert(ZEROPAD == ('0' - ' '));
419 static_assert(SMALL == ('a' ^ 'A'));
420 
421 enum format_type {
422 	FORMAT_TYPE_NONE, /* Just a string part */
423 	FORMAT_TYPE_WIDTH,
424 	FORMAT_TYPE_PRECISION,
425 	FORMAT_TYPE_CHAR,
426 	FORMAT_TYPE_STR,
427 	FORMAT_TYPE_PTR,
428 	FORMAT_TYPE_PERCENT_CHAR,
429 	FORMAT_TYPE_INVALID,
430 	FORMAT_TYPE_LONG_LONG,
431 	FORMAT_TYPE_ULONG,
432 	FORMAT_TYPE_LONG,
433 	FORMAT_TYPE_UBYTE,
434 	FORMAT_TYPE_BYTE,
435 	FORMAT_TYPE_USHORT,
436 	FORMAT_TYPE_SHORT,
437 	FORMAT_TYPE_UINT,
438 	FORMAT_TYPE_INT,
439 	FORMAT_TYPE_SIZE_T,
440 	FORMAT_TYPE_PTRDIFF
441 };
442 
443 struct printf_spec {
444 	unsigned int	type:8;		/* format_type enum */
445 	signed int	field_width:24;	/* width of output field */
446 	unsigned int	flags:8;	/* flags to number() */
447 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
448 	signed int	precision:16;	/* # of digits/chars */
449 } __packed;
450 static_assert(sizeof(struct printf_spec) == 8);
451 
452 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
453 #define PRECISION_MAX ((1 << 15) - 1)
454 
455 static noinline_for_stack
456 char *number(char *buf, char *end, unsigned long long num,
457 	     struct printf_spec spec)
458 {
459 	/* put_dec requires 2-byte alignment of the buffer. */
460 	char tmp[3 * sizeof(num)] __aligned(2);
461 	char sign;
462 	char locase;
463 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
464 	int i;
465 	bool is_zero = num == 0LL;
466 	int field_width = spec.field_width;
467 	int precision = spec.precision;
468 
469 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
470 	 * produces same digits or (maybe lowercased) letters */
471 	locase = (spec.flags & SMALL);
472 	if (spec.flags & LEFT)
473 		spec.flags &= ~ZEROPAD;
474 	sign = 0;
475 	if (spec.flags & SIGN) {
476 		if ((signed long long)num < 0) {
477 			sign = '-';
478 			num = -(signed long long)num;
479 			field_width--;
480 		} else if (spec.flags & PLUS) {
481 			sign = '+';
482 			field_width--;
483 		} else if (spec.flags & SPACE) {
484 			sign = ' ';
485 			field_width--;
486 		}
487 	}
488 	if (need_pfx) {
489 		if (spec.base == 16)
490 			field_width -= 2;
491 		else if (!is_zero)
492 			field_width--;
493 	}
494 
495 	/* generate full string in tmp[], in reverse order */
496 	i = 0;
497 	if (num < spec.base)
498 		tmp[i++] = hex_asc_upper[num] | locase;
499 	else if (spec.base != 10) { /* 8 or 16 */
500 		int mask = spec.base - 1;
501 		int shift = 3;
502 
503 		if (spec.base == 16)
504 			shift = 4;
505 		do {
506 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
507 			num >>= shift;
508 		} while (num);
509 	} else { /* base 10 */
510 		i = put_dec(tmp, num) - tmp;
511 	}
512 
513 	/* printing 100 using %2d gives "100", not "00" */
514 	if (i > precision)
515 		precision = i;
516 	/* leading space padding */
517 	field_width -= precision;
518 	if (!(spec.flags & (ZEROPAD | LEFT))) {
519 		while (--field_width >= 0) {
520 			if (buf < end)
521 				*buf = ' ';
522 			++buf;
523 		}
524 	}
525 	/* sign */
526 	if (sign) {
527 		if (buf < end)
528 			*buf = sign;
529 		++buf;
530 	}
531 	/* "0x" / "0" prefix */
532 	if (need_pfx) {
533 		if (spec.base == 16 || !is_zero) {
534 			if (buf < end)
535 				*buf = '0';
536 			++buf;
537 		}
538 		if (spec.base == 16) {
539 			if (buf < end)
540 				*buf = ('X' | locase);
541 			++buf;
542 		}
543 	}
544 	/* zero or space padding */
545 	if (!(spec.flags & LEFT)) {
546 		char c = ' ' + (spec.flags & ZEROPAD);
547 
548 		while (--field_width >= 0) {
549 			if (buf < end)
550 				*buf = c;
551 			++buf;
552 		}
553 	}
554 	/* hmm even more zero padding? */
555 	while (i <= --precision) {
556 		if (buf < end)
557 			*buf = '0';
558 		++buf;
559 	}
560 	/* actual digits of result */
561 	while (--i >= 0) {
562 		if (buf < end)
563 			*buf = tmp[i];
564 		++buf;
565 	}
566 	/* trailing space padding */
567 	while (--field_width >= 0) {
568 		if (buf < end)
569 			*buf = ' ';
570 		++buf;
571 	}
572 
573 	return buf;
574 }
575 
576 static noinline_for_stack
577 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
578 {
579 	struct printf_spec spec;
580 
581 	spec.type = FORMAT_TYPE_PTR;
582 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
583 	spec.flags = SPECIAL | SMALL | ZEROPAD;
584 	spec.base = 16;
585 	spec.precision = -1;
586 
587 	return number(buf, end, num, spec);
588 }
589 
590 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
591 {
592 	size_t size;
593 	if (buf >= end)	/* nowhere to put anything */
594 		return;
595 	size = end - buf;
596 	if (size <= spaces) {
597 		memset(buf, ' ', size);
598 		return;
599 	}
600 	if (len) {
601 		if (len > size - spaces)
602 			len = size - spaces;
603 		memmove(buf + spaces, buf, len);
604 	}
605 	memset(buf, ' ', spaces);
606 }
607 
608 /*
609  * Handle field width padding for a string.
610  * @buf: current buffer position
611  * @n: length of string
612  * @end: end of output buffer
613  * @spec: for field width and flags
614  * Returns: new buffer position after padding.
615  */
616 static noinline_for_stack
617 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
618 {
619 	unsigned spaces;
620 
621 	if (likely(n >= spec.field_width))
622 		return buf;
623 	/* we want to pad the sucker */
624 	spaces = spec.field_width - n;
625 	if (!(spec.flags & LEFT)) {
626 		move_right(buf - n, end, n, spaces);
627 		return buf + spaces;
628 	}
629 	while (spaces--) {
630 		if (buf < end)
631 			*buf = ' ';
632 		++buf;
633 	}
634 	return buf;
635 }
636 
637 /* Handle string from a well known address. */
638 static char *string_nocheck(char *buf, char *end, const char *s,
639 			    struct printf_spec spec)
640 {
641 	int len = 0;
642 	int lim = spec.precision;
643 
644 	while (lim--) {
645 		char c = *s++;
646 		if (!c)
647 			break;
648 		if (buf < end)
649 			*buf = c;
650 		++buf;
651 		++len;
652 	}
653 	return widen_string(buf, len, end, spec);
654 }
655 
656 static char *err_ptr(char *buf, char *end, void *ptr,
657 		     struct printf_spec spec)
658 {
659 	int err = PTR_ERR(ptr);
660 	const char *sym = errname(err);
661 
662 	if (sym)
663 		return string_nocheck(buf, end, sym, spec);
664 
665 	/*
666 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
667 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
668 	 * printing it as its decimal representation.
669 	 */
670 	spec.flags |= SIGN;
671 	spec.base = 10;
672 	return number(buf, end, err, spec);
673 }
674 
675 /* Be careful: error messages must fit into the given buffer. */
676 static char *error_string(char *buf, char *end, const char *s,
677 			  struct printf_spec spec)
678 {
679 	/*
680 	 * Hard limit to avoid a completely insane messages. It actually
681 	 * works pretty well because most error messages are in
682 	 * the many pointer format modifiers.
683 	 */
684 	if (spec.precision == -1)
685 		spec.precision = 2 * sizeof(void *);
686 
687 	return string_nocheck(buf, end, s, spec);
688 }
689 
690 /*
691  * Do not call any complex external code here. Nested printk()/vsprintf()
692  * might cause infinite loops. Failures might break printk() and would
693  * be hard to debug.
694  */
695 static const char *check_pointer_msg(const void *ptr)
696 {
697 	if (!ptr)
698 		return "(null)";
699 
700 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
701 		return "(efault)";
702 
703 	return NULL;
704 }
705 
706 static int check_pointer(char **buf, char *end, const void *ptr,
707 			 struct printf_spec spec)
708 {
709 	const char *err_msg;
710 
711 	err_msg = check_pointer_msg(ptr);
712 	if (err_msg) {
713 		*buf = error_string(*buf, end, err_msg, spec);
714 		return -EFAULT;
715 	}
716 
717 	return 0;
718 }
719 
720 static noinline_for_stack
721 char *string(char *buf, char *end, const char *s,
722 	     struct printf_spec spec)
723 {
724 	if (check_pointer(&buf, end, s, spec))
725 		return buf;
726 
727 	return string_nocheck(buf, end, s, spec);
728 }
729 
730 static char *pointer_string(char *buf, char *end,
731 			    const void *ptr,
732 			    struct printf_spec spec)
733 {
734 	spec.base = 16;
735 	spec.flags |= SMALL;
736 	if (spec.field_width == -1) {
737 		spec.field_width = 2 * sizeof(ptr);
738 		spec.flags |= ZEROPAD;
739 	}
740 
741 	return number(buf, end, (unsigned long int)ptr, spec);
742 }
743 
744 /* Make pointers available for printing early in the boot sequence. */
745 static int debug_boot_weak_hash __ro_after_init;
746 
747 static int __init debug_boot_weak_hash_enable(char *str)
748 {
749 	debug_boot_weak_hash = 1;
750 	pr_info("debug_boot_weak_hash enabled\n");
751 	return 0;
752 }
753 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
754 
755 static bool filled_random_ptr_key __read_mostly;
756 static siphash_key_t ptr_key __read_mostly;
757 
758 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
759 {
760 	get_random_bytes(&ptr_key, sizeof(ptr_key));
761 
762 	/* Pairs with smp_rmb() before reading ptr_key. */
763 	smp_wmb();
764 	WRITE_ONCE(filled_random_ptr_key, true);
765 	return NOTIFY_DONE;
766 }
767 
768 static int __init vsprintf_init_hashval(void)
769 {
770 	static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
771 	execute_with_initialized_rng(&fill_ptr_key_nb);
772 	return 0;
773 }
774 subsys_initcall(vsprintf_init_hashval)
775 
776 /* Maps a pointer to a 32 bit unique identifier. */
777 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
778 {
779 	unsigned long hashval;
780 
781 	if (!READ_ONCE(filled_random_ptr_key))
782 		return -EBUSY;
783 
784 	/* Pairs with smp_wmb() after writing ptr_key. */
785 	smp_rmb();
786 
787 #ifdef CONFIG_64BIT
788 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
789 	/*
790 	 * Mask off the first 32 bits, this makes explicit that we have
791 	 * modified the address (and 32 bits is plenty for a unique ID).
792 	 */
793 	hashval = hashval & 0xffffffff;
794 #else
795 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
796 #endif
797 	*hashval_out = hashval;
798 	return 0;
799 }
800 
801 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
802 {
803 	return __ptr_to_hashval(ptr, hashval_out);
804 }
805 
806 static char *ptr_to_id(char *buf, char *end, const void *ptr,
807 		       struct printf_spec spec)
808 {
809 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
810 	unsigned long hashval;
811 	int ret;
812 
813 	/*
814 	 * Print the real pointer value for NULL and error pointers,
815 	 * as they are not actual addresses.
816 	 */
817 	if (IS_ERR_OR_NULL(ptr))
818 		return pointer_string(buf, end, ptr, spec);
819 
820 	/* When debugging early boot use non-cryptographically secure hash. */
821 	if (unlikely(debug_boot_weak_hash)) {
822 		hashval = hash_long((unsigned long)ptr, 32);
823 		return pointer_string(buf, end, (const void *)hashval, spec);
824 	}
825 
826 	ret = __ptr_to_hashval(ptr, &hashval);
827 	if (ret) {
828 		spec.field_width = 2 * sizeof(ptr);
829 		/* string length must be less than default_width */
830 		return error_string(buf, end, str, spec);
831 	}
832 
833 	return pointer_string(buf, end, (const void *)hashval, spec);
834 }
835 
836 static char *default_pointer(char *buf, char *end, const void *ptr,
837 			     struct printf_spec spec)
838 {
839 	/*
840 	 * default is to _not_ leak addresses, so hash before printing,
841 	 * unless no_hash_pointers is specified on the command line.
842 	 */
843 	if (unlikely(no_hash_pointers))
844 		return pointer_string(buf, end, ptr, spec);
845 
846 	return ptr_to_id(buf, end, ptr, spec);
847 }
848 
849 int kptr_restrict __read_mostly;
850 
851 static noinline_for_stack
852 char *restricted_pointer(char *buf, char *end, const void *ptr,
853 			 struct printf_spec spec)
854 {
855 	switch (kptr_restrict) {
856 	case 0:
857 		/* Handle as %p, hash and do _not_ leak addresses. */
858 		return default_pointer(buf, end, ptr, spec);
859 	case 1: {
860 		const struct cred *cred;
861 
862 		/*
863 		 * kptr_restrict==1 cannot be used in IRQ context
864 		 * because its test for CAP_SYSLOG would be meaningless.
865 		 */
866 		if (in_hardirq() || in_serving_softirq() || in_nmi()) {
867 			if (spec.field_width == -1)
868 				spec.field_width = 2 * sizeof(ptr);
869 			return error_string(buf, end, "pK-error", spec);
870 		}
871 
872 		/*
873 		 * Only print the real pointer value if the current
874 		 * process has CAP_SYSLOG and is running with the
875 		 * same credentials it started with. This is because
876 		 * access to files is checked at open() time, but %pK
877 		 * checks permission at read() time. We don't want to
878 		 * leak pointer values if a binary opens a file using
879 		 * %pK and then elevates privileges before reading it.
880 		 */
881 		cred = current_cred();
882 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
883 		    !uid_eq(cred->euid, cred->uid) ||
884 		    !gid_eq(cred->egid, cred->gid))
885 			ptr = NULL;
886 		break;
887 	}
888 	case 2:
889 	default:
890 		/* Always print 0's for %pK */
891 		ptr = NULL;
892 		break;
893 	}
894 
895 	return pointer_string(buf, end, ptr, spec);
896 }
897 
898 static noinline_for_stack
899 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
900 		  const char *fmt)
901 {
902 	const char *array[4], *s;
903 	const struct dentry *p;
904 	int depth;
905 	int i, n;
906 
907 	switch (fmt[1]) {
908 		case '2': case '3': case '4':
909 			depth = fmt[1] - '0';
910 			break;
911 		default:
912 			depth = 1;
913 	}
914 
915 	rcu_read_lock();
916 	for (i = 0; i < depth; i++, d = p) {
917 		if (check_pointer(&buf, end, d, spec)) {
918 			rcu_read_unlock();
919 			return buf;
920 		}
921 
922 		p = READ_ONCE(d->d_parent);
923 		array[i] = READ_ONCE(d->d_name.name);
924 		if (p == d) {
925 			if (i)
926 				array[i] = "";
927 			i++;
928 			break;
929 		}
930 	}
931 	s = array[--i];
932 	for (n = 0; n != spec.precision; n++, buf++) {
933 		char c = *s++;
934 		if (!c) {
935 			if (!i)
936 				break;
937 			c = '/';
938 			s = array[--i];
939 		}
940 		if (buf < end)
941 			*buf = c;
942 	}
943 	rcu_read_unlock();
944 	return widen_string(buf, n, end, spec);
945 }
946 
947 static noinline_for_stack
948 char *file_dentry_name(char *buf, char *end, const struct file *f,
949 			struct printf_spec spec, const char *fmt)
950 {
951 	if (check_pointer(&buf, end, f, spec))
952 		return buf;
953 
954 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
955 }
956 #ifdef CONFIG_BLOCK
957 static noinline_for_stack
958 char *bdev_name(char *buf, char *end, struct block_device *bdev,
959 		struct printf_spec spec, const char *fmt)
960 {
961 	struct gendisk *hd;
962 
963 	if (check_pointer(&buf, end, bdev, spec))
964 		return buf;
965 
966 	hd = bdev->bd_disk;
967 	buf = string(buf, end, hd->disk_name, spec);
968 	if (bdev->bd_partno) {
969 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
970 			if (buf < end)
971 				*buf = 'p';
972 			buf++;
973 		}
974 		buf = number(buf, end, bdev->bd_partno, spec);
975 	}
976 	return buf;
977 }
978 #endif
979 
980 static noinline_for_stack
981 char *symbol_string(char *buf, char *end, void *ptr,
982 		    struct printf_spec spec, const char *fmt)
983 {
984 	unsigned long value;
985 #ifdef CONFIG_KALLSYMS
986 	char sym[KSYM_SYMBOL_LEN];
987 #endif
988 
989 	if (fmt[1] == 'R')
990 		ptr = __builtin_extract_return_addr(ptr);
991 	value = (unsigned long)ptr;
992 
993 #ifdef CONFIG_KALLSYMS
994 	if (*fmt == 'B' && fmt[1] == 'b')
995 		sprint_backtrace_build_id(sym, value);
996 	else if (*fmt == 'B')
997 		sprint_backtrace(sym, value);
998 	else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
999 		sprint_symbol_build_id(sym, value);
1000 	else if (*fmt != 's')
1001 		sprint_symbol(sym, value);
1002 	else
1003 		sprint_symbol_no_offset(sym, value);
1004 
1005 	return string_nocheck(buf, end, sym, spec);
1006 #else
1007 	return special_hex_number(buf, end, value, sizeof(void *));
1008 #endif
1009 }
1010 
1011 static const struct printf_spec default_str_spec = {
1012 	.field_width = -1,
1013 	.precision = -1,
1014 };
1015 
1016 static const struct printf_spec default_flag_spec = {
1017 	.base = 16,
1018 	.precision = -1,
1019 	.flags = SPECIAL | SMALL,
1020 };
1021 
1022 static const struct printf_spec default_dec_spec = {
1023 	.base = 10,
1024 	.precision = -1,
1025 };
1026 
1027 static const struct printf_spec default_dec02_spec = {
1028 	.base = 10,
1029 	.field_width = 2,
1030 	.precision = -1,
1031 	.flags = ZEROPAD,
1032 };
1033 
1034 static const struct printf_spec default_dec04_spec = {
1035 	.base = 10,
1036 	.field_width = 4,
1037 	.precision = -1,
1038 	.flags = ZEROPAD,
1039 };
1040 
1041 static noinline_for_stack
1042 char *resource_string(char *buf, char *end, struct resource *res,
1043 		      struct printf_spec spec, const char *fmt)
1044 {
1045 #ifndef IO_RSRC_PRINTK_SIZE
1046 #define IO_RSRC_PRINTK_SIZE	6
1047 #endif
1048 
1049 #ifndef MEM_RSRC_PRINTK_SIZE
1050 #define MEM_RSRC_PRINTK_SIZE	10
1051 #endif
1052 	static const struct printf_spec io_spec = {
1053 		.base = 16,
1054 		.field_width = IO_RSRC_PRINTK_SIZE,
1055 		.precision = -1,
1056 		.flags = SPECIAL | SMALL | ZEROPAD,
1057 	};
1058 	static const struct printf_spec mem_spec = {
1059 		.base = 16,
1060 		.field_width = MEM_RSRC_PRINTK_SIZE,
1061 		.precision = -1,
1062 		.flags = SPECIAL | SMALL | ZEROPAD,
1063 	};
1064 	static const struct printf_spec bus_spec = {
1065 		.base = 16,
1066 		.field_width = 2,
1067 		.precision = -1,
1068 		.flags = SMALL | ZEROPAD,
1069 	};
1070 	static const struct printf_spec str_spec = {
1071 		.field_width = -1,
1072 		.precision = 10,
1073 		.flags = LEFT,
1074 	};
1075 
1076 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1077 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1078 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1079 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1080 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1081 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1082 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1083 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1084 
1085 	char *p = sym, *pend = sym + sizeof(sym);
1086 	int decode = (fmt[0] == 'R') ? 1 : 0;
1087 	const struct printf_spec *specp;
1088 
1089 	if (check_pointer(&buf, end, res, spec))
1090 		return buf;
1091 
1092 	*p++ = '[';
1093 	if (res->flags & IORESOURCE_IO) {
1094 		p = string_nocheck(p, pend, "io  ", str_spec);
1095 		specp = &io_spec;
1096 	} else if (res->flags & IORESOURCE_MEM) {
1097 		p = string_nocheck(p, pend, "mem ", str_spec);
1098 		specp = &mem_spec;
1099 	} else if (res->flags & IORESOURCE_IRQ) {
1100 		p = string_nocheck(p, pend, "irq ", str_spec);
1101 		specp = &default_dec_spec;
1102 	} else if (res->flags & IORESOURCE_DMA) {
1103 		p = string_nocheck(p, pend, "dma ", str_spec);
1104 		specp = &default_dec_spec;
1105 	} else if (res->flags & IORESOURCE_BUS) {
1106 		p = string_nocheck(p, pend, "bus ", str_spec);
1107 		specp = &bus_spec;
1108 	} else {
1109 		p = string_nocheck(p, pend, "??? ", str_spec);
1110 		specp = &mem_spec;
1111 		decode = 0;
1112 	}
1113 	if (decode && res->flags & IORESOURCE_UNSET) {
1114 		p = string_nocheck(p, pend, "size ", str_spec);
1115 		p = number(p, pend, resource_size(res), *specp);
1116 	} else {
1117 		p = number(p, pend, res->start, *specp);
1118 		if (res->start != res->end) {
1119 			*p++ = '-';
1120 			p = number(p, pend, res->end, *specp);
1121 		}
1122 	}
1123 	if (decode) {
1124 		if (res->flags & IORESOURCE_MEM_64)
1125 			p = string_nocheck(p, pend, " 64bit", str_spec);
1126 		if (res->flags & IORESOURCE_PREFETCH)
1127 			p = string_nocheck(p, pend, " pref", str_spec);
1128 		if (res->flags & IORESOURCE_WINDOW)
1129 			p = string_nocheck(p, pend, " window", str_spec);
1130 		if (res->flags & IORESOURCE_DISABLED)
1131 			p = string_nocheck(p, pend, " disabled", str_spec);
1132 	} else {
1133 		p = string_nocheck(p, pend, " flags ", str_spec);
1134 		p = number(p, pend, res->flags, default_flag_spec);
1135 	}
1136 	*p++ = ']';
1137 	*p = '\0';
1138 
1139 	return string_nocheck(buf, end, sym, spec);
1140 }
1141 
1142 static noinline_for_stack
1143 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1144 		 const char *fmt)
1145 {
1146 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1147 				   negative value, fallback to the default */
1148 	char separator;
1149 
1150 	if (spec.field_width == 0)
1151 		/* nothing to print */
1152 		return buf;
1153 
1154 	if (check_pointer(&buf, end, addr, spec))
1155 		return buf;
1156 
1157 	switch (fmt[1]) {
1158 	case 'C':
1159 		separator = ':';
1160 		break;
1161 	case 'D':
1162 		separator = '-';
1163 		break;
1164 	case 'N':
1165 		separator = 0;
1166 		break;
1167 	default:
1168 		separator = ' ';
1169 		break;
1170 	}
1171 
1172 	if (spec.field_width > 0)
1173 		len = min_t(int, spec.field_width, 64);
1174 
1175 	for (i = 0; i < len; ++i) {
1176 		if (buf < end)
1177 			*buf = hex_asc_hi(addr[i]);
1178 		++buf;
1179 		if (buf < end)
1180 			*buf = hex_asc_lo(addr[i]);
1181 		++buf;
1182 
1183 		if (separator && i != len - 1) {
1184 			if (buf < end)
1185 				*buf = separator;
1186 			++buf;
1187 		}
1188 	}
1189 
1190 	return buf;
1191 }
1192 
1193 static noinline_for_stack
1194 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1195 		    struct printf_spec spec, const char *fmt)
1196 {
1197 	const int CHUNKSZ = 32;
1198 	int nr_bits = max_t(int, spec.field_width, 0);
1199 	int i, chunksz;
1200 	bool first = true;
1201 
1202 	if (check_pointer(&buf, end, bitmap, spec))
1203 		return buf;
1204 
1205 	/* reused to print numbers */
1206 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1207 
1208 	chunksz = nr_bits & (CHUNKSZ - 1);
1209 	if (chunksz == 0)
1210 		chunksz = CHUNKSZ;
1211 
1212 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1213 	for (; i >= 0; i -= CHUNKSZ) {
1214 		u32 chunkmask, val;
1215 		int word, bit;
1216 
1217 		chunkmask = ((1ULL << chunksz) - 1);
1218 		word = i / BITS_PER_LONG;
1219 		bit = i % BITS_PER_LONG;
1220 		val = (bitmap[word] >> bit) & chunkmask;
1221 
1222 		if (!first) {
1223 			if (buf < end)
1224 				*buf = ',';
1225 			buf++;
1226 		}
1227 		first = false;
1228 
1229 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1230 		buf = number(buf, end, val, spec);
1231 
1232 		chunksz = CHUNKSZ;
1233 	}
1234 	return buf;
1235 }
1236 
1237 static noinline_for_stack
1238 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1239 			 struct printf_spec spec, const char *fmt)
1240 {
1241 	int nr_bits = max_t(int, spec.field_width, 0);
1242 	bool first = true;
1243 	int rbot, rtop;
1244 
1245 	if (check_pointer(&buf, end, bitmap, spec))
1246 		return buf;
1247 
1248 	for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1249 		if (!first) {
1250 			if (buf < end)
1251 				*buf = ',';
1252 			buf++;
1253 		}
1254 		first = false;
1255 
1256 		buf = number(buf, end, rbot, default_dec_spec);
1257 		if (rtop == rbot + 1)
1258 			continue;
1259 
1260 		if (buf < end)
1261 			*buf = '-';
1262 		buf = number(++buf, end, rtop - 1, default_dec_spec);
1263 	}
1264 	return buf;
1265 }
1266 
1267 static noinline_for_stack
1268 char *mac_address_string(char *buf, char *end, u8 *addr,
1269 			 struct printf_spec spec, const char *fmt)
1270 {
1271 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1272 	char *p = mac_addr;
1273 	int i;
1274 	char separator;
1275 	bool reversed = false;
1276 
1277 	if (check_pointer(&buf, end, addr, spec))
1278 		return buf;
1279 
1280 	switch (fmt[1]) {
1281 	case 'F':
1282 		separator = '-';
1283 		break;
1284 
1285 	case 'R':
1286 		reversed = true;
1287 		fallthrough;
1288 
1289 	default:
1290 		separator = ':';
1291 		break;
1292 	}
1293 
1294 	for (i = 0; i < 6; i++) {
1295 		if (reversed)
1296 			p = hex_byte_pack(p, addr[5 - i]);
1297 		else
1298 			p = hex_byte_pack(p, addr[i]);
1299 
1300 		if (fmt[0] == 'M' && i != 5)
1301 			*p++ = separator;
1302 	}
1303 	*p = '\0';
1304 
1305 	return string_nocheck(buf, end, mac_addr, spec);
1306 }
1307 
1308 static noinline_for_stack
1309 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1310 {
1311 	int i;
1312 	bool leading_zeros = (fmt[0] == 'i');
1313 	int index;
1314 	int step;
1315 
1316 	switch (fmt[2]) {
1317 	case 'h':
1318 #ifdef __BIG_ENDIAN
1319 		index = 0;
1320 		step = 1;
1321 #else
1322 		index = 3;
1323 		step = -1;
1324 #endif
1325 		break;
1326 	case 'l':
1327 		index = 3;
1328 		step = -1;
1329 		break;
1330 	case 'n':
1331 	case 'b':
1332 	default:
1333 		index = 0;
1334 		step = 1;
1335 		break;
1336 	}
1337 	for (i = 0; i < 4; i++) {
1338 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1339 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1340 		if (leading_zeros) {
1341 			if (digits < 3)
1342 				*p++ = '0';
1343 			if (digits < 2)
1344 				*p++ = '0';
1345 		}
1346 		/* reverse the digits in the quad */
1347 		while (digits--)
1348 			*p++ = temp[digits];
1349 		if (i < 3)
1350 			*p++ = '.';
1351 		index += step;
1352 	}
1353 	*p = '\0';
1354 
1355 	return p;
1356 }
1357 
1358 static noinline_for_stack
1359 char *ip6_compressed_string(char *p, const char *addr)
1360 {
1361 	int i, j, range;
1362 	unsigned char zerolength[8];
1363 	int longest = 1;
1364 	int colonpos = -1;
1365 	u16 word;
1366 	u8 hi, lo;
1367 	bool needcolon = false;
1368 	bool useIPv4;
1369 	struct in6_addr in6;
1370 
1371 	memcpy(&in6, addr, sizeof(struct in6_addr));
1372 
1373 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1374 
1375 	memset(zerolength, 0, sizeof(zerolength));
1376 
1377 	if (useIPv4)
1378 		range = 6;
1379 	else
1380 		range = 8;
1381 
1382 	/* find position of longest 0 run */
1383 	for (i = 0; i < range; i++) {
1384 		for (j = i; j < range; j++) {
1385 			if (in6.s6_addr16[j] != 0)
1386 				break;
1387 			zerolength[i]++;
1388 		}
1389 	}
1390 	for (i = 0; i < range; i++) {
1391 		if (zerolength[i] > longest) {
1392 			longest = zerolength[i];
1393 			colonpos = i;
1394 		}
1395 	}
1396 	if (longest == 1)		/* don't compress a single 0 */
1397 		colonpos = -1;
1398 
1399 	/* emit address */
1400 	for (i = 0; i < range; i++) {
1401 		if (i == colonpos) {
1402 			if (needcolon || i == 0)
1403 				*p++ = ':';
1404 			*p++ = ':';
1405 			needcolon = false;
1406 			i += longest - 1;
1407 			continue;
1408 		}
1409 		if (needcolon) {
1410 			*p++ = ':';
1411 			needcolon = false;
1412 		}
1413 		/* hex u16 without leading 0s */
1414 		word = ntohs(in6.s6_addr16[i]);
1415 		hi = word >> 8;
1416 		lo = word & 0xff;
1417 		if (hi) {
1418 			if (hi > 0x0f)
1419 				p = hex_byte_pack(p, hi);
1420 			else
1421 				*p++ = hex_asc_lo(hi);
1422 			p = hex_byte_pack(p, lo);
1423 		}
1424 		else if (lo > 0x0f)
1425 			p = hex_byte_pack(p, lo);
1426 		else
1427 			*p++ = hex_asc_lo(lo);
1428 		needcolon = true;
1429 	}
1430 
1431 	if (useIPv4) {
1432 		if (needcolon)
1433 			*p++ = ':';
1434 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1435 	}
1436 	*p = '\0';
1437 
1438 	return p;
1439 }
1440 
1441 static noinline_for_stack
1442 char *ip6_string(char *p, const char *addr, const char *fmt)
1443 {
1444 	int i;
1445 
1446 	for (i = 0; i < 8; i++) {
1447 		p = hex_byte_pack(p, *addr++);
1448 		p = hex_byte_pack(p, *addr++);
1449 		if (fmt[0] == 'I' && i != 7)
1450 			*p++ = ':';
1451 	}
1452 	*p = '\0';
1453 
1454 	return p;
1455 }
1456 
1457 static noinline_for_stack
1458 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1459 		      struct printf_spec spec, const char *fmt)
1460 {
1461 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1462 
1463 	if (fmt[0] == 'I' && fmt[2] == 'c')
1464 		ip6_compressed_string(ip6_addr, addr);
1465 	else
1466 		ip6_string(ip6_addr, addr, fmt);
1467 
1468 	return string_nocheck(buf, end, ip6_addr, spec);
1469 }
1470 
1471 static noinline_for_stack
1472 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1473 		      struct printf_spec spec, const char *fmt)
1474 {
1475 	char ip4_addr[sizeof("255.255.255.255")];
1476 
1477 	ip4_string(ip4_addr, addr, fmt);
1478 
1479 	return string_nocheck(buf, end, ip4_addr, spec);
1480 }
1481 
1482 static noinline_for_stack
1483 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1484 			 struct printf_spec spec, const char *fmt)
1485 {
1486 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1487 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1488 		      sizeof(":12345") + sizeof("/123456789") +
1489 		      sizeof("%1234567890")];
1490 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1491 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1492 	char fmt6[2] = { fmt[0], '6' };
1493 	u8 off = 0;
1494 
1495 	fmt++;
1496 	while (isalpha(*++fmt)) {
1497 		switch (*fmt) {
1498 		case 'p':
1499 			have_p = true;
1500 			break;
1501 		case 'f':
1502 			have_f = true;
1503 			break;
1504 		case 's':
1505 			have_s = true;
1506 			break;
1507 		case 'c':
1508 			have_c = true;
1509 			break;
1510 		}
1511 	}
1512 
1513 	if (have_p || have_s || have_f) {
1514 		*p = '[';
1515 		off = 1;
1516 	}
1517 
1518 	if (fmt6[0] == 'I' && have_c)
1519 		p = ip6_compressed_string(ip6_addr + off, addr);
1520 	else
1521 		p = ip6_string(ip6_addr + off, addr, fmt6);
1522 
1523 	if (have_p || have_s || have_f)
1524 		*p++ = ']';
1525 
1526 	if (have_p) {
1527 		*p++ = ':';
1528 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1529 	}
1530 	if (have_f) {
1531 		*p++ = '/';
1532 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1533 					  IPV6_FLOWINFO_MASK), spec);
1534 	}
1535 	if (have_s) {
1536 		*p++ = '%';
1537 		p = number(p, pend, sa->sin6_scope_id, spec);
1538 	}
1539 	*p = '\0';
1540 
1541 	return string_nocheck(buf, end, ip6_addr, spec);
1542 }
1543 
1544 static noinline_for_stack
1545 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1546 			 struct printf_spec spec, const char *fmt)
1547 {
1548 	bool have_p = false;
1549 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1550 	char *pend = ip4_addr + sizeof(ip4_addr);
1551 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1552 	char fmt4[3] = { fmt[0], '4', 0 };
1553 
1554 	fmt++;
1555 	while (isalpha(*++fmt)) {
1556 		switch (*fmt) {
1557 		case 'p':
1558 			have_p = true;
1559 			break;
1560 		case 'h':
1561 		case 'l':
1562 		case 'n':
1563 		case 'b':
1564 			fmt4[2] = *fmt;
1565 			break;
1566 		}
1567 	}
1568 
1569 	p = ip4_string(ip4_addr, addr, fmt4);
1570 	if (have_p) {
1571 		*p++ = ':';
1572 		p = number(p, pend, ntohs(sa->sin_port), spec);
1573 	}
1574 	*p = '\0';
1575 
1576 	return string_nocheck(buf, end, ip4_addr, spec);
1577 }
1578 
1579 static noinline_for_stack
1580 char *ip_addr_string(char *buf, char *end, const void *ptr,
1581 		     struct printf_spec spec, const char *fmt)
1582 {
1583 	char *err_fmt_msg;
1584 
1585 	if (check_pointer(&buf, end, ptr, spec))
1586 		return buf;
1587 
1588 	switch (fmt[1]) {
1589 	case '6':
1590 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1591 	case '4':
1592 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1593 	case 'S': {
1594 		const union {
1595 			struct sockaddr		raw;
1596 			struct sockaddr_in	v4;
1597 			struct sockaddr_in6	v6;
1598 		} *sa = ptr;
1599 
1600 		switch (sa->raw.sa_family) {
1601 		case AF_INET:
1602 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1603 		case AF_INET6:
1604 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1605 		default:
1606 			return error_string(buf, end, "(einval)", spec);
1607 		}}
1608 	}
1609 
1610 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1611 	return error_string(buf, end, err_fmt_msg, spec);
1612 }
1613 
1614 static noinline_for_stack
1615 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1616 		     const char *fmt)
1617 {
1618 	bool found = true;
1619 	int count = 1;
1620 	unsigned int flags = 0;
1621 	int len;
1622 
1623 	if (spec.field_width == 0)
1624 		return buf;				/* nothing to print */
1625 
1626 	if (check_pointer(&buf, end, addr, spec))
1627 		return buf;
1628 
1629 	do {
1630 		switch (fmt[count++]) {
1631 		case 'a':
1632 			flags |= ESCAPE_ANY;
1633 			break;
1634 		case 'c':
1635 			flags |= ESCAPE_SPECIAL;
1636 			break;
1637 		case 'h':
1638 			flags |= ESCAPE_HEX;
1639 			break;
1640 		case 'n':
1641 			flags |= ESCAPE_NULL;
1642 			break;
1643 		case 'o':
1644 			flags |= ESCAPE_OCTAL;
1645 			break;
1646 		case 'p':
1647 			flags |= ESCAPE_NP;
1648 			break;
1649 		case 's':
1650 			flags |= ESCAPE_SPACE;
1651 			break;
1652 		default:
1653 			found = false;
1654 			break;
1655 		}
1656 	} while (found);
1657 
1658 	if (!flags)
1659 		flags = ESCAPE_ANY_NP;
1660 
1661 	len = spec.field_width < 0 ? 1 : spec.field_width;
1662 
1663 	/*
1664 	 * string_escape_mem() writes as many characters as it can to
1665 	 * the given buffer, and returns the total size of the output
1666 	 * had the buffer been big enough.
1667 	 */
1668 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1669 
1670 	return buf;
1671 }
1672 
1673 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1674 		       struct printf_spec spec, const char *fmt)
1675 {
1676 	va_list va;
1677 
1678 	if (check_pointer(&buf, end, va_fmt, spec))
1679 		return buf;
1680 
1681 	va_copy(va, *va_fmt->va);
1682 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1683 	va_end(va);
1684 
1685 	return buf;
1686 }
1687 
1688 static noinline_for_stack
1689 char *uuid_string(char *buf, char *end, const u8 *addr,
1690 		  struct printf_spec spec, const char *fmt)
1691 {
1692 	char uuid[UUID_STRING_LEN + 1];
1693 	char *p = uuid;
1694 	int i;
1695 	const u8 *index = uuid_index;
1696 	bool uc = false;
1697 
1698 	if (check_pointer(&buf, end, addr, spec))
1699 		return buf;
1700 
1701 	switch (*(++fmt)) {
1702 	case 'L':
1703 		uc = true;
1704 		fallthrough;
1705 	case 'l':
1706 		index = guid_index;
1707 		break;
1708 	case 'B':
1709 		uc = true;
1710 		break;
1711 	}
1712 
1713 	for (i = 0; i < 16; i++) {
1714 		if (uc)
1715 			p = hex_byte_pack_upper(p, addr[index[i]]);
1716 		else
1717 			p = hex_byte_pack(p, addr[index[i]]);
1718 		switch (i) {
1719 		case 3:
1720 		case 5:
1721 		case 7:
1722 		case 9:
1723 			*p++ = '-';
1724 			break;
1725 		}
1726 	}
1727 
1728 	*p = 0;
1729 
1730 	return string_nocheck(buf, end, uuid, spec);
1731 }
1732 
1733 static noinline_for_stack
1734 char *netdev_bits(char *buf, char *end, const void *addr,
1735 		  struct printf_spec spec,  const char *fmt)
1736 {
1737 	unsigned long long num;
1738 	int size;
1739 
1740 	if (check_pointer(&buf, end, addr, spec))
1741 		return buf;
1742 
1743 	switch (fmt[1]) {
1744 	case 'F':
1745 		num = *(const netdev_features_t *)addr;
1746 		size = sizeof(netdev_features_t);
1747 		break;
1748 	default:
1749 		return error_string(buf, end, "(%pN?)", spec);
1750 	}
1751 
1752 	return special_hex_number(buf, end, num, size);
1753 }
1754 
1755 static noinline_for_stack
1756 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1757 		    struct printf_spec spec, const char *fmt)
1758 {
1759 	char output[sizeof("0123 little-endian (0x01234567)")];
1760 	char *p = output;
1761 	unsigned int i;
1762 	u32 orig, val;
1763 
1764 	if (fmt[1] != 'c' || fmt[2] != 'c')
1765 		return error_string(buf, end, "(%p4?)", spec);
1766 
1767 	if (check_pointer(&buf, end, fourcc, spec))
1768 		return buf;
1769 
1770 	orig = get_unaligned(fourcc);
1771 	val = orig & ~BIT(31);
1772 
1773 	for (i = 0; i < sizeof(u32); i++) {
1774 		unsigned char c = val >> (i * 8);
1775 
1776 		/* Print non-control ASCII characters as-is, dot otherwise */
1777 		*p++ = isascii(c) && isprint(c) ? c : '.';
1778 	}
1779 
1780 	*p++ = ' ';
1781 	strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1782 	p += strlen(p);
1783 
1784 	*p++ = ' ';
1785 	*p++ = '(';
1786 	p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1787 	*p++ = ')';
1788 	*p = '\0';
1789 
1790 	return string(buf, end, output, spec);
1791 }
1792 
1793 static noinline_for_stack
1794 char *address_val(char *buf, char *end, const void *addr,
1795 		  struct printf_spec spec, const char *fmt)
1796 {
1797 	unsigned long long num;
1798 	int size;
1799 
1800 	if (check_pointer(&buf, end, addr, spec))
1801 		return buf;
1802 
1803 	switch (fmt[1]) {
1804 	case 'd':
1805 		num = *(const dma_addr_t *)addr;
1806 		size = sizeof(dma_addr_t);
1807 		break;
1808 	case 'p':
1809 	default:
1810 		num = *(const phys_addr_t *)addr;
1811 		size = sizeof(phys_addr_t);
1812 		break;
1813 	}
1814 
1815 	return special_hex_number(buf, end, num, size);
1816 }
1817 
1818 static noinline_for_stack
1819 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1820 {
1821 	int year = tm->tm_year + (r ? 0 : 1900);
1822 	int mon = tm->tm_mon + (r ? 0 : 1);
1823 
1824 	buf = number(buf, end, year, default_dec04_spec);
1825 	if (buf < end)
1826 		*buf = '-';
1827 	buf++;
1828 
1829 	buf = number(buf, end, mon, default_dec02_spec);
1830 	if (buf < end)
1831 		*buf = '-';
1832 	buf++;
1833 
1834 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1835 }
1836 
1837 static noinline_for_stack
1838 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1839 {
1840 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1841 	if (buf < end)
1842 		*buf = ':';
1843 	buf++;
1844 
1845 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1846 	if (buf < end)
1847 		*buf = ':';
1848 	buf++;
1849 
1850 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1851 }
1852 
1853 static noinline_for_stack
1854 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1855 	      struct printf_spec spec, const char *fmt)
1856 {
1857 	bool have_t = true, have_d = true;
1858 	bool raw = false, iso8601_separator = true;
1859 	bool found = true;
1860 	int count = 2;
1861 
1862 	if (check_pointer(&buf, end, tm, spec))
1863 		return buf;
1864 
1865 	switch (fmt[count]) {
1866 	case 'd':
1867 		have_t = false;
1868 		count++;
1869 		break;
1870 	case 't':
1871 		have_d = false;
1872 		count++;
1873 		break;
1874 	}
1875 
1876 	do {
1877 		switch (fmt[count++]) {
1878 		case 'r':
1879 			raw = true;
1880 			break;
1881 		case 's':
1882 			iso8601_separator = false;
1883 			break;
1884 		default:
1885 			found = false;
1886 			break;
1887 		}
1888 	} while (found);
1889 
1890 	if (have_d)
1891 		buf = date_str(buf, end, tm, raw);
1892 	if (have_d && have_t) {
1893 		if (buf < end)
1894 			*buf = iso8601_separator ? 'T' : ' ';
1895 		buf++;
1896 	}
1897 	if (have_t)
1898 		buf = time_str(buf, end, tm, raw);
1899 
1900 	return buf;
1901 }
1902 
1903 static noinline_for_stack
1904 char *time64_str(char *buf, char *end, const time64_t time,
1905 		 struct printf_spec spec, const char *fmt)
1906 {
1907 	struct rtc_time rtc_time;
1908 	struct tm tm;
1909 
1910 	time64_to_tm(time, 0, &tm);
1911 
1912 	rtc_time.tm_sec = tm.tm_sec;
1913 	rtc_time.tm_min = tm.tm_min;
1914 	rtc_time.tm_hour = tm.tm_hour;
1915 	rtc_time.tm_mday = tm.tm_mday;
1916 	rtc_time.tm_mon = tm.tm_mon;
1917 	rtc_time.tm_year = tm.tm_year;
1918 	rtc_time.tm_wday = tm.tm_wday;
1919 	rtc_time.tm_yday = tm.tm_yday;
1920 
1921 	rtc_time.tm_isdst = 0;
1922 
1923 	return rtc_str(buf, end, &rtc_time, spec, fmt);
1924 }
1925 
1926 static noinline_for_stack
1927 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1928 		    const char *fmt)
1929 {
1930 	switch (fmt[1]) {
1931 	case 'R':
1932 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1933 	case 'T':
1934 		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1935 	default:
1936 		return error_string(buf, end, "(%pt?)", spec);
1937 	}
1938 }
1939 
1940 static noinline_for_stack
1941 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1942 	    const char *fmt)
1943 {
1944 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1945 		return error_string(buf, end, "(%pC?)", spec);
1946 
1947 	if (check_pointer(&buf, end, clk, spec))
1948 		return buf;
1949 
1950 	switch (fmt[1]) {
1951 	case 'n':
1952 	default:
1953 #ifdef CONFIG_COMMON_CLK
1954 		return string(buf, end, __clk_get_name(clk), spec);
1955 #else
1956 		return ptr_to_id(buf, end, clk, spec);
1957 #endif
1958 	}
1959 }
1960 
1961 static
1962 char *format_flags(char *buf, char *end, unsigned long flags,
1963 					const struct trace_print_flags *names)
1964 {
1965 	unsigned long mask;
1966 
1967 	for ( ; flags && names->name; names++) {
1968 		mask = names->mask;
1969 		if ((flags & mask) != mask)
1970 			continue;
1971 
1972 		buf = string(buf, end, names->name, default_str_spec);
1973 
1974 		flags &= ~mask;
1975 		if (flags) {
1976 			if (buf < end)
1977 				*buf = '|';
1978 			buf++;
1979 		}
1980 	}
1981 
1982 	if (flags)
1983 		buf = number(buf, end, flags, default_flag_spec);
1984 
1985 	return buf;
1986 }
1987 
1988 struct page_flags_fields {
1989 	int width;
1990 	int shift;
1991 	int mask;
1992 	const struct printf_spec *spec;
1993 	const char *name;
1994 };
1995 
1996 static const struct page_flags_fields pff[] = {
1997 	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
1998 	 &default_dec_spec, "section"},
1999 	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2000 	 &default_dec_spec, "node"},
2001 	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2002 	 &default_dec_spec, "zone"},
2003 	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2004 	 &default_flag_spec, "lastcpupid"},
2005 	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2006 	 &default_flag_spec, "kasantag"},
2007 };
2008 
2009 static
2010 char *format_page_flags(char *buf, char *end, unsigned long flags)
2011 {
2012 	unsigned long main_flags = flags & PAGEFLAGS_MASK;
2013 	bool append = false;
2014 	int i;
2015 
2016 	buf = number(buf, end, flags, default_flag_spec);
2017 	if (buf < end)
2018 		*buf = '(';
2019 	buf++;
2020 
2021 	/* Page flags from the main area. */
2022 	if (main_flags) {
2023 		buf = format_flags(buf, end, main_flags, pageflag_names);
2024 		append = true;
2025 	}
2026 
2027 	/* Page flags from the fields area */
2028 	for (i = 0; i < ARRAY_SIZE(pff); i++) {
2029 		/* Skip undefined fields. */
2030 		if (!pff[i].width)
2031 			continue;
2032 
2033 		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2034 		if (append) {
2035 			if (buf < end)
2036 				*buf = '|';
2037 			buf++;
2038 		}
2039 
2040 		buf = string(buf, end, pff[i].name, default_str_spec);
2041 		if (buf < end)
2042 			*buf = '=';
2043 		buf++;
2044 		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2045 			     *pff[i].spec);
2046 
2047 		append = true;
2048 	}
2049 	if (buf < end)
2050 		*buf = ')';
2051 	buf++;
2052 
2053 	return buf;
2054 }
2055 
2056 static
2057 char *format_page_type(char *buf, char *end, unsigned int page_type)
2058 {
2059 	buf = number(buf, end, page_type, default_flag_spec);
2060 
2061 	if (buf < end)
2062 		*buf = '(';
2063 	buf++;
2064 
2065 	if (page_type_has_type(page_type))
2066 		buf = format_flags(buf, end, ~page_type, pagetype_names);
2067 
2068 	if (buf < end)
2069 		*buf = ')';
2070 	buf++;
2071 
2072 	return buf;
2073 }
2074 
2075 static noinline_for_stack
2076 char *flags_string(char *buf, char *end, void *flags_ptr,
2077 		   struct printf_spec spec, const char *fmt)
2078 {
2079 	unsigned long flags;
2080 	const struct trace_print_flags *names;
2081 
2082 	if (check_pointer(&buf, end, flags_ptr, spec))
2083 		return buf;
2084 
2085 	switch (fmt[1]) {
2086 	case 'p':
2087 		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2088 	case 't':
2089 		return format_page_type(buf, end, *(unsigned int *)flags_ptr);
2090 	case 'v':
2091 		flags = *(unsigned long *)flags_ptr;
2092 		names = vmaflag_names;
2093 		break;
2094 	case 'g':
2095 		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2096 		names = gfpflag_names;
2097 		break;
2098 	default:
2099 		return error_string(buf, end, "(%pG?)", spec);
2100 	}
2101 
2102 	return format_flags(buf, end, flags, names);
2103 }
2104 
2105 static noinline_for_stack
2106 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2107 			      char *end)
2108 {
2109 	int depth;
2110 
2111 	/* Loop starting from the root node to the current node. */
2112 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2113 		struct fwnode_handle *__fwnode =
2114 			fwnode_get_nth_parent(fwnode, depth);
2115 
2116 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2117 			     default_str_spec);
2118 		buf = string(buf, end, fwnode_get_name(__fwnode),
2119 			     default_str_spec);
2120 
2121 		fwnode_handle_put(__fwnode);
2122 	}
2123 
2124 	return buf;
2125 }
2126 
2127 static noinline_for_stack
2128 char *device_node_string(char *buf, char *end, struct device_node *dn,
2129 			 struct printf_spec spec, const char *fmt)
2130 {
2131 	char tbuf[sizeof("xxxx") + 1];
2132 	const char *p;
2133 	int ret;
2134 	char *buf_start = buf;
2135 	struct property *prop;
2136 	bool has_mult, pass;
2137 
2138 	struct printf_spec str_spec = spec;
2139 	str_spec.field_width = -1;
2140 
2141 	if (fmt[0] != 'F')
2142 		return error_string(buf, end, "(%pO?)", spec);
2143 
2144 	if (!IS_ENABLED(CONFIG_OF))
2145 		return error_string(buf, end, "(%pOF?)", spec);
2146 
2147 	if (check_pointer(&buf, end, dn, spec))
2148 		return buf;
2149 
2150 	/* simple case without anything any more format specifiers */
2151 	fmt++;
2152 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2153 		fmt = "f";
2154 
2155 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2156 		int precision;
2157 		if (pass) {
2158 			if (buf < end)
2159 				*buf = ':';
2160 			buf++;
2161 		}
2162 
2163 		switch (*fmt) {
2164 		case 'f':	/* full_name */
2165 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2166 						      end);
2167 			break;
2168 		case 'n':	/* name */
2169 			p = fwnode_get_name(of_fwnode_handle(dn));
2170 			precision = str_spec.precision;
2171 			str_spec.precision = strchrnul(p, '@') - p;
2172 			buf = string(buf, end, p, str_spec);
2173 			str_spec.precision = precision;
2174 			break;
2175 		case 'p':	/* phandle */
2176 			buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2177 			break;
2178 		case 'P':	/* path-spec */
2179 			p = fwnode_get_name(of_fwnode_handle(dn));
2180 			if (!p[1])
2181 				p = "/";
2182 			buf = string(buf, end, p, str_spec);
2183 			break;
2184 		case 'F':	/* flags */
2185 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2186 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2187 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2188 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2189 			tbuf[4] = 0;
2190 			buf = string_nocheck(buf, end, tbuf, str_spec);
2191 			break;
2192 		case 'c':	/* major compatible string */
2193 			ret = of_property_read_string(dn, "compatible", &p);
2194 			if (!ret)
2195 				buf = string(buf, end, p, str_spec);
2196 			break;
2197 		case 'C':	/* full compatible string */
2198 			has_mult = false;
2199 			of_property_for_each_string(dn, "compatible", prop, p) {
2200 				if (has_mult)
2201 					buf = string_nocheck(buf, end, ",", str_spec);
2202 				buf = string_nocheck(buf, end, "\"", str_spec);
2203 				buf = string(buf, end, p, str_spec);
2204 				buf = string_nocheck(buf, end, "\"", str_spec);
2205 
2206 				has_mult = true;
2207 			}
2208 			break;
2209 		default:
2210 			break;
2211 		}
2212 	}
2213 
2214 	return widen_string(buf, buf - buf_start, end, spec);
2215 }
2216 
2217 static noinline_for_stack
2218 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2219 		    struct printf_spec spec, const char *fmt)
2220 {
2221 	struct printf_spec str_spec = spec;
2222 	char *buf_start = buf;
2223 
2224 	str_spec.field_width = -1;
2225 
2226 	if (*fmt != 'w')
2227 		return error_string(buf, end, "(%pf?)", spec);
2228 
2229 	if (check_pointer(&buf, end, fwnode, spec))
2230 		return buf;
2231 
2232 	fmt++;
2233 
2234 	switch (*fmt) {
2235 	case 'P':	/* name */
2236 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2237 		break;
2238 	case 'f':	/* full_name */
2239 	default:
2240 		buf = fwnode_full_name_string(fwnode, buf, end);
2241 		break;
2242 	}
2243 
2244 	return widen_string(buf, buf - buf_start, end, spec);
2245 }
2246 
2247 int __init no_hash_pointers_enable(char *str)
2248 {
2249 	if (no_hash_pointers)
2250 		return 0;
2251 
2252 	no_hash_pointers = true;
2253 
2254 	pr_warn("**********************************************************\n");
2255 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2256 	pr_warn("**                                                      **\n");
2257 	pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2258 	pr_warn("** via the console, logs, and other interfaces. This    **\n");
2259 	pr_warn("** might reduce the security of your system.            **\n");
2260 	pr_warn("**                                                      **\n");
2261 	pr_warn("** If you see this message and you are not debugging    **\n");
2262 	pr_warn("** the kernel, report this immediately to your system   **\n");
2263 	pr_warn("** administrator!                                       **\n");
2264 	pr_warn("**                                                      **\n");
2265 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2266 	pr_warn("**********************************************************\n");
2267 
2268 	return 0;
2269 }
2270 early_param("no_hash_pointers", no_hash_pointers_enable);
2271 
2272 /* Used for Rust formatting ('%pA'). */
2273 char *rust_fmt_argument(char *buf, char *end, void *ptr);
2274 
2275 /*
2276  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2277  * by an extra set of alphanumeric characters that are extended format
2278  * specifiers.
2279  *
2280  * Please update scripts/checkpatch.pl when adding/removing conversion
2281  * characters.  (Search for "check for vsprintf extension").
2282  *
2283  * Right now we handle:
2284  *
2285  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2286  * - 's' For symbolic direct pointers (or function descriptors) without offset
2287  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2288  * - 'S[R]b' as above with module build ID (for use in backtraces)
2289  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2290  *	    %ps and %pS. Be careful when re-using these specifiers.
2291  * - 'B' For backtraced symbolic direct pointers with offset
2292  * - 'Bb' as above with module build ID (for use in backtraces)
2293  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2294  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2295  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2296  *       width which must be explicitly specified either as part of the
2297  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2298  *       range-list format instead of hex format
2299  * - 'M' For a 6-byte MAC address, it prints the address in the
2300  *       usual colon-separated hex notation
2301  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2302  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2303  *       with a dash-separated hex notation
2304  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2305  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2306  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2307  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2308  *       [S][pfs]
2309  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2310  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2311  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2312  *       IPv6 omits the colons (01020304...0f)
2313  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2314  *       [S][pfs]
2315  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2316  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2317  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2318  * - 'I[6S]c' for IPv6 addresses printed as specified by
2319  *       https://tools.ietf.org/html/rfc5952
2320  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2321  *                of the following flags (see string_escape_mem() for the
2322  *                details):
2323  *                  a - ESCAPE_ANY
2324  *                  c - ESCAPE_SPECIAL
2325  *                  h - ESCAPE_HEX
2326  *                  n - ESCAPE_NULL
2327  *                  o - ESCAPE_OCTAL
2328  *                  p - ESCAPE_NP
2329  *                  s - ESCAPE_SPACE
2330  *                By default ESCAPE_ANY_NP is used.
2331  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2332  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2333  *       Options for %pU are:
2334  *         b big endian lower case hex (default)
2335  *         B big endian UPPER case hex
2336  *         l little endian lower case hex
2337  *         L little endian UPPER case hex
2338  *           big endian output byte order is:
2339  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2340  *           little endian output byte order is:
2341  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2342  * - 'V' For a struct va_format which contains a format string * and va_list *,
2343  *       call vsnprintf(->format, *->va_list).
2344  *       Implements a "recursive vsnprintf".
2345  *       Do not use this feature without some mechanism to verify the
2346  *       correctness of the format string and va_list arguments.
2347  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2348  *       Use only for procfs, sysfs and similar files, not printk(); please
2349  *       read the documentation (path below) first.
2350  * - 'NF' For a netdev_features_t
2351  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2352  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2353  *            a certain separator (' ' by default):
2354  *              C colon
2355  *              D dash
2356  *              N no separator
2357  *            The maximum supported length is 64 bytes of the input. Consider
2358  *            to use print_hex_dump() for the larger input.
2359  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2360  *           (default assumed to be phys_addr_t, passed by reference)
2361  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2362  * - 'D[234]' Same as 'd' but for a struct file
2363  * - 'g' For block_device name (gendisk + partition number)
2364  * - 't[RT][dt][r][s]' For time and date as represented by:
2365  *      R    struct rtc_time
2366  *      T    time64_t
2367  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2368  *       (legacy clock framework) of the clock
2369  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2370  *        (legacy clock framework) of the clock
2371  * - 'G' For flags to be printed as a collection of symbolic strings that would
2372  *       construct the specific value. Supported flags given by option:
2373  *       p page flags (see struct page) given as pointer to unsigned long
2374  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2375  *       v vma flags (VM_*) given as pointer to unsigned long
2376  * - 'OF[fnpPcCF]'  For a device tree object
2377  *                  Without any optional arguments prints the full_name
2378  *                  f device node full_name
2379  *                  n device node name
2380  *                  p device node phandle
2381  *                  P device node path spec (name + @unit)
2382  *                  F device node flags
2383  *                  c major compatible string
2384  *                  C full compatible string
2385  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2386  *		Without an option prints the full name of the node
2387  *		f full name
2388  *		P node name, including a possible unit address
2389  * - 'x' For printing the address unmodified. Equivalent to "%lx".
2390  *       Please read the documentation (path below) before using!
2391  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2392  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2393  *           or user (u) memory to probe, and:
2394  *              s a string, equivalent to "%s" on direct vsnprintf() use
2395  *
2396  * ** When making changes please also update:
2397  *	Documentation/core-api/printk-formats.rst
2398  *
2399  * Note: The default behaviour (unadorned %p) is to hash the address,
2400  * rendering it useful as a unique identifier.
2401  *
2402  * There is also a '%pA' format specifier, but it is only intended to be used
2403  * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2404  * See rust/kernel/print.rs for details.
2405  */
2406 static noinline_for_stack
2407 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2408 	      struct printf_spec spec)
2409 {
2410 	switch (*fmt) {
2411 	case 'S':
2412 	case 's':
2413 		ptr = dereference_symbol_descriptor(ptr);
2414 		fallthrough;
2415 	case 'B':
2416 		return symbol_string(buf, end, ptr, spec, fmt);
2417 	case 'R':
2418 	case 'r':
2419 		return resource_string(buf, end, ptr, spec, fmt);
2420 	case 'h':
2421 		return hex_string(buf, end, ptr, spec, fmt);
2422 	case 'b':
2423 		switch (fmt[1]) {
2424 		case 'l':
2425 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2426 		default:
2427 			return bitmap_string(buf, end, ptr, spec, fmt);
2428 		}
2429 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2430 	case 'm':			/* Contiguous: 000102030405 */
2431 					/* [mM]F (FDDI) */
2432 					/* [mM]R (Reverse order; Bluetooth) */
2433 		return mac_address_string(buf, end, ptr, spec, fmt);
2434 	case 'I':			/* Formatted IP supported
2435 					 * 4:	1.2.3.4
2436 					 * 6:	0001:0203:...:0708
2437 					 * 6c:	1::708 or 1::1.2.3.4
2438 					 */
2439 	case 'i':			/* Contiguous:
2440 					 * 4:	001.002.003.004
2441 					 * 6:   000102...0f
2442 					 */
2443 		return ip_addr_string(buf, end, ptr, spec, fmt);
2444 	case 'E':
2445 		return escaped_string(buf, end, ptr, spec, fmt);
2446 	case 'U':
2447 		return uuid_string(buf, end, ptr, spec, fmt);
2448 	case 'V':
2449 		return va_format(buf, end, ptr, spec, fmt);
2450 	case 'K':
2451 		return restricted_pointer(buf, end, ptr, spec);
2452 	case 'N':
2453 		return netdev_bits(buf, end, ptr, spec, fmt);
2454 	case '4':
2455 		return fourcc_string(buf, end, ptr, spec, fmt);
2456 	case 'a':
2457 		return address_val(buf, end, ptr, spec, fmt);
2458 	case 'd':
2459 		return dentry_name(buf, end, ptr, spec, fmt);
2460 	case 't':
2461 		return time_and_date(buf, end, ptr, spec, fmt);
2462 	case 'C':
2463 		return clock(buf, end, ptr, spec, fmt);
2464 	case 'D':
2465 		return file_dentry_name(buf, end, ptr, spec, fmt);
2466 #ifdef CONFIG_BLOCK
2467 	case 'g':
2468 		return bdev_name(buf, end, ptr, spec, fmt);
2469 #endif
2470 
2471 	case 'G':
2472 		return flags_string(buf, end, ptr, spec, fmt);
2473 	case 'O':
2474 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2475 	case 'f':
2476 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2477 	case 'A':
2478 		if (!IS_ENABLED(CONFIG_RUST)) {
2479 			WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2480 			return error_string(buf, end, "(%pA?)", spec);
2481 		}
2482 		return rust_fmt_argument(buf, end, ptr);
2483 	case 'x':
2484 		return pointer_string(buf, end, ptr, spec);
2485 	case 'e':
2486 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2487 		if (!IS_ERR(ptr))
2488 			return default_pointer(buf, end, ptr, spec);
2489 		return err_ptr(buf, end, ptr, spec);
2490 	case 'u':
2491 	case 'k':
2492 		switch (fmt[1]) {
2493 		case 's':
2494 			return string(buf, end, ptr, spec);
2495 		default:
2496 			return error_string(buf, end, "(einval)", spec);
2497 		}
2498 	default:
2499 		return default_pointer(buf, end, ptr, spec);
2500 	}
2501 }
2502 
2503 /*
2504  * Helper function to decode printf style format.
2505  * Each call decode a token from the format and return the
2506  * number of characters read (or likely the delta where it wants
2507  * to go on the next call).
2508  * The decoded token is returned through the parameters
2509  *
2510  * 'h', 'l', or 'L' for integer fields
2511  * 'z' support added 23/7/1999 S.H.
2512  * 'z' changed to 'Z' --davidm 1/25/99
2513  * 'Z' changed to 'z' --adobriyan 2017-01-25
2514  * 't' added for ptrdiff_t
2515  *
2516  * @fmt: the format string
2517  * @type of the token returned
2518  * @flags: various flags such as +, -, # tokens..
2519  * @field_width: overwritten width
2520  * @base: base of the number (octal, hex, ...)
2521  * @precision: precision of a number
2522  * @qualifier: qualifier of a number (long, size_t, ...)
2523  */
2524 static noinline_for_stack
2525 int format_decode(const char *fmt, struct printf_spec *spec)
2526 {
2527 	const char *start = fmt;
2528 	char qualifier;
2529 
2530 	/* we finished early by reading the field width */
2531 	if (spec->type == FORMAT_TYPE_WIDTH) {
2532 		if (spec->field_width < 0) {
2533 			spec->field_width = -spec->field_width;
2534 			spec->flags |= LEFT;
2535 		}
2536 		spec->type = FORMAT_TYPE_NONE;
2537 		goto precision;
2538 	}
2539 
2540 	/* we finished early by reading the precision */
2541 	if (spec->type == FORMAT_TYPE_PRECISION) {
2542 		if (spec->precision < 0)
2543 			spec->precision = 0;
2544 
2545 		spec->type = FORMAT_TYPE_NONE;
2546 		goto qualifier;
2547 	}
2548 
2549 	/* By default */
2550 	spec->type = FORMAT_TYPE_NONE;
2551 
2552 	for (; *fmt ; ++fmt) {
2553 		if (*fmt == '%')
2554 			break;
2555 	}
2556 
2557 	/* Return the current non-format string */
2558 	if (fmt != start || !*fmt)
2559 		return fmt - start;
2560 
2561 	/* Process flags */
2562 	spec->flags = 0;
2563 
2564 	while (1) { /* this also skips first '%' */
2565 		bool found = true;
2566 
2567 		++fmt;
2568 
2569 		switch (*fmt) {
2570 		case '-': spec->flags |= LEFT;    break;
2571 		case '+': spec->flags |= PLUS;    break;
2572 		case ' ': spec->flags |= SPACE;   break;
2573 		case '#': spec->flags |= SPECIAL; break;
2574 		case '0': spec->flags |= ZEROPAD; break;
2575 		default:  found = false;
2576 		}
2577 
2578 		if (!found)
2579 			break;
2580 	}
2581 
2582 	/* get field width */
2583 	spec->field_width = -1;
2584 
2585 	if (isdigit(*fmt))
2586 		spec->field_width = skip_atoi(&fmt);
2587 	else if (*fmt == '*') {
2588 		/* it's the next argument */
2589 		spec->type = FORMAT_TYPE_WIDTH;
2590 		return ++fmt - start;
2591 	}
2592 
2593 precision:
2594 	/* get the precision */
2595 	spec->precision = -1;
2596 	if (*fmt == '.') {
2597 		++fmt;
2598 		if (isdigit(*fmt)) {
2599 			spec->precision = skip_atoi(&fmt);
2600 			if (spec->precision < 0)
2601 				spec->precision = 0;
2602 		} else if (*fmt == '*') {
2603 			/* it's the next argument */
2604 			spec->type = FORMAT_TYPE_PRECISION;
2605 			return ++fmt - start;
2606 		}
2607 	}
2608 
2609 qualifier:
2610 	/* get the conversion qualifier */
2611 	qualifier = 0;
2612 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2613 	    *fmt == 'z' || *fmt == 't') {
2614 		qualifier = *fmt++;
2615 		if (unlikely(qualifier == *fmt)) {
2616 			if (qualifier == 'l') {
2617 				qualifier = 'L';
2618 				++fmt;
2619 			} else if (qualifier == 'h') {
2620 				qualifier = 'H';
2621 				++fmt;
2622 			}
2623 		}
2624 	}
2625 
2626 	/* default base */
2627 	spec->base = 10;
2628 	switch (*fmt) {
2629 	case 'c':
2630 		spec->type = FORMAT_TYPE_CHAR;
2631 		return ++fmt - start;
2632 
2633 	case 's':
2634 		spec->type = FORMAT_TYPE_STR;
2635 		return ++fmt - start;
2636 
2637 	case 'p':
2638 		spec->type = FORMAT_TYPE_PTR;
2639 		return ++fmt - start;
2640 
2641 	case '%':
2642 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2643 		return ++fmt - start;
2644 
2645 	/* integer number formats - set up the flags and "break" */
2646 	case 'o':
2647 		spec->base = 8;
2648 		break;
2649 
2650 	case 'x':
2651 		spec->flags |= SMALL;
2652 		fallthrough;
2653 
2654 	case 'X':
2655 		spec->base = 16;
2656 		break;
2657 
2658 	case 'd':
2659 	case 'i':
2660 		spec->flags |= SIGN;
2661 		break;
2662 	case 'u':
2663 		break;
2664 
2665 	case 'n':
2666 		/*
2667 		 * Since %n poses a greater security risk than
2668 		 * utility, treat it as any other invalid or
2669 		 * unsupported format specifier.
2670 		 */
2671 		fallthrough;
2672 
2673 	default:
2674 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2675 		spec->type = FORMAT_TYPE_INVALID;
2676 		return fmt - start;
2677 	}
2678 
2679 	if (qualifier == 'L')
2680 		spec->type = FORMAT_TYPE_LONG_LONG;
2681 	else if (qualifier == 'l') {
2682 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2683 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2684 	} else if (qualifier == 'z') {
2685 		spec->type = FORMAT_TYPE_SIZE_T;
2686 	} else if (qualifier == 't') {
2687 		spec->type = FORMAT_TYPE_PTRDIFF;
2688 	} else if (qualifier == 'H') {
2689 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2690 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2691 	} else if (qualifier == 'h') {
2692 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2693 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2694 	} else {
2695 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2696 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2697 	}
2698 
2699 	return ++fmt - start;
2700 }
2701 
2702 static void
2703 set_field_width(struct printf_spec *spec, int width)
2704 {
2705 	spec->field_width = width;
2706 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2707 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2708 	}
2709 }
2710 
2711 static void
2712 set_precision(struct printf_spec *spec, int prec)
2713 {
2714 	spec->precision = prec;
2715 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2716 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2717 	}
2718 }
2719 
2720 /**
2721  * vsnprintf - Format a string and place it in a buffer
2722  * @buf: The buffer to place the result into
2723  * @size: The size of the buffer, including the trailing null space
2724  * @fmt: The format string to use
2725  * @args: Arguments for the format string
2726  *
2727  * This function generally follows C99 vsnprintf, but has some
2728  * extensions and a few limitations:
2729  *
2730  *  - ``%n`` is unsupported
2731  *  - ``%p*`` is handled by pointer()
2732  *
2733  * See pointer() or Documentation/core-api/printk-formats.rst for more
2734  * extensive description.
2735  *
2736  * **Please update the documentation in both places when making changes**
2737  *
2738  * The return value is the number of characters which would
2739  * be generated for the given input, excluding the trailing
2740  * '\0', as per ISO C99. If you want to have the exact
2741  * number of characters written into @buf as return value
2742  * (not including the trailing '\0'), use vscnprintf(). If the
2743  * return is greater than or equal to @size, the resulting
2744  * string is truncated.
2745  *
2746  * If you're not already dealing with a va_list consider using snprintf().
2747  */
2748 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2749 {
2750 	unsigned long long num;
2751 	char *str, *end;
2752 	struct printf_spec spec = {0};
2753 
2754 	/* Reject out-of-range values early.  Large positive sizes are
2755 	   used for unknown buffer sizes. */
2756 	if (WARN_ON_ONCE(size > INT_MAX))
2757 		return 0;
2758 
2759 	str = buf;
2760 	end = buf + size;
2761 
2762 	/* Make sure end is always >= buf */
2763 	if (end < buf) {
2764 		end = ((void *)-1);
2765 		size = end - buf;
2766 	}
2767 
2768 	while (*fmt) {
2769 		const char *old_fmt = fmt;
2770 		int read = format_decode(fmt, &spec);
2771 
2772 		fmt += read;
2773 
2774 		switch (spec.type) {
2775 		case FORMAT_TYPE_NONE: {
2776 			int copy = read;
2777 			if (str < end) {
2778 				if (copy > end - str)
2779 					copy = end - str;
2780 				memcpy(str, old_fmt, copy);
2781 			}
2782 			str += read;
2783 			break;
2784 		}
2785 
2786 		case FORMAT_TYPE_WIDTH:
2787 			set_field_width(&spec, va_arg(args, int));
2788 			break;
2789 
2790 		case FORMAT_TYPE_PRECISION:
2791 			set_precision(&spec, va_arg(args, int));
2792 			break;
2793 
2794 		case FORMAT_TYPE_CHAR: {
2795 			char c;
2796 
2797 			if (!(spec.flags & LEFT)) {
2798 				while (--spec.field_width > 0) {
2799 					if (str < end)
2800 						*str = ' ';
2801 					++str;
2802 
2803 				}
2804 			}
2805 			c = (unsigned char) va_arg(args, int);
2806 			if (str < end)
2807 				*str = c;
2808 			++str;
2809 			while (--spec.field_width > 0) {
2810 				if (str < end)
2811 					*str = ' ';
2812 				++str;
2813 			}
2814 			break;
2815 		}
2816 
2817 		case FORMAT_TYPE_STR:
2818 			str = string(str, end, va_arg(args, char *), spec);
2819 			break;
2820 
2821 		case FORMAT_TYPE_PTR:
2822 			str = pointer(fmt, str, end, va_arg(args, void *),
2823 				      spec);
2824 			while (isalnum(*fmt))
2825 				fmt++;
2826 			break;
2827 
2828 		case FORMAT_TYPE_PERCENT_CHAR:
2829 			if (str < end)
2830 				*str = '%';
2831 			++str;
2832 			break;
2833 
2834 		case FORMAT_TYPE_INVALID:
2835 			/*
2836 			 * Presumably the arguments passed gcc's type
2837 			 * checking, but there is no safe or sane way
2838 			 * for us to continue parsing the format and
2839 			 * fetching from the va_list; the remaining
2840 			 * specifiers and arguments would be out of
2841 			 * sync.
2842 			 */
2843 			goto out;
2844 
2845 		default:
2846 			switch (spec.type) {
2847 			case FORMAT_TYPE_LONG_LONG:
2848 				num = va_arg(args, long long);
2849 				break;
2850 			case FORMAT_TYPE_ULONG:
2851 				num = va_arg(args, unsigned long);
2852 				break;
2853 			case FORMAT_TYPE_LONG:
2854 				num = va_arg(args, long);
2855 				break;
2856 			case FORMAT_TYPE_SIZE_T:
2857 				if (spec.flags & SIGN)
2858 					num = va_arg(args, ssize_t);
2859 				else
2860 					num = va_arg(args, size_t);
2861 				break;
2862 			case FORMAT_TYPE_PTRDIFF:
2863 				num = va_arg(args, ptrdiff_t);
2864 				break;
2865 			case FORMAT_TYPE_UBYTE:
2866 				num = (unsigned char) va_arg(args, int);
2867 				break;
2868 			case FORMAT_TYPE_BYTE:
2869 				num = (signed char) va_arg(args, int);
2870 				break;
2871 			case FORMAT_TYPE_USHORT:
2872 				num = (unsigned short) va_arg(args, int);
2873 				break;
2874 			case FORMAT_TYPE_SHORT:
2875 				num = (short) va_arg(args, int);
2876 				break;
2877 			case FORMAT_TYPE_INT:
2878 				num = (int) va_arg(args, int);
2879 				break;
2880 			default:
2881 				num = va_arg(args, unsigned int);
2882 			}
2883 
2884 			str = number(str, end, num, spec);
2885 		}
2886 	}
2887 
2888 out:
2889 	if (size > 0) {
2890 		if (str < end)
2891 			*str = '\0';
2892 		else
2893 			end[-1] = '\0';
2894 	}
2895 
2896 	/* the trailing null byte doesn't count towards the total */
2897 	return str-buf;
2898 
2899 }
2900 EXPORT_SYMBOL(vsnprintf);
2901 
2902 /**
2903  * vscnprintf - Format a string and place it in a buffer
2904  * @buf: The buffer to place the result into
2905  * @size: The size of the buffer, including the trailing null space
2906  * @fmt: The format string to use
2907  * @args: Arguments for the format string
2908  *
2909  * The return value is the number of characters which have been written into
2910  * the @buf not including the trailing '\0'. If @size is == 0 the function
2911  * returns 0.
2912  *
2913  * If you're not already dealing with a va_list consider using scnprintf().
2914  *
2915  * See the vsnprintf() documentation for format string extensions over C99.
2916  */
2917 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2918 {
2919 	int i;
2920 
2921 	if (unlikely(!size))
2922 		return 0;
2923 
2924 	i = vsnprintf(buf, size, fmt, args);
2925 
2926 	if (likely(i < size))
2927 		return i;
2928 
2929 	return size - 1;
2930 }
2931 EXPORT_SYMBOL(vscnprintf);
2932 
2933 /**
2934  * snprintf - Format a string and place it in a buffer
2935  * @buf: The buffer to place the result into
2936  * @size: The size of the buffer, including the trailing null space
2937  * @fmt: The format string to use
2938  * @...: Arguments for the format string
2939  *
2940  * The return value is the number of characters which would be
2941  * generated for the given input, excluding the trailing null,
2942  * as per ISO C99.  If the return is greater than or equal to
2943  * @size, the resulting string is truncated.
2944  *
2945  * See the vsnprintf() documentation for format string extensions over C99.
2946  */
2947 int snprintf(char *buf, size_t size, const char *fmt, ...)
2948 {
2949 	va_list args;
2950 	int i;
2951 
2952 	va_start(args, fmt);
2953 	i = vsnprintf(buf, size, fmt, args);
2954 	va_end(args);
2955 
2956 	return i;
2957 }
2958 EXPORT_SYMBOL(snprintf);
2959 
2960 /**
2961  * scnprintf - Format a string and place it in a buffer
2962  * @buf: The buffer to place the result into
2963  * @size: The size of the buffer, including the trailing null space
2964  * @fmt: The format string to use
2965  * @...: Arguments for the format string
2966  *
2967  * The return value is the number of characters written into @buf not including
2968  * the trailing '\0'. If @size is == 0 the function returns 0.
2969  */
2970 
2971 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2972 {
2973 	va_list args;
2974 	int i;
2975 
2976 	va_start(args, fmt);
2977 	i = vscnprintf(buf, size, fmt, args);
2978 	va_end(args);
2979 
2980 	return i;
2981 }
2982 EXPORT_SYMBOL(scnprintf);
2983 
2984 /**
2985  * vsprintf - Format a string and place it in a buffer
2986  * @buf: The buffer to place the result into
2987  * @fmt: The format string to use
2988  * @args: Arguments for the format string
2989  *
2990  * The function returns the number of characters written
2991  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2992  * buffer overflows.
2993  *
2994  * If you're not already dealing with a va_list consider using sprintf().
2995  *
2996  * See the vsnprintf() documentation for format string extensions over C99.
2997  */
2998 int vsprintf(char *buf, const char *fmt, va_list args)
2999 {
3000 	return vsnprintf(buf, INT_MAX, fmt, args);
3001 }
3002 EXPORT_SYMBOL(vsprintf);
3003 
3004 /**
3005  * sprintf - Format a string and place it in a buffer
3006  * @buf: The buffer to place the result into
3007  * @fmt: The format string to use
3008  * @...: Arguments for the format string
3009  *
3010  * The function returns the number of characters written
3011  * into @buf. Use snprintf() or scnprintf() in order to avoid
3012  * buffer overflows.
3013  *
3014  * See the vsnprintf() documentation for format string extensions over C99.
3015  */
3016 int sprintf(char *buf, const char *fmt, ...)
3017 {
3018 	va_list args;
3019 	int i;
3020 
3021 	va_start(args, fmt);
3022 	i = vsnprintf(buf, INT_MAX, fmt, args);
3023 	va_end(args);
3024 
3025 	return i;
3026 }
3027 EXPORT_SYMBOL(sprintf);
3028 
3029 #ifdef CONFIG_BINARY_PRINTF
3030 /*
3031  * bprintf service:
3032  * vbin_printf() - VA arguments to binary data
3033  * bstr_printf() - Binary data to text string
3034  */
3035 
3036 /**
3037  * vbin_printf - Parse a format string and place args' binary value in a buffer
3038  * @bin_buf: The buffer to place args' binary value
3039  * @size: The size of the buffer(by words(32bits), not characters)
3040  * @fmt: The format string to use
3041  * @args: Arguments for the format string
3042  *
3043  * The format follows C99 vsnprintf, except %n is ignored, and its argument
3044  * is skipped.
3045  *
3046  * The return value is the number of words(32bits) which would be generated for
3047  * the given input.
3048  *
3049  * NOTE:
3050  * If the return value is greater than @size, the resulting bin_buf is NOT
3051  * valid for bstr_printf().
3052  */
3053 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3054 {
3055 	struct printf_spec spec = {0};
3056 	char *str, *end;
3057 	int width;
3058 
3059 	str = (char *)bin_buf;
3060 	end = (char *)(bin_buf + size);
3061 
3062 #define save_arg(type)							\
3063 ({									\
3064 	unsigned long long value;					\
3065 	if (sizeof(type) == 8) {					\
3066 		unsigned long long val8;				\
3067 		str = PTR_ALIGN(str, sizeof(u32));			\
3068 		val8 = va_arg(args, unsigned long long);		\
3069 		if (str + sizeof(type) <= end) {			\
3070 			*(u32 *)str = *(u32 *)&val8;			\
3071 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
3072 		}							\
3073 		value = val8;						\
3074 	} else {							\
3075 		unsigned int val4;					\
3076 		str = PTR_ALIGN(str, sizeof(type));			\
3077 		val4 = va_arg(args, int);				\
3078 		if (str + sizeof(type) <= end)				\
3079 			*(typeof(type) *)str = (type)(long)val4;	\
3080 		value = (unsigned long long)val4;			\
3081 	}								\
3082 	str += sizeof(type);						\
3083 	value;								\
3084 })
3085 
3086 	while (*fmt) {
3087 		int read = format_decode(fmt, &spec);
3088 
3089 		fmt += read;
3090 
3091 		switch (spec.type) {
3092 		case FORMAT_TYPE_NONE:
3093 		case FORMAT_TYPE_PERCENT_CHAR:
3094 			break;
3095 		case FORMAT_TYPE_INVALID:
3096 			goto out;
3097 
3098 		case FORMAT_TYPE_WIDTH:
3099 		case FORMAT_TYPE_PRECISION:
3100 			width = (int)save_arg(int);
3101 			/* Pointers may require the width */
3102 			if (*fmt == 'p')
3103 				set_field_width(&spec, width);
3104 			break;
3105 
3106 		case FORMAT_TYPE_CHAR:
3107 			save_arg(char);
3108 			break;
3109 
3110 		case FORMAT_TYPE_STR: {
3111 			const char *save_str = va_arg(args, char *);
3112 			const char *err_msg;
3113 			size_t len;
3114 
3115 			err_msg = check_pointer_msg(save_str);
3116 			if (err_msg)
3117 				save_str = err_msg;
3118 
3119 			len = strlen(save_str) + 1;
3120 			if (str + len < end)
3121 				memcpy(str, save_str, len);
3122 			str += len;
3123 			break;
3124 		}
3125 
3126 		case FORMAT_TYPE_PTR:
3127 			/* Dereferenced pointers must be done now */
3128 			switch (*fmt) {
3129 			/* Dereference of functions is still OK */
3130 			case 'S':
3131 			case 's':
3132 			case 'x':
3133 			case 'K':
3134 			case 'e':
3135 				save_arg(void *);
3136 				break;
3137 			default:
3138 				if (!isalnum(*fmt)) {
3139 					save_arg(void *);
3140 					break;
3141 				}
3142 				str = pointer(fmt, str, end, va_arg(args, void *),
3143 					      spec);
3144 				if (str + 1 < end)
3145 					*str++ = '\0';
3146 				else
3147 					end[-1] = '\0'; /* Must be nul terminated */
3148 			}
3149 			/* skip all alphanumeric pointer suffixes */
3150 			while (isalnum(*fmt))
3151 				fmt++;
3152 			break;
3153 
3154 		default:
3155 			switch (spec.type) {
3156 
3157 			case FORMAT_TYPE_LONG_LONG:
3158 				save_arg(long long);
3159 				break;
3160 			case FORMAT_TYPE_ULONG:
3161 			case FORMAT_TYPE_LONG:
3162 				save_arg(unsigned long);
3163 				break;
3164 			case FORMAT_TYPE_SIZE_T:
3165 				save_arg(size_t);
3166 				break;
3167 			case FORMAT_TYPE_PTRDIFF:
3168 				save_arg(ptrdiff_t);
3169 				break;
3170 			case FORMAT_TYPE_UBYTE:
3171 			case FORMAT_TYPE_BYTE:
3172 				save_arg(char);
3173 				break;
3174 			case FORMAT_TYPE_USHORT:
3175 			case FORMAT_TYPE_SHORT:
3176 				save_arg(short);
3177 				break;
3178 			default:
3179 				save_arg(int);
3180 			}
3181 		}
3182 	}
3183 
3184 out:
3185 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3186 #undef save_arg
3187 }
3188 EXPORT_SYMBOL_GPL(vbin_printf);
3189 
3190 /**
3191  * bstr_printf - Format a string from binary arguments and place it in a buffer
3192  * @buf: The buffer to place the result into
3193  * @size: The size of the buffer, including the trailing null space
3194  * @fmt: The format string to use
3195  * @bin_buf: Binary arguments for the format string
3196  *
3197  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3198  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3199  * a binary buffer that generated by vbin_printf.
3200  *
3201  * The format follows C99 vsnprintf, but has some extensions:
3202  *  see vsnprintf comment for details.
3203  *
3204  * The return value is the number of characters which would
3205  * be generated for the given input, excluding the trailing
3206  * '\0', as per ISO C99. If you want to have the exact
3207  * number of characters written into @buf as return value
3208  * (not including the trailing '\0'), use vscnprintf(). If the
3209  * return is greater than or equal to @size, the resulting
3210  * string is truncated.
3211  */
3212 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3213 {
3214 	struct printf_spec spec = {0};
3215 	char *str, *end;
3216 	const char *args = (const char *)bin_buf;
3217 
3218 	if (WARN_ON_ONCE(size > INT_MAX))
3219 		return 0;
3220 
3221 	str = buf;
3222 	end = buf + size;
3223 
3224 #define get_arg(type)							\
3225 ({									\
3226 	typeof(type) value;						\
3227 	if (sizeof(type) == 8) {					\
3228 		args = PTR_ALIGN(args, sizeof(u32));			\
3229 		*(u32 *)&value = *(u32 *)args;				\
3230 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3231 	} else {							\
3232 		args = PTR_ALIGN(args, sizeof(type));			\
3233 		value = *(typeof(type) *)args;				\
3234 	}								\
3235 	args += sizeof(type);						\
3236 	value;								\
3237 })
3238 
3239 	/* Make sure end is always >= buf */
3240 	if (end < buf) {
3241 		end = ((void *)-1);
3242 		size = end - buf;
3243 	}
3244 
3245 	while (*fmt) {
3246 		const char *old_fmt = fmt;
3247 		int read = format_decode(fmt, &spec);
3248 
3249 		fmt += read;
3250 
3251 		switch (spec.type) {
3252 		case FORMAT_TYPE_NONE: {
3253 			int copy = read;
3254 			if (str < end) {
3255 				if (copy > end - str)
3256 					copy = end - str;
3257 				memcpy(str, old_fmt, copy);
3258 			}
3259 			str += read;
3260 			break;
3261 		}
3262 
3263 		case FORMAT_TYPE_WIDTH:
3264 			set_field_width(&spec, get_arg(int));
3265 			break;
3266 
3267 		case FORMAT_TYPE_PRECISION:
3268 			set_precision(&spec, get_arg(int));
3269 			break;
3270 
3271 		case FORMAT_TYPE_CHAR: {
3272 			char c;
3273 
3274 			if (!(spec.flags & LEFT)) {
3275 				while (--spec.field_width > 0) {
3276 					if (str < end)
3277 						*str = ' ';
3278 					++str;
3279 				}
3280 			}
3281 			c = (unsigned char) get_arg(char);
3282 			if (str < end)
3283 				*str = c;
3284 			++str;
3285 			while (--spec.field_width > 0) {
3286 				if (str < end)
3287 					*str = ' ';
3288 				++str;
3289 			}
3290 			break;
3291 		}
3292 
3293 		case FORMAT_TYPE_STR: {
3294 			const char *str_arg = args;
3295 			args += strlen(str_arg) + 1;
3296 			str = string(str, end, (char *)str_arg, spec);
3297 			break;
3298 		}
3299 
3300 		case FORMAT_TYPE_PTR: {
3301 			bool process = false;
3302 			int copy, len;
3303 			/* Non function dereferences were already done */
3304 			switch (*fmt) {
3305 			case 'S':
3306 			case 's':
3307 			case 'x':
3308 			case 'K':
3309 			case 'e':
3310 				process = true;
3311 				break;
3312 			default:
3313 				if (!isalnum(*fmt)) {
3314 					process = true;
3315 					break;
3316 				}
3317 				/* Pointer dereference was already processed */
3318 				if (str < end) {
3319 					len = copy = strlen(args);
3320 					if (copy > end - str)
3321 						copy = end - str;
3322 					memcpy(str, args, copy);
3323 					str += len;
3324 					args += len + 1;
3325 				}
3326 			}
3327 			if (process)
3328 				str = pointer(fmt, str, end, get_arg(void *), spec);
3329 
3330 			while (isalnum(*fmt))
3331 				fmt++;
3332 			break;
3333 		}
3334 
3335 		case FORMAT_TYPE_PERCENT_CHAR:
3336 			if (str < end)
3337 				*str = '%';
3338 			++str;
3339 			break;
3340 
3341 		case FORMAT_TYPE_INVALID:
3342 			goto out;
3343 
3344 		default: {
3345 			unsigned long long num;
3346 
3347 			switch (spec.type) {
3348 
3349 			case FORMAT_TYPE_LONG_LONG:
3350 				num = get_arg(long long);
3351 				break;
3352 			case FORMAT_TYPE_ULONG:
3353 			case FORMAT_TYPE_LONG:
3354 				num = get_arg(unsigned long);
3355 				break;
3356 			case FORMAT_TYPE_SIZE_T:
3357 				num = get_arg(size_t);
3358 				break;
3359 			case FORMAT_TYPE_PTRDIFF:
3360 				num = get_arg(ptrdiff_t);
3361 				break;
3362 			case FORMAT_TYPE_UBYTE:
3363 				num = get_arg(unsigned char);
3364 				break;
3365 			case FORMAT_TYPE_BYTE:
3366 				num = get_arg(signed char);
3367 				break;
3368 			case FORMAT_TYPE_USHORT:
3369 				num = get_arg(unsigned short);
3370 				break;
3371 			case FORMAT_TYPE_SHORT:
3372 				num = get_arg(short);
3373 				break;
3374 			case FORMAT_TYPE_UINT:
3375 				num = get_arg(unsigned int);
3376 				break;
3377 			default:
3378 				num = get_arg(int);
3379 			}
3380 
3381 			str = number(str, end, num, spec);
3382 		} /* default: */
3383 		} /* switch(spec.type) */
3384 	} /* while(*fmt) */
3385 
3386 out:
3387 	if (size > 0) {
3388 		if (str < end)
3389 			*str = '\0';
3390 		else
3391 			end[-1] = '\0';
3392 	}
3393 
3394 #undef get_arg
3395 
3396 	/* the trailing null byte doesn't count towards the total */
3397 	return str - buf;
3398 }
3399 EXPORT_SYMBOL_GPL(bstr_printf);
3400 
3401 /**
3402  * bprintf - Parse a format string and place args' binary value in a buffer
3403  * @bin_buf: The buffer to place args' binary value
3404  * @size: The size of the buffer(by words(32bits), not characters)
3405  * @fmt: The format string to use
3406  * @...: Arguments for the format string
3407  *
3408  * The function returns the number of words(u32) written
3409  * into @bin_buf.
3410  */
3411 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3412 {
3413 	va_list args;
3414 	int ret;
3415 
3416 	va_start(args, fmt);
3417 	ret = vbin_printf(bin_buf, size, fmt, args);
3418 	va_end(args);
3419 
3420 	return ret;
3421 }
3422 EXPORT_SYMBOL_GPL(bprintf);
3423 
3424 #endif /* CONFIG_BINARY_PRINTF */
3425 
3426 /**
3427  * vsscanf - Unformat a buffer into a list of arguments
3428  * @buf:	input buffer
3429  * @fmt:	format of buffer
3430  * @args:	arguments
3431  */
3432 int vsscanf(const char *buf, const char *fmt, va_list args)
3433 {
3434 	const char *str = buf;
3435 	char *next;
3436 	char digit;
3437 	int num = 0;
3438 	u8 qualifier;
3439 	unsigned int base;
3440 	union {
3441 		long long s;
3442 		unsigned long long u;
3443 	} val;
3444 	s16 field_width;
3445 	bool is_sign;
3446 
3447 	while (*fmt) {
3448 		/* skip any white space in format */
3449 		/* white space in format matches any amount of
3450 		 * white space, including none, in the input.
3451 		 */
3452 		if (isspace(*fmt)) {
3453 			fmt = skip_spaces(++fmt);
3454 			str = skip_spaces(str);
3455 		}
3456 
3457 		/* anything that is not a conversion must match exactly */
3458 		if (*fmt != '%' && *fmt) {
3459 			if (*fmt++ != *str++)
3460 				break;
3461 			continue;
3462 		}
3463 
3464 		if (!*fmt)
3465 			break;
3466 		++fmt;
3467 
3468 		/* skip this conversion.
3469 		 * advance both strings to next white space
3470 		 */
3471 		if (*fmt == '*') {
3472 			if (!*str)
3473 				break;
3474 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3475 				/* '%*[' not yet supported, invalid format */
3476 				if (*fmt == '[')
3477 					return num;
3478 				fmt++;
3479 			}
3480 			while (!isspace(*str) && *str)
3481 				str++;
3482 			continue;
3483 		}
3484 
3485 		/* get field width */
3486 		field_width = -1;
3487 		if (isdigit(*fmt)) {
3488 			field_width = skip_atoi(&fmt);
3489 			if (field_width <= 0)
3490 				break;
3491 		}
3492 
3493 		/* get conversion qualifier */
3494 		qualifier = -1;
3495 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3496 		    *fmt == 'z') {
3497 			qualifier = *fmt++;
3498 			if (unlikely(qualifier == *fmt)) {
3499 				if (qualifier == 'h') {
3500 					qualifier = 'H';
3501 					fmt++;
3502 				} else if (qualifier == 'l') {
3503 					qualifier = 'L';
3504 					fmt++;
3505 				}
3506 			}
3507 		}
3508 
3509 		if (!*fmt)
3510 			break;
3511 
3512 		if (*fmt == 'n') {
3513 			/* return number of characters read so far */
3514 			*va_arg(args, int *) = str - buf;
3515 			++fmt;
3516 			continue;
3517 		}
3518 
3519 		if (!*str)
3520 			break;
3521 
3522 		base = 10;
3523 		is_sign = false;
3524 
3525 		switch (*fmt++) {
3526 		case 'c':
3527 		{
3528 			char *s = (char *)va_arg(args, char*);
3529 			if (field_width == -1)
3530 				field_width = 1;
3531 			do {
3532 				*s++ = *str++;
3533 			} while (--field_width > 0 && *str);
3534 			num++;
3535 		}
3536 		continue;
3537 		case 's':
3538 		{
3539 			char *s = (char *)va_arg(args, char *);
3540 			if (field_width == -1)
3541 				field_width = SHRT_MAX;
3542 			/* first, skip leading white space in buffer */
3543 			str = skip_spaces(str);
3544 
3545 			/* now copy until next white space */
3546 			while (*str && !isspace(*str) && field_width--)
3547 				*s++ = *str++;
3548 			*s = '\0';
3549 			num++;
3550 		}
3551 		continue;
3552 		/*
3553 		 * Warning: This implementation of the '[' conversion specifier
3554 		 * deviates from its glibc counterpart in the following ways:
3555 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3556 		 *     character
3557 		 * (2) It cannot match the closing bracket ']' itself
3558 		 * (3) A field width is required
3559 		 * (4) '%*[' (discard matching input) is currently not supported
3560 		 *
3561 		 * Example usage:
3562 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3563 		 *		buf1, buf2, buf3);
3564 		 * if (ret < 3)
3565 		 *    // etc..
3566 		 */
3567 		case '[':
3568 		{
3569 			char *s = (char *)va_arg(args, char *);
3570 			DECLARE_BITMAP(set, 256) = {0};
3571 			unsigned int len = 0;
3572 			bool negate = (*fmt == '^');
3573 
3574 			/* field width is required */
3575 			if (field_width == -1)
3576 				return num;
3577 
3578 			if (negate)
3579 				++fmt;
3580 
3581 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3582 				__set_bit((u8)*fmt, set);
3583 
3584 			/* no ']' or no character set found */
3585 			if (!*fmt || !len)
3586 				return num;
3587 			++fmt;
3588 
3589 			if (negate) {
3590 				bitmap_complement(set, set, 256);
3591 				/* exclude null '\0' byte */
3592 				__clear_bit(0, set);
3593 			}
3594 
3595 			/* match must be non-empty */
3596 			if (!test_bit((u8)*str, set))
3597 				return num;
3598 
3599 			while (test_bit((u8)*str, set) && field_width--)
3600 				*s++ = *str++;
3601 			*s = '\0';
3602 			++num;
3603 		}
3604 		continue;
3605 		case 'o':
3606 			base = 8;
3607 			break;
3608 		case 'x':
3609 		case 'X':
3610 			base = 16;
3611 			break;
3612 		case 'i':
3613 			base = 0;
3614 			fallthrough;
3615 		case 'd':
3616 			is_sign = true;
3617 			fallthrough;
3618 		case 'u':
3619 			break;
3620 		case '%':
3621 			/* looking for '%' in str */
3622 			if (*str++ != '%')
3623 				return num;
3624 			continue;
3625 		default:
3626 			/* invalid format; stop here */
3627 			return num;
3628 		}
3629 
3630 		/* have some sort of integer conversion.
3631 		 * first, skip white space in buffer.
3632 		 */
3633 		str = skip_spaces(str);
3634 
3635 		digit = *str;
3636 		if (is_sign && digit == '-') {
3637 			if (field_width == 1)
3638 				break;
3639 
3640 			digit = *(str + 1);
3641 		}
3642 
3643 		if (!digit
3644 		    || (base == 16 && !isxdigit(digit))
3645 		    || (base == 10 && !isdigit(digit))
3646 		    || (base == 8 && !isodigit(digit))
3647 		    || (base == 0 && !isdigit(digit)))
3648 			break;
3649 
3650 		if (is_sign)
3651 			val.s = simple_strntoll(str,
3652 						field_width >= 0 ? field_width : INT_MAX,
3653 						&next, base);
3654 		else
3655 			val.u = simple_strntoull(str,
3656 						 field_width >= 0 ? field_width : INT_MAX,
3657 						 &next, base);
3658 
3659 		switch (qualifier) {
3660 		case 'H':	/* that's 'hh' in format */
3661 			if (is_sign)
3662 				*va_arg(args, signed char *) = val.s;
3663 			else
3664 				*va_arg(args, unsigned char *) = val.u;
3665 			break;
3666 		case 'h':
3667 			if (is_sign)
3668 				*va_arg(args, short *) = val.s;
3669 			else
3670 				*va_arg(args, unsigned short *) = val.u;
3671 			break;
3672 		case 'l':
3673 			if (is_sign)
3674 				*va_arg(args, long *) = val.s;
3675 			else
3676 				*va_arg(args, unsigned long *) = val.u;
3677 			break;
3678 		case 'L':
3679 			if (is_sign)
3680 				*va_arg(args, long long *) = val.s;
3681 			else
3682 				*va_arg(args, unsigned long long *) = val.u;
3683 			break;
3684 		case 'z':
3685 			*va_arg(args, size_t *) = val.u;
3686 			break;
3687 		default:
3688 			if (is_sign)
3689 				*va_arg(args, int *) = val.s;
3690 			else
3691 				*va_arg(args, unsigned int *) = val.u;
3692 			break;
3693 		}
3694 		num++;
3695 
3696 		if (!next)
3697 			break;
3698 		str = next;
3699 	}
3700 
3701 	return num;
3702 }
3703 EXPORT_SYMBOL(vsscanf);
3704 
3705 /**
3706  * sscanf - Unformat a buffer into a list of arguments
3707  * @buf:	input buffer
3708  * @fmt:	formatting of buffer
3709  * @...:	resulting arguments
3710  */
3711 int sscanf(const char *buf, const char *fmt, ...)
3712 {
3713 	va_list args;
3714 	int i;
3715 
3716 	va_start(args, fmt);
3717 	i = vsscanf(buf, fmt, args);
3718 	va_end(args);
3719 
3720 	return i;
3721 }
3722 EXPORT_SYMBOL(sscanf);
3723