xref: /linux/lib/vsprintf.c (revision e0c1b49f5b674cca7b10549c53b3791d0bbc90a8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/lib/vsprintf.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  */
7 
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10  * Wirzenius wrote this portably, Torvalds fucked it up :-)
11  */
12 
13 /*
14  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15  * - changed to provide snprintf and vsnprintf functions
16  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17  * - scnprintf and vscnprintf
18  */
19 
20 #include <linux/stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/time.h>
38 #include <linux/uuid.h>
39 #include <linux/of.h>
40 #include <net/addrconf.h>
41 #include <linux/siphash.h>
42 #include <linux/compiler.h>
43 #include <linux/property.h>
44 #ifdef CONFIG_BLOCK
45 #include <linux/blkdev.h>
46 #endif
47 
48 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
49 
50 #include <asm/page.h>		/* for PAGE_SIZE */
51 #include <asm/byteorder.h>	/* cpu_to_le16 */
52 
53 #include <linux/string_helpers.h>
54 #include "kstrtox.h"
55 
56 static unsigned long long simple_strntoull(const char *startp, size_t max_chars,
57 					   char **endp, unsigned int base)
58 {
59 	const char *cp;
60 	unsigned long long result = 0ULL;
61 	size_t prefix_chars;
62 	unsigned int rv;
63 
64 	cp = _parse_integer_fixup_radix(startp, &base);
65 	prefix_chars = cp - startp;
66 	if (prefix_chars < max_chars) {
67 		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
68 		/* FIXME */
69 		cp += (rv & ~KSTRTOX_OVERFLOW);
70 	} else {
71 		/* Field too short for prefix + digit, skip over without converting */
72 		cp = startp + max_chars;
73 	}
74 
75 	if (endp)
76 		*endp = (char *)cp;
77 
78 	return result;
79 }
80 
81 /**
82  * simple_strtoull - convert a string to an unsigned long long
83  * @cp: The start of the string
84  * @endp: A pointer to the end of the parsed string will be placed here
85  * @base: The number base to use
86  *
87  * This function has caveats. Please use kstrtoull instead.
88  */
89 noinline
90 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
91 {
92 	return simple_strntoull(cp, INT_MAX, endp, base);
93 }
94 EXPORT_SYMBOL(simple_strtoull);
95 
96 /**
97  * simple_strtoul - convert a string to an unsigned long
98  * @cp: The start of the string
99  * @endp: A pointer to the end of the parsed string will be placed here
100  * @base: The number base to use
101  *
102  * This function has caveats. Please use kstrtoul instead.
103  */
104 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
105 {
106 	return simple_strtoull(cp, endp, base);
107 }
108 EXPORT_SYMBOL(simple_strtoul);
109 
110 /**
111  * simple_strtol - convert a string to a signed long
112  * @cp: The start of the string
113  * @endp: A pointer to the end of the parsed string will be placed here
114  * @base: The number base to use
115  *
116  * This function has caveats. Please use kstrtol instead.
117  */
118 long simple_strtol(const char *cp, char **endp, unsigned int base)
119 {
120 	if (*cp == '-')
121 		return -simple_strtoul(cp + 1, endp, base);
122 
123 	return simple_strtoul(cp, endp, base);
124 }
125 EXPORT_SYMBOL(simple_strtol);
126 
127 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
128 				 unsigned int base)
129 {
130 	/*
131 	 * simple_strntoull() safely handles receiving max_chars==0 in the
132 	 * case cp[0] == '-' && max_chars == 1.
133 	 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
134 	 * and the content of *cp is irrelevant.
135 	 */
136 	if (*cp == '-' && max_chars > 0)
137 		return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
138 
139 	return simple_strntoull(cp, max_chars, endp, base);
140 }
141 
142 /**
143  * simple_strtoll - convert a string to a signed long long
144  * @cp: The start of the string
145  * @endp: A pointer to the end of the parsed string will be placed here
146  * @base: The number base to use
147  *
148  * This function has caveats. Please use kstrtoll instead.
149  */
150 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
151 {
152 	return simple_strntoll(cp, INT_MAX, endp, base);
153 }
154 EXPORT_SYMBOL(simple_strtoll);
155 
156 static noinline_for_stack
157 int skip_atoi(const char **s)
158 {
159 	int i = 0;
160 
161 	do {
162 		i = i*10 + *((*s)++) - '0';
163 	} while (isdigit(**s));
164 
165 	return i;
166 }
167 
168 /*
169  * Decimal conversion is by far the most typical, and is used for
170  * /proc and /sys data. This directly impacts e.g. top performance
171  * with many processes running. We optimize it for speed by emitting
172  * two characters at a time, using a 200 byte lookup table. This
173  * roughly halves the number of multiplications compared to computing
174  * the digits one at a time. Implementation strongly inspired by the
175  * previous version, which in turn used ideas described at
176  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
177  * from the author, Douglas W. Jones).
178  *
179  * It turns out there is precisely one 26 bit fixed-point
180  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
181  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
182  * range happens to be somewhat larger (x <= 1073741898), but that's
183  * irrelevant for our purpose.
184  *
185  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
186  * need a 32x32->64 bit multiply, so we simply use the same constant.
187  *
188  * For dividing a number in the range [100, 10^4-1] by 100, there are
189  * several options. The simplest is (x * 0x147b) >> 19, which is valid
190  * for all x <= 43698.
191  */
192 
193 static const u16 decpair[100] = {
194 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
195 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
196 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
197 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
198 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
199 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
200 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
201 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
202 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
203 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
204 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
205 #undef _
206 };
207 
208 /*
209  * This will print a single '0' even if r == 0, since we would
210  * immediately jump to out_r where two 0s would be written but only
211  * one of them accounted for in buf. This is needed by ip4_string
212  * below. All other callers pass a non-zero value of r.
213 */
214 static noinline_for_stack
215 char *put_dec_trunc8(char *buf, unsigned r)
216 {
217 	unsigned q;
218 
219 	/* 1 <= r < 10^8 */
220 	if (r < 100)
221 		goto out_r;
222 
223 	/* 100 <= r < 10^8 */
224 	q = (r * (u64)0x28f5c29) >> 32;
225 	*((u16 *)buf) = decpair[r - 100*q];
226 	buf += 2;
227 
228 	/* 1 <= q < 10^6 */
229 	if (q < 100)
230 		goto out_q;
231 
232 	/*  100 <= q < 10^6 */
233 	r = (q * (u64)0x28f5c29) >> 32;
234 	*((u16 *)buf) = decpair[q - 100*r];
235 	buf += 2;
236 
237 	/* 1 <= r < 10^4 */
238 	if (r < 100)
239 		goto out_r;
240 
241 	/* 100 <= r < 10^4 */
242 	q = (r * 0x147b) >> 19;
243 	*((u16 *)buf) = decpair[r - 100*q];
244 	buf += 2;
245 out_q:
246 	/* 1 <= q < 100 */
247 	r = q;
248 out_r:
249 	/* 1 <= r < 100 */
250 	*((u16 *)buf) = decpair[r];
251 	buf += r < 10 ? 1 : 2;
252 	return buf;
253 }
254 
255 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
256 static noinline_for_stack
257 char *put_dec_full8(char *buf, unsigned r)
258 {
259 	unsigned q;
260 
261 	/* 0 <= r < 10^8 */
262 	q = (r * (u64)0x28f5c29) >> 32;
263 	*((u16 *)buf) = decpair[r - 100*q];
264 	buf += 2;
265 
266 	/* 0 <= q < 10^6 */
267 	r = (q * (u64)0x28f5c29) >> 32;
268 	*((u16 *)buf) = decpair[q - 100*r];
269 	buf += 2;
270 
271 	/* 0 <= r < 10^4 */
272 	q = (r * 0x147b) >> 19;
273 	*((u16 *)buf) = decpair[r - 100*q];
274 	buf += 2;
275 
276 	/* 0 <= q < 100 */
277 	*((u16 *)buf) = decpair[q];
278 	buf += 2;
279 	return buf;
280 }
281 
282 static noinline_for_stack
283 char *put_dec(char *buf, unsigned long long n)
284 {
285 	if (n >= 100*1000*1000)
286 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
287 	/* 1 <= n <= 1.6e11 */
288 	if (n >= 100*1000*1000)
289 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
290 	/* 1 <= n < 1e8 */
291 	return put_dec_trunc8(buf, n);
292 }
293 
294 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
295 
296 static void
297 put_dec_full4(char *buf, unsigned r)
298 {
299 	unsigned q;
300 
301 	/* 0 <= r < 10^4 */
302 	q = (r * 0x147b) >> 19;
303 	*((u16 *)buf) = decpair[r - 100*q];
304 	buf += 2;
305 	/* 0 <= q < 100 */
306 	*((u16 *)buf) = decpair[q];
307 }
308 
309 /*
310  * Call put_dec_full4 on x % 10000, return x / 10000.
311  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
312  * holds for all x < 1,128,869,999.  The largest value this
313  * helper will ever be asked to convert is 1,125,520,955.
314  * (second call in the put_dec code, assuming n is all-ones).
315  */
316 static noinline_for_stack
317 unsigned put_dec_helper4(char *buf, unsigned x)
318 {
319         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
320 
321         put_dec_full4(buf, x - q * 10000);
322         return q;
323 }
324 
325 /* Based on code by Douglas W. Jones found at
326  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
327  * (with permission from the author).
328  * Performs no 64-bit division and hence should be fast on 32-bit machines.
329  */
330 static
331 char *put_dec(char *buf, unsigned long long n)
332 {
333 	uint32_t d3, d2, d1, q, h;
334 
335 	if (n < 100*1000*1000)
336 		return put_dec_trunc8(buf, n);
337 
338 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
339 	h   = (n >> 32);
340 	d2  = (h      ) & 0xffff;
341 	d3  = (h >> 16); /* implicit "& 0xffff" */
342 
343 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
344 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
345 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
346 	q = put_dec_helper4(buf, q);
347 
348 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
349 	q = put_dec_helper4(buf+4, q);
350 
351 	q += 4749 * d3 + 42 * d2;
352 	q = put_dec_helper4(buf+8, q);
353 
354 	q += 281 * d3;
355 	buf += 12;
356 	if (q)
357 		buf = put_dec_trunc8(buf, q);
358 	else while (buf[-1] == '0')
359 		--buf;
360 
361 	return buf;
362 }
363 
364 #endif
365 
366 /*
367  * Convert passed number to decimal string.
368  * Returns the length of string.  On buffer overflow, returns 0.
369  *
370  * If speed is not important, use snprintf(). It's easy to read the code.
371  */
372 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
373 {
374 	/* put_dec requires 2-byte alignment of the buffer. */
375 	char tmp[sizeof(num) * 3] __aligned(2);
376 	int idx, len;
377 
378 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
379 	if (num <= 9) {
380 		tmp[0] = '0' + num;
381 		len = 1;
382 	} else {
383 		len = put_dec(tmp, num) - tmp;
384 	}
385 
386 	if (len > size || width > size)
387 		return 0;
388 
389 	if (width > len) {
390 		width = width - len;
391 		for (idx = 0; idx < width; idx++)
392 			buf[idx] = ' ';
393 	} else {
394 		width = 0;
395 	}
396 
397 	for (idx = 0; idx < len; ++idx)
398 		buf[idx + width] = tmp[len - idx - 1];
399 
400 	return len + width;
401 }
402 
403 #define SIGN	1		/* unsigned/signed, must be 1 */
404 #define LEFT	2		/* left justified */
405 #define PLUS	4		/* show plus */
406 #define SPACE	8		/* space if plus */
407 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
408 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
409 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
410 
411 static_assert(SIGN == 1);
412 static_assert(ZEROPAD == ('0' - ' '));
413 static_assert(SMALL == ('a' ^ 'A'));
414 
415 enum format_type {
416 	FORMAT_TYPE_NONE, /* Just a string part */
417 	FORMAT_TYPE_WIDTH,
418 	FORMAT_TYPE_PRECISION,
419 	FORMAT_TYPE_CHAR,
420 	FORMAT_TYPE_STR,
421 	FORMAT_TYPE_PTR,
422 	FORMAT_TYPE_PERCENT_CHAR,
423 	FORMAT_TYPE_INVALID,
424 	FORMAT_TYPE_LONG_LONG,
425 	FORMAT_TYPE_ULONG,
426 	FORMAT_TYPE_LONG,
427 	FORMAT_TYPE_UBYTE,
428 	FORMAT_TYPE_BYTE,
429 	FORMAT_TYPE_USHORT,
430 	FORMAT_TYPE_SHORT,
431 	FORMAT_TYPE_UINT,
432 	FORMAT_TYPE_INT,
433 	FORMAT_TYPE_SIZE_T,
434 	FORMAT_TYPE_PTRDIFF
435 };
436 
437 struct printf_spec {
438 	unsigned int	type:8;		/* format_type enum */
439 	signed int	field_width:24;	/* width of output field */
440 	unsigned int	flags:8;	/* flags to number() */
441 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
442 	signed int	precision:16;	/* # of digits/chars */
443 } __packed;
444 static_assert(sizeof(struct printf_spec) == 8);
445 
446 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
447 #define PRECISION_MAX ((1 << 15) - 1)
448 
449 static noinline_for_stack
450 char *number(char *buf, char *end, unsigned long long num,
451 	     struct printf_spec spec)
452 {
453 	/* put_dec requires 2-byte alignment of the buffer. */
454 	char tmp[3 * sizeof(num)] __aligned(2);
455 	char sign;
456 	char locase;
457 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
458 	int i;
459 	bool is_zero = num == 0LL;
460 	int field_width = spec.field_width;
461 	int precision = spec.precision;
462 
463 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
464 	 * produces same digits or (maybe lowercased) letters */
465 	locase = (spec.flags & SMALL);
466 	if (spec.flags & LEFT)
467 		spec.flags &= ~ZEROPAD;
468 	sign = 0;
469 	if (spec.flags & SIGN) {
470 		if ((signed long long)num < 0) {
471 			sign = '-';
472 			num = -(signed long long)num;
473 			field_width--;
474 		} else if (spec.flags & PLUS) {
475 			sign = '+';
476 			field_width--;
477 		} else if (spec.flags & SPACE) {
478 			sign = ' ';
479 			field_width--;
480 		}
481 	}
482 	if (need_pfx) {
483 		if (spec.base == 16)
484 			field_width -= 2;
485 		else if (!is_zero)
486 			field_width--;
487 	}
488 
489 	/* generate full string in tmp[], in reverse order */
490 	i = 0;
491 	if (num < spec.base)
492 		tmp[i++] = hex_asc_upper[num] | locase;
493 	else if (spec.base != 10) { /* 8 or 16 */
494 		int mask = spec.base - 1;
495 		int shift = 3;
496 
497 		if (spec.base == 16)
498 			shift = 4;
499 		do {
500 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
501 			num >>= shift;
502 		} while (num);
503 	} else { /* base 10 */
504 		i = put_dec(tmp, num) - tmp;
505 	}
506 
507 	/* printing 100 using %2d gives "100", not "00" */
508 	if (i > precision)
509 		precision = i;
510 	/* leading space padding */
511 	field_width -= precision;
512 	if (!(spec.flags & (ZEROPAD | LEFT))) {
513 		while (--field_width >= 0) {
514 			if (buf < end)
515 				*buf = ' ';
516 			++buf;
517 		}
518 	}
519 	/* sign */
520 	if (sign) {
521 		if (buf < end)
522 			*buf = sign;
523 		++buf;
524 	}
525 	/* "0x" / "0" prefix */
526 	if (need_pfx) {
527 		if (spec.base == 16 || !is_zero) {
528 			if (buf < end)
529 				*buf = '0';
530 			++buf;
531 		}
532 		if (spec.base == 16) {
533 			if (buf < end)
534 				*buf = ('X' | locase);
535 			++buf;
536 		}
537 	}
538 	/* zero or space padding */
539 	if (!(spec.flags & LEFT)) {
540 		char c = ' ' + (spec.flags & ZEROPAD);
541 
542 		while (--field_width >= 0) {
543 			if (buf < end)
544 				*buf = c;
545 			++buf;
546 		}
547 	}
548 	/* hmm even more zero padding? */
549 	while (i <= --precision) {
550 		if (buf < end)
551 			*buf = '0';
552 		++buf;
553 	}
554 	/* actual digits of result */
555 	while (--i >= 0) {
556 		if (buf < end)
557 			*buf = tmp[i];
558 		++buf;
559 	}
560 	/* trailing space padding */
561 	while (--field_width >= 0) {
562 		if (buf < end)
563 			*buf = ' ';
564 		++buf;
565 	}
566 
567 	return buf;
568 }
569 
570 static noinline_for_stack
571 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
572 {
573 	struct printf_spec spec;
574 
575 	spec.type = FORMAT_TYPE_PTR;
576 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
577 	spec.flags = SPECIAL | SMALL | ZEROPAD;
578 	spec.base = 16;
579 	spec.precision = -1;
580 
581 	return number(buf, end, num, spec);
582 }
583 
584 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
585 {
586 	size_t size;
587 	if (buf >= end)	/* nowhere to put anything */
588 		return;
589 	size = end - buf;
590 	if (size <= spaces) {
591 		memset(buf, ' ', size);
592 		return;
593 	}
594 	if (len) {
595 		if (len > size - spaces)
596 			len = size - spaces;
597 		memmove(buf + spaces, buf, len);
598 	}
599 	memset(buf, ' ', spaces);
600 }
601 
602 /*
603  * Handle field width padding for a string.
604  * @buf: current buffer position
605  * @n: length of string
606  * @end: end of output buffer
607  * @spec: for field width and flags
608  * Returns: new buffer position after padding.
609  */
610 static noinline_for_stack
611 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
612 {
613 	unsigned spaces;
614 
615 	if (likely(n >= spec.field_width))
616 		return buf;
617 	/* we want to pad the sucker */
618 	spaces = spec.field_width - n;
619 	if (!(spec.flags & LEFT)) {
620 		move_right(buf - n, end, n, spaces);
621 		return buf + spaces;
622 	}
623 	while (spaces--) {
624 		if (buf < end)
625 			*buf = ' ';
626 		++buf;
627 	}
628 	return buf;
629 }
630 
631 /* Handle string from a well known address. */
632 static char *string_nocheck(char *buf, char *end, const char *s,
633 			    struct printf_spec spec)
634 {
635 	int len = 0;
636 	int lim = spec.precision;
637 
638 	while (lim--) {
639 		char c = *s++;
640 		if (!c)
641 			break;
642 		if (buf < end)
643 			*buf = c;
644 		++buf;
645 		++len;
646 	}
647 	return widen_string(buf, len, end, spec);
648 }
649 
650 static char *err_ptr(char *buf, char *end, void *ptr,
651 		     struct printf_spec spec)
652 {
653 	int err = PTR_ERR(ptr);
654 	const char *sym = errname(err);
655 
656 	if (sym)
657 		return string_nocheck(buf, end, sym, spec);
658 
659 	/*
660 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
661 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
662 	 * printing it as its decimal representation.
663 	 */
664 	spec.flags |= SIGN;
665 	spec.base = 10;
666 	return number(buf, end, err, spec);
667 }
668 
669 /* Be careful: error messages must fit into the given buffer. */
670 static char *error_string(char *buf, char *end, const char *s,
671 			  struct printf_spec spec)
672 {
673 	/*
674 	 * Hard limit to avoid a completely insane messages. It actually
675 	 * works pretty well because most error messages are in
676 	 * the many pointer format modifiers.
677 	 */
678 	if (spec.precision == -1)
679 		spec.precision = 2 * sizeof(void *);
680 
681 	return string_nocheck(buf, end, s, spec);
682 }
683 
684 /*
685  * Do not call any complex external code here. Nested printk()/vsprintf()
686  * might cause infinite loops. Failures might break printk() and would
687  * be hard to debug.
688  */
689 static const char *check_pointer_msg(const void *ptr)
690 {
691 	if (!ptr)
692 		return "(null)";
693 
694 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
695 		return "(efault)";
696 
697 	return NULL;
698 }
699 
700 static int check_pointer(char **buf, char *end, const void *ptr,
701 			 struct printf_spec spec)
702 {
703 	const char *err_msg;
704 
705 	err_msg = check_pointer_msg(ptr);
706 	if (err_msg) {
707 		*buf = error_string(*buf, end, err_msg, spec);
708 		return -EFAULT;
709 	}
710 
711 	return 0;
712 }
713 
714 static noinline_for_stack
715 char *string(char *buf, char *end, const char *s,
716 	     struct printf_spec spec)
717 {
718 	if (check_pointer(&buf, end, s, spec))
719 		return buf;
720 
721 	return string_nocheck(buf, end, s, spec);
722 }
723 
724 static char *pointer_string(char *buf, char *end,
725 			    const void *ptr,
726 			    struct printf_spec spec)
727 {
728 	spec.base = 16;
729 	spec.flags |= SMALL;
730 	if (spec.field_width == -1) {
731 		spec.field_width = 2 * sizeof(ptr);
732 		spec.flags |= ZEROPAD;
733 	}
734 
735 	return number(buf, end, (unsigned long int)ptr, spec);
736 }
737 
738 /* Make pointers available for printing early in the boot sequence. */
739 static int debug_boot_weak_hash __ro_after_init;
740 
741 static int __init debug_boot_weak_hash_enable(char *str)
742 {
743 	debug_boot_weak_hash = 1;
744 	pr_info("debug_boot_weak_hash enabled\n");
745 	return 0;
746 }
747 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
748 
749 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
750 static siphash_key_t ptr_key __read_mostly;
751 
752 static void enable_ptr_key_workfn(struct work_struct *work)
753 {
754 	get_random_bytes(&ptr_key, sizeof(ptr_key));
755 	/* Needs to run from preemptible context */
756 	static_branch_disable(&not_filled_random_ptr_key);
757 }
758 
759 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
760 
761 static void fill_random_ptr_key(struct random_ready_callback *unused)
762 {
763 	/* This may be in an interrupt handler. */
764 	queue_work(system_unbound_wq, &enable_ptr_key_work);
765 }
766 
767 static struct random_ready_callback random_ready = {
768 	.func = fill_random_ptr_key
769 };
770 
771 static int __init initialize_ptr_random(void)
772 {
773 	int key_size = sizeof(ptr_key);
774 	int ret;
775 
776 	/* Use hw RNG if available. */
777 	if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
778 		static_branch_disable(&not_filled_random_ptr_key);
779 		return 0;
780 	}
781 
782 	ret = add_random_ready_callback(&random_ready);
783 	if (!ret) {
784 		return 0;
785 	} else if (ret == -EALREADY) {
786 		/* This is in preemptible context */
787 		enable_ptr_key_workfn(&enable_ptr_key_work);
788 		return 0;
789 	}
790 
791 	return ret;
792 }
793 early_initcall(initialize_ptr_random);
794 
795 /* Maps a pointer to a 32 bit unique identifier. */
796 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
797 {
798 	unsigned long hashval;
799 
800 	if (static_branch_unlikely(&not_filled_random_ptr_key))
801 		return -EAGAIN;
802 
803 #ifdef CONFIG_64BIT
804 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
805 	/*
806 	 * Mask off the first 32 bits, this makes explicit that we have
807 	 * modified the address (and 32 bits is plenty for a unique ID).
808 	 */
809 	hashval = hashval & 0xffffffff;
810 #else
811 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
812 #endif
813 	*hashval_out = hashval;
814 	return 0;
815 }
816 
817 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
818 {
819 	return __ptr_to_hashval(ptr, hashval_out);
820 }
821 
822 static char *ptr_to_id(char *buf, char *end, const void *ptr,
823 		       struct printf_spec spec)
824 {
825 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
826 	unsigned long hashval;
827 	int ret;
828 
829 	/*
830 	 * Print the real pointer value for NULL and error pointers,
831 	 * as they are not actual addresses.
832 	 */
833 	if (IS_ERR_OR_NULL(ptr))
834 		return pointer_string(buf, end, ptr, spec);
835 
836 	/* When debugging early boot use non-cryptographically secure hash. */
837 	if (unlikely(debug_boot_weak_hash)) {
838 		hashval = hash_long((unsigned long)ptr, 32);
839 		return pointer_string(buf, end, (const void *)hashval, spec);
840 	}
841 
842 	ret = __ptr_to_hashval(ptr, &hashval);
843 	if (ret) {
844 		spec.field_width = 2 * sizeof(ptr);
845 		/* string length must be less than default_width */
846 		return error_string(buf, end, str, spec);
847 	}
848 
849 	return pointer_string(buf, end, (const void *)hashval, spec);
850 }
851 
852 int kptr_restrict __read_mostly;
853 
854 static noinline_for_stack
855 char *restricted_pointer(char *buf, char *end, const void *ptr,
856 			 struct printf_spec spec)
857 {
858 	switch (kptr_restrict) {
859 	case 0:
860 		/* Handle as %p, hash and do _not_ leak addresses. */
861 		return ptr_to_id(buf, end, ptr, spec);
862 	case 1: {
863 		const struct cred *cred;
864 
865 		/*
866 		 * kptr_restrict==1 cannot be used in IRQ context
867 		 * because its test for CAP_SYSLOG would be meaningless.
868 		 */
869 		if (in_irq() || in_serving_softirq() || in_nmi()) {
870 			if (spec.field_width == -1)
871 				spec.field_width = 2 * sizeof(ptr);
872 			return error_string(buf, end, "pK-error", spec);
873 		}
874 
875 		/*
876 		 * Only print the real pointer value if the current
877 		 * process has CAP_SYSLOG and is running with the
878 		 * same credentials it started with. This is because
879 		 * access to files is checked at open() time, but %pK
880 		 * checks permission at read() time. We don't want to
881 		 * leak pointer values if a binary opens a file using
882 		 * %pK and then elevates privileges before reading it.
883 		 */
884 		cred = current_cred();
885 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
886 		    !uid_eq(cred->euid, cred->uid) ||
887 		    !gid_eq(cred->egid, cred->gid))
888 			ptr = NULL;
889 		break;
890 	}
891 	case 2:
892 	default:
893 		/* Always print 0's for %pK */
894 		ptr = NULL;
895 		break;
896 	}
897 
898 	return pointer_string(buf, end, ptr, spec);
899 }
900 
901 static noinline_for_stack
902 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
903 		  const char *fmt)
904 {
905 	const char *array[4], *s;
906 	const struct dentry *p;
907 	int depth;
908 	int i, n;
909 
910 	switch (fmt[1]) {
911 		case '2': case '3': case '4':
912 			depth = fmt[1] - '0';
913 			break;
914 		default:
915 			depth = 1;
916 	}
917 
918 	rcu_read_lock();
919 	for (i = 0; i < depth; i++, d = p) {
920 		if (check_pointer(&buf, end, d, spec)) {
921 			rcu_read_unlock();
922 			return buf;
923 		}
924 
925 		p = READ_ONCE(d->d_parent);
926 		array[i] = READ_ONCE(d->d_name.name);
927 		if (p == d) {
928 			if (i)
929 				array[i] = "";
930 			i++;
931 			break;
932 		}
933 	}
934 	s = array[--i];
935 	for (n = 0; n != spec.precision; n++, buf++) {
936 		char c = *s++;
937 		if (!c) {
938 			if (!i)
939 				break;
940 			c = '/';
941 			s = array[--i];
942 		}
943 		if (buf < end)
944 			*buf = c;
945 	}
946 	rcu_read_unlock();
947 	return widen_string(buf, n, end, spec);
948 }
949 
950 static noinline_for_stack
951 char *file_dentry_name(char *buf, char *end, const struct file *f,
952 			struct printf_spec spec, const char *fmt)
953 {
954 	if (check_pointer(&buf, end, f, spec))
955 		return buf;
956 
957 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
958 }
959 #ifdef CONFIG_BLOCK
960 static noinline_for_stack
961 char *bdev_name(char *buf, char *end, struct block_device *bdev,
962 		struct printf_spec spec, const char *fmt)
963 {
964 	struct gendisk *hd;
965 
966 	if (check_pointer(&buf, end, bdev, spec))
967 		return buf;
968 
969 	hd = bdev->bd_disk;
970 	buf = string(buf, end, hd->disk_name, spec);
971 	if (bdev->bd_partno) {
972 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
973 			if (buf < end)
974 				*buf = 'p';
975 			buf++;
976 		}
977 		buf = number(buf, end, bdev->bd_partno, spec);
978 	}
979 	return buf;
980 }
981 #endif
982 
983 static noinline_for_stack
984 char *symbol_string(char *buf, char *end, void *ptr,
985 		    struct printf_spec spec, const char *fmt)
986 {
987 	unsigned long value;
988 #ifdef CONFIG_KALLSYMS
989 	char sym[KSYM_SYMBOL_LEN];
990 #endif
991 
992 	if (fmt[1] == 'R')
993 		ptr = __builtin_extract_return_addr(ptr);
994 	value = (unsigned long)ptr;
995 
996 #ifdef CONFIG_KALLSYMS
997 	if (*fmt == 'B' && fmt[1] == 'b')
998 		sprint_backtrace_build_id(sym, value);
999 	else if (*fmt == 'B')
1000 		sprint_backtrace(sym, value);
1001 	else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1002 		sprint_symbol_build_id(sym, value);
1003 	else if (*fmt != 's')
1004 		sprint_symbol(sym, value);
1005 	else
1006 		sprint_symbol_no_offset(sym, value);
1007 
1008 	return string_nocheck(buf, end, sym, spec);
1009 #else
1010 	return special_hex_number(buf, end, value, sizeof(void *));
1011 #endif
1012 }
1013 
1014 static const struct printf_spec default_str_spec = {
1015 	.field_width = -1,
1016 	.precision = -1,
1017 };
1018 
1019 static const struct printf_spec default_flag_spec = {
1020 	.base = 16,
1021 	.precision = -1,
1022 	.flags = SPECIAL | SMALL,
1023 };
1024 
1025 static const struct printf_spec default_dec_spec = {
1026 	.base = 10,
1027 	.precision = -1,
1028 };
1029 
1030 static const struct printf_spec default_dec02_spec = {
1031 	.base = 10,
1032 	.field_width = 2,
1033 	.precision = -1,
1034 	.flags = ZEROPAD,
1035 };
1036 
1037 static const struct printf_spec default_dec04_spec = {
1038 	.base = 10,
1039 	.field_width = 4,
1040 	.precision = -1,
1041 	.flags = ZEROPAD,
1042 };
1043 
1044 static noinline_for_stack
1045 char *resource_string(char *buf, char *end, struct resource *res,
1046 		      struct printf_spec spec, const char *fmt)
1047 {
1048 #ifndef IO_RSRC_PRINTK_SIZE
1049 #define IO_RSRC_PRINTK_SIZE	6
1050 #endif
1051 
1052 #ifndef MEM_RSRC_PRINTK_SIZE
1053 #define MEM_RSRC_PRINTK_SIZE	10
1054 #endif
1055 	static const struct printf_spec io_spec = {
1056 		.base = 16,
1057 		.field_width = IO_RSRC_PRINTK_SIZE,
1058 		.precision = -1,
1059 		.flags = SPECIAL | SMALL | ZEROPAD,
1060 	};
1061 	static const struct printf_spec mem_spec = {
1062 		.base = 16,
1063 		.field_width = MEM_RSRC_PRINTK_SIZE,
1064 		.precision = -1,
1065 		.flags = SPECIAL | SMALL | ZEROPAD,
1066 	};
1067 	static const struct printf_spec bus_spec = {
1068 		.base = 16,
1069 		.field_width = 2,
1070 		.precision = -1,
1071 		.flags = SMALL | ZEROPAD,
1072 	};
1073 	static const struct printf_spec str_spec = {
1074 		.field_width = -1,
1075 		.precision = 10,
1076 		.flags = LEFT,
1077 	};
1078 
1079 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1080 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1081 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1082 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1083 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1084 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1085 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1086 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1087 
1088 	char *p = sym, *pend = sym + sizeof(sym);
1089 	int decode = (fmt[0] == 'R') ? 1 : 0;
1090 	const struct printf_spec *specp;
1091 
1092 	if (check_pointer(&buf, end, res, spec))
1093 		return buf;
1094 
1095 	*p++ = '[';
1096 	if (res->flags & IORESOURCE_IO) {
1097 		p = string_nocheck(p, pend, "io  ", str_spec);
1098 		specp = &io_spec;
1099 	} else if (res->flags & IORESOURCE_MEM) {
1100 		p = string_nocheck(p, pend, "mem ", str_spec);
1101 		specp = &mem_spec;
1102 	} else if (res->flags & IORESOURCE_IRQ) {
1103 		p = string_nocheck(p, pend, "irq ", str_spec);
1104 		specp = &default_dec_spec;
1105 	} else if (res->flags & IORESOURCE_DMA) {
1106 		p = string_nocheck(p, pend, "dma ", str_spec);
1107 		specp = &default_dec_spec;
1108 	} else if (res->flags & IORESOURCE_BUS) {
1109 		p = string_nocheck(p, pend, "bus ", str_spec);
1110 		specp = &bus_spec;
1111 	} else {
1112 		p = string_nocheck(p, pend, "??? ", str_spec);
1113 		specp = &mem_spec;
1114 		decode = 0;
1115 	}
1116 	if (decode && res->flags & IORESOURCE_UNSET) {
1117 		p = string_nocheck(p, pend, "size ", str_spec);
1118 		p = number(p, pend, resource_size(res), *specp);
1119 	} else {
1120 		p = number(p, pend, res->start, *specp);
1121 		if (res->start != res->end) {
1122 			*p++ = '-';
1123 			p = number(p, pend, res->end, *specp);
1124 		}
1125 	}
1126 	if (decode) {
1127 		if (res->flags & IORESOURCE_MEM_64)
1128 			p = string_nocheck(p, pend, " 64bit", str_spec);
1129 		if (res->flags & IORESOURCE_PREFETCH)
1130 			p = string_nocheck(p, pend, " pref", str_spec);
1131 		if (res->flags & IORESOURCE_WINDOW)
1132 			p = string_nocheck(p, pend, " window", str_spec);
1133 		if (res->flags & IORESOURCE_DISABLED)
1134 			p = string_nocheck(p, pend, " disabled", str_spec);
1135 	} else {
1136 		p = string_nocheck(p, pend, " flags ", str_spec);
1137 		p = number(p, pend, res->flags, default_flag_spec);
1138 	}
1139 	*p++ = ']';
1140 	*p = '\0';
1141 
1142 	return string_nocheck(buf, end, sym, spec);
1143 }
1144 
1145 static noinline_for_stack
1146 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1147 		 const char *fmt)
1148 {
1149 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1150 				   negative value, fallback to the default */
1151 	char separator;
1152 
1153 	if (spec.field_width == 0)
1154 		/* nothing to print */
1155 		return buf;
1156 
1157 	if (check_pointer(&buf, end, addr, spec))
1158 		return buf;
1159 
1160 	switch (fmt[1]) {
1161 	case 'C':
1162 		separator = ':';
1163 		break;
1164 	case 'D':
1165 		separator = '-';
1166 		break;
1167 	case 'N':
1168 		separator = 0;
1169 		break;
1170 	default:
1171 		separator = ' ';
1172 		break;
1173 	}
1174 
1175 	if (spec.field_width > 0)
1176 		len = min_t(int, spec.field_width, 64);
1177 
1178 	for (i = 0; i < len; ++i) {
1179 		if (buf < end)
1180 			*buf = hex_asc_hi(addr[i]);
1181 		++buf;
1182 		if (buf < end)
1183 			*buf = hex_asc_lo(addr[i]);
1184 		++buf;
1185 
1186 		if (separator && i != len - 1) {
1187 			if (buf < end)
1188 				*buf = separator;
1189 			++buf;
1190 		}
1191 	}
1192 
1193 	return buf;
1194 }
1195 
1196 static noinline_for_stack
1197 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1198 		    struct printf_spec spec, const char *fmt)
1199 {
1200 	const int CHUNKSZ = 32;
1201 	int nr_bits = max_t(int, spec.field_width, 0);
1202 	int i, chunksz;
1203 	bool first = true;
1204 
1205 	if (check_pointer(&buf, end, bitmap, spec))
1206 		return buf;
1207 
1208 	/* reused to print numbers */
1209 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1210 
1211 	chunksz = nr_bits & (CHUNKSZ - 1);
1212 	if (chunksz == 0)
1213 		chunksz = CHUNKSZ;
1214 
1215 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1216 	for (; i >= 0; i -= CHUNKSZ) {
1217 		u32 chunkmask, val;
1218 		int word, bit;
1219 
1220 		chunkmask = ((1ULL << chunksz) - 1);
1221 		word = i / BITS_PER_LONG;
1222 		bit = i % BITS_PER_LONG;
1223 		val = (bitmap[word] >> bit) & chunkmask;
1224 
1225 		if (!first) {
1226 			if (buf < end)
1227 				*buf = ',';
1228 			buf++;
1229 		}
1230 		first = false;
1231 
1232 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1233 		buf = number(buf, end, val, spec);
1234 
1235 		chunksz = CHUNKSZ;
1236 	}
1237 	return buf;
1238 }
1239 
1240 static noinline_for_stack
1241 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1242 			 struct printf_spec spec, const char *fmt)
1243 {
1244 	int nr_bits = max_t(int, spec.field_width, 0);
1245 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
1246 	int cur, rbot, rtop;
1247 	bool first = true;
1248 
1249 	if (check_pointer(&buf, end, bitmap, spec))
1250 		return buf;
1251 
1252 	rbot = cur = find_first_bit(bitmap, nr_bits);
1253 	while (cur < nr_bits) {
1254 		rtop = cur;
1255 		cur = find_next_bit(bitmap, nr_bits, cur + 1);
1256 		if (cur < nr_bits && cur <= rtop + 1)
1257 			continue;
1258 
1259 		if (!first) {
1260 			if (buf < end)
1261 				*buf = ',';
1262 			buf++;
1263 		}
1264 		first = false;
1265 
1266 		buf = number(buf, end, rbot, default_dec_spec);
1267 		if (rbot < rtop) {
1268 			if (buf < end)
1269 				*buf = '-';
1270 			buf++;
1271 
1272 			buf = number(buf, end, rtop, default_dec_spec);
1273 		}
1274 
1275 		rbot = cur;
1276 	}
1277 	return buf;
1278 }
1279 
1280 static noinline_for_stack
1281 char *mac_address_string(char *buf, char *end, u8 *addr,
1282 			 struct printf_spec spec, const char *fmt)
1283 {
1284 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1285 	char *p = mac_addr;
1286 	int i;
1287 	char separator;
1288 	bool reversed = false;
1289 
1290 	if (check_pointer(&buf, end, addr, spec))
1291 		return buf;
1292 
1293 	switch (fmt[1]) {
1294 	case 'F':
1295 		separator = '-';
1296 		break;
1297 
1298 	case 'R':
1299 		reversed = true;
1300 		fallthrough;
1301 
1302 	default:
1303 		separator = ':';
1304 		break;
1305 	}
1306 
1307 	for (i = 0; i < 6; i++) {
1308 		if (reversed)
1309 			p = hex_byte_pack(p, addr[5 - i]);
1310 		else
1311 			p = hex_byte_pack(p, addr[i]);
1312 
1313 		if (fmt[0] == 'M' && i != 5)
1314 			*p++ = separator;
1315 	}
1316 	*p = '\0';
1317 
1318 	return string_nocheck(buf, end, mac_addr, spec);
1319 }
1320 
1321 static noinline_for_stack
1322 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1323 {
1324 	int i;
1325 	bool leading_zeros = (fmt[0] == 'i');
1326 	int index;
1327 	int step;
1328 
1329 	switch (fmt[2]) {
1330 	case 'h':
1331 #ifdef __BIG_ENDIAN
1332 		index = 0;
1333 		step = 1;
1334 #else
1335 		index = 3;
1336 		step = -1;
1337 #endif
1338 		break;
1339 	case 'l':
1340 		index = 3;
1341 		step = -1;
1342 		break;
1343 	case 'n':
1344 	case 'b':
1345 	default:
1346 		index = 0;
1347 		step = 1;
1348 		break;
1349 	}
1350 	for (i = 0; i < 4; i++) {
1351 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1352 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1353 		if (leading_zeros) {
1354 			if (digits < 3)
1355 				*p++ = '0';
1356 			if (digits < 2)
1357 				*p++ = '0';
1358 		}
1359 		/* reverse the digits in the quad */
1360 		while (digits--)
1361 			*p++ = temp[digits];
1362 		if (i < 3)
1363 			*p++ = '.';
1364 		index += step;
1365 	}
1366 	*p = '\0';
1367 
1368 	return p;
1369 }
1370 
1371 static noinline_for_stack
1372 char *ip6_compressed_string(char *p, const char *addr)
1373 {
1374 	int i, j, range;
1375 	unsigned char zerolength[8];
1376 	int longest = 1;
1377 	int colonpos = -1;
1378 	u16 word;
1379 	u8 hi, lo;
1380 	bool needcolon = false;
1381 	bool useIPv4;
1382 	struct in6_addr in6;
1383 
1384 	memcpy(&in6, addr, sizeof(struct in6_addr));
1385 
1386 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1387 
1388 	memset(zerolength, 0, sizeof(zerolength));
1389 
1390 	if (useIPv4)
1391 		range = 6;
1392 	else
1393 		range = 8;
1394 
1395 	/* find position of longest 0 run */
1396 	for (i = 0; i < range; i++) {
1397 		for (j = i; j < range; j++) {
1398 			if (in6.s6_addr16[j] != 0)
1399 				break;
1400 			zerolength[i]++;
1401 		}
1402 	}
1403 	for (i = 0; i < range; i++) {
1404 		if (zerolength[i] > longest) {
1405 			longest = zerolength[i];
1406 			colonpos = i;
1407 		}
1408 	}
1409 	if (longest == 1)		/* don't compress a single 0 */
1410 		colonpos = -1;
1411 
1412 	/* emit address */
1413 	for (i = 0; i < range; i++) {
1414 		if (i == colonpos) {
1415 			if (needcolon || i == 0)
1416 				*p++ = ':';
1417 			*p++ = ':';
1418 			needcolon = false;
1419 			i += longest - 1;
1420 			continue;
1421 		}
1422 		if (needcolon) {
1423 			*p++ = ':';
1424 			needcolon = false;
1425 		}
1426 		/* hex u16 without leading 0s */
1427 		word = ntohs(in6.s6_addr16[i]);
1428 		hi = word >> 8;
1429 		lo = word & 0xff;
1430 		if (hi) {
1431 			if (hi > 0x0f)
1432 				p = hex_byte_pack(p, hi);
1433 			else
1434 				*p++ = hex_asc_lo(hi);
1435 			p = hex_byte_pack(p, lo);
1436 		}
1437 		else if (lo > 0x0f)
1438 			p = hex_byte_pack(p, lo);
1439 		else
1440 			*p++ = hex_asc_lo(lo);
1441 		needcolon = true;
1442 	}
1443 
1444 	if (useIPv4) {
1445 		if (needcolon)
1446 			*p++ = ':';
1447 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1448 	}
1449 	*p = '\0';
1450 
1451 	return p;
1452 }
1453 
1454 static noinline_for_stack
1455 char *ip6_string(char *p, const char *addr, const char *fmt)
1456 {
1457 	int i;
1458 
1459 	for (i = 0; i < 8; i++) {
1460 		p = hex_byte_pack(p, *addr++);
1461 		p = hex_byte_pack(p, *addr++);
1462 		if (fmt[0] == 'I' && i != 7)
1463 			*p++ = ':';
1464 	}
1465 	*p = '\0';
1466 
1467 	return p;
1468 }
1469 
1470 static noinline_for_stack
1471 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1472 		      struct printf_spec spec, const char *fmt)
1473 {
1474 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1475 
1476 	if (fmt[0] == 'I' && fmt[2] == 'c')
1477 		ip6_compressed_string(ip6_addr, addr);
1478 	else
1479 		ip6_string(ip6_addr, addr, fmt);
1480 
1481 	return string_nocheck(buf, end, ip6_addr, spec);
1482 }
1483 
1484 static noinline_for_stack
1485 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1486 		      struct printf_spec spec, const char *fmt)
1487 {
1488 	char ip4_addr[sizeof("255.255.255.255")];
1489 
1490 	ip4_string(ip4_addr, addr, fmt);
1491 
1492 	return string_nocheck(buf, end, ip4_addr, spec);
1493 }
1494 
1495 static noinline_for_stack
1496 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1497 			 struct printf_spec spec, const char *fmt)
1498 {
1499 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1500 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1501 		      sizeof(":12345") + sizeof("/123456789") +
1502 		      sizeof("%1234567890")];
1503 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1504 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1505 	char fmt6[2] = { fmt[0], '6' };
1506 	u8 off = 0;
1507 
1508 	fmt++;
1509 	while (isalpha(*++fmt)) {
1510 		switch (*fmt) {
1511 		case 'p':
1512 			have_p = true;
1513 			break;
1514 		case 'f':
1515 			have_f = true;
1516 			break;
1517 		case 's':
1518 			have_s = true;
1519 			break;
1520 		case 'c':
1521 			have_c = true;
1522 			break;
1523 		}
1524 	}
1525 
1526 	if (have_p || have_s || have_f) {
1527 		*p = '[';
1528 		off = 1;
1529 	}
1530 
1531 	if (fmt6[0] == 'I' && have_c)
1532 		p = ip6_compressed_string(ip6_addr + off, addr);
1533 	else
1534 		p = ip6_string(ip6_addr + off, addr, fmt6);
1535 
1536 	if (have_p || have_s || have_f)
1537 		*p++ = ']';
1538 
1539 	if (have_p) {
1540 		*p++ = ':';
1541 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1542 	}
1543 	if (have_f) {
1544 		*p++ = '/';
1545 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1546 					  IPV6_FLOWINFO_MASK), spec);
1547 	}
1548 	if (have_s) {
1549 		*p++ = '%';
1550 		p = number(p, pend, sa->sin6_scope_id, spec);
1551 	}
1552 	*p = '\0';
1553 
1554 	return string_nocheck(buf, end, ip6_addr, spec);
1555 }
1556 
1557 static noinline_for_stack
1558 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1559 			 struct printf_spec spec, const char *fmt)
1560 {
1561 	bool have_p = false;
1562 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1563 	char *pend = ip4_addr + sizeof(ip4_addr);
1564 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1565 	char fmt4[3] = { fmt[0], '4', 0 };
1566 
1567 	fmt++;
1568 	while (isalpha(*++fmt)) {
1569 		switch (*fmt) {
1570 		case 'p':
1571 			have_p = true;
1572 			break;
1573 		case 'h':
1574 		case 'l':
1575 		case 'n':
1576 		case 'b':
1577 			fmt4[2] = *fmt;
1578 			break;
1579 		}
1580 	}
1581 
1582 	p = ip4_string(ip4_addr, addr, fmt4);
1583 	if (have_p) {
1584 		*p++ = ':';
1585 		p = number(p, pend, ntohs(sa->sin_port), spec);
1586 	}
1587 	*p = '\0';
1588 
1589 	return string_nocheck(buf, end, ip4_addr, spec);
1590 }
1591 
1592 static noinline_for_stack
1593 char *ip_addr_string(char *buf, char *end, const void *ptr,
1594 		     struct printf_spec spec, const char *fmt)
1595 {
1596 	char *err_fmt_msg;
1597 
1598 	if (check_pointer(&buf, end, ptr, spec))
1599 		return buf;
1600 
1601 	switch (fmt[1]) {
1602 	case '6':
1603 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1604 	case '4':
1605 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1606 	case 'S': {
1607 		const union {
1608 			struct sockaddr		raw;
1609 			struct sockaddr_in	v4;
1610 			struct sockaddr_in6	v6;
1611 		} *sa = ptr;
1612 
1613 		switch (sa->raw.sa_family) {
1614 		case AF_INET:
1615 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1616 		case AF_INET6:
1617 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1618 		default:
1619 			return error_string(buf, end, "(einval)", spec);
1620 		}}
1621 	}
1622 
1623 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1624 	return error_string(buf, end, err_fmt_msg, spec);
1625 }
1626 
1627 static noinline_for_stack
1628 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1629 		     const char *fmt)
1630 {
1631 	bool found = true;
1632 	int count = 1;
1633 	unsigned int flags = 0;
1634 	int len;
1635 
1636 	if (spec.field_width == 0)
1637 		return buf;				/* nothing to print */
1638 
1639 	if (check_pointer(&buf, end, addr, spec))
1640 		return buf;
1641 
1642 	do {
1643 		switch (fmt[count++]) {
1644 		case 'a':
1645 			flags |= ESCAPE_ANY;
1646 			break;
1647 		case 'c':
1648 			flags |= ESCAPE_SPECIAL;
1649 			break;
1650 		case 'h':
1651 			flags |= ESCAPE_HEX;
1652 			break;
1653 		case 'n':
1654 			flags |= ESCAPE_NULL;
1655 			break;
1656 		case 'o':
1657 			flags |= ESCAPE_OCTAL;
1658 			break;
1659 		case 'p':
1660 			flags |= ESCAPE_NP;
1661 			break;
1662 		case 's':
1663 			flags |= ESCAPE_SPACE;
1664 			break;
1665 		default:
1666 			found = false;
1667 			break;
1668 		}
1669 	} while (found);
1670 
1671 	if (!flags)
1672 		flags = ESCAPE_ANY_NP;
1673 
1674 	len = spec.field_width < 0 ? 1 : spec.field_width;
1675 
1676 	/*
1677 	 * string_escape_mem() writes as many characters as it can to
1678 	 * the given buffer, and returns the total size of the output
1679 	 * had the buffer been big enough.
1680 	 */
1681 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1682 
1683 	return buf;
1684 }
1685 
1686 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1687 		       struct printf_spec spec, const char *fmt)
1688 {
1689 	va_list va;
1690 
1691 	if (check_pointer(&buf, end, va_fmt, spec))
1692 		return buf;
1693 
1694 	va_copy(va, *va_fmt->va);
1695 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1696 	va_end(va);
1697 
1698 	return buf;
1699 }
1700 
1701 static noinline_for_stack
1702 char *uuid_string(char *buf, char *end, const u8 *addr,
1703 		  struct printf_spec spec, const char *fmt)
1704 {
1705 	char uuid[UUID_STRING_LEN + 1];
1706 	char *p = uuid;
1707 	int i;
1708 	const u8 *index = uuid_index;
1709 	bool uc = false;
1710 
1711 	if (check_pointer(&buf, end, addr, spec))
1712 		return buf;
1713 
1714 	switch (*(++fmt)) {
1715 	case 'L':
1716 		uc = true;
1717 		fallthrough;
1718 	case 'l':
1719 		index = guid_index;
1720 		break;
1721 	case 'B':
1722 		uc = true;
1723 		break;
1724 	}
1725 
1726 	for (i = 0; i < 16; i++) {
1727 		if (uc)
1728 			p = hex_byte_pack_upper(p, addr[index[i]]);
1729 		else
1730 			p = hex_byte_pack(p, addr[index[i]]);
1731 		switch (i) {
1732 		case 3:
1733 		case 5:
1734 		case 7:
1735 		case 9:
1736 			*p++ = '-';
1737 			break;
1738 		}
1739 	}
1740 
1741 	*p = 0;
1742 
1743 	return string_nocheck(buf, end, uuid, spec);
1744 }
1745 
1746 static noinline_for_stack
1747 char *netdev_bits(char *buf, char *end, const void *addr,
1748 		  struct printf_spec spec,  const char *fmt)
1749 {
1750 	unsigned long long num;
1751 	int size;
1752 
1753 	if (check_pointer(&buf, end, addr, spec))
1754 		return buf;
1755 
1756 	switch (fmt[1]) {
1757 	case 'F':
1758 		num = *(const netdev_features_t *)addr;
1759 		size = sizeof(netdev_features_t);
1760 		break;
1761 	default:
1762 		return error_string(buf, end, "(%pN?)", spec);
1763 	}
1764 
1765 	return special_hex_number(buf, end, num, size);
1766 }
1767 
1768 static noinline_for_stack
1769 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1770 		    struct printf_spec spec, const char *fmt)
1771 {
1772 	char output[sizeof("0123 little-endian (0x01234567)")];
1773 	char *p = output;
1774 	unsigned int i;
1775 	u32 val;
1776 
1777 	if (fmt[1] != 'c' || fmt[2] != 'c')
1778 		return error_string(buf, end, "(%p4?)", spec);
1779 
1780 	if (check_pointer(&buf, end, fourcc, spec))
1781 		return buf;
1782 
1783 	val = *fourcc & ~BIT(31);
1784 
1785 	for (i = 0; i < sizeof(*fourcc); i++) {
1786 		unsigned char c = val >> (i * 8);
1787 
1788 		/* Print non-control ASCII characters as-is, dot otherwise */
1789 		*p++ = isascii(c) && isprint(c) ? c : '.';
1790 	}
1791 
1792 	strcpy(p, *fourcc & BIT(31) ? " big-endian" : " little-endian");
1793 	p += strlen(p);
1794 
1795 	*p++ = ' ';
1796 	*p++ = '(';
1797 	p = special_hex_number(p, output + sizeof(output) - 2, *fourcc, sizeof(u32));
1798 	*p++ = ')';
1799 	*p = '\0';
1800 
1801 	return string(buf, end, output, spec);
1802 }
1803 
1804 static noinline_for_stack
1805 char *address_val(char *buf, char *end, const void *addr,
1806 		  struct printf_spec spec, const char *fmt)
1807 {
1808 	unsigned long long num;
1809 	int size;
1810 
1811 	if (check_pointer(&buf, end, addr, spec))
1812 		return buf;
1813 
1814 	switch (fmt[1]) {
1815 	case 'd':
1816 		num = *(const dma_addr_t *)addr;
1817 		size = sizeof(dma_addr_t);
1818 		break;
1819 	case 'p':
1820 	default:
1821 		num = *(const phys_addr_t *)addr;
1822 		size = sizeof(phys_addr_t);
1823 		break;
1824 	}
1825 
1826 	return special_hex_number(buf, end, num, size);
1827 }
1828 
1829 static noinline_for_stack
1830 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1831 {
1832 	int year = tm->tm_year + (r ? 0 : 1900);
1833 	int mon = tm->tm_mon + (r ? 0 : 1);
1834 
1835 	buf = number(buf, end, year, default_dec04_spec);
1836 	if (buf < end)
1837 		*buf = '-';
1838 	buf++;
1839 
1840 	buf = number(buf, end, mon, default_dec02_spec);
1841 	if (buf < end)
1842 		*buf = '-';
1843 	buf++;
1844 
1845 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1846 }
1847 
1848 static noinline_for_stack
1849 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1850 {
1851 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1852 	if (buf < end)
1853 		*buf = ':';
1854 	buf++;
1855 
1856 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1857 	if (buf < end)
1858 		*buf = ':';
1859 	buf++;
1860 
1861 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1862 }
1863 
1864 static noinline_for_stack
1865 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1866 	      struct printf_spec spec, const char *fmt)
1867 {
1868 	bool have_t = true, have_d = true;
1869 	bool raw = false, iso8601_separator = true;
1870 	bool found = true;
1871 	int count = 2;
1872 
1873 	if (check_pointer(&buf, end, tm, spec))
1874 		return buf;
1875 
1876 	switch (fmt[count]) {
1877 	case 'd':
1878 		have_t = false;
1879 		count++;
1880 		break;
1881 	case 't':
1882 		have_d = false;
1883 		count++;
1884 		break;
1885 	}
1886 
1887 	do {
1888 		switch (fmt[count++]) {
1889 		case 'r':
1890 			raw = true;
1891 			break;
1892 		case 's':
1893 			iso8601_separator = false;
1894 			break;
1895 		default:
1896 			found = false;
1897 			break;
1898 		}
1899 	} while (found);
1900 
1901 	if (have_d)
1902 		buf = date_str(buf, end, tm, raw);
1903 	if (have_d && have_t) {
1904 		if (buf < end)
1905 			*buf = iso8601_separator ? 'T' : ' ';
1906 		buf++;
1907 	}
1908 	if (have_t)
1909 		buf = time_str(buf, end, tm, raw);
1910 
1911 	return buf;
1912 }
1913 
1914 static noinline_for_stack
1915 char *time64_str(char *buf, char *end, const time64_t time,
1916 		 struct printf_spec spec, const char *fmt)
1917 {
1918 	struct rtc_time rtc_time;
1919 	struct tm tm;
1920 
1921 	time64_to_tm(time, 0, &tm);
1922 
1923 	rtc_time.tm_sec = tm.tm_sec;
1924 	rtc_time.tm_min = tm.tm_min;
1925 	rtc_time.tm_hour = tm.tm_hour;
1926 	rtc_time.tm_mday = tm.tm_mday;
1927 	rtc_time.tm_mon = tm.tm_mon;
1928 	rtc_time.tm_year = tm.tm_year;
1929 	rtc_time.tm_wday = tm.tm_wday;
1930 	rtc_time.tm_yday = tm.tm_yday;
1931 
1932 	rtc_time.tm_isdst = 0;
1933 
1934 	return rtc_str(buf, end, &rtc_time, spec, fmt);
1935 }
1936 
1937 static noinline_for_stack
1938 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1939 		    const char *fmt)
1940 {
1941 	switch (fmt[1]) {
1942 	case 'R':
1943 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1944 	case 'T':
1945 		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1946 	default:
1947 		return error_string(buf, end, "(%pt?)", spec);
1948 	}
1949 }
1950 
1951 static noinline_for_stack
1952 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1953 	    const char *fmt)
1954 {
1955 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1956 		return error_string(buf, end, "(%pC?)", spec);
1957 
1958 	if (check_pointer(&buf, end, clk, spec))
1959 		return buf;
1960 
1961 	switch (fmt[1]) {
1962 	case 'n':
1963 	default:
1964 #ifdef CONFIG_COMMON_CLK
1965 		return string(buf, end, __clk_get_name(clk), spec);
1966 #else
1967 		return ptr_to_id(buf, end, clk, spec);
1968 #endif
1969 	}
1970 }
1971 
1972 static
1973 char *format_flags(char *buf, char *end, unsigned long flags,
1974 					const struct trace_print_flags *names)
1975 {
1976 	unsigned long mask;
1977 
1978 	for ( ; flags && names->name; names++) {
1979 		mask = names->mask;
1980 		if ((flags & mask) != mask)
1981 			continue;
1982 
1983 		buf = string(buf, end, names->name, default_str_spec);
1984 
1985 		flags &= ~mask;
1986 		if (flags) {
1987 			if (buf < end)
1988 				*buf = '|';
1989 			buf++;
1990 		}
1991 	}
1992 
1993 	if (flags)
1994 		buf = number(buf, end, flags, default_flag_spec);
1995 
1996 	return buf;
1997 }
1998 
1999 struct page_flags_fields {
2000 	int width;
2001 	int shift;
2002 	int mask;
2003 	const struct printf_spec *spec;
2004 	const char *name;
2005 };
2006 
2007 static const struct page_flags_fields pff[] = {
2008 	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2009 	 &default_dec_spec, "section"},
2010 	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2011 	 &default_dec_spec, "node"},
2012 	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2013 	 &default_dec_spec, "zone"},
2014 	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2015 	 &default_flag_spec, "lastcpupid"},
2016 	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2017 	 &default_flag_spec, "kasantag"},
2018 };
2019 
2020 static
2021 char *format_page_flags(char *buf, char *end, unsigned long flags)
2022 {
2023 	unsigned long main_flags = flags & PAGEFLAGS_MASK;
2024 	bool append = false;
2025 	int i;
2026 
2027 	buf = number(buf, end, flags, default_flag_spec);
2028 	if (buf < end)
2029 		*buf = '(';
2030 	buf++;
2031 
2032 	/* Page flags from the main area. */
2033 	if (main_flags) {
2034 		buf = format_flags(buf, end, main_flags, pageflag_names);
2035 		append = true;
2036 	}
2037 
2038 	/* Page flags from the fields area */
2039 	for (i = 0; i < ARRAY_SIZE(pff); i++) {
2040 		/* Skip undefined fields. */
2041 		if (!pff[i].width)
2042 			continue;
2043 
2044 		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2045 		if (append) {
2046 			if (buf < end)
2047 				*buf = '|';
2048 			buf++;
2049 		}
2050 
2051 		buf = string(buf, end, pff[i].name, default_str_spec);
2052 		if (buf < end)
2053 			*buf = '=';
2054 		buf++;
2055 		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2056 			     *pff[i].spec);
2057 
2058 		append = true;
2059 	}
2060 	if (buf < end)
2061 		*buf = ')';
2062 	buf++;
2063 
2064 	return buf;
2065 }
2066 
2067 static noinline_for_stack
2068 char *flags_string(char *buf, char *end, void *flags_ptr,
2069 		   struct printf_spec spec, const char *fmt)
2070 {
2071 	unsigned long flags;
2072 	const struct trace_print_flags *names;
2073 
2074 	if (check_pointer(&buf, end, flags_ptr, spec))
2075 		return buf;
2076 
2077 	switch (fmt[1]) {
2078 	case 'p':
2079 		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2080 	case 'v':
2081 		flags = *(unsigned long *)flags_ptr;
2082 		names = vmaflag_names;
2083 		break;
2084 	case 'g':
2085 		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2086 		names = gfpflag_names;
2087 		break;
2088 	default:
2089 		return error_string(buf, end, "(%pG?)", spec);
2090 	}
2091 
2092 	return format_flags(buf, end, flags, names);
2093 }
2094 
2095 static noinline_for_stack
2096 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2097 			      char *end)
2098 {
2099 	int depth;
2100 
2101 	/* Loop starting from the root node to the current node. */
2102 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2103 		struct fwnode_handle *__fwnode =
2104 			fwnode_get_nth_parent(fwnode, depth);
2105 
2106 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2107 			     default_str_spec);
2108 		buf = string(buf, end, fwnode_get_name(__fwnode),
2109 			     default_str_spec);
2110 
2111 		fwnode_handle_put(__fwnode);
2112 	}
2113 
2114 	return buf;
2115 }
2116 
2117 static noinline_for_stack
2118 char *device_node_string(char *buf, char *end, struct device_node *dn,
2119 			 struct printf_spec spec, const char *fmt)
2120 {
2121 	char tbuf[sizeof("xxxx") + 1];
2122 	const char *p;
2123 	int ret;
2124 	char *buf_start = buf;
2125 	struct property *prop;
2126 	bool has_mult, pass;
2127 
2128 	struct printf_spec str_spec = spec;
2129 	str_spec.field_width = -1;
2130 
2131 	if (fmt[0] != 'F')
2132 		return error_string(buf, end, "(%pO?)", spec);
2133 
2134 	if (!IS_ENABLED(CONFIG_OF))
2135 		return error_string(buf, end, "(%pOF?)", spec);
2136 
2137 	if (check_pointer(&buf, end, dn, spec))
2138 		return buf;
2139 
2140 	/* simple case without anything any more format specifiers */
2141 	fmt++;
2142 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2143 		fmt = "f";
2144 
2145 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2146 		int precision;
2147 		if (pass) {
2148 			if (buf < end)
2149 				*buf = ':';
2150 			buf++;
2151 		}
2152 
2153 		switch (*fmt) {
2154 		case 'f':	/* full_name */
2155 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2156 						      end);
2157 			break;
2158 		case 'n':	/* name */
2159 			p = fwnode_get_name(of_fwnode_handle(dn));
2160 			precision = str_spec.precision;
2161 			str_spec.precision = strchrnul(p, '@') - p;
2162 			buf = string(buf, end, p, str_spec);
2163 			str_spec.precision = precision;
2164 			break;
2165 		case 'p':	/* phandle */
2166 			buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2167 			break;
2168 		case 'P':	/* path-spec */
2169 			p = fwnode_get_name(of_fwnode_handle(dn));
2170 			if (!p[1])
2171 				p = "/";
2172 			buf = string(buf, end, p, str_spec);
2173 			break;
2174 		case 'F':	/* flags */
2175 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2176 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2177 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2178 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2179 			tbuf[4] = 0;
2180 			buf = string_nocheck(buf, end, tbuf, str_spec);
2181 			break;
2182 		case 'c':	/* major compatible string */
2183 			ret = of_property_read_string(dn, "compatible", &p);
2184 			if (!ret)
2185 				buf = string(buf, end, p, str_spec);
2186 			break;
2187 		case 'C':	/* full compatible string */
2188 			has_mult = false;
2189 			of_property_for_each_string(dn, "compatible", prop, p) {
2190 				if (has_mult)
2191 					buf = string_nocheck(buf, end, ",", str_spec);
2192 				buf = string_nocheck(buf, end, "\"", str_spec);
2193 				buf = string(buf, end, p, str_spec);
2194 				buf = string_nocheck(buf, end, "\"", str_spec);
2195 
2196 				has_mult = true;
2197 			}
2198 			break;
2199 		default:
2200 			break;
2201 		}
2202 	}
2203 
2204 	return widen_string(buf, buf - buf_start, end, spec);
2205 }
2206 
2207 static noinline_for_stack
2208 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2209 		    struct printf_spec spec, const char *fmt)
2210 {
2211 	struct printf_spec str_spec = spec;
2212 	char *buf_start = buf;
2213 
2214 	str_spec.field_width = -1;
2215 
2216 	if (*fmt != 'w')
2217 		return error_string(buf, end, "(%pf?)", spec);
2218 
2219 	if (check_pointer(&buf, end, fwnode, spec))
2220 		return buf;
2221 
2222 	fmt++;
2223 
2224 	switch (*fmt) {
2225 	case 'P':	/* name */
2226 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2227 		break;
2228 	case 'f':	/* full_name */
2229 	default:
2230 		buf = fwnode_full_name_string(fwnode, buf, end);
2231 		break;
2232 	}
2233 
2234 	return widen_string(buf, buf - buf_start, end, spec);
2235 }
2236 
2237 /* Disable pointer hashing if requested */
2238 bool no_hash_pointers __ro_after_init;
2239 EXPORT_SYMBOL_GPL(no_hash_pointers);
2240 
2241 int __init no_hash_pointers_enable(char *str)
2242 {
2243 	if (no_hash_pointers)
2244 		return 0;
2245 
2246 	no_hash_pointers = true;
2247 
2248 	pr_warn("**********************************************************\n");
2249 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2250 	pr_warn("**                                                      **\n");
2251 	pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2252 	pr_warn("** via the console, logs, and other interfaces. This    **\n");
2253 	pr_warn("** might reduce the security of your system.            **\n");
2254 	pr_warn("**                                                      **\n");
2255 	pr_warn("** If you see this message and you are not debugging    **\n");
2256 	pr_warn("** the kernel, report this immediately to your system   **\n");
2257 	pr_warn("** administrator!                                       **\n");
2258 	pr_warn("**                                                      **\n");
2259 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2260 	pr_warn("**********************************************************\n");
2261 
2262 	return 0;
2263 }
2264 early_param("no_hash_pointers", no_hash_pointers_enable);
2265 
2266 /*
2267  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2268  * by an extra set of alphanumeric characters that are extended format
2269  * specifiers.
2270  *
2271  * Please update scripts/checkpatch.pl when adding/removing conversion
2272  * characters.  (Search for "check for vsprintf extension").
2273  *
2274  * Right now we handle:
2275  *
2276  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2277  * - 's' For symbolic direct pointers (or function descriptors) without offset
2278  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2279  * - 'S[R]b' as above with module build ID (for use in backtraces)
2280  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2281  *	    %ps and %pS. Be careful when re-using these specifiers.
2282  * - 'B' For backtraced symbolic direct pointers with offset
2283  * - 'Bb' as above with module build ID (for use in backtraces)
2284  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2285  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2286  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2287  *       width which must be explicitly specified either as part of the
2288  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2289  *       range-list format instead of hex format
2290  * - 'M' For a 6-byte MAC address, it prints the address in the
2291  *       usual colon-separated hex notation
2292  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2293  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2294  *       with a dash-separated hex notation
2295  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2296  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2297  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2298  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2299  *       [S][pfs]
2300  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2301  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2302  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2303  *       IPv6 omits the colons (01020304...0f)
2304  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2305  *       [S][pfs]
2306  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2307  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2308  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2309  * - 'I[6S]c' for IPv6 addresses printed as specified by
2310  *       https://tools.ietf.org/html/rfc5952
2311  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2312  *                of the following flags (see string_escape_mem() for the
2313  *                details):
2314  *                  a - ESCAPE_ANY
2315  *                  c - ESCAPE_SPECIAL
2316  *                  h - ESCAPE_HEX
2317  *                  n - ESCAPE_NULL
2318  *                  o - ESCAPE_OCTAL
2319  *                  p - ESCAPE_NP
2320  *                  s - ESCAPE_SPACE
2321  *                By default ESCAPE_ANY_NP is used.
2322  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2323  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2324  *       Options for %pU are:
2325  *         b big endian lower case hex (default)
2326  *         B big endian UPPER case hex
2327  *         l little endian lower case hex
2328  *         L little endian UPPER case hex
2329  *           big endian output byte order is:
2330  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2331  *           little endian output byte order is:
2332  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2333  * - 'V' For a struct va_format which contains a format string * and va_list *,
2334  *       call vsnprintf(->format, *->va_list).
2335  *       Implements a "recursive vsnprintf".
2336  *       Do not use this feature without some mechanism to verify the
2337  *       correctness of the format string and va_list arguments.
2338  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2339  *       Use only for procfs, sysfs and similar files, not printk(); please
2340  *       read the documentation (path below) first.
2341  * - 'NF' For a netdev_features_t
2342  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2343  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2344  *            a certain separator (' ' by default):
2345  *              C colon
2346  *              D dash
2347  *              N no separator
2348  *            The maximum supported length is 64 bytes of the input. Consider
2349  *            to use print_hex_dump() for the larger input.
2350  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2351  *           (default assumed to be phys_addr_t, passed by reference)
2352  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2353  * - 'D[234]' Same as 'd' but for a struct file
2354  * - 'g' For block_device name (gendisk + partition number)
2355  * - 't[RT][dt][r][s]' For time and date as represented by:
2356  *      R    struct rtc_time
2357  *      T    time64_t
2358  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2359  *       (legacy clock framework) of the clock
2360  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2361  *        (legacy clock framework) of the clock
2362  * - 'G' For flags to be printed as a collection of symbolic strings that would
2363  *       construct the specific value. Supported flags given by option:
2364  *       p page flags (see struct page) given as pointer to unsigned long
2365  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2366  *       v vma flags (VM_*) given as pointer to unsigned long
2367  * - 'OF[fnpPcCF]'  For a device tree object
2368  *                  Without any optional arguments prints the full_name
2369  *                  f device node full_name
2370  *                  n device node name
2371  *                  p device node phandle
2372  *                  P device node path spec (name + @unit)
2373  *                  F device node flags
2374  *                  c major compatible string
2375  *                  C full compatible string
2376  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2377  *		Without an option prints the full name of the node
2378  *		f full name
2379  *		P node name, including a possible unit address
2380  * - 'x' For printing the address unmodified. Equivalent to "%lx".
2381  *       Please read the documentation (path below) before using!
2382  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2383  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2384  *           or user (u) memory to probe, and:
2385  *              s a string, equivalent to "%s" on direct vsnprintf() use
2386  *
2387  * ** When making changes please also update:
2388  *	Documentation/core-api/printk-formats.rst
2389  *
2390  * Note: The default behaviour (unadorned %p) is to hash the address,
2391  * rendering it useful as a unique identifier.
2392  */
2393 static noinline_for_stack
2394 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2395 	      struct printf_spec spec)
2396 {
2397 	switch (*fmt) {
2398 	case 'S':
2399 	case 's':
2400 		ptr = dereference_symbol_descriptor(ptr);
2401 		fallthrough;
2402 	case 'B':
2403 		return symbol_string(buf, end, ptr, spec, fmt);
2404 	case 'R':
2405 	case 'r':
2406 		return resource_string(buf, end, ptr, spec, fmt);
2407 	case 'h':
2408 		return hex_string(buf, end, ptr, spec, fmt);
2409 	case 'b':
2410 		switch (fmt[1]) {
2411 		case 'l':
2412 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2413 		default:
2414 			return bitmap_string(buf, end, ptr, spec, fmt);
2415 		}
2416 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2417 	case 'm':			/* Contiguous: 000102030405 */
2418 					/* [mM]F (FDDI) */
2419 					/* [mM]R (Reverse order; Bluetooth) */
2420 		return mac_address_string(buf, end, ptr, spec, fmt);
2421 	case 'I':			/* Formatted IP supported
2422 					 * 4:	1.2.3.4
2423 					 * 6:	0001:0203:...:0708
2424 					 * 6c:	1::708 or 1::1.2.3.4
2425 					 */
2426 	case 'i':			/* Contiguous:
2427 					 * 4:	001.002.003.004
2428 					 * 6:   000102...0f
2429 					 */
2430 		return ip_addr_string(buf, end, ptr, spec, fmt);
2431 	case 'E':
2432 		return escaped_string(buf, end, ptr, spec, fmt);
2433 	case 'U':
2434 		return uuid_string(buf, end, ptr, spec, fmt);
2435 	case 'V':
2436 		return va_format(buf, end, ptr, spec, fmt);
2437 	case 'K':
2438 		return restricted_pointer(buf, end, ptr, spec);
2439 	case 'N':
2440 		return netdev_bits(buf, end, ptr, spec, fmt);
2441 	case '4':
2442 		return fourcc_string(buf, end, ptr, spec, fmt);
2443 	case 'a':
2444 		return address_val(buf, end, ptr, spec, fmt);
2445 	case 'd':
2446 		return dentry_name(buf, end, ptr, spec, fmt);
2447 	case 't':
2448 		return time_and_date(buf, end, ptr, spec, fmt);
2449 	case 'C':
2450 		return clock(buf, end, ptr, spec, fmt);
2451 	case 'D':
2452 		return file_dentry_name(buf, end, ptr, spec, fmt);
2453 #ifdef CONFIG_BLOCK
2454 	case 'g':
2455 		return bdev_name(buf, end, ptr, spec, fmt);
2456 #endif
2457 
2458 	case 'G':
2459 		return flags_string(buf, end, ptr, spec, fmt);
2460 	case 'O':
2461 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2462 	case 'f':
2463 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2464 	case 'x':
2465 		return pointer_string(buf, end, ptr, spec);
2466 	case 'e':
2467 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2468 		if (!IS_ERR(ptr))
2469 			break;
2470 		return err_ptr(buf, end, ptr, spec);
2471 	case 'u':
2472 	case 'k':
2473 		switch (fmt[1]) {
2474 		case 's':
2475 			return string(buf, end, ptr, spec);
2476 		default:
2477 			return error_string(buf, end, "(einval)", spec);
2478 		}
2479 	}
2480 
2481 	/*
2482 	 * default is to _not_ leak addresses, so hash before printing,
2483 	 * unless no_hash_pointers is specified on the command line.
2484 	 */
2485 	if (unlikely(no_hash_pointers))
2486 		return pointer_string(buf, end, ptr, spec);
2487 	else
2488 		return ptr_to_id(buf, end, ptr, spec);
2489 }
2490 
2491 /*
2492  * Helper function to decode printf style format.
2493  * Each call decode a token from the format and return the
2494  * number of characters read (or likely the delta where it wants
2495  * to go on the next call).
2496  * The decoded token is returned through the parameters
2497  *
2498  * 'h', 'l', or 'L' for integer fields
2499  * 'z' support added 23/7/1999 S.H.
2500  * 'z' changed to 'Z' --davidm 1/25/99
2501  * 'Z' changed to 'z' --adobriyan 2017-01-25
2502  * 't' added for ptrdiff_t
2503  *
2504  * @fmt: the format string
2505  * @type of the token returned
2506  * @flags: various flags such as +, -, # tokens..
2507  * @field_width: overwritten width
2508  * @base: base of the number (octal, hex, ...)
2509  * @precision: precision of a number
2510  * @qualifier: qualifier of a number (long, size_t, ...)
2511  */
2512 static noinline_for_stack
2513 int format_decode(const char *fmt, struct printf_spec *spec)
2514 {
2515 	const char *start = fmt;
2516 	char qualifier;
2517 
2518 	/* we finished early by reading the field width */
2519 	if (spec->type == FORMAT_TYPE_WIDTH) {
2520 		if (spec->field_width < 0) {
2521 			spec->field_width = -spec->field_width;
2522 			spec->flags |= LEFT;
2523 		}
2524 		spec->type = FORMAT_TYPE_NONE;
2525 		goto precision;
2526 	}
2527 
2528 	/* we finished early by reading the precision */
2529 	if (spec->type == FORMAT_TYPE_PRECISION) {
2530 		if (spec->precision < 0)
2531 			spec->precision = 0;
2532 
2533 		spec->type = FORMAT_TYPE_NONE;
2534 		goto qualifier;
2535 	}
2536 
2537 	/* By default */
2538 	spec->type = FORMAT_TYPE_NONE;
2539 
2540 	for (; *fmt ; ++fmt) {
2541 		if (*fmt == '%')
2542 			break;
2543 	}
2544 
2545 	/* Return the current non-format string */
2546 	if (fmt != start || !*fmt)
2547 		return fmt - start;
2548 
2549 	/* Process flags */
2550 	spec->flags = 0;
2551 
2552 	while (1) { /* this also skips first '%' */
2553 		bool found = true;
2554 
2555 		++fmt;
2556 
2557 		switch (*fmt) {
2558 		case '-': spec->flags |= LEFT;    break;
2559 		case '+': spec->flags |= PLUS;    break;
2560 		case ' ': spec->flags |= SPACE;   break;
2561 		case '#': spec->flags |= SPECIAL; break;
2562 		case '0': spec->flags |= ZEROPAD; break;
2563 		default:  found = false;
2564 		}
2565 
2566 		if (!found)
2567 			break;
2568 	}
2569 
2570 	/* get field width */
2571 	spec->field_width = -1;
2572 
2573 	if (isdigit(*fmt))
2574 		spec->field_width = skip_atoi(&fmt);
2575 	else if (*fmt == '*') {
2576 		/* it's the next argument */
2577 		spec->type = FORMAT_TYPE_WIDTH;
2578 		return ++fmt - start;
2579 	}
2580 
2581 precision:
2582 	/* get the precision */
2583 	spec->precision = -1;
2584 	if (*fmt == '.') {
2585 		++fmt;
2586 		if (isdigit(*fmt)) {
2587 			spec->precision = skip_atoi(&fmt);
2588 			if (spec->precision < 0)
2589 				spec->precision = 0;
2590 		} else if (*fmt == '*') {
2591 			/* it's the next argument */
2592 			spec->type = FORMAT_TYPE_PRECISION;
2593 			return ++fmt - start;
2594 		}
2595 	}
2596 
2597 qualifier:
2598 	/* get the conversion qualifier */
2599 	qualifier = 0;
2600 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2601 	    *fmt == 'z' || *fmt == 't') {
2602 		qualifier = *fmt++;
2603 		if (unlikely(qualifier == *fmt)) {
2604 			if (qualifier == 'l') {
2605 				qualifier = 'L';
2606 				++fmt;
2607 			} else if (qualifier == 'h') {
2608 				qualifier = 'H';
2609 				++fmt;
2610 			}
2611 		}
2612 	}
2613 
2614 	/* default base */
2615 	spec->base = 10;
2616 	switch (*fmt) {
2617 	case 'c':
2618 		spec->type = FORMAT_TYPE_CHAR;
2619 		return ++fmt - start;
2620 
2621 	case 's':
2622 		spec->type = FORMAT_TYPE_STR;
2623 		return ++fmt - start;
2624 
2625 	case 'p':
2626 		spec->type = FORMAT_TYPE_PTR;
2627 		return ++fmt - start;
2628 
2629 	case '%':
2630 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2631 		return ++fmt - start;
2632 
2633 	/* integer number formats - set up the flags and "break" */
2634 	case 'o':
2635 		spec->base = 8;
2636 		break;
2637 
2638 	case 'x':
2639 		spec->flags |= SMALL;
2640 		fallthrough;
2641 
2642 	case 'X':
2643 		spec->base = 16;
2644 		break;
2645 
2646 	case 'd':
2647 	case 'i':
2648 		spec->flags |= SIGN;
2649 		break;
2650 	case 'u':
2651 		break;
2652 
2653 	case 'n':
2654 		/*
2655 		 * Since %n poses a greater security risk than
2656 		 * utility, treat it as any other invalid or
2657 		 * unsupported format specifier.
2658 		 */
2659 		fallthrough;
2660 
2661 	default:
2662 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2663 		spec->type = FORMAT_TYPE_INVALID;
2664 		return fmt - start;
2665 	}
2666 
2667 	if (qualifier == 'L')
2668 		spec->type = FORMAT_TYPE_LONG_LONG;
2669 	else if (qualifier == 'l') {
2670 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2671 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2672 	} else if (qualifier == 'z') {
2673 		spec->type = FORMAT_TYPE_SIZE_T;
2674 	} else if (qualifier == 't') {
2675 		spec->type = FORMAT_TYPE_PTRDIFF;
2676 	} else if (qualifier == 'H') {
2677 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2678 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2679 	} else if (qualifier == 'h') {
2680 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2681 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2682 	} else {
2683 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2684 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2685 	}
2686 
2687 	return ++fmt - start;
2688 }
2689 
2690 static void
2691 set_field_width(struct printf_spec *spec, int width)
2692 {
2693 	spec->field_width = width;
2694 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2695 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2696 	}
2697 }
2698 
2699 static void
2700 set_precision(struct printf_spec *spec, int prec)
2701 {
2702 	spec->precision = prec;
2703 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2704 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2705 	}
2706 }
2707 
2708 /**
2709  * vsnprintf - Format a string and place it in a buffer
2710  * @buf: The buffer to place the result into
2711  * @size: The size of the buffer, including the trailing null space
2712  * @fmt: The format string to use
2713  * @args: Arguments for the format string
2714  *
2715  * This function generally follows C99 vsnprintf, but has some
2716  * extensions and a few limitations:
2717  *
2718  *  - ``%n`` is unsupported
2719  *  - ``%p*`` is handled by pointer()
2720  *
2721  * See pointer() or Documentation/core-api/printk-formats.rst for more
2722  * extensive description.
2723  *
2724  * **Please update the documentation in both places when making changes**
2725  *
2726  * The return value is the number of characters which would
2727  * be generated for the given input, excluding the trailing
2728  * '\0', as per ISO C99. If you want to have the exact
2729  * number of characters written into @buf as return value
2730  * (not including the trailing '\0'), use vscnprintf(). If the
2731  * return is greater than or equal to @size, the resulting
2732  * string is truncated.
2733  *
2734  * If you're not already dealing with a va_list consider using snprintf().
2735  */
2736 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2737 {
2738 	unsigned long long num;
2739 	char *str, *end;
2740 	struct printf_spec spec = {0};
2741 
2742 	/* Reject out-of-range values early.  Large positive sizes are
2743 	   used for unknown buffer sizes. */
2744 	if (WARN_ON_ONCE(size > INT_MAX))
2745 		return 0;
2746 
2747 	str = buf;
2748 	end = buf + size;
2749 
2750 	/* Make sure end is always >= buf */
2751 	if (end < buf) {
2752 		end = ((void *)-1);
2753 		size = end - buf;
2754 	}
2755 
2756 	while (*fmt) {
2757 		const char *old_fmt = fmt;
2758 		int read = format_decode(fmt, &spec);
2759 
2760 		fmt += read;
2761 
2762 		switch (spec.type) {
2763 		case FORMAT_TYPE_NONE: {
2764 			int copy = read;
2765 			if (str < end) {
2766 				if (copy > end - str)
2767 					copy = end - str;
2768 				memcpy(str, old_fmt, copy);
2769 			}
2770 			str += read;
2771 			break;
2772 		}
2773 
2774 		case FORMAT_TYPE_WIDTH:
2775 			set_field_width(&spec, va_arg(args, int));
2776 			break;
2777 
2778 		case FORMAT_TYPE_PRECISION:
2779 			set_precision(&spec, va_arg(args, int));
2780 			break;
2781 
2782 		case FORMAT_TYPE_CHAR: {
2783 			char c;
2784 
2785 			if (!(spec.flags & LEFT)) {
2786 				while (--spec.field_width > 0) {
2787 					if (str < end)
2788 						*str = ' ';
2789 					++str;
2790 
2791 				}
2792 			}
2793 			c = (unsigned char) va_arg(args, int);
2794 			if (str < end)
2795 				*str = c;
2796 			++str;
2797 			while (--spec.field_width > 0) {
2798 				if (str < end)
2799 					*str = ' ';
2800 				++str;
2801 			}
2802 			break;
2803 		}
2804 
2805 		case FORMAT_TYPE_STR:
2806 			str = string(str, end, va_arg(args, char *), spec);
2807 			break;
2808 
2809 		case FORMAT_TYPE_PTR:
2810 			str = pointer(fmt, str, end, va_arg(args, void *),
2811 				      spec);
2812 			while (isalnum(*fmt))
2813 				fmt++;
2814 			break;
2815 
2816 		case FORMAT_TYPE_PERCENT_CHAR:
2817 			if (str < end)
2818 				*str = '%';
2819 			++str;
2820 			break;
2821 
2822 		case FORMAT_TYPE_INVALID:
2823 			/*
2824 			 * Presumably the arguments passed gcc's type
2825 			 * checking, but there is no safe or sane way
2826 			 * for us to continue parsing the format and
2827 			 * fetching from the va_list; the remaining
2828 			 * specifiers and arguments would be out of
2829 			 * sync.
2830 			 */
2831 			goto out;
2832 
2833 		default:
2834 			switch (spec.type) {
2835 			case FORMAT_TYPE_LONG_LONG:
2836 				num = va_arg(args, long long);
2837 				break;
2838 			case FORMAT_TYPE_ULONG:
2839 				num = va_arg(args, unsigned long);
2840 				break;
2841 			case FORMAT_TYPE_LONG:
2842 				num = va_arg(args, long);
2843 				break;
2844 			case FORMAT_TYPE_SIZE_T:
2845 				if (spec.flags & SIGN)
2846 					num = va_arg(args, ssize_t);
2847 				else
2848 					num = va_arg(args, size_t);
2849 				break;
2850 			case FORMAT_TYPE_PTRDIFF:
2851 				num = va_arg(args, ptrdiff_t);
2852 				break;
2853 			case FORMAT_TYPE_UBYTE:
2854 				num = (unsigned char) va_arg(args, int);
2855 				break;
2856 			case FORMAT_TYPE_BYTE:
2857 				num = (signed char) va_arg(args, int);
2858 				break;
2859 			case FORMAT_TYPE_USHORT:
2860 				num = (unsigned short) va_arg(args, int);
2861 				break;
2862 			case FORMAT_TYPE_SHORT:
2863 				num = (short) va_arg(args, int);
2864 				break;
2865 			case FORMAT_TYPE_INT:
2866 				num = (int) va_arg(args, int);
2867 				break;
2868 			default:
2869 				num = va_arg(args, unsigned int);
2870 			}
2871 
2872 			str = number(str, end, num, spec);
2873 		}
2874 	}
2875 
2876 out:
2877 	if (size > 0) {
2878 		if (str < end)
2879 			*str = '\0';
2880 		else
2881 			end[-1] = '\0';
2882 	}
2883 
2884 	/* the trailing null byte doesn't count towards the total */
2885 	return str-buf;
2886 
2887 }
2888 EXPORT_SYMBOL(vsnprintf);
2889 
2890 /**
2891  * vscnprintf - Format a string and place it in a buffer
2892  * @buf: The buffer to place the result into
2893  * @size: The size of the buffer, including the trailing null space
2894  * @fmt: The format string to use
2895  * @args: Arguments for the format string
2896  *
2897  * The return value is the number of characters which have been written into
2898  * the @buf not including the trailing '\0'. If @size is == 0 the function
2899  * returns 0.
2900  *
2901  * If you're not already dealing with a va_list consider using scnprintf().
2902  *
2903  * See the vsnprintf() documentation for format string extensions over C99.
2904  */
2905 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2906 {
2907 	int i;
2908 
2909 	i = vsnprintf(buf, size, fmt, args);
2910 
2911 	if (likely(i < size))
2912 		return i;
2913 	if (size != 0)
2914 		return size - 1;
2915 	return 0;
2916 }
2917 EXPORT_SYMBOL(vscnprintf);
2918 
2919 /**
2920  * snprintf - Format a string and place it in a buffer
2921  * @buf: The buffer to place the result into
2922  * @size: The size of the buffer, including the trailing null space
2923  * @fmt: The format string to use
2924  * @...: Arguments for the format string
2925  *
2926  * The return value is the number of characters which would be
2927  * generated for the given input, excluding the trailing null,
2928  * as per ISO C99.  If the return is greater than or equal to
2929  * @size, the resulting string is truncated.
2930  *
2931  * See the vsnprintf() documentation for format string extensions over C99.
2932  */
2933 int snprintf(char *buf, size_t size, const char *fmt, ...)
2934 {
2935 	va_list args;
2936 	int i;
2937 
2938 	va_start(args, fmt);
2939 	i = vsnprintf(buf, size, fmt, args);
2940 	va_end(args);
2941 
2942 	return i;
2943 }
2944 EXPORT_SYMBOL(snprintf);
2945 
2946 /**
2947  * scnprintf - Format a string and place it in a buffer
2948  * @buf: The buffer to place the result into
2949  * @size: The size of the buffer, including the trailing null space
2950  * @fmt: The format string to use
2951  * @...: Arguments for the format string
2952  *
2953  * The return value is the number of characters written into @buf not including
2954  * the trailing '\0'. If @size is == 0 the function returns 0.
2955  */
2956 
2957 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2958 {
2959 	va_list args;
2960 	int i;
2961 
2962 	va_start(args, fmt);
2963 	i = vscnprintf(buf, size, fmt, args);
2964 	va_end(args);
2965 
2966 	return i;
2967 }
2968 EXPORT_SYMBOL(scnprintf);
2969 
2970 /**
2971  * vsprintf - Format a string and place it in a buffer
2972  * @buf: The buffer to place the result into
2973  * @fmt: The format string to use
2974  * @args: Arguments for the format string
2975  *
2976  * The function returns the number of characters written
2977  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2978  * buffer overflows.
2979  *
2980  * If you're not already dealing with a va_list consider using sprintf().
2981  *
2982  * See the vsnprintf() documentation for format string extensions over C99.
2983  */
2984 int vsprintf(char *buf, const char *fmt, va_list args)
2985 {
2986 	return vsnprintf(buf, INT_MAX, fmt, args);
2987 }
2988 EXPORT_SYMBOL(vsprintf);
2989 
2990 /**
2991  * sprintf - Format a string and place it in a buffer
2992  * @buf: The buffer to place the result into
2993  * @fmt: The format string to use
2994  * @...: Arguments for the format string
2995  *
2996  * The function returns the number of characters written
2997  * into @buf. Use snprintf() or scnprintf() in order to avoid
2998  * buffer overflows.
2999  *
3000  * See the vsnprintf() documentation for format string extensions over C99.
3001  */
3002 int sprintf(char *buf, const char *fmt, ...)
3003 {
3004 	va_list args;
3005 	int i;
3006 
3007 	va_start(args, fmt);
3008 	i = vsnprintf(buf, INT_MAX, fmt, args);
3009 	va_end(args);
3010 
3011 	return i;
3012 }
3013 EXPORT_SYMBOL(sprintf);
3014 
3015 #ifdef CONFIG_BINARY_PRINTF
3016 /*
3017  * bprintf service:
3018  * vbin_printf() - VA arguments to binary data
3019  * bstr_printf() - Binary data to text string
3020  */
3021 
3022 /**
3023  * vbin_printf - Parse a format string and place args' binary value in a buffer
3024  * @bin_buf: The buffer to place args' binary value
3025  * @size: The size of the buffer(by words(32bits), not characters)
3026  * @fmt: The format string to use
3027  * @args: Arguments for the format string
3028  *
3029  * The format follows C99 vsnprintf, except %n is ignored, and its argument
3030  * is skipped.
3031  *
3032  * The return value is the number of words(32bits) which would be generated for
3033  * the given input.
3034  *
3035  * NOTE:
3036  * If the return value is greater than @size, the resulting bin_buf is NOT
3037  * valid for bstr_printf().
3038  */
3039 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3040 {
3041 	struct printf_spec spec = {0};
3042 	char *str, *end;
3043 	int width;
3044 
3045 	str = (char *)bin_buf;
3046 	end = (char *)(bin_buf + size);
3047 
3048 #define save_arg(type)							\
3049 ({									\
3050 	unsigned long long value;					\
3051 	if (sizeof(type) == 8) {					\
3052 		unsigned long long val8;				\
3053 		str = PTR_ALIGN(str, sizeof(u32));			\
3054 		val8 = va_arg(args, unsigned long long);		\
3055 		if (str + sizeof(type) <= end) {			\
3056 			*(u32 *)str = *(u32 *)&val8;			\
3057 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
3058 		}							\
3059 		value = val8;						\
3060 	} else {							\
3061 		unsigned int val4;					\
3062 		str = PTR_ALIGN(str, sizeof(type));			\
3063 		val4 = va_arg(args, int);				\
3064 		if (str + sizeof(type) <= end)				\
3065 			*(typeof(type) *)str = (type)(long)val4;	\
3066 		value = (unsigned long long)val4;			\
3067 	}								\
3068 	str += sizeof(type);						\
3069 	value;								\
3070 })
3071 
3072 	while (*fmt) {
3073 		int read = format_decode(fmt, &spec);
3074 
3075 		fmt += read;
3076 
3077 		switch (spec.type) {
3078 		case FORMAT_TYPE_NONE:
3079 		case FORMAT_TYPE_PERCENT_CHAR:
3080 			break;
3081 		case FORMAT_TYPE_INVALID:
3082 			goto out;
3083 
3084 		case FORMAT_TYPE_WIDTH:
3085 		case FORMAT_TYPE_PRECISION:
3086 			width = (int)save_arg(int);
3087 			/* Pointers may require the width */
3088 			if (*fmt == 'p')
3089 				set_field_width(&spec, width);
3090 			break;
3091 
3092 		case FORMAT_TYPE_CHAR:
3093 			save_arg(char);
3094 			break;
3095 
3096 		case FORMAT_TYPE_STR: {
3097 			const char *save_str = va_arg(args, char *);
3098 			const char *err_msg;
3099 			size_t len;
3100 
3101 			err_msg = check_pointer_msg(save_str);
3102 			if (err_msg)
3103 				save_str = err_msg;
3104 
3105 			len = strlen(save_str) + 1;
3106 			if (str + len < end)
3107 				memcpy(str, save_str, len);
3108 			str += len;
3109 			break;
3110 		}
3111 
3112 		case FORMAT_TYPE_PTR:
3113 			/* Dereferenced pointers must be done now */
3114 			switch (*fmt) {
3115 			/* Dereference of functions is still OK */
3116 			case 'S':
3117 			case 's':
3118 			case 'x':
3119 			case 'K':
3120 			case 'e':
3121 				save_arg(void *);
3122 				break;
3123 			default:
3124 				if (!isalnum(*fmt)) {
3125 					save_arg(void *);
3126 					break;
3127 				}
3128 				str = pointer(fmt, str, end, va_arg(args, void *),
3129 					      spec);
3130 				if (str + 1 < end)
3131 					*str++ = '\0';
3132 				else
3133 					end[-1] = '\0'; /* Must be nul terminated */
3134 			}
3135 			/* skip all alphanumeric pointer suffixes */
3136 			while (isalnum(*fmt))
3137 				fmt++;
3138 			break;
3139 
3140 		default:
3141 			switch (spec.type) {
3142 
3143 			case FORMAT_TYPE_LONG_LONG:
3144 				save_arg(long long);
3145 				break;
3146 			case FORMAT_TYPE_ULONG:
3147 			case FORMAT_TYPE_LONG:
3148 				save_arg(unsigned long);
3149 				break;
3150 			case FORMAT_TYPE_SIZE_T:
3151 				save_arg(size_t);
3152 				break;
3153 			case FORMAT_TYPE_PTRDIFF:
3154 				save_arg(ptrdiff_t);
3155 				break;
3156 			case FORMAT_TYPE_UBYTE:
3157 			case FORMAT_TYPE_BYTE:
3158 				save_arg(char);
3159 				break;
3160 			case FORMAT_TYPE_USHORT:
3161 			case FORMAT_TYPE_SHORT:
3162 				save_arg(short);
3163 				break;
3164 			default:
3165 				save_arg(int);
3166 			}
3167 		}
3168 	}
3169 
3170 out:
3171 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3172 #undef save_arg
3173 }
3174 EXPORT_SYMBOL_GPL(vbin_printf);
3175 
3176 /**
3177  * bstr_printf - Format a string from binary arguments and place it in a buffer
3178  * @buf: The buffer to place the result into
3179  * @size: The size of the buffer, including the trailing null space
3180  * @fmt: The format string to use
3181  * @bin_buf: Binary arguments for the format string
3182  *
3183  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3184  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3185  * a binary buffer that generated by vbin_printf.
3186  *
3187  * The format follows C99 vsnprintf, but has some extensions:
3188  *  see vsnprintf comment for details.
3189  *
3190  * The return value is the number of characters which would
3191  * be generated for the given input, excluding the trailing
3192  * '\0', as per ISO C99. If you want to have the exact
3193  * number of characters written into @buf as return value
3194  * (not including the trailing '\0'), use vscnprintf(). If the
3195  * return is greater than or equal to @size, the resulting
3196  * string is truncated.
3197  */
3198 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3199 {
3200 	struct printf_spec spec = {0};
3201 	char *str, *end;
3202 	const char *args = (const char *)bin_buf;
3203 
3204 	if (WARN_ON_ONCE(size > INT_MAX))
3205 		return 0;
3206 
3207 	str = buf;
3208 	end = buf + size;
3209 
3210 #define get_arg(type)							\
3211 ({									\
3212 	typeof(type) value;						\
3213 	if (sizeof(type) == 8) {					\
3214 		args = PTR_ALIGN(args, sizeof(u32));			\
3215 		*(u32 *)&value = *(u32 *)args;				\
3216 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3217 	} else {							\
3218 		args = PTR_ALIGN(args, sizeof(type));			\
3219 		value = *(typeof(type) *)args;				\
3220 	}								\
3221 	args += sizeof(type);						\
3222 	value;								\
3223 })
3224 
3225 	/* Make sure end is always >= buf */
3226 	if (end < buf) {
3227 		end = ((void *)-1);
3228 		size = end - buf;
3229 	}
3230 
3231 	while (*fmt) {
3232 		const char *old_fmt = fmt;
3233 		int read = format_decode(fmt, &spec);
3234 
3235 		fmt += read;
3236 
3237 		switch (spec.type) {
3238 		case FORMAT_TYPE_NONE: {
3239 			int copy = read;
3240 			if (str < end) {
3241 				if (copy > end - str)
3242 					copy = end - str;
3243 				memcpy(str, old_fmt, copy);
3244 			}
3245 			str += read;
3246 			break;
3247 		}
3248 
3249 		case FORMAT_TYPE_WIDTH:
3250 			set_field_width(&spec, get_arg(int));
3251 			break;
3252 
3253 		case FORMAT_TYPE_PRECISION:
3254 			set_precision(&spec, get_arg(int));
3255 			break;
3256 
3257 		case FORMAT_TYPE_CHAR: {
3258 			char c;
3259 
3260 			if (!(spec.flags & LEFT)) {
3261 				while (--spec.field_width > 0) {
3262 					if (str < end)
3263 						*str = ' ';
3264 					++str;
3265 				}
3266 			}
3267 			c = (unsigned char) get_arg(char);
3268 			if (str < end)
3269 				*str = c;
3270 			++str;
3271 			while (--spec.field_width > 0) {
3272 				if (str < end)
3273 					*str = ' ';
3274 				++str;
3275 			}
3276 			break;
3277 		}
3278 
3279 		case FORMAT_TYPE_STR: {
3280 			const char *str_arg = args;
3281 			args += strlen(str_arg) + 1;
3282 			str = string(str, end, (char *)str_arg, spec);
3283 			break;
3284 		}
3285 
3286 		case FORMAT_TYPE_PTR: {
3287 			bool process = false;
3288 			int copy, len;
3289 			/* Non function dereferences were already done */
3290 			switch (*fmt) {
3291 			case 'S':
3292 			case 's':
3293 			case 'x':
3294 			case 'K':
3295 			case 'e':
3296 				process = true;
3297 				break;
3298 			default:
3299 				if (!isalnum(*fmt)) {
3300 					process = true;
3301 					break;
3302 				}
3303 				/* Pointer dereference was already processed */
3304 				if (str < end) {
3305 					len = copy = strlen(args);
3306 					if (copy > end - str)
3307 						copy = end - str;
3308 					memcpy(str, args, copy);
3309 					str += len;
3310 					args += len + 1;
3311 				}
3312 			}
3313 			if (process)
3314 				str = pointer(fmt, str, end, get_arg(void *), spec);
3315 
3316 			while (isalnum(*fmt))
3317 				fmt++;
3318 			break;
3319 		}
3320 
3321 		case FORMAT_TYPE_PERCENT_CHAR:
3322 			if (str < end)
3323 				*str = '%';
3324 			++str;
3325 			break;
3326 
3327 		case FORMAT_TYPE_INVALID:
3328 			goto out;
3329 
3330 		default: {
3331 			unsigned long long num;
3332 
3333 			switch (spec.type) {
3334 
3335 			case FORMAT_TYPE_LONG_LONG:
3336 				num = get_arg(long long);
3337 				break;
3338 			case FORMAT_TYPE_ULONG:
3339 			case FORMAT_TYPE_LONG:
3340 				num = get_arg(unsigned long);
3341 				break;
3342 			case FORMAT_TYPE_SIZE_T:
3343 				num = get_arg(size_t);
3344 				break;
3345 			case FORMAT_TYPE_PTRDIFF:
3346 				num = get_arg(ptrdiff_t);
3347 				break;
3348 			case FORMAT_TYPE_UBYTE:
3349 				num = get_arg(unsigned char);
3350 				break;
3351 			case FORMAT_TYPE_BYTE:
3352 				num = get_arg(signed char);
3353 				break;
3354 			case FORMAT_TYPE_USHORT:
3355 				num = get_arg(unsigned short);
3356 				break;
3357 			case FORMAT_TYPE_SHORT:
3358 				num = get_arg(short);
3359 				break;
3360 			case FORMAT_TYPE_UINT:
3361 				num = get_arg(unsigned int);
3362 				break;
3363 			default:
3364 				num = get_arg(int);
3365 			}
3366 
3367 			str = number(str, end, num, spec);
3368 		} /* default: */
3369 		} /* switch(spec.type) */
3370 	} /* while(*fmt) */
3371 
3372 out:
3373 	if (size > 0) {
3374 		if (str < end)
3375 			*str = '\0';
3376 		else
3377 			end[-1] = '\0';
3378 	}
3379 
3380 #undef get_arg
3381 
3382 	/* the trailing null byte doesn't count towards the total */
3383 	return str - buf;
3384 }
3385 EXPORT_SYMBOL_GPL(bstr_printf);
3386 
3387 /**
3388  * bprintf - Parse a format string and place args' binary value in a buffer
3389  * @bin_buf: The buffer to place args' binary value
3390  * @size: The size of the buffer(by words(32bits), not characters)
3391  * @fmt: The format string to use
3392  * @...: Arguments for the format string
3393  *
3394  * The function returns the number of words(u32) written
3395  * into @bin_buf.
3396  */
3397 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3398 {
3399 	va_list args;
3400 	int ret;
3401 
3402 	va_start(args, fmt);
3403 	ret = vbin_printf(bin_buf, size, fmt, args);
3404 	va_end(args);
3405 
3406 	return ret;
3407 }
3408 EXPORT_SYMBOL_GPL(bprintf);
3409 
3410 #endif /* CONFIG_BINARY_PRINTF */
3411 
3412 /**
3413  * vsscanf - Unformat a buffer into a list of arguments
3414  * @buf:	input buffer
3415  * @fmt:	format of buffer
3416  * @args:	arguments
3417  */
3418 int vsscanf(const char *buf, const char *fmt, va_list args)
3419 {
3420 	const char *str = buf;
3421 	char *next;
3422 	char digit;
3423 	int num = 0;
3424 	u8 qualifier;
3425 	unsigned int base;
3426 	union {
3427 		long long s;
3428 		unsigned long long u;
3429 	} val;
3430 	s16 field_width;
3431 	bool is_sign;
3432 
3433 	while (*fmt) {
3434 		/* skip any white space in format */
3435 		/* white space in format matches any amount of
3436 		 * white space, including none, in the input.
3437 		 */
3438 		if (isspace(*fmt)) {
3439 			fmt = skip_spaces(++fmt);
3440 			str = skip_spaces(str);
3441 		}
3442 
3443 		/* anything that is not a conversion must match exactly */
3444 		if (*fmt != '%' && *fmt) {
3445 			if (*fmt++ != *str++)
3446 				break;
3447 			continue;
3448 		}
3449 
3450 		if (!*fmt)
3451 			break;
3452 		++fmt;
3453 
3454 		/* skip this conversion.
3455 		 * advance both strings to next white space
3456 		 */
3457 		if (*fmt == '*') {
3458 			if (!*str)
3459 				break;
3460 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3461 				/* '%*[' not yet supported, invalid format */
3462 				if (*fmt == '[')
3463 					return num;
3464 				fmt++;
3465 			}
3466 			while (!isspace(*str) && *str)
3467 				str++;
3468 			continue;
3469 		}
3470 
3471 		/* get field width */
3472 		field_width = -1;
3473 		if (isdigit(*fmt)) {
3474 			field_width = skip_atoi(&fmt);
3475 			if (field_width <= 0)
3476 				break;
3477 		}
3478 
3479 		/* get conversion qualifier */
3480 		qualifier = -1;
3481 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3482 		    *fmt == 'z') {
3483 			qualifier = *fmt++;
3484 			if (unlikely(qualifier == *fmt)) {
3485 				if (qualifier == 'h') {
3486 					qualifier = 'H';
3487 					fmt++;
3488 				} else if (qualifier == 'l') {
3489 					qualifier = 'L';
3490 					fmt++;
3491 				}
3492 			}
3493 		}
3494 
3495 		if (!*fmt)
3496 			break;
3497 
3498 		if (*fmt == 'n') {
3499 			/* return number of characters read so far */
3500 			*va_arg(args, int *) = str - buf;
3501 			++fmt;
3502 			continue;
3503 		}
3504 
3505 		if (!*str)
3506 			break;
3507 
3508 		base = 10;
3509 		is_sign = false;
3510 
3511 		switch (*fmt++) {
3512 		case 'c':
3513 		{
3514 			char *s = (char *)va_arg(args, char*);
3515 			if (field_width == -1)
3516 				field_width = 1;
3517 			do {
3518 				*s++ = *str++;
3519 			} while (--field_width > 0 && *str);
3520 			num++;
3521 		}
3522 		continue;
3523 		case 's':
3524 		{
3525 			char *s = (char *)va_arg(args, char *);
3526 			if (field_width == -1)
3527 				field_width = SHRT_MAX;
3528 			/* first, skip leading white space in buffer */
3529 			str = skip_spaces(str);
3530 
3531 			/* now copy until next white space */
3532 			while (*str && !isspace(*str) && field_width--)
3533 				*s++ = *str++;
3534 			*s = '\0';
3535 			num++;
3536 		}
3537 		continue;
3538 		/*
3539 		 * Warning: This implementation of the '[' conversion specifier
3540 		 * deviates from its glibc counterpart in the following ways:
3541 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3542 		 *     character
3543 		 * (2) It cannot match the closing bracket ']' itself
3544 		 * (3) A field width is required
3545 		 * (4) '%*[' (discard matching input) is currently not supported
3546 		 *
3547 		 * Example usage:
3548 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3549 		 *		buf1, buf2, buf3);
3550 		 * if (ret < 3)
3551 		 *    // etc..
3552 		 */
3553 		case '[':
3554 		{
3555 			char *s = (char *)va_arg(args, char *);
3556 			DECLARE_BITMAP(set, 256) = {0};
3557 			unsigned int len = 0;
3558 			bool negate = (*fmt == '^');
3559 
3560 			/* field width is required */
3561 			if (field_width == -1)
3562 				return num;
3563 
3564 			if (negate)
3565 				++fmt;
3566 
3567 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3568 				set_bit((u8)*fmt, set);
3569 
3570 			/* no ']' or no character set found */
3571 			if (!*fmt || !len)
3572 				return num;
3573 			++fmt;
3574 
3575 			if (negate) {
3576 				bitmap_complement(set, set, 256);
3577 				/* exclude null '\0' byte */
3578 				clear_bit(0, set);
3579 			}
3580 
3581 			/* match must be non-empty */
3582 			if (!test_bit((u8)*str, set))
3583 				return num;
3584 
3585 			while (test_bit((u8)*str, set) && field_width--)
3586 				*s++ = *str++;
3587 			*s = '\0';
3588 			++num;
3589 		}
3590 		continue;
3591 		case 'o':
3592 			base = 8;
3593 			break;
3594 		case 'x':
3595 		case 'X':
3596 			base = 16;
3597 			break;
3598 		case 'i':
3599 			base = 0;
3600 			fallthrough;
3601 		case 'd':
3602 			is_sign = true;
3603 			fallthrough;
3604 		case 'u':
3605 			break;
3606 		case '%':
3607 			/* looking for '%' in str */
3608 			if (*str++ != '%')
3609 				return num;
3610 			continue;
3611 		default:
3612 			/* invalid format; stop here */
3613 			return num;
3614 		}
3615 
3616 		/* have some sort of integer conversion.
3617 		 * first, skip white space in buffer.
3618 		 */
3619 		str = skip_spaces(str);
3620 
3621 		digit = *str;
3622 		if (is_sign && digit == '-') {
3623 			if (field_width == 1)
3624 				break;
3625 
3626 			digit = *(str + 1);
3627 		}
3628 
3629 		if (!digit
3630 		    || (base == 16 && !isxdigit(digit))
3631 		    || (base == 10 && !isdigit(digit))
3632 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
3633 		    || (base == 0 && !isdigit(digit)))
3634 			break;
3635 
3636 		if (is_sign)
3637 			val.s = simple_strntoll(str,
3638 						field_width >= 0 ? field_width : INT_MAX,
3639 						&next, base);
3640 		else
3641 			val.u = simple_strntoull(str,
3642 						 field_width >= 0 ? field_width : INT_MAX,
3643 						 &next, base);
3644 
3645 		switch (qualifier) {
3646 		case 'H':	/* that's 'hh' in format */
3647 			if (is_sign)
3648 				*va_arg(args, signed char *) = val.s;
3649 			else
3650 				*va_arg(args, unsigned char *) = val.u;
3651 			break;
3652 		case 'h':
3653 			if (is_sign)
3654 				*va_arg(args, short *) = val.s;
3655 			else
3656 				*va_arg(args, unsigned short *) = val.u;
3657 			break;
3658 		case 'l':
3659 			if (is_sign)
3660 				*va_arg(args, long *) = val.s;
3661 			else
3662 				*va_arg(args, unsigned long *) = val.u;
3663 			break;
3664 		case 'L':
3665 			if (is_sign)
3666 				*va_arg(args, long long *) = val.s;
3667 			else
3668 				*va_arg(args, unsigned long long *) = val.u;
3669 			break;
3670 		case 'z':
3671 			*va_arg(args, size_t *) = val.u;
3672 			break;
3673 		default:
3674 			if (is_sign)
3675 				*va_arg(args, int *) = val.s;
3676 			else
3677 				*va_arg(args, unsigned int *) = val.u;
3678 			break;
3679 		}
3680 		num++;
3681 
3682 		if (!next)
3683 			break;
3684 		str = next;
3685 	}
3686 
3687 	return num;
3688 }
3689 EXPORT_SYMBOL(vsscanf);
3690 
3691 /**
3692  * sscanf - Unformat a buffer into a list of arguments
3693  * @buf:	input buffer
3694  * @fmt:	formatting of buffer
3695  * @...:	resulting arguments
3696  */
3697 int sscanf(const char *buf, const char *fmt, ...)
3698 {
3699 	va_list args;
3700 	int i;
3701 
3702 	va_start(args, fmt);
3703 	i = vsscanf(buf, fmt, args);
3704 	va_end(args);
3705 
3706 	return i;
3707 }
3708 EXPORT_SYMBOL(sscanf);
3709