xref: /linux/lib/vsprintf.c (revision 1ee54195a305fae3955642af8528bdf67496d353)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/lib/vsprintf.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  */
7 
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10  * Wirzenius wrote this portably, Torvalds fucked it up :-)
11  */
12 
13 /*
14  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15  * - changed to provide snprintf and vsnprintf functions
16  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17  * - scnprintf and vscnprintf
18  */
19 
20 #include <stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/uuid.h>
38 #include <linux/of.h>
39 #include <net/addrconf.h>
40 #include <linux/siphash.h>
41 #include <linux/compiler.h>
42 #include <linux/property.h>
43 #ifdef CONFIG_BLOCK
44 #include <linux/blkdev.h>
45 #endif
46 
47 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
48 
49 #include <asm/page.h>		/* for PAGE_SIZE */
50 #include <asm/byteorder.h>	/* cpu_to_le16 */
51 
52 #include <linux/string_helpers.h>
53 #include "kstrtox.h"
54 
55 /**
56  * simple_strtoull - convert a string to an unsigned long long
57  * @cp: The start of the string
58  * @endp: A pointer to the end of the parsed string will be placed here
59  * @base: The number base to use
60  *
61  * This function is obsolete. Please use kstrtoull instead.
62  */
63 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
64 {
65 	unsigned long long result;
66 	unsigned int rv;
67 
68 	cp = _parse_integer_fixup_radix(cp, &base);
69 	rv = _parse_integer(cp, base, &result);
70 	/* FIXME */
71 	cp += (rv & ~KSTRTOX_OVERFLOW);
72 
73 	if (endp)
74 		*endp = (char *)cp;
75 
76 	return result;
77 }
78 EXPORT_SYMBOL(simple_strtoull);
79 
80 /**
81  * simple_strtoul - convert a string to an unsigned long
82  * @cp: The start of the string
83  * @endp: A pointer to the end of the parsed string will be placed here
84  * @base: The number base to use
85  *
86  * This function is obsolete. Please use kstrtoul instead.
87  */
88 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
89 {
90 	return simple_strtoull(cp, endp, base);
91 }
92 EXPORT_SYMBOL(simple_strtoul);
93 
94 /**
95  * simple_strtol - convert a string to a signed long
96  * @cp: The start of the string
97  * @endp: A pointer to the end of the parsed string will be placed here
98  * @base: The number base to use
99  *
100  * This function is obsolete. Please use kstrtol instead.
101  */
102 long simple_strtol(const char *cp, char **endp, unsigned int base)
103 {
104 	if (*cp == '-')
105 		return -simple_strtoul(cp + 1, endp, base);
106 
107 	return simple_strtoul(cp, endp, base);
108 }
109 EXPORT_SYMBOL(simple_strtol);
110 
111 /**
112  * simple_strtoll - convert a string to a signed long long
113  * @cp: The start of the string
114  * @endp: A pointer to the end of the parsed string will be placed here
115  * @base: The number base to use
116  *
117  * This function is obsolete. Please use kstrtoll instead.
118  */
119 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
120 {
121 	if (*cp == '-')
122 		return -simple_strtoull(cp + 1, endp, base);
123 
124 	return simple_strtoull(cp, endp, base);
125 }
126 EXPORT_SYMBOL(simple_strtoll);
127 
128 static noinline_for_stack
129 int skip_atoi(const char **s)
130 {
131 	int i = 0;
132 
133 	do {
134 		i = i*10 + *((*s)++) - '0';
135 	} while (isdigit(**s));
136 
137 	return i;
138 }
139 
140 /*
141  * Decimal conversion is by far the most typical, and is used for
142  * /proc and /sys data. This directly impacts e.g. top performance
143  * with many processes running. We optimize it for speed by emitting
144  * two characters at a time, using a 200 byte lookup table. This
145  * roughly halves the number of multiplications compared to computing
146  * the digits one at a time. Implementation strongly inspired by the
147  * previous version, which in turn used ideas described at
148  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
149  * from the author, Douglas W. Jones).
150  *
151  * It turns out there is precisely one 26 bit fixed-point
152  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
153  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
154  * range happens to be somewhat larger (x <= 1073741898), but that's
155  * irrelevant for our purpose.
156  *
157  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
158  * need a 32x32->64 bit multiply, so we simply use the same constant.
159  *
160  * For dividing a number in the range [100, 10^4-1] by 100, there are
161  * several options. The simplest is (x * 0x147b) >> 19, which is valid
162  * for all x <= 43698.
163  */
164 
165 static const u16 decpair[100] = {
166 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
167 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
168 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
169 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
170 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
171 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
172 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
173 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
174 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
175 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
176 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
177 #undef _
178 };
179 
180 /*
181  * This will print a single '0' even if r == 0, since we would
182  * immediately jump to out_r where two 0s would be written but only
183  * one of them accounted for in buf. This is needed by ip4_string
184  * below. All other callers pass a non-zero value of r.
185 */
186 static noinline_for_stack
187 char *put_dec_trunc8(char *buf, unsigned r)
188 {
189 	unsigned q;
190 
191 	/* 1 <= r < 10^8 */
192 	if (r < 100)
193 		goto out_r;
194 
195 	/* 100 <= r < 10^8 */
196 	q = (r * (u64)0x28f5c29) >> 32;
197 	*((u16 *)buf) = decpair[r - 100*q];
198 	buf += 2;
199 
200 	/* 1 <= q < 10^6 */
201 	if (q < 100)
202 		goto out_q;
203 
204 	/*  100 <= q < 10^6 */
205 	r = (q * (u64)0x28f5c29) >> 32;
206 	*((u16 *)buf) = decpair[q - 100*r];
207 	buf += 2;
208 
209 	/* 1 <= r < 10^4 */
210 	if (r < 100)
211 		goto out_r;
212 
213 	/* 100 <= r < 10^4 */
214 	q = (r * 0x147b) >> 19;
215 	*((u16 *)buf) = decpair[r - 100*q];
216 	buf += 2;
217 out_q:
218 	/* 1 <= q < 100 */
219 	r = q;
220 out_r:
221 	/* 1 <= r < 100 */
222 	*((u16 *)buf) = decpair[r];
223 	buf += r < 10 ? 1 : 2;
224 	return buf;
225 }
226 
227 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
228 static noinline_for_stack
229 char *put_dec_full8(char *buf, unsigned r)
230 {
231 	unsigned q;
232 
233 	/* 0 <= r < 10^8 */
234 	q = (r * (u64)0x28f5c29) >> 32;
235 	*((u16 *)buf) = decpair[r - 100*q];
236 	buf += 2;
237 
238 	/* 0 <= q < 10^6 */
239 	r = (q * (u64)0x28f5c29) >> 32;
240 	*((u16 *)buf) = decpair[q - 100*r];
241 	buf += 2;
242 
243 	/* 0 <= r < 10^4 */
244 	q = (r * 0x147b) >> 19;
245 	*((u16 *)buf) = decpair[r - 100*q];
246 	buf += 2;
247 
248 	/* 0 <= q < 100 */
249 	*((u16 *)buf) = decpair[q];
250 	buf += 2;
251 	return buf;
252 }
253 
254 static noinline_for_stack
255 char *put_dec(char *buf, unsigned long long n)
256 {
257 	if (n >= 100*1000*1000)
258 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
259 	/* 1 <= n <= 1.6e11 */
260 	if (n >= 100*1000*1000)
261 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
262 	/* 1 <= n < 1e8 */
263 	return put_dec_trunc8(buf, n);
264 }
265 
266 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
267 
268 static void
269 put_dec_full4(char *buf, unsigned r)
270 {
271 	unsigned q;
272 
273 	/* 0 <= r < 10^4 */
274 	q = (r * 0x147b) >> 19;
275 	*((u16 *)buf) = decpair[r - 100*q];
276 	buf += 2;
277 	/* 0 <= q < 100 */
278 	*((u16 *)buf) = decpair[q];
279 }
280 
281 /*
282  * Call put_dec_full4 on x % 10000, return x / 10000.
283  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
284  * holds for all x < 1,128,869,999.  The largest value this
285  * helper will ever be asked to convert is 1,125,520,955.
286  * (second call in the put_dec code, assuming n is all-ones).
287  */
288 static noinline_for_stack
289 unsigned put_dec_helper4(char *buf, unsigned x)
290 {
291         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
292 
293         put_dec_full4(buf, x - q * 10000);
294         return q;
295 }
296 
297 /* Based on code by Douglas W. Jones found at
298  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
299  * (with permission from the author).
300  * Performs no 64-bit division and hence should be fast on 32-bit machines.
301  */
302 static
303 char *put_dec(char *buf, unsigned long long n)
304 {
305 	uint32_t d3, d2, d1, q, h;
306 
307 	if (n < 100*1000*1000)
308 		return put_dec_trunc8(buf, n);
309 
310 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
311 	h   = (n >> 32);
312 	d2  = (h      ) & 0xffff;
313 	d3  = (h >> 16); /* implicit "& 0xffff" */
314 
315 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
316 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
317 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
318 	q = put_dec_helper4(buf, q);
319 
320 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
321 	q = put_dec_helper4(buf+4, q);
322 
323 	q += 4749 * d3 + 42 * d2;
324 	q = put_dec_helper4(buf+8, q);
325 
326 	q += 281 * d3;
327 	buf += 12;
328 	if (q)
329 		buf = put_dec_trunc8(buf, q);
330 	else while (buf[-1] == '0')
331 		--buf;
332 
333 	return buf;
334 }
335 
336 #endif
337 
338 /*
339  * Convert passed number to decimal string.
340  * Returns the length of string.  On buffer overflow, returns 0.
341  *
342  * If speed is not important, use snprintf(). It's easy to read the code.
343  */
344 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
345 {
346 	/* put_dec requires 2-byte alignment of the buffer. */
347 	char tmp[sizeof(num) * 3] __aligned(2);
348 	int idx, len;
349 
350 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
351 	if (num <= 9) {
352 		tmp[0] = '0' + num;
353 		len = 1;
354 	} else {
355 		len = put_dec(tmp, num) - tmp;
356 	}
357 
358 	if (len > size || width > size)
359 		return 0;
360 
361 	if (width > len) {
362 		width = width - len;
363 		for (idx = 0; idx < width; idx++)
364 			buf[idx] = ' ';
365 	} else {
366 		width = 0;
367 	}
368 
369 	for (idx = 0; idx < len; ++idx)
370 		buf[idx + width] = tmp[len - idx - 1];
371 
372 	return len + width;
373 }
374 
375 #define SIGN	1		/* unsigned/signed, must be 1 */
376 #define LEFT	2		/* left justified */
377 #define PLUS	4		/* show plus */
378 #define SPACE	8		/* space if plus */
379 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
380 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
381 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
382 
383 enum format_type {
384 	FORMAT_TYPE_NONE, /* Just a string part */
385 	FORMAT_TYPE_WIDTH,
386 	FORMAT_TYPE_PRECISION,
387 	FORMAT_TYPE_CHAR,
388 	FORMAT_TYPE_STR,
389 	FORMAT_TYPE_PTR,
390 	FORMAT_TYPE_PERCENT_CHAR,
391 	FORMAT_TYPE_INVALID,
392 	FORMAT_TYPE_LONG_LONG,
393 	FORMAT_TYPE_ULONG,
394 	FORMAT_TYPE_LONG,
395 	FORMAT_TYPE_UBYTE,
396 	FORMAT_TYPE_BYTE,
397 	FORMAT_TYPE_USHORT,
398 	FORMAT_TYPE_SHORT,
399 	FORMAT_TYPE_UINT,
400 	FORMAT_TYPE_INT,
401 	FORMAT_TYPE_SIZE_T,
402 	FORMAT_TYPE_PTRDIFF
403 };
404 
405 struct printf_spec {
406 	unsigned int	type:8;		/* format_type enum */
407 	signed int	field_width:24;	/* width of output field */
408 	unsigned int	flags:8;	/* flags to number() */
409 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
410 	signed int	precision:16;	/* # of digits/chars */
411 } __packed;
412 static_assert(sizeof(struct printf_spec) == 8);
413 
414 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
415 #define PRECISION_MAX ((1 << 15) - 1)
416 
417 static noinline_for_stack
418 char *number(char *buf, char *end, unsigned long long num,
419 	     struct printf_spec spec)
420 {
421 	/* put_dec requires 2-byte alignment of the buffer. */
422 	char tmp[3 * sizeof(num)] __aligned(2);
423 	char sign;
424 	char locase;
425 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
426 	int i;
427 	bool is_zero = num == 0LL;
428 	int field_width = spec.field_width;
429 	int precision = spec.precision;
430 
431 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
432 	 * produces same digits or (maybe lowercased) letters */
433 	locase = (spec.flags & SMALL);
434 	if (spec.flags & LEFT)
435 		spec.flags &= ~ZEROPAD;
436 	sign = 0;
437 	if (spec.flags & SIGN) {
438 		if ((signed long long)num < 0) {
439 			sign = '-';
440 			num = -(signed long long)num;
441 			field_width--;
442 		} else if (spec.flags & PLUS) {
443 			sign = '+';
444 			field_width--;
445 		} else if (spec.flags & SPACE) {
446 			sign = ' ';
447 			field_width--;
448 		}
449 	}
450 	if (need_pfx) {
451 		if (spec.base == 16)
452 			field_width -= 2;
453 		else if (!is_zero)
454 			field_width--;
455 	}
456 
457 	/* generate full string in tmp[], in reverse order */
458 	i = 0;
459 	if (num < spec.base)
460 		tmp[i++] = hex_asc_upper[num] | locase;
461 	else if (spec.base != 10) { /* 8 or 16 */
462 		int mask = spec.base - 1;
463 		int shift = 3;
464 
465 		if (spec.base == 16)
466 			shift = 4;
467 		do {
468 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
469 			num >>= shift;
470 		} while (num);
471 	} else { /* base 10 */
472 		i = put_dec(tmp, num) - tmp;
473 	}
474 
475 	/* printing 100 using %2d gives "100", not "00" */
476 	if (i > precision)
477 		precision = i;
478 	/* leading space padding */
479 	field_width -= precision;
480 	if (!(spec.flags & (ZEROPAD | LEFT))) {
481 		while (--field_width >= 0) {
482 			if (buf < end)
483 				*buf = ' ';
484 			++buf;
485 		}
486 	}
487 	/* sign */
488 	if (sign) {
489 		if (buf < end)
490 			*buf = sign;
491 		++buf;
492 	}
493 	/* "0x" / "0" prefix */
494 	if (need_pfx) {
495 		if (spec.base == 16 || !is_zero) {
496 			if (buf < end)
497 				*buf = '0';
498 			++buf;
499 		}
500 		if (spec.base == 16) {
501 			if (buf < end)
502 				*buf = ('X' | locase);
503 			++buf;
504 		}
505 	}
506 	/* zero or space padding */
507 	if (!(spec.flags & LEFT)) {
508 		char c = ' ' + (spec.flags & ZEROPAD);
509 		BUILD_BUG_ON(' ' + ZEROPAD != '0');
510 		while (--field_width >= 0) {
511 			if (buf < end)
512 				*buf = c;
513 			++buf;
514 		}
515 	}
516 	/* hmm even more zero padding? */
517 	while (i <= --precision) {
518 		if (buf < end)
519 			*buf = '0';
520 		++buf;
521 	}
522 	/* actual digits of result */
523 	while (--i >= 0) {
524 		if (buf < end)
525 			*buf = tmp[i];
526 		++buf;
527 	}
528 	/* trailing space padding */
529 	while (--field_width >= 0) {
530 		if (buf < end)
531 			*buf = ' ';
532 		++buf;
533 	}
534 
535 	return buf;
536 }
537 
538 static noinline_for_stack
539 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
540 {
541 	struct printf_spec spec;
542 
543 	spec.type = FORMAT_TYPE_PTR;
544 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
545 	spec.flags = SPECIAL | SMALL | ZEROPAD;
546 	spec.base = 16;
547 	spec.precision = -1;
548 
549 	return number(buf, end, num, spec);
550 }
551 
552 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
553 {
554 	size_t size;
555 	if (buf >= end)	/* nowhere to put anything */
556 		return;
557 	size = end - buf;
558 	if (size <= spaces) {
559 		memset(buf, ' ', size);
560 		return;
561 	}
562 	if (len) {
563 		if (len > size - spaces)
564 			len = size - spaces;
565 		memmove(buf + spaces, buf, len);
566 	}
567 	memset(buf, ' ', spaces);
568 }
569 
570 /*
571  * Handle field width padding for a string.
572  * @buf: current buffer position
573  * @n: length of string
574  * @end: end of output buffer
575  * @spec: for field width and flags
576  * Returns: new buffer position after padding.
577  */
578 static noinline_for_stack
579 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
580 {
581 	unsigned spaces;
582 
583 	if (likely(n >= spec.field_width))
584 		return buf;
585 	/* we want to pad the sucker */
586 	spaces = spec.field_width - n;
587 	if (!(spec.flags & LEFT)) {
588 		move_right(buf - n, end, n, spaces);
589 		return buf + spaces;
590 	}
591 	while (spaces--) {
592 		if (buf < end)
593 			*buf = ' ';
594 		++buf;
595 	}
596 	return buf;
597 }
598 
599 /* Handle string from a well known address. */
600 static char *string_nocheck(char *buf, char *end, const char *s,
601 			    struct printf_spec spec)
602 {
603 	int len = 0;
604 	int lim = spec.precision;
605 
606 	while (lim--) {
607 		char c = *s++;
608 		if (!c)
609 			break;
610 		if (buf < end)
611 			*buf = c;
612 		++buf;
613 		++len;
614 	}
615 	return widen_string(buf, len, end, spec);
616 }
617 
618 static char *err_ptr(char *buf, char *end, void *ptr,
619 		     struct printf_spec spec)
620 {
621 	int err = PTR_ERR(ptr);
622 	const char *sym = errname(err);
623 
624 	if (sym)
625 		return string_nocheck(buf, end, sym, spec);
626 
627 	/*
628 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
629 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
630 	 * printing it as its decimal representation.
631 	 */
632 	spec.flags |= SIGN;
633 	spec.base = 10;
634 	return number(buf, end, err, spec);
635 }
636 
637 /* Be careful: error messages must fit into the given buffer. */
638 static char *error_string(char *buf, char *end, const char *s,
639 			  struct printf_spec spec)
640 {
641 	/*
642 	 * Hard limit to avoid a completely insane messages. It actually
643 	 * works pretty well because most error messages are in
644 	 * the many pointer format modifiers.
645 	 */
646 	if (spec.precision == -1)
647 		spec.precision = 2 * sizeof(void *);
648 
649 	return string_nocheck(buf, end, s, spec);
650 }
651 
652 /*
653  * Do not call any complex external code here. Nested printk()/vsprintf()
654  * might cause infinite loops. Failures might break printk() and would
655  * be hard to debug.
656  */
657 static const char *check_pointer_msg(const void *ptr)
658 {
659 	if (!ptr)
660 		return "(null)";
661 
662 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
663 		return "(efault)";
664 
665 	return NULL;
666 }
667 
668 static int check_pointer(char **buf, char *end, const void *ptr,
669 			 struct printf_spec spec)
670 {
671 	const char *err_msg;
672 
673 	err_msg = check_pointer_msg(ptr);
674 	if (err_msg) {
675 		*buf = error_string(*buf, end, err_msg, spec);
676 		return -EFAULT;
677 	}
678 
679 	return 0;
680 }
681 
682 static noinline_for_stack
683 char *string(char *buf, char *end, const char *s,
684 	     struct printf_spec spec)
685 {
686 	if (check_pointer(&buf, end, s, spec))
687 		return buf;
688 
689 	return string_nocheck(buf, end, s, spec);
690 }
691 
692 static char *pointer_string(char *buf, char *end,
693 			    const void *ptr,
694 			    struct printf_spec spec)
695 {
696 	spec.base = 16;
697 	spec.flags |= SMALL;
698 	if (spec.field_width == -1) {
699 		spec.field_width = 2 * sizeof(ptr);
700 		spec.flags |= ZEROPAD;
701 	}
702 
703 	return number(buf, end, (unsigned long int)ptr, spec);
704 }
705 
706 /* Make pointers available for printing early in the boot sequence. */
707 static int debug_boot_weak_hash __ro_after_init;
708 
709 static int __init debug_boot_weak_hash_enable(char *str)
710 {
711 	debug_boot_weak_hash = 1;
712 	pr_info("debug_boot_weak_hash enabled\n");
713 	return 0;
714 }
715 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
716 
717 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
718 static siphash_key_t ptr_key __read_mostly;
719 
720 static void enable_ptr_key_workfn(struct work_struct *work)
721 {
722 	get_random_bytes(&ptr_key, sizeof(ptr_key));
723 	/* Needs to run from preemptible context */
724 	static_branch_disable(&not_filled_random_ptr_key);
725 }
726 
727 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
728 
729 static void fill_random_ptr_key(struct random_ready_callback *unused)
730 {
731 	/* This may be in an interrupt handler. */
732 	queue_work(system_unbound_wq, &enable_ptr_key_work);
733 }
734 
735 static struct random_ready_callback random_ready = {
736 	.func = fill_random_ptr_key
737 };
738 
739 static int __init initialize_ptr_random(void)
740 {
741 	int key_size = sizeof(ptr_key);
742 	int ret;
743 
744 	/* Use hw RNG if available. */
745 	if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
746 		static_branch_disable(&not_filled_random_ptr_key);
747 		return 0;
748 	}
749 
750 	ret = add_random_ready_callback(&random_ready);
751 	if (!ret) {
752 		return 0;
753 	} else if (ret == -EALREADY) {
754 		/* This is in preemptible context */
755 		enable_ptr_key_workfn(&enable_ptr_key_work);
756 		return 0;
757 	}
758 
759 	return ret;
760 }
761 early_initcall(initialize_ptr_random);
762 
763 /* Maps a pointer to a 32 bit unique identifier. */
764 static char *ptr_to_id(char *buf, char *end, const void *ptr,
765 		       struct printf_spec spec)
766 {
767 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
768 	unsigned long hashval;
769 
770 	/* When debugging early boot use non-cryptographically secure hash. */
771 	if (unlikely(debug_boot_weak_hash)) {
772 		hashval = hash_long((unsigned long)ptr, 32);
773 		return pointer_string(buf, end, (const void *)hashval, spec);
774 	}
775 
776 	if (static_branch_unlikely(&not_filled_random_ptr_key)) {
777 		spec.field_width = 2 * sizeof(ptr);
778 		/* string length must be less than default_width */
779 		return error_string(buf, end, str, spec);
780 	}
781 
782 #ifdef CONFIG_64BIT
783 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
784 	/*
785 	 * Mask off the first 32 bits, this makes explicit that we have
786 	 * modified the address (and 32 bits is plenty for a unique ID).
787 	 */
788 	hashval = hashval & 0xffffffff;
789 #else
790 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
791 #endif
792 	return pointer_string(buf, end, (const void *)hashval, spec);
793 }
794 
795 int kptr_restrict __read_mostly;
796 
797 static noinline_for_stack
798 char *restricted_pointer(char *buf, char *end, const void *ptr,
799 			 struct printf_spec spec)
800 {
801 	switch (kptr_restrict) {
802 	case 0:
803 		/* Handle as %p, hash and do _not_ leak addresses. */
804 		return ptr_to_id(buf, end, ptr, spec);
805 	case 1: {
806 		const struct cred *cred;
807 
808 		/*
809 		 * kptr_restrict==1 cannot be used in IRQ context
810 		 * because its test for CAP_SYSLOG would be meaningless.
811 		 */
812 		if (in_irq() || in_serving_softirq() || in_nmi()) {
813 			if (spec.field_width == -1)
814 				spec.field_width = 2 * sizeof(ptr);
815 			return error_string(buf, end, "pK-error", spec);
816 		}
817 
818 		/*
819 		 * Only print the real pointer value if the current
820 		 * process has CAP_SYSLOG and is running with the
821 		 * same credentials it started with. This is because
822 		 * access to files is checked at open() time, but %pK
823 		 * checks permission at read() time. We don't want to
824 		 * leak pointer values if a binary opens a file using
825 		 * %pK and then elevates privileges before reading it.
826 		 */
827 		cred = current_cred();
828 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
829 		    !uid_eq(cred->euid, cred->uid) ||
830 		    !gid_eq(cred->egid, cred->gid))
831 			ptr = NULL;
832 		break;
833 	}
834 	case 2:
835 	default:
836 		/* Always print 0's for %pK */
837 		ptr = NULL;
838 		break;
839 	}
840 
841 	return pointer_string(buf, end, ptr, spec);
842 }
843 
844 static noinline_for_stack
845 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
846 		  const char *fmt)
847 {
848 	const char *array[4], *s;
849 	const struct dentry *p;
850 	int depth;
851 	int i, n;
852 
853 	switch (fmt[1]) {
854 		case '2': case '3': case '4':
855 			depth = fmt[1] - '0';
856 			break;
857 		default:
858 			depth = 1;
859 	}
860 
861 	rcu_read_lock();
862 	for (i = 0; i < depth; i++, d = p) {
863 		if (check_pointer(&buf, end, d, spec)) {
864 			rcu_read_unlock();
865 			return buf;
866 		}
867 
868 		p = READ_ONCE(d->d_parent);
869 		array[i] = READ_ONCE(d->d_name.name);
870 		if (p == d) {
871 			if (i)
872 				array[i] = "";
873 			i++;
874 			break;
875 		}
876 	}
877 	s = array[--i];
878 	for (n = 0; n != spec.precision; n++, buf++) {
879 		char c = *s++;
880 		if (!c) {
881 			if (!i)
882 				break;
883 			c = '/';
884 			s = array[--i];
885 		}
886 		if (buf < end)
887 			*buf = c;
888 	}
889 	rcu_read_unlock();
890 	return widen_string(buf, n, end, spec);
891 }
892 
893 static noinline_for_stack
894 char *file_dentry_name(char *buf, char *end, const struct file *f,
895 			struct printf_spec spec, const char *fmt)
896 {
897 	if (check_pointer(&buf, end, f, spec))
898 		return buf;
899 
900 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
901 }
902 #ifdef CONFIG_BLOCK
903 static noinline_for_stack
904 char *bdev_name(char *buf, char *end, struct block_device *bdev,
905 		struct printf_spec spec, const char *fmt)
906 {
907 	struct gendisk *hd;
908 
909 	if (check_pointer(&buf, end, bdev, spec))
910 		return buf;
911 
912 	hd = bdev->bd_disk;
913 	buf = string(buf, end, hd->disk_name, spec);
914 	if (bdev->bd_part->partno) {
915 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
916 			if (buf < end)
917 				*buf = 'p';
918 			buf++;
919 		}
920 		buf = number(buf, end, bdev->bd_part->partno, spec);
921 	}
922 	return buf;
923 }
924 #endif
925 
926 static noinline_for_stack
927 char *symbol_string(char *buf, char *end, void *ptr,
928 		    struct printf_spec spec, const char *fmt)
929 {
930 	unsigned long value;
931 #ifdef CONFIG_KALLSYMS
932 	char sym[KSYM_SYMBOL_LEN];
933 #endif
934 
935 	if (fmt[1] == 'R')
936 		ptr = __builtin_extract_return_addr(ptr);
937 	value = (unsigned long)ptr;
938 
939 #ifdef CONFIG_KALLSYMS
940 	if (*fmt == 'B')
941 		sprint_backtrace(sym, value);
942 	else if (*fmt != 's')
943 		sprint_symbol(sym, value);
944 	else
945 		sprint_symbol_no_offset(sym, value);
946 
947 	return string_nocheck(buf, end, sym, spec);
948 #else
949 	return special_hex_number(buf, end, value, sizeof(void *));
950 #endif
951 }
952 
953 static const struct printf_spec default_str_spec = {
954 	.field_width = -1,
955 	.precision = -1,
956 };
957 
958 static const struct printf_spec default_flag_spec = {
959 	.base = 16,
960 	.precision = -1,
961 	.flags = SPECIAL | SMALL,
962 };
963 
964 static const struct printf_spec default_dec_spec = {
965 	.base = 10,
966 	.precision = -1,
967 };
968 
969 static const struct printf_spec default_dec02_spec = {
970 	.base = 10,
971 	.field_width = 2,
972 	.precision = -1,
973 	.flags = ZEROPAD,
974 };
975 
976 static const struct printf_spec default_dec04_spec = {
977 	.base = 10,
978 	.field_width = 4,
979 	.precision = -1,
980 	.flags = ZEROPAD,
981 };
982 
983 static noinline_for_stack
984 char *resource_string(char *buf, char *end, struct resource *res,
985 		      struct printf_spec spec, const char *fmt)
986 {
987 #ifndef IO_RSRC_PRINTK_SIZE
988 #define IO_RSRC_PRINTK_SIZE	6
989 #endif
990 
991 #ifndef MEM_RSRC_PRINTK_SIZE
992 #define MEM_RSRC_PRINTK_SIZE	10
993 #endif
994 	static const struct printf_spec io_spec = {
995 		.base = 16,
996 		.field_width = IO_RSRC_PRINTK_SIZE,
997 		.precision = -1,
998 		.flags = SPECIAL | SMALL | ZEROPAD,
999 	};
1000 	static const struct printf_spec mem_spec = {
1001 		.base = 16,
1002 		.field_width = MEM_RSRC_PRINTK_SIZE,
1003 		.precision = -1,
1004 		.flags = SPECIAL | SMALL | ZEROPAD,
1005 	};
1006 	static const struct printf_spec bus_spec = {
1007 		.base = 16,
1008 		.field_width = 2,
1009 		.precision = -1,
1010 		.flags = SMALL | ZEROPAD,
1011 	};
1012 	static const struct printf_spec str_spec = {
1013 		.field_width = -1,
1014 		.precision = 10,
1015 		.flags = LEFT,
1016 	};
1017 
1018 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1019 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1020 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1021 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1022 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1023 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1024 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1025 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1026 
1027 	char *p = sym, *pend = sym + sizeof(sym);
1028 	int decode = (fmt[0] == 'R') ? 1 : 0;
1029 	const struct printf_spec *specp;
1030 
1031 	if (check_pointer(&buf, end, res, spec))
1032 		return buf;
1033 
1034 	*p++ = '[';
1035 	if (res->flags & IORESOURCE_IO) {
1036 		p = string_nocheck(p, pend, "io  ", str_spec);
1037 		specp = &io_spec;
1038 	} else if (res->flags & IORESOURCE_MEM) {
1039 		p = string_nocheck(p, pend, "mem ", str_spec);
1040 		specp = &mem_spec;
1041 	} else if (res->flags & IORESOURCE_IRQ) {
1042 		p = string_nocheck(p, pend, "irq ", str_spec);
1043 		specp = &default_dec_spec;
1044 	} else if (res->flags & IORESOURCE_DMA) {
1045 		p = string_nocheck(p, pend, "dma ", str_spec);
1046 		specp = &default_dec_spec;
1047 	} else if (res->flags & IORESOURCE_BUS) {
1048 		p = string_nocheck(p, pend, "bus ", str_spec);
1049 		specp = &bus_spec;
1050 	} else {
1051 		p = string_nocheck(p, pend, "??? ", str_spec);
1052 		specp = &mem_spec;
1053 		decode = 0;
1054 	}
1055 	if (decode && res->flags & IORESOURCE_UNSET) {
1056 		p = string_nocheck(p, pend, "size ", str_spec);
1057 		p = number(p, pend, resource_size(res), *specp);
1058 	} else {
1059 		p = number(p, pend, res->start, *specp);
1060 		if (res->start != res->end) {
1061 			*p++ = '-';
1062 			p = number(p, pend, res->end, *specp);
1063 		}
1064 	}
1065 	if (decode) {
1066 		if (res->flags & IORESOURCE_MEM_64)
1067 			p = string_nocheck(p, pend, " 64bit", str_spec);
1068 		if (res->flags & IORESOURCE_PREFETCH)
1069 			p = string_nocheck(p, pend, " pref", str_spec);
1070 		if (res->flags & IORESOURCE_WINDOW)
1071 			p = string_nocheck(p, pend, " window", str_spec);
1072 		if (res->flags & IORESOURCE_DISABLED)
1073 			p = string_nocheck(p, pend, " disabled", str_spec);
1074 	} else {
1075 		p = string_nocheck(p, pend, " flags ", str_spec);
1076 		p = number(p, pend, res->flags, default_flag_spec);
1077 	}
1078 	*p++ = ']';
1079 	*p = '\0';
1080 
1081 	return string_nocheck(buf, end, sym, spec);
1082 }
1083 
1084 static noinline_for_stack
1085 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1086 		 const char *fmt)
1087 {
1088 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1089 				   negative value, fallback to the default */
1090 	char separator;
1091 
1092 	if (spec.field_width == 0)
1093 		/* nothing to print */
1094 		return buf;
1095 
1096 	if (check_pointer(&buf, end, addr, spec))
1097 		return buf;
1098 
1099 	switch (fmt[1]) {
1100 	case 'C':
1101 		separator = ':';
1102 		break;
1103 	case 'D':
1104 		separator = '-';
1105 		break;
1106 	case 'N':
1107 		separator = 0;
1108 		break;
1109 	default:
1110 		separator = ' ';
1111 		break;
1112 	}
1113 
1114 	if (spec.field_width > 0)
1115 		len = min_t(int, spec.field_width, 64);
1116 
1117 	for (i = 0; i < len; ++i) {
1118 		if (buf < end)
1119 			*buf = hex_asc_hi(addr[i]);
1120 		++buf;
1121 		if (buf < end)
1122 			*buf = hex_asc_lo(addr[i]);
1123 		++buf;
1124 
1125 		if (separator && i != len - 1) {
1126 			if (buf < end)
1127 				*buf = separator;
1128 			++buf;
1129 		}
1130 	}
1131 
1132 	return buf;
1133 }
1134 
1135 static noinline_for_stack
1136 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1137 		    struct printf_spec spec, const char *fmt)
1138 {
1139 	const int CHUNKSZ = 32;
1140 	int nr_bits = max_t(int, spec.field_width, 0);
1141 	int i, chunksz;
1142 	bool first = true;
1143 
1144 	if (check_pointer(&buf, end, bitmap, spec))
1145 		return buf;
1146 
1147 	/* reused to print numbers */
1148 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1149 
1150 	chunksz = nr_bits & (CHUNKSZ - 1);
1151 	if (chunksz == 0)
1152 		chunksz = CHUNKSZ;
1153 
1154 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1155 	for (; i >= 0; i -= CHUNKSZ) {
1156 		u32 chunkmask, val;
1157 		int word, bit;
1158 
1159 		chunkmask = ((1ULL << chunksz) - 1);
1160 		word = i / BITS_PER_LONG;
1161 		bit = i % BITS_PER_LONG;
1162 		val = (bitmap[word] >> bit) & chunkmask;
1163 
1164 		if (!first) {
1165 			if (buf < end)
1166 				*buf = ',';
1167 			buf++;
1168 		}
1169 		first = false;
1170 
1171 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1172 		buf = number(buf, end, val, spec);
1173 
1174 		chunksz = CHUNKSZ;
1175 	}
1176 	return buf;
1177 }
1178 
1179 static noinline_for_stack
1180 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1181 			 struct printf_spec spec, const char *fmt)
1182 {
1183 	int nr_bits = max_t(int, spec.field_width, 0);
1184 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
1185 	int cur, rbot, rtop;
1186 	bool first = true;
1187 
1188 	if (check_pointer(&buf, end, bitmap, spec))
1189 		return buf;
1190 
1191 	rbot = cur = find_first_bit(bitmap, nr_bits);
1192 	while (cur < nr_bits) {
1193 		rtop = cur;
1194 		cur = find_next_bit(bitmap, nr_bits, cur + 1);
1195 		if (cur < nr_bits && cur <= rtop + 1)
1196 			continue;
1197 
1198 		if (!first) {
1199 			if (buf < end)
1200 				*buf = ',';
1201 			buf++;
1202 		}
1203 		first = false;
1204 
1205 		buf = number(buf, end, rbot, default_dec_spec);
1206 		if (rbot < rtop) {
1207 			if (buf < end)
1208 				*buf = '-';
1209 			buf++;
1210 
1211 			buf = number(buf, end, rtop, default_dec_spec);
1212 		}
1213 
1214 		rbot = cur;
1215 	}
1216 	return buf;
1217 }
1218 
1219 static noinline_for_stack
1220 char *mac_address_string(char *buf, char *end, u8 *addr,
1221 			 struct printf_spec spec, const char *fmt)
1222 {
1223 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1224 	char *p = mac_addr;
1225 	int i;
1226 	char separator;
1227 	bool reversed = false;
1228 
1229 	if (check_pointer(&buf, end, addr, spec))
1230 		return buf;
1231 
1232 	switch (fmt[1]) {
1233 	case 'F':
1234 		separator = '-';
1235 		break;
1236 
1237 	case 'R':
1238 		reversed = true;
1239 		/* fall through */
1240 
1241 	default:
1242 		separator = ':';
1243 		break;
1244 	}
1245 
1246 	for (i = 0; i < 6; i++) {
1247 		if (reversed)
1248 			p = hex_byte_pack(p, addr[5 - i]);
1249 		else
1250 			p = hex_byte_pack(p, addr[i]);
1251 
1252 		if (fmt[0] == 'M' && i != 5)
1253 			*p++ = separator;
1254 	}
1255 	*p = '\0';
1256 
1257 	return string_nocheck(buf, end, mac_addr, spec);
1258 }
1259 
1260 static noinline_for_stack
1261 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1262 {
1263 	int i;
1264 	bool leading_zeros = (fmt[0] == 'i');
1265 	int index;
1266 	int step;
1267 
1268 	switch (fmt[2]) {
1269 	case 'h':
1270 #ifdef __BIG_ENDIAN
1271 		index = 0;
1272 		step = 1;
1273 #else
1274 		index = 3;
1275 		step = -1;
1276 #endif
1277 		break;
1278 	case 'l':
1279 		index = 3;
1280 		step = -1;
1281 		break;
1282 	case 'n':
1283 	case 'b':
1284 	default:
1285 		index = 0;
1286 		step = 1;
1287 		break;
1288 	}
1289 	for (i = 0; i < 4; i++) {
1290 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1291 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1292 		if (leading_zeros) {
1293 			if (digits < 3)
1294 				*p++ = '0';
1295 			if (digits < 2)
1296 				*p++ = '0';
1297 		}
1298 		/* reverse the digits in the quad */
1299 		while (digits--)
1300 			*p++ = temp[digits];
1301 		if (i < 3)
1302 			*p++ = '.';
1303 		index += step;
1304 	}
1305 	*p = '\0';
1306 
1307 	return p;
1308 }
1309 
1310 static noinline_for_stack
1311 char *ip6_compressed_string(char *p, const char *addr)
1312 {
1313 	int i, j, range;
1314 	unsigned char zerolength[8];
1315 	int longest = 1;
1316 	int colonpos = -1;
1317 	u16 word;
1318 	u8 hi, lo;
1319 	bool needcolon = false;
1320 	bool useIPv4;
1321 	struct in6_addr in6;
1322 
1323 	memcpy(&in6, addr, sizeof(struct in6_addr));
1324 
1325 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1326 
1327 	memset(zerolength, 0, sizeof(zerolength));
1328 
1329 	if (useIPv4)
1330 		range = 6;
1331 	else
1332 		range = 8;
1333 
1334 	/* find position of longest 0 run */
1335 	for (i = 0; i < range; i++) {
1336 		for (j = i; j < range; j++) {
1337 			if (in6.s6_addr16[j] != 0)
1338 				break;
1339 			zerolength[i]++;
1340 		}
1341 	}
1342 	for (i = 0; i < range; i++) {
1343 		if (zerolength[i] > longest) {
1344 			longest = zerolength[i];
1345 			colonpos = i;
1346 		}
1347 	}
1348 	if (longest == 1)		/* don't compress a single 0 */
1349 		colonpos = -1;
1350 
1351 	/* emit address */
1352 	for (i = 0; i < range; i++) {
1353 		if (i == colonpos) {
1354 			if (needcolon || i == 0)
1355 				*p++ = ':';
1356 			*p++ = ':';
1357 			needcolon = false;
1358 			i += longest - 1;
1359 			continue;
1360 		}
1361 		if (needcolon) {
1362 			*p++ = ':';
1363 			needcolon = false;
1364 		}
1365 		/* hex u16 without leading 0s */
1366 		word = ntohs(in6.s6_addr16[i]);
1367 		hi = word >> 8;
1368 		lo = word & 0xff;
1369 		if (hi) {
1370 			if (hi > 0x0f)
1371 				p = hex_byte_pack(p, hi);
1372 			else
1373 				*p++ = hex_asc_lo(hi);
1374 			p = hex_byte_pack(p, lo);
1375 		}
1376 		else if (lo > 0x0f)
1377 			p = hex_byte_pack(p, lo);
1378 		else
1379 			*p++ = hex_asc_lo(lo);
1380 		needcolon = true;
1381 	}
1382 
1383 	if (useIPv4) {
1384 		if (needcolon)
1385 			*p++ = ':';
1386 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1387 	}
1388 	*p = '\0';
1389 
1390 	return p;
1391 }
1392 
1393 static noinline_for_stack
1394 char *ip6_string(char *p, const char *addr, const char *fmt)
1395 {
1396 	int i;
1397 
1398 	for (i = 0; i < 8; i++) {
1399 		p = hex_byte_pack(p, *addr++);
1400 		p = hex_byte_pack(p, *addr++);
1401 		if (fmt[0] == 'I' && i != 7)
1402 			*p++ = ':';
1403 	}
1404 	*p = '\0';
1405 
1406 	return p;
1407 }
1408 
1409 static noinline_for_stack
1410 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1411 		      struct printf_spec spec, const char *fmt)
1412 {
1413 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1414 
1415 	if (fmt[0] == 'I' && fmt[2] == 'c')
1416 		ip6_compressed_string(ip6_addr, addr);
1417 	else
1418 		ip6_string(ip6_addr, addr, fmt);
1419 
1420 	return string_nocheck(buf, end, ip6_addr, spec);
1421 }
1422 
1423 static noinline_for_stack
1424 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1425 		      struct printf_spec spec, const char *fmt)
1426 {
1427 	char ip4_addr[sizeof("255.255.255.255")];
1428 
1429 	ip4_string(ip4_addr, addr, fmt);
1430 
1431 	return string_nocheck(buf, end, ip4_addr, spec);
1432 }
1433 
1434 static noinline_for_stack
1435 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1436 			 struct printf_spec spec, const char *fmt)
1437 {
1438 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1439 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1440 		      sizeof(":12345") + sizeof("/123456789") +
1441 		      sizeof("%1234567890")];
1442 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1443 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1444 	char fmt6[2] = { fmt[0], '6' };
1445 	u8 off = 0;
1446 
1447 	fmt++;
1448 	while (isalpha(*++fmt)) {
1449 		switch (*fmt) {
1450 		case 'p':
1451 			have_p = true;
1452 			break;
1453 		case 'f':
1454 			have_f = true;
1455 			break;
1456 		case 's':
1457 			have_s = true;
1458 			break;
1459 		case 'c':
1460 			have_c = true;
1461 			break;
1462 		}
1463 	}
1464 
1465 	if (have_p || have_s || have_f) {
1466 		*p = '[';
1467 		off = 1;
1468 	}
1469 
1470 	if (fmt6[0] == 'I' && have_c)
1471 		p = ip6_compressed_string(ip6_addr + off, addr);
1472 	else
1473 		p = ip6_string(ip6_addr + off, addr, fmt6);
1474 
1475 	if (have_p || have_s || have_f)
1476 		*p++ = ']';
1477 
1478 	if (have_p) {
1479 		*p++ = ':';
1480 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1481 	}
1482 	if (have_f) {
1483 		*p++ = '/';
1484 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1485 					  IPV6_FLOWINFO_MASK), spec);
1486 	}
1487 	if (have_s) {
1488 		*p++ = '%';
1489 		p = number(p, pend, sa->sin6_scope_id, spec);
1490 	}
1491 	*p = '\0';
1492 
1493 	return string_nocheck(buf, end, ip6_addr, spec);
1494 }
1495 
1496 static noinline_for_stack
1497 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1498 			 struct printf_spec spec, const char *fmt)
1499 {
1500 	bool have_p = false;
1501 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1502 	char *pend = ip4_addr + sizeof(ip4_addr);
1503 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1504 	char fmt4[3] = { fmt[0], '4', 0 };
1505 
1506 	fmt++;
1507 	while (isalpha(*++fmt)) {
1508 		switch (*fmt) {
1509 		case 'p':
1510 			have_p = true;
1511 			break;
1512 		case 'h':
1513 		case 'l':
1514 		case 'n':
1515 		case 'b':
1516 			fmt4[2] = *fmt;
1517 			break;
1518 		}
1519 	}
1520 
1521 	p = ip4_string(ip4_addr, addr, fmt4);
1522 	if (have_p) {
1523 		*p++ = ':';
1524 		p = number(p, pend, ntohs(sa->sin_port), spec);
1525 	}
1526 	*p = '\0';
1527 
1528 	return string_nocheck(buf, end, ip4_addr, spec);
1529 }
1530 
1531 static noinline_for_stack
1532 char *ip_addr_string(char *buf, char *end, const void *ptr,
1533 		     struct printf_spec spec, const char *fmt)
1534 {
1535 	char *err_fmt_msg;
1536 
1537 	if (check_pointer(&buf, end, ptr, spec))
1538 		return buf;
1539 
1540 	switch (fmt[1]) {
1541 	case '6':
1542 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1543 	case '4':
1544 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1545 	case 'S': {
1546 		const union {
1547 			struct sockaddr		raw;
1548 			struct sockaddr_in	v4;
1549 			struct sockaddr_in6	v6;
1550 		} *sa = ptr;
1551 
1552 		switch (sa->raw.sa_family) {
1553 		case AF_INET:
1554 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1555 		case AF_INET6:
1556 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1557 		default:
1558 			return error_string(buf, end, "(einval)", spec);
1559 		}}
1560 	}
1561 
1562 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1563 	return error_string(buf, end, err_fmt_msg, spec);
1564 }
1565 
1566 static noinline_for_stack
1567 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1568 		     const char *fmt)
1569 {
1570 	bool found = true;
1571 	int count = 1;
1572 	unsigned int flags = 0;
1573 	int len;
1574 
1575 	if (spec.field_width == 0)
1576 		return buf;				/* nothing to print */
1577 
1578 	if (check_pointer(&buf, end, addr, spec))
1579 		return buf;
1580 
1581 	do {
1582 		switch (fmt[count++]) {
1583 		case 'a':
1584 			flags |= ESCAPE_ANY;
1585 			break;
1586 		case 'c':
1587 			flags |= ESCAPE_SPECIAL;
1588 			break;
1589 		case 'h':
1590 			flags |= ESCAPE_HEX;
1591 			break;
1592 		case 'n':
1593 			flags |= ESCAPE_NULL;
1594 			break;
1595 		case 'o':
1596 			flags |= ESCAPE_OCTAL;
1597 			break;
1598 		case 'p':
1599 			flags |= ESCAPE_NP;
1600 			break;
1601 		case 's':
1602 			flags |= ESCAPE_SPACE;
1603 			break;
1604 		default:
1605 			found = false;
1606 			break;
1607 		}
1608 	} while (found);
1609 
1610 	if (!flags)
1611 		flags = ESCAPE_ANY_NP;
1612 
1613 	len = spec.field_width < 0 ? 1 : spec.field_width;
1614 
1615 	/*
1616 	 * string_escape_mem() writes as many characters as it can to
1617 	 * the given buffer, and returns the total size of the output
1618 	 * had the buffer been big enough.
1619 	 */
1620 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1621 
1622 	return buf;
1623 }
1624 
1625 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1626 		       struct printf_spec spec, const char *fmt)
1627 {
1628 	va_list va;
1629 
1630 	if (check_pointer(&buf, end, va_fmt, spec))
1631 		return buf;
1632 
1633 	va_copy(va, *va_fmt->va);
1634 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1635 	va_end(va);
1636 
1637 	return buf;
1638 }
1639 
1640 static noinline_for_stack
1641 char *uuid_string(char *buf, char *end, const u8 *addr,
1642 		  struct printf_spec spec, const char *fmt)
1643 {
1644 	char uuid[UUID_STRING_LEN + 1];
1645 	char *p = uuid;
1646 	int i;
1647 	const u8 *index = uuid_index;
1648 	bool uc = false;
1649 
1650 	if (check_pointer(&buf, end, addr, spec))
1651 		return buf;
1652 
1653 	switch (*(++fmt)) {
1654 	case 'L':
1655 		uc = true;		/* fall-through */
1656 	case 'l':
1657 		index = guid_index;
1658 		break;
1659 	case 'B':
1660 		uc = true;
1661 		break;
1662 	}
1663 
1664 	for (i = 0; i < 16; i++) {
1665 		if (uc)
1666 			p = hex_byte_pack_upper(p, addr[index[i]]);
1667 		else
1668 			p = hex_byte_pack(p, addr[index[i]]);
1669 		switch (i) {
1670 		case 3:
1671 		case 5:
1672 		case 7:
1673 		case 9:
1674 			*p++ = '-';
1675 			break;
1676 		}
1677 	}
1678 
1679 	*p = 0;
1680 
1681 	return string_nocheck(buf, end, uuid, spec);
1682 }
1683 
1684 static noinline_for_stack
1685 char *netdev_bits(char *buf, char *end, const void *addr,
1686 		  struct printf_spec spec,  const char *fmt)
1687 {
1688 	unsigned long long num;
1689 	int size;
1690 
1691 	if (check_pointer(&buf, end, addr, spec))
1692 		return buf;
1693 
1694 	switch (fmt[1]) {
1695 	case 'F':
1696 		num = *(const netdev_features_t *)addr;
1697 		size = sizeof(netdev_features_t);
1698 		break;
1699 	default:
1700 		return error_string(buf, end, "(%pN?)", spec);
1701 	}
1702 
1703 	return special_hex_number(buf, end, num, size);
1704 }
1705 
1706 static noinline_for_stack
1707 char *address_val(char *buf, char *end, const void *addr,
1708 		  struct printf_spec spec, const char *fmt)
1709 {
1710 	unsigned long long num;
1711 	int size;
1712 
1713 	if (check_pointer(&buf, end, addr, spec))
1714 		return buf;
1715 
1716 	switch (fmt[1]) {
1717 	case 'd':
1718 		num = *(const dma_addr_t *)addr;
1719 		size = sizeof(dma_addr_t);
1720 		break;
1721 	case 'p':
1722 	default:
1723 		num = *(const phys_addr_t *)addr;
1724 		size = sizeof(phys_addr_t);
1725 		break;
1726 	}
1727 
1728 	return special_hex_number(buf, end, num, size);
1729 }
1730 
1731 static noinline_for_stack
1732 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1733 {
1734 	int year = tm->tm_year + (r ? 0 : 1900);
1735 	int mon = tm->tm_mon + (r ? 0 : 1);
1736 
1737 	buf = number(buf, end, year, default_dec04_spec);
1738 	if (buf < end)
1739 		*buf = '-';
1740 	buf++;
1741 
1742 	buf = number(buf, end, mon, default_dec02_spec);
1743 	if (buf < end)
1744 		*buf = '-';
1745 	buf++;
1746 
1747 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1748 }
1749 
1750 static noinline_for_stack
1751 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1752 {
1753 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1754 	if (buf < end)
1755 		*buf = ':';
1756 	buf++;
1757 
1758 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1759 	if (buf < end)
1760 		*buf = ':';
1761 	buf++;
1762 
1763 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1764 }
1765 
1766 static noinline_for_stack
1767 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1768 	      struct printf_spec spec, const char *fmt)
1769 {
1770 	bool have_t = true, have_d = true;
1771 	bool raw = false;
1772 	int count = 2;
1773 
1774 	if (check_pointer(&buf, end, tm, spec))
1775 		return buf;
1776 
1777 	switch (fmt[count]) {
1778 	case 'd':
1779 		have_t = false;
1780 		count++;
1781 		break;
1782 	case 't':
1783 		have_d = false;
1784 		count++;
1785 		break;
1786 	}
1787 
1788 	raw = fmt[count] == 'r';
1789 
1790 	if (have_d)
1791 		buf = date_str(buf, end, tm, raw);
1792 	if (have_d && have_t) {
1793 		/* Respect ISO 8601 */
1794 		if (buf < end)
1795 			*buf = 'T';
1796 		buf++;
1797 	}
1798 	if (have_t)
1799 		buf = time_str(buf, end, tm, raw);
1800 
1801 	return buf;
1802 }
1803 
1804 static noinline_for_stack
1805 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1806 		    const char *fmt)
1807 {
1808 	switch (fmt[1]) {
1809 	case 'R':
1810 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1811 	default:
1812 		return error_string(buf, end, "(%ptR?)", spec);
1813 	}
1814 }
1815 
1816 static noinline_for_stack
1817 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1818 	    const char *fmt)
1819 {
1820 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1821 		return error_string(buf, end, "(%pC?)", spec);
1822 
1823 	if (check_pointer(&buf, end, clk, spec))
1824 		return buf;
1825 
1826 	switch (fmt[1]) {
1827 	case 'n':
1828 	default:
1829 #ifdef CONFIG_COMMON_CLK
1830 		return string(buf, end, __clk_get_name(clk), spec);
1831 #else
1832 		return ptr_to_id(buf, end, clk, spec);
1833 #endif
1834 	}
1835 }
1836 
1837 static
1838 char *format_flags(char *buf, char *end, unsigned long flags,
1839 					const struct trace_print_flags *names)
1840 {
1841 	unsigned long mask;
1842 
1843 	for ( ; flags && names->name; names++) {
1844 		mask = names->mask;
1845 		if ((flags & mask) != mask)
1846 			continue;
1847 
1848 		buf = string(buf, end, names->name, default_str_spec);
1849 
1850 		flags &= ~mask;
1851 		if (flags) {
1852 			if (buf < end)
1853 				*buf = '|';
1854 			buf++;
1855 		}
1856 	}
1857 
1858 	if (flags)
1859 		buf = number(buf, end, flags, default_flag_spec);
1860 
1861 	return buf;
1862 }
1863 
1864 static noinline_for_stack
1865 char *flags_string(char *buf, char *end, void *flags_ptr,
1866 		   struct printf_spec spec, const char *fmt)
1867 {
1868 	unsigned long flags;
1869 	const struct trace_print_flags *names;
1870 
1871 	if (check_pointer(&buf, end, flags_ptr, spec))
1872 		return buf;
1873 
1874 	switch (fmt[1]) {
1875 	case 'p':
1876 		flags = *(unsigned long *)flags_ptr;
1877 		/* Remove zone id */
1878 		flags &= (1UL << NR_PAGEFLAGS) - 1;
1879 		names = pageflag_names;
1880 		break;
1881 	case 'v':
1882 		flags = *(unsigned long *)flags_ptr;
1883 		names = vmaflag_names;
1884 		break;
1885 	case 'g':
1886 		flags = *(gfp_t *)flags_ptr;
1887 		names = gfpflag_names;
1888 		break;
1889 	default:
1890 		return error_string(buf, end, "(%pG?)", spec);
1891 	}
1892 
1893 	return format_flags(buf, end, flags, names);
1894 }
1895 
1896 static noinline_for_stack
1897 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
1898 			      char *end)
1899 {
1900 	int depth;
1901 
1902 	/* Loop starting from the root node to the current node. */
1903 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
1904 		struct fwnode_handle *__fwnode =
1905 			fwnode_get_nth_parent(fwnode, depth);
1906 
1907 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
1908 			     default_str_spec);
1909 		buf = string(buf, end, fwnode_get_name(__fwnode),
1910 			     default_str_spec);
1911 
1912 		fwnode_handle_put(__fwnode);
1913 	}
1914 
1915 	return buf;
1916 }
1917 
1918 static noinline_for_stack
1919 char *device_node_string(char *buf, char *end, struct device_node *dn,
1920 			 struct printf_spec spec, const char *fmt)
1921 {
1922 	char tbuf[sizeof("xxxx") + 1];
1923 	const char *p;
1924 	int ret;
1925 	char *buf_start = buf;
1926 	struct property *prop;
1927 	bool has_mult, pass;
1928 	static const struct printf_spec num_spec = {
1929 		.flags = SMALL,
1930 		.field_width = -1,
1931 		.precision = -1,
1932 		.base = 10,
1933 	};
1934 
1935 	struct printf_spec str_spec = spec;
1936 	str_spec.field_width = -1;
1937 
1938 	if (fmt[0] != 'F')
1939 		return error_string(buf, end, "(%pO?)", spec);
1940 
1941 	if (!IS_ENABLED(CONFIG_OF))
1942 		return error_string(buf, end, "(%pOF?)", spec);
1943 
1944 	if (check_pointer(&buf, end, dn, spec))
1945 		return buf;
1946 
1947 	/* simple case without anything any more format specifiers */
1948 	fmt++;
1949 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1950 		fmt = "f";
1951 
1952 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1953 		int precision;
1954 		if (pass) {
1955 			if (buf < end)
1956 				*buf = ':';
1957 			buf++;
1958 		}
1959 
1960 		switch (*fmt) {
1961 		case 'f':	/* full_name */
1962 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
1963 						      end);
1964 			break;
1965 		case 'n':	/* name */
1966 			p = fwnode_get_name(of_fwnode_handle(dn));
1967 			precision = str_spec.precision;
1968 			str_spec.precision = strchrnul(p, '@') - p;
1969 			buf = string(buf, end, p, str_spec);
1970 			str_spec.precision = precision;
1971 			break;
1972 		case 'p':	/* phandle */
1973 			buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1974 			break;
1975 		case 'P':	/* path-spec */
1976 			p = fwnode_get_name(of_fwnode_handle(dn));
1977 			if (!p[1])
1978 				p = "/";
1979 			buf = string(buf, end, p, str_spec);
1980 			break;
1981 		case 'F':	/* flags */
1982 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1983 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1984 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1985 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1986 			tbuf[4] = 0;
1987 			buf = string_nocheck(buf, end, tbuf, str_spec);
1988 			break;
1989 		case 'c':	/* major compatible string */
1990 			ret = of_property_read_string(dn, "compatible", &p);
1991 			if (!ret)
1992 				buf = string(buf, end, p, str_spec);
1993 			break;
1994 		case 'C':	/* full compatible string */
1995 			has_mult = false;
1996 			of_property_for_each_string(dn, "compatible", prop, p) {
1997 				if (has_mult)
1998 					buf = string_nocheck(buf, end, ",", str_spec);
1999 				buf = string_nocheck(buf, end, "\"", str_spec);
2000 				buf = string(buf, end, p, str_spec);
2001 				buf = string_nocheck(buf, end, "\"", str_spec);
2002 
2003 				has_mult = true;
2004 			}
2005 			break;
2006 		default:
2007 			break;
2008 		}
2009 	}
2010 
2011 	return widen_string(buf, buf - buf_start, end, spec);
2012 }
2013 
2014 static noinline_for_stack
2015 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2016 		    struct printf_spec spec, const char *fmt)
2017 {
2018 	struct printf_spec str_spec = spec;
2019 	char *buf_start = buf;
2020 
2021 	str_spec.field_width = -1;
2022 
2023 	if (*fmt != 'w')
2024 		return error_string(buf, end, "(%pf?)", spec);
2025 
2026 	if (check_pointer(&buf, end, fwnode, spec))
2027 		return buf;
2028 
2029 	fmt++;
2030 
2031 	switch (*fmt) {
2032 	case 'P':	/* name */
2033 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2034 		break;
2035 	case 'f':	/* full_name */
2036 	default:
2037 		buf = fwnode_full_name_string(fwnode, buf, end);
2038 		break;
2039 	}
2040 
2041 	return widen_string(buf, buf - buf_start, end, spec);
2042 }
2043 
2044 /*
2045  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2046  * by an extra set of alphanumeric characters that are extended format
2047  * specifiers.
2048  *
2049  * Please update scripts/checkpatch.pl when adding/removing conversion
2050  * characters.  (Search for "check for vsprintf extension").
2051  *
2052  * Right now we handle:
2053  *
2054  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2055  * - 's' For symbolic direct pointers (or function descriptors) without offset
2056  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2057  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2058  *	    %ps and %pS. Be careful when re-using these specifiers.
2059  * - 'B' For backtraced symbolic direct pointers with offset
2060  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2061  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2062  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2063  *       width which must be explicitly specified either as part of the
2064  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2065  *       range-list format instead of hex format
2066  * - 'M' For a 6-byte MAC address, it prints the address in the
2067  *       usual colon-separated hex notation
2068  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2069  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2070  *       with a dash-separated hex notation
2071  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2072  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2073  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2074  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2075  *       [S][pfs]
2076  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2077  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2078  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2079  *       IPv6 omits the colons (01020304...0f)
2080  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2081  *       [S][pfs]
2082  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2083  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2084  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2085  * - 'I[6S]c' for IPv6 addresses printed as specified by
2086  *       http://tools.ietf.org/html/rfc5952
2087  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2088  *                of the following flags (see string_escape_mem() for the
2089  *                details):
2090  *                  a - ESCAPE_ANY
2091  *                  c - ESCAPE_SPECIAL
2092  *                  h - ESCAPE_HEX
2093  *                  n - ESCAPE_NULL
2094  *                  o - ESCAPE_OCTAL
2095  *                  p - ESCAPE_NP
2096  *                  s - ESCAPE_SPACE
2097  *                By default ESCAPE_ANY_NP is used.
2098  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2099  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2100  *       Options for %pU are:
2101  *         b big endian lower case hex (default)
2102  *         B big endian UPPER case hex
2103  *         l little endian lower case hex
2104  *         L little endian UPPER case hex
2105  *           big endian output byte order is:
2106  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2107  *           little endian output byte order is:
2108  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2109  * - 'V' For a struct va_format which contains a format string * and va_list *,
2110  *       call vsnprintf(->format, *->va_list).
2111  *       Implements a "recursive vsnprintf".
2112  *       Do not use this feature without some mechanism to verify the
2113  *       correctness of the format string and va_list arguments.
2114  * - 'K' For a kernel pointer that should be hidden from unprivileged users
2115  * - 'NF' For a netdev_features_t
2116  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2117  *            a certain separator (' ' by default):
2118  *              C colon
2119  *              D dash
2120  *              N no separator
2121  *            The maximum supported length is 64 bytes of the input. Consider
2122  *            to use print_hex_dump() for the larger input.
2123  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2124  *           (default assumed to be phys_addr_t, passed by reference)
2125  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2126  * - 'D[234]' Same as 'd' but for a struct file
2127  * - 'g' For block_device name (gendisk + partition number)
2128  * - 't[R][dt][r]' For time and date as represented:
2129  *      R    struct rtc_time
2130  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2131  *       (legacy clock framework) of the clock
2132  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2133  *        (legacy clock framework) of the clock
2134  * - 'G' For flags to be printed as a collection of symbolic strings that would
2135  *       construct the specific value. Supported flags given by option:
2136  *       p page flags (see struct page) given as pointer to unsigned long
2137  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2138  *       v vma flags (VM_*) given as pointer to unsigned long
2139  * - 'OF[fnpPcCF]'  For a device tree object
2140  *                  Without any optional arguments prints the full_name
2141  *                  f device node full_name
2142  *                  n device node name
2143  *                  p device node phandle
2144  *                  P device node path spec (name + @unit)
2145  *                  F device node flags
2146  *                  c major compatible string
2147  *                  C full compatible string
2148  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2149  *		Without an option prints the full name of the node
2150  *		f full name
2151  *		P node name, including a possible unit address
2152  * - 'x' For printing the address. Equivalent to "%lx".
2153  *
2154  * ** When making changes please also update:
2155  *	Documentation/core-api/printk-formats.rst
2156  *
2157  * Note: The default behaviour (unadorned %p) is to hash the address,
2158  * rendering it useful as a unique identifier.
2159  */
2160 static noinline_for_stack
2161 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2162 	      struct printf_spec spec)
2163 {
2164 	switch (*fmt) {
2165 	case 'S':
2166 	case 's':
2167 		ptr = dereference_symbol_descriptor(ptr);
2168 		/* Fallthrough */
2169 	case 'B':
2170 		return symbol_string(buf, end, ptr, spec, fmt);
2171 	case 'R':
2172 	case 'r':
2173 		return resource_string(buf, end, ptr, spec, fmt);
2174 	case 'h':
2175 		return hex_string(buf, end, ptr, spec, fmt);
2176 	case 'b':
2177 		switch (fmt[1]) {
2178 		case 'l':
2179 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2180 		default:
2181 			return bitmap_string(buf, end, ptr, spec, fmt);
2182 		}
2183 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2184 	case 'm':			/* Contiguous: 000102030405 */
2185 					/* [mM]F (FDDI) */
2186 					/* [mM]R (Reverse order; Bluetooth) */
2187 		return mac_address_string(buf, end, ptr, spec, fmt);
2188 	case 'I':			/* Formatted IP supported
2189 					 * 4:	1.2.3.4
2190 					 * 6:	0001:0203:...:0708
2191 					 * 6c:	1::708 or 1::1.2.3.4
2192 					 */
2193 	case 'i':			/* Contiguous:
2194 					 * 4:	001.002.003.004
2195 					 * 6:   000102...0f
2196 					 */
2197 		return ip_addr_string(buf, end, ptr, spec, fmt);
2198 	case 'E':
2199 		return escaped_string(buf, end, ptr, spec, fmt);
2200 	case 'U':
2201 		return uuid_string(buf, end, ptr, spec, fmt);
2202 	case 'V':
2203 		return va_format(buf, end, ptr, spec, fmt);
2204 	case 'K':
2205 		return restricted_pointer(buf, end, ptr, spec);
2206 	case 'N':
2207 		return netdev_bits(buf, end, ptr, spec, fmt);
2208 	case 'a':
2209 		return address_val(buf, end, ptr, spec, fmt);
2210 	case 'd':
2211 		return dentry_name(buf, end, ptr, spec, fmt);
2212 	case 't':
2213 		return time_and_date(buf, end, ptr, spec, fmt);
2214 	case 'C':
2215 		return clock(buf, end, ptr, spec, fmt);
2216 	case 'D':
2217 		return file_dentry_name(buf, end, ptr, spec, fmt);
2218 #ifdef CONFIG_BLOCK
2219 	case 'g':
2220 		return bdev_name(buf, end, ptr, spec, fmt);
2221 #endif
2222 
2223 	case 'G':
2224 		return flags_string(buf, end, ptr, spec, fmt);
2225 	case 'O':
2226 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2227 	case 'f':
2228 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2229 	case 'x':
2230 		return pointer_string(buf, end, ptr, spec);
2231 	case 'e':
2232 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2233 		if (!IS_ERR(ptr))
2234 			break;
2235 		return err_ptr(buf, end, ptr, spec);
2236 	}
2237 
2238 	/* default is to _not_ leak addresses, hash before printing */
2239 	return ptr_to_id(buf, end, ptr, spec);
2240 }
2241 
2242 /*
2243  * Helper function to decode printf style format.
2244  * Each call decode a token from the format and return the
2245  * number of characters read (or likely the delta where it wants
2246  * to go on the next call).
2247  * The decoded token is returned through the parameters
2248  *
2249  * 'h', 'l', or 'L' for integer fields
2250  * 'z' support added 23/7/1999 S.H.
2251  * 'z' changed to 'Z' --davidm 1/25/99
2252  * 'Z' changed to 'z' --adobriyan 2017-01-25
2253  * 't' added for ptrdiff_t
2254  *
2255  * @fmt: the format string
2256  * @type of the token returned
2257  * @flags: various flags such as +, -, # tokens..
2258  * @field_width: overwritten width
2259  * @base: base of the number (octal, hex, ...)
2260  * @precision: precision of a number
2261  * @qualifier: qualifier of a number (long, size_t, ...)
2262  */
2263 static noinline_for_stack
2264 int format_decode(const char *fmt, struct printf_spec *spec)
2265 {
2266 	const char *start = fmt;
2267 	char qualifier;
2268 
2269 	/* we finished early by reading the field width */
2270 	if (spec->type == FORMAT_TYPE_WIDTH) {
2271 		if (spec->field_width < 0) {
2272 			spec->field_width = -spec->field_width;
2273 			spec->flags |= LEFT;
2274 		}
2275 		spec->type = FORMAT_TYPE_NONE;
2276 		goto precision;
2277 	}
2278 
2279 	/* we finished early by reading the precision */
2280 	if (spec->type == FORMAT_TYPE_PRECISION) {
2281 		if (spec->precision < 0)
2282 			spec->precision = 0;
2283 
2284 		spec->type = FORMAT_TYPE_NONE;
2285 		goto qualifier;
2286 	}
2287 
2288 	/* By default */
2289 	spec->type = FORMAT_TYPE_NONE;
2290 
2291 	for (; *fmt ; ++fmt) {
2292 		if (*fmt == '%')
2293 			break;
2294 	}
2295 
2296 	/* Return the current non-format string */
2297 	if (fmt != start || !*fmt)
2298 		return fmt - start;
2299 
2300 	/* Process flags */
2301 	spec->flags = 0;
2302 
2303 	while (1) { /* this also skips first '%' */
2304 		bool found = true;
2305 
2306 		++fmt;
2307 
2308 		switch (*fmt) {
2309 		case '-': spec->flags |= LEFT;    break;
2310 		case '+': spec->flags |= PLUS;    break;
2311 		case ' ': spec->flags |= SPACE;   break;
2312 		case '#': spec->flags |= SPECIAL; break;
2313 		case '0': spec->flags |= ZEROPAD; break;
2314 		default:  found = false;
2315 		}
2316 
2317 		if (!found)
2318 			break;
2319 	}
2320 
2321 	/* get field width */
2322 	spec->field_width = -1;
2323 
2324 	if (isdigit(*fmt))
2325 		spec->field_width = skip_atoi(&fmt);
2326 	else if (*fmt == '*') {
2327 		/* it's the next argument */
2328 		spec->type = FORMAT_TYPE_WIDTH;
2329 		return ++fmt - start;
2330 	}
2331 
2332 precision:
2333 	/* get the precision */
2334 	spec->precision = -1;
2335 	if (*fmt == '.') {
2336 		++fmt;
2337 		if (isdigit(*fmt)) {
2338 			spec->precision = skip_atoi(&fmt);
2339 			if (spec->precision < 0)
2340 				spec->precision = 0;
2341 		} else if (*fmt == '*') {
2342 			/* it's the next argument */
2343 			spec->type = FORMAT_TYPE_PRECISION;
2344 			return ++fmt - start;
2345 		}
2346 	}
2347 
2348 qualifier:
2349 	/* get the conversion qualifier */
2350 	qualifier = 0;
2351 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2352 	    *fmt == 'z' || *fmt == 't') {
2353 		qualifier = *fmt++;
2354 		if (unlikely(qualifier == *fmt)) {
2355 			if (qualifier == 'l') {
2356 				qualifier = 'L';
2357 				++fmt;
2358 			} else if (qualifier == 'h') {
2359 				qualifier = 'H';
2360 				++fmt;
2361 			}
2362 		}
2363 	}
2364 
2365 	/* default base */
2366 	spec->base = 10;
2367 	switch (*fmt) {
2368 	case 'c':
2369 		spec->type = FORMAT_TYPE_CHAR;
2370 		return ++fmt - start;
2371 
2372 	case 's':
2373 		spec->type = FORMAT_TYPE_STR;
2374 		return ++fmt - start;
2375 
2376 	case 'p':
2377 		spec->type = FORMAT_TYPE_PTR;
2378 		return ++fmt - start;
2379 
2380 	case '%':
2381 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2382 		return ++fmt - start;
2383 
2384 	/* integer number formats - set up the flags and "break" */
2385 	case 'o':
2386 		spec->base = 8;
2387 		break;
2388 
2389 	case 'x':
2390 		spec->flags |= SMALL;
2391 		/* fall through */
2392 
2393 	case 'X':
2394 		spec->base = 16;
2395 		break;
2396 
2397 	case 'd':
2398 	case 'i':
2399 		spec->flags |= SIGN;
2400 	case 'u':
2401 		break;
2402 
2403 	case 'n':
2404 		/*
2405 		 * Since %n poses a greater security risk than
2406 		 * utility, treat it as any other invalid or
2407 		 * unsupported format specifier.
2408 		 */
2409 		/* Fall-through */
2410 
2411 	default:
2412 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2413 		spec->type = FORMAT_TYPE_INVALID;
2414 		return fmt - start;
2415 	}
2416 
2417 	if (qualifier == 'L')
2418 		spec->type = FORMAT_TYPE_LONG_LONG;
2419 	else if (qualifier == 'l') {
2420 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2421 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2422 	} else if (qualifier == 'z') {
2423 		spec->type = FORMAT_TYPE_SIZE_T;
2424 	} else if (qualifier == 't') {
2425 		spec->type = FORMAT_TYPE_PTRDIFF;
2426 	} else if (qualifier == 'H') {
2427 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2428 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2429 	} else if (qualifier == 'h') {
2430 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2431 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2432 	} else {
2433 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2434 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2435 	}
2436 
2437 	return ++fmt - start;
2438 }
2439 
2440 static void
2441 set_field_width(struct printf_spec *spec, int width)
2442 {
2443 	spec->field_width = width;
2444 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2445 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2446 	}
2447 }
2448 
2449 static void
2450 set_precision(struct printf_spec *spec, int prec)
2451 {
2452 	spec->precision = prec;
2453 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2454 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2455 	}
2456 }
2457 
2458 /**
2459  * vsnprintf - Format a string and place it in a buffer
2460  * @buf: The buffer to place the result into
2461  * @size: The size of the buffer, including the trailing null space
2462  * @fmt: The format string to use
2463  * @args: Arguments for the format string
2464  *
2465  * This function generally follows C99 vsnprintf, but has some
2466  * extensions and a few limitations:
2467  *
2468  *  - ``%n`` is unsupported
2469  *  - ``%p*`` is handled by pointer()
2470  *
2471  * See pointer() or Documentation/core-api/printk-formats.rst for more
2472  * extensive description.
2473  *
2474  * **Please update the documentation in both places when making changes**
2475  *
2476  * The return value is the number of characters which would
2477  * be generated for the given input, excluding the trailing
2478  * '\0', as per ISO C99. If you want to have the exact
2479  * number of characters written into @buf as return value
2480  * (not including the trailing '\0'), use vscnprintf(). If the
2481  * return is greater than or equal to @size, the resulting
2482  * string is truncated.
2483  *
2484  * If you're not already dealing with a va_list consider using snprintf().
2485  */
2486 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2487 {
2488 	unsigned long long num;
2489 	char *str, *end;
2490 	struct printf_spec spec = {0};
2491 
2492 	/* Reject out-of-range values early.  Large positive sizes are
2493 	   used for unknown buffer sizes. */
2494 	if (WARN_ON_ONCE(size > INT_MAX))
2495 		return 0;
2496 
2497 	str = buf;
2498 	end = buf + size;
2499 
2500 	/* Make sure end is always >= buf */
2501 	if (end < buf) {
2502 		end = ((void *)-1);
2503 		size = end - buf;
2504 	}
2505 
2506 	while (*fmt) {
2507 		const char *old_fmt = fmt;
2508 		int read = format_decode(fmt, &spec);
2509 
2510 		fmt += read;
2511 
2512 		switch (spec.type) {
2513 		case FORMAT_TYPE_NONE: {
2514 			int copy = read;
2515 			if (str < end) {
2516 				if (copy > end - str)
2517 					copy = end - str;
2518 				memcpy(str, old_fmt, copy);
2519 			}
2520 			str += read;
2521 			break;
2522 		}
2523 
2524 		case FORMAT_TYPE_WIDTH:
2525 			set_field_width(&spec, va_arg(args, int));
2526 			break;
2527 
2528 		case FORMAT_TYPE_PRECISION:
2529 			set_precision(&spec, va_arg(args, int));
2530 			break;
2531 
2532 		case FORMAT_TYPE_CHAR: {
2533 			char c;
2534 
2535 			if (!(spec.flags & LEFT)) {
2536 				while (--spec.field_width > 0) {
2537 					if (str < end)
2538 						*str = ' ';
2539 					++str;
2540 
2541 				}
2542 			}
2543 			c = (unsigned char) va_arg(args, int);
2544 			if (str < end)
2545 				*str = c;
2546 			++str;
2547 			while (--spec.field_width > 0) {
2548 				if (str < end)
2549 					*str = ' ';
2550 				++str;
2551 			}
2552 			break;
2553 		}
2554 
2555 		case FORMAT_TYPE_STR:
2556 			str = string(str, end, va_arg(args, char *), spec);
2557 			break;
2558 
2559 		case FORMAT_TYPE_PTR:
2560 			str = pointer(fmt, str, end, va_arg(args, void *),
2561 				      spec);
2562 			while (isalnum(*fmt))
2563 				fmt++;
2564 			break;
2565 
2566 		case FORMAT_TYPE_PERCENT_CHAR:
2567 			if (str < end)
2568 				*str = '%';
2569 			++str;
2570 			break;
2571 
2572 		case FORMAT_TYPE_INVALID:
2573 			/*
2574 			 * Presumably the arguments passed gcc's type
2575 			 * checking, but there is no safe or sane way
2576 			 * for us to continue parsing the format and
2577 			 * fetching from the va_list; the remaining
2578 			 * specifiers and arguments would be out of
2579 			 * sync.
2580 			 */
2581 			goto out;
2582 
2583 		default:
2584 			switch (spec.type) {
2585 			case FORMAT_TYPE_LONG_LONG:
2586 				num = va_arg(args, long long);
2587 				break;
2588 			case FORMAT_TYPE_ULONG:
2589 				num = va_arg(args, unsigned long);
2590 				break;
2591 			case FORMAT_TYPE_LONG:
2592 				num = va_arg(args, long);
2593 				break;
2594 			case FORMAT_TYPE_SIZE_T:
2595 				if (spec.flags & SIGN)
2596 					num = va_arg(args, ssize_t);
2597 				else
2598 					num = va_arg(args, size_t);
2599 				break;
2600 			case FORMAT_TYPE_PTRDIFF:
2601 				num = va_arg(args, ptrdiff_t);
2602 				break;
2603 			case FORMAT_TYPE_UBYTE:
2604 				num = (unsigned char) va_arg(args, int);
2605 				break;
2606 			case FORMAT_TYPE_BYTE:
2607 				num = (signed char) va_arg(args, int);
2608 				break;
2609 			case FORMAT_TYPE_USHORT:
2610 				num = (unsigned short) va_arg(args, int);
2611 				break;
2612 			case FORMAT_TYPE_SHORT:
2613 				num = (short) va_arg(args, int);
2614 				break;
2615 			case FORMAT_TYPE_INT:
2616 				num = (int) va_arg(args, int);
2617 				break;
2618 			default:
2619 				num = va_arg(args, unsigned int);
2620 			}
2621 
2622 			str = number(str, end, num, spec);
2623 		}
2624 	}
2625 
2626 out:
2627 	if (size > 0) {
2628 		if (str < end)
2629 			*str = '\0';
2630 		else
2631 			end[-1] = '\0';
2632 	}
2633 
2634 	/* the trailing null byte doesn't count towards the total */
2635 	return str-buf;
2636 
2637 }
2638 EXPORT_SYMBOL(vsnprintf);
2639 
2640 /**
2641  * vscnprintf - Format a string and place it in a buffer
2642  * @buf: The buffer to place the result into
2643  * @size: The size of the buffer, including the trailing null space
2644  * @fmt: The format string to use
2645  * @args: Arguments for the format string
2646  *
2647  * The return value is the number of characters which have been written into
2648  * the @buf not including the trailing '\0'. If @size is == 0 the function
2649  * returns 0.
2650  *
2651  * If you're not already dealing with a va_list consider using scnprintf().
2652  *
2653  * See the vsnprintf() documentation for format string extensions over C99.
2654  */
2655 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2656 {
2657 	int i;
2658 
2659 	i = vsnprintf(buf, size, fmt, args);
2660 
2661 	if (likely(i < size))
2662 		return i;
2663 	if (size != 0)
2664 		return size - 1;
2665 	return 0;
2666 }
2667 EXPORT_SYMBOL(vscnprintf);
2668 
2669 /**
2670  * snprintf - Format a string and place it in a buffer
2671  * @buf: The buffer to place the result into
2672  * @size: The size of the buffer, including the trailing null space
2673  * @fmt: The format string to use
2674  * @...: Arguments for the format string
2675  *
2676  * The return value is the number of characters which would be
2677  * generated for the given input, excluding the trailing null,
2678  * as per ISO C99.  If the return is greater than or equal to
2679  * @size, the resulting string is truncated.
2680  *
2681  * See the vsnprintf() documentation for format string extensions over C99.
2682  */
2683 int snprintf(char *buf, size_t size, const char *fmt, ...)
2684 {
2685 	va_list args;
2686 	int i;
2687 
2688 	va_start(args, fmt);
2689 	i = vsnprintf(buf, size, fmt, args);
2690 	va_end(args);
2691 
2692 	return i;
2693 }
2694 EXPORT_SYMBOL(snprintf);
2695 
2696 /**
2697  * scnprintf - Format a string and place it in a buffer
2698  * @buf: The buffer to place the result into
2699  * @size: The size of the buffer, including the trailing null space
2700  * @fmt: The format string to use
2701  * @...: Arguments for the format string
2702  *
2703  * The return value is the number of characters written into @buf not including
2704  * the trailing '\0'. If @size is == 0 the function returns 0.
2705  */
2706 
2707 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2708 {
2709 	va_list args;
2710 	int i;
2711 
2712 	va_start(args, fmt);
2713 	i = vscnprintf(buf, size, fmt, args);
2714 	va_end(args);
2715 
2716 	return i;
2717 }
2718 EXPORT_SYMBOL(scnprintf);
2719 
2720 /**
2721  * vsprintf - Format a string and place it in a buffer
2722  * @buf: The buffer to place the result into
2723  * @fmt: The format string to use
2724  * @args: Arguments for the format string
2725  *
2726  * The function returns the number of characters written
2727  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2728  * buffer overflows.
2729  *
2730  * If you're not already dealing with a va_list consider using sprintf().
2731  *
2732  * See the vsnprintf() documentation for format string extensions over C99.
2733  */
2734 int vsprintf(char *buf, const char *fmt, va_list args)
2735 {
2736 	return vsnprintf(buf, INT_MAX, fmt, args);
2737 }
2738 EXPORT_SYMBOL(vsprintf);
2739 
2740 /**
2741  * sprintf - Format a string and place it in a buffer
2742  * @buf: The buffer to place the result into
2743  * @fmt: The format string to use
2744  * @...: Arguments for the format string
2745  *
2746  * The function returns the number of characters written
2747  * into @buf. Use snprintf() or scnprintf() in order to avoid
2748  * buffer overflows.
2749  *
2750  * See the vsnprintf() documentation for format string extensions over C99.
2751  */
2752 int sprintf(char *buf, const char *fmt, ...)
2753 {
2754 	va_list args;
2755 	int i;
2756 
2757 	va_start(args, fmt);
2758 	i = vsnprintf(buf, INT_MAX, fmt, args);
2759 	va_end(args);
2760 
2761 	return i;
2762 }
2763 EXPORT_SYMBOL(sprintf);
2764 
2765 #ifdef CONFIG_BINARY_PRINTF
2766 /*
2767  * bprintf service:
2768  * vbin_printf() - VA arguments to binary data
2769  * bstr_printf() - Binary data to text string
2770  */
2771 
2772 /**
2773  * vbin_printf - Parse a format string and place args' binary value in a buffer
2774  * @bin_buf: The buffer to place args' binary value
2775  * @size: The size of the buffer(by words(32bits), not characters)
2776  * @fmt: The format string to use
2777  * @args: Arguments for the format string
2778  *
2779  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2780  * is skipped.
2781  *
2782  * The return value is the number of words(32bits) which would be generated for
2783  * the given input.
2784  *
2785  * NOTE:
2786  * If the return value is greater than @size, the resulting bin_buf is NOT
2787  * valid for bstr_printf().
2788  */
2789 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2790 {
2791 	struct printf_spec spec = {0};
2792 	char *str, *end;
2793 	int width;
2794 
2795 	str = (char *)bin_buf;
2796 	end = (char *)(bin_buf + size);
2797 
2798 #define save_arg(type)							\
2799 ({									\
2800 	unsigned long long value;					\
2801 	if (sizeof(type) == 8) {					\
2802 		unsigned long long val8;				\
2803 		str = PTR_ALIGN(str, sizeof(u32));			\
2804 		val8 = va_arg(args, unsigned long long);		\
2805 		if (str + sizeof(type) <= end) {			\
2806 			*(u32 *)str = *(u32 *)&val8;			\
2807 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
2808 		}							\
2809 		value = val8;						\
2810 	} else {							\
2811 		unsigned int val4;					\
2812 		str = PTR_ALIGN(str, sizeof(type));			\
2813 		val4 = va_arg(args, int);				\
2814 		if (str + sizeof(type) <= end)				\
2815 			*(typeof(type) *)str = (type)(long)val4;	\
2816 		value = (unsigned long long)val4;			\
2817 	}								\
2818 	str += sizeof(type);						\
2819 	value;								\
2820 })
2821 
2822 	while (*fmt) {
2823 		int read = format_decode(fmt, &spec);
2824 
2825 		fmt += read;
2826 
2827 		switch (spec.type) {
2828 		case FORMAT_TYPE_NONE:
2829 		case FORMAT_TYPE_PERCENT_CHAR:
2830 			break;
2831 		case FORMAT_TYPE_INVALID:
2832 			goto out;
2833 
2834 		case FORMAT_TYPE_WIDTH:
2835 		case FORMAT_TYPE_PRECISION:
2836 			width = (int)save_arg(int);
2837 			/* Pointers may require the width */
2838 			if (*fmt == 'p')
2839 				set_field_width(&spec, width);
2840 			break;
2841 
2842 		case FORMAT_TYPE_CHAR:
2843 			save_arg(char);
2844 			break;
2845 
2846 		case FORMAT_TYPE_STR: {
2847 			const char *save_str = va_arg(args, char *);
2848 			const char *err_msg;
2849 			size_t len;
2850 
2851 			err_msg = check_pointer_msg(save_str);
2852 			if (err_msg)
2853 				save_str = err_msg;
2854 
2855 			len = strlen(save_str) + 1;
2856 			if (str + len < end)
2857 				memcpy(str, save_str, len);
2858 			str += len;
2859 			break;
2860 		}
2861 
2862 		case FORMAT_TYPE_PTR:
2863 			/* Dereferenced pointers must be done now */
2864 			switch (*fmt) {
2865 			/* Dereference of functions is still OK */
2866 			case 'S':
2867 			case 's':
2868 			case 'x':
2869 			case 'K':
2870 			case 'e':
2871 				save_arg(void *);
2872 				break;
2873 			default:
2874 				if (!isalnum(*fmt)) {
2875 					save_arg(void *);
2876 					break;
2877 				}
2878 				str = pointer(fmt, str, end, va_arg(args, void *),
2879 					      spec);
2880 				if (str + 1 < end)
2881 					*str++ = '\0';
2882 				else
2883 					end[-1] = '\0'; /* Must be nul terminated */
2884 			}
2885 			/* skip all alphanumeric pointer suffixes */
2886 			while (isalnum(*fmt))
2887 				fmt++;
2888 			break;
2889 
2890 		default:
2891 			switch (spec.type) {
2892 
2893 			case FORMAT_TYPE_LONG_LONG:
2894 				save_arg(long long);
2895 				break;
2896 			case FORMAT_TYPE_ULONG:
2897 			case FORMAT_TYPE_LONG:
2898 				save_arg(unsigned long);
2899 				break;
2900 			case FORMAT_TYPE_SIZE_T:
2901 				save_arg(size_t);
2902 				break;
2903 			case FORMAT_TYPE_PTRDIFF:
2904 				save_arg(ptrdiff_t);
2905 				break;
2906 			case FORMAT_TYPE_UBYTE:
2907 			case FORMAT_TYPE_BYTE:
2908 				save_arg(char);
2909 				break;
2910 			case FORMAT_TYPE_USHORT:
2911 			case FORMAT_TYPE_SHORT:
2912 				save_arg(short);
2913 				break;
2914 			default:
2915 				save_arg(int);
2916 			}
2917 		}
2918 	}
2919 
2920 out:
2921 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2922 #undef save_arg
2923 }
2924 EXPORT_SYMBOL_GPL(vbin_printf);
2925 
2926 /**
2927  * bstr_printf - Format a string from binary arguments and place it in a buffer
2928  * @buf: The buffer to place the result into
2929  * @size: The size of the buffer, including the trailing null space
2930  * @fmt: The format string to use
2931  * @bin_buf: Binary arguments for the format string
2932  *
2933  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2934  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2935  * a binary buffer that generated by vbin_printf.
2936  *
2937  * The format follows C99 vsnprintf, but has some extensions:
2938  *  see vsnprintf comment for details.
2939  *
2940  * The return value is the number of characters which would
2941  * be generated for the given input, excluding the trailing
2942  * '\0', as per ISO C99. If you want to have the exact
2943  * number of characters written into @buf as return value
2944  * (not including the trailing '\0'), use vscnprintf(). If the
2945  * return is greater than or equal to @size, the resulting
2946  * string is truncated.
2947  */
2948 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2949 {
2950 	struct printf_spec spec = {0};
2951 	char *str, *end;
2952 	const char *args = (const char *)bin_buf;
2953 
2954 	if (WARN_ON_ONCE(size > INT_MAX))
2955 		return 0;
2956 
2957 	str = buf;
2958 	end = buf + size;
2959 
2960 #define get_arg(type)							\
2961 ({									\
2962 	typeof(type) value;						\
2963 	if (sizeof(type) == 8) {					\
2964 		args = PTR_ALIGN(args, sizeof(u32));			\
2965 		*(u32 *)&value = *(u32 *)args;				\
2966 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2967 	} else {							\
2968 		args = PTR_ALIGN(args, sizeof(type));			\
2969 		value = *(typeof(type) *)args;				\
2970 	}								\
2971 	args += sizeof(type);						\
2972 	value;								\
2973 })
2974 
2975 	/* Make sure end is always >= buf */
2976 	if (end < buf) {
2977 		end = ((void *)-1);
2978 		size = end - buf;
2979 	}
2980 
2981 	while (*fmt) {
2982 		const char *old_fmt = fmt;
2983 		int read = format_decode(fmt, &spec);
2984 
2985 		fmt += read;
2986 
2987 		switch (spec.type) {
2988 		case FORMAT_TYPE_NONE: {
2989 			int copy = read;
2990 			if (str < end) {
2991 				if (copy > end - str)
2992 					copy = end - str;
2993 				memcpy(str, old_fmt, copy);
2994 			}
2995 			str += read;
2996 			break;
2997 		}
2998 
2999 		case FORMAT_TYPE_WIDTH:
3000 			set_field_width(&spec, get_arg(int));
3001 			break;
3002 
3003 		case FORMAT_TYPE_PRECISION:
3004 			set_precision(&spec, get_arg(int));
3005 			break;
3006 
3007 		case FORMAT_TYPE_CHAR: {
3008 			char c;
3009 
3010 			if (!(spec.flags & LEFT)) {
3011 				while (--spec.field_width > 0) {
3012 					if (str < end)
3013 						*str = ' ';
3014 					++str;
3015 				}
3016 			}
3017 			c = (unsigned char) get_arg(char);
3018 			if (str < end)
3019 				*str = c;
3020 			++str;
3021 			while (--spec.field_width > 0) {
3022 				if (str < end)
3023 					*str = ' ';
3024 				++str;
3025 			}
3026 			break;
3027 		}
3028 
3029 		case FORMAT_TYPE_STR: {
3030 			const char *str_arg = args;
3031 			args += strlen(str_arg) + 1;
3032 			str = string(str, end, (char *)str_arg, spec);
3033 			break;
3034 		}
3035 
3036 		case FORMAT_TYPE_PTR: {
3037 			bool process = false;
3038 			int copy, len;
3039 			/* Non function dereferences were already done */
3040 			switch (*fmt) {
3041 			case 'S':
3042 			case 's':
3043 			case 'F':
3044 			case 'f':
3045 			case 'x':
3046 			case 'K':
3047 			case 'e':
3048 				process = true;
3049 				break;
3050 			default:
3051 				if (!isalnum(*fmt)) {
3052 					process = true;
3053 					break;
3054 				}
3055 				/* Pointer dereference was already processed */
3056 				if (str < end) {
3057 					len = copy = strlen(args);
3058 					if (copy > end - str)
3059 						copy = end - str;
3060 					memcpy(str, args, copy);
3061 					str += len;
3062 					args += len + 1;
3063 				}
3064 			}
3065 			if (process)
3066 				str = pointer(fmt, str, end, get_arg(void *), spec);
3067 
3068 			while (isalnum(*fmt))
3069 				fmt++;
3070 			break;
3071 		}
3072 
3073 		case FORMAT_TYPE_PERCENT_CHAR:
3074 			if (str < end)
3075 				*str = '%';
3076 			++str;
3077 			break;
3078 
3079 		case FORMAT_TYPE_INVALID:
3080 			goto out;
3081 
3082 		default: {
3083 			unsigned long long num;
3084 
3085 			switch (spec.type) {
3086 
3087 			case FORMAT_TYPE_LONG_LONG:
3088 				num = get_arg(long long);
3089 				break;
3090 			case FORMAT_TYPE_ULONG:
3091 			case FORMAT_TYPE_LONG:
3092 				num = get_arg(unsigned long);
3093 				break;
3094 			case FORMAT_TYPE_SIZE_T:
3095 				num = get_arg(size_t);
3096 				break;
3097 			case FORMAT_TYPE_PTRDIFF:
3098 				num = get_arg(ptrdiff_t);
3099 				break;
3100 			case FORMAT_TYPE_UBYTE:
3101 				num = get_arg(unsigned char);
3102 				break;
3103 			case FORMAT_TYPE_BYTE:
3104 				num = get_arg(signed char);
3105 				break;
3106 			case FORMAT_TYPE_USHORT:
3107 				num = get_arg(unsigned short);
3108 				break;
3109 			case FORMAT_TYPE_SHORT:
3110 				num = get_arg(short);
3111 				break;
3112 			case FORMAT_TYPE_UINT:
3113 				num = get_arg(unsigned int);
3114 				break;
3115 			default:
3116 				num = get_arg(int);
3117 			}
3118 
3119 			str = number(str, end, num, spec);
3120 		} /* default: */
3121 		} /* switch(spec.type) */
3122 	} /* while(*fmt) */
3123 
3124 out:
3125 	if (size > 0) {
3126 		if (str < end)
3127 			*str = '\0';
3128 		else
3129 			end[-1] = '\0';
3130 	}
3131 
3132 #undef get_arg
3133 
3134 	/* the trailing null byte doesn't count towards the total */
3135 	return str - buf;
3136 }
3137 EXPORT_SYMBOL_GPL(bstr_printf);
3138 
3139 /**
3140  * bprintf - Parse a format string and place args' binary value in a buffer
3141  * @bin_buf: The buffer to place args' binary value
3142  * @size: The size of the buffer(by words(32bits), not characters)
3143  * @fmt: The format string to use
3144  * @...: Arguments for the format string
3145  *
3146  * The function returns the number of words(u32) written
3147  * into @bin_buf.
3148  */
3149 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3150 {
3151 	va_list args;
3152 	int ret;
3153 
3154 	va_start(args, fmt);
3155 	ret = vbin_printf(bin_buf, size, fmt, args);
3156 	va_end(args);
3157 
3158 	return ret;
3159 }
3160 EXPORT_SYMBOL_GPL(bprintf);
3161 
3162 #endif /* CONFIG_BINARY_PRINTF */
3163 
3164 /**
3165  * vsscanf - Unformat a buffer into a list of arguments
3166  * @buf:	input buffer
3167  * @fmt:	format of buffer
3168  * @args:	arguments
3169  */
3170 int vsscanf(const char *buf, const char *fmt, va_list args)
3171 {
3172 	const char *str = buf;
3173 	char *next;
3174 	char digit;
3175 	int num = 0;
3176 	u8 qualifier;
3177 	unsigned int base;
3178 	union {
3179 		long long s;
3180 		unsigned long long u;
3181 	} val;
3182 	s16 field_width;
3183 	bool is_sign;
3184 
3185 	while (*fmt) {
3186 		/* skip any white space in format */
3187 		/* white space in format matchs any amount of
3188 		 * white space, including none, in the input.
3189 		 */
3190 		if (isspace(*fmt)) {
3191 			fmt = skip_spaces(++fmt);
3192 			str = skip_spaces(str);
3193 		}
3194 
3195 		/* anything that is not a conversion must match exactly */
3196 		if (*fmt != '%' && *fmt) {
3197 			if (*fmt++ != *str++)
3198 				break;
3199 			continue;
3200 		}
3201 
3202 		if (!*fmt)
3203 			break;
3204 		++fmt;
3205 
3206 		/* skip this conversion.
3207 		 * advance both strings to next white space
3208 		 */
3209 		if (*fmt == '*') {
3210 			if (!*str)
3211 				break;
3212 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3213 				/* '%*[' not yet supported, invalid format */
3214 				if (*fmt == '[')
3215 					return num;
3216 				fmt++;
3217 			}
3218 			while (!isspace(*str) && *str)
3219 				str++;
3220 			continue;
3221 		}
3222 
3223 		/* get field width */
3224 		field_width = -1;
3225 		if (isdigit(*fmt)) {
3226 			field_width = skip_atoi(&fmt);
3227 			if (field_width <= 0)
3228 				break;
3229 		}
3230 
3231 		/* get conversion qualifier */
3232 		qualifier = -1;
3233 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3234 		    *fmt == 'z') {
3235 			qualifier = *fmt++;
3236 			if (unlikely(qualifier == *fmt)) {
3237 				if (qualifier == 'h') {
3238 					qualifier = 'H';
3239 					fmt++;
3240 				} else if (qualifier == 'l') {
3241 					qualifier = 'L';
3242 					fmt++;
3243 				}
3244 			}
3245 		}
3246 
3247 		if (!*fmt)
3248 			break;
3249 
3250 		if (*fmt == 'n') {
3251 			/* return number of characters read so far */
3252 			*va_arg(args, int *) = str - buf;
3253 			++fmt;
3254 			continue;
3255 		}
3256 
3257 		if (!*str)
3258 			break;
3259 
3260 		base = 10;
3261 		is_sign = false;
3262 
3263 		switch (*fmt++) {
3264 		case 'c':
3265 		{
3266 			char *s = (char *)va_arg(args, char*);
3267 			if (field_width == -1)
3268 				field_width = 1;
3269 			do {
3270 				*s++ = *str++;
3271 			} while (--field_width > 0 && *str);
3272 			num++;
3273 		}
3274 		continue;
3275 		case 's':
3276 		{
3277 			char *s = (char *)va_arg(args, char *);
3278 			if (field_width == -1)
3279 				field_width = SHRT_MAX;
3280 			/* first, skip leading white space in buffer */
3281 			str = skip_spaces(str);
3282 
3283 			/* now copy until next white space */
3284 			while (*str && !isspace(*str) && field_width--)
3285 				*s++ = *str++;
3286 			*s = '\0';
3287 			num++;
3288 		}
3289 		continue;
3290 		/*
3291 		 * Warning: This implementation of the '[' conversion specifier
3292 		 * deviates from its glibc counterpart in the following ways:
3293 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3294 		 *     character
3295 		 * (2) It cannot match the closing bracket ']' itself
3296 		 * (3) A field width is required
3297 		 * (4) '%*[' (discard matching input) is currently not supported
3298 		 *
3299 		 * Example usage:
3300 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3301 		 *		buf1, buf2, buf3);
3302 		 * if (ret < 3)
3303 		 *    // etc..
3304 		 */
3305 		case '[':
3306 		{
3307 			char *s = (char *)va_arg(args, char *);
3308 			DECLARE_BITMAP(set, 256) = {0};
3309 			unsigned int len = 0;
3310 			bool negate = (*fmt == '^');
3311 
3312 			/* field width is required */
3313 			if (field_width == -1)
3314 				return num;
3315 
3316 			if (negate)
3317 				++fmt;
3318 
3319 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3320 				set_bit((u8)*fmt, set);
3321 
3322 			/* no ']' or no character set found */
3323 			if (!*fmt || !len)
3324 				return num;
3325 			++fmt;
3326 
3327 			if (negate) {
3328 				bitmap_complement(set, set, 256);
3329 				/* exclude null '\0' byte */
3330 				clear_bit(0, set);
3331 			}
3332 
3333 			/* match must be non-empty */
3334 			if (!test_bit((u8)*str, set))
3335 				return num;
3336 
3337 			while (test_bit((u8)*str, set) && field_width--)
3338 				*s++ = *str++;
3339 			*s = '\0';
3340 			++num;
3341 		}
3342 		continue;
3343 		case 'o':
3344 			base = 8;
3345 			break;
3346 		case 'x':
3347 		case 'X':
3348 			base = 16;
3349 			break;
3350 		case 'i':
3351 			base = 0;
3352 			/* fall through */
3353 		case 'd':
3354 			is_sign = true;
3355 			/* fall through */
3356 		case 'u':
3357 			break;
3358 		case '%':
3359 			/* looking for '%' in str */
3360 			if (*str++ != '%')
3361 				return num;
3362 			continue;
3363 		default:
3364 			/* invalid format; stop here */
3365 			return num;
3366 		}
3367 
3368 		/* have some sort of integer conversion.
3369 		 * first, skip white space in buffer.
3370 		 */
3371 		str = skip_spaces(str);
3372 
3373 		digit = *str;
3374 		if (is_sign && digit == '-')
3375 			digit = *(str + 1);
3376 
3377 		if (!digit
3378 		    || (base == 16 && !isxdigit(digit))
3379 		    || (base == 10 && !isdigit(digit))
3380 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
3381 		    || (base == 0 && !isdigit(digit)))
3382 			break;
3383 
3384 		if (is_sign)
3385 			val.s = qualifier != 'L' ?
3386 				simple_strtol(str, &next, base) :
3387 				simple_strtoll(str, &next, base);
3388 		else
3389 			val.u = qualifier != 'L' ?
3390 				simple_strtoul(str, &next, base) :
3391 				simple_strtoull(str, &next, base);
3392 
3393 		if (field_width > 0 && next - str > field_width) {
3394 			if (base == 0)
3395 				_parse_integer_fixup_radix(str, &base);
3396 			while (next - str > field_width) {
3397 				if (is_sign)
3398 					val.s = div_s64(val.s, base);
3399 				else
3400 					val.u = div_u64(val.u, base);
3401 				--next;
3402 			}
3403 		}
3404 
3405 		switch (qualifier) {
3406 		case 'H':	/* that's 'hh' in format */
3407 			if (is_sign)
3408 				*va_arg(args, signed char *) = val.s;
3409 			else
3410 				*va_arg(args, unsigned char *) = val.u;
3411 			break;
3412 		case 'h':
3413 			if (is_sign)
3414 				*va_arg(args, short *) = val.s;
3415 			else
3416 				*va_arg(args, unsigned short *) = val.u;
3417 			break;
3418 		case 'l':
3419 			if (is_sign)
3420 				*va_arg(args, long *) = val.s;
3421 			else
3422 				*va_arg(args, unsigned long *) = val.u;
3423 			break;
3424 		case 'L':
3425 			if (is_sign)
3426 				*va_arg(args, long long *) = val.s;
3427 			else
3428 				*va_arg(args, unsigned long long *) = val.u;
3429 			break;
3430 		case 'z':
3431 			*va_arg(args, size_t *) = val.u;
3432 			break;
3433 		default:
3434 			if (is_sign)
3435 				*va_arg(args, int *) = val.s;
3436 			else
3437 				*va_arg(args, unsigned int *) = val.u;
3438 			break;
3439 		}
3440 		num++;
3441 
3442 		if (!next)
3443 			break;
3444 		str = next;
3445 	}
3446 
3447 	return num;
3448 }
3449 EXPORT_SYMBOL(vsscanf);
3450 
3451 /**
3452  * sscanf - Unformat a buffer into a list of arguments
3453  * @buf:	input buffer
3454  * @fmt:	formatting of buffer
3455  * @...:	resulting arguments
3456  */
3457 int sscanf(const char *buf, const char *fmt, ...)
3458 {
3459 	va_list args;
3460 	int i;
3461 
3462 	va_start(args, fmt);
3463 	i = vsscanf(buf, fmt, args);
3464 	va_end(args);
3465 
3466 	return i;
3467 }
3468 EXPORT_SYMBOL(sscanf);
3469