xref: /openbmc/linux/lib/vsprintf.c (revision 69fad28c)
1 /*
2  *  linux/lib/vsprintf.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6 
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8 /*
9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
10  */
11 
12 /*
13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
14  * - changed to provide snprintf and vsnprintf functions
15  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
16  * - scnprintf and vscnprintf
17  */
18 
19 #include <stdarg.h>
20 #include <linux/clk.h>
21 #include <linux/clk-provider.h>
22 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
23 #include <linux/types.h>
24 #include <linux/string.h>
25 #include <linux/ctype.h>
26 #include <linux/kernel.h>
27 #include <linux/kallsyms.h>
28 #include <linux/math64.h>
29 #include <linux/uaccess.h>
30 #include <linux/ioport.h>
31 #include <linux/dcache.h>
32 #include <linux/cred.h>
33 #include <linux/rtc.h>
34 #include <linux/uuid.h>
35 #include <linux/of.h>
36 #include <net/addrconf.h>
37 #include <linux/siphash.h>
38 #include <linux/compiler.h>
39 #ifdef CONFIG_BLOCK
40 #include <linux/blkdev.h>
41 #endif
42 
43 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
44 
45 #include <asm/page.h>		/* for PAGE_SIZE */
46 #include <asm/byteorder.h>	/* cpu_to_le16 */
47 
48 #include <linux/string_helpers.h>
49 #include "kstrtox.h"
50 
51 /**
52  * simple_strtoull - convert a string to an unsigned long long
53  * @cp: The start of the string
54  * @endp: A pointer to the end of the parsed string will be placed here
55  * @base: The number base to use
56  *
57  * This function is obsolete. Please use kstrtoull instead.
58  */
59 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
60 {
61 	unsigned long long result;
62 	unsigned int rv;
63 
64 	cp = _parse_integer_fixup_radix(cp, &base);
65 	rv = _parse_integer(cp, base, &result);
66 	/* FIXME */
67 	cp += (rv & ~KSTRTOX_OVERFLOW);
68 
69 	if (endp)
70 		*endp = (char *)cp;
71 
72 	return result;
73 }
74 EXPORT_SYMBOL(simple_strtoull);
75 
76 /**
77  * simple_strtoul - convert a string to an unsigned long
78  * @cp: The start of the string
79  * @endp: A pointer to the end of the parsed string will be placed here
80  * @base: The number base to use
81  *
82  * This function is obsolete. Please use kstrtoul instead.
83  */
84 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
85 {
86 	return simple_strtoull(cp, endp, base);
87 }
88 EXPORT_SYMBOL(simple_strtoul);
89 
90 /**
91  * simple_strtol - convert a string to a signed long
92  * @cp: The start of the string
93  * @endp: A pointer to the end of the parsed string will be placed here
94  * @base: The number base to use
95  *
96  * This function is obsolete. Please use kstrtol instead.
97  */
98 long simple_strtol(const char *cp, char **endp, unsigned int base)
99 {
100 	if (*cp == '-')
101 		return -simple_strtoul(cp + 1, endp, base);
102 
103 	return simple_strtoul(cp, endp, base);
104 }
105 EXPORT_SYMBOL(simple_strtol);
106 
107 /**
108  * simple_strtoll - convert a string to a signed long long
109  * @cp: The start of the string
110  * @endp: A pointer to the end of the parsed string will be placed here
111  * @base: The number base to use
112  *
113  * This function is obsolete. Please use kstrtoll instead.
114  */
115 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
116 {
117 	if (*cp == '-')
118 		return -simple_strtoull(cp + 1, endp, base);
119 
120 	return simple_strtoull(cp, endp, base);
121 }
122 EXPORT_SYMBOL(simple_strtoll);
123 
124 static noinline_for_stack
125 int skip_atoi(const char **s)
126 {
127 	int i = 0;
128 
129 	do {
130 		i = i*10 + *((*s)++) - '0';
131 	} while (isdigit(**s));
132 
133 	return i;
134 }
135 
136 /*
137  * Decimal conversion is by far the most typical, and is used for
138  * /proc and /sys data. This directly impacts e.g. top performance
139  * with many processes running. We optimize it for speed by emitting
140  * two characters at a time, using a 200 byte lookup table. This
141  * roughly halves the number of multiplications compared to computing
142  * the digits one at a time. Implementation strongly inspired by the
143  * previous version, which in turn used ideas described at
144  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
145  * from the author, Douglas W. Jones).
146  *
147  * It turns out there is precisely one 26 bit fixed-point
148  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
149  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
150  * range happens to be somewhat larger (x <= 1073741898), but that's
151  * irrelevant for our purpose.
152  *
153  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
154  * need a 32x32->64 bit multiply, so we simply use the same constant.
155  *
156  * For dividing a number in the range [100, 10^4-1] by 100, there are
157  * several options. The simplest is (x * 0x147b) >> 19, which is valid
158  * for all x <= 43698.
159  */
160 
161 static const u16 decpair[100] = {
162 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
163 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
164 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
165 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
166 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
167 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
168 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
169 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
170 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
171 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
172 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
173 #undef _
174 };
175 
176 /*
177  * This will print a single '0' even if r == 0, since we would
178  * immediately jump to out_r where two 0s would be written but only
179  * one of them accounted for in buf. This is needed by ip4_string
180  * below. All other callers pass a non-zero value of r.
181 */
182 static noinline_for_stack
183 char *put_dec_trunc8(char *buf, unsigned r)
184 {
185 	unsigned q;
186 
187 	/* 1 <= r < 10^8 */
188 	if (r < 100)
189 		goto out_r;
190 
191 	/* 100 <= r < 10^8 */
192 	q = (r * (u64)0x28f5c29) >> 32;
193 	*((u16 *)buf) = decpair[r - 100*q];
194 	buf += 2;
195 
196 	/* 1 <= q < 10^6 */
197 	if (q < 100)
198 		goto out_q;
199 
200 	/*  100 <= q < 10^6 */
201 	r = (q * (u64)0x28f5c29) >> 32;
202 	*((u16 *)buf) = decpair[q - 100*r];
203 	buf += 2;
204 
205 	/* 1 <= r < 10^4 */
206 	if (r < 100)
207 		goto out_r;
208 
209 	/* 100 <= r < 10^4 */
210 	q = (r * 0x147b) >> 19;
211 	*((u16 *)buf) = decpair[r - 100*q];
212 	buf += 2;
213 out_q:
214 	/* 1 <= q < 100 */
215 	r = q;
216 out_r:
217 	/* 1 <= r < 100 */
218 	*((u16 *)buf) = decpair[r];
219 	buf += r < 10 ? 1 : 2;
220 	return buf;
221 }
222 
223 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
224 static noinline_for_stack
225 char *put_dec_full8(char *buf, unsigned r)
226 {
227 	unsigned q;
228 
229 	/* 0 <= r < 10^8 */
230 	q = (r * (u64)0x28f5c29) >> 32;
231 	*((u16 *)buf) = decpair[r - 100*q];
232 	buf += 2;
233 
234 	/* 0 <= q < 10^6 */
235 	r = (q * (u64)0x28f5c29) >> 32;
236 	*((u16 *)buf) = decpair[q - 100*r];
237 	buf += 2;
238 
239 	/* 0 <= r < 10^4 */
240 	q = (r * 0x147b) >> 19;
241 	*((u16 *)buf) = decpair[r - 100*q];
242 	buf += 2;
243 
244 	/* 0 <= q < 100 */
245 	*((u16 *)buf) = decpair[q];
246 	buf += 2;
247 	return buf;
248 }
249 
250 static noinline_for_stack
251 char *put_dec(char *buf, unsigned long long n)
252 {
253 	if (n >= 100*1000*1000)
254 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
255 	/* 1 <= n <= 1.6e11 */
256 	if (n >= 100*1000*1000)
257 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
258 	/* 1 <= n < 1e8 */
259 	return put_dec_trunc8(buf, n);
260 }
261 
262 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
263 
264 static void
265 put_dec_full4(char *buf, unsigned r)
266 {
267 	unsigned q;
268 
269 	/* 0 <= r < 10^4 */
270 	q = (r * 0x147b) >> 19;
271 	*((u16 *)buf) = decpair[r - 100*q];
272 	buf += 2;
273 	/* 0 <= q < 100 */
274 	*((u16 *)buf) = decpair[q];
275 }
276 
277 /*
278  * Call put_dec_full4 on x % 10000, return x / 10000.
279  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
280  * holds for all x < 1,128,869,999.  The largest value this
281  * helper will ever be asked to convert is 1,125,520,955.
282  * (second call in the put_dec code, assuming n is all-ones).
283  */
284 static noinline_for_stack
285 unsigned put_dec_helper4(char *buf, unsigned x)
286 {
287         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
288 
289         put_dec_full4(buf, x - q * 10000);
290         return q;
291 }
292 
293 /* Based on code by Douglas W. Jones found at
294  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
295  * (with permission from the author).
296  * Performs no 64-bit division and hence should be fast on 32-bit machines.
297  */
298 static
299 char *put_dec(char *buf, unsigned long long n)
300 {
301 	uint32_t d3, d2, d1, q, h;
302 
303 	if (n < 100*1000*1000)
304 		return put_dec_trunc8(buf, n);
305 
306 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
307 	h   = (n >> 32);
308 	d2  = (h      ) & 0xffff;
309 	d3  = (h >> 16); /* implicit "& 0xffff" */
310 
311 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
312 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
313 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
314 	q = put_dec_helper4(buf, q);
315 
316 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
317 	q = put_dec_helper4(buf+4, q);
318 
319 	q += 4749 * d3 + 42 * d2;
320 	q = put_dec_helper4(buf+8, q);
321 
322 	q += 281 * d3;
323 	buf += 12;
324 	if (q)
325 		buf = put_dec_trunc8(buf, q);
326 	else while (buf[-1] == '0')
327 		--buf;
328 
329 	return buf;
330 }
331 
332 #endif
333 
334 /*
335  * Convert passed number to decimal string.
336  * Returns the length of string.  On buffer overflow, returns 0.
337  *
338  * If speed is not important, use snprintf(). It's easy to read the code.
339  */
340 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
341 {
342 	/* put_dec requires 2-byte alignment of the buffer. */
343 	char tmp[sizeof(num) * 3] __aligned(2);
344 	int idx, len;
345 
346 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
347 	if (num <= 9) {
348 		tmp[0] = '0' + num;
349 		len = 1;
350 	} else {
351 		len = put_dec(tmp, num) - tmp;
352 	}
353 
354 	if (len > size || width > size)
355 		return 0;
356 
357 	if (width > len) {
358 		width = width - len;
359 		for (idx = 0; idx < width; idx++)
360 			buf[idx] = ' ';
361 	} else {
362 		width = 0;
363 	}
364 
365 	for (idx = 0; idx < len; ++idx)
366 		buf[idx + width] = tmp[len - idx - 1];
367 
368 	return len + width;
369 }
370 
371 #define SIGN	1		/* unsigned/signed, must be 1 */
372 #define LEFT	2		/* left justified */
373 #define PLUS	4		/* show plus */
374 #define SPACE	8		/* space if plus */
375 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
376 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
377 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
378 
379 enum format_type {
380 	FORMAT_TYPE_NONE, /* Just a string part */
381 	FORMAT_TYPE_WIDTH,
382 	FORMAT_TYPE_PRECISION,
383 	FORMAT_TYPE_CHAR,
384 	FORMAT_TYPE_STR,
385 	FORMAT_TYPE_PTR,
386 	FORMAT_TYPE_PERCENT_CHAR,
387 	FORMAT_TYPE_INVALID,
388 	FORMAT_TYPE_LONG_LONG,
389 	FORMAT_TYPE_ULONG,
390 	FORMAT_TYPE_LONG,
391 	FORMAT_TYPE_UBYTE,
392 	FORMAT_TYPE_BYTE,
393 	FORMAT_TYPE_USHORT,
394 	FORMAT_TYPE_SHORT,
395 	FORMAT_TYPE_UINT,
396 	FORMAT_TYPE_INT,
397 	FORMAT_TYPE_SIZE_T,
398 	FORMAT_TYPE_PTRDIFF
399 };
400 
401 struct printf_spec {
402 	unsigned int	type:8;		/* format_type enum */
403 	signed int	field_width:24;	/* width of output field */
404 	unsigned int	flags:8;	/* flags to number() */
405 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
406 	signed int	precision:16;	/* # of digits/chars */
407 } __packed;
408 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
409 #define PRECISION_MAX ((1 << 15) - 1)
410 
411 static noinline_for_stack
412 char *number(char *buf, char *end, unsigned long long num,
413 	     struct printf_spec spec)
414 {
415 	/* put_dec requires 2-byte alignment of the buffer. */
416 	char tmp[3 * sizeof(num)] __aligned(2);
417 	char sign;
418 	char locase;
419 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
420 	int i;
421 	bool is_zero = num == 0LL;
422 	int field_width = spec.field_width;
423 	int precision = spec.precision;
424 
425 	BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
426 
427 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
428 	 * produces same digits or (maybe lowercased) letters */
429 	locase = (spec.flags & SMALL);
430 	if (spec.flags & LEFT)
431 		spec.flags &= ~ZEROPAD;
432 	sign = 0;
433 	if (spec.flags & SIGN) {
434 		if ((signed long long)num < 0) {
435 			sign = '-';
436 			num = -(signed long long)num;
437 			field_width--;
438 		} else if (spec.flags & PLUS) {
439 			sign = '+';
440 			field_width--;
441 		} else if (spec.flags & SPACE) {
442 			sign = ' ';
443 			field_width--;
444 		}
445 	}
446 	if (need_pfx) {
447 		if (spec.base == 16)
448 			field_width -= 2;
449 		else if (!is_zero)
450 			field_width--;
451 	}
452 
453 	/* generate full string in tmp[], in reverse order */
454 	i = 0;
455 	if (num < spec.base)
456 		tmp[i++] = hex_asc_upper[num] | locase;
457 	else if (spec.base != 10) { /* 8 or 16 */
458 		int mask = spec.base - 1;
459 		int shift = 3;
460 
461 		if (spec.base == 16)
462 			shift = 4;
463 		do {
464 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
465 			num >>= shift;
466 		} while (num);
467 	} else { /* base 10 */
468 		i = put_dec(tmp, num) - tmp;
469 	}
470 
471 	/* printing 100 using %2d gives "100", not "00" */
472 	if (i > precision)
473 		precision = i;
474 	/* leading space padding */
475 	field_width -= precision;
476 	if (!(spec.flags & (ZEROPAD | LEFT))) {
477 		while (--field_width >= 0) {
478 			if (buf < end)
479 				*buf = ' ';
480 			++buf;
481 		}
482 	}
483 	/* sign */
484 	if (sign) {
485 		if (buf < end)
486 			*buf = sign;
487 		++buf;
488 	}
489 	/* "0x" / "0" prefix */
490 	if (need_pfx) {
491 		if (spec.base == 16 || !is_zero) {
492 			if (buf < end)
493 				*buf = '0';
494 			++buf;
495 		}
496 		if (spec.base == 16) {
497 			if (buf < end)
498 				*buf = ('X' | locase);
499 			++buf;
500 		}
501 	}
502 	/* zero or space padding */
503 	if (!(spec.flags & LEFT)) {
504 		char c = ' ' + (spec.flags & ZEROPAD);
505 		BUILD_BUG_ON(' ' + ZEROPAD != '0');
506 		while (--field_width >= 0) {
507 			if (buf < end)
508 				*buf = c;
509 			++buf;
510 		}
511 	}
512 	/* hmm even more zero padding? */
513 	while (i <= --precision) {
514 		if (buf < end)
515 			*buf = '0';
516 		++buf;
517 	}
518 	/* actual digits of result */
519 	while (--i >= 0) {
520 		if (buf < end)
521 			*buf = tmp[i];
522 		++buf;
523 	}
524 	/* trailing space padding */
525 	while (--field_width >= 0) {
526 		if (buf < end)
527 			*buf = ' ';
528 		++buf;
529 	}
530 
531 	return buf;
532 }
533 
534 static noinline_for_stack
535 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
536 {
537 	struct printf_spec spec;
538 
539 	spec.type = FORMAT_TYPE_PTR;
540 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
541 	spec.flags = SPECIAL | SMALL | ZEROPAD;
542 	spec.base = 16;
543 	spec.precision = -1;
544 
545 	return number(buf, end, num, spec);
546 }
547 
548 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
549 {
550 	size_t size;
551 	if (buf >= end)	/* nowhere to put anything */
552 		return;
553 	size = end - buf;
554 	if (size <= spaces) {
555 		memset(buf, ' ', size);
556 		return;
557 	}
558 	if (len) {
559 		if (len > size - spaces)
560 			len = size - spaces;
561 		memmove(buf + spaces, buf, len);
562 	}
563 	memset(buf, ' ', spaces);
564 }
565 
566 /*
567  * Handle field width padding for a string.
568  * @buf: current buffer position
569  * @n: length of string
570  * @end: end of output buffer
571  * @spec: for field width and flags
572  * Returns: new buffer position after padding.
573  */
574 static noinline_for_stack
575 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
576 {
577 	unsigned spaces;
578 
579 	if (likely(n >= spec.field_width))
580 		return buf;
581 	/* we want to pad the sucker */
582 	spaces = spec.field_width - n;
583 	if (!(spec.flags & LEFT)) {
584 		move_right(buf - n, end, n, spaces);
585 		return buf + spaces;
586 	}
587 	while (spaces--) {
588 		if (buf < end)
589 			*buf = ' ';
590 		++buf;
591 	}
592 	return buf;
593 }
594 
595 static noinline_for_stack
596 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
597 {
598 	int len = 0;
599 	size_t lim = spec.precision;
600 
601 	if ((unsigned long)s < PAGE_SIZE)
602 		s = "(null)";
603 
604 	while (lim--) {
605 		char c = *s++;
606 		if (!c)
607 			break;
608 		if (buf < end)
609 			*buf = c;
610 		++buf;
611 		++len;
612 	}
613 	return widen_string(buf, len, end, spec);
614 }
615 
616 static noinline_for_stack
617 char *pointer_string(char *buf, char *end, const void *ptr,
618 		     struct printf_spec spec)
619 {
620 	spec.base = 16;
621 	spec.flags |= SMALL;
622 	if (spec.field_width == -1) {
623 		spec.field_width = 2 * sizeof(ptr);
624 		spec.flags |= ZEROPAD;
625 	}
626 
627 	return number(buf, end, (unsigned long int)ptr, spec);
628 }
629 
630 /* Make pointers available for printing early in the boot sequence. */
631 static int debug_boot_weak_hash __ro_after_init;
632 
633 static int __init debug_boot_weak_hash_enable(char *str)
634 {
635 	debug_boot_weak_hash = 1;
636 	pr_info("debug_boot_weak_hash enabled\n");
637 	return 0;
638 }
639 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
640 
641 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
642 static siphash_key_t ptr_key __read_mostly;
643 
644 static void enable_ptr_key_workfn(struct work_struct *work)
645 {
646 	get_random_bytes(&ptr_key, sizeof(ptr_key));
647 	/* Needs to run from preemptible context */
648 	static_branch_disable(&not_filled_random_ptr_key);
649 }
650 
651 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
652 
653 static void fill_random_ptr_key(struct random_ready_callback *unused)
654 {
655 	/* This may be in an interrupt handler. */
656 	queue_work(system_unbound_wq, &enable_ptr_key_work);
657 }
658 
659 static struct random_ready_callback random_ready = {
660 	.func = fill_random_ptr_key
661 };
662 
663 static int __init initialize_ptr_random(void)
664 {
665 	int key_size = sizeof(ptr_key);
666 	int ret;
667 
668 	/* Use hw RNG if available. */
669 	if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
670 		static_branch_disable(&not_filled_random_ptr_key);
671 		return 0;
672 	}
673 
674 	ret = add_random_ready_callback(&random_ready);
675 	if (!ret) {
676 		return 0;
677 	} else if (ret == -EALREADY) {
678 		/* This is in preemptible context */
679 		enable_ptr_key_workfn(&enable_ptr_key_work);
680 		return 0;
681 	}
682 
683 	return ret;
684 }
685 early_initcall(initialize_ptr_random);
686 
687 /* Maps a pointer to a 32 bit unique identifier. */
688 static char *ptr_to_id(char *buf, char *end, const void *ptr,
689 		       struct printf_spec spec)
690 {
691 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
692 	unsigned long hashval;
693 
694 	/* When debugging early boot use non-cryptographically secure hash. */
695 	if (unlikely(debug_boot_weak_hash)) {
696 		hashval = hash_long((unsigned long)ptr, 32);
697 		return pointer_string(buf, end, (const void *)hashval, spec);
698 	}
699 
700 	if (static_branch_unlikely(&not_filled_random_ptr_key)) {
701 		spec.field_width = 2 * sizeof(ptr);
702 		/* string length must be less than default_width */
703 		return string(buf, end, str, spec);
704 	}
705 
706 #ifdef CONFIG_64BIT
707 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
708 	/*
709 	 * Mask off the first 32 bits, this makes explicit that we have
710 	 * modified the address (and 32 bits is plenty for a unique ID).
711 	 */
712 	hashval = hashval & 0xffffffff;
713 #else
714 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
715 #endif
716 	return pointer_string(buf, end, (const void *)hashval, spec);
717 }
718 
719 static noinline_for_stack
720 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
721 		  const char *fmt)
722 {
723 	const char *array[4], *s;
724 	const struct dentry *p;
725 	int depth;
726 	int i, n;
727 
728 	switch (fmt[1]) {
729 		case '2': case '3': case '4':
730 			depth = fmt[1] - '0';
731 			break;
732 		default:
733 			depth = 1;
734 	}
735 
736 	rcu_read_lock();
737 	for (i = 0; i < depth; i++, d = p) {
738 		p = READ_ONCE(d->d_parent);
739 		array[i] = READ_ONCE(d->d_name.name);
740 		if (p == d) {
741 			if (i)
742 				array[i] = "";
743 			i++;
744 			break;
745 		}
746 	}
747 	s = array[--i];
748 	for (n = 0; n != spec.precision; n++, buf++) {
749 		char c = *s++;
750 		if (!c) {
751 			if (!i)
752 				break;
753 			c = '/';
754 			s = array[--i];
755 		}
756 		if (buf < end)
757 			*buf = c;
758 	}
759 	rcu_read_unlock();
760 	return widen_string(buf, n, end, spec);
761 }
762 
763 #ifdef CONFIG_BLOCK
764 static noinline_for_stack
765 char *bdev_name(char *buf, char *end, struct block_device *bdev,
766 		struct printf_spec spec, const char *fmt)
767 {
768 	struct gendisk *hd = bdev->bd_disk;
769 
770 	buf = string(buf, end, hd->disk_name, spec);
771 	if (bdev->bd_part->partno) {
772 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
773 			if (buf < end)
774 				*buf = 'p';
775 			buf++;
776 		}
777 		buf = number(buf, end, bdev->bd_part->partno, spec);
778 	}
779 	return buf;
780 }
781 #endif
782 
783 static noinline_for_stack
784 char *symbol_string(char *buf, char *end, void *ptr,
785 		    struct printf_spec spec, const char *fmt)
786 {
787 	unsigned long value;
788 #ifdef CONFIG_KALLSYMS
789 	char sym[KSYM_SYMBOL_LEN];
790 #endif
791 
792 	if (fmt[1] == 'R')
793 		ptr = __builtin_extract_return_addr(ptr);
794 	value = (unsigned long)ptr;
795 
796 #ifdef CONFIG_KALLSYMS
797 	if (*fmt == 'B')
798 		sprint_backtrace(sym, value);
799 	else if (*fmt != 'f' && *fmt != 's')
800 		sprint_symbol(sym, value);
801 	else
802 		sprint_symbol_no_offset(sym, value);
803 
804 	return string(buf, end, sym, spec);
805 #else
806 	return special_hex_number(buf, end, value, sizeof(void *));
807 #endif
808 }
809 
810 static const struct printf_spec default_str_spec = {
811 	.field_width = -1,
812 	.precision = -1,
813 };
814 
815 static const struct printf_spec default_flag_spec = {
816 	.base = 16,
817 	.precision = -1,
818 	.flags = SPECIAL | SMALL,
819 };
820 
821 static const struct printf_spec default_dec_spec = {
822 	.base = 10,
823 	.precision = -1,
824 };
825 
826 static const struct printf_spec default_dec02_spec = {
827 	.base = 10,
828 	.field_width = 2,
829 	.precision = -1,
830 	.flags = ZEROPAD,
831 };
832 
833 static const struct printf_spec default_dec04_spec = {
834 	.base = 10,
835 	.field_width = 4,
836 	.precision = -1,
837 	.flags = ZEROPAD,
838 };
839 
840 static noinline_for_stack
841 char *resource_string(char *buf, char *end, struct resource *res,
842 		      struct printf_spec spec, const char *fmt)
843 {
844 #ifndef IO_RSRC_PRINTK_SIZE
845 #define IO_RSRC_PRINTK_SIZE	6
846 #endif
847 
848 #ifndef MEM_RSRC_PRINTK_SIZE
849 #define MEM_RSRC_PRINTK_SIZE	10
850 #endif
851 	static const struct printf_spec io_spec = {
852 		.base = 16,
853 		.field_width = IO_RSRC_PRINTK_SIZE,
854 		.precision = -1,
855 		.flags = SPECIAL | SMALL | ZEROPAD,
856 	};
857 	static const struct printf_spec mem_spec = {
858 		.base = 16,
859 		.field_width = MEM_RSRC_PRINTK_SIZE,
860 		.precision = -1,
861 		.flags = SPECIAL | SMALL | ZEROPAD,
862 	};
863 	static const struct printf_spec bus_spec = {
864 		.base = 16,
865 		.field_width = 2,
866 		.precision = -1,
867 		.flags = SMALL | ZEROPAD,
868 	};
869 	static const struct printf_spec str_spec = {
870 		.field_width = -1,
871 		.precision = 10,
872 		.flags = LEFT,
873 	};
874 
875 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
876 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
877 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
878 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
879 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
880 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
881 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
882 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
883 
884 	char *p = sym, *pend = sym + sizeof(sym);
885 	int decode = (fmt[0] == 'R') ? 1 : 0;
886 	const struct printf_spec *specp;
887 
888 	*p++ = '[';
889 	if (res->flags & IORESOURCE_IO) {
890 		p = string(p, pend, "io  ", str_spec);
891 		specp = &io_spec;
892 	} else if (res->flags & IORESOURCE_MEM) {
893 		p = string(p, pend, "mem ", str_spec);
894 		specp = &mem_spec;
895 	} else if (res->flags & IORESOURCE_IRQ) {
896 		p = string(p, pend, "irq ", str_spec);
897 		specp = &default_dec_spec;
898 	} else if (res->flags & IORESOURCE_DMA) {
899 		p = string(p, pend, "dma ", str_spec);
900 		specp = &default_dec_spec;
901 	} else if (res->flags & IORESOURCE_BUS) {
902 		p = string(p, pend, "bus ", str_spec);
903 		specp = &bus_spec;
904 	} else {
905 		p = string(p, pend, "??? ", str_spec);
906 		specp = &mem_spec;
907 		decode = 0;
908 	}
909 	if (decode && res->flags & IORESOURCE_UNSET) {
910 		p = string(p, pend, "size ", str_spec);
911 		p = number(p, pend, resource_size(res), *specp);
912 	} else {
913 		p = number(p, pend, res->start, *specp);
914 		if (res->start != res->end) {
915 			*p++ = '-';
916 			p = number(p, pend, res->end, *specp);
917 		}
918 	}
919 	if (decode) {
920 		if (res->flags & IORESOURCE_MEM_64)
921 			p = string(p, pend, " 64bit", str_spec);
922 		if (res->flags & IORESOURCE_PREFETCH)
923 			p = string(p, pend, " pref", str_spec);
924 		if (res->flags & IORESOURCE_WINDOW)
925 			p = string(p, pend, " window", str_spec);
926 		if (res->flags & IORESOURCE_DISABLED)
927 			p = string(p, pend, " disabled", str_spec);
928 	} else {
929 		p = string(p, pend, " flags ", str_spec);
930 		p = number(p, pend, res->flags, default_flag_spec);
931 	}
932 	*p++ = ']';
933 	*p = '\0';
934 
935 	return string(buf, end, sym, spec);
936 }
937 
938 static noinline_for_stack
939 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
940 		 const char *fmt)
941 {
942 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
943 				   negative value, fallback to the default */
944 	char separator;
945 
946 	if (spec.field_width == 0)
947 		/* nothing to print */
948 		return buf;
949 
950 	if (ZERO_OR_NULL_PTR(addr))
951 		/* NULL pointer */
952 		return string(buf, end, NULL, spec);
953 
954 	switch (fmt[1]) {
955 	case 'C':
956 		separator = ':';
957 		break;
958 	case 'D':
959 		separator = '-';
960 		break;
961 	case 'N':
962 		separator = 0;
963 		break;
964 	default:
965 		separator = ' ';
966 		break;
967 	}
968 
969 	if (spec.field_width > 0)
970 		len = min_t(int, spec.field_width, 64);
971 
972 	for (i = 0; i < len; ++i) {
973 		if (buf < end)
974 			*buf = hex_asc_hi(addr[i]);
975 		++buf;
976 		if (buf < end)
977 			*buf = hex_asc_lo(addr[i]);
978 		++buf;
979 
980 		if (separator && i != len - 1) {
981 			if (buf < end)
982 				*buf = separator;
983 			++buf;
984 		}
985 	}
986 
987 	return buf;
988 }
989 
990 static noinline_for_stack
991 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
992 		    struct printf_spec spec, const char *fmt)
993 {
994 	const int CHUNKSZ = 32;
995 	int nr_bits = max_t(int, spec.field_width, 0);
996 	int i, chunksz;
997 	bool first = true;
998 
999 	/* reused to print numbers */
1000 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1001 
1002 	chunksz = nr_bits & (CHUNKSZ - 1);
1003 	if (chunksz == 0)
1004 		chunksz = CHUNKSZ;
1005 
1006 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1007 	for (; i >= 0; i -= CHUNKSZ) {
1008 		u32 chunkmask, val;
1009 		int word, bit;
1010 
1011 		chunkmask = ((1ULL << chunksz) - 1);
1012 		word = i / BITS_PER_LONG;
1013 		bit = i % BITS_PER_LONG;
1014 		val = (bitmap[word] >> bit) & chunkmask;
1015 
1016 		if (!first) {
1017 			if (buf < end)
1018 				*buf = ',';
1019 			buf++;
1020 		}
1021 		first = false;
1022 
1023 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1024 		buf = number(buf, end, val, spec);
1025 
1026 		chunksz = CHUNKSZ;
1027 	}
1028 	return buf;
1029 }
1030 
1031 static noinline_for_stack
1032 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1033 			 struct printf_spec spec, const char *fmt)
1034 {
1035 	int nr_bits = max_t(int, spec.field_width, 0);
1036 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
1037 	int cur, rbot, rtop;
1038 	bool first = true;
1039 
1040 	rbot = cur = find_first_bit(bitmap, nr_bits);
1041 	while (cur < nr_bits) {
1042 		rtop = cur;
1043 		cur = find_next_bit(bitmap, nr_bits, cur + 1);
1044 		if (cur < nr_bits && cur <= rtop + 1)
1045 			continue;
1046 
1047 		if (!first) {
1048 			if (buf < end)
1049 				*buf = ',';
1050 			buf++;
1051 		}
1052 		first = false;
1053 
1054 		buf = number(buf, end, rbot, default_dec_spec);
1055 		if (rbot < rtop) {
1056 			if (buf < end)
1057 				*buf = '-';
1058 			buf++;
1059 
1060 			buf = number(buf, end, rtop, default_dec_spec);
1061 		}
1062 
1063 		rbot = cur;
1064 	}
1065 	return buf;
1066 }
1067 
1068 static noinline_for_stack
1069 char *mac_address_string(char *buf, char *end, u8 *addr,
1070 			 struct printf_spec spec, const char *fmt)
1071 {
1072 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1073 	char *p = mac_addr;
1074 	int i;
1075 	char separator;
1076 	bool reversed = false;
1077 
1078 	switch (fmt[1]) {
1079 	case 'F':
1080 		separator = '-';
1081 		break;
1082 
1083 	case 'R':
1084 		reversed = true;
1085 		/* fall through */
1086 
1087 	default:
1088 		separator = ':';
1089 		break;
1090 	}
1091 
1092 	for (i = 0; i < 6; i++) {
1093 		if (reversed)
1094 			p = hex_byte_pack(p, addr[5 - i]);
1095 		else
1096 			p = hex_byte_pack(p, addr[i]);
1097 
1098 		if (fmt[0] == 'M' && i != 5)
1099 			*p++ = separator;
1100 	}
1101 	*p = '\0';
1102 
1103 	return string(buf, end, mac_addr, spec);
1104 }
1105 
1106 static noinline_for_stack
1107 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1108 {
1109 	int i;
1110 	bool leading_zeros = (fmt[0] == 'i');
1111 	int index;
1112 	int step;
1113 
1114 	switch (fmt[2]) {
1115 	case 'h':
1116 #ifdef __BIG_ENDIAN
1117 		index = 0;
1118 		step = 1;
1119 #else
1120 		index = 3;
1121 		step = -1;
1122 #endif
1123 		break;
1124 	case 'l':
1125 		index = 3;
1126 		step = -1;
1127 		break;
1128 	case 'n':
1129 	case 'b':
1130 	default:
1131 		index = 0;
1132 		step = 1;
1133 		break;
1134 	}
1135 	for (i = 0; i < 4; i++) {
1136 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1137 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1138 		if (leading_zeros) {
1139 			if (digits < 3)
1140 				*p++ = '0';
1141 			if (digits < 2)
1142 				*p++ = '0';
1143 		}
1144 		/* reverse the digits in the quad */
1145 		while (digits--)
1146 			*p++ = temp[digits];
1147 		if (i < 3)
1148 			*p++ = '.';
1149 		index += step;
1150 	}
1151 	*p = '\0';
1152 
1153 	return p;
1154 }
1155 
1156 static noinline_for_stack
1157 char *ip6_compressed_string(char *p, const char *addr)
1158 {
1159 	int i, j, range;
1160 	unsigned char zerolength[8];
1161 	int longest = 1;
1162 	int colonpos = -1;
1163 	u16 word;
1164 	u8 hi, lo;
1165 	bool needcolon = false;
1166 	bool useIPv4;
1167 	struct in6_addr in6;
1168 
1169 	memcpy(&in6, addr, sizeof(struct in6_addr));
1170 
1171 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1172 
1173 	memset(zerolength, 0, sizeof(zerolength));
1174 
1175 	if (useIPv4)
1176 		range = 6;
1177 	else
1178 		range = 8;
1179 
1180 	/* find position of longest 0 run */
1181 	for (i = 0; i < range; i++) {
1182 		for (j = i; j < range; j++) {
1183 			if (in6.s6_addr16[j] != 0)
1184 				break;
1185 			zerolength[i]++;
1186 		}
1187 	}
1188 	for (i = 0; i < range; i++) {
1189 		if (zerolength[i] > longest) {
1190 			longest = zerolength[i];
1191 			colonpos = i;
1192 		}
1193 	}
1194 	if (longest == 1)		/* don't compress a single 0 */
1195 		colonpos = -1;
1196 
1197 	/* emit address */
1198 	for (i = 0; i < range; i++) {
1199 		if (i == colonpos) {
1200 			if (needcolon || i == 0)
1201 				*p++ = ':';
1202 			*p++ = ':';
1203 			needcolon = false;
1204 			i += longest - 1;
1205 			continue;
1206 		}
1207 		if (needcolon) {
1208 			*p++ = ':';
1209 			needcolon = false;
1210 		}
1211 		/* hex u16 without leading 0s */
1212 		word = ntohs(in6.s6_addr16[i]);
1213 		hi = word >> 8;
1214 		lo = word & 0xff;
1215 		if (hi) {
1216 			if (hi > 0x0f)
1217 				p = hex_byte_pack(p, hi);
1218 			else
1219 				*p++ = hex_asc_lo(hi);
1220 			p = hex_byte_pack(p, lo);
1221 		}
1222 		else if (lo > 0x0f)
1223 			p = hex_byte_pack(p, lo);
1224 		else
1225 			*p++ = hex_asc_lo(lo);
1226 		needcolon = true;
1227 	}
1228 
1229 	if (useIPv4) {
1230 		if (needcolon)
1231 			*p++ = ':';
1232 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1233 	}
1234 	*p = '\0';
1235 
1236 	return p;
1237 }
1238 
1239 static noinline_for_stack
1240 char *ip6_string(char *p, const char *addr, const char *fmt)
1241 {
1242 	int i;
1243 
1244 	for (i = 0; i < 8; i++) {
1245 		p = hex_byte_pack(p, *addr++);
1246 		p = hex_byte_pack(p, *addr++);
1247 		if (fmt[0] == 'I' && i != 7)
1248 			*p++ = ':';
1249 	}
1250 	*p = '\0';
1251 
1252 	return p;
1253 }
1254 
1255 static noinline_for_stack
1256 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1257 		      struct printf_spec spec, const char *fmt)
1258 {
1259 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1260 
1261 	if (fmt[0] == 'I' && fmt[2] == 'c')
1262 		ip6_compressed_string(ip6_addr, addr);
1263 	else
1264 		ip6_string(ip6_addr, addr, fmt);
1265 
1266 	return string(buf, end, ip6_addr, spec);
1267 }
1268 
1269 static noinline_for_stack
1270 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1271 		      struct printf_spec spec, const char *fmt)
1272 {
1273 	char ip4_addr[sizeof("255.255.255.255")];
1274 
1275 	ip4_string(ip4_addr, addr, fmt);
1276 
1277 	return string(buf, end, ip4_addr, spec);
1278 }
1279 
1280 static noinline_for_stack
1281 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1282 			 struct printf_spec spec, const char *fmt)
1283 {
1284 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1285 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1286 		      sizeof(":12345") + sizeof("/123456789") +
1287 		      sizeof("%1234567890")];
1288 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1289 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1290 	char fmt6[2] = { fmt[0], '6' };
1291 	u8 off = 0;
1292 
1293 	fmt++;
1294 	while (isalpha(*++fmt)) {
1295 		switch (*fmt) {
1296 		case 'p':
1297 			have_p = true;
1298 			break;
1299 		case 'f':
1300 			have_f = true;
1301 			break;
1302 		case 's':
1303 			have_s = true;
1304 			break;
1305 		case 'c':
1306 			have_c = true;
1307 			break;
1308 		}
1309 	}
1310 
1311 	if (have_p || have_s || have_f) {
1312 		*p = '[';
1313 		off = 1;
1314 	}
1315 
1316 	if (fmt6[0] == 'I' && have_c)
1317 		p = ip6_compressed_string(ip6_addr + off, addr);
1318 	else
1319 		p = ip6_string(ip6_addr + off, addr, fmt6);
1320 
1321 	if (have_p || have_s || have_f)
1322 		*p++ = ']';
1323 
1324 	if (have_p) {
1325 		*p++ = ':';
1326 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1327 	}
1328 	if (have_f) {
1329 		*p++ = '/';
1330 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1331 					  IPV6_FLOWINFO_MASK), spec);
1332 	}
1333 	if (have_s) {
1334 		*p++ = '%';
1335 		p = number(p, pend, sa->sin6_scope_id, spec);
1336 	}
1337 	*p = '\0';
1338 
1339 	return string(buf, end, ip6_addr, spec);
1340 }
1341 
1342 static noinline_for_stack
1343 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1344 			 struct printf_spec spec, const char *fmt)
1345 {
1346 	bool have_p = false;
1347 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1348 	char *pend = ip4_addr + sizeof(ip4_addr);
1349 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1350 	char fmt4[3] = { fmt[0], '4', 0 };
1351 
1352 	fmt++;
1353 	while (isalpha(*++fmt)) {
1354 		switch (*fmt) {
1355 		case 'p':
1356 			have_p = true;
1357 			break;
1358 		case 'h':
1359 		case 'l':
1360 		case 'n':
1361 		case 'b':
1362 			fmt4[2] = *fmt;
1363 			break;
1364 		}
1365 	}
1366 
1367 	p = ip4_string(ip4_addr, addr, fmt4);
1368 	if (have_p) {
1369 		*p++ = ':';
1370 		p = number(p, pend, ntohs(sa->sin_port), spec);
1371 	}
1372 	*p = '\0';
1373 
1374 	return string(buf, end, ip4_addr, spec);
1375 }
1376 
1377 static noinline_for_stack
1378 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1379 		     const char *fmt)
1380 {
1381 	bool found = true;
1382 	int count = 1;
1383 	unsigned int flags = 0;
1384 	int len;
1385 
1386 	if (spec.field_width == 0)
1387 		return buf;				/* nothing to print */
1388 
1389 	if (ZERO_OR_NULL_PTR(addr))
1390 		return string(buf, end, NULL, spec);	/* NULL pointer */
1391 
1392 
1393 	do {
1394 		switch (fmt[count++]) {
1395 		case 'a':
1396 			flags |= ESCAPE_ANY;
1397 			break;
1398 		case 'c':
1399 			flags |= ESCAPE_SPECIAL;
1400 			break;
1401 		case 'h':
1402 			flags |= ESCAPE_HEX;
1403 			break;
1404 		case 'n':
1405 			flags |= ESCAPE_NULL;
1406 			break;
1407 		case 'o':
1408 			flags |= ESCAPE_OCTAL;
1409 			break;
1410 		case 'p':
1411 			flags |= ESCAPE_NP;
1412 			break;
1413 		case 's':
1414 			flags |= ESCAPE_SPACE;
1415 			break;
1416 		default:
1417 			found = false;
1418 			break;
1419 		}
1420 	} while (found);
1421 
1422 	if (!flags)
1423 		flags = ESCAPE_ANY_NP;
1424 
1425 	len = spec.field_width < 0 ? 1 : spec.field_width;
1426 
1427 	/*
1428 	 * string_escape_mem() writes as many characters as it can to
1429 	 * the given buffer, and returns the total size of the output
1430 	 * had the buffer been big enough.
1431 	 */
1432 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1433 
1434 	return buf;
1435 }
1436 
1437 static noinline_for_stack
1438 char *uuid_string(char *buf, char *end, const u8 *addr,
1439 		  struct printf_spec spec, const char *fmt)
1440 {
1441 	char uuid[UUID_STRING_LEN + 1];
1442 	char *p = uuid;
1443 	int i;
1444 	const u8 *index = uuid_index;
1445 	bool uc = false;
1446 
1447 	switch (*(++fmt)) {
1448 	case 'L':
1449 		uc = true;		/* fall-through */
1450 	case 'l':
1451 		index = guid_index;
1452 		break;
1453 	case 'B':
1454 		uc = true;
1455 		break;
1456 	}
1457 
1458 	for (i = 0; i < 16; i++) {
1459 		if (uc)
1460 			p = hex_byte_pack_upper(p, addr[index[i]]);
1461 		else
1462 			p = hex_byte_pack(p, addr[index[i]]);
1463 		switch (i) {
1464 		case 3:
1465 		case 5:
1466 		case 7:
1467 		case 9:
1468 			*p++ = '-';
1469 			break;
1470 		}
1471 	}
1472 
1473 	*p = 0;
1474 
1475 	return string(buf, end, uuid, spec);
1476 }
1477 
1478 int kptr_restrict __read_mostly;
1479 
1480 static noinline_for_stack
1481 char *restricted_pointer(char *buf, char *end, const void *ptr,
1482 			 struct printf_spec spec)
1483 {
1484 	switch (kptr_restrict) {
1485 	case 0:
1486 		/* Always print %pK values */
1487 		break;
1488 	case 1: {
1489 		const struct cred *cred;
1490 
1491 		/*
1492 		 * kptr_restrict==1 cannot be used in IRQ context
1493 		 * because its test for CAP_SYSLOG would be meaningless.
1494 		 */
1495 		if (in_irq() || in_serving_softirq() || in_nmi()) {
1496 			if (spec.field_width == -1)
1497 				spec.field_width = 2 * sizeof(ptr);
1498 			return string(buf, end, "pK-error", spec);
1499 		}
1500 
1501 		/*
1502 		 * Only print the real pointer value if the current
1503 		 * process has CAP_SYSLOG and is running with the
1504 		 * same credentials it started with. This is because
1505 		 * access to files is checked at open() time, but %pK
1506 		 * checks permission at read() time. We don't want to
1507 		 * leak pointer values if a binary opens a file using
1508 		 * %pK and then elevates privileges before reading it.
1509 		 */
1510 		cred = current_cred();
1511 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1512 		    !uid_eq(cred->euid, cred->uid) ||
1513 		    !gid_eq(cred->egid, cred->gid))
1514 			ptr = NULL;
1515 		break;
1516 	}
1517 	case 2:
1518 	default:
1519 		/* Always print 0's for %pK */
1520 		ptr = NULL;
1521 		break;
1522 	}
1523 
1524 	return pointer_string(buf, end, ptr, spec);
1525 }
1526 
1527 static noinline_for_stack
1528 char *netdev_bits(char *buf, char *end, const void *addr,
1529 		  struct printf_spec spec,  const char *fmt)
1530 {
1531 	unsigned long long num;
1532 	int size;
1533 
1534 	switch (fmt[1]) {
1535 	case 'F':
1536 		num = *(const netdev_features_t *)addr;
1537 		size = sizeof(netdev_features_t);
1538 		break;
1539 	default:
1540 		return ptr_to_id(buf, end, addr, spec);
1541 	}
1542 
1543 	return special_hex_number(buf, end, num, size);
1544 }
1545 
1546 static noinline_for_stack
1547 char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1548 {
1549 	unsigned long long num;
1550 	int size;
1551 
1552 	switch (fmt[1]) {
1553 	case 'd':
1554 		num = *(const dma_addr_t *)addr;
1555 		size = sizeof(dma_addr_t);
1556 		break;
1557 	case 'p':
1558 	default:
1559 		num = *(const phys_addr_t *)addr;
1560 		size = sizeof(phys_addr_t);
1561 		break;
1562 	}
1563 
1564 	return special_hex_number(buf, end, num, size);
1565 }
1566 
1567 static noinline_for_stack
1568 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1569 {
1570 	int year = tm->tm_year + (r ? 0 : 1900);
1571 	int mon = tm->tm_mon + (r ? 0 : 1);
1572 
1573 	buf = number(buf, end, year, default_dec04_spec);
1574 	if (buf < end)
1575 		*buf = '-';
1576 	buf++;
1577 
1578 	buf = number(buf, end, mon, default_dec02_spec);
1579 	if (buf < end)
1580 		*buf = '-';
1581 	buf++;
1582 
1583 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1584 }
1585 
1586 static noinline_for_stack
1587 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1588 {
1589 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1590 	if (buf < end)
1591 		*buf = ':';
1592 	buf++;
1593 
1594 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1595 	if (buf < end)
1596 		*buf = ':';
1597 	buf++;
1598 
1599 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1600 }
1601 
1602 static noinline_for_stack
1603 char *rtc_str(char *buf, char *end, const struct rtc_time *tm, const char *fmt)
1604 {
1605 	bool have_t = true, have_d = true;
1606 	bool raw = false;
1607 	int count = 2;
1608 
1609 	switch (fmt[count]) {
1610 	case 'd':
1611 		have_t = false;
1612 		count++;
1613 		break;
1614 	case 't':
1615 		have_d = false;
1616 		count++;
1617 		break;
1618 	}
1619 
1620 	raw = fmt[count] == 'r';
1621 
1622 	if (have_d)
1623 		buf = date_str(buf, end, tm, raw);
1624 	if (have_d && have_t) {
1625 		/* Respect ISO 8601 */
1626 		if (buf < end)
1627 			*buf = 'T';
1628 		buf++;
1629 	}
1630 	if (have_t)
1631 		buf = time_str(buf, end, tm, raw);
1632 
1633 	return buf;
1634 }
1635 
1636 static noinline_for_stack
1637 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1638 		    const char *fmt)
1639 {
1640 	switch (fmt[1]) {
1641 	case 'R':
1642 		return rtc_str(buf, end, (const struct rtc_time *)ptr, fmt);
1643 	default:
1644 		return ptr_to_id(buf, end, ptr, spec);
1645 	}
1646 }
1647 
1648 static noinline_for_stack
1649 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1650 	    const char *fmt)
1651 {
1652 	if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1653 		return string(buf, end, NULL, spec);
1654 
1655 	switch (fmt[1]) {
1656 	case 'n':
1657 	default:
1658 #ifdef CONFIG_COMMON_CLK
1659 		return string(buf, end, __clk_get_name(clk), spec);
1660 #else
1661 		return ptr_to_id(buf, end, clk, spec);
1662 #endif
1663 	}
1664 }
1665 
1666 static
1667 char *format_flags(char *buf, char *end, unsigned long flags,
1668 					const struct trace_print_flags *names)
1669 {
1670 	unsigned long mask;
1671 
1672 	for ( ; flags && names->name; names++) {
1673 		mask = names->mask;
1674 		if ((flags & mask) != mask)
1675 			continue;
1676 
1677 		buf = string(buf, end, names->name, default_str_spec);
1678 
1679 		flags &= ~mask;
1680 		if (flags) {
1681 			if (buf < end)
1682 				*buf = '|';
1683 			buf++;
1684 		}
1685 	}
1686 
1687 	if (flags)
1688 		buf = number(buf, end, flags, default_flag_spec);
1689 
1690 	return buf;
1691 }
1692 
1693 static noinline_for_stack
1694 char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1695 {
1696 	unsigned long flags;
1697 	const struct trace_print_flags *names;
1698 
1699 	switch (fmt[1]) {
1700 	case 'p':
1701 		flags = *(unsigned long *)flags_ptr;
1702 		/* Remove zone id */
1703 		flags &= (1UL << NR_PAGEFLAGS) - 1;
1704 		names = pageflag_names;
1705 		break;
1706 	case 'v':
1707 		flags = *(unsigned long *)flags_ptr;
1708 		names = vmaflag_names;
1709 		break;
1710 	case 'g':
1711 		flags = *(gfp_t *)flags_ptr;
1712 		names = gfpflag_names;
1713 		break;
1714 	default:
1715 		WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1716 		return buf;
1717 	}
1718 
1719 	return format_flags(buf, end, flags, names);
1720 }
1721 
1722 static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1723 {
1724 	for ( ; np && depth; depth--)
1725 		np = np->parent;
1726 
1727 	return kbasename(np->full_name);
1728 }
1729 
1730 static noinline_for_stack
1731 char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1732 {
1733 	int depth;
1734 	const struct device_node *parent = np->parent;
1735 
1736 	/* special case for root node */
1737 	if (!parent)
1738 		return string(buf, end, "/", default_str_spec);
1739 
1740 	for (depth = 0; parent->parent; depth++)
1741 		parent = parent->parent;
1742 
1743 	for ( ; depth >= 0; depth--) {
1744 		buf = string(buf, end, "/", default_str_spec);
1745 		buf = string(buf, end, device_node_name_for_depth(np, depth),
1746 			     default_str_spec);
1747 	}
1748 	return buf;
1749 }
1750 
1751 static noinline_for_stack
1752 char *device_node_string(char *buf, char *end, struct device_node *dn,
1753 			 struct printf_spec spec, const char *fmt)
1754 {
1755 	char tbuf[sizeof("xxxx") + 1];
1756 	const char *p;
1757 	int ret;
1758 	char *buf_start = buf;
1759 	struct property *prop;
1760 	bool has_mult, pass;
1761 	static const struct printf_spec num_spec = {
1762 		.flags = SMALL,
1763 		.field_width = -1,
1764 		.precision = -1,
1765 		.base = 10,
1766 	};
1767 
1768 	struct printf_spec str_spec = spec;
1769 	str_spec.field_width = -1;
1770 
1771 	if (!IS_ENABLED(CONFIG_OF))
1772 		return string(buf, end, "(!OF)", spec);
1773 
1774 	if ((unsigned long)dn < PAGE_SIZE)
1775 		return string(buf, end, "(null)", spec);
1776 
1777 	/* simple case without anything any more format specifiers */
1778 	fmt++;
1779 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1780 		fmt = "f";
1781 
1782 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1783 		int precision;
1784 		if (pass) {
1785 			if (buf < end)
1786 				*buf = ':';
1787 			buf++;
1788 		}
1789 
1790 		switch (*fmt) {
1791 		case 'f':	/* full_name */
1792 			buf = device_node_gen_full_name(dn, buf, end);
1793 			break;
1794 		case 'n':	/* name */
1795 			p = kbasename(of_node_full_name(dn));
1796 			precision = str_spec.precision;
1797 			str_spec.precision = strchrnul(p, '@') - p;
1798 			buf = string(buf, end, p, str_spec);
1799 			str_spec.precision = precision;
1800 			break;
1801 		case 'p':	/* phandle */
1802 			buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1803 			break;
1804 		case 'P':	/* path-spec */
1805 			p = kbasename(of_node_full_name(dn));
1806 			if (!p[1])
1807 				p = "/";
1808 			buf = string(buf, end, p, str_spec);
1809 			break;
1810 		case 'F':	/* flags */
1811 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1812 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1813 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1814 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1815 			tbuf[4] = 0;
1816 			buf = string(buf, end, tbuf, str_spec);
1817 			break;
1818 		case 'c':	/* major compatible string */
1819 			ret = of_property_read_string(dn, "compatible", &p);
1820 			if (!ret)
1821 				buf = string(buf, end, p, str_spec);
1822 			break;
1823 		case 'C':	/* full compatible string */
1824 			has_mult = false;
1825 			of_property_for_each_string(dn, "compatible", prop, p) {
1826 				if (has_mult)
1827 					buf = string(buf, end, ",", str_spec);
1828 				buf = string(buf, end, "\"", str_spec);
1829 				buf = string(buf, end, p, str_spec);
1830 				buf = string(buf, end, "\"", str_spec);
1831 
1832 				has_mult = true;
1833 			}
1834 			break;
1835 		default:
1836 			break;
1837 		}
1838 	}
1839 
1840 	return widen_string(buf, buf - buf_start, end, spec);
1841 }
1842 
1843 /*
1844  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1845  * by an extra set of alphanumeric characters that are extended format
1846  * specifiers.
1847  *
1848  * Please update scripts/checkpatch.pl when adding/removing conversion
1849  * characters.  (Search for "check for vsprintf extension").
1850  *
1851  * Right now we handle:
1852  *
1853  * - 'S' For symbolic direct pointers (or function descriptors) with offset
1854  * - 's' For symbolic direct pointers (or function descriptors) without offset
1855  * - 'F' Same as 'S'
1856  * - 'f' Same as 's'
1857  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1858  * - 'B' For backtraced symbolic direct pointers with offset
1859  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1860  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1861  * - 'b[l]' For a bitmap, the number of bits is determined by the field
1862  *       width which must be explicitly specified either as part of the
1863  *       format string '%32b[l]' or through '%*b[l]', [l] selects
1864  *       range-list format instead of hex format
1865  * - 'M' For a 6-byte MAC address, it prints the address in the
1866  *       usual colon-separated hex notation
1867  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1868  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1869  *       with a dash-separated hex notation
1870  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1871  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1872  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1873  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1874  *       [S][pfs]
1875  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1876  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1877  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1878  *       IPv6 omits the colons (01020304...0f)
1879  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1880  *       [S][pfs]
1881  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1882  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1883  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1884  * - 'I[6S]c' for IPv6 addresses printed as specified by
1885  *       http://tools.ietf.org/html/rfc5952
1886  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1887  *                of the following flags (see string_escape_mem() for the
1888  *                details):
1889  *                  a - ESCAPE_ANY
1890  *                  c - ESCAPE_SPECIAL
1891  *                  h - ESCAPE_HEX
1892  *                  n - ESCAPE_NULL
1893  *                  o - ESCAPE_OCTAL
1894  *                  p - ESCAPE_NP
1895  *                  s - ESCAPE_SPACE
1896  *                By default ESCAPE_ANY_NP is used.
1897  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1898  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1899  *       Options for %pU are:
1900  *         b big endian lower case hex (default)
1901  *         B big endian UPPER case hex
1902  *         l little endian lower case hex
1903  *         L little endian UPPER case hex
1904  *           big endian output byte order is:
1905  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1906  *           little endian output byte order is:
1907  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1908  * - 'V' For a struct va_format which contains a format string * and va_list *,
1909  *       call vsnprintf(->format, *->va_list).
1910  *       Implements a "recursive vsnprintf".
1911  *       Do not use this feature without some mechanism to verify the
1912  *       correctness of the format string and va_list arguments.
1913  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1914  * - 'NF' For a netdev_features_t
1915  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1916  *            a certain separator (' ' by default):
1917  *              C colon
1918  *              D dash
1919  *              N no separator
1920  *            The maximum supported length is 64 bytes of the input. Consider
1921  *            to use print_hex_dump() for the larger input.
1922  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1923  *           (default assumed to be phys_addr_t, passed by reference)
1924  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1925  * - 'D[234]' Same as 'd' but for a struct file
1926  * - 'g' For block_device name (gendisk + partition number)
1927  * - 't[R][dt][r]' For time and date as represented:
1928  *      R    struct rtc_time
1929  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1930  *       (legacy clock framework) of the clock
1931  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1932  *        (legacy clock framework) of the clock
1933  * - 'Cr' For a clock, it prints the current rate of the clock
1934  * - 'G' For flags to be printed as a collection of symbolic strings that would
1935  *       construct the specific value. Supported flags given by option:
1936  *       p page flags (see struct page) given as pointer to unsigned long
1937  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1938  *       v vma flags (VM_*) given as pointer to unsigned long
1939  * - 'OF[fnpPcCF]'  For a device tree object
1940  *                  Without any optional arguments prints the full_name
1941  *                  f device node full_name
1942  *                  n device node name
1943  *                  p device node phandle
1944  *                  P device node path spec (name + @unit)
1945  *                  F device node flags
1946  *                  c major compatible string
1947  *                  C full compatible string
1948  * - 'x' For printing the address. Equivalent to "%lx".
1949  *
1950  * ** When making changes please also update:
1951  *	Documentation/core-api/printk-formats.rst
1952  *
1953  * Note: The default behaviour (unadorned %p) is to hash the address,
1954  * rendering it useful as a unique identifier.
1955  */
1956 static noinline_for_stack
1957 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1958 	      struct printf_spec spec)
1959 {
1960 	const int default_width = 2 * sizeof(void *);
1961 
1962 	if (!ptr && *fmt != 'K' && *fmt != 'x') {
1963 		/*
1964 		 * Print (null) with the same width as a pointer so it makes
1965 		 * tabular output look nice.
1966 		 */
1967 		if (spec.field_width == -1)
1968 			spec.field_width = default_width;
1969 		return string(buf, end, "(null)", spec);
1970 	}
1971 
1972 	switch (*fmt) {
1973 	case 'F':
1974 	case 'f':
1975 	case 'S':
1976 	case 's':
1977 		ptr = dereference_symbol_descriptor(ptr);
1978 		/* Fallthrough */
1979 	case 'B':
1980 		return symbol_string(buf, end, ptr, spec, fmt);
1981 	case 'R':
1982 	case 'r':
1983 		return resource_string(buf, end, ptr, spec, fmt);
1984 	case 'h':
1985 		return hex_string(buf, end, ptr, spec, fmt);
1986 	case 'b':
1987 		switch (fmt[1]) {
1988 		case 'l':
1989 			return bitmap_list_string(buf, end, ptr, spec, fmt);
1990 		default:
1991 			return bitmap_string(buf, end, ptr, spec, fmt);
1992 		}
1993 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
1994 	case 'm':			/* Contiguous: 000102030405 */
1995 					/* [mM]F (FDDI) */
1996 					/* [mM]R (Reverse order; Bluetooth) */
1997 		return mac_address_string(buf, end, ptr, spec, fmt);
1998 	case 'I':			/* Formatted IP supported
1999 					 * 4:	1.2.3.4
2000 					 * 6:	0001:0203:...:0708
2001 					 * 6c:	1::708 or 1::1.2.3.4
2002 					 */
2003 	case 'i':			/* Contiguous:
2004 					 * 4:	001.002.003.004
2005 					 * 6:   000102...0f
2006 					 */
2007 		switch (fmt[1]) {
2008 		case '6':
2009 			return ip6_addr_string(buf, end, ptr, spec, fmt);
2010 		case '4':
2011 			return ip4_addr_string(buf, end, ptr, spec, fmt);
2012 		case 'S': {
2013 			const union {
2014 				struct sockaddr		raw;
2015 				struct sockaddr_in	v4;
2016 				struct sockaddr_in6	v6;
2017 			} *sa = ptr;
2018 
2019 			switch (sa->raw.sa_family) {
2020 			case AF_INET:
2021 				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
2022 			case AF_INET6:
2023 				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
2024 			default:
2025 				return string(buf, end, "(invalid address)", spec);
2026 			}}
2027 		}
2028 		break;
2029 	case 'E':
2030 		return escaped_string(buf, end, ptr, spec, fmt);
2031 	case 'U':
2032 		return uuid_string(buf, end, ptr, spec, fmt);
2033 	case 'V':
2034 		{
2035 			va_list va;
2036 
2037 			va_copy(va, *((struct va_format *)ptr)->va);
2038 			buf += vsnprintf(buf, end > buf ? end - buf : 0,
2039 					 ((struct va_format *)ptr)->fmt, va);
2040 			va_end(va);
2041 			return buf;
2042 		}
2043 	case 'K':
2044 		if (!kptr_restrict)
2045 			break;
2046 		return restricted_pointer(buf, end, ptr, spec);
2047 	case 'N':
2048 		return netdev_bits(buf, end, ptr, spec, fmt);
2049 	case 'a':
2050 		return address_val(buf, end, ptr, fmt);
2051 	case 'd':
2052 		return dentry_name(buf, end, ptr, spec, fmt);
2053 	case 't':
2054 		return time_and_date(buf, end, ptr, spec, fmt);
2055 	case 'C':
2056 		return clock(buf, end, ptr, spec, fmt);
2057 	case 'D':
2058 		return dentry_name(buf, end,
2059 				   ((const struct file *)ptr)->f_path.dentry,
2060 				   spec, fmt);
2061 #ifdef CONFIG_BLOCK
2062 	case 'g':
2063 		return bdev_name(buf, end, ptr, spec, fmt);
2064 #endif
2065 
2066 	case 'G':
2067 		return flags_string(buf, end, ptr, fmt);
2068 	case 'O':
2069 		switch (fmt[1]) {
2070 		case 'F':
2071 			return device_node_string(buf, end, ptr, spec, fmt + 1);
2072 		}
2073 		break;
2074 	case 'x':
2075 		return pointer_string(buf, end, ptr, spec);
2076 	}
2077 
2078 	/* default is to _not_ leak addresses, hash before printing */
2079 	return ptr_to_id(buf, end, ptr, spec);
2080 }
2081 
2082 /*
2083  * Helper function to decode printf style format.
2084  * Each call decode a token from the format and return the
2085  * number of characters read (or likely the delta where it wants
2086  * to go on the next call).
2087  * The decoded token is returned through the parameters
2088  *
2089  * 'h', 'l', or 'L' for integer fields
2090  * 'z' support added 23/7/1999 S.H.
2091  * 'z' changed to 'Z' --davidm 1/25/99
2092  * 'Z' changed to 'z' --adobriyan 2017-01-25
2093  * 't' added for ptrdiff_t
2094  *
2095  * @fmt: the format string
2096  * @type of the token returned
2097  * @flags: various flags such as +, -, # tokens..
2098  * @field_width: overwritten width
2099  * @base: base of the number (octal, hex, ...)
2100  * @precision: precision of a number
2101  * @qualifier: qualifier of a number (long, size_t, ...)
2102  */
2103 static noinline_for_stack
2104 int format_decode(const char *fmt, struct printf_spec *spec)
2105 {
2106 	const char *start = fmt;
2107 	char qualifier;
2108 
2109 	/* we finished early by reading the field width */
2110 	if (spec->type == FORMAT_TYPE_WIDTH) {
2111 		if (spec->field_width < 0) {
2112 			spec->field_width = -spec->field_width;
2113 			spec->flags |= LEFT;
2114 		}
2115 		spec->type = FORMAT_TYPE_NONE;
2116 		goto precision;
2117 	}
2118 
2119 	/* we finished early by reading the precision */
2120 	if (spec->type == FORMAT_TYPE_PRECISION) {
2121 		if (spec->precision < 0)
2122 			spec->precision = 0;
2123 
2124 		spec->type = FORMAT_TYPE_NONE;
2125 		goto qualifier;
2126 	}
2127 
2128 	/* By default */
2129 	spec->type = FORMAT_TYPE_NONE;
2130 
2131 	for (; *fmt ; ++fmt) {
2132 		if (*fmt == '%')
2133 			break;
2134 	}
2135 
2136 	/* Return the current non-format string */
2137 	if (fmt != start || !*fmt)
2138 		return fmt - start;
2139 
2140 	/* Process flags */
2141 	spec->flags = 0;
2142 
2143 	while (1) { /* this also skips first '%' */
2144 		bool found = true;
2145 
2146 		++fmt;
2147 
2148 		switch (*fmt) {
2149 		case '-': spec->flags |= LEFT;    break;
2150 		case '+': spec->flags |= PLUS;    break;
2151 		case ' ': spec->flags |= SPACE;   break;
2152 		case '#': spec->flags |= SPECIAL; break;
2153 		case '0': spec->flags |= ZEROPAD; break;
2154 		default:  found = false;
2155 		}
2156 
2157 		if (!found)
2158 			break;
2159 	}
2160 
2161 	/* get field width */
2162 	spec->field_width = -1;
2163 
2164 	if (isdigit(*fmt))
2165 		spec->field_width = skip_atoi(&fmt);
2166 	else if (*fmt == '*') {
2167 		/* it's the next argument */
2168 		spec->type = FORMAT_TYPE_WIDTH;
2169 		return ++fmt - start;
2170 	}
2171 
2172 precision:
2173 	/* get the precision */
2174 	spec->precision = -1;
2175 	if (*fmt == '.') {
2176 		++fmt;
2177 		if (isdigit(*fmt)) {
2178 			spec->precision = skip_atoi(&fmt);
2179 			if (spec->precision < 0)
2180 				spec->precision = 0;
2181 		} else if (*fmt == '*') {
2182 			/* it's the next argument */
2183 			spec->type = FORMAT_TYPE_PRECISION;
2184 			return ++fmt - start;
2185 		}
2186 	}
2187 
2188 qualifier:
2189 	/* get the conversion qualifier */
2190 	qualifier = 0;
2191 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2192 	    *fmt == 'z' || *fmt == 't') {
2193 		qualifier = *fmt++;
2194 		if (unlikely(qualifier == *fmt)) {
2195 			if (qualifier == 'l') {
2196 				qualifier = 'L';
2197 				++fmt;
2198 			} else if (qualifier == 'h') {
2199 				qualifier = 'H';
2200 				++fmt;
2201 			}
2202 		}
2203 	}
2204 
2205 	/* default base */
2206 	spec->base = 10;
2207 	switch (*fmt) {
2208 	case 'c':
2209 		spec->type = FORMAT_TYPE_CHAR;
2210 		return ++fmt - start;
2211 
2212 	case 's':
2213 		spec->type = FORMAT_TYPE_STR;
2214 		return ++fmt - start;
2215 
2216 	case 'p':
2217 		spec->type = FORMAT_TYPE_PTR;
2218 		return ++fmt - start;
2219 
2220 	case '%':
2221 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2222 		return ++fmt - start;
2223 
2224 	/* integer number formats - set up the flags and "break" */
2225 	case 'o':
2226 		spec->base = 8;
2227 		break;
2228 
2229 	case 'x':
2230 		spec->flags |= SMALL;
2231 		/* fall through */
2232 
2233 	case 'X':
2234 		spec->base = 16;
2235 		break;
2236 
2237 	case 'd':
2238 	case 'i':
2239 		spec->flags |= SIGN;
2240 	case 'u':
2241 		break;
2242 
2243 	case 'n':
2244 		/*
2245 		 * Since %n poses a greater security risk than
2246 		 * utility, treat it as any other invalid or
2247 		 * unsupported format specifier.
2248 		 */
2249 		/* Fall-through */
2250 
2251 	default:
2252 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2253 		spec->type = FORMAT_TYPE_INVALID;
2254 		return fmt - start;
2255 	}
2256 
2257 	if (qualifier == 'L')
2258 		spec->type = FORMAT_TYPE_LONG_LONG;
2259 	else if (qualifier == 'l') {
2260 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2261 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2262 	} else if (qualifier == 'z') {
2263 		spec->type = FORMAT_TYPE_SIZE_T;
2264 	} else if (qualifier == 't') {
2265 		spec->type = FORMAT_TYPE_PTRDIFF;
2266 	} else if (qualifier == 'H') {
2267 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2268 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2269 	} else if (qualifier == 'h') {
2270 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2271 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2272 	} else {
2273 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2274 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2275 	}
2276 
2277 	return ++fmt - start;
2278 }
2279 
2280 static void
2281 set_field_width(struct printf_spec *spec, int width)
2282 {
2283 	spec->field_width = width;
2284 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2285 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2286 	}
2287 }
2288 
2289 static void
2290 set_precision(struct printf_spec *spec, int prec)
2291 {
2292 	spec->precision = prec;
2293 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2294 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2295 	}
2296 }
2297 
2298 /**
2299  * vsnprintf - Format a string and place it in a buffer
2300  * @buf: The buffer to place the result into
2301  * @size: The size of the buffer, including the trailing null space
2302  * @fmt: The format string to use
2303  * @args: Arguments for the format string
2304  *
2305  * This function generally follows C99 vsnprintf, but has some
2306  * extensions and a few limitations:
2307  *
2308  *  - ``%n`` is unsupported
2309  *  - ``%p*`` is handled by pointer()
2310  *
2311  * See pointer() or Documentation/core-api/printk-formats.rst for more
2312  * extensive description.
2313  *
2314  * **Please update the documentation in both places when making changes**
2315  *
2316  * The return value is the number of characters which would
2317  * be generated for the given input, excluding the trailing
2318  * '\0', as per ISO C99. If you want to have the exact
2319  * number of characters written into @buf as return value
2320  * (not including the trailing '\0'), use vscnprintf(). If the
2321  * return is greater than or equal to @size, the resulting
2322  * string is truncated.
2323  *
2324  * If you're not already dealing with a va_list consider using snprintf().
2325  */
2326 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2327 {
2328 	unsigned long long num;
2329 	char *str, *end;
2330 	struct printf_spec spec = {0};
2331 
2332 	/* Reject out-of-range values early.  Large positive sizes are
2333 	   used for unknown buffer sizes. */
2334 	if (WARN_ON_ONCE(size > INT_MAX))
2335 		return 0;
2336 
2337 	str = buf;
2338 	end = buf + size;
2339 
2340 	/* Make sure end is always >= buf */
2341 	if (end < buf) {
2342 		end = ((void *)-1);
2343 		size = end - buf;
2344 	}
2345 
2346 	while (*fmt) {
2347 		const char *old_fmt = fmt;
2348 		int read = format_decode(fmt, &spec);
2349 
2350 		fmt += read;
2351 
2352 		switch (spec.type) {
2353 		case FORMAT_TYPE_NONE: {
2354 			int copy = read;
2355 			if (str < end) {
2356 				if (copy > end - str)
2357 					copy = end - str;
2358 				memcpy(str, old_fmt, copy);
2359 			}
2360 			str += read;
2361 			break;
2362 		}
2363 
2364 		case FORMAT_TYPE_WIDTH:
2365 			set_field_width(&spec, va_arg(args, int));
2366 			break;
2367 
2368 		case FORMAT_TYPE_PRECISION:
2369 			set_precision(&spec, va_arg(args, int));
2370 			break;
2371 
2372 		case FORMAT_TYPE_CHAR: {
2373 			char c;
2374 
2375 			if (!(spec.flags & LEFT)) {
2376 				while (--spec.field_width > 0) {
2377 					if (str < end)
2378 						*str = ' ';
2379 					++str;
2380 
2381 				}
2382 			}
2383 			c = (unsigned char) va_arg(args, int);
2384 			if (str < end)
2385 				*str = c;
2386 			++str;
2387 			while (--spec.field_width > 0) {
2388 				if (str < end)
2389 					*str = ' ';
2390 				++str;
2391 			}
2392 			break;
2393 		}
2394 
2395 		case FORMAT_TYPE_STR:
2396 			str = string(str, end, va_arg(args, char *), spec);
2397 			break;
2398 
2399 		case FORMAT_TYPE_PTR:
2400 			str = pointer(fmt, str, end, va_arg(args, void *),
2401 				      spec);
2402 			while (isalnum(*fmt))
2403 				fmt++;
2404 			break;
2405 
2406 		case FORMAT_TYPE_PERCENT_CHAR:
2407 			if (str < end)
2408 				*str = '%';
2409 			++str;
2410 			break;
2411 
2412 		case FORMAT_TYPE_INVALID:
2413 			/*
2414 			 * Presumably the arguments passed gcc's type
2415 			 * checking, but there is no safe or sane way
2416 			 * for us to continue parsing the format and
2417 			 * fetching from the va_list; the remaining
2418 			 * specifiers and arguments would be out of
2419 			 * sync.
2420 			 */
2421 			goto out;
2422 
2423 		default:
2424 			switch (spec.type) {
2425 			case FORMAT_TYPE_LONG_LONG:
2426 				num = va_arg(args, long long);
2427 				break;
2428 			case FORMAT_TYPE_ULONG:
2429 				num = va_arg(args, unsigned long);
2430 				break;
2431 			case FORMAT_TYPE_LONG:
2432 				num = va_arg(args, long);
2433 				break;
2434 			case FORMAT_TYPE_SIZE_T:
2435 				if (spec.flags & SIGN)
2436 					num = va_arg(args, ssize_t);
2437 				else
2438 					num = va_arg(args, size_t);
2439 				break;
2440 			case FORMAT_TYPE_PTRDIFF:
2441 				num = va_arg(args, ptrdiff_t);
2442 				break;
2443 			case FORMAT_TYPE_UBYTE:
2444 				num = (unsigned char) va_arg(args, int);
2445 				break;
2446 			case FORMAT_TYPE_BYTE:
2447 				num = (signed char) va_arg(args, int);
2448 				break;
2449 			case FORMAT_TYPE_USHORT:
2450 				num = (unsigned short) va_arg(args, int);
2451 				break;
2452 			case FORMAT_TYPE_SHORT:
2453 				num = (short) va_arg(args, int);
2454 				break;
2455 			case FORMAT_TYPE_INT:
2456 				num = (int) va_arg(args, int);
2457 				break;
2458 			default:
2459 				num = va_arg(args, unsigned int);
2460 			}
2461 
2462 			str = number(str, end, num, spec);
2463 		}
2464 	}
2465 
2466 out:
2467 	if (size > 0) {
2468 		if (str < end)
2469 			*str = '\0';
2470 		else
2471 			end[-1] = '\0';
2472 	}
2473 
2474 	/* the trailing null byte doesn't count towards the total */
2475 	return str-buf;
2476 
2477 }
2478 EXPORT_SYMBOL(vsnprintf);
2479 
2480 /**
2481  * vscnprintf - Format a string and place it in a buffer
2482  * @buf: The buffer to place the result into
2483  * @size: The size of the buffer, including the trailing null space
2484  * @fmt: The format string to use
2485  * @args: Arguments for the format string
2486  *
2487  * The return value is the number of characters which have been written into
2488  * the @buf not including the trailing '\0'. If @size is == 0 the function
2489  * returns 0.
2490  *
2491  * If you're not already dealing with a va_list consider using scnprintf().
2492  *
2493  * See the vsnprintf() documentation for format string extensions over C99.
2494  */
2495 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2496 {
2497 	int i;
2498 
2499 	i = vsnprintf(buf, size, fmt, args);
2500 
2501 	if (likely(i < size))
2502 		return i;
2503 	if (size != 0)
2504 		return size - 1;
2505 	return 0;
2506 }
2507 EXPORT_SYMBOL(vscnprintf);
2508 
2509 /**
2510  * snprintf - Format a string and place it in a buffer
2511  * @buf: The buffer to place the result into
2512  * @size: The size of the buffer, including the trailing null space
2513  * @fmt: The format string to use
2514  * @...: Arguments for the format string
2515  *
2516  * The return value is the number of characters which would be
2517  * generated for the given input, excluding the trailing null,
2518  * as per ISO C99.  If the return is greater than or equal to
2519  * @size, the resulting string is truncated.
2520  *
2521  * See the vsnprintf() documentation for format string extensions over C99.
2522  */
2523 int snprintf(char *buf, size_t size, const char *fmt, ...)
2524 {
2525 	va_list args;
2526 	int i;
2527 
2528 	va_start(args, fmt);
2529 	i = vsnprintf(buf, size, fmt, args);
2530 	va_end(args);
2531 
2532 	return i;
2533 }
2534 EXPORT_SYMBOL(snprintf);
2535 
2536 /**
2537  * scnprintf - Format a string and place it in a buffer
2538  * @buf: The buffer to place the result into
2539  * @size: The size of the buffer, including the trailing null space
2540  * @fmt: The format string to use
2541  * @...: Arguments for the format string
2542  *
2543  * The return value is the number of characters written into @buf not including
2544  * the trailing '\0'. If @size is == 0 the function returns 0.
2545  */
2546 
2547 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2548 {
2549 	va_list args;
2550 	int i;
2551 
2552 	va_start(args, fmt);
2553 	i = vscnprintf(buf, size, fmt, args);
2554 	va_end(args);
2555 
2556 	return i;
2557 }
2558 EXPORT_SYMBOL(scnprintf);
2559 
2560 /**
2561  * vsprintf - Format a string and place it in a buffer
2562  * @buf: The buffer to place the result into
2563  * @fmt: The format string to use
2564  * @args: Arguments for the format string
2565  *
2566  * The function returns the number of characters written
2567  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2568  * buffer overflows.
2569  *
2570  * If you're not already dealing with a va_list consider using sprintf().
2571  *
2572  * See the vsnprintf() documentation for format string extensions over C99.
2573  */
2574 int vsprintf(char *buf, const char *fmt, va_list args)
2575 {
2576 	return vsnprintf(buf, INT_MAX, fmt, args);
2577 }
2578 EXPORT_SYMBOL(vsprintf);
2579 
2580 /**
2581  * sprintf - Format a string and place it in a buffer
2582  * @buf: The buffer to place the result into
2583  * @fmt: The format string to use
2584  * @...: Arguments for the format string
2585  *
2586  * The function returns the number of characters written
2587  * into @buf. Use snprintf() or scnprintf() in order to avoid
2588  * buffer overflows.
2589  *
2590  * See the vsnprintf() documentation for format string extensions over C99.
2591  */
2592 int sprintf(char *buf, const char *fmt, ...)
2593 {
2594 	va_list args;
2595 	int i;
2596 
2597 	va_start(args, fmt);
2598 	i = vsnprintf(buf, INT_MAX, fmt, args);
2599 	va_end(args);
2600 
2601 	return i;
2602 }
2603 EXPORT_SYMBOL(sprintf);
2604 
2605 #ifdef CONFIG_BINARY_PRINTF
2606 /*
2607  * bprintf service:
2608  * vbin_printf() - VA arguments to binary data
2609  * bstr_printf() - Binary data to text string
2610  */
2611 
2612 /**
2613  * vbin_printf - Parse a format string and place args' binary value in a buffer
2614  * @bin_buf: The buffer to place args' binary value
2615  * @size: The size of the buffer(by words(32bits), not characters)
2616  * @fmt: The format string to use
2617  * @args: Arguments for the format string
2618  *
2619  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2620  * is skipped.
2621  *
2622  * The return value is the number of words(32bits) which would be generated for
2623  * the given input.
2624  *
2625  * NOTE:
2626  * If the return value is greater than @size, the resulting bin_buf is NOT
2627  * valid for bstr_printf().
2628  */
2629 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2630 {
2631 	struct printf_spec spec = {0};
2632 	char *str, *end;
2633 	int width;
2634 
2635 	str = (char *)bin_buf;
2636 	end = (char *)(bin_buf + size);
2637 
2638 #define save_arg(type)							\
2639 ({									\
2640 	unsigned long long value;					\
2641 	if (sizeof(type) == 8) {					\
2642 		unsigned long long val8;				\
2643 		str = PTR_ALIGN(str, sizeof(u32));			\
2644 		val8 = va_arg(args, unsigned long long);		\
2645 		if (str + sizeof(type) <= end) {			\
2646 			*(u32 *)str = *(u32 *)&val8;			\
2647 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
2648 		}							\
2649 		value = val8;						\
2650 	} else {							\
2651 		unsigned int val4;					\
2652 		str = PTR_ALIGN(str, sizeof(type));			\
2653 		val4 = va_arg(args, int);				\
2654 		if (str + sizeof(type) <= end)				\
2655 			*(typeof(type) *)str = (type)(long)val4;	\
2656 		value = (unsigned long long)val4;			\
2657 	}								\
2658 	str += sizeof(type);						\
2659 	value;								\
2660 })
2661 
2662 	while (*fmt) {
2663 		int read = format_decode(fmt, &spec);
2664 
2665 		fmt += read;
2666 
2667 		switch (spec.type) {
2668 		case FORMAT_TYPE_NONE:
2669 		case FORMAT_TYPE_PERCENT_CHAR:
2670 			break;
2671 		case FORMAT_TYPE_INVALID:
2672 			goto out;
2673 
2674 		case FORMAT_TYPE_WIDTH:
2675 		case FORMAT_TYPE_PRECISION:
2676 			width = (int)save_arg(int);
2677 			/* Pointers may require the width */
2678 			if (*fmt == 'p')
2679 				set_field_width(&spec, width);
2680 			break;
2681 
2682 		case FORMAT_TYPE_CHAR:
2683 			save_arg(char);
2684 			break;
2685 
2686 		case FORMAT_TYPE_STR: {
2687 			const char *save_str = va_arg(args, char *);
2688 			size_t len;
2689 
2690 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2691 					|| (unsigned long)save_str < PAGE_SIZE)
2692 				save_str = "(null)";
2693 			len = strlen(save_str) + 1;
2694 			if (str + len < end)
2695 				memcpy(str, save_str, len);
2696 			str += len;
2697 			break;
2698 		}
2699 
2700 		case FORMAT_TYPE_PTR:
2701 			/* Dereferenced pointers must be done now */
2702 			switch (*fmt) {
2703 			/* Dereference of functions is still OK */
2704 			case 'S':
2705 			case 's':
2706 			case 'F':
2707 			case 'f':
2708 			case 'x':
2709 			case 'K':
2710 				save_arg(void *);
2711 				break;
2712 			default:
2713 				if (!isalnum(*fmt)) {
2714 					save_arg(void *);
2715 					break;
2716 				}
2717 				str = pointer(fmt, str, end, va_arg(args, void *),
2718 					      spec);
2719 				if (str + 1 < end)
2720 					*str++ = '\0';
2721 				else
2722 					end[-1] = '\0'; /* Must be nul terminated */
2723 			}
2724 			/* skip all alphanumeric pointer suffixes */
2725 			while (isalnum(*fmt))
2726 				fmt++;
2727 			break;
2728 
2729 		default:
2730 			switch (spec.type) {
2731 
2732 			case FORMAT_TYPE_LONG_LONG:
2733 				save_arg(long long);
2734 				break;
2735 			case FORMAT_TYPE_ULONG:
2736 			case FORMAT_TYPE_LONG:
2737 				save_arg(unsigned long);
2738 				break;
2739 			case FORMAT_TYPE_SIZE_T:
2740 				save_arg(size_t);
2741 				break;
2742 			case FORMAT_TYPE_PTRDIFF:
2743 				save_arg(ptrdiff_t);
2744 				break;
2745 			case FORMAT_TYPE_UBYTE:
2746 			case FORMAT_TYPE_BYTE:
2747 				save_arg(char);
2748 				break;
2749 			case FORMAT_TYPE_USHORT:
2750 			case FORMAT_TYPE_SHORT:
2751 				save_arg(short);
2752 				break;
2753 			default:
2754 				save_arg(int);
2755 			}
2756 		}
2757 	}
2758 
2759 out:
2760 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2761 #undef save_arg
2762 }
2763 EXPORT_SYMBOL_GPL(vbin_printf);
2764 
2765 /**
2766  * bstr_printf - Format a string from binary arguments and place it in a buffer
2767  * @buf: The buffer to place the result into
2768  * @size: The size of the buffer, including the trailing null space
2769  * @fmt: The format string to use
2770  * @bin_buf: Binary arguments for the format string
2771  *
2772  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2773  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2774  * a binary buffer that generated by vbin_printf.
2775  *
2776  * The format follows C99 vsnprintf, but has some extensions:
2777  *  see vsnprintf comment for details.
2778  *
2779  * The return value is the number of characters which would
2780  * be generated for the given input, excluding the trailing
2781  * '\0', as per ISO C99. If you want to have the exact
2782  * number of characters written into @buf as return value
2783  * (not including the trailing '\0'), use vscnprintf(). If the
2784  * return is greater than or equal to @size, the resulting
2785  * string is truncated.
2786  */
2787 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2788 {
2789 	struct printf_spec spec = {0};
2790 	char *str, *end;
2791 	const char *args = (const char *)bin_buf;
2792 
2793 	if (WARN_ON_ONCE(size > INT_MAX))
2794 		return 0;
2795 
2796 	str = buf;
2797 	end = buf + size;
2798 
2799 #define get_arg(type)							\
2800 ({									\
2801 	typeof(type) value;						\
2802 	if (sizeof(type) == 8) {					\
2803 		args = PTR_ALIGN(args, sizeof(u32));			\
2804 		*(u32 *)&value = *(u32 *)args;				\
2805 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2806 	} else {							\
2807 		args = PTR_ALIGN(args, sizeof(type));			\
2808 		value = *(typeof(type) *)args;				\
2809 	}								\
2810 	args += sizeof(type);						\
2811 	value;								\
2812 })
2813 
2814 	/* Make sure end is always >= buf */
2815 	if (end < buf) {
2816 		end = ((void *)-1);
2817 		size = end - buf;
2818 	}
2819 
2820 	while (*fmt) {
2821 		const char *old_fmt = fmt;
2822 		int read = format_decode(fmt, &spec);
2823 
2824 		fmt += read;
2825 
2826 		switch (spec.type) {
2827 		case FORMAT_TYPE_NONE: {
2828 			int copy = read;
2829 			if (str < end) {
2830 				if (copy > end - str)
2831 					copy = end - str;
2832 				memcpy(str, old_fmt, copy);
2833 			}
2834 			str += read;
2835 			break;
2836 		}
2837 
2838 		case FORMAT_TYPE_WIDTH:
2839 			set_field_width(&spec, get_arg(int));
2840 			break;
2841 
2842 		case FORMAT_TYPE_PRECISION:
2843 			set_precision(&spec, get_arg(int));
2844 			break;
2845 
2846 		case FORMAT_TYPE_CHAR: {
2847 			char c;
2848 
2849 			if (!(spec.flags & LEFT)) {
2850 				while (--spec.field_width > 0) {
2851 					if (str < end)
2852 						*str = ' ';
2853 					++str;
2854 				}
2855 			}
2856 			c = (unsigned char) get_arg(char);
2857 			if (str < end)
2858 				*str = c;
2859 			++str;
2860 			while (--spec.field_width > 0) {
2861 				if (str < end)
2862 					*str = ' ';
2863 				++str;
2864 			}
2865 			break;
2866 		}
2867 
2868 		case FORMAT_TYPE_STR: {
2869 			const char *str_arg = args;
2870 			args += strlen(str_arg) + 1;
2871 			str = string(str, end, (char *)str_arg, spec);
2872 			break;
2873 		}
2874 
2875 		case FORMAT_TYPE_PTR: {
2876 			bool process = false;
2877 			int copy, len;
2878 			/* Non function dereferences were already done */
2879 			switch (*fmt) {
2880 			case 'S':
2881 			case 's':
2882 			case 'F':
2883 			case 'f':
2884 			case 'x':
2885 			case 'K':
2886 				process = true;
2887 				break;
2888 			default:
2889 				if (!isalnum(*fmt)) {
2890 					process = true;
2891 					break;
2892 				}
2893 				/* Pointer dereference was already processed */
2894 				if (str < end) {
2895 					len = copy = strlen(args);
2896 					if (copy > end - str)
2897 						copy = end - str;
2898 					memcpy(str, args, copy);
2899 					str += len;
2900 					args += len + 1;
2901 				}
2902 			}
2903 			if (process)
2904 				str = pointer(fmt, str, end, get_arg(void *), spec);
2905 
2906 			while (isalnum(*fmt))
2907 				fmt++;
2908 			break;
2909 		}
2910 
2911 		case FORMAT_TYPE_PERCENT_CHAR:
2912 			if (str < end)
2913 				*str = '%';
2914 			++str;
2915 			break;
2916 
2917 		case FORMAT_TYPE_INVALID:
2918 			goto out;
2919 
2920 		default: {
2921 			unsigned long long num;
2922 
2923 			switch (spec.type) {
2924 
2925 			case FORMAT_TYPE_LONG_LONG:
2926 				num = get_arg(long long);
2927 				break;
2928 			case FORMAT_TYPE_ULONG:
2929 			case FORMAT_TYPE_LONG:
2930 				num = get_arg(unsigned long);
2931 				break;
2932 			case FORMAT_TYPE_SIZE_T:
2933 				num = get_arg(size_t);
2934 				break;
2935 			case FORMAT_TYPE_PTRDIFF:
2936 				num = get_arg(ptrdiff_t);
2937 				break;
2938 			case FORMAT_TYPE_UBYTE:
2939 				num = get_arg(unsigned char);
2940 				break;
2941 			case FORMAT_TYPE_BYTE:
2942 				num = get_arg(signed char);
2943 				break;
2944 			case FORMAT_TYPE_USHORT:
2945 				num = get_arg(unsigned short);
2946 				break;
2947 			case FORMAT_TYPE_SHORT:
2948 				num = get_arg(short);
2949 				break;
2950 			case FORMAT_TYPE_UINT:
2951 				num = get_arg(unsigned int);
2952 				break;
2953 			default:
2954 				num = get_arg(int);
2955 			}
2956 
2957 			str = number(str, end, num, spec);
2958 		} /* default: */
2959 		} /* switch(spec.type) */
2960 	} /* while(*fmt) */
2961 
2962 out:
2963 	if (size > 0) {
2964 		if (str < end)
2965 			*str = '\0';
2966 		else
2967 			end[-1] = '\0';
2968 	}
2969 
2970 #undef get_arg
2971 
2972 	/* the trailing null byte doesn't count towards the total */
2973 	return str - buf;
2974 }
2975 EXPORT_SYMBOL_GPL(bstr_printf);
2976 
2977 /**
2978  * bprintf - Parse a format string and place args' binary value in a buffer
2979  * @bin_buf: The buffer to place args' binary value
2980  * @size: The size of the buffer(by words(32bits), not characters)
2981  * @fmt: The format string to use
2982  * @...: Arguments for the format string
2983  *
2984  * The function returns the number of words(u32) written
2985  * into @bin_buf.
2986  */
2987 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2988 {
2989 	va_list args;
2990 	int ret;
2991 
2992 	va_start(args, fmt);
2993 	ret = vbin_printf(bin_buf, size, fmt, args);
2994 	va_end(args);
2995 
2996 	return ret;
2997 }
2998 EXPORT_SYMBOL_GPL(bprintf);
2999 
3000 #endif /* CONFIG_BINARY_PRINTF */
3001 
3002 /**
3003  * vsscanf - Unformat a buffer into a list of arguments
3004  * @buf:	input buffer
3005  * @fmt:	format of buffer
3006  * @args:	arguments
3007  */
3008 int vsscanf(const char *buf, const char *fmt, va_list args)
3009 {
3010 	const char *str = buf;
3011 	char *next;
3012 	char digit;
3013 	int num = 0;
3014 	u8 qualifier;
3015 	unsigned int base;
3016 	union {
3017 		long long s;
3018 		unsigned long long u;
3019 	} val;
3020 	s16 field_width;
3021 	bool is_sign;
3022 
3023 	while (*fmt) {
3024 		/* skip any white space in format */
3025 		/* white space in format matchs any amount of
3026 		 * white space, including none, in the input.
3027 		 */
3028 		if (isspace(*fmt)) {
3029 			fmt = skip_spaces(++fmt);
3030 			str = skip_spaces(str);
3031 		}
3032 
3033 		/* anything that is not a conversion must match exactly */
3034 		if (*fmt != '%' && *fmt) {
3035 			if (*fmt++ != *str++)
3036 				break;
3037 			continue;
3038 		}
3039 
3040 		if (!*fmt)
3041 			break;
3042 		++fmt;
3043 
3044 		/* skip this conversion.
3045 		 * advance both strings to next white space
3046 		 */
3047 		if (*fmt == '*') {
3048 			if (!*str)
3049 				break;
3050 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3051 				/* '%*[' not yet supported, invalid format */
3052 				if (*fmt == '[')
3053 					return num;
3054 				fmt++;
3055 			}
3056 			while (!isspace(*str) && *str)
3057 				str++;
3058 			continue;
3059 		}
3060 
3061 		/* get field width */
3062 		field_width = -1;
3063 		if (isdigit(*fmt)) {
3064 			field_width = skip_atoi(&fmt);
3065 			if (field_width <= 0)
3066 				break;
3067 		}
3068 
3069 		/* get conversion qualifier */
3070 		qualifier = -1;
3071 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3072 		    *fmt == 'z') {
3073 			qualifier = *fmt++;
3074 			if (unlikely(qualifier == *fmt)) {
3075 				if (qualifier == 'h') {
3076 					qualifier = 'H';
3077 					fmt++;
3078 				} else if (qualifier == 'l') {
3079 					qualifier = 'L';
3080 					fmt++;
3081 				}
3082 			}
3083 		}
3084 
3085 		if (!*fmt)
3086 			break;
3087 
3088 		if (*fmt == 'n') {
3089 			/* return number of characters read so far */
3090 			*va_arg(args, int *) = str - buf;
3091 			++fmt;
3092 			continue;
3093 		}
3094 
3095 		if (!*str)
3096 			break;
3097 
3098 		base = 10;
3099 		is_sign = false;
3100 
3101 		switch (*fmt++) {
3102 		case 'c':
3103 		{
3104 			char *s = (char *)va_arg(args, char*);
3105 			if (field_width == -1)
3106 				field_width = 1;
3107 			do {
3108 				*s++ = *str++;
3109 			} while (--field_width > 0 && *str);
3110 			num++;
3111 		}
3112 		continue;
3113 		case 's':
3114 		{
3115 			char *s = (char *)va_arg(args, char *);
3116 			if (field_width == -1)
3117 				field_width = SHRT_MAX;
3118 			/* first, skip leading white space in buffer */
3119 			str = skip_spaces(str);
3120 
3121 			/* now copy until next white space */
3122 			while (*str && !isspace(*str) && field_width--)
3123 				*s++ = *str++;
3124 			*s = '\0';
3125 			num++;
3126 		}
3127 		continue;
3128 		/*
3129 		 * Warning: This implementation of the '[' conversion specifier
3130 		 * deviates from its glibc counterpart in the following ways:
3131 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3132 		 *     character
3133 		 * (2) It cannot match the closing bracket ']' itself
3134 		 * (3) A field width is required
3135 		 * (4) '%*[' (discard matching input) is currently not supported
3136 		 *
3137 		 * Example usage:
3138 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3139 		 *		buf1, buf2, buf3);
3140 		 * if (ret < 3)
3141 		 *    // etc..
3142 		 */
3143 		case '[':
3144 		{
3145 			char *s = (char *)va_arg(args, char *);
3146 			DECLARE_BITMAP(set, 256) = {0};
3147 			unsigned int len = 0;
3148 			bool negate = (*fmt == '^');
3149 
3150 			/* field width is required */
3151 			if (field_width == -1)
3152 				return num;
3153 
3154 			if (negate)
3155 				++fmt;
3156 
3157 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3158 				set_bit((u8)*fmt, set);
3159 
3160 			/* no ']' or no character set found */
3161 			if (!*fmt || !len)
3162 				return num;
3163 			++fmt;
3164 
3165 			if (negate) {
3166 				bitmap_complement(set, set, 256);
3167 				/* exclude null '\0' byte */
3168 				clear_bit(0, set);
3169 			}
3170 
3171 			/* match must be non-empty */
3172 			if (!test_bit((u8)*str, set))
3173 				return num;
3174 
3175 			while (test_bit((u8)*str, set) && field_width--)
3176 				*s++ = *str++;
3177 			*s = '\0';
3178 			++num;
3179 		}
3180 		continue;
3181 		case 'o':
3182 			base = 8;
3183 			break;
3184 		case 'x':
3185 		case 'X':
3186 			base = 16;
3187 			break;
3188 		case 'i':
3189 			base = 0;
3190 			/* fall through */
3191 		case 'd':
3192 			is_sign = true;
3193 			/* fall through */
3194 		case 'u':
3195 			break;
3196 		case '%':
3197 			/* looking for '%' in str */
3198 			if (*str++ != '%')
3199 				return num;
3200 			continue;
3201 		default:
3202 			/* invalid format; stop here */
3203 			return num;
3204 		}
3205 
3206 		/* have some sort of integer conversion.
3207 		 * first, skip white space in buffer.
3208 		 */
3209 		str = skip_spaces(str);
3210 
3211 		digit = *str;
3212 		if (is_sign && digit == '-')
3213 			digit = *(str + 1);
3214 
3215 		if (!digit
3216 		    || (base == 16 && !isxdigit(digit))
3217 		    || (base == 10 && !isdigit(digit))
3218 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
3219 		    || (base == 0 && !isdigit(digit)))
3220 			break;
3221 
3222 		if (is_sign)
3223 			val.s = qualifier != 'L' ?
3224 				simple_strtol(str, &next, base) :
3225 				simple_strtoll(str, &next, base);
3226 		else
3227 			val.u = qualifier != 'L' ?
3228 				simple_strtoul(str, &next, base) :
3229 				simple_strtoull(str, &next, base);
3230 
3231 		if (field_width > 0 && next - str > field_width) {
3232 			if (base == 0)
3233 				_parse_integer_fixup_radix(str, &base);
3234 			while (next - str > field_width) {
3235 				if (is_sign)
3236 					val.s = div_s64(val.s, base);
3237 				else
3238 					val.u = div_u64(val.u, base);
3239 				--next;
3240 			}
3241 		}
3242 
3243 		switch (qualifier) {
3244 		case 'H':	/* that's 'hh' in format */
3245 			if (is_sign)
3246 				*va_arg(args, signed char *) = val.s;
3247 			else
3248 				*va_arg(args, unsigned char *) = val.u;
3249 			break;
3250 		case 'h':
3251 			if (is_sign)
3252 				*va_arg(args, short *) = val.s;
3253 			else
3254 				*va_arg(args, unsigned short *) = val.u;
3255 			break;
3256 		case 'l':
3257 			if (is_sign)
3258 				*va_arg(args, long *) = val.s;
3259 			else
3260 				*va_arg(args, unsigned long *) = val.u;
3261 			break;
3262 		case 'L':
3263 			if (is_sign)
3264 				*va_arg(args, long long *) = val.s;
3265 			else
3266 				*va_arg(args, unsigned long long *) = val.u;
3267 			break;
3268 		case 'z':
3269 			*va_arg(args, size_t *) = val.u;
3270 			break;
3271 		default:
3272 			if (is_sign)
3273 				*va_arg(args, int *) = val.s;
3274 			else
3275 				*va_arg(args, unsigned int *) = val.u;
3276 			break;
3277 		}
3278 		num++;
3279 
3280 		if (!next)
3281 			break;
3282 		str = next;
3283 	}
3284 
3285 	return num;
3286 }
3287 EXPORT_SYMBOL(vsscanf);
3288 
3289 /**
3290  * sscanf - Unformat a buffer into a list of arguments
3291  * @buf:	input buffer
3292  * @fmt:	formatting of buffer
3293  * @...:	resulting arguments
3294  */
3295 int sscanf(const char *buf, const char *fmt, ...)
3296 {
3297 	va_list args;
3298 	int i;
3299 
3300 	va_start(args, fmt);
3301 	i = vsscanf(buf, fmt, args);
3302 	va_end(args);
3303 
3304 	return i;
3305 }
3306 EXPORT_SYMBOL(sscanf);
3307