xref: /openbmc/linux/lib/vsprintf.c (revision 827634ad)
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-provider.h>
21 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/ctype.h>
25 #include <linux/kernel.h>
26 #include <linux/kallsyms.h>
27 #include <linux/math64.h>
28 #include <linux/uaccess.h>
29 #include <linux/ioport.h>
30 #include <linux/dcache.h>
31 #include <linux/cred.h>
32 #include <net/addrconf.h>
33 
34 #include <asm/page.h>		/* for PAGE_SIZE */
35 #include <asm/sections.h>	/* for dereference_function_descriptor() */
36 #include <asm/byteorder.h>	/* cpu_to_le16 */
37 
38 #include <linux/string_helpers.h>
39 #include "kstrtox.h"
40 
41 /**
42  * simple_strtoull - convert a string to an unsigned long long
43  * @cp: The start of the string
44  * @endp: A pointer to the end of the parsed string will be placed here
45  * @base: The number base to use
46  *
47  * This function is obsolete. Please use kstrtoull instead.
48  */
49 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
50 {
51 	unsigned long long result;
52 	unsigned int rv;
53 
54 	cp = _parse_integer_fixup_radix(cp, &base);
55 	rv = _parse_integer(cp, base, &result);
56 	/* FIXME */
57 	cp += (rv & ~KSTRTOX_OVERFLOW);
58 
59 	if (endp)
60 		*endp = (char *)cp;
61 
62 	return result;
63 }
64 EXPORT_SYMBOL(simple_strtoull);
65 
66 /**
67  * simple_strtoul - convert a string to an unsigned long
68  * @cp: The start of the string
69  * @endp: A pointer to the end of the parsed string will be placed here
70  * @base: The number base to use
71  *
72  * This function is obsolete. Please use kstrtoul instead.
73  */
74 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
75 {
76 	return simple_strtoull(cp, endp, base);
77 }
78 EXPORT_SYMBOL(simple_strtoul);
79 
80 /**
81  * simple_strtol - convert a string to a signed long
82  * @cp: The start of the string
83  * @endp: A pointer to the end of the parsed string will be placed here
84  * @base: The number base to use
85  *
86  * This function is obsolete. Please use kstrtol instead.
87  */
88 long simple_strtol(const char *cp, char **endp, unsigned int base)
89 {
90 	if (*cp == '-')
91 		return -simple_strtoul(cp + 1, endp, base);
92 
93 	return simple_strtoul(cp, endp, base);
94 }
95 EXPORT_SYMBOL(simple_strtol);
96 
97 /**
98  * simple_strtoll - convert a string to a signed long long
99  * @cp: The start of the string
100  * @endp: A pointer to the end of the parsed string will be placed here
101  * @base: The number base to use
102  *
103  * This function is obsolete. Please use kstrtoll instead.
104  */
105 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
106 {
107 	if (*cp == '-')
108 		return -simple_strtoull(cp + 1, endp, base);
109 
110 	return simple_strtoull(cp, endp, base);
111 }
112 EXPORT_SYMBOL(simple_strtoll);
113 
114 static noinline_for_stack
115 int skip_atoi(const char **s)
116 {
117 	int i = 0;
118 
119 	do {
120 		i = i*10 + *((*s)++) - '0';
121 	} while (isdigit(**s));
122 
123 	return i;
124 }
125 
126 /*
127  * Decimal conversion is by far the most typical, and is used for
128  * /proc and /sys data. This directly impacts e.g. top performance
129  * with many processes running. We optimize it for speed by emitting
130  * two characters at a time, using a 200 byte lookup table. This
131  * roughly halves the number of multiplications compared to computing
132  * the digits one at a time. Implementation strongly inspired by the
133  * previous version, which in turn used ideas described at
134  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
135  * from the author, Douglas W. Jones).
136  *
137  * It turns out there is precisely one 26 bit fixed-point
138  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
139  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
140  * range happens to be somewhat larger (x <= 1073741898), but that's
141  * irrelevant for our purpose.
142  *
143  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
144  * need a 32x32->64 bit multiply, so we simply use the same constant.
145  *
146  * For dividing a number in the range [100, 10^4-1] by 100, there are
147  * several options. The simplest is (x * 0x147b) >> 19, which is valid
148  * for all x <= 43698.
149  */
150 
151 static const u16 decpair[100] = {
152 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
153 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
154 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
155 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
156 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
157 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
158 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
159 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
160 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
161 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
162 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
163 #undef _
164 };
165 
166 /*
167  * This will print a single '0' even if r == 0, since we would
168  * immediately jump to out_r where two 0s would be written but only
169  * one of them accounted for in buf. This is needed by ip4_string
170  * below. All other callers pass a non-zero value of r.
171 */
172 static noinline_for_stack
173 char *put_dec_trunc8(char *buf, unsigned r)
174 {
175 	unsigned q;
176 
177 	/* 1 <= r < 10^8 */
178 	if (r < 100)
179 		goto out_r;
180 
181 	/* 100 <= r < 10^8 */
182 	q = (r * (u64)0x28f5c29) >> 32;
183 	*((u16 *)buf) = decpair[r - 100*q];
184 	buf += 2;
185 
186 	/* 1 <= q < 10^6 */
187 	if (q < 100)
188 		goto out_q;
189 
190 	/*  100 <= q < 10^6 */
191 	r = (q * (u64)0x28f5c29) >> 32;
192 	*((u16 *)buf) = decpair[q - 100*r];
193 	buf += 2;
194 
195 	/* 1 <= r < 10^4 */
196 	if (r < 100)
197 		goto out_r;
198 
199 	/* 100 <= r < 10^4 */
200 	q = (r * 0x147b) >> 19;
201 	*((u16 *)buf) = decpair[r - 100*q];
202 	buf += 2;
203 out_q:
204 	/* 1 <= q < 100 */
205 	r = q;
206 out_r:
207 	/* 1 <= r < 100 */
208 	*((u16 *)buf) = decpair[r];
209 	buf += r < 10 ? 1 : 2;
210 	return buf;
211 }
212 
213 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
214 static noinline_for_stack
215 char *put_dec_full8(char *buf, unsigned r)
216 {
217 	unsigned q;
218 
219 	/* 0 <= r < 10^8 */
220 	q = (r * (u64)0x28f5c29) >> 32;
221 	*((u16 *)buf) = decpair[r - 100*q];
222 	buf += 2;
223 
224 	/* 0 <= q < 10^6 */
225 	r = (q * (u64)0x28f5c29) >> 32;
226 	*((u16 *)buf) = decpair[q - 100*r];
227 	buf += 2;
228 
229 	/* 0 <= r < 10^4 */
230 	q = (r * 0x147b) >> 19;
231 	*((u16 *)buf) = decpair[r - 100*q];
232 	buf += 2;
233 
234 	/* 0 <= q < 100 */
235 	*((u16 *)buf) = decpair[q];
236 	buf += 2;
237 	return buf;
238 }
239 
240 static noinline_for_stack
241 char *put_dec(char *buf, unsigned long long n)
242 {
243 	if (n >= 100*1000*1000)
244 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
245 	/* 1 <= n <= 1.6e11 */
246 	if (n >= 100*1000*1000)
247 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
248 	/* 1 <= n < 1e8 */
249 	return put_dec_trunc8(buf, n);
250 }
251 
252 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
253 
254 static void
255 put_dec_full4(char *buf, unsigned r)
256 {
257 	unsigned q;
258 
259 	/* 0 <= r < 10^4 */
260 	q = (r * 0x147b) >> 19;
261 	*((u16 *)buf) = decpair[r - 100*q];
262 	buf += 2;
263 	/* 0 <= q < 100 */
264 	*((u16 *)buf) = decpair[q];
265 }
266 
267 /*
268  * Call put_dec_full4 on x % 10000, return x / 10000.
269  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
270  * holds for all x < 1,128,869,999.  The largest value this
271  * helper will ever be asked to convert is 1,125,520,955.
272  * (second call in the put_dec code, assuming n is all-ones).
273  */
274 static noinline_for_stack
275 unsigned put_dec_helper4(char *buf, unsigned x)
276 {
277         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
278 
279         put_dec_full4(buf, x - q * 10000);
280         return q;
281 }
282 
283 /* Based on code by Douglas W. Jones found at
284  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
285  * (with permission from the author).
286  * Performs no 64-bit division and hence should be fast on 32-bit machines.
287  */
288 static
289 char *put_dec(char *buf, unsigned long long n)
290 {
291 	uint32_t d3, d2, d1, q, h;
292 
293 	if (n < 100*1000*1000)
294 		return put_dec_trunc8(buf, n);
295 
296 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
297 	h   = (n >> 32);
298 	d2  = (h      ) & 0xffff;
299 	d3  = (h >> 16); /* implicit "& 0xffff" */
300 
301 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
302 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
303 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
304 	q = put_dec_helper4(buf, q);
305 
306 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
307 	q = put_dec_helper4(buf+4, q);
308 
309 	q += 4749 * d3 + 42 * d2;
310 	q = put_dec_helper4(buf+8, q);
311 
312 	q += 281 * d3;
313 	buf += 12;
314 	if (q)
315 		buf = put_dec_trunc8(buf, q);
316 	else while (buf[-1] == '0')
317 		--buf;
318 
319 	return buf;
320 }
321 
322 #endif
323 
324 /*
325  * Convert passed number to decimal string.
326  * Returns the length of string.  On buffer overflow, returns 0.
327  *
328  * If speed is not important, use snprintf(). It's easy to read the code.
329  */
330 int num_to_str(char *buf, int size, unsigned long long num)
331 {
332 	/* put_dec requires 2-byte alignment of the buffer. */
333 	char tmp[sizeof(num) * 3] __aligned(2);
334 	int idx, len;
335 
336 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
337 	if (num <= 9) {
338 		tmp[0] = '0' + num;
339 		len = 1;
340 	} else {
341 		len = put_dec(tmp, num) - tmp;
342 	}
343 
344 	if (len > size)
345 		return 0;
346 	for (idx = 0; idx < len; ++idx)
347 		buf[idx] = tmp[len - idx - 1];
348 	return len;
349 }
350 
351 #define SIGN	1		/* unsigned/signed, must be 1 */
352 #define LEFT	2		/* left justified */
353 #define PLUS	4		/* show plus */
354 #define SPACE	8		/* space if plus */
355 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
356 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
357 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
358 
359 enum format_type {
360 	FORMAT_TYPE_NONE, /* Just a string part */
361 	FORMAT_TYPE_WIDTH,
362 	FORMAT_TYPE_PRECISION,
363 	FORMAT_TYPE_CHAR,
364 	FORMAT_TYPE_STR,
365 	FORMAT_TYPE_PTR,
366 	FORMAT_TYPE_PERCENT_CHAR,
367 	FORMAT_TYPE_INVALID,
368 	FORMAT_TYPE_LONG_LONG,
369 	FORMAT_TYPE_ULONG,
370 	FORMAT_TYPE_LONG,
371 	FORMAT_TYPE_UBYTE,
372 	FORMAT_TYPE_BYTE,
373 	FORMAT_TYPE_USHORT,
374 	FORMAT_TYPE_SHORT,
375 	FORMAT_TYPE_UINT,
376 	FORMAT_TYPE_INT,
377 	FORMAT_TYPE_SIZE_T,
378 	FORMAT_TYPE_PTRDIFF
379 };
380 
381 struct printf_spec {
382 	u8	type;		/* format_type enum */
383 	u8	flags;		/* flags to number() */
384 	u8	base;		/* number base, 8, 10 or 16 only */
385 	u8	qualifier;	/* number qualifier, one of 'hHlLtzZ' */
386 	s16	field_width;	/* width of output field */
387 	s16	precision;	/* # of digits/chars */
388 };
389 
390 static noinline_for_stack
391 char *number(char *buf, char *end, unsigned long long num,
392 	     struct printf_spec spec)
393 {
394 	/* put_dec requires 2-byte alignment of the buffer. */
395 	char tmp[3 * sizeof(num)] __aligned(2);
396 	char sign;
397 	char locase;
398 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
399 	int i;
400 	bool is_zero = num == 0LL;
401 
402 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
403 	 * produces same digits or (maybe lowercased) letters */
404 	locase = (spec.flags & SMALL);
405 	if (spec.flags & LEFT)
406 		spec.flags &= ~ZEROPAD;
407 	sign = 0;
408 	if (spec.flags & SIGN) {
409 		if ((signed long long)num < 0) {
410 			sign = '-';
411 			num = -(signed long long)num;
412 			spec.field_width--;
413 		} else if (spec.flags & PLUS) {
414 			sign = '+';
415 			spec.field_width--;
416 		} else if (spec.flags & SPACE) {
417 			sign = ' ';
418 			spec.field_width--;
419 		}
420 	}
421 	if (need_pfx) {
422 		if (spec.base == 16)
423 			spec.field_width -= 2;
424 		else if (!is_zero)
425 			spec.field_width--;
426 	}
427 
428 	/* generate full string in tmp[], in reverse order */
429 	i = 0;
430 	if (num < spec.base)
431 		tmp[i++] = hex_asc_upper[num] | locase;
432 	else if (spec.base != 10) { /* 8 or 16 */
433 		int mask = spec.base - 1;
434 		int shift = 3;
435 
436 		if (spec.base == 16)
437 			shift = 4;
438 		do {
439 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
440 			num >>= shift;
441 		} while (num);
442 	} else { /* base 10 */
443 		i = put_dec(tmp, num) - tmp;
444 	}
445 
446 	/* printing 100 using %2d gives "100", not "00" */
447 	if (i > spec.precision)
448 		spec.precision = i;
449 	/* leading space padding */
450 	spec.field_width -= spec.precision;
451 	if (!(spec.flags & (ZEROPAD | LEFT))) {
452 		while (--spec.field_width >= 0) {
453 			if (buf < end)
454 				*buf = ' ';
455 			++buf;
456 		}
457 	}
458 	/* sign */
459 	if (sign) {
460 		if (buf < end)
461 			*buf = sign;
462 		++buf;
463 	}
464 	/* "0x" / "0" prefix */
465 	if (need_pfx) {
466 		if (spec.base == 16 || !is_zero) {
467 			if (buf < end)
468 				*buf = '0';
469 			++buf;
470 		}
471 		if (spec.base == 16) {
472 			if (buf < end)
473 				*buf = ('X' | locase);
474 			++buf;
475 		}
476 	}
477 	/* zero or space padding */
478 	if (!(spec.flags & LEFT)) {
479 		char c = ' ' + (spec.flags & ZEROPAD);
480 		BUILD_BUG_ON(' ' + ZEROPAD != '0');
481 		while (--spec.field_width >= 0) {
482 			if (buf < end)
483 				*buf = c;
484 			++buf;
485 		}
486 	}
487 	/* hmm even more zero padding? */
488 	while (i <= --spec.precision) {
489 		if (buf < end)
490 			*buf = '0';
491 		++buf;
492 	}
493 	/* actual digits of result */
494 	while (--i >= 0) {
495 		if (buf < end)
496 			*buf = tmp[i];
497 		++buf;
498 	}
499 	/* trailing space padding */
500 	while (--spec.field_width >= 0) {
501 		if (buf < end)
502 			*buf = ' ';
503 		++buf;
504 	}
505 
506 	return buf;
507 }
508 
509 static noinline_for_stack
510 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
511 {
512 	int len, i;
513 
514 	if ((unsigned long)s < PAGE_SIZE)
515 		s = "(null)";
516 
517 	len = strnlen(s, spec.precision);
518 
519 	if (!(spec.flags & LEFT)) {
520 		while (len < spec.field_width--) {
521 			if (buf < end)
522 				*buf = ' ';
523 			++buf;
524 		}
525 	}
526 	for (i = 0; i < len; ++i) {
527 		if (buf < end)
528 			*buf = *s;
529 		++buf; ++s;
530 	}
531 	while (len < spec.field_width--) {
532 		if (buf < end)
533 			*buf = ' ';
534 		++buf;
535 	}
536 
537 	return buf;
538 }
539 
540 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
541 {
542 	size_t size;
543 	if (buf >= end)	/* nowhere to put anything */
544 		return;
545 	size = end - buf;
546 	if (size <= spaces) {
547 		memset(buf, ' ', size);
548 		return;
549 	}
550 	if (len) {
551 		if (len > size - spaces)
552 			len = size - spaces;
553 		memmove(buf + spaces, buf, len);
554 	}
555 	memset(buf, ' ', spaces);
556 }
557 
558 static noinline_for_stack
559 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
560 		  const char *fmt)
561 {
562 	const char *array[4], *s;
563 	const struct dentry *p;
564 	int depth;
565 	int i, n;
566 
567 	switch (fmt[1]) {
568 		case '2': case '3': case '4':
569 			depth = fmt[1] - '0';
570 			break;
571 		default:
572 			depth = 1;
573 	}
574 
575 	rcu_read_lock();
576 	for (i = 0; i < depth; i++, d = p) {
577 		p = ACCESS_ONCE(d->d_parent);
578 		array[i] = ACCESS_ONCE(d->d_name.name);
579 		if (p == d) {
580 			if (i)
581 				array[i] = "";
582 			i++;
583 			break;
584 		}
585 	}
586 	s = array[--i];
587 	for (n = 0; n != spec.precision; n++, buf++) {
588 		char c = *s++;
589 		if (!c) {
590 			if (!i)
591 				break;
592 			c = '/';
593 			s = array[--i];
594 		}
595 		if (buf < end)
596 			*buf = c;
597 	}
598 	rcu_read_unlock();
599 	if (n < spec.field_width) {
600 		/* we want to pad the sucker */
601 		unsigned spaces = spec.field_width - n;
602 		if (!(spec.flags & LEFT)) {
603 			widen(buf - n, end, n, spaces);
604 			return buf + spaces;
605 		}
606 		while (spaces--) {
607 			if (buf < end)
608 				*buf = ' ';
609 			++buf;
610 		}
611 	}
612 	return buf;
613 }
614 
615 static noinline_for_stack
616 char *symbol_string(char *buf, char *end, void *ptr,
617 		    struct printf_spec spec, const char *fmt)
618 {
619 	unsigned long value;
620 #ifdef CONFIG_KALLSYMS
621 	char sym[KSYM_SYMBOL_LEN];
622 #endif
623 
624 	if (fmt[1] == 'R')
625 		ptr = __builtin_extract_return_addr(ptr);
626 	value = (unsigned long)ptr;
627 
628 #ifdef CONFIG_KALLSYMS
629 	if (*fmt == 'B')
630 		sprint_backtrace(sym, value);
631 	else if (*fmt != 'f' && *fmt != 's')
632 		sprint_symbol(sym, value);
633 	else
634 		sprint_symbol_no_offset(sym, value);
635 
636 	return string(buf, end, sym, spec);
637 #else
638 	spec.field_width = 2 * sizeof(void *);
639 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
640 	spec.base = 16;
641 
642 	return number(buf, end, value, spec);
643 #endif
644 }
645 
646 static noinline_for_stack
647 char *resource_string(char *buf, char *end, struct resource *res,
648 		      struct printf_spec spec, const char *fmt)
649 {
650 #ifndef IO_RSRC_PRINTK_SIZE
651 #define IO_RSRC_PRINTK_SIZE	6
652 #endif
653 
654 #ifndef MEM_RSRC_PRINTK_SIZE
655 #define MEM_RSRC_PRINTK_SIZE	10
656 #endif
657 	static const struct printf_spec io_spec = {
658 		.base = 16,
659 		.field_width = IO_RSRC_PRINTK_SIZE,
660 		.precision = -1,
661 		.flags = SPECIAL | SMALL | ZEROPAD,
662 	};
663 	static const struct printf_spec mem_spec = {
664 		.base = 16,
665 		.field_width = MEM_RSRC_PRINTK_SIZE,
666 		.precision = -1,
667 		.flags = SPECIAL | SMALL | ZEROPAD,
668 	};
669 	static const struct printf_spec bus_spec = {
670 		.base = 16,
671 		.field_width = 2,
672 		.precision = -1,
673 		.flags = SMALL | ZEROPAD,
674 	};
675 	static const struct printf_spec dec_spec = {
676 		.base = 10,
677 		.precision = -1,
678 		.flags = 0,
679 	};
680 	static const struct printf_spec str_spec = {
681 		.field_width = -1,
682 		.precision = 10,
683 		.flags = LEFT,
684 	};
685 	static const struct printf_spec flag_spec = {
686 		.base = 16,
687 		.precision = -1,
688 		.flags = SPECIAL | SMALL,
689 	};
690 
691 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
692 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
693 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
694 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
695 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
696 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
697 	char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
698 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
699 
700 	char *p = sym, *pend = sym + sizeof(sym);
701 	int decode = (fmt[0] == 'R') ? 1 : 0;
702 	const struct printf_spec *specp;
703 
704 	*p++ = '[';
705 	if (res->flags & IORESOURCE_IO) {
706 		p = string(p, pend, "io  ", str_spec);
707 		specp = &io_spec;
708 	} else if (res->flags & IORESOURCE_MEM) {
709 		p = string(p, pend, "mem ", str_spec);
710 		specp = &mem_spec;
711 	} else if (res->flags & IORESOURCE_IRQ) {
712 		p = string(p, pend, "irq ", str_spec);
713 		specp = &dec_spec;
714 	} else if (res->flags & IORESOURCE_DMA) {
715 		p = string(p, pend, "dma ", str_spec);
716 		specp = &dec_spec;
717 	} else if (res->flags & IORESOURCE_BUS) {
718 		p = string(p, pend, "bus ", str_spec);
719 		specp = &bus_spec;
720 	} else {
721 		p = string(p, pend, "??? ", str_spec);
722 		specp = &mem_spec;
723 		decode = 0;
724 	}
725 	if (decode && res->flags & IORESOURCE_UNSET) {
726 		p = string(p, pend, "size ", str_spec);
727 		p = number(p, pend, resource_size(res), *specp);
728 	} else {
729 		p = number(p, pend, res->start, *specp);
730 		if (res->start != res->end) {
731 			*p++ = '-';
732 			p = number(p, pend, res->end, *specp);
733 		}
734 	}
735 	if (decode) {
736 		if (res->flags & IORESOURCE_MEM_64)
737 			p = string(p, pend, " 64bit", str_spec);
738 		if (res->flags & IORESOURCE_PREFETCH)
739 			p = string(p, pend, " pref", str_spec);
740 		if (res->flags & IORESOURCE_WINDOW)
741 			p = string(p, pend, " window", str_spec);
742 		if (res->flags & IORESOURCE_DISABLED)
743 			p = string(p, pend, " disabled", str_spec);
744 	} else {
745 		p = string(p, pend, " flags ", str_spec);
746 		p = number(p, pend, res->flags, flag_spec);
747 	}
748 	*p++ = ']';
749 	*p = '\0';
750 
751 	return string(buf, end, sym, spec);
752 }
753 
754 static noinline_for_stack
755 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
756 		 const char *fmt)
757 {
758 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
759 				   negative value, fallback to the default */
760 	char separator;
761 
762 	if (spec.field_width == 0)
763 		/* nothing to print */
764 		return buf;
765 
766 	if (ZERO_OR_NULL_PTR(addr))
767 		/* NULL pointer */
768 		return string(buf, end, NULL, spec);
769 
770 	switch (fmt[1]) {
771 	case 'C':
772 		separator = ':';
773 		break;
774 	case 'D':
775 		separator = '-';
776 		break;
777 	case 'N':
778 		separator = 0;
779 		break;
780 	default:
781 		separator = ' ';
782 		break;
783 	}
784 
785 	if (spec.field_width > 0)
786 		len = min_t(int, spec.field_width, 64);
787 
788 	for (i = 0; i < len; ++i) {
789 		if (buf < end)
790 			*buf = hex_asc_hi(addr[i]);
791 		++buf;
792 		if (buf < end)
793 			*buf = hex_asc_lo(addr[i]);
794 		++buf;
795 
796 		if (separator && i != len - 1) {
797 			if (buf < end)
798 				*buf = separator;
799 			++buf;
800 		}
801 	}
802 
803 	return buf;
804 }
805 
806 static noinline_for_stack
807 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
808 		    struct printf_spec spec, const char *fmt)
809 {
810 	const int CHUNKSZ = 32;
811 	int nr_bits = max_t(int, spec.field_width, 0);
812 	int i, chunksz;
813 	bool first = true;
814 
815 	/* reused to print numbers */
816 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
817 
818 	chunksz = nr_bits & (CHUNKSZ - 1);
819 	if (chunksz == 0)
820 		chunksz = CHUNKSZ;
821 
822 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
823 	for (; i >= 0; i -= CHUNKSZ) {
824 		u32 chunkmask, val;
825 		int word, bit;
826 
827 		chunkmask = ((1ULL << chunksz) - 1);
828 		word = i / BITS_PER_LONG;
829 		bit = i % BITS_PER_LONG;
830 		val = (bitmap[word] >> bit) & chunkmask;
831 
832 		if (!first) {
833 			if (buf < end)
834 				*buf = ',';
835 			buf++;
836 		}
837 		first = false;
838 
839 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
840 		buf = number(buf, end, val, spec);
841 
842 		chunksz = CHUNKSZ;
843 	}
844 	return buf;
845 }
846 
847 static noinline_for_stack
848 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
849 			 struct printf_spec spec, const char *fmt)
850 {
851 	int nr_bits = max_t(int, spec.field_width, 0);
852 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
853 	int cur, rbot, rtop;
854 	bool first = true;
855 
856 	/* reused to print numbers */
857 	spec = (struct printf_spec){ .base = 10 };
858 
859 	rbot = cur = find_first_bit(bitmap, nr_bits);
860 	while (cur < nr_bits) {
861 		rtop = cur;
862 		cur = find_next_bit(bitmap, nr_bits, cur + 1);
863 		if (cur < nr_bits && cur <= rtop + 1)
864 			continue;
865 
866 		if (!first) {
867 			if (buf < end)
868 				*buf = ',';
869 			buf++;
870 		}
871 		first = false;
872 
873 		buf = number(buf, end, rbot, spec);
874 		if (rbot < rtop) {
875 			if (buf < end)
876 				*buf = '-';
877 			buf++;
878 
879 			buf = number(buf, end, rtop, spec);
880 		}
881 
882 		rbot = cur;
883 	}
884 	return buf;
885 }
886 
887 static noinline_for_stack
888 char *mac_address_string(char *buf, char *end, u8 *addr,
889 			 struct printf_spec spec, const char *fmt)
890 {
891 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
892 	char *p = mac_addr;
893 	int i;
894 	char separator;
895 	bool reversed = false;
896 
897 	switch (fmt[1]) {
898 	case 'F':
899 		separator = '-';
900 		break;
901 
902 	case 'R':
903 		reversed = true;
904 		/* fall through */
905 
906 	default:
907 		separator = ':';
908 		break;
909 	}
910 
911 	for (i = 0; i < 6; i++) {
912 		if (reversed)
913 			p = hex_byte_pack(p, addr[5 - i]);
914 		else
915 			p = hex_byte_pack(p, addr[i]);
916 
917 		if (fmt[0] == 'M' && i != 5)
918 			*p++ = separator;
919 	}
920 	*p = '\0';
921 
922 	return string(buf, end, mac_addr, spec);
923 }
924 
925 static noinline_for_stack
926 char *ip4_string(char *p, const u8 *addr, const char *fmt)
927 {
928 	int i;
929 	bool leading_zeros = (fmt[0] == 'i');
930 	int index;
931 	int step;
932 
933 	switch (fmt[2]) {
934 	case 'h':
935 #ifdef __BIG_ENDIAN
936 		index = 0;
937 		step = 1;
938 #else
939 		index = 3;
940 		step = -1;
941 #endif
942 		break;
943 	case 'l':
944 		index = 3;
945 		step = -1;
946 		break;
947 	case 'n':
948 	case 'b':
949 	default:
950 		index = 0;
951 		step = 1;
952 		break;
953 	}
954 	for (i = 0; i < 4; i++) {
955 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
956 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
957 		if (leading_zeros) {
958 			if (digits < 3)
959 				*p++ = '0';
960 			if (digits < 2)
961 				*p++ = '0';
962 		}
963 		/* reverse the digits in the quad */
964 		while (digits--)
965 			*p++ = temp[digits];
966 		if (i < 3)
967 			*p++ = '.';
968 		index += step;
969 	}
970 	*p = '\0';
971 
972 	return p;
973 }
974 
975 static noinline_for_stack
976 char *ip6_compressed_string(char *p, const char *addr)
977 {
978 	int i, j, range;
979 	unsigned char zerolength[8];
980 	int longest = 1;
981 	int colonpos = -1;
982 	u16 word;
983 	u8 hi, lo;
984 	bool needcolon = false;
985 	bool useIPv4;
986 	struct in6_addr in6;
987 
988 	memcpy(&in6, addr, sizeof(struct in6_addr));
989 
990 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
991 
992 	memset(zerolength, 0, sizeof(zerolength));
993 
994 	if (useIPv4)
995 		range = 6;
996 	else
997 		range = 8;
998 
999 	/* find position of longest 0 run */
1000 	for (i = 0; i < range; i++) {
1001 		for (j = i; j < range; j++) {
1002 			if (in6.s6_addr16[j] != 0)
1003 				break;
1004 			zerolength[i]++;
1005 		}
1006 	}
1007 	for (i = 0; i < range; i++) {
1008 		if (zerolength[i] > longest) {
1009 			longest = zerolength[i];
1010 			colonpos = i;
1011 		}
1012 	}
1013 	if (longest == 1)		/* don't compress a single 0 */
1014 		colonpos = -1;
1015 
1016 	/* emit address */
1017 	for (i = 0; i < range; i++) {
1018 		if (i == colonpos) {
1019 			if (needcolon || i == 0)
1020 				*p++ = ':';
1021 			*p++ = ':';
1022 			needcolon = false;
1023 			i += longest - 1;
1024 			continue;
1025 		}
1026 		if (needcolon) {
1027 			*p++ = ':';
1028 			needcolon = false;
1029 		}
1030 		/* hex u16 without leading 0s */
1031 		word = ntohs(in6.s6_addr16[i]);
1032 		hi = word >> 8;
1033 		lo = word & 0xff;
1034 		if (hi) {
1035 			if (hi > 0x0f)
1036 				p = hex_byte_pack(p, hi);
1037 			else
1038 				*p++ = hex_asc_lo(hi);
1039 			p = hex_byte_pack(p, lo);
1040 		}
1041 		else if (lo > 0x0f)
1042 			p = hex_byte_pack(p, lo);
1043 		else
1044 			*p++ = hex_asc_lo(lo);
1045 		needcolon = true;
1046 	}
1047 
1048 	if (useIPv4) {
1049 		if (needcolon)
1050 			*p++ = ':';
1051 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1052 	}
1053 	*p = '\0';
1054 
1055 	return p;
1056 }
1057 
1058 static noinline_for_stack
1059 char *ip6_string(char *p, const char *addr, const char *fmt)
1060 {
1061 	int i;
1062 
1063 	for (i = 0; i < 8; i++) {
1064 		p = hex_byte_pack(p, *addr++);
1065 		p = hex_byte_pack(p, *addr++);
1066 		if (fmt[0] == 'I' && i != 7)
1067 			*p++ = ':';
1068 	}
1069 	*p = '\0';
1070 
1071 	return p;
1072 }
1073 
1074 static noinline_for_stack
1075 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1076 		      struct printf_spec spec, const char *fmt)
1077 {
1078 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1079 
1080 	if (fmt[0] == 'I' && fmt[2] == 'c')
1081 		ip6_compressed_string(ip6_addr, addr);
1082 	else
1083 		ip6_string(ip6_addr, addr, fmt);
1084 
1085 	return string(buf, end, ip6_addr, spec);
1086 }
1087 
1088 static noinline_for_stack
1089 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1090 		      struct printf_spec spec, const char *fmt)
1091 {
1092 	char ip4_addr[sizeof("255.255.255.255")];
1093 
1094 	ip4_string(ip4_addr, addr, fmt);
1095 
1096 	return string(buf, end, ip4_addr, spec);
1097 }
1098 
1099 static noinline_for_stack
1100 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1101 			 struct printf_spec spec, const char *fmt)
1102 {
1103 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1104 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1105 		      sizeof(":12345") + sizeof("/123456789") +
1106 		      sizeof("%1234567890")];
1107 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1108 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1109 	char fmt6[2] = { fmt[0], '6' };
1110 	u8 off = 0;
1111 
1112 	fmt++;
1113 	while (isalpha(*++fmt)) {
1114 		switch (*fmt) {
1115 		case 'p':
1116 			have_p = true;
1117 			break;
1118 		case 'f':
1119 			have_f = true;
1120 			break;
1121 		case 's':
1122 			have_s = true;
1123 			break;
1124 		case 'c':
1125 			have_c = true;
1126 			break;
1127 		}
1128 	}
1129 
1130 	if (have_p || have_s || have_f) {
1131 		*p = '[';
1132 		off = 1;
1133 	}
1134 
1135 	if (fmt6[0] == 'I' && have_c)
1136 		p = ip6_compressed_string(ip6_addr + off, addr);
1137 	else
1138 		p = ip6_string(ip6_addr + off, addr, fmt6);
1139 
1140 	if (have_p || have_s || have_f)
1141 		*p++ = ']';
1142 
1143 	if (have_p) {
1144 		*p++ = ':';
1145 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1146 	}
1147 	if (have_f) {
1148 		*p++ = '/';
1149 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1150 					  IPV6_FLOWINFO_MASK), spec);
1151 	}
1152 	if (have_s) {
1153 		*p++ = '%';
1154 		p = number(p, pend, sa->sin6_scope_id, spec);
1155 	}
1156 	*p = '\0';
1157 
1158 	return string(buf, end, ip6_addr, spec);
1159 }
1160 
1161 static noinline_for_stack
1162 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1163 			 struct printf_spec spec, const char *fmt)
1164 {
1165 	bool have_p = false;
1166 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1167 	char *pend = ip4_addr + sizeof(ip4_addr);
1168 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1169 	char fmt4[3] = { fmt[0], '4', 0 };
1170 
1171 	fmt++;
1172 	while (isalpha(*++fmt)) {
1173 		switch (*fmt) {
1174 		case 'p':
1175 			have_p = true;
1176 			break;
1177 		case 'h':
1178 		case 'l':
1179 		case 'n':
1180 		case 'b':
1181 			fmt4[2] = *fmt;
1182 			break;
1183 		}
1184 	}
1185 
1186 	p = ip4_string(ip4_addr, addr, fmt4);
1187 	if (have_p) {
1188 		*p++ = ':';
1189 		p = number(p, pend, ntohs(sa->sin_port), spec);
1190 	}
1191 	*p = '\0';
1192 
1193 	return string(buf, end, ip4_addr, spec);
1194 }
1195 
1196 static noinline_for_stack
1197 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1198 		     const char *fmt)
1199 {
1200 	bool found = true;
1201 	int count = 1;
1202 	unsigned int flags = 0;
1203 	int len;
1204 
1205 	if (spec.field_width == 0)
1206 		return buf;				/* nothing to print */
1207 
1208 	if (ZERO_OR_NULL_PTR(addr))
1209 		return string(buf, end, NULL, spec);	/* NULL pointer */
1210 
1211 
1212 	do {
1213 		switch (fmt[count++]) {
1214 		case 'a':
1215 			flags |= ESCAPE_ANY;
1216 			break;
1217 		case 'c':
1218 			flags |= ESCAPE_SPECIAL;
1219 			break;
1220 		case 'h':
1221 			flags |= ESCAPE_HEX;
1222 			break;
1223 		case 'n':
1224 			flags |= ESCAPE_NULL;
1225 			break;
1226 		case 'o':
1227 			flags |= ESCAPE_OCTAL;
1228 			break;
1229 		case 'p':
1230 			flags |= ESCAPE_NP;
1231 			break;
1232 		case 's':
1233 			flags |= ESCAPE_SPACE;
1234 			break;
1235 		default:
1236 			found = false;
1237 			break;
1238 		}
1239 	} while (found);
1240 
1241 	if (!flags)
1242 		flags = ESCAPE_ANY_NP;
1243 
1244 	len = spec.field_width < 0 ? 1 : spec.field_width;
1245 
1246 	/*
1247 	 * string_escape_mem() writes as many characters as it can to
1248 	 * the given buffer, and returns the total size of the output
1249 	 * had the buffer been big enough.
1250 	 */
1251 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1252 
1253 	return buf;
1254 }
1255 
1256 static noinline_for_stack
1257 char *uuid_string(char *buf, char *end, const u8 *addr,
1258 		  struct printf_spec spec, const char *fmt)
1259 {
1260 	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1261 	char *p = uuid;
1262 	int i;
1263 	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1264 	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1265 	const u8 *index = be;
1266 	bool uc = false;
1267 
1268 	switch (*(++fmt)) {
1269 	case 'L':
1270 		uc = true;		/* fall-through */
1271 	case 'l':
1272 		index = le;
1273 		break;
1274 	case 'B':
1275 		uc = true;
1276 		break;
1277 	}
1278 
1279 	for (i = 0; i < 16; i++) {
1280 		p = hex_byte_pack(p, addr[index[i]]);
1281 		switch (i) {
1282 		case 3:
1283 		case 5:
1284 		case 7:
1285 		case 9:
1286 			*p++ = '-';
1287 			break;
1288 		}
1289 	}
1290 
1291 	*p = 0;
1292 
1293 	if (uc) {
1294 		p = uuid;
1295 		do {
1296 			*p = toupper(*p);
1297 		} while (*(++p));
1298 	}
1299 
1300 	return string(buf, end, uuid, spec);
1301 }
1302 
1303 static
1304 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1305 		      struct printf_spec spec)
1306 {
1307 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1308 	if (spec.field_width == -1)
1309 		spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1310 	spec.base = 16;
1311 
1312 	return number(buf, end, *(const netdev_features_t *)addr, spec);
1313 }
1314 
1315 static noinline_for_stack
1316 char *address_val(char *buf, char *end, const void *addr,
1317 		  struct printf_spec spec, const char *fmt)
1318 {
1319 	unsigned long long num;
1320 
1321 	spec.flags |= SPECIAL | SMALL | ZEROPAD;
1322 	spec.base = 16;
1323 
1324 	switch (fmt[1]) {
1325 	case 'd':
1326 		num = *(const dma_addr_t *)addr;
1327 		spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1328 		break;
1329 	case 'p':
1330 	default:
1331 		num = *(const phys_addr_t *)addr;
1332 		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1333 		break;
1334 	}
1335 
1336 	return number(buf, end, num, spec);
1337 }
1338 
1339 static noinline_for_stack
1340 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1341 	    const char *fmt)
1342 {
1343 	if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1344 		return string(buf, end, NULL, spec);
1345 
1346 	switch (fmt[1]) {
1347 	case 'r':
1348 		return number(buf, end, clk_get_rate(clk), spec);
1349 
1350 	case 'n':
1351 	default:
1352 #ifdef CONFIG_COMMON_CLK
1353 		return string(buf, end, __clk_get_name(clk), spec);
1354 #else
1355 		spec.base = 16;
1356 		spec.field_width = sizeof(unsigned long) * 2 + 2;
1357 		spec.flags |= SPECIAL | SMALL | ZEROPAD;
1358 		return number(buf, end, (unsigned long)clk, spec);
1359 #endif
1360 	}
1361 }
1362 
1363 int kptr_restrict __read_mostly;
1364 
1365 /*
1366  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1367  * by an extra set of alphanumeric characters that are extended format
1368  * specifiers.
1369  *
1370  * Right now we handle:
1371  *
1372  * - 'F' For symbolic function descriptor pointers with offset
1373  * - 'f' For simple symbolic function names without offset
1374  * - 'S' For symbolic direct pointers with offset
1375  * - 's' For symbolic direct pointers without offset
1376  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1377  * - 'B' For backtraced symbolic direct pointers with offset
1378  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1379  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1380  * - 'b[l]' For a bitmap, the number of bits is determined by the field
1381  *       width which must be explicitly specified either as part of the
1382  *       format string '%32b[l]' or through '%*b[l]', [l] selects
1383  *       range-list format instead of hex format
1384  * - 'M' For a 6-byte MAC address, it prints the address in the
1385  *       usual colon-separated hex notation
1386  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1387  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1388  *       with a dash-separated hex notation
1389  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1390  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1391  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1392  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1393  *       [S][pfs]
1394  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1395  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1396  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1397  *       IPv6 omits the colons (01020304...0f)
1398  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1399  *       [S][pfs]
1400  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1401  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1402  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1403  * - 'I[6S]c' for IPv6 addresses printed as specified by
1404  *       http://tools.ietf.org/html/rfc5952
1405  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1406  *                of the following flags (see string_escape_mem() for the
1407  *                details):
1408  *                  a - ESCAPE_ANY
1409  *                  c - ESCAPE_SPECIAL
1410  *                  h - ESCAPE_HEX
1411  *                  n - ESCAPE_NULL
1412  *                  o - ESCAPE_OCTAL
1413  *                  p - ESCAPE_NP
1414  *                  s - ESCAPE_SPACE
1415  *                By default ESCAPE_ANY_NP is used.
1416  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1417  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1418  *       Options for %pU are:
1419  *         b big endian lower case hex (default)
1420  *         B big endian UPPER case hex
1421  *         l little endian lower case hex
1422  *         L little endian UPPER case hex
1423  *           big endian output byte order is:
1424  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1425  *           little endian output byte order is:
1426  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1427  * - 'V' For a struct va_format which contains a format string * and va_list *,
1428  *       call vsnprintf(->format, *->va_list).
1429  *       Implements a "recursive vsnprintf".
1430  *       Do not use this feature without some mechanism to verify the
1431  *       correctness of the format string and va_list arguments.
1432  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1433  * - 'NF' For a netdev_features_t
1434  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1435  *            a certain separator (' ' by default):
1436  *              C colon
1437  *              D dash
1438  *              N no separator
1439  *            The maximum supported length is 64 bytes of the input. Consider
1440  *            to use print_hex_dump() for the larger input.
1441  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1442  *           (default assumed to be phys_addr_t, passed by reference)
1443  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1444  * - 'D[234]' Same as 'd' but for a struct file
1445  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1446  *       (legacy clock framework) of the clock
1447  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1448  *        (legacy clock framework) of the clock
1449  * - 'Cr' For a clock, it prints the current rate of the clock
1450  *
1451  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1452  * function pointers are really function descriptors, which contain a
1453  * pointer to the real address.
1454  */
1455 static noinline_for_stack
1456 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1457 	      struct printf_spec spec)
1458 {
1459 	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1460 
1461 	if (!ptr && *fmt != 'K') {
1462 		/*
1463 		 * Print (null) with the same width as a pointer so it makes
1464 		 * tabular output look nice.
1465 		 */
1466 		if (spec.field_width == -1)
1467 			spec.field_width = default_width;
1468 		return string(buf, end, "(null)", spec);
1469 	}
1470 
1471 	switch (*fmt) {
1472 	case 'F':
1473 	case 'f':
1474 		ptr = dereference_function_descriptor(ptr);
1475 		/* Fallthrough */
1476 	case 'S':
1477 	case 's':
1478 	case 'B':
1479 		return symbol_string(buf, end, ptr, spec, fmt);
1480 	case 'R':
1481 	case 'r':
1482 		return resource_string(buf, end, ptr, spec, fmt);
1483 	case 'h':
1484 		return hex_string(buf, end, ptr, spec, fmt);
1485 	case 'b':
1486 		switch (fmt[1]) {
1487 		case 'l':
1488 			return bitmap_list_string(buf, end, ptr, spec, fmt);
1489 		default:
1490 			return bitmap_string(buf, end, ptr, spec, fmt);
1491 		}
1492 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
1493 	case 'm':			/* Contiguous: 000102030405 */
1494 					/* [mM]F (FDDI) */
1495 					/* [mM]R (Reverse order; Bluetooth) */
1496 		return mac_address_string(buf, end, ptr, spec, fmt);
1497 	case 'I':			/* Formatted IP supported
1498 					 * 4:	1.2.3.4
1499 					 * 6:	0001:0203:...:0708
1500 					 * 6c:	1::708 or 1::1.2.3.4
1501 					 */
1502 	case 'i':			/* Contiguous:
1503 					 * 4:	001.002.003.004
1504 					 * 6:   000102...0f
1505 					 */
1506 		switch (fmt[1]) {
1507 		case '6':
1508 			return ip6_addr_string(buf, end, ptr, spec, fmt);
1509 		case '4':
1510 			return ip4_addr_string(buf, end, ptr, spec, fmt);
1511 		case 'S': {
1512 			const union {
1513 				struct sockaddr		raw;
1514 				struct sockaddr_in	v4;
1515 				struct sockaddr_in6	v6;
1516 			} *sa = ptr;
1517 
1518 			switch (sa->raw.sa_family) {
1519 			case AF_INET:
1520 				return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1521 			case AF_INET6:
1522 				return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1523 			default:
1524 				return string(buf, end, "(invalid address)", spec);
1525 			}}
1526 		}
1527 		break;
1528 	case 'E':
1529 		return escaped_string(buf, end, ptr, spec, fmt);
1530 	case 'U':
1531 		return uuid_string(buf, end, ptr, spec, fmt);
1532 	case 'V':
1533 		{
1534 			va_list va;
1535 
1536 			va_copy(va, *((struct va_format *)ptr)->va);
1537 			buf += vsnprintf(buf, end > buf ? end - buf : 0,
1538 					 ((struct va_format *)ptr)->fmt, va);
1539 			va_end(va);
1540 			return buf;
1541 		}
1542 	case 'K':
1543 		/*
1544 		 * %pK cannot be used in IRQ context because its test
1545 		 * for CAP_SYSLOG would be meaningless.
1546 		 */
1547 		if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1548 				      in_nmi())) {
1549 			if (spec.field_width == -1)
1550 				spec.field_width = default_width;
1551 			return string(buf, end, "pK-error", spec);
1552 		}
1553 
1554 		switch (kptr_restrict) {
1555 		case 0:
1556 			/* Always print %pK values */
1557 			break;
1558 		case 1: {
1559 			/*
1560 			 * Only print the real pointer value if the current
1561 			 * process has CAP_SYSLOG and is running with the
1562 			 * same credentials it started with. This is because
1563 			 * access to files is checked at open() time, but %pK
1564 			 * checks permission at read() time. We don't want to
1565 			 * leak pointer values if a binary opens a file using
1566 			 * %pK and then elevates privileges before reading it.
1567 			 */
1568 			const struct cred *cred = current_cred();
1569 
1570 			if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1571 			    !uid_eq(cred->euid, cred->uid) ||
1572 			    !gid_eq(cred->egid, cred->gid))
1573 				ptr = NULL;
1574 			break;
1575 		}
1576 		case 2:
1577 		default:
1578 			/* Always print 0's for %pK */
1579 			ptr = NULL;
1580 			break;
1581 		}
1582 		break;
1583 
1584 	case 'N':
1585 		switch (fmt[1]) {
1586 		case 'F':
1587 			return netdev_feature_string(buf, end, ptr, spec);
1588 		}
1589 		break;
1590 	case 'a':
1591 		return address_val(buf, end, ptr, spec, fmt);
1592 	case 'd':
1593 		return dentry_name(buf, end, ptr, spec, fmt);
1594 	case 'C':
1595 		return clock(buf, end, ptr, spec, fmt);
1596 	case 'D':
1597 		return dentry_name(buf, end,
1598 				   ((const struct file *)ptr)->f_path.dentry,
1599 				   spec, fmt);
1600 	}
1601 	spec.flags |= SMALL;
1602 	if (spec.field_width == -1) {
1603 		spec.field_width = default_width;
1604 		spec.flags |= ZEROPAD;
1605 	}
1606 	spec.base = 16;
1607 
1608 	return number(buf, end, (unsigned long) ptr, spec);
1609 }
1610 
1611 /*
1612  * Helper function to decode printf style format.
1613  * Each call decode a token from the format and return the
1614  * number of characters read (or likely the delta where it wants
1615  * to go on the next call).
1616  * The decoded token is returned through the parameters
1617  *
1618  * 'h', 'l', or 'L' for integer fields
1619  * 'z' support added 23/7/1999 S.H.
1620  * 'z' changed to 'Z' --davidm 1/25/99
1621  * 't' added for ptrdiff_t
1622  *
1623  * @fmt: the format string
1624  * @type of the token returned
1625  * @flags: various flags such as +, -, # tokens..
1626  * @field_width: overwritten width
1627  * @base: base of the number (octal, hex, ...)
1628  * @precision: precision of a number
1629  * @qualifier: qualifier of a number (long, size_t, ...)
1630  */
1631 static noinline_for_stack
1632 int format_decode(const char *fmt, struct printf_spec *spec)
1633 {
1634 	const char *start = fmt;
1635 
1636 	/* we finished early by reading the field width */
1637 	if (spec->type == FORMAT_TYPE_WIDTH) {
1638 		if (spec->field_width < 0) {
1639 			spec->field_width = -spec->field_width;
1640 			spec->flags |= LEFT;
1641 		}
1642 		spec->type = FORMAT_TYPE_NONE;
1643 		goto precision;
1644 	}
1645 
1646 	/* we finished early by reading the precision */
1647 	if (spec->type == FORMAT_TYPE_PRECISION) {
1648 		if (spec->precision < 0)
1649 			spec->precision = 0;
1650 
1651 		spec->type = FORMAT_TYPE_NONE;
1652 		goto qualifier;
1653 	}
1654 
1655 	/* By default */
1656 	spec->type = FORMAT_TYPE_NONE;
1657 
1658 	for (; *fmt ; ++fmt) {
1659 		if (*fmt == '%')
1660 			break;
1661 	}
1662 
1663 	/* Return the current non-format string */
1664 	if (fmt != start || !*fmt)
1665 		return fmt - start;
1666 
1667 	/* Process flags */
1668 	spec->flags = 0;
1669 
1670 	while (1) { /* this also skips first '%' */
1671 		bool found = true;
1672 
1673 		++fmt;
1674 
1675 		switch (*fmt) {
1676 		case '-': spec->flags |= LEFT;    break;
1677 		case '+': spec->flags |= PLUS;    break;
1678 		case ' ': spec->flags |= SPACE;   break;
1679 		case '#': spec->flags |= SPECIAL; break;
1680 		case '0': spec->flags |= ZEROPAD; break;
1681 		default:  found = false;
1682 		}
1683 
1684 		if (!found)
1685 			break;
1686 	}
1687 
1688 	/* get field width */
1689 	spec->field_width = -1;
1690 
1691 	if (isdigit(*fmt))
1692 		spec->field_width = skip_atoi(&fmt);
1693 	else if (*fmt == '*') {
1694 		/* it's the next argument */
1695 		spec->type = FORMAT_TYPE_WIDTH;
1696 		return ++fmt - start;
1697 	}
1698 
1699 precision:
1700 	/* get the precision */
1701 	spec->precision = -1;
1702 	if (*fmt == '.') {
1703 		++fmt;
1704 		if (isdigit(*fmt)) {
1705 			spec->precision = skip_atoi(&fmt);
1706 			if (spec->precision < 0)
1707 				spec->precision = 0;
1708 		} else if (*fmt == '*') {
1709 			/* it's the next argument */
1710 			spec->type = FORMAT_TYPE_PRECISION;
1711 			return ++fmt - start;
1712 		}
1713 	}
1714 
1715 qualifier:
1716 	/* get the conversion qualifier */
1717 	spec->qualifier = -1;
1718 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1719 	    _tolower(*fmt) == 'z' || *fmt == 't') {
1720 		spec->qualifier = *fmt++;
1721 		if (unlikely(spec->qualifier == *fmt)) {
1722 			if (spec->qualifier == 'l') {
1723 				spec->qualifier = 'L';
1724 				++fmt;
1725 			} else if (spec->qualifier == 'h') {
1726 				spec->qualifier = 'H';
1727 				++fmt;
1728 			}
1729 		}
1730 	}
1731 
1732 	/* default base */
1733 	spec->base = 10;
1734 	switch (*fmt) {
1735 	case 'c':
1736 		spec->type = FORMAT_TYPE_CHAR;
1737 		return ++fmt - start;
1738 
1739 	case 's':
1740 		spec->type = FORMAT_TYPE_STR;
1741 		return ++fmt - start;
1742 
1743 	case 'p':
1744 		spec->type = FORMAT_TYPE_PTR;
1745 		return ++fmt - start;
1746 
1747 	case '%':
1748 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
1749 		return ++fmt - start;
1750 
1751 	/* integer number formats - set up the flags and "break" */
1752 	case 'o':
1753 		spec->base = 8;
1754 		break;
1755 
1756 	case 'x':
1757 		spec->flags |= SMALL;
1758 
1759 	case 'X':
1760 		spec->base = 16;
1761 		break;
1762 
1763 	case 'd':
1764 	case 'i':
1765 		spec->flags |= SIGN;
1766 	case 'u':
1767 		break;
1768 
1769 	case 'n':
1770 		/*
1771 		 * Since %n poses a greater security risk than utility, treat
1772 		 * it as an invalid format specifier. Warn about its use so
1773 		 * that new instances don't get added.
1774 		 */
1775 		WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1776 		/* Fall-through */
1777 
1778 	default:
1779 		spec->type = FORMAT_TYPE_INVALID;
1780 		return fmt - start;
1781 	}
1782 
1783 	if (spec->qualifier == 'L')
1784 		spec->type = FORMAT_TYPE_LONG_LONG;
1785 	else if (spec->qualifier == 'l') {
1786 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
1787 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
1788 	} else if (_tolower(spec->qualifier) == 'z') {
1789 		spec->type = FORMAT_TYPE_SIZE_T;
1790 	} else if (spec->qualifier == 't') {
1791 		spec->type = FORMAT_TYPE_PTRDIFF;
1792 	} else if (spec->qualifier == 'H') {
1793 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
1794 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
1795 	} else if (spec->qualifier == 'h') {
1796 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
1797 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
1798 	} else {
1799 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
1800 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
1801 	}
1802 
1803 	return ++fmt - start;
1804 }
1805 
1806 /**
1807  * vsnprintf - Format a string and place it in a buffer
1808  * @buf: The buffer to place the result into
1809  * @size: The size of the buffer, including the trailing null space
1810  * @fmt: The format string to use
1811  * @args: Arguments for the format string
1812  *
1813  * This function follows C99 vsnprintf, but has some extensions:
1814  * %pS output the name of a text symbol with offset
1815  * %ps output the name of a text symbol without offset
1816  * %pF output the name of a function pointer with its offset
1817  * %pf output the name of a function pointer without its offset
1818  * %pB output the name of a backtrace symbol with its offset
1819  * %pR output the address range in a struct resource with decoded flags
1820  * %pr output the address range in a struct resource with raw flags
1821  * %pb output the bitmap with field width as the number of bits
1822  * %pbl output the bitmap as range list with field width as the number of bits
1823  * %pM output a 6-byte MAC address with colons
1824  * %pMR output a 6-byte MAC address with colons in reversed order
1825  * %pMF output a 6-byte MAC address with dashes
1826  * %pm output a 6-byte MAC address without colons
1827  * %pmR output a 6-byte MAC address without colons in reversed order
1828  * %pI4 print an IPv4 address without leading zeros
1829  * %pi4 print an IPv4 address with leading zeros
1830  * %pI6 print an IPv6 address with colons
1831  * %pi6 print an IPv6 address without colons
1832  * %pI6c print an IPv6 address as specified by RFC 5952
1833  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1834  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1835  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1836  *   case.
1837  * %*pE[achnops] print an escaped buffer
1838  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1839  *           bytes of the input)
1840  * %pC output the name (Common Clock Framework) or address (legacy clock
1841  *     framework) of a clock
1842  * %pCn output the name (Common Clock Framework) or address (legacy clock
1843  *      framework) of a clock
1844  * %pCr output the current rate of a clock
1845  * %n is ignored
1846  *
1847  * ** Please update Documentation/printk-formats.txt when making changes **
1848  *
1849  * The return value is the number of characters which would
1850  * be generated for the given input, excluding the trailing
1851  * '\0', as per ISO C99. If you want to have the exact
1852  * number of characters written into @buf as return value
1853  * (not including the trailing '\0'), use vscnprintf(). If the
1854  * return is greater than or equal to @size, the resulting
1855  * string is truncated.
1856  *
1857  * If you're not already dealing with a va_list consider using snprintf().
1858  */
1859 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1860 {
1861 	unsigned long long num;
1862 	char *str, *end;
1863 	struct printf_spec spec = {0};
1864 
1865 	/* Reject out-of-range values early.  Large positive sizes are
1866 	   used for unknown buffer sizes. */
1867 	if (WARN_ON_ONCE(size > INT_MAX))
1868 		return 0;
1869 
1870 	str = buf;
1871 	end = buf + size;
1872 
1873 	/* Make sure end is always >= buf */
1874 	if (end < buf) {
1875 		end = ((void *)-1);
1876 		size = end - buf;
1877 	}
1878 
1879 	while (*fmt) {
1880 		const char *old_fmt = fmt;
1881 		int read = format_decode(fmt, &spec);
1882 
1883 		fmt += read;
1884 
1885 		switch (spec.type) {
1886 		case FORMAT_TYPE_NONE: {
1887 			int copy = read;
1888 			if (str < end) {
1889 				if (copy > end - str)
1890 					copy = end - str;
1891 				memcpy(str, old_fmt, copy);
1892 			}
1893 			str += read;
1894 			break;
1895 		}
1896 
1897 		case FORMAT_TYPE_WIDTH:
1898 			spec.field_width = va_arg(args, int);
1899 			break;
1900 
1901 		case FORMAT_TYPE_PRECISION:
1902 			spec.precision = va_arg(args, int);
1903 			break;
1904 
1905 		case FORMAT_TYPE_CHAR: {
1906 			char c;
1907 
1908 			if (!(spec.flags & LEFT)) {
1909 				while (--spec.field_width > 0) {
1910 					if (str < end)
1911 						*str = ' ';
1912 					++str;
1913 
1914 				}
1915 			}
1916 			c = (unsigned char) va_arg(args, int);
1917 			if (str < end)
1918 				*str = c;
1919 			++str;
1920 			while (--spec.field_width > 0) {
1921 				if (str < end)
1922 					*str = ' ';
1923 				++str;
1924 			}
1925 			break;
1926 		}
1927 
1928 		case FORMAT_TYPE_STR:
1929 			str = string(str, end, va_arg(args, char *), spec);
1930 			break;
1931 
1932 		case FORMAT_TYPE_PTR:
1933 			str = pointer(fmt, str, end, va_arg(args, void *),
1934 				      spec);
1935 			while (isalnum(*fmt))
1936 				fmt++;
1937 			break;
1938 
1939 		case FORMAT_TYPE_PERCENT_CHAR:
1940 			if (str < end)
1941 				*str = '%';
1942 			++str;
1943 			break;
1944 
1945 		case FORMAT_TYPE_INVALID:
1946 			if (str < end)
1947 				*str = '%';
1948 			++str;
1949 			break;
1950 
1951 		default:
1952 			switch (spec.type) {
1953 			case FORMAT_TYPE_LONG_LONG:
1954 				num = va_arg(args, long long);
1955 				break;
1956 			case FORMAT_TYPE_ULONG:
1957 				num = va_arg(args, unsigned long);
1958 				break;
1959 			case FORMAT_TYPE_LONG:
1960 				num = va_arg(args, long);
1961 				break;
1962 			case FORMAT_TYPE_SIZE_T:
1963 				if (spec.flags & SIGN)
1964 					num = va_arg(args, ssize_t);
1965 				else
1966 					num = va_arg(args, size_t);
1967 				break;
1968 			case FORMAT_TYPE_PTRDIFF:
1969 				num = va_arg(args, ptrdiff_t);
1970 				break;
1971 			case FORMAT_TYPE_UBYTE:
1972 				num = (unsigned char) va_arg(args, int);
1973 				break;
1974 			case FORMAT_TYPE_BYTE:
1975 				num = (signed char) va_arg(args, int);
1976 				break;
1977 			case FORMAT_TYPE_USHORT:
1978 				num = (unsigned short) va_arg(args, int);
1979 				break;
1980 			case FORMAT_TYPE_SHORT:
1981 				num = (short) va_arg(args, int);
1982 				break;
1983 			case FORMAT_TYPE_INT:
1984 				num = (int) va_arg(args, int);
1985 				break;
1986 			default:
1987 				num = va_arg(args, unsigned int);
1988 			}
1989 
1990 			str = number(str, end, num, spec);
1991 		}
1992 	}
1993 
1994 	if (size > 0) {
1995 		if (str < end)
1996 			*str = '\0';
1997 		else
1998 			end[-1] = '\0';
1999 	}
2000 
2001 	/* the trailing null byte doesn't count towards the total */
2002 	return str-buf;
2003 
2004 }
2005 EXPORT_SYMBOL(vsnprintf);
2006 
2007 /**
2008  * vscnprintf - Format a string and place it in a buffer
2009  * @buf: The buffer to place the result into
2010  * @size: The size of the buffer, including the trailing null space
2011  * @fmt: The format string to use
2012  * @args: Arguments for the format string
2013  *
2014  * The return value is the number of characters which have been written into
2015  * the @buf not including the trailing '\0'. If @size is == 0 the function
2016  * returns 0.
2017  *
2018  * If you're not already dealing with a va_list consider using scnprintf().
2019  *
2020  * See the vsnprintf() documentation for format string extensions over C99.
2021  */
2022 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2023 {
2024 	int i;
2025 
2026 	i = vsnprintf(buf, size, fmt, args);
2027 
2028 	if (likely(i < size))
2029 		return i;
2030 	if (size != 0)
2031 		return size - 1;
2032 	return 0;
2033 }
2034 EXPORT_SYMBOL(vscnprintf);
2035 
2036 /**
2037  * snprintf - Format a string and place it in a buffer
2038  * @buf: The buffer to place the result into
2039  * @size: The size of the buffer, including the trailing null space
2040  * @fmt: The format string to use
2041  * @...: Arguments for the format string
2042  *
2043  * The return value is the number of characters which would be
2044  * generated for the given input, excluding the trailing null,
2045  * as per ISO C99.  If the return is greater than or equal to
2046  * @size, the resulting string is truncated.
2047  *
2048  * See the vsnprintf() documentation for format string extensions over C99.
2049  */
2050 int snprintf(char *buf, size_t size, const char *fmt, ...)
2051 {
2052 	va_list args;
2053 	int i;
2054 
2055 	va_start(args, fmt);
2056 	i = vsnprintf(buf, size, fmt, args);
2057 	va_end(args);
2058 
2059 	return i;
2060 }
2061 EXPORT_SYMBOL(snprintf);
2062 
2063 /**
2064  * scnprintf - Format a string and place it in a buffer
2065  * @buf: The buffer to place the result into
2066  * @size: The size of the buffer, including the trailing null space
2067  * @fmt: The format string to use
2068  * @...: Arguments for the format string
2069  *
2070  * The return value is the number of characters written into @buf not including
2071  * the trailing '\0'. If @size is == 0 the function returns 0.
2072  */
2073 
2074 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2075 {
2076 	va_list args;
2077 	int i;
2078 
2079 	va_start(args, fmt);
2080 	i = vscnprintf(buf, size, fmt, args);
2081 	va_end(args);
2082 
2083 	return i;
2084 }
2085 EXPORT_SYMBOL(scnprintf);
2086 
2087 /**
2088  * vsprintf - Format a string and place it in a buffer
2089  * @buf: The buffer to place the result into
2090  * @fmt: The format string to use
2091  * @args: Arguments for the format string
2092  *
2093  * The function returns the number of characters written
2094  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2095  * buffer overflows.
2096  *
2097  * If you're not already dealing with a va_list consider using sprintf().
2098  *
2099  * See the vsnprintf() documentation for format string extensions over C99.
2100  */
2101 int vsprintf(char *buf, const char *fmt, va_list args)
2102 {
2103 	return vsnprintf(buf, INT_MAX, fmt, args);
2104 }
2105 EXPORT_SYMBOL(vsprintf);
2106 
2107 /**
2108  * sprintf - Format a string and place it in a buffer
2109  * @buf: The buffer to place the result into
2110  * @fmt: The format string to use
2111  * @...: Arguments for the format string
2112  *
2113  * The function returns the number of characters written
2114  * into @buf. Use snprintf() or scnprintf() in order to avoid
2115  * buffer overflows.
2116  *
2117  * See the vsnprintf() documentation for format string extensions over C99.
2118  */
2119 int sprintf(char *buf, const char *fmt, ...)
2120 {
2121 	va_list args;
2122 	int i;
2123 
2124 	va_start(args, fmt);
2125 	i = vsnprintf(buf, INT_MAX, fmt, args);
2126 	va_end(args);
2127 
2128 	return i;
2129 }
2130 EXPORT_SYMBOL(sprintf);
2131 
2132 #ifdef CONFIG_BINARY_PRINTF
2133 /*
2134  * bprintf service:
2135  * vbin_printf() - VA arguments to binary data
2136  * bstr_printf() - Binary data to text string
2137  */
2138 
2139 /**
2140  * vbin_printf - Parse a format string and place args' binary value in a buffer
2141  * @bin_buf: The buffer to place args' binary value
2142  * @size: The size of the buffer(by words(32bits), not characters)
2143  * @fmt: The format string to use
2144  * @args: Arguments for the format string
2145  *
2146  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2147  * is skipped.
2148  *
2149  * The return value is the number of words(32bits) which would be generated for
2150  * the given input.
2151  *
2152  * NOTE:
2153  * If the return value is greater than @size, the resulting bin_buf is NOT
2154  * valid for bstr_printf().
2155  */
2156 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2157 {
2158 	struct printf_spec spec = {0};
2159 	char *str, *end;
2160 
2161 	str = (char *)bin_buf;
2162 	end = (char *)(bin_buf + size);
2163 
2164 #define save_arg(type)							\
2165 do {									\
2166 	if (sizeof(type) == 8) {					\
2167 		unsigned long long value;				\
2168 		str = PTR_ALIGN(str, sizeof(u32));			\
2169 		value = va_arg(args, unsigned long long);		\
2170 		if (str + sizeof(type) <= end) {			\
2171 			*(u32 *)str = *(u32 *)&value;			\
2172 			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
2173 		}							\
2174 	} else {							\
2175 		unsigned long value;					\
2176 		str = PTR_ALIGN(str, sizeof(type));			\
2177 		value = va_arg(args, int);				\
2178 		if (str + sizeof(type) <= end)				\
2179 			*(typeof(type) *)str = (type)value;		\
2180 	}								\
2181 	str += sizeof(type);						\
2182 } while (0)
2183 
2184 	while (*fmt) {
2185 		int read = format_decode(fmt, &spec);
2186 
2187 		fmt += read;
2188 
2189 		switch (spec.type) {
2190 		case FORMAT_TYPE_NONE:
2191 		case FORMAT_TYPE_INVALID:
2192 		case FORMAT_TYPE_PERCENT_CHAR:
2193 			break;
2194 
2195 		case FORMAT_TYPE_WIDTH:
2196 		case FORMAT_TYPE_PRECISION:
2197 			save_arg(int);
2198 			break;
2199 
2200 		case FORMAT_TYPE_CHAR:
2201 			save_arg(char);
2202 			break;
2203 
2204 		case FORMAT_TYPE_STR: {
2205 			const char *save_str = va_arg(args, char *);
2206 			size_t len;
2207 
2208 			if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2209 					|| (unsigned long)save_str < PAGE_SIZE)
2210 				save_str = "(null)";
2211 			len = strlen(save_str) + 1;
2212 			if (str + len < end)
2213 				memcpy(str, save_str, len);
2214 			str += len;
2215 			break;
2216 		}
2217 
2218 		case FORMAT_TYPE_PTR:
2219 			save_arg(void *);
2220 			/* skip all alphanumeric pointer suffixes */
2221 			while (isalnum(*fmt))
2222 				fmt++;
2223 			break;
2224 
2225 		default:
2226 			switch (spec.type) {
2227 
2228 			case FORMAT_TYPE_LONG_LONG:
2229 				save_arg(long long);
2230 				break;
2231 			case FORMAT_TYPE_ULONG:
2232 			case FORMAT_TYPE_LONG:
2233 				save_arg(unsigned long);
2234 				break;
2235 			case FORMAT_TYPE_SIZE_T:
2236 				save_arg(size_t);
2237 				break;
2238 			case FORMAT_TYPE_PTRDIFF:
2239 				save_arg(ptrdiff_t);
2240 				break;
2241 			case FORMAT_TYPE_UBYTE:
2242 			case FORMAT_TYPE_BYTE:
2243 				save_arg(char);
2244 				break;
2245 			case FORMAT_TYPE_USHORT:
2246 			case FORMAT_TYPE_SHORT:
2247 				save_arg(short);
2248 				break;
2249 			default:
2250 				save_arg(int);
2251 			}
2252 		}
2253 	}
2254 
2255 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2256 #undef save_arg
2257 }
2258 EXPORT_SYMBOL_GPL(vbin_printf);
2259 
2260 /**
2261  * bstr_printf - Format a string from binary arguments and place it in a buffer
2262  * @buf: The buffer to place the result into
2263  * @size: The size of the buffer, including the trailing null space
2264  * @fmt: The format string to use
2265  * @bin_buf: Binary arguments for the format string
2266  *
2267  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2268  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2269  * a binary buffer that generated by vbin_printf.
2270  *
2271  * The format follows C99 vsnprintf, but has some extensions:
2272  *  see vsnprintf comment for details.
2273  *
2274  * The return value is the number of characters which would
2275  * be generated for the given input, excluding the trailing
2276  * '\0', as per ISO C99. If you want to have the exact
2277  * number of characters written into @buf as return value
2278  * (not including the trailing '\0'), use vscnprintf(). If the
2279  * return is greater than or equal to @size, the resulting
2280  * string is truncated.
2281  */
2282 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2283 {
2284 	struct printf_spec spec = {0};
2285 	char *str, *end;
2286 	const char *args = (const char *)bin_buf;
2287 
2288 	if (WARN_ON_ONCE((int) size < 0))
2289 		return 0;
2290 
2291 	str = buf;
2292 	end = buf + size;
2293 
2294 #define get_arg(type)							\
2295 ({									\
2296 	typeof(type) value;						\
2297 	if (sizeof(type) == 8) {					\
2298 		args = PTR_ALIGN(args, sizeof(u32));			\
2299 		*(u32 *)&value = *(u32 *)args;				\
2300 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
2301 	} else {							\
2302 		args = PTR_ALIGN(args, sizeof(type));			\
2303 		value = *(typeof(type) *)args;				\
2304 	}								\
2305 	args += sizeof(type);						\
2306 	value;								\
2307 })
2308 
2309 	/* Make sure end is always >= buf */
2310 	if (end < buf) {
2311 		end = ((void *)-1);
2312 		size = end - buf;
2313 	}
2314 
2315 	while (*fmt) {
2316 		const char *old_fmt = fmt;
2317 		int read = format_decode(fmt, &spec);
2318 
2319 		fmt += read;
2320 
2321 		switch (spec.type) {
2322 		case FORMAT_TYPE_NONE: {
2323 			int copy = read;
2324 			if (str < end) {
2325 				if (copy > end - str)
2326 					copy = end - str;
2327 				memcpy(str, old_fmt, copy);
2328 			}
2329 			str += read;
2330 			break;
2331 		}
2332 
2333 		case FORMAT_TYPE_WIDTH:
2334 			spec.field_width = get_arg(int);
2335 			break;
2336 
2337 		case FORMAT_TYPE_PRECISION:
2338 			spec.precision = get_arg(int);
2339 			break;
2340 
2341 		case FORMAT_TYPE_CHAR: {
2342 			char c;
2343 
2344 			if (!(spec.flags & LEFT)) {
2345 				while (--spec.field_width > 0) {
2346 					if (str < end)
2347 						*str = ' ';
2348 					++str;
2349 				}
2350 			}
2351 			c = (unsigned char) get_arg(char);
2352 			if (str < end)
2353 				*str = c;
2354 			++str;
2355 			while (--spec.field_width > 0) {
2356 				if (str < end)
2357 					*str = ' ';
2358 				++str;
2359 			}
2360 			break;
2361 		}
2362 
2363 		case FORMAT_TYPE_STR: {
2364 			const char *str_arg = args;
2365 			args += strlen(str_arg) + 1;
2366 			str = string(str, end, (char *)str_arg, spec);
2367 			break;
2368 		}
2369 
2370 		case FORMAT_TYPE_PTR:
2371 			str = pointer(fmt, str, end, get_arg(void *), spec);
2372 			while (isalnum(*fmt))
2373 				fmt++;
2374 			break;
2375 
2376 		case FORMAT_TYPE_PERCENT_CHAR:
2377 		case FORMAT_TYPE_INVALID:
2378 			if (str < end)
2379 				*str = '%';
2380 			++str;
2381 			break;
2382 
2383 		default: {
2384 			unsigned long long num;
2385 
2386 			switch (spec.type) {
2387 
2388 			case FORMAT_TYPE_LONG_LONG:
2389 				num = get_arg(long long);
2390 				break;
2391 			case FORMAT_TYPE_ULONG:
2392 			case FORMAT_TYPE_LONG:
2393 				num = get_arg(unsigned long);
2394 				break;
2395 			case FORMAT_TYPE_SIZE_T:
2396 				num = get_arg(size_t);
2397 				break;
2398 			case FORMAT_TYPE_PTRDIFF:
2399 				num = get_arg(ptrdiff_t);
2400 				break;
2401 			case FORMAT_TYPE_UBYTE:
2402 				num = get_arg(unsigned char);
2403 				break;
2404 			case FORMAT_TYPE_BYTE:
2405 				num = get_arg(signed char);
2406 				break;
2407 			case FORMAT_TYPE_USHORT:
2408 				num = get_arg(unsigned short);
2409 				break;
2410 			case FORMAT_TYPE_SHORT:
2411 				num = get_arg(short);
2412 				break;
2413 			case FORMAT_TYPE_UINT:
2414 				num = get_arg(unsigned int);
2415 				break;
2416 			default:
2417 				num = get_arg(int);
2418 			}
2419 
2420 			str = number(str, end, num, spec);
2421 		} /* default: */
2422 		} /* switch(spec.type) */
2423 	} /* while(*fmt) */
2424 
2425 	if (size > 0) {
2426 		if (str < end)
2427 			*str = '\0';
2428 		else
2429 			end[-1] = '\0';
2430 	}
2431 
2432 #undef get_arg
2433 
2434 	/* the trailing null byte doesn't count towards the total */
2435 	return str - buf;
2436 }
2437 EXPORT_SYMBOL_GPL(bstr_printf);
2438 
2439 /**
2440  * bprintf - Parse a format string and place args' binary value in a buffer
2441  * @bin_buf: The buffer to place args' binary value
2442  * @size: The size of the buffer(by words(32bits), not characters)
2443  * @fmt: The format string to use
2444  * @...: Arguments for the format string
2445  *
2446  * The function returns the number of words(u32) written
2447  * into @bin_buf.
2448  */
2449 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2450 {
2451 	va_list args;
2452 	int ret;
2453 
2454 	va_start(args, fmt);
2455 	ret = vbin_printf(bin_buf, size, fmt, args);
2456 	va_end(args);
2457 
2458 	return ret;
2459 }
2460 EXPORT_SYMBOL_GPL(bprintf);
2461 
2462 #endif /* CONFIG_BINARY_PRINTF */
2463 
2464 /**
2465  * vsscanf - Unformat a buffer into a list of arguments
2466  * @buf:	input buffer
2467  * @fmt:	format of buffer
2468  * @args:	arguments
2469  */
2470 int vsscanf(const char *buf, const char *fmt, va_list args)
2471 {
2472 	const char *str = buf;
2473 	char *next;
2474 	char digit;
2475 	int num = 0;
2476 	u8 qualifier;
2477 	unsigned int base;
2478 	union {
2479 		long long s;
2480 		unsigned long long u;
2481 	} val;
2482 	s16 field_width;
2483 	bool is_sign;
2484 
2485 	while (*fmt) {
2486 		/* skip any white space in format */
2487 		/* white space in format matchs any amount of
2488 		 * white space, including none, in the input.
2489 		 */
2490 		if (isspace(*fmt)) {
2491 			fmt = skip_spaces(++fmt);
2492 			str = skip_spaces(str);
2493 		}
2494 
2495 		/* anything that is not a conversion must match exactly */
2496 		if (*fmt != '%' && *fmt) {
2497 			if (*fmt++ != *str++)
2498 				break;
2499 			continue;
2500 		}
2501 
2502 		if (!*fmt)
2503 			break;
2504 		++fmt;
2505 
2506 		/* skip this conversion.
2507 		 * advance both strings to next white space
2508 		 */
2509 		if (*fmt == '*') {
2510 			if (!*str)
2511 				break;
2512 			while (!isspace(*fmt) && *fmt != '%' && *fmt)
2513 				fmt++;
2514 			while (!isspace(*str) && *str)
2515 				str++;
2516 			continue;
2517 		}
2518 
2519 		/* get field width */
2520 		field_width = -1;
2521 		if (isdigit(*fmt)) {
2522 			field_width = skip_atoi(&fmt);
2523 			if (field_width <= 0)
2524 				break;
2525 		}
2526 
2527 		/* get conversion qualifier */
2528 		qualifier = -1;
2529 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2530 		    _tolower(*fmt) == 'z') {
2531 			qualifier = *fmt++;
2532 			if (unlikely(qualifier == *fmt)) {
2533 				if (qualifier == 'h') {
2534 					qualifier = 'H';
2535 					fmt++;
2536 				} else if (qualifier == 'l') {
2537 					qualifier = 'L';
2538 					fmt++;
2539 				}
2540 			}
2541 		}
2542 
2543 		if (!*fmt)
2544 			break;
2545 
2546 		if (*fmt == 'n') {
2547 			/* return number of characters read so far */
2548 			*va_arg(args, int *) = str - buf;
2549 			++fmt;
2550 			continue;
2551 		}
2552 
2553 		if (!*str)
2554 			break;
2555 
2556 		base = 10;
2557 		is_sign = false;
2558 
2559 		switch (*fmt++) {
2560 		case 'c':
2561 		{
2562 			char *s = (char *)va_arg(args, char*);
2563 			if (field_width == -1)
2564 				field_width = 1;
2565 			do {
2566 				*s++ = *str++;
2567 			} while (--field_width > 0 && *str);
2568 			num++;
2569 		}
2570 		continue;
2571 		case 's':
2572 		{
2573 			char *s = (char *)va_arg(args, char *);
2574 			if (field_width == -1)
2575 				field_width = SHRT_MAX;
2576 			/* first, skip leading white space in buffer */
2577 			str = skip_spaces(str);
2578 
2579 			/* now copy until next white space */
2580 			while (*str && !isspace(*str) && field_width--)
2581 				*s++ = *str++;
2582 			*s = '\0';
2583 			num++;
2584 		}
2585 		continue;
2586 		case 'o':
2587 			base = 8;
2588 			break;
2589 		case 'x':
2590 		case 'X':
2591 			base = 16;
2592 			break;
2593 		case 'i':
2594 			base = 0;
2595 		case 'd':
2596 			is_sign = true;
2597 		case 'u':
2598 			break;
2599 		case '%':
2600 			/* looking for '%' in str */
2601 			if (*str++ != '%')
2602 				return num;
2603 			continue;
2604 		default:
2605 			/* invalid format; stop here */
2606 			return num;
2607 		}
2608 
2609 		/* have some sort of integer conversion.
2610 		 * first, skip white space in buffer.
2611 		 */
2612 		str = skip_spaces(str);
2613 
2614 		digit = *str;
2615 		if (is_sign && digit == '-')
2616 			digit = *(str + 1);
2617 
2618 		if (!digit
2619 		    || (base == 16 && !isxdigit(digit))
2620 		    || (base == 10 && !isdigit(digit))
2621 		    || (base == 8 && (!isdigit(digit) || digit > '7'))
2622 		    || (base == 0 && !isdigit(digit)))
2623 			break;
2624 
2625 		if (is_sign)
2626 			val.s = qualifier != 'L' ?
2627 				simple_strtol(str, &next, base) :
2628 				simple_strtoll(str, &next, base);
2629 		else
2630 			val.u = qualifier != 'L' ?
2631 				simple_strtoul(str, &next, base) :
2632 				simple_strtoull(str, &next, base);
2633 
2634 		if (field_width > 0 && next - str > field_width) {
2635 			if (base == 0)
2636 				_parse_integer_fixup_radix(str, &base);
2637 			while (next - str > field_width) {
2638 				if (is_sign)
2639 					val.s = div_s64(val.s, base);
2640 				else
2641 					val.u = div_u64(val.u, base);
2642 				--next;
2643 			}
2644 		}
2645 
2646 		switch (qualifier) {
2647 		case 'H':	/* that's 'hh' in format */
2648 			if (is_sign)
2649 				*va_arg(args, signed char *) = val.s;
2650 			else
2651 				*va_arg(args, unsigned char *) = val.u;
2652 			break;
2653 		case 'h':
2654 			if (is_sign)
2655 				*va_arg(args, short *) = val.s;
2656 			else
2657 				*va_arg(args, unsigned short *) = val.u;
2658 			break;
2659 		case 'l':
2660 			if (is_sign)
2661 				*va_arg(args, long *) = val.s;
2662 			else
2663 				*va_arg(args, unsigned long *) = val.u;
2664 			break;
2665 		case 'L':
2666 			if (is_sign)
2667 				*va_arg(args, long long *) = val.s;
2668 			else
2669 				*va_arg(args, unsigned long long *) = val.u;
2670 			break;
2671 		case 'Z':
2672 		case 'z':
2673 			*va_arg(args, size_t *) = val.u;
2674 			break;
2675 		default:
2676 			if (is_sign)
2677 				*va_arg(args, int *) = val.s;
2678 			else
2679 				*va_arg(args, unsigned int *) = val.u;
2680 			break;
2681 		}
2682 		num++;
2683 
2684 		if (!next)
2685 			break;
2686 		str = next;
2687 	}
2688 
2689 	return num;
2690 }
2691 EXPORT_SYMBOL(vsscanf);
2692 
2693 /**
2694  * sscanf - Unformat a buffer into a list of arguments
2695  * @buf:	input buffer
2696  * @fmt:	formatting of buffer
2697  * @...:	resulting arguments
2698  */
2699 int sscanf(const char *buf, const char *fmt, ...)
2700 {
2701 	va_list args;
2702 	int i;
2703 
2704 	va_start(args, fmt);
2705 	i = vsscanf(buf, fmt, args);
2706 	va_end(args);
2707 
2708 	return i;
2709 }
2710 EXPORT_SYMBOL(sscanf);
2711