xref: /linux/lib/vsprintf.c (revision 7ec462100ef9142344ddbf86f2c3008b97acddbe)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/lib/vsprintf.c
4  *
5  *  Copyright (C) 1991, 1992  Linus Torvalds
6  */
7 
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10  * Wirzenius wrote this portably, Torvalds fucked it up :-)
11  */
12 
13 /*
14  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15  * - changed to provide snprintf and vsnprintf functions
16  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17  * - scnprintf and vscnprintf
18  */
19 
20 #include <linux/stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h>	/* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/sprintf.h>
38 #include <linux/time.h>
39 #include <linux/uuid.h>
40 #include <linux/of.h>
41 #include <net/addrconf.h>
42 #include <linux/siphash.h>
43 #include <linux/compiler.h>
44 #include <linux/property.h>
45 #include <linux/notifier.h>
46 #ifdef CONFIG_BLOCK
47 #include <linux/blkdev.h>
48 #endif
49 
50 #include "../mm/internal.h"	/* For the trace_print_flags arrays */
51 
52 #include <asm/page.h>		/* for PAGE_SIZE */
53 #include <asm/byteorder.h>	/* cpu_to_le16 */
54 #include <linux/unaligned.h>
55 
56 #include <linux/string_helpers.h>
57 #include "kstrtox.h"
58 
59 /* Disable pointer hashing if requested */
60 bool no_hash_pointers __ro_after_init;
61 EXPORT_SYMBOL_GPL(no_hash_pointers);
62 
63 noinline
simple_strntoull(const char * startp,char ** endp,unsigned int base,size_t max_chars)64 static unsigned long long simple_strntoull(const char *startp, char **endp, unsigned int base, size_t max_chars)
65 {
66 	const char *cp;
67 	unsigned long long result = 0ULL;
68 	size_t prefix_chars;
69 	unsigned int rv;
70 
71 	cp = _parse_integer_fixup_radix(startp, &base);
72 	prefix_chars = cp - startp;
73 	if (prefix_chars < max_chars) {
74 		rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
75 		/* FIXME */
76 		cp += (rv & ~KSTRTOX_OVERFLOW);
77 	} else {
78 		/* Field too short for prefix + digit, skip over without converting */
79 		cp = startp + max_chars;
80 	}
81 
82 	if (endp)
83 		*endp = (char *)cp;
84 
85 	return result;
86 }
87 
88 /**
89  * simple_strtoull - convert a string to an unsigned long long
90  * @cp: The start of the string
91  * @endp: A pointer to the end of the parsed string will be placed here
92  * @base: The number base to use
93  *
94  * This function has caveats. Please use kstrtoull instead.
95  */
96 noinline
simple_strtoull(const char * cp,char ** endp,unsigned int base)97 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
98 {
99 	return simple_strntoull(cp, endp, base, INT_MAX);
100 }
101 EXPORT_SYMBOL(simple_strtoull);
102 
103 /**
104  * simple_strtoul - convert a string to an unsigned long
105  * @cp: The start of the string
106  * @endp: A pointer to the end of the parsed string will be placed here
107  * @base: The number base to use
108  *
109  * This function has caveats. Please use kstrtoul instead.
110  */
simple_strtoul(const char * cp,char ** endp,unsigned int base)111 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
112 {
113 	return simple_strtoull(cp, endp, base);
114 }
115 EXPORT_SYMBOL(simple_strtoul);
116 
117 /**
118  * simple_strtol - convert a string to a signed long
119  * @cp: The start of the string
120  * @endp: A pointer to the end of the parsed string will be placed here
121  * @base: The number base to use
122  *
123  * This function has caveats. Please use kstrtol instead.
124  */
simple_strtol(const char * cp,char ** endp,unsigned int base)125 long simple_strtol(const char *cp, char **endp, unsigned int base)
126 {
127 	if (*cp == '-')
128 		return -simple_strtoul(cp + 1, endp, base);
129 
130 	return simple_strtoul(cp, endp, base);
131 }
132 EXPORT_SYMBOL(simple_strtol);
133 
134 noinline
simple_strntoll(const char * cp,char ** endp,unsigned int base,size_t max_chars)135 static long long simple_strntoll(const char *cp, char **endp, unsigned int base, size_t max_chars)
136 {
137 	/*
138 	 * simple_strntoull() safely handles receiving max_chars==0 in the
139 	 * case cp[0] == '-' && max_chars == 1.
140 	 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
141 	 * and the content of *cp is irrelevant.
142 	 */
143 	if (*cp == '-' && max_chars > 0)
144 		return -simple_strntoull(cp + 1, endp, base, max_chars - 1);
145 
146 	return simple_strntoull(cp, endp, base, max_chars);
147 }
148 
149 /**
150  * simple_strtoll - convert a string to a signed long long
151  * @cp: The start of the string
152  * @endp: A pointer to the end of the parsed string will be placed here
153  * @base: The number base to use
154  *
155  * This function has caveats. Please use kstrtoll instead.
156  */
simple_strtoll(const char * cp,char ** endp,unsigned int base)157 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
158 {
159 	return simple_strntoll(cp, endp, base, INT_MAX);
160 }
161 EXPORT_SYMBOL(simple_strtoll);
162 
163 static noinline_for_stack
skip_atoi(const char ** s)164 int skip_atoi(const char **s)
165 {
166 	int i = 0;
167 
168 	do {
169 		i = i*10 + *((*s)++) - '0';
170 	} while (isdigit(**s));
171 
172 	return i;
173 }
174 
175 /*
176  * Decimal conversion is by far the most typical, and is used for
177  * /proc and /sys data. This directly impacts e.g. top performance
178  * with many processes running. We optimize it for speed by emitting
179  * two characters at a time, using a 200 byte lookup table. This
180  * roughly halves the number of multiplications compared to computing
181  * the digits one at a time. Implementation strongly inspired by the
182  * previous version, which in turn used ideas described at
183  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
184  * from the author, Douglas W. Jones).
185  *
186  * It turns out there is precisely one 26 bit fixed-point
187  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
188  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
189  * range happens to be somewhat larger (x <= 1073741898), but that's
190  * irrelevant for our purpose.
191  *
192  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
193  * need a 32x32->64 bit multiply, so we simply use the same constant.
194  *
195  * For dividing a number in the range [100, 10^4-1] by 100, there are
196  * several options. The simplest is (x * 0x147b) >> 19, which is valid
197  * for all x <= 43698.
198  */
199 
200 static const u16 decpair[100] = {
201 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
202 	_( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
203 	_(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
204 	_(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
205 	_(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
206 	_(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
207 	_(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
208 	_(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
209 	_(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
210 	_(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
211 	_(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
212 #undef _
213 };
214 
215 /*
216  * This will print a single '0' even if r == 0, since we would
217  * immediately jump to out_r where two 0s would be written but only
218  * one of them accounted for in buf. This is needed by ip4_string
219  * below. All other callers pass a non-zero value of r.
220 */
221 static noinline_for_stack
put_dec_trunc8(char * buf,unsigned r)222 char *put_dec_trunc8(char *buf, unsigned r)
223 {
224 	unsigned q;
225 
226 	/* 1 <= r < 10^8 */
227 	if (r < 100)
228 		goto out_r;
229 
230 	/* 100 <= r < 10^8 */
231 	q = (r * (u64)0x28f5c29) >> 32;
232 	*((u16 *)buf) = decpair[r - 100*q];
233 	buf += 2;
234 
235 	/* 1 <= q < 10^6 */
236 	if (q < 100)
237 		goto out_q;
238 
239 	/*  100 <= q < 10^6 */
240 	r = (q * (u64)0x28f5c29) >> 32;
241 	*((u16 *)buf) = decpair[q - 100*r];
242 	buf += 2;
243 
244 	/* 1 <= r < 10^4 */
245 	if (r < 100)
246 		goto out_r;
247 
248 	/* 100 <= r < 10^4 */
249 	q = (r * 0x147b) >> 19;
250 	*((u16 *)buf) = decpair[r - 100*q];
251 	buf += 2;
252 out_q:
253 	/* 1 <= q < 100 */
254 	r = q;
255 out_r:
256 	/* 1 <= r < 100 */
257 	*((u16 *)buf) = decpair[r];
258 	buf += r < 10 ? 1 : 2;
259 	return buf;
260 }
261 
262 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
263 static noinline_for_stack
put_dec_full8(char * buf,unsigned r)264 char *put_dec_full8(char *buf, unsigned r)
265 {
266 	unsigned q;
267 
268 	/* 0 <= r < 10^8 */
269 	q = (r * (u64)0x28f5c29) >> 32;
270 	*((u16 *)buf) = decpair[r - 100*q];
271 	buf += 2;
272 
273 	/* 0 <= q < 10^6 */
274 	r = (q * (u64)0x28f5c29) >> 32;
275 	*((u16 *)buf) = decpair[q - 100*r];
276 	buf += 2;
277 
278 	/* 0 <= r < 10^4 */
279 	q = (r * 0x147b) >> 19;
280 	*((u16 *)buf) = decpair[r - 100*q];
281 	buf += 2;
282 
283 	/* 0 <= q < 100 */
284 	*((u16 *)buf) = decpair[q];
285 	buf += 2;
286 	return buf;
287 }
288 
289 static noinline_for_stack
put_dec(char * buf,unsigned long long n)290 char *put_dec(char *buf, unsigned long long n)
291 {
292 	if (n >= 100*1000*1000)
293 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
294 	/* 1 <= n <= 1.6e11 */
295 	if (n >= 100*1000*1000)
296 		buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
297 	/* 1 <= n < 1e8 */
298 	return put_dec_trunc8(buf, n);
299 }
300 
301 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
302 
303 static void
put_dec_full4(char * buf,unsigned r)304 put_dec_full4(char *buf, unsigned r)
305 {
306 	unsigned q;
307 
308 	/* 0 <= r < 10^4 */
309 	q = (r * 0x147b) >> 19;
310 	*((u16 *)buf) = decpair[r - 100*q];
311 	buf += 2;
312 	/* 0 <= q < 100 */
313 	*((u16 *)buf) = decpair[q];
314 }
315 
316 /*
317  * Call put_dec_full4 on x % 10000, return x / 10000.
318  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
319  * holds for all x < 1,128,869,999.  The largest value this
320  * helper will ever be asked to convert is 1,125,520,955.
321  * (second call in the put_dec code, assuming n is all-ones).
322  */
323 static noinline_for_stack
put_dec_helper4(char * buf,unsigned x)324 unsigned put_dec_helper4(char *buf, unsigned x)
325 {
326         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
327 
328         put_dec_full4(buf, x - q * 10000);
329         return q;
330 }
331 
332 /* Based on code by Douglas W. Jones found at
333  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
334  * (with permission from the author).
335  * Performs no 64-bit division and hence should be fast on 32-bit machines.
336  */
337 static
put_dec(char * buf,unsigned long long n)338 char *put_dec(char *buf, unsigned long long n)
339 {
340 	uint32_t d3, d2, d1, q, h;
341 
342 	if (n < 100*1000*1000)
343 		return put_dec_trunc8(buf, n);
344 
345 	d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
346 	h   = (n >> 32);
347 	d2  = (h      ) & 0xffff;
348 	d3  = (h >> 16); /* implicit "& 0xffff" */
349 
350 	/* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
351 	     = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
352 	q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
353 	q = put_dec_helper4(buf, q);
354 
355 	q += 7671 * d3 + 9496 * d2 + 6 * d1;
356 	q = put_dec_helper4(buf+4, q);
357 
358 	q += 4749 * d3 + 42 * d2;
359 	q = put_dec_helper4(buf+8, q);
360 
361 	q += 281 * d3;
362 	buf += 12;
363 	if (q)
364 		buf = put_dec_trunc8(buf, q);
365 	else while (buf[-1] == '0')
366 		--buf;
367 
368 	return buf;
369 }
370 
371 #endif
372 
373 /*
374  * Convert passed number to decimal string.
375  * Returns the length of string.  On buffer overflow, returns 0.
376  *
377  * If speed is not important, use snprintf(). It's easy to read the code.
378  */
num_to_str(char * buf,int size,unsigned long long num,unsigned int width)379 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
380 {
381 	/* put_dec requires 2-byte alignment of the buffer. */
382 	char tmp[sizeof(num) * 3] __aligned(2);
383 	int idx, len;
384 
385 	/* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
386 	if (num <= 9) {
387 		tmp[0] = '0' + num;
388 		len = 1;
389 	} else {
390 		len = put_dec(tmp, num) - tmp;
391 	}
392 
393 	if (len > size || width > size)
394 		return 0;
395 
396 	if (width > len) {
397 		width = width - len;
398 		for (idx = 0; idx < width; idx++)
399 			buf[idx] = ' ';
400 	} else {
401 		width = 0;
402 	}
403 
404 	for (idx = 0; idx < len; ++idx)
405 		buf[idx + width] = tmp[len - idx - 1];
406 
407 	return len + width;
408 }
409 
410 #define SIGN	1		/* unsigned/signed, must be 1 */
411 #define LEFT	2		/* left justified */
412 #define PLUS	4		/* show plus */
413 #define SPACE	8		/* space if plus */
414 #define ZEROPAD	16		/* pad with zero, must be 16 == '0' - ' ' */
415 #define SMALL	32		/* use lowercase in hex (must be 32 == 0x20) */
416 #define SPECIAL	64		/* prefix hex with "0x", octal with "0" */
417 
418 static_assert(SIGN == 1);
419 static_assert(ZEROPAD == ('0' - ' '));
420 static_assert(SMALL == ('a' ^ 'A'));
421 
422 enum format_type {
423 	FORMAT_TYPE_NONE, /* Just a string part */
424 	FORMAT_TYPE_WIDTH,
425 	FORMAT_TYPE_PRECISION,
426 	FORMAT_TYPE_CHAR,
427 	FORMAT_TYPE_STR,
428 	FORMAT_TYPE_PTR,
429 	FORMAT_TYPE_PERCENT_CHAR,
430 	FORMAT_TYPE_INVALID,
431 	FORMAT_TYPE_LONG_LONG,
432 	FORMAT_TYPE_ULONG,
433 	FORMAT_TYPE_LONG,
434 	FORMAT_TYPE_UBYTE,
435 	FORMAT_TYPE_BYTE,
436 	FORMAT_TYPE_USHORT,
437 	FORMAT_TYPE_SHORT,
438 	FORMAT_TYPE_UINT,
439 	FORMAT_TYPE_INT,
440 	FORMAT_TYPE_SIZE_T,
441 	FORMAT_TYPE_PTRDIFF
442 };
443 
444 struct printf_spec {
445 	unsigned int	type:8;		/* format_type enum */
446 	signed int	field_width:24;	/* width of output field */
447 	unsigned int	flags:8;	/* flags to number() */
448 	unsigned int	base:8;		/* number base, 8, 10 or 16 only */
449 	signed int	precision:16;	/* # of digits/chars */
450 } __packed;
451 static_assert(sizeof(struct printf_spec) == 8);
452 
453 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
454 #define PRECISION_MAX ((1 << 15) - 1)
455 
456 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)457 char *number(char *buf, char *end, unsigned long long num,
458 	     struct printf_spec spec)
459 {
460 	/* put_dec requires 2-byte alignment of the buffer. */
461 	char tmp[3 * sizeof(num)] __aligned(2);
462 	char sign;
463 	char locase;
464 	int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
465 	int i;
466 	bool is_zero = num == 0LL;
467 	int field_width = spec.field_width;
468 	int precision = spec.precision;
469 
470 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
471 	 * produces same digits or (maybe lowercased) letters */
472 	locase = (spec.flags & SMALL);
473 	if (spec.flags & LEFT)
474 		spec.flags &= ~ZEROPAD;
475 	sign = 0;
476 	if (spec.flags & SIGN) {
477 		if ((signed long long)num < 0) {
478 			sign = '-';
479 			num = -(signed long long)num;
480 			field_width--;
481 		} else if (spec.flags & PLUS) {
482 			sign = '+';
483 			field_width--;
484 		} else if (spec.flags & SPACE) {
485 			sign = ' ';
486 			field_width--;
487 		}
488 	}
489 	if (need_pfx) {
490 		if (spec.base == 16)
491 			field_width -= 2;
492 		else if (!is_zero)
493 			field_width--;
494 	}
495 
496 	/* generate full string in tmp[], in reverse order */
497 	i = 0;
498 	if (num < spec.base)
499 		tmp[i++] = hex_asc_upper[num] | locase;
500 	else if (spec.base != 10) { /* 8 or 16 */
501 		int mask = spec.base - 1;
502 		int shift = 3;
503 
504 		if (spec.base == 16)
505 			shift = 4;
506 		do {
507 			tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
508 			num >>= shift;
509 		} while (num);
510 	} else { /* base 10 */
511 		i = put_dec(tmp, num) - tmp;
512 	}
513 
514 	/* printing 100 using %2d gives "100", not "00" */
515 	if (i > precision)
516 		precision = i;
517 	/* leading space padding */
518 	field_width -= precision;
519 	if (!(spec.flags & (ZEROPAD | LEFT))) {
520 		while (--field_width >= 0) {
521 			if (buf < end)
522 				*buf = ' ';
523 			++buf;
524 		}
525 	}
526 	/* sign */
527 	if (sign) {
528 		if (buf < end)
529 			*buf = sign;
530 		++buf;
531 	}
532 	/* "0x" / "0" prefix */
533 	if (need_pfx) {
534 		if (spec.base == 16 || !is_zero) {
535 			if (buf < end)
536 				*buf = '0';
537 			++buf;
538 		}
539 		if (spec.base == 16) {
540 			if (buf < end)
541 				*buf = ('X' | locase);
542 			++buf;
543 		}
544 	}
545 	/* zero or space padding */
546 	if (!(spec.flags & LEFT)) {
547 		char c = ' ' + (spec.flags & ZEROPAD);
548 
549 		while (--field_width >= 0) {
550 			if (buf < end)
551 				*buf = c;
552 			++buf;
553 		}
554 	}
555 	/* hmm even more zero padding? */
556 	while (i <= --precision) {
557 		if (buf < end)
558 			*buf = '0';
559 		++buf;
560 	}
561 	/* actual digits of result */
562 	while (--i >= 0) {
563 		if (buf < end)
564 			*buf = tmp[i];
565 		++buf;
566 	}
567 	/* trailing space padding */
568 	while (--field_width >= 0) {
569 		if (buf < end)
570 			*buf = ' ';
571 		++buf;
572 	}
573 
574 	return buf;
575 }
576 
577 static noinline_for_stack
special_hex_number(char * buf,char * end,unsigned long long num,int size)578 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
579 {
580 	struct printf_spec spec;
581 
582 	spec.type = FORMAT_TYPE_PTR;
583 	spec.field_width = 2 + 2 * size;	/* 0x + hex */
584 	spec.flags = SPECIAL | SMALL | ZEROPAD;
585 	spec.base = 16;
586 	spec.precision = -1;
587 
588 	return number(buf, end, num, spec);
589 }
590 
move_right(char * buf,char * end,unsigned len,unsigned spaces)591 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
592 {
593 	size_t size;
594 	if (buf >= end)	/* nowhere to put anything */
595 		return;
596 	size = end - buf;
597 	if (size <= spaces) {
598 		memset(buf, ' ', size);
599 		return;
600 	}
601 	if (len) {
602 		if (len > size - spaces)
603 			len = size - spaces;
604 		memmove(buf + spaces, buf, len);
605 	}
606 	memset(buf, ' ', spaces);
607 }
608 
609 /*
610  * Handle field width padding for a string.
611  * @buf: current buffer position
612  * @n: length of string
613  * @end: end of output buffer
614  * @spec: for field width and flags
615  * Returns: new buffer position after padding.
616  */
617 static noinline_for_stack
widen_string(char * buf,int n,char * end,struct printf_spec spec)618 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
619 {
620 	unsigned spaces;
621 
622 	if (likely(n >= spec.field_width))
623 		return buf;
624 	/* we want to pad the sucker */
625 	spaces = spec.field_width - n;
626 	if (!(spec.flags & LEFT)) {
627 		move_right(buf - n, end, n, spaces);
628 		return buf + spaces;
629 	}
630 	while (spaces--) {
631 		if (buf < end)
632 			*buf = ' ';
633 		++buf;
634 	}
635 	return buf;
636 }
637 
638 /* Handle string from a well known address. */
string_nocheck(char * buf,char * end,const char * s,struct printf_spec spec)639 static char *string_nocheck(char *buf, char *end, const char *s,
640 			    struct printf_spec spec)
641 {
642 	int len = 0;
643 	int lim = spec.precision;
644 
645 	while (lim--) {
646 		char c = *s++;
647 		if (!c)
648 			break;
649 		if (buf < end)
650 			*buf = c;
651 		++buf;
652 		++len;
653 	}
654 	return widen_string(buf, len, end, spec);
655 }
656 
err_ptr(char * buf,char * end,void * ptr,struct printf_spec spec)657 static char *err_ptr(char *buf, char *end, void *ptr,
658 		     struct printf_spec spec)
659 {
660 	int err = PTR_ERR(ptr);
661 	const char *sym = errname(err);
662 
663 	if (sym)
664 		return string_nocheck(buf, end, sym, spec);
665 
666 	/*
667 	 * Somebody passed ERR_PTR(-1234) or some other non-existing
668 	 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
669 	 * printing it as its decimal representation.
670 	 */
671 	spec.flags |= SIGN;
672 	spec.base = 10;
673 	return number(buf, end, err, spec);
674 }
675 
676 /* Be careful: error messages must fit into the given buffer. */
error_string(char * buf,char * end,const char * s,struct printf_spec spec)677 static char *error_string(char *buf, char *end, const char *s,
678 			  struct printf_spec spec)
679 {
680 	/*
681 	 * Hard limit to avoid a completely insane messages. It actually
682 	 * works pretty well because most error messages are in
683 	 * the many pointer format modifiers.
684 	 */
685 	if (spec.precision == -1)
686 		spec.precision = 2 * sizeof(void *);
687 
688 	return string_nocheck(buf, end, s, spec);
689 }
690 
691 /*
692  * Do not call any complex external code here. Nested printk()/vsprintf()
693  * might cause infinite loops. Failures might break printk() and would
694  * be hard to debug.
695  */
check_pointer_msg(const void * ptr)696 static const char *check_pointer_msg(const void *ptr)
697 {
698 	if (!ptr)
699 		return "(null)";
700 
701 	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
702 		return "(efault)";
703 
704 	return NULL;
705 }
706 
check_pointer(char ** buf,char * end,const void * ptr,struct printf_spec spec)707 static int check_pointer(char **buf, char *end, const void *ptr,
708 			 struct printf_spec spec)
709 {
710 	const char *err_msg;
711 
712 	err_msg = check_pointer_msg(ptr);
713 	if (err_msg) {
714 		*buf = error_string(*buf, end, err_msg, spec);
715 		return -EFAULT;
716 	}
717 
718 	return 0;
719 }
720 
721 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)722 char *string(char *buf, char *end, const char *s,
723 	     struct printf_spec spec)
724 {
725 	if (check_pointer(&buf, end, s, spec))
726 		return buf;
727 
728 	return string_nocheck(buf, end, s, spec);
729 }
730 
pointer_string(char * buf,char * end,const void * ptr,struct printf_spec spec)731 static char *pointer_string(char *buf, char *end,
732 			    const void *ptr,
733 			    struct printf_spec spec)
734 {
735 	spec.base = 16;
736 	spec.flags |= SMALL;
737 	if (spec.field_width == -1) {
738 		spec.field_width = 2 * sizeof(ptr);
739 		spec.flags |= ZEROPAD;
740 	}
741 
742 	return number(buf, end, (unsigned long int)ptr, spec);
743 }
744 
745 /* Make pointers available for printing early in the boot sequence. */
746 static int debug_boot_weak_hash __ro_after_init;
747 
debug_boot_weak_hash_enable(char * str)748 static int __init debug_boot_weak_hash_enable(char *str)
749 {
750 	debug_boot_weak_hash = 1;
751 	pr_info("debug_boot_weak_hash enabled\n");
752 	return 0;
753 }
754 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
755 
756 static bool filled_random_ptr_key __read_mostly;
757 static siphash_key_t ptr_key __read_mostly;
758 
fill_ptr_key(struct notifier_block * nb,unsigned long action,void * data)759 static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data)
760 {
761 	get_random_bytes(&ptr_key, sizeof(ptr_key));
762 
763 	/* Pairs with smp_rmb() before reading ptr_key. */
764 	smp_wmb();
765 	WRITE_ONCE(filled_random_ptr_key, true);
766 	return NOTIFY_DONE;
767 }
768 
vsprintf_init_hashval(void)769 static int __init vsprintf_init_hashval(void)
770 {
771 	static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key };
772 	execute_with_initialized_rng(&fill_ptr_key_nb);
773 	return 0;
774 }
subsys_initcall(vsprintf_init_hashval)775 subsys_initcall(vsprintf_init_hashval)
776 
777 /* Maps a pointer to a 32 bit unique identifier. */
778 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
779 {
780 	unsigned long hashval;
781 
782 	if (!READ_ONCE(filled_random_ptr_key))
783 		return -EBUSY;
784 
785 	/* Pairs with smp_wmb() after writing ptr_key. */
786 	smp_rmb();
787 
788 #ifdef CONFIG_64BIT
789 	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
790 	/*
791 	 * Mask off the first 32 bits, this makes explicit that we have
792 	 * modified the address (and 32 bits is plenty for a unique ID).
793 	 */
794 	hashval = hashval & 0xffffffff;
795 #else
796 	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
797 #endif
798 	*hashval_out = hashval;
799 	return 0;
800 }
801 
ptr_to_hashval(const void * ptr,unsigned long * hashval_out)802 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
803 {
804 	return __ptr_to_hashval(ptr, hashval_out);
805 }
806 
ptr_to_id(char * buf,char * end,const void * ptr,struct printf_spec spec)807 static char *ptr_to_id(char *buf, char *end, const void *ptr,
808 		       struct printf_spec spec)
809 {
810 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
811 	unsigned long hashval;
812 	int ret;
813 
814 	/*
815 	 * Print the real pointer value for NULL and error pointers,
816 	 * as they are not actual addresses.
817 	 */
818 	if (IS_ERR_OR_NULL(ptr))
819 		return pointer_string(buf, end, ptr, spec);
820 
821 	/* When debugging early boot use non-cryptographically secure hash. */
822 	if (unlikely(debug_boot_weak_hash)) {
823 		hashval = hash_long((unsigned long)ptr, 32);
824 		return pointer_string(buf, end, (const void *)hashval, spec);
825 	}
826 
827 	ret = __ptr_to_hashval(ptr, &hashval);
828 	if (ret) {
829 		spec.field_width = 2 * sizeof(ptr);
830 		/* string length must be less than default_width */
831 		return error_string(buf, end, str, spec);
832 	}
833 
834 	return pointer_string(buf, end, (const void *)hashval, spec);
835 }
836 
default_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)837 static char *default_pointer(char *buf, char *end, const void *ptr,
838 			     struct printf_spec spec)
839 {
840 	/*
841 	 * default is to _not_ leak addresses, so hash before printing,
842 	 * unless no_hash_pointers is specified on the command line.
843 	 */
844 	if (unlikely(no_hash_pointers))
845 		return pointer_string(buf, end, ptr, spec);
846 
847 	return ptr_to_id(buf, end, ptr, spec);
848 }
849 
850 int kptr_restrict __read_mostly;
851 
852 static noinline_for_stack
restricted_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)853 char *restricted_pointer(char *buf, char *end, const void *ptr,
854 			 struct printf_spec spec)
855 {
856 	switch (kptr_restrict) {
857 	case 0:
858 		/* Handle as %p, hash and do _not_ leak addresses. */
859 		return default_pointer(buf, end, ptr, spec);
860 	case 1: {
861 		const struct cred *cred;
862 
863 		/*
864 		 * kptr_restrict==1 cannot be used in IRQ context
865 		 * because its test for CAP_SYSLOG would be meaningless.
866 		 */
867 		if (in_hardirq() || in_serving_softirq() || in_nmi()) {
868 			if (spec.field_width == -1)
869 				spec.field_width = 2 * sizeof(ptr);
870 			return error_string(buf, end, "pK-error", spec);
871 		}
872 
873 		/*
874 		 * Only print the real pointer value if the current
875 		 * process has CAP_SYSLOG and is running with the
876 		 * same credentials it started with. This is because
877 		 * access to files is checked at open() time, but %pK
878 		 * checks permission at read() time. We don't want to
879 		 * leak pointer values if a binary opens a file using
880 		 * %pK and then elevates privileges before reading it.
881 		 */
882 		cred = current_cred();
883 		if (!has_capability_noaudit(current, CAP_SYSLOG) ||
884 		    !uid_eq(cred->euid, cred->uid) ||
885 		    !gid_eq(cred->egid, cred->gid))
886 			ptr = NULL;
887 		break;
888 	}
889 	case 2:
890 	default:
891 		/* Always print 0's for %pK */
892 		ptr = NULL;
893 		break;
894 	}
895 
896 	return pointer_string(buf, end, ptr, spec);
897 }
898 
899 static noinline_for_stack
dentry_name(char * buf,char * end,const struct dentry * d,struct printf_spec spec,const char * fmt)900 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
901 		  const char *fmt)
902 {
903 	const char *array[4], *s;
904 	const struct dentry *p;
905 	int depth;
906 	int i, n;
907 
908 	switch (fmt[1]) {
909 		case '2': case '3': case '4':
910 			depth = fmt[1] - '0';
911 			break;
912 		default:
913 			depth = 1;
914 	}
915 
916 	rcu_read_lock();
917 	for (i = 0; i < depth; i++, d = p) {
918 		if (check_pointer(&buf, end, d, spec)) {
919 			rcu_read_unlock();
920 			return buf;
921 		}
922 
923 		p = READ_ONCE(d->d_parent);
924 		array[i] = READ_ONCE(d->d_name.name);
925 		if (p == d) {
926 			if (i)
927 				array[i] = "";
928 			i++;
929 			break;
930 		}
931 	}
932 	s = array[--i];
933 	for (n = 0; n != spec.precision; n++, buf++) {
934 		char c = *s++;
935 		if (!c) {
936 			if (!i)
937 				break;
938 			c = '/';
939 			s = array[--i];
940 		}
941 		if (buf < end)
942 			*buf = c;
943 	}
944 	rcu_read_unlock();
945 	return widen_string(buf, n, end, spec);
946 }
947 
948 static noinline_for_stack
file_dentry_name(char * buf,char * end,const struct file * f,struct printf_spec spec,const char * fmt)949 char *file_dentry_name(char *buf, char *end, const struct file *f,
950 			struct printf_spec spec, const char *fmt)
951 {
952 	if (check_pointer(&buf, end, f, spec))
953 		return buf;
954 
955 	return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
956 }
957 #ifdef CONFIG_BLOCK
958 static noinline_for_stack
bdev_name(char * buf,char * end,struct block_device * bdev,struct printf_spec spec,const char * fmt)959 char *bdev_name(char *buf, char *end, struct block_device *bdev,
960 		struct printf_spec spec, const char *fmt)
961 {
962 	struct gendisk *hd;
963 
964 	if (check_pointer(&buf, end, bdev, spec))
965 		return buf;
966 
967 	hd = bdev->bd_disk;
968 	buf = string(buf, end, hd->disk_name, spec);
969 	if (bdev_is_partition(bdev)) {
970 		if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
971 			if (buf < end)
972 				*buf = 'p';
973 			buf++;
974 		}
975 		buf = number(buf, end, bdev_partno(bdev), spec);
976 	}
977 	return buf;
978 }
979 #endif
980 
981 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)982 char *symbol_string(char *buf, char *end, void *ptr,
983 		    struct printf_spec spec, const char *fmt)
984 {
985 	unsigned long value;
986 #ifdef CONFIG_KALLSYMS
987 	char sym[KSYM_SYMBOL_LEN];
988 #endif
989 
990 	if (fmt[1] == 'R')
991 		ptr = __builtin_extract_return_addr(ptr);
992 	value = (unsigned long)ptr;
993 
994 #ifdef CONFIG_KALLSYMS
995 	if (*fmt == 'B' && fmt[1] == 'b')
996 		sprint_backtrace_build_id(sym, value);
997 	else if (*fmt == 'B')
998 		sprint_backtrace(sym, value);
999 	else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1000 		sprint_symbol_build_id(sym, value);
1001 	else if (*fmt != 's')
1002 		sprint_symbol(sym, value);
1003 	else
1004 		sprint_symbol_no_offset(sym, value);
1005 
1006 	return string_nocheck(buf, end, sym, spec);
1007 #else
1008 	return special_hex_number(buf, end, value, sizeof(void *));
1009 #endif
1010 }
1011 
1012 static const struct printf_spec default_str_spec = {
1013 	.field_width = -1,
1014 	.precision = -1,
1015 };
1016 
1017 static const struct printf_spec default_flag_spec = {
1018 	.base = 16,
1019 	.precision = -1,
1020 	.flags = SPECIAL | SMALL,
1021 };
1022 
1023 static const struct printf_spec default_dec_spec = {
1024 	.base = 10,
1025 	.precision = -1,
1026 };
1027 
1028 static const struct printf_spec default_dec02_spec = {
1029 	.base = 10,
1030 	.field_width = 2,
1031 	.precision = -1,
1032 	.flags = ZEROPAD,
1033 };
1034 
1035 static const struct printf_spec default_dec04_spec = {
1036 	.base = 10,
1037 	.field_width = 4,
1038 	.precision = -1,
1039 	.flags = ZEROPAD,
1040 };
1041 
1042 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)1043 char *resource_string(char *buf, char *end, struct resource *res,
1044 		      struct printf_spec spec, const char *fmt)
1045 {
1046 #ifndef IO_RSRC_PRINTK_SIZE
1047 #define IO_RSRC_PRINTK_SIZE	6
1048 #endif
1049 
1050 #ifndef MEM_RSRC_PRINTK_SIZE
1051 #define MEM_RSRC_PRINTK_SIZE	10
1052 #endif
1053 	static const struct printf_spec io_spec = {
1054 		.base = 16,
1055 		.field_width = IO_RSRC_PRINTK_SIZE,
1056 		.precision = -1,
1057 		.flags = SPECIAL | SMALL | ZEROPAD,
1058 	};
1059 	static const struct printf_spec mem_spec = {
1060 		.base = 16,
1061 		.field_width = MEM_RSRC_PRINTK_SIZE,
1062 		.precision = -1,
1063 		.flags = SPECIAL | SMALL | ZEROPAD,
1064 	};
1065 	static const struct printf_spec bus_spec = {
1066 		.base = 16,
1067 		.field_width = 2,
1068 		.precision = -1,
1069 		.flags = SMALL | ZEROPAD,
1070 	};
1071 	static const struct printf_spec str_spec = {
1072 		.field_width = -1,
1073 		.precision = 10,
1074 		.flags = LEFT,
1075 	};
1076 
1077 	/* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1078 	 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1079 #define RSRC_BUF_SIZE		((2 * sizeof(resource_size_t)) + 4)
1080 #define FLAG_BUF_SIZE		(2 * sizeof(res->flags))
1081 #define DECODED_BUF_SIZE	sizeof("[mem - 64bit pref window disabled]")
1082 #define RAW_BUF_SIZE		sizeof("[mem - flags 0x]")
1083 	char sym[MAX(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1084 		     2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1085 
1086 	char *p = sym, *pend = sym + sizeof(sym);
1087 	int decode = (fmt[0] == 'R') ? 1 : 0;
1088 	const struct printf_spec *specp;
1089 
1090 	if (check_pointer(&buf, end, res, spec))
1091 		return buf;
1092 
1093 	*p++ = '[';
1094 	if (res->flags & IORESOURCE_IO) {
1095 		p = string_nocheck(p, pend, "io  ", str_spec);
1096 		specp = &io_spec;
1097 	} else if (res->flags & IORESOURCE_MEM) {
1098 		p = string_nocheck(p, pend, "mem ", str_spec);
1099 		specp = &mem_spec;
1100 	} else if (res->flags & IORESOURCE_IRQ) {
1101 		p = string_nocheck(p, pend, "irq ", str_spec);
1102 		specp = &default_dec_spec;
1103 	} else if (res->flags & IORESOURCE_DMA) {
1104 		p = string_nocheck(p, pend, "dma ", str_spec);
1105 		specp = &default_dec_spec;
1106 	} else if (res->flags & IORESOURCE_BUS) {
1107 		p = string_nocheck(p, pend, "bus ", str_spec);
1108 		specp = &bus_spec;
1109 	} else {
1110 		p = string_nocheck(p, pend, "??? ", str_spec);
1111 		specp = &mem_spec;
1112 		decode = 0;
1113 	}
1114 	if (decode && res->flags & IORESOURCE_UNSET) {
1115 		p = string_nocheck(p, pend, "size ", str_spec);
1116 		p = number(p, pend, resource_size(res), *specp);
1117 	} else {
1118 		p = number(p, pend, res->start, *specp);
1119 		if (res->start != res->end) {
1120 			*p++ = '-';
1121 			p = number(p, pend, res->end, *specp);
1122 		}
1123 	}
1124 	if (decode) {
1125 		if (res->flags & IORESOURCE_MEM_64)
1126 			p = string_nocheck(p, pend, " 64bit", str_spec);
1127 		if (res->flags & IORESOURCE_PREFETCH)
1128 			p = string_nocheck(p, pend, " pref", str_spec);
1129 		if (res->flags & IORESOURCE_WINDOW)
1130 			p = string_nocheck(p, pend, " window", str_spec);
1131 		if (res->flags & IORESOURCE_DISABLED)
1132 			p = string_nocheck(p, pend, " disabled", str_spec);
1133 	} else {
1134 		p = string_nocheck(p, pend, " flags ", str_spec);
1135 		p = number(p, pend, res->flags, default_flag_spec);
1136 	}
1137 	*p++ = ']';
1138 	*p = '\0';
1139 
1140 	return string_nocheck(buf, end, sym, spec);
1141 }
1142 
1143 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1144 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1145 		 const char *fmt)
1146 {
1147 	int i, len = 1;		/* if we pass '%ph[CDN]', field width remains
1148 				   negative value, fallback to the default */
1149 	char separator;
1150 
1151 	if (spec.field_width == 0)
1152 		/* nothing to print */
1153 		return buf;
1154 
1155 	if (check_pointer(&buf, end, addr, spec))
1156 		return buf;
1157 
1158 	switch (fmt[1]) {
1159 	case 'C':
1160 		separator = ':';
1161 		break;
1162 	case 'D':
1163 		separator = '-';
1164 		break;
1165 	case 'N':
1166 		separator = 0;
1167 		break;
1168 	default:
1169 		separator = ' ';
1170 		break;
1171 	}
1172 
1173 	if (spec.field_width > 0)
1174 		len = min_t(int, spec.field_width, 64);
1175 
1176 	for (i = 0; i < len; ++i) {
1177 		if (buf < end)
1178 			*buf = hex_asc_hi(addr[i]);
1179 		++buf;
1180 		if (buf < end)
1181 			*buf = hex_asc_lo(addr[i]);
1182 		++buf;
1183 
1184 		if (separator && i != len - 1) {
1185 			if (buf < end)
1186 				*buf = separator;
1187 			++buf;
1188 		}
1189 	}
1190 
1191 	return buf;
1192 }
1193 
1194 static noinline_for_stack
bitmap_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1195 char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
1196 		    struct printf_spec spec, const char *fmt)
1197 {
1198 	const int CHUNKSZ = 32;
1199 	int nr_bits = max_t(int, spec.field_width, 0);
1200 	int i, chunksz;
1201 	bool first = true;
1202 
1203 	if (check_pointer(&buf, end, bitmap, spec))
1204 		return buf;
1205 
1206 	/* reused to print numbers */
1207 	spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1208 
1209 	chunksz = nr_bits & (CHUNKSZ - 1);
1210 	if (chunksz == 0)
1211 		chunksz = CHUNKSZ;
1212 
1213 	i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1214 	for (; i >= 0; i -= CHUNKSZ) {
1215 		u32 chunkmask, val;
1216 		int word, bit;
1217 
1218 		chunkmask = ((1ULL << chunksz) - 1);
1219 		word = i / BITS_PER_LONG;
1220 		bit = i % BITS_PER_LONG;
1221 		val = (bitmap[word] >> bit) & chunkmask;
1222 
1223 		if (!first) {
1224 			if (buf < end)
1225 				*buf = ',';
1226 			buf++;
1227 		}
1228 		first = false;
1229 
1230 		spec.field_width = DIV_ROUND_UP(chunksz, 4);
1231 		buf = number(buf, end, val, spec);
1232 
1233 		chunksz = CHUNKSZ;
1234 	}
1235 	return buf;
1236 }
1237 
1238 static noinline_for_stack
bitmap_list_string(char * buf,char * end,const unsigned long * bitmap,struct printf_spec spec,const char * fmt)1239 char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
1240 			 struct printf_spec spec, const char *fmt)
1241 {
1242 	int nr_bits = max_t(int, spec.field_width, 0);
1243 	bool first = true;
1244 	int rbot, rtop;
1245 
1246 	if (check_pointer(&buf, end, bitmap, spec))
1247 		return buf;
1248 
1249 	for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
1250 		if (!first) {
1251 			if (buf < end)
1252 				*buf = ',';
1253 			buf++;
1254 		}
1255 		first = false;
1256 
1257 		buf = number(buf, end, rbot, default_dec_spec);
1258 		if (rtop == rbot + 1)
1259 			continue;
1260 
1261 		if (buf < end)
1262 			*buf = '-';
1263 		buf = number(++buf, end, rtop - 1, default_dec_spec);
1264 	}
1265 	return buf;
1266 }
1267 
1268 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1269 char *mac_address_string(char *buf, char *end, u8 *addr,
1270 			 struct printf_spec spec, const char *fmt)
1271 {
1272 	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1273 	char *p = mac_addr;
1274 	int i;
1275 	char separator;
1276 	bool reversed = false;
1277 
1278 	if (check_pointer(&buf, end, addr, spec))
1279 		return buf;
1280 
1281 	switch (fmt[1]) {
1282 	case 'F':
1283 		separator = '-';
1284 		break;
1285 
1286 	case 'R':
1287 		reversed = true;
1288 		fallthrough;
1289 
1290 	default:
1291 		separator = ':';
1292 		break;
1293 	}
1294 
1295 	for (i = 0; i < 6; i++) {
1296 		if (reversed)
1297 			p = hex_byte_pack(p, addr[5 - i]);
1298 		else
1299 			p = hex_byte_pack(p, addr[i]);
1300 
1301 		if (fmt[0] == 'M' && i != 5)
1302 			*p++ = separator;
1303 	}
1304 	*p = '\0';
1305 
1306 	return string_nocheck(buf, end, mac_addr, spec);
1307 }
1308 
1309 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)1310 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1311 {
1312 	int i;
1313 	bool leading_zeros = (fmt[0] == 'i');
1314 	int index;
1315 	int step;
1316 
1317 	switch (fmt[2]) {
1318 	case 'h':
1319 #ifdef __BIG_ENDIAN
1320 		index = 0;
1321 		step = 1;
1322 #else
1323 		index = 3;
1324 		step = -1;
1325 #endif
1326 		break;
1327 	case 'l':
1328 		index = 3;
1329 		step = -1;
1330 		break;
1331 	case 'n':
1332 	case 'b':
1333 	default:
1334 		index = 0;
1335 		step = 1;
1336 		break;
1337 	}
1338 	for (i = 0; i < 4; i++) {
1339 		char temp[4] __aligned(2);	/* hold each IP quad in reverse order */
1340 		int digits = put_dec_trunc8(temp, addr[index]) - temp;
1341 		if (leading_zeros) {
1342 			if (digits < 3)
1343 				*p++ = '0';
1344 			if (digits < 2)
1345 				*p++ = '0';
1346 		}
1347 		/* reverse the digits in the quad */
1348 		while (digits--)
1349 			*p++ = temp[digits];
1350 		if (i < 3)
1351 			*p++ = '.';
1352 		index += step;
1353 	}
1354 	*p = '\0';
1355 
1356 	return p;
1357 }
1358 
1359 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)1360 char *ip6_compressed_string(char *p, const char *addr)
1361 {
1362 	int i, j, range;
1363 	unsigned char zerolength[8];
1364 	int longest = 1;
1365 	int colonpos = -1;
1366 	u16 word;
1367 	u8 hi, lo;
1368 	bool needcolon = false;
1369 	bool useIPv4;
1370 	struct in6_addr in6;
1371 
1372 	memcpy(&in6, addr, sizeof(struct in6_addr));
1373 
1374 	useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1375 
1376 	memset(zerolength, 0, sizeof(zerolength));
1377 
1378 	if (useIPv4)
1379 		range = 6;
1380 	else
1381 		range = 8;
1382 
1383 	/* find position of longest 0 run */
1384 	for (i = 0; i < range; i++) {
1385 		for (j = i; j < range; j++) {
1386 			if (in6.s6_addr16[j] != 0)
1387 				break;
1388 			zerolength[i]++;
1389 		}
1390 	}
1391 	for (i = 0; i < range; i++) {
1392 		if (zerolength[i] > longest) {
1393 			longest = zerolength[i];
1394 			colonpos = i;
1395 		}
1396 	}
1397 	if (longest == 1)		/* don't compress a single 0 */
1398 		colonpos = -1;
1399 
1400 	/* emit address */
1401 	for (i = 0; i < range; i++) {
1402 		if (i == colonpos) {
1403 			if (needcolon || i == 0)
1404 				*p++ = ':';
1405 			*p++ = ':';
1406 			needcolon = false;
1407 			i += longest - 1;
1408 			continue;
1409 		}
1410 		if (needcolon) {
1411 			*p++ = ':';
1412 			needcolon = false;
1413 		}
1414 		/* hex u16 without leading 0s */
1415 		word = ntohs(in6.s6_addr16[i]);
1416 		hi = word >> 8;
1417 		lo = word & 0xff;
1418 		if (hi) {
1419 			if (hi > 0x0f)
1420 				p = hex_byte_pack(p, hi);
1421 			else
1422 				*p++ = hex_asc_lo(hi);
1423 			p = hex_byte_pack(p, lo);
1424 		}
1425 		else if (lo > 0x0f)
1426 			p = hex_byte_pack(p, lo);
1427 		else
1428 			*p++ = hex_asc_lo(lo);
1429 		needcolon = true;
1430 	}
1431 
1432 	if (useIPv4) {
1433 		if (needcolon)
1434 			*p++ = ':';
1435 		p = ip4_string(p, &in6.s6_addr[12], "I4");
1436 	}
1437 	*p = '\0';
1438 
1439 	return p;
1440 }
1441 
1442 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)1443 char *ip6_string(char *p, const char *addr, const char *fmt)
1444 {
1445 	int i;
1446 
1447 	for (i = 0; i < 8; i++) {
1448 		p = hex_byte_pack(p, *addr++);
1449 		p = hex_byte_pack(p, *addr++);
1450 		if (fmt[0] == 'I' && i != 7)
1451 			*p++ = ':';
1452 	}
1453 	*p = '\0';
1454 
1455 	return p;
1456 }
1457 
1458 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1459 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1460 		      struct printf_spec spec, const char *fmt)
1461 {
1462 	char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1463 
1464 	if (fmt[0] == 'I' && fmt[2] == 'c')
1465 		ip6_compressed_string(ip6_addr, addr);
1466 	else
1467 		ip6_string(ip6_addr, addr, fmt);
1468 
1469 	return string_nocheck(buf, end, ip6_addr, spec);
1470 }
1471 
1472 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1473 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1474 		      struct printf_spec spec, const char *fmt)
1475 {
1476 	char ip4_addr[sizeof("255.255.255.255")];
1477 
1478 	ip4_string(ip4_addr, addr, fmt);
1479 
1480 	return string_nocheck(buf, end, ip4_addr, spec);
1481 }
1482 
1483 static noinline_for_stack
ip6_addr_string_sa(char * buf,char * end,const struct sockaddr_in6 * sa,struct printf_spec spec,const char * fmt)1484 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1485 			 struct printf_spec spec, const char *fmt)
1486 {
1487 	bool have_p = false, have_s = false, have_f = false, have_c = false;
1488 	char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1489 		      sizeof(":12345") + sizeof("/123456789") +
1490 		      sizeof("%1234567890")];
1491 	char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1492 	const u8 *addr = (const u8 *) &sa->sin6_addr;
1493 	char fmt6[2] = { fmt[0], '6' };
1494 	u8 off = 0;
1495 
1496 	fmt++;
1497 	while (isalpha(*++fmt)) {
1498 		switch (*fmt) {
1499 		case 'p':
1500 			have_p = true;
1501 			break;
1502 		case 'f':
1503 			have_f = true;
1504 			break;
1505 		case 's':
1506 			have_s = true;
1507 			break;
1508 		case 'c':
1509 			have_c = true;
1510 			break;
1511 		}
1512 	}
1513 
1514 	if (have_p || have_s || have_f) {
1515 		*p = '[';
1516 		off = 1;
1517 	}
1518 
1519 	if (fmt6[0] == 'I' && have_c)
1520 		p = ip6_compressed_string(ip6_addr + off, addr);
1521 	else
1522 		p = ip6_string(ip6_addr + off, addr, fmt6);
1523 
1524 	if (have_p || have_s || have_f)
1525 		*p++ = ']';
1526 
1527 	if (have_p) {
1528 		*p++ = ':';
1529 		p = number(p, pend, ntohs(sa->sin6_port), spec);
1530 	}
1531 	if (have_f) {
1532 		*p++ = '/';
1533 		p = number(p, pend, ntohl(sa->sin6_flowinfo &
1534 					  IPV6_FLOWINFO_MASK), spec);
1535 	}
1536 	if (have_s) {
1537 		*p++ = '%';
1538 		p = number(p, pend, sa->sin6_scope_id, spec);
1539 	}
1540 	*p = '\0';
1541 
1542 	return string_nocheck(buf, end, ip6_addr, spec);
1543 }
1544 
1545 static noinline_for_stack
ip4_addr_string_sa(char * buf,char * end,const struct sockaddr_in * sa,struct printf_spec spec,const char * fmt)1546 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1547 			 struct printf_spec spec, const char *fmt)
1548 {
1549 	bool have_p = false;
1550 	char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1551 	char *pend = ip4_addr + sizeof(ip4_addr);
1552 	const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1553 	char fmt4[3] = { fmt[0], '4', 0 };
1554 
1555 	fmt++;
1556 	while (isalpha(*++fmt)) {
1557 		switch (*fmt) {
1558 		case 'p':
1559 			have_p = true;
1560 			break;
1561 		case 'h':
1562 		case 'l':
1563 		case 'n':
1564 		case 'b':
1565 			fmt4[2] = *fmt;
1566 			break;
1567 		}
1568 	}
1569 
1570 	p = ip4_string(ip4_addr, addr, fmt4);
1571 	if (have_p) {
1572 		*p++ = ':';
1573 		p = number(p, pend, ntohs(sa->sin_port), spec);
1574 	}
1575 	*p = '\0';
1576 
1577 	return string_nocheck(buf, end, ip4_addr, spec);
1578 }
1579 
1580 static noinline_for_stack
ip_addr_string(char * buf,char * end,const void * ptr,struct printf_spec spec,const char * fmt)1581 char *ip_addr_string(char *buf, char *end, const void *ptr,
1582 		     struct printf_spec spec, const char *fmt)
1583 {
1584 	char *err_fmt_msg;
1585 
1586 	if (check_pointer(&buf, end, ptr, spec))
1587 		return buf;
1588 
1589 	switch (fmt[1]) {
1590 	case '6':
1591 		return ip6_addr_string(buf, end, ptr, spec, fmt);
1592 	case '4':
1593 		return ip4_addr_string(buf, end, ptr, spec, fmt);
1594 	case 'S': {
1595 		const union {
1596 			struct sockaddr		raw;
1597 			struct sockaddr_in	v4;
1598 			struct sockaddr_in6	v6;
1599 		} *sa = ptr;
1600 
1601 		switch (sa->raw.sa_family) {
1602 		case AF_INET:
1603 			return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1604 		case AF_INET6:
1605 			return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1606 		default:
1607 			return error_string(buf, end, "(einval)", spec);
1608 		}}
1609 	}
1610 
1611 	err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1612 	return error_string(buf, end, err_fmt_msg, spec);
1613 }
1614 
1615 static noinline_for_stack
escaped_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1616 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1617 		     const char *fmt)
1618 {
1619 	bool found = true;
1620 	int count = 1;
1621 	unsigned int flags = 0;
1622 	int len;
1623 
1624 	if (spec.field_width == 0)
1625 		return buf;				/* nothing to print */
1626 
1627 	if (check_pointer(&buf, end, addr, spec))
1628 		return buf;
1629 
1630 	do {
1631 		switch (fmt[count++]) {
1632 		case 'a':
1633 			flags |= ESCAPE_ANY;
1634 			break;
1635 		case 'c':
1636 			flags |= ESCAPE_SPECIAL;
1637 			break;
1638 		case 'h':
1639 			flags |= ESCAPE_HEX;
1640 			break;
1641 		case 'n':
1642 			flags |= ESCAPE_NULL;
1643 			break;
1644 		case 'o':
1645 			flags |= ESCAPE_OCTAL;
1646 			break;
1647 		case 'p':
1648 			flags |= ESCAPE_NP;
1649 			break;
1650 		case 's':
1651 			flags |= ESCAPE_SPACE;
1652 			break;
1653 		default:
1654 			found = false;
1655 			break;
1656 		}
1657 	} while (found);
1658 
1659 	if (!flags)
1660 		flags = ESCAPE_ANY_NP;
1661 
1662 	len = spec.field_width < 0 ? 1 : spec.field_width;
1663 
1664 	/*
1665 	 * string_escape_mem() writes as many characters as it can to
1666 	 * the given buffer, and returns the total size of the output
1667 	 * had the buffer been big enough.
1668 	 */
1669 	buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1670 
1671 	return buf;
1672 }
1673 
va_format(char * buf,char * end,struct va_format * va_fmt,struct printf_spec spec,const char * fmt)1674 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1675 		       struct printf_spec spec, const char *fmt)
1676 {
1677 	va_list va;
1678 
1679 	if (check_pointer(&buf, end, va_fmt, spec))
1680 		return buf;
1681 
1682 	va_copy(va, *va_fmt->va);
1683 	buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1684 	va_end(va);
1685 
1686 	return buf;
1687 }
1688 
1689 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1690 char *uuid_string(char *buf, char *end, const u8 *addr,
1691 		  struct printf_spec spec, const char *fmt)
1692 {
1693 	char uuid[UUID_STRING_LEN + 1];
1694 	char *p = uuid;
1695 	int i;
1696 	const u8 *index = uuid_index;
1697 	bool uc = false;
1698 
1699 	if (check_pointer(&buf, end, addr, spec))
1700 		return buf;
1701 
1702 	switch (*(++fmt)) {
1703 	case 'L':
1704 		uc = true;
1705 		fallthrough;
1706 	case 'l':
1707 		index = guid_index;
1708 		break;
1709 	case 'B':
1710 		uc = true;
1711 		break;
1712 	}
1713 
1714 	for (i = 0; i < 16; i++) {
1715 		if (uc)
1716 			p = hex_byte_pack_upper(p, addr[index[i]]);
1717 		else
1718 			p = hex_byte_pack(p, addr[index[i]]);
1719 		switch (i) {
1720 		case 3:
1721 		case 5:
1722 		case 7:
1723 		case 9:
1724 			*p++ = '-';
1725 			break;
1726 		}
1727 	}
1728 
1729 	*p = 0;
1730 
1731 	return string_nocheck(buf, end, uuid, spec);
1732 }
1733 
1734 static noinline_for_stack
netdev_bits(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1735 char *netdev_bits(char *buf, char *end, const void *addr,
1736 		  struct printf_spec spec,  const char *fmt)
1737 {
1738 	unsigned long long num;
1739 	int size;
1740 
1741 	if (check_pointer(&buf, end, addr, spec))
1742 		return buf;
1743 
1744 	switch (fmt[1]) {
1745 	case 'F':
1746 		num = *(const netdev_features_t *)addr;
1747 		size = sizeof(netdev_features_t);
1748 		break;
1749 	default:
1750 		return error_string(buf, end, "(%pN?)", spec);
1751 	}
1752 
1753 	return special_hex_number(buf, end, num, size);
1754 }
1755 
1756 static noinline_for_stack
fourcc_string(char * buf,char * end,const u32 * fourcc,struct printf_spec spec,const char * fmt)1757 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1758 		    struct printf_spec spec, const char *fmt)
1759 {
1760 	char output[sizeof("0123 little-endian (0x01234567)")];
1761 	char *p = output;
1762 	unsigned int i;
1763 	u32 orig, val;
1764 
1765 	if (fmt[1] != 'c' || fmt[2] != 'c')
1766 		return error_string(buf, end, "(%p4?)", spec);
1767 
1768 	if (check_pointer(&buf, end, fourcc, spec))
1769 		return buf;
1770 
1771 	orig = get_unaligned(fourcc);
1772 	val = orig & ~BIT(31);
1773 
1774 	for (i = 0; i < sizeof(u32); i++) {
1775 		unsigned char c = val >> (i * 8);
1776 
1777 		/* Print non-control ASCII characters as-is, dot otherwise */
1778 		*p++ = isascii(c) && isprint(c) ? c : '.';
1779 	}
1780 
1781 	*p++ = ' ';
1782 	strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
1783 	p += strlen(p);
1784 
1785 	*p++ = ' ';
1786 	*p++ = '(';
1787 	p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1788 	*p++ = ')';
1789 	*p = '\0';
1790 
1791 	return string(buf, end, output, spec);
1792 }
1793 
1794 static noinline_for_stack
address_val(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1795 char *address_val(char *buf, char *end, const void *addr,
1796 		  struct printf_spec spec, const char *fmt)
1797 {
1798 	unsigned long long num;
1799 	int size;
1800 
1801 	if (check_pointer(&buf, end, addr, spec))
1802 		return buf;
1803 
1804 	switch (fmt[1]) {
1805 	case 'd':
1806 		num = *(const dma_addr_t *)addr;
1807 		size = sizeof(dma_addr_t);
1808 		break;
1809 	case 'p':
1810 	default:
1811 		num = *(const phys_addr_t *)addr;
1812 		size = sizeof(phys_addr_t);
1813 		break;
1814 	}
1815 
1816 	return special_hex_number(buf, end, num, size);
1817 }
1818 
1819 static noinline_for_stack
date_str(char * buf,char * end,const struct rtc_time * tm,bool r)1820 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1821 {
1822 	int year = tm->tm_year + (r ? 0 : 1900);
1823 	int mon = tm->tm_mon + (r ? 0 : 1);
1824 
1825 	buf = number(buf, end, year, default_dec04_spec);
1826 	if (buf < end)
1827 		*buf = '-';
1828 	buf++;
1829 
1830 	buf = number(buf, end, mon, default_dec02_spec);
1831 	if (buf < end)
1832 		*buf = '-';
1833 	buf++;
1834 
1835 	return number(buf, end, tm->tm_mday, default_dec02_spec);
1836 }
1837 
1838 static noinline_for_stack
time_str(char * buf,char * end,const struct rtc_time * tm,bool r)1839 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1840 {
1841 	buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1842 	if (buf < end)
1843 		*buf = ':';
1844 	buf++;
1845 
1846 	buf = number(buf, end, tm->tm_min, default_dec02_spec);
1847 	if (buf < end)
1848 		*buf = ':';
1849 	buf++;
1850 
1851 	return number(buf, end, tm->tm_sec, default_dec02_spec);
1852 }
1853 
1854 static noinline_for_stack
rtc_str(char * buf,char * end,const struct rtc_time * tm,struct printf_spec spec,const char * fmt)1855 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1856 	      struct printf_spec spec, const char *fmt)
1857 {
1858 	bool have_t = true, have_d = true;
1859 	bool raw = false, iso8601_separator = true;
1860 	bool found = true;
1861 	int count = 2;
1862 
1863 	if (check_pointer(&buf, end, tm, spec))
1864 		return buf;
1865 
1866 	switch (fmt[count]) {
1867 	case 'd':
1868 		have_t = false;
1869 		count++;
1870 		break;
1871 	case 't':
1872 		have_d = false;
1873 		count++;
1874 		break;
1875 	}
1876 
1877 	do {
1878 		switch (fmt[count++]) {
1879 		case 'r':
1880 			raw = true;
1881 			break;
1882 		case 's':
1883 			iso8601_separator = false;
1884 			break;
1885 		default:
1886 			found = false;
1887 			break;
1888 		}
1889 	} while (found);
1890 
1891 	if (have_d)
1892 		buf = date_str(buf, end, tm, raw);
1893 	if (have_d && have_t) {
1894 		if (buf < end)
1895 			*buf = iso8601_separator ? 'T' : ' ';
1896 		buf++;
1897 	}
1898 	if (have_t)
1899 		buf = time_str(buf, end, tm, raw);
1900 
1901 	return buf;
1902 }
1903 
1904 static noinline_for_stack
time64_str(char * buf,char * end,const time64_t time,struct printf_spec spec,const char * fmt)1905 char *time64_str(char *buf, char *end, const time64_t time,
1906 		 struct printf_spec spec, const char *fmt)
1907 {
1908 	struct rtc_time rtc_time;
1909 	struct tm tm;
1910 
1911 	time64_to_tm(time, 0, &tm);
1912 
1913 	rtc_time.tm_sec = tm.tm_sec;
1914 	rtc_time.tm_min = tm.tm_min;
1915 	rtc_time.tm_hour = tm.tm_hour;
1916 	rtc_time.tm_mday = tm.tm_mday;
1917 	rtc_time.tm_mon = tm.tm_mon;
1918 	rtc_time.tm_year = tm.tm_year;
1919 	rtc_time.tm_wday = tm.tm_wday;
1920 	rtc_time.tm_yday = tm.tm_yday;
1921 
1922 	rtc_time.tm_isdst = 0;
1923 
1924 	return rtc_str(buf, end, &rtc_time, spec, fmt);
1925 }
1926 
1927 static noinline_for_stack
time_and_date(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)1928 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1929 		    const char *fmt)
1930 {
1931 	switch (fmt[1]) {
1932 	case 'R':
1933 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1934 	case 'T':
1935 		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1936 	default:
1937 		return error_string(buf, end, "(%pt?)", spec);
1938 	}
1939 }
1940 
1941 static noinline_for_stack
clock(char * buf,char * end,struct clk * clk,struct printf_spec spec,const char * fmt)1942 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1943 	    const char *fmt)
1944 {
1945 	if (!IS_ENABLED(CONFIG_HAVE_CLK))
1946 		return error_string(buf, end, "(%pC?)", spec);
1947 
1948 	if (check_pointer(&buf, end, clk, spec))
1949 		return buf;
1950 
1951 	switch (fmt[1]) {
1952 	case 'n':
1953 	default:
1954 #ifdef CONFIG_COMMON_CLK
1955 		return string(buf, end, __clk_get_name(clk), spec);
1956 #else
1957 		return ptr_to_id(buf, end, clk, spec);
1958 #endif
1959 	}
1960 }
1961 
1962 static
format_flags(char * buf,char * end,unsigned long flags,const struct trace_print_flags * names)1963 char *format_flags(char *buf, char *end, unsigned long flags,
1964 					const struct trace_print_flags *names)
1965 {
1966 	unsigned long mask;
1967 
1968 	for ( ; flags && names->name; names++) {
1969 		mask = names->mask;
1970 		if ((flags & mask) != mask)
1971 			continue;
1972 
1973 		buf = string(buf, end, names->name, default_str_spec);
1974 
1975 		flags &= ~mask;
1976 		if (flags) {
1977 			if (buf < end)
1978 				*buf = '|';
1979 			buf++;
1980 		}
1981 	}
1982 
1983 	if (flags)
1984 		buf = number(buf, end, flags, default_flag_spec);
1985 
1986 	return buf;
1987 }
1988 
1989 struct page_flags_fields {
1990 	int width;
1991 	int shift;
1992 	int mask;
1993 	const struct printf_spec *spec;
1994 	const char *name;
1995 };
1996 
1997 static const struct page_flags_fields pff[] = {
1998 	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
1999 	 &default_dec_spec, "section"},
2000 	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2001 	 &default_dec_spec, "node"},
2002 	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2003 	 &default_dec_spec, "zone"},
2004 	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2005 	 &default_flag_spec, "lastcpupid"},
2006 	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2007 	 &default_flag_spec, "kasantag"},
2008 };
2009 
2010 static
format_page_flags(char * buf,char * end,unsigned long flags)2011 char *format_page_flags(char *buf, char *end, unsigned long flags)
2012 {
2013 	unsigned long main_flags = flags & PAGEFLAGS_MASK;
2014 	bool append = false;
2015 	int i;
2016 
2017 	buf = number(buf, end, flags, default_flag_spec);
2018 	if (buf < end)
2019 		*buf = '(';
2020 	buf++;
2021 
2022 	/* Page flags from the main area. */
2023 	if (main_flags) {
2024 		buf = format_flags(buf, end, main_flags, pageflag_names);
2025 		append = true;
2026 	}
2027 
2028 	/* Page flags from the fields area */
2029 	for (i = 0; i < ARRAY_SIZE(pff); i++) {
2030 		/* Skip undefined fields. */
2031 		if (!pff[i].width)
2032 			continue;
2033 
2034 		/* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2035 		if (append) {
2036 			if (buf < end)
2037 				*buf = '|';
2038 			buf++;
2039 		}
2040 
2041 		buf = string(buf, end, pff[i].name, default_str_spec);
2042 		if (buf < end)
2043 			*buf = '=';
2044 		buf++;
2045 		buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2046 			     *pff[i].spec);
2047 
2048 		append = true;
2049 	}
2050 	if (buf < end)
2051 		*buf = ')';
2052 	buf++;
2053 
2054 	return buf;
2055 }
2056 
2057 static noinline_for_stack
flags_string(char * buf,char * end,void * flags_ptr,struct printf_spec spec,const char * fmt)2058 char *flags_string(char *buf, char *end, void *flags_ptr,
2059 		   struct printf_spec spec, const char *fmt)
2060 {
2061 	unsigned long flags;
2062 	const struct trace_print_flags *names;
2063 
2064 	if (check_pointer(&buf, end, flags_ptr, spec))
2065 		return buf;
2066 
2067 	switch (fmt[1]) {
2068 	case 'p':
2069 		return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2070 	case 'v':
2071 		flags = *(unsigned long *)flags_ptr;
2072 		names = vmaflag_names;
2073 		break;
2074 	case 'g':
2075 		flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2076 		names = gfpflag_names;
2077 		break;
2078 	default:
2079 		return error_string(buf, end, "(%pG?)", spec);
2080 	}
2081 
2082 	return format_flags(buf, end, flags, names);
2083 }
2084 
2085 static noinline_for_stack
fwnode_full_name_string(struct fwnode_handle * fwnode,char * buf,char * end)2086 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2087 			      char *end)
2088 {
2089 	int depth;
2090 
2091 	/* Loop starting from the root node to the current node. */
2092 	for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2093 		/*
2094 		 * Only get a reference for other nodes (i.e. parent nodes).
2095 		 * fwnode refcount may be 0 here.
2096 		 */
2097 		struct fwnode_handle *__fwnode = depth ?
2098 			fwnode_get_nth_parent(fwnode, depth) : fwnode;
2099 
2100 		buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2101 			     default_str_spec);
2102 		buf = string(buf, end, fwnode_get_name(__fwnode),
2103 			     default_str_spec);
2104 
2105 		if (depth)
2106 			fwnode_handle_put(__fwnode);
2107 	}
2108 
2109 	return buf;
2110 }
2111 
2112 static noinline_for_stack
device_node_string(char * buf,char * end,struct device_node * dn,struct printf_spec spec,const char * fmt)2113 char *device_node_string(char *buf, char *end, struct device_node *dn,
2114 			 struct printf_spec spec, const char *fmt)
2115 {
2116 	char tbuf[sizeof("xxxx") + 1];
2117 	const char *p;
2118 	int ret;
2119 	char *buf_start = buf;
2120 	struct property *prop;
2121 	bool has_mult, pass;
2122 
2123 	struct printf_spec str_spec = spec;
2124 	str_spec.field_width = -1;
2125 
2126 	if (fmt[0] != 'F')
2127 		return error_string(buf, end, "(%pO?)", spec);
2128 
2129 	if (!IS_ENABLED(CONFIG_OF))
2130 		return error_string(buf, end, "(%pOF?)", spec);
2131 
2132 	if (check_pointer(&buf, end, dn, spec))
2133 		return buf;
2134 
2135 	/* simple case without anything any more format specifiers */
2136 	fmt++;
2137 	if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2138 		fmt = "f";
2139 
2140 	for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2141 		int precision;
2142 		if (pass) {
2143 			if (buf < end)
2144 				*buf = ':';
2145 			buf++;
2146 		}
2147 
2148 		switch (*fmt) {
2149 		case 'f':	/* full_name */
2150 			buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2151 						      end);
2152 			break;
2153 		case 'n':	/* name */
2154 			p = fwnode_get_name(of_fwnode_handle(dn));
2155 			precision = str_spec.precision;
2156 			str_spec.precision = strchrnul(p, '@') - p;
2157 			buf = string(buf, end, p, str_spec);
2158 			str_spec.precision = precision;
2159 			break;
2160 		case 'p':	/* phandle */
2161 			buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2162 			break;
2163 		case 'P':	/* path-spec */
2164 			p = fwnode_get_name(of_fwnode_handle(dn));
2165 			if (!p[1])
2166 				p = "/";
2167 			buf = string(buf, end, p, str_spec);
2168 			break;
2169 		case 'F':	/* flags */
2170 			tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2171 			tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2172 			tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2173 			tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2174 			tbuf[4] = 0;
2175 			buf = string_nocheck(buf, end, tbuf, str_spec);
2176 			break;
2177 		case 'c':	/* major compatible string */
2178 			ret = of_property_read_string(dn, "compatible", &p);
2179 			if (!ret)
2180 				buf = string(buf, end, p, str_spec);
2181 			break;
2182 		case 'C':	/* full compatible string */
2183 			has_mult = false;
2184 			of_property_for_each_string(dn, "compatible", prop, p) {
2185 				if (has_mult)
2186 					buf = string_nocheck(buf, end, ",", str_spec);
2187 				buf = string_nocheck(buf, end, "\"", str_spec);
2188 				buf = string(buf, end, p, str_spec);
2189 				buf = string_nocheck(buf, end, "\"", str_spec);
2190 
2191 				has_mult = true;
2192 			}
2193 			break;
2194 		default:
2195 			break;
2196 		}
2197 	}
2198 
2199 	return widen_string(buf, buf - buf_start, end, spec);
2200 }
2201 
2202 static noinline_for_stack
fwnode_string(char * buf,char * end,struct fwnode_handle * fwnode,struct printf_spec spec,const char * fmt)2203 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2204 		    struct printf_spec spec, const char *fmt)
2205 {
2206 	struct printf_spec str_spec = spec;
2207 	char *buf_start = buf;
2208 
2209 	str_spec.field_width = -1;
2210 
2211 	if (*fmt != 'w')
2212 		return error_string(buf, end, "(%pf?)", spec);
2213 
2214 	if (check_pointer(&buf, end, fwnode, spec))
2215 		return buf;
2216 
2217 	fmt++;
2218 
2219 	switch (*fmt) {
2220 	case 'P':	/* name */
2221 		buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2222 		break;
2223 	case 'f':	/* full_name */
2224 	default:
2225 		buf = fwnode_full_name_string(fwnode, buf, end);
2226 		break;
2227 	}
2228 
2229 	return widen_string(buf, buf - buf_start, end, spec);
2230 }
2231 
no_hash_pointers_enable(char * str)2232 int __init no_hash_pointers_enable(char *str)
2233 {
2234 	if (no_hash_pointers)
2235 		return 0;
2236 
2237 	no_hash_pointers = true;
2238 
2239 	pr_warn("**********************************************************\n");
2240 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2241 	pr_warn("**                                                      **\n");
2242 	pr_warn("** This system shows unhashed kernel memory addresses   **\n");
2243 	pr_warn("** via the console, logs, and other interfaces. This    **\n");
2244 	pr_warn("** might reduce the security of your system.            **\n");
2245 	pr_warn("**                                                      **\n");
2246 	pr_warn("** If you see this message and you are not debugging    **\n");
2247 	pr_warn("** the kernel, report this immediately to your system   **\n");
2248 	pr_warn("** administrator!                                       **\n");
2249 	pr_warn("**                                                      **\n");
2250 	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
2251 	pr_warn("**********************************************************\n");
2252 
2253 	return 0;
2254 }
2255 early_param("no_hash_pointers", no_hash_pointers_enable);
2256 
2257 /* Used for Rust formatting ('%pA'). */
2258 char *rust_fmt_argument(char *buf, char *end, void *ptr);
2259 
2260 /*
2261  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
2262  * by an extra set of alphanumeric characters that are extended format
2263  * specifiers.
2264  *
2265  * Please update scripts/checkpatch.pl when adding/removing conversion
2266  * characters.  (Search for "check for vsprintf extension").
2267  *
2268  * Right now we handle:
2269  *
2270  * - 'S' For symbolic direct pointers (or function descriptors) with offset
2271  * - 's' For symbolic direct pointers (or function descriptors) without offset
2272  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2273  * - 'S[R]b' as above with module build ID (for use in backtraces)
2274  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2275  *	    %ps and %pS. Be careful when re-using these specifiers.
2276  * - 'B' For backtraced symbolic direct pointers with offset
2277  * - 'Bb' as above with module build ID (for use in backtraces)
2278  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2279  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2280  * - 'b[l]' For a bitmap, the number of bits is determined by the field
2281  *       width which must be explicitly specified either as part of the
2282  *       format string '%32b[l]' or through '%*b[l]', [l] selects
2283  *       range-list format instead of hex format
2284  * - 'M' For a 6-byte MAC address, it prints the address in the
2285  *       usual colon-separated hex notation
2286  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2287  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2288  *       with a dash-separated hex notation
2289  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2290  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2291  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2292  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
2293  *       [S][pfs]
2294  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2295  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2296  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2297  *       IPv6 omits the colons (01020304...0f)
2298  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2299  *       [S][pfs]
2300  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2301  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2302  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2303  * - 'I[6S]c' for IPv6 addresses printed as specified by
2304  *       https://tools.ietf.org/html/rfc5952
2305  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2306  *                of the following flags (see string_escape_mem() for the
2307  *                details):
2308  *                  a - ESCAPE_ANY
2309  *                  c - ESCAPE_SPECIAL
2310  *                  h - ESCAPE_HEX
2311  *                  n - ESCAPE_NULL
2312  *                  o - ESCAPE_OCTAL
2313  *                  p - ESCAPE_NP
2314  *                  s - ESCAPE_SPACE
2315  *                By default ESCAPE_ANY_NP is used.
2316  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2317  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2318  *       Options for %pU are:
2319  *         b big endian lower case hex (default)
2320  *         B big endian UPPER case hex
2321  *         l little endian lower case hex
2322  *         L little endian UPPER case hex
2323  *           big endian output byte order is:
2324  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2325  *           little endian output byte order is:
2326  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2327  * - 'V' For a struct va_format which contains a format string * and va_list *,
2328  *       call vsnprintf(->format, *->va_list).
2329  *       Implements a "recursive vsnprintf".
2330  *       Do not use this feature without some mechanism to verify the
2331  *       correctness of the format string and va_list arguments.
2332  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2333  *       Use only for procfs, sysfs and similar files, not printk(); please
2334  *       read the documentation (path below) first.
2335  * - 'NF' For a netdev_features_t
2336  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2337  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2338  *            a certain separator (' ' by default):
2339  *              C colon
2340  *              D dash
2341  *              N no separator
2342  *            The maximum supported length is 64 bytes of the input. Consider
2343  *            to use print_hex_dump() for the larger input.
2344  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2345  *           (default assumed to be phys_addr_t, passed by reference)
2346  * - 'd[234]' For a dentry name (optionally 2-4 last components)
2347  * - 'D[234]' Same as 'd' but for a struct file
2348  * - 'g' For block_device name (gendisk + partition number)
2349  * - 't[RT][dt][r][s]' For time and date as represented by:
2350  *      R    struct rtc_time
2351  *      T    time64_t
2352  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2353  *       (legacy clock framework) of the clock
2354  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2355  *        (legacy clock framework) of the clock
2356  * - 'G' For flags to be printed as a collection of symbolic strings that would
2357  *       construct the specific value. Supported flags given by option:
2358  *       p page flags (see struct page) given as pointer to unsigned long
2359  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2360  *       v vma flags (VM_*) given as pointer to unsigned long
2361  * - 'OF[fnpPcCF]'  For a device tree object
2362  *                  Without any optional arguments prints the full_name
2363  *                  f device node full_name
2364  *                  n device node name
2365  *                  p device node phandle
2366  *                  P device node path spec (name + @unit)
2367  *                  F device node flags
2368  *                  c major compatible string
2369  *                  C full compatible string
2370  * - 'fw[fP]'	For a firmware node (struct fwnode_handle) pointer
2371  *		Without an option prints the full name of the node
2372  *		f full name
2373  *		P node name, including a possible unit address
2374  * - 'x' For printing the address unmodified. Equivalent to "%lx".
2375  *       Please read the documentation (path below) before using!
2376  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2377  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2378  *           or user (u) memory to probe, and:
2379  *              s a string, equivalent to "%s" on direct vsnprintf() use
2380  *
2381  * ** When making changes please also update:
2382  *	Documentation/core-api/printk-formats.rst
2383  *
2384  * Note: The default behaviour (unadorned %p) is to hash the address,
2385  * rendering it useful as a unique identifier.
2386  *
2387  * There is also a '%pA' format specifier, but it is only intended to be used
2388  * from Rust code to format core::fmt::Arguments. Do *not* use it from C.
2389  * See rust/kernel/print.rs for details.
2390  */
2391 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2392 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2393 	      struct printf_spec spec)
2394 {
2395 	switch (*fmt) {
2396 	case 'S':
2397 	case 's':
2398 		ptr = dereference_symbol_descriptor(ptr);
2399 		fallthrough;
2400 	case 'B':
2401 		return symbol_string(buf, end, ptr, spec, fmt);
2402 	case 'R':
2403 	case 'r':
2404 		return resource_string(buf, end, ptr, spec, fmt);
2405 	case 'h':
2406 		return hex_string(buf, end, ptr, spec, fmt);
2407 	case 'b':
2408 		switch (fmt[1]) {
2409 		case 'l':
2410 			return bitmap_list_string(buf, end, ptr, spec, fmt);
2411 		default:
2412 			return bitmap_string(buf, end, ptr, spec, fmt);
2413 		}
2414 	case 'M':			/* Colon separated: 00:01:02:03:04:05 */
2415 	case 'm':			/* Contiguous: 000102030405 */
2416 					/* [mM]F (FDDI) */
2417 					/* [mM]R (Reverse order; Bluetooth) */
2418 		return mac_address_string(buf, end, ptr, spec, fmt);
2419 	case 'I':			/* Formatted IP supported
2420 					 * 4:	1.2.3.4
2421 					 * 6:	0001:0203:...:0708
2422 					 * 6c:	1::708 or 1::1.2.3.4
2423 					 */
2424 	case 'i':			/* Contiguous:
2425 					 * 4:	001.002.003.004
2426 					 * 6:   000102...0f
2427 					 */
2428 		return ip_addr_string(buf, end, ptr, spec, fmt);
2429 	case 'E':
2430 		return escaped_string(buf, end, ptr, spec, fmt);
2431 	case 'U':
2432 		return uuid_string(buf, end, ptr, spec, fmt);
2433 	case 'V':
2434 		return va_format(buf, end, ptr, spec, fmt);
2435 	case 'K':
2436 		return restricted_pointer(buf, end, ptr, spec);
2437 	case 'N':
2438 		return netdev_bits(buf, end, ptr, spec, fmt);
2439 	case '4':
2440 		return fourcc_string(buf, end, ptr, spec, fmt);
2441 	case 'a':
2442 		return address_val(buf, end, ptr, spec, fmt);
2443 	case 'd':
2444 		return dentry_name(buf, end, ptr, spec, fmt);
2445 	case 't':
2446 		return time_and_date(buf, end, ptr, spec, fmt);
2447 	case 'C':
2448 		return clock(buf, end, ptr, spec, fmt);
2449 	case 'D':
2450 		return file_dentry_name(buf, end, ptr, spec, fmt);
2451 #ifdef CONFIG_BLOCK
2452 	case 'g':
2453 		return bdev_name(buf, end, ptr, spec, fmt);
2454 #endif
2455 
2456 	case 'G':
2457 		return flags_string(buf, end, ptr, spec, fmt);
2458 	case 'O':
2459 		return device_node_string(buf, end, ptr, spec, fmt + 1);
2460 	case 'f':
2461 		return fwnode_string(buf, end, ptr, spec, fmt + 1);
2462 	case 'A':
2463 		if (!IS_ENABLED(CONFIG_RUST)) {
2464 			WARN_ONCE(1, "Please remove %%pA from non-Rust code\n");
2465 			return error_string(buf, end, "(%pA?)", spec);
2466 		}
2467 		return rust_fmt_argument(buf, end, ptr);
2468 	case 'x':
2469 		return pointer_string(buf, end, ptr, spec);
2470 	case 'e':
2471 		/* %pe with a non-ERR_PTR gets treated as plain %p */
2472 		if (!IS_ERR(ptr))
2473 			return default_pointer(buf, end, ptr, spec);
2474 		return err_ptr(buf, end, ptr, spec);
2475 	case 'u':
2476 	case 'k':
2477 		switch (fmt[1]) {
2478 		case 's':
2479 			return string(buf, end, ptr, spec);
2480 		default:
2481 			return error_string(buf, end, "(einval)", spec);
2482 		}
2483 	default:
2484 		return default_pointer(buf, end, ptr, spec);
2485 	}
2486 }
2487 
2488 /*
2489  * Helper function to decode printf style format.
2490  * Each call decode a token from the format and return the
2491  * number of characters read (or likely the delta where it wants
2492  * to go on the next call).
2493  * The decoded token is returned through the parameters
2494  *
2495  * 'h', 'l', or 'L' for integer fields
2496  * 'z' support added 23/7/1999 S.H.
2497  * 'z' changed to 'Z' --davidm 1/25/99
2498  * 'Z' changed to 'z' --adobriyan 2017-01-25
2499  * 't' added for ptrdiff_t
2500  *
2501  * @fmt: the format string
2502  * @type of the token returned
2503  * @flags: various flags such as +, -, # tokens..
2504  * @field_width: overwritten width
2505  * @base: base of the number (octal, hex, ...)
2506  * @precision: precision of a number
2507  * @qualifier: qualifier of a number (long, size_t, ...)
2508  */
2509 static noinline_for_stack
format_decode(const char * fmt,struct printf_spec * spec)2510 int format_decode(const char *fmt, struct printf_spec *spec)
2511 {
2512 	const char *start = fmt;
2513 	char qualifier;
2514 
2515 	/* we finished early by reading the field width */
2516 	if (spec->type == FORMAT_TYPE_WIDTH) {
2517 		if (spec->field_width < 0) {
2518 			spec->field_width = -spec->field_width;
2519 			spec->flags |= LEFT;
2520 		}
2521 		spec->type = FORMAT_TYPE_NONE;
2522 		goto precision;
2523 	}
2524 
2525 	/* we finished early by reading the precision */
2526 	if (spec->type == FORMAT_TYPE_PRECISION) {
2527 		if (spec->precision < 0)
2528 			spec->precision = 0;
2529 
2530 		spec->type = FORMAT_TYPE_NONE;
2531 		goto qualifier;
2532 	}
2533 
2534 	/* By default */
2535 	spec->type = FORMAT_TYPE_NONE;
2536 
2537 	for (; *fmt ; ++fmt) {
2538 		if (*fmt == '%')
2539 			break;
2540 	}
2541 
2542 	/* Return the current non-format string */
2543 	if (fmt != start || !*fmt)
2544 		return fmt - start;
2545 
2546 	/* Process flags */
2547 	spec->flags = 0;
2548 
2549 	while (1) { /* this also skips first '%' */
2550 		bool found = true;
2551 
2552 		++fmt;
2553 
2554 		switch (*fmt) {
2555 		case '-': spec->flags |= LEFT;    break;
2556 		case '+': spec->flags |= PLUS;    break;
2557 		case ' ': spec->flags |= SPACE;   break;
2558 		case '#': spec->flags |= SPECIAL; break;
2559 		case '0': spec->flags |= ZEROPAD; break;
2560 		default:  found = false;
2561 		}
2562 
2563 		if (!found)
2564 			break;
2565 	}
2566 
2567 	/* get field width */
2568 	spec->field_width = -1;
2569 
2570 	if (isdigit(*fmt))
2571 		spec->field_width = skip_atoi(&fmt);
2572 	else if (*fmt == '*') {
2573 		/* it's the next argument */
2574 		spec->type = FORMAT_TYPE_WIDTH;
2575 		return ++fmt - start;
2576 	}
2577 
2578 precision:
2579 	/* get the precision */
2580 	spec->precision = -1;
2581 	if (*fmt == '.') {
2582 		++fmt;
2583 		if (isdigit(*fmt)) {
2584 			spec->precision = skip_atoi(&fmt);
2585 			if (spec->precision < 0)
2586 				spec->precision = 0;
2587 		} else if (*fmt == '*') {
2588 			/* it's the next argument */
2589 			spec->type = FORMAT_TYPE_PRECISION;
2590 			return ++fmt - start;
2591 		}
2592 	}
2593 
2594 qualifier:
2595 	/* get the conversion qualifier */
2596 	qualifier = 0;
2597 	if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2598 	    *fmt == 'z' || *fmt == 't') {
2599 		qualifier = *fmt++;
2600 		if (unlikely(qualifier == *fmt)) {
2601 			if (qualifier == 'l') {
2602 				qualifier = 'L';
2603 				++fmt;
2604 			} else if (qualifier == 'h') {
2605 				qualifier = 'H';
2606 				++fmt;
2607 			}
2608 		}
2609 	}
2610 
2611 	/* default base */
2612 	spec->base = 10;
2613 	switch (*fmt) {
2614 	case 'c':
2615 		spec->type = FORMAT_TYPE_CHAR;
2616 		return ++fmt - start;
2617 
2618 	case 's':
2619 		spec->type = FORMAT_TYPE_STR;
2620 		return ++fmt - start;
2621 
2622 	case 'p':
2623 		spec->type = FORMAT_TYPE_PTR;
2624 		return ++fmt - start;
2625 
2626 	case '%':
2627 		spec->type = FORMAT_TYPE_PERCENT_CHAR;
2628 		return ++fmt - start;
2629 
2630 	/* integer number formats - set up the flags and "break" */
2631 	case 'o':
2632 		spec->base = 8;
2633 		break;
2634 
2635 	case 'x':
2636 		spec->flags |= SMALL;
2637 		fallthrough;
2638 
2639 	case 'X':
2640 		spec->base = 16;
2641 		break;
2642 
2643 	case 'd':
2644 	case 'i':
2645 		spec->flags |= SIGN;
2646 		break;
2647 	case 'u':
2648 		break;
2649 
2650 	case 'n':
2651 		/*
2652 		 * Since %n poses a greater security risk than
2653 		 * utility, treat it as any other invalid or
2654 		 * unsupported format specifier.
2655 		 */
2656 		fallthrough;
2657 
2658 	default:
2659 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2660 		spec->type = FORMAT_TYPE_INVALID;
2661 		return fmt - start;
2662 	}
2663 
2664 	if (qualifier == 'L')
2665 		spec->type = FORMAT_TYPE_LONG_LONG;
2666 	else if (qualifier == 'l') {
2667 		BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2668 		spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2669 	} else if (qualifier == 'z') {
2670 		spec->type = FORMAT_TYPE_SIZE_T;
2671 	} else if (qualifier == 't') {
2672 		spec->type = FORMAT_TYPE_PTRDIFF;
2673 	} else if (qualifier == 'H') {
2674 		BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2675 		spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2676 	} else if (qualifier == 'h') {
2677 		BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2678 		spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2679 	} else {
2680 		BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2681 		spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2682 	}
2683 
2684 	return ++fmt - start;
2685 }
2686 
2687 static void
set_field_width(struct printf_spec * spec,int width)2688 set_field_width(struct printf_spec *spec, int width)
2689 {
2690 	spec->field_width = width;
2691 	if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2692 		spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2693 	}
2694 }
2695 
2696 static void
set_precision(struct printf_spec * spec,int prec)2697 set_precision(struct printf_spec *spec, int prec)
2698 {
2699 	spec->precision = prec;
2700 	if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2701 		spec->precision = clamp(prec, 0, PRECISION_MAX);
2702 	}
2703 }
2704 
2705 /**
2706  * vsnprintf - Format a string and place it in a buffer
2707  * @buf: The buffer to place the result into
2708  * @size: The size of the buffer, including the trailing null space
2709  * @fmt: The format string to use
2710  * @args: Arguments for the format string
2711  *
2712  * This function generally follows C99 vsnprintf, but has some
2713  * extensions and a few limitations:
2714  *
2715  *  - ``%n`` is unsupported
2716  *  - ``%p*`` is handled by pointer()
2717  *
2718  * See pointer() or Documentation/core-api/printk-formats.rst for more
2719  * extensive description.
2720  *
2721  * **Please update the documentation in both places when making changes**
2722  *
2723  * The return value is the number of characters which would
2724  * be generated for the given input, excluding the trailing
2725  * '\0', as per ISO C99. If you want to have the exact
2726  * number of characters written into @buf as return value
2727  * (not including the trailing '\0'), use vscnprintf(). If the
2728  * return is greater than or equal to @size, the resulting
2729  * string is truncated.
2730  *
2731  * If you're not already dealing with a va_list consider using snprintf().
2732  */
vsnprintf(char * buf,size_t size,const char * fmt,va_list args)2733 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2734 {
2735 	unsigned long long num;
2736 	char *str, *end;
2737 	struct printf_spec spec = {0};
2738 
2739 	/* Reject out-of-range values early.  Large positive sizes are
2740 	   used for unknown buffer sizes. */
2741 	if (WARN_ON_ONCE(size > INT_MAX))
2742 		return 0;
2743 
2744 	str = buf;
2745 	end = buf + size;
2746 
2747 	/* Make sure end is always >= buf */
2748 	if (end < buf) {
2749 		end = ((void *)-1);
2750 		size = end - buf;
2751 	}
2752 
2753 	while (*fmt) {
2754 		const char *old_fmt = fmt;
2755 		int read = format_decode(fmt, &spec);
2756 
2757 		fmt += read;
2758 
2759 		switch (spec.type) {
2760 		case FORMAT_TYPE_NONE: {
2761 			int copy = read;
2762 			if (str < end) {
2763 				if (copy > end - str)
2764 					copy = end - str;
2765 				memcpy(str, old_fmt, copy);
2766 			}
2767 			str += read;
2768 			break;
2769 		}
2770 
2771 		case FORMAT_TYPE_WIDTH:
2772 			set_field_width(&spec, va_arg(args, int));
2773 			break;
2774 
2775 		case FORMAT_TYPE_PRECISION:
2776 			set_precision(&spec, va_arg(args, int));
2777 			break;
2778 
2779 		case FORMAT_TYPE_CHAR: {
2780 			char c;
2781 
2782 			if (!(spec.flags & LEFT)) {
2783 				while (--spec.field_width > 0) {
2784 					if (str < end)
2785 						*str = ' ';
2786 					++str;
2787 
2788 				}
2789 			}
2790 			c = (unsigned char) va_arg(args, int);
2791 			if (str < end)
2792 				*str = c;
2793 			++str;
2794 			while (--spec.field_width > 0) {
2795 				if (str < end)
2796 					*str = ' ';
2797 				++str;
2798 			}
2799 			break;
2800 		}
2801 
2802 		case FORMAT_TYPE_STR:
2803 			str = string(str, end, va_arg(args, char *), spec);
2804 			break;
2805 
2806 		case FORMAT_TYPE_PTR:
2807 			str = pointer(fmt, str, end, va_arg(args, void *),
2808 				      spec);
2809 			while (isalnum(*fmt))
2810 				fmt++;
2811 			break;
2812 
2813 		case FORMAT_TYPE_PERCENT_CHAR:
2814 			if (str < end)
2815 				*str = '%';
2816 			++str;
2817 			break;
2818 
2819 		case FORMAT_TYPE_INVALID:
2820 			/*
2821 			 * Presumably the arguments passed gcc's type
2822 			 * checking, but there is no safe or sane way
2823 			 * for us to continue parsing the format and
2824 			 * fetching from the va_list; the remaining
2825 			 * specifiers and arguments would be out of
2826 			 * sync.
2827 			 */
2828 			goto out;
2829 
2830 		default:
2831 			switch (spec.type) {
2832 			case FORMAT_TYPE_LONG_LONG:
2833 				num = va_arg(args, long long);
2834 				break;
2835 			case FORMAT_TYPE_ULONG:
2836 				num = va_arg(args, unsigned long);
2837 				break;
2838 			case FORMAT_TYPE_LONG:
2839 				num = va_arg(args, long);
2840 				break;
2841 			case FORMAT_TYPE_SIZE_T:
2842 				if (spec.flags & SIGN)
2843 					num = va_arg(args, ssize_t);
2844 				else
2845 					num = va_arg(args, size_t);
2846 				break;
2847 			case FORMAT_TYPE_PTRDIFF:
2848 				num = va_arg(args, ptrdiff_t);
2849 				break;
2850 			case FORMAT_TYPE_UBYTE:
2851 				num = (unsigned char) va_arg(args, int);
2852 				break;
2853 			case FORMAT_TYPE_BYTE:
2854 				num = (signed char) va_arg(args, int);
2855 				break;
2856 			case FORMAT_TYPE_USHORT:
2857 				num = (unsigned short) va_arg(args, int);
2858 				break;
2859 			case FORMAT_TYPE_SHORT:
2860 				num = (short) va_arg(args, int);
2861 				break;
2862 			case FORMAT_TYPE_INT:
2863 				num = (int) va_arg(args, int);
2864 				break;
2865 			default:
2866 				num = va_arg(args, unsigned int);
2867 			}
2868 
2869 			str = number(str, end, num, spec);
2870 		}
2871 	}
2872 
2873 out:
2874 	if (size > 0) {
2875 		if (str < end)
2876 			*str = '\0';
2877 		else
2878 			end[-1] = '\0';
2879 	}
2880 
2881 	/* the trailing null byte doesn't count towards the total */
2882 	return str-buf;
2883 
2884 }
2885 EXPORT_SYMBOL(vsnprintf);
2886 
2887 /**
2888  * vscnprintf - Format a string and place it in a buffer
2889  * @buf: The buffer to place the result into
2890  * @size: The size of the buffer, including the trailing null space
2891  * @fmt: The format string to use
2892  * @args: Arguments for the format string
2893  *
2894  * The return value is the number of characters which have been written into
2895  * the @buf not including the trailing '\0'. If @size is == 0 the function
2896  * returns 0.
2897  *
2898  * If you're not already dealing with a va_list consider using scnprintf().
2899  *
2900  * See the vsnprintf() documentation for format string extensions over C99.
2901  */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)2902 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2903 {
2904 	int i;
2905 
2906 	if (unlikely(!size))
2907 		return 0;
2908 
2909 	i = vsnprintf(buf, size, fmt, args);
2910 
2911 	if (likely(i < size))
2912 		return i;
2913 
2914 	return size - 1;
2915 }
2916 EXPORT_SYMBOL(vscnprintf);
2917 
2918 /**
2919  * snprintf - Format a string and place it in a buffer
2920  * @buf: The buffer to place the result into
2921  * @size: The size of the buffer, including the trailing null space
2922  * @fmt: The format string to use
2923  * @...: Arguments for the format string
2924  *
2925  * The return value is the number of characters which would be
2926  * generated for the given input, excluding the trailing null,
2927  * as per ISO C99.  If the return is greater than or equal to
2928  * @size, the resulting string is truncated.
2929  *
2930  * See the vsnprintf() documentation for format string extensions over C99.
2931  */
snprintf(char * buf,size_t size,const char * fmt,...)2932 int snprintf(char *buf, size_t size, const char *fmt, ...)
2933 {
2934 	va_list args;
2935 	int i;
2936 
2937 	va_start(args, fmt);
2938 	i = vsnprintf(buf, size, fmt, args);
2939 	va_end(args);
2940 
2941 	return i;
2942 }
2943 EXPORT_SYMBOL(snprintf);
2944 
2945 /**
2946  * scnprintf - Format a string and place it in a buffer
2947  * @buf: The buffer to place the result into
2948  * @size: The size of the buffer, including the trailing null space
2949  * @fmt: The format string to use
2950  * @...: Arguments for the format string
2951  *
2952  * The return value is the number of characters written into @buf not including
2953  * the trailing '\0'. If @size is == 0 the function returns 0.
2954  */
2955 
scnprintf(char * buf,size_t size,const char * fmt,...)2956 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2957 {
2958 	va_list args;
2959 	int i;
2960 
2961 	va_start(args, fmt);
2962 	i = vscnprintf(buf, size, fmt, args);
2963 	va_end(args);
2964 
2965 	return i;
2966 }
2967 EXPORT_SYMBOL(scnprintf);
2968 
2969 /**
2970  * vsprintf - Format a string and place it in a buffer
2971  * @buf: The buffer to place the result into
2972  * @fmt: The format string to use
2973  * @args: Arguments for the format string
2974  *
2975  * The function returns the number of characters written
2976  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2977  * buffer overflows.
2978  *
2979  * If you're not already dealing with a va_list consider using sprintf().
2980  *
2981  * See the vsnprintf() documentation for format string extensions over C99.
2982  */
vsprintf(char * buf,const char * fmt,va_list args)2983 int vsprintf(char *buf, const char *fmt, va_list args)
2984 {
2985 	return vsnprintf(buf, INT_MAX, fmt, args);
2986 }
2987 EXPORT_SYMBOL(vsprintf);
2988 
2989 /**
2990  * sprintf - Format a string and place it in a buffer
2991  * @buf: The buffer to place the result into
2992  * @fmt: The format string to use
2993  * @...: Arguments for the format string
2994  *
2995  * The function returns the number of characters written
2996  * into @buf. Use snprintf() or scnprintf() in order to avoid
2997  * buffer overflows.
2998  *
2999  * See the vsnprintf() documentation for format string extensions over C99.
3000  */
sprintf(char * buf,const char * fmt,...)3001 int sprintf(char *buf, const char *fmt, ...)
3002 {
3003 	va_list args;
3004 	int i;
3005 
3006 	va_start(args, fmt);
3007 	i = vsnprintf(buf, INT_MAX, fmt, args);
3008 	va_end(args);
3009 
3010 	return i;
3011 }
3012 EXPORT_SYMBOL(sprintf);
3013 
3014 #ifdef CONFIG_BINARY_PRINTF
3015 /*
3016  * bprintf service:
3017  * vbin_printf() - VA arguments to binary data
3018  * bstr_printf() - Binary data to text string
3019  */
3020 
3021 /**
3022  * vbin_printf - Parse a format string and place args' binary value in a buffer
3023  * @bin_buf: The buffer to place args' binary value
3024  * @size: The size of the buffer(by words(32bits), not characters)
3025  * @fmt: The format string to use
3026  * @args: Arguments for the format string
3027  *
3028  * The format follows C99 vsnprintf, except %n is ignored, and its argument
3029  * is skipped.
3030  *
3031  * The return value is the number of words(32bits) which would be generated for
3032  * the given input.
3033  *
3034  * NOTE:
3035  * If the return value is greater than @size, the resulting bin_buf is NOT
3036  * valid for bstr_printf().
3037  */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt,va_list args)3038 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3039 {
3040 	struct printf_spec spec = {0};
3041 	char *str, *end;
3042 	int width;
3043 
3044 	str = (char *)bin_buf;
3045 	end = (char *)(bin_buf + size);
3046 
3047 #define save_arg(type)							\
3048 ({									\
3049 	unsigned long long value;					\
3050 	if (sizeof(type) == 8) {					\
3051 		unsigned long long val8;				\
3052 		str = PTR_ALIGN(str, sizeof(u32));			\
3053 		val8 = va_arg(args, unsigned long long);		\
3054 		if (str + sizeof(type) <= end) {			\
3055 			*(u32 *)str = *(u32 *)&val8;			\
3056 			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
3057 		}							\
3058 		value = val8;						\
3059 	} else {							\
3060 		unsigned int val4;					\
3061 		str = PTR_ALIGN(str, sizeof(type));			\
3062 		val4 = va_arg(args, int);				\
3063 		if (str + sizeof(type) <= end)				\
3064 			*(typeof(type) *)str = (type)(long)val4;	\
3065 		value = (unsigned long long)val4;			\
3066 	}								\
3067 	str += sizeof(type);						\
3068 	value;								\
3069 })
3070 
3071 	while (*fmt) {
3072 		int read = format_decode(fmt, &spec);
3073 
3074 		fmt += read;
3075 
3076 		switch (spec.type) {
3077 		case FORMAT_TYPE_NONE:
3078 		case FORMAT_TYPE_PERCENT_CHAR:
3079 			break;
3080 		case FORMAT_TYPE_INVALID:
3081 			goto out;
3082 
3083 		case FORMAT_TYPE_WIDTH:
3084 		case FORMAT_TYPE_PRECISION:
3085 			width = (int)save_arg(int);
3086 			/* Pointers may require the width */
3087 			if (*fmt == 'p')
3088 				set_field_width(&spec, width);
3089 			break;
3090 
3091 		case FORMAT_TYPE_CHAR:
3092 			save_arg(char);
3093 			break;
3094 
3095 		case FORMAT_TYPE_STR: {
3096 			const char *save_str = va_arg(args, char *);
3097 			const char *err_msg;
3098 			size_t len;
3099 
3100 			err_msg = check_pointer_msg(save_str);
3101 			if (err_msg)
3102 				save_str = err_msg;
3103 
3104 			len = strlen(save_str) + 1;
3105 			if (str + len < end)
3106 				memcpy(str, save_str, len);
3107 			str += len;
3108 			break;
3109 		}
3110 
3111 		case FORMAT_TYPE_PTR:
3112 			/* Dereferenced pointers must be done now */
3113 			switch (*fmt) {
3114 			/* Dereference of functions is still OK */
3115 			case 'S':
3116 			case 's':
3117 			case 'x':
3118 			case 'K':
3119 			case 'e':
3120 				save_arg(void *);
3121 				break;
3122 			default:
3123 				if (!isalnum(*fmt)) {
3124 					save_arg(void *);
3125 					break;
3126 				}
3127 				str = pointer(fmt, str, end, va_arg(args, void *),
3128 					      spec);
3129 				if (str + 1 < end)
3130 					*str++ = '\0';
3131 				else
3132 					end[-1] = '\0'; /* Must be nul terminated */
3133 			}
3134 			/* skip all alphanumeric pointer suffixes */
3135 			while (isalnum(*fmt))
3136 				fmt++;
3137 			break;
3138 
3139 		default:
3140 			switch (spec.type) {
3141 
3142 			case FORMAT_TYPE_LONG_LONG:
3143 				save_arg(long long);
3144 				break;
3145 			case FORMAT_TYPE_ULONG:
3146 			case FORMAT_TYPE_LONG:
3147 				save_arg(unsigned long);
3148 				break;
3149 			case FORMAT_TYPE_SIZE_T:
3150 				save_arg(size_t);
3151 				break;
3152 			case FORMAT_TYPE_PTRDIFF:
3153 				save_arg(ptrdiff_t);
3154 				break;
3155 			case FORMAT_TYPE_UBYTE:
3156 			case FORMAT_TYPE_BYTE:
3157 				save_arg(char);
3158 				break;
3159 			case FORMAT_TYPE_USHORT:
3160 			case FORMAT_TYPE_SHORT:
3161 				save_arg(short);
3162 				break;
3163 			default:
3164 				save_arg(int);
3165 			}
3166 		}
3167 	}
3168 
3169 out:
3170 	return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3171 #undef save_arg
3172 }
3173 EXPORT_SYMBOL_GPL(vbin_printf);
3174 
3175 /**
3176  * bstr_printf - Format a string from binary arguments and place it in a buffer
3177  * @buf: The buffer to place the result into
3178  * @size: The size of the buffer, including the trailing null space
3179  * @fmt: The format string to use
3180  * @bin_buf: Binary arguments for the format string
3181  *
3182  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3183  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3184  * a binary buffer that generated by vbin_printf.
3185  *
3186  * The format follows C99 vsnprintf, but has some extensions:
3187  *  see vsnprintf comment for details.
3188  *
3189  * The return value is the number of characters which would
3190  * be generated for the given input, excluding the trailing
3191  * '\0', as per ISO C99. If you want to have the exact
3192  * number of characters written into @buf as return value
3193  * (not including the trailing '\0'), use vscnprintf(). If the
3194  * return is greater than or equal to @size, the resulting
3195  * string is truncated.
3196  */
bstr_printf(char * buf,size_t size,const char * fmt,const u32 * bin_buf)3197 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3198 {
3199 	struct printf_spec spec = {0};
3200 	char *str, *end;
3201 	const char *args = (const char *)bin_buf;
3202 
3203 	if (WARN_ON_ONCE(size > INT_MAX))
3204 		return 0;
3205 
3206 	str = buf;
3207 	end = buf + size;
3208 
3209 #define get_arg(type)							\
3210 ({									\
3211 	typeof(type) value;						\
3212 	if (sizeof(type) == 8) {					\
3213 		args = PTR_ALIGN(args, sizeof(u32));			\
3214 		*(u32 *)&value = *(u32 *)args;				\
3215 		*((u32 *)&value + 1) = *(u32 *)(args + 4);		\
3216 	} else {							\
3217 		args = PTR_ALIGN(args, sizeof(type));			\
3218 		value = *(typeof(type) *)args;				\
3219 	}								\
3220 	args += sizeof(type);						\
3221 	value;								\
3222 })
3223 
3224 	/* Make sure end is always >= buf */
3225 	if (end < buf) {
3226 		end = ((void *)-1);
3227 		size = end - buf;
3228 	}
3229 
3230 	while (*fmt) {
3231 		const char *old_fmt = fmt;
3232 		int read = format_decode(fmt, &spec);
3233 
3234 		fmt += read;
3235 
3236 		switch (spec.type) {
3237 		case FORMAT_TYPE_NONE: {
3238 			int copy = read;
3239 			if (str < end) {
3240 				if (copy > end - str)
3241 					copy = end - str;
3242 				memcpy(str, old_fmt, copy);
3243 			}
3244 			str += read;
3245 			break;
3246 		}
3247 
3248 		case FORMAT_TYPE_WIDTH:
3249 			set_field_width(&spec, get_arg(int));
3250 			break;
3251 
3252 		case FORMAT_TYPE_PRECISION:
3253 			set_precision(&spec, get_arg(int));
3254 			break;
3255 
3256 		case FORMAT_TYPE_CHAR: {
3257 			char c;
3258 
3259 			if (!(spec.flags & LEFT)) {
3260 				while (--spec.field_width > 0) {
3261 					if (str < end)
3262 						*str = ' ';
3263 					++str;
3264 				}
3265 			}
3266 			c = (unsigned char) get_arg(char);
3267 			if (str < end)
3268 				*str = c;
3269 			++str;
3270 			while (--spec.field_width > 0) {
3271 				if (str < end)
3272 					*str = ' ';
3273 				++str;
3274 			}
3275 			break;
3276 		}
3277 
3278 		case FORMAT_TYPE_STR: {
3279 			const char *str_arg = args;
3280 			args += strlen(str_arg) + 1;
3281 			str = string(str, end, (char *)str_arg, spec);
3282 			break;
3283 		}
3284 
3285 		case FORMAT_TYPE_PTR: {
3286 			bool process = false;
3287 			int copy, len;
3288 			/* Non function dereferences were already done */
3289 			switch (*fmt) {
3290 			case 'S':
3291 			case 's':
3292 			case 'x':
3293 			case 'K':
3294 			case 'e':
3295 				process = true;
3296 				break;
3297 			default:
3298 				if (!isalnum(*fmt)) {
3299 					process = true;
3300 					break;
3301 				}
3302 				/* Pointer dereference was already processed */
3303 				if (str < end) {
3304 					len = copy = strlen(args);
3305 					if (copy > end - str)
3306 						copy = end - str;
3307 					memcpy(str, args, copy);
3308 					str += len;
3309 					args += len + 1;
3310 				}
3311 			}
3312 			if (process)
3313 				str = pointer(fmt, str, end, get_arg(void *), spec);
3314 
3315 			while (isalnum(*fmt))
3316 				fmt++;
3317 			break;
3318 		}
3319 
3320 		case FORMAT_TYPE_PERCENT_CHAR:
3321 			if (str < end)
3322 				*str = '%';
3323 			++str;
3324 			break;
3325 
3326 		case FORMAT_TYPE_INVALID:
3327 			goto out;
3328 
3329 		default: {
3330 			unsigned long long num;
3331 
3332 			switch (spec.type) {
3333 
3334 			case FORMAT_TYPE_LONG_LONG:
3335 				num = get_arg(long long);
3336 				break;
3337 			case FORMAT_TYPE_ULONG:
3338 			case FORMAT_TYPE_LONG:
3339 				num = get_arg(unsigned long);
3340 				break;
3341 			case FORMAT_TYPE_SIZE_T:
3342 				num = get_arg(size_t);
3343 				break;
3344 			case FORMAT_TYPE_PTRDIFF:
3345 				num = get_arg(ptrdiff_t);
3346 				break;
3347 			case FORMAT_TYPE_UBYTE:
3348 				num = get_arg(unsigned char);
3349 				break;
3350 			case FORMAT_TYPE_BYTE:
3351 				num = get_arg(signed char);
3352 				break;
3353 			case FORMAT_TYPE_USHORT:
3354 				num = get_arg(unsigned short);
3355 				break;
3356 			case FORMAT_TYPE_SHORT:
3357 				num = get_arg(short);
3358 				break;
3359 			case FORMAT_TYPE_UINT:
3360 				num = get_arg(unsigned int);
3361 				break;
3362 			default:
3363 				num = get_arg(int);
3364 			}
3365 
3366 			str = number(str, end, num, spec);
3367 		} /* default: */
3368 		} /* switch(spec.type) */
3369 	} /* while(*fmt) */
3370 
3371 out:
3372 	if (size > 0) {
3373 		if (str < end)
3374 			*str = '\0';
3375 		else
3376 			end[-1] = '\0';
3377 	}
3378 
3379 #undef get_arg
3380 
3381 	/* the trailing null byte doesn't count towards the total */
3382 	return str - buf;
3383 }
3384 EXPORT_SYMBOL_GPL(bstr_printf);
3385 
3386 /**
3387  * bprintf - Parse a format string and place args' binary value in a buffer
3388  * @bin_buf: The buffer to place args' binary value
3389  * @size: The size of the buffer(by words(32bits), not characters)
3390  * @fmt: The format string to use
3391  * @...: Arguments for the format string
3392  *
3393  * The function returns the number of words(u32) written
3394  * into @bin_buf.
3395  */
bprintf(u32 * bin_buf,size_t size,const char * fmt,...)3396 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3397 {
3398 	va_list args;
3399 	int ret;
3400 
3401 	va_start(args, fmt);
3402 	ret = vbin_printf(bin_buf, size, fmt, args);
3403 	va_end(args);
3404 
3405 	return ret;
3406 }
3407 EXPORT_SYMBOL_GPL(bprintf);
3408 
3409 #endif /* CONFIG_BINARY_PRINTF */
3410 
3411 /**
3412  * vsscanf - Unformat a buffer into a list of arguments
3413  * @buf:	input buffer
3414  * @fmt:	format of buffer
3415  * @args:	arguments
3416  */
vsscanf(const char * buf,const char * fmt,va_list args)3417 int vsscanf(const char *buf, const char *fmt, va_list args)
3418 {
3419 	const char *str = buf;
3420 	char *next;
3421 	char digit;
3422 	int num = 0;
3423 	u8 qualifier;
3424 	unsigned int base;
3425 	union {
3426 		long long s;
3427 		unsigned long long u;
3428 	} val;
3429 	s16 field_width;
3430 	bool is_sign;
3431 
3432 	while (*fmt) {
3433 		/* skip any white space in format */
3434 		/* white space in format matches any amount of
3435 		 * white space, including none, in the input.
3436 		 */
3437 		if (isspace(*fmt)) {
3438 			fmt = skip_spaces(++fmt);
3439 			str = skip_spaces(str);
3440 		}
3441 
3442 		/* anything that is not a conversion must match exactly */
3443 		if (*fmt != '%' && *fmt) {
3444 			if (*fmt++ != *str++)
3445 				break;
3446 			continue;
3447 		}
3448 
3449 		if (!*fmt)
3450 			break;
3451 		++fmt;
3452 
3453 		/* skip this conversion.
3454 		 * advance both strings to next white space
3455 		 */
3456 		if (*fmt == '*') {
3457 			if (!*str)
3458 				break;
3459 			while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3460 				/* '%*[' not yet supported, invalid format */
3461 				if (*fmt == '[')
3462 					return num;
3463 				fmt++;
3464 			}
3465 			while (!isspace(*str) && *str)
3466 				str++;
3467 			continue;
3468 		}
3469 
3470 		/* get field width */
3471 		field_width = -1;
3472 		if (isdigit(*fmt)) {
3473 			field_width = skip_atoi(&fmt);
3474 			if (field_width <= 0)
3475 				break;
3476 		}
3477 
3478 		/* get conversion qualifier */
3479 		qualifier = -1;
3480 		if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3481 		    *fmt == 'z') {
3482 			qualifier = *fmt++;
3483 			if (unlikely(qualifier == *fmt)) {
3484 				if (qualifier == 'h') {
3485 					qualifier = 'H';
3486 					fmt++;
3487 				} else if (qualifier == 'l') {
3488 					qualifier = 'L';
3489 					fmt++;
3490 				}
3491 			}
3492 		}
3493 
3494 		if (!*fmt)
3495 			break;
3496 
3497 		if (*fmt == 'n') {
3498 			/* return number of characters read so far */
3499 			*va_arg(args, int *) = str - buf;
3500 			++fmt;
3501 			continue;
3502 		}
3503 
3504 		if (!*str)
3505 			break;
3506 
3507 		base = 10;
3508 		is_sign = false;
3509 
3510 		switch (*fmt++) {
3511 		case 'c':
3512 		{
3513 			char *s = (char *)va_arg(args, char*);
3514 			if (field_width == -1)
3515 				field_width = 1;
3516 			do {
3517 				*s++ = *str++;
3518 			} while (--field_width > 0 && *str);
3519 			num++;
3520 		}
3521 		continue;
3522 		case 's':
3523 		{
3524 			char *s = (char *)va_arg(args, char *);
3525 			if (field_width == -1)
3526 				field_width = SHRT_MAX;
3527 			/* first, skip leading white space in buffer */
3528 			str = skip_spaces(str);
3529 
3530 			/* now copy until next white space */
3531 			while (*str && !isspace(*str) && field_width--)
3532 				*s++ = *str++;
3533 			*s = '\0';
3534 			num++;
3535 		}
3536 		continue;
3537 		/*
3538 		 * Warning: This implementation of the '[' conversion specifier
3539 		 * deviates from its glibc counterpart in the following ways:
3540 		 * (1) It does NOT support ranges i.e. '-' is NOT a special
3541 		 *     character
3542 		 * (2) It cannot match the closing bracket ']' itself
3543 		 * (3) A field width is required
3544 		 * (4) '%*[' (discard matching input) is currently not supported
3545 		 *
3546 		 * Example usage:
3547 		 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3548 		 *		buf1, buf2, buf3);
3549 		 * if (ret < 3)
3550 		 *    // etc..
3551 		 */
3552 		case '[':
3553 		{
3554 			char *s = (char *)va_arg(args, char *);
3555 			DECLARE_BITMAP(set, 256) = {0};
3556 			unsigned int len = 0;
3557 			bool negate = (*fmt == '^');
3558 
3559 			/* field width is required */
3560 			if (field_width == -1)
3561 				return num;
3562 
3563 			if (negate)
3564 				++fmt;
3565 
3566 			for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3567 				__set_bit((u8)*fmt, set);
3568 
3569 			/* no ']' or no character set found */
3570 			if (!*fmt || !len)
3571 				return num;
3572 			++fmt;
3573 
3574 			if (negate) {
3575 				bitmap_complement(set, set, 256);
3576 				/* exclude null '\0' byte */
3577 				__clear_bit(0, set);
3578 			}
3579 
3580 			/* match must be non-empty */
3581 			if (!test_bit((u8)*str, set))
3582 				return num;
3583 
3584 			while (test_bit((u8)*str, set) && field_width--)
3585 				*s++ = *str++;
3586 			*s = '\0';
3587 			++num;
3588 		}
3589 		continue;
3590 		case 'o':
3591 			base = 8;
3592 			break;
3593 		case 'x':
3594 		case 'X':
3595 			base = 16;
3596 			break;
3597 		case 'i':
3598 			base = 0;
3599 			fallthrough;
3600 		case 'd':
3601 			is_sign = true;
3602 			fallthrough;
3603 		case 'u':
3604 			break;
3605 		case '%':
3606 			/* looking for '%' in str */
3607 			if (*str++ != '%')
3608 				return num;
3609 			continue;
3610 		default:
3611 			/* invalid format; stop here */
3612 			return num;
3613 		}
3614 
3615 		/* have some sort of integer conversion.
3616 		 * first, skip white space in buffer.
3617 		 */
3618 		str = skip_spaces(str);
3619 
3620 		digit = *str;
3621 		if (is_sign && digit == '-') {
3622 			if (field_width == 1)
3623 				break;
3624 
3625 			digit = *(str + 1);
3626 		}
3627 
3628 		if (!digit
3629 		    || (base == 16 && !isxdigit(digit))
3630 		    || (base == 10 && !isdigit(digit))
3631 		    || (base == 8 && !isodigit(digit))
3632 		    || (base == 0 && !isdigit(digit)))
3633 			break;
3634 
3635 		if (is_sign)
3636 			val.s = simple_strntoll(str, &next, base,
3637 						field_width >= 0 ? field_width : INT_MAX);
3638 		else
3639 			val.u = simple_strntoull(str, &next, base,
3640 						 field_width >= 0 ? field_width : INT_MAX);
3641 
3642 		switch (qualifier) {
3643 		case 'H':	/* that's 'hh' in format */
3644 			if (is_sign)
3645 				*va_arg(args, signed char *) = val.s;
3646 			else
3647 				*va_arg(args, unsigned char *) = val.u;
3648 			break;
3649 		case 'h':
3650 			if (is_sign)
3651 				*va_arg(args, short *) = val.s;
3652 			else
3653 				*va_arg(args, unsigned short *) = val.u;
3654 			break;
3655 		case 'l':
3656 			if (is_sign)
3657 				*va_arg(args, long *) = val.s;
3658 			else
3659 				*va_arg(args, unsigned long *) = val.u;
3660 			break;
3661 		case 'L':
3662 			if (is_sign)
3663 				*va_arg(args, long long *) = val.s;
3664 			else
3665 				*va_arg(args, unsigned long long *) = val.u;
3666 			break;
3667 		case 'z':
3668 			*va_arg(args, size_t *) = val.u;
3669 			break;
3670 		default:
3671 			if (is_sign)
3672 				*va_arg(args, int *) = val.s;
3673 			else
3674 				*va_arg(args, unsigned int *) = val.u;
3675 			break;
3676 		}
3677 		num++;
3678 
3679 		if (!next)
3680 			break;
3681 		str = next;
3682 	}
3683 
3684 	return num;
3685 }
3686 EXPORT_SYMBOL(vsscanf);
3687 
3688 /**
3689  * sscanf - Unformat a buffer into a list of arguments
3690  * @buf:	input buffer
3691  * @fmt:	formatting of buffer
3692  * @...:	resulting arguments
3693  */
sscanf(const char * buf,const char * fmt,...)3694 int sscanf(const char *buf, const char *fmt, ...)
3695 {
3696 	va_list args;
3697 	int i;
3698 
3699 	va_start(args, fmt);
3700 	i = vsscanf(buf, fmt, args);
3701 	va_end(args);
3702 
3703 	return i;
3704 }
3705 EXPORT_SYMBOL(sscanf);
3706