1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/lib/vsprintf.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
11 */
12
13 /*
14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17 * - scnprintf and vscnprintf
18 */
19
20 #include <stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/time.h>
38 #include <linux/uuid.h>
39 #include <linux/of.h>
40 #include <net/addrconf.h>
41 #include <linux/siphash.h>
42 #include <linux/compiler.h>
43 #include <linux/property.h>
44 #ifdef CONFIG_BLOCK
45 #include <linux/blkdev.h>
46 #endif
47
48 #include "../mm/internal.h" /* For the trace_print_flags arrays */
49
50 #include <asm/page.h> /* for PAGE_SIZE */
51 #include <asm/byteorder.h> /* cpu_to_le16 */
52
53 #include <linux/string_helpers.h>
54 #include "kstrtox.h"
55
simple_strntoull(const char * startp,size_t max_chars,char ** endp,unsigned int base)56 static unsigned long long simple_strntoull(const char *startp, size_t max_chars,
57 char **endp, unsigned int base)
58 {
59 const char *cp;
60 unsigned long long result = 0ULL;
61 size_t prefix_chars;
62 unsigned int rv;
63
64 cp = _parse_integer_fixup_radix(startp, &base);
65 prefix_chars = cp - startp;
66 if (prefix_chars < max_chars) {
67 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
68 /* FIXME */
69 cp += (rv & ~KSTRTOX_OVERFLOW);
70 } else {
71 /* Field too short for prefix + digit, skip over without converting */
72 cp = startp + max_chars;
73 }
74
75 if (endp)
76 *endp = (char *)cp;
77
78 return result;
79 }
80
81 /**
82 * simple_strtoull - convert a string to an unsigned long long
83 * @cp: The start of the string
84 * @endp: A pointer to the end of the parsed string will be placed here
85 * @base: The number base to use
86 *
87 * This function has caveats. Please use kstrtoull instead.
88 */
simple_strtoull(const char * cp,char ** endp,unsigned int base)89 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
90 {
91 return simple_strntoull(cp, INT_MAX, endp, base);
92 }
93 EXPORT_SYMBOL(simple_strtoull);
94
95 /**
96 * simple_strtoul - convert a string to an unsigned long
97 * @cp: The start of the string
98 * @endp: A pointer to the end of the parsed string will be placed here
99 * @base: The number base to use
100 *
101 * This function has caveats. Please use kstrtoul instead.
102 */
simple_strtoul(const char * cp,char ** endp,unsigned int base)103 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
104 {
105 return simple_strtoull(cp, endp, base);
106 }
107 EXPORT_SYMBOL(simple_strtoul);
108
109 /**
110 * simple_strtol - convert a string to a signed long
111 * @cp: The start of the string
112 * @endp: A pointer to the end of the parsed string will be placed here
113 * @base: The number base to use
114 *
115 * This function has caveats. Please use kstrtol instead.
116 */
simple_strtol(const char * cp,char ** endp,unsigned int base)117 long simple_strtol(const char *cp, char **endp, unsigned int base)
118 {
119 if (*cp == '-')
120 return -simple_strtoul(cp + 1, endp, base);
121
122 return simple_strtoul(cp, endp, base);
123 }
124 EXPORT_SYMBOL(simple_strtol);
125
simple_strntoll(const char * cp,size_t max_chars,char ** endp,unsigned int base)126 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
127 unsigned int base)
128 {
129 /*
130 * simple_strntoull() safely handles receiving max_chars==0 in the
131 * case cp[0] == '-' && max_chars == 1.
132 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
133 * and the content of *cp is irrelevant.
134 */
135 if (*cp == '-' && max_chars > 0)
136 return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
137
138 return simple_strntoull(cp, max_chars, endp, base);
139 }
140
141 /**
142 * simple_strtoll - convert a string to a signed long long
143 * @cp: The start of the string
144 * @endp: A pointer to the end of the parsed string will be placed here
145 * @base: The number base to use
146 *
147 * This function has caveats. Please use kstrtoll instead.
148 */
simple_strtoll(const char * cp,char ** endp,unsigned int base)149 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
150 {
151 return simple_strntoll(cp, INT_MAX, endp, base);
152 }
153 EXPORT_SYMBOL(simple_strtoll);
154
155 static noinline_for_stack
skip_atoi(const char ** s)156 int skip_atoi(const char **s)
157 {
158 int i = 0;
159
160 do {
161 i = i*10 + *((*s)++) - '0';
162 } while (isdigit(**s));
163
164 return i;
165 }
166
167 /*
168 * Decimal conversion is by far the most typical, and is used for
169 * /proc and /sys data. This directly impacts e.g. top performance
170 * with many processes running. We optimize it for speed by emitting
171 * two characters at a time, using a 200 byte lookup table. This
172 * roughly halves the number of multiplications compared to computing
173 * the digits one at a time. Implementation strongly inspired by the
174 * previous version, which in turn used ideas described at
175 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
176 * from the author, Douglas W. Jones).
177 *
178 * It turns out there is precisely one 26 bit fixed-point
179 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
180 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
181 * range happens to be somewhat larger (x <= 1073741898), but that's
182 * irrelevant for our purpose.
183 *
184 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
185 * need a 32x32->64 bit multiply, so we simply use the same constant.
186 *
187 * For dividing a number in the range [100, 10^4-1] by 100, there are
188 * several options. The simplest is (x * 0x147b) >> 19, which is valid
189 * for all x <= 43698.
190 */
191
192 static const u16 decpair[100] = {
193 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
194 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
195 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
196 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
197 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
198 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
199 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
200 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
201 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
202 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
203 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
204 #undef _
205 };
206
207 /*
208 * This will print a single '0' even if r == 0, since we would
209 * immediately jump to out_r where two 0s would be written but only
210 * one of them accounted for in buf. This is needed by ip4_string
211 * below. All other callers pass a non-zero value of r.
212 */
213 static noinline_for_stack
put_dec_trunc8(char * buf,unsigned r)214 char *put_dec_trunc8(char *buf, unsigned r)
215 {
216 unsigned q;
217
218 /* 1 <= r < 10^8 */
219 if (r < 100)
220 goto out_r;
221
222 /* 100 <= r < 10^8 */
223 q = (r * (u64)0x28f5c29) >> 32;
224 *((u16 *)buf) = decpair[r - 100*q];
225 buf += 2;
226
227 /* 1 <= q < 10^6 */
228 if (q < 100)
229 goto out_q;
230
231 /* 100 <= q < 10^6 */
232 r = (q * (u64)0x28f5c29) >> 32;
233 *((u16 *)buf) = decpair[q - 100*r];
234 buf += 2;
235
236 /* 1 <= r < 10^4 */
237 if (r < 100)
238 goto out_r;
239
240 /* 100 <= r < 10^4 */
241 q = (r * 0x147b) >> 19;
242 *((u16 *)buf) = decpair[r - 100*q];
243 buf += 2;
244 out_q:
245 /* 1 <= q < 100 */
246 r = q;
247 out_r:
248 /* 1 <= r < 100 */
249 *((u16 *)buf) = decpair[r];
250 buf += r < 10 ? 1 : 2;
251 return buf;
252 }
253
254 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
255 static noinline_for_stack
put_dec_full8(char * buf,unsigned r)256 char *put_dec_full8(char *buf, unsigned r)
257 {
258 unsigned q;
259
260 /* 0 <= r < 10^8 */
261 q = (r * (u64)0x28f5c29) >> 32;
262 *((u16 *)buf) = decpair[r - 100*q];
263 buf += 2;
264
265 /* 0 <= q < 10^6 */
266 r = (q * (u64)0x28f5c29) >> 32;
267 *((u16 *)buf) = decpair[q - 100*r];
268 buf += 2;
269
270 /* 0 <= r < 10^4 */
271 q = (r * 0x147b) >> 19;
272 *((u16 *)buf) = decpair[r - 100*q];
273 buf += 2;
274
275 /* 0 <= q < 100 */
276 *((u16 *)buf) = decpair[q];
277 buf += 2;
278 return buf;
279 }
280
281 static noinline_for_stack
put_dec(char * buf,unsigned long long n)282 char *put_dec(char *buf, unsigned long long n)
283 {
284 if (n >= 100*1000*1000)
285 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
286 /* 1 <= n <= 1.6e11 */
287 if (n >= 100*1000*1000)
288 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
289 /* 1 <= n < 1e8 */
290 return put_dec_trunc8(buf, n);
291 }
292
293 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
294
295 static void
put_dec_full4(char * buf,unsigned r)296 put_dec_full4(char *buf, unsigned r)
297 {
298 unsigned q;
299
300 /* 0 <= r < 10^4 */
301 q = (r * 0x147b) >> 19;
302 *((u16 *)buf) = decpair[r - 100*q];
303 buf += 2;
304 /* 0 <= q < 100 */
305 *((u16 *)buf) = decpair[q];
306 }
307
308 /*
309 * Call put_dec_full4 on x % 10000, return x / 10000.
310 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
311 * holds for all x < 1,128,869,999. The largest value this
312 * helper will ever be asked to convert is 1,125,520,955.
313 * (second call in the put_dec code, assuming n is all-ones).
314 */
315 static noinline_for_stack
put_dec_helper4(char * buf,unsigned x)316 unsigned put_dec_helper4(char *buf, unsigned x)
317 {
318 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
319
320 put_dec_full4(buf, x - q * 10000);
321 return q;
322 }
323
324 /* Based on code by Douglas W. Jones found at
325 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
326 * (with permission from the author).
327 * Performs no 64-bit division and hence should be fast on 32-bit machines.
328 */
329 static
put_dec(char * buf,unsigned long long n)330 char *put_dec(char *buf, unsigned long long n)
331 {
332 uint32_t d3, d2, d1, q, h;
333
334 if (n < 100*1000*1000)
335 return put_dec_trunc8(buf, n);
336
337 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
338 h = (n >> 32);
339 d2 = (h ) & 0xffff;
340 d3 = (h >> 16); /* implicit "& 0xffff" */
341
342 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
343 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
344 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
345 q = put_dec_helper4(buf, q);
346
347 q += 7671 * d3 + 9496 * d2 + 6 * d1;
348 q = put_dec_helper4(buf+4, q);
349
350 q += 4749 * d3 + 42 * d2;
351 q = put_dec_helper4(buf+8, q);
352
353 q += 281 * d3;
354 buf += 12;
355 if (q)
356 buf = put_dec_trunc8(buf, q);
357 else while (buf[-1] == '0')
358 --buf;
359
360 return buf;
361 }
362
363 #endif
364
365 /*
366 * Convert passed number to decimal string.
367 * Returns the length of string. On buffer overflow, returns 0.
368 *
369 * If speed is not important, use snprintf(). It's easy to read the code.
370 */
num_to_str(char * buf,int size,unsigned long long num,unsigned int width)371 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
372 {
373 /* put_dec requires 2-byte alignment of the buffer. */
374 char tmp[sizeof(num) * 3] __aligned(2);
375 int idx, len;
376
377 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
378 if (num <= 9) {
379 tmp[0] = '0' + num;
380 len = 1;
381 } else {
382 len = put_dec(tmp, num) - tmp;
383 }
384
385 if (len > size || width > size)
386 return 0;
387
388 if (width > len) {
389 width = width - len;
390 for (idx = 0; idx < width; idx++)
391 buf[idx] = ' ';
392 } else {
393 width = 0;
394 }
395
396 for (idx = 0; idx < len; ++idx)
397 buf[idx + width] = tmp[len - idx - 1];
398
399 return len + width;
400 }
401
402 #define SIGN 1 /* unsigned/signed, must be 1 */
403 #define LEFT 2 /* left justified */
404 #define PLUS 4 /* show plus */
405 #define SPACE 8 /* space if plus */
406 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
407 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
408 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
409
410 static_assert(ZEROPAD == ('0' - ' '));
411 static_assert(SMALL == ' ');
412
413 enum format_type {
414 FORMAT_TYPE_NONE, /* Just a string part */
415 FORMAT_TYPE_WIDTH,
416 FORMAT_TYPE_PRECISION,
417 FORMAT_TYPE_CHAR,
418 FORMAT_TYPE_STR,
419 FORMAT_TYPE_PTR,
420 FORMAT_TYPE_PERCENT_CHAR,
421 FORMAT_TYPE_INVALID,
422 FORMAT_TYPE_LONG_LONG,
423 FORMAT_TYPE_ULONG,
424 FORMAT_TYPE_LONG,
425 FORMAT_TYPE_UBYTE,
426 FORMAT_TYPE_BYTE,
427 FORMAT_TYPE_USHORT,
428 FORMAT_TYPE_SHORT,
429 FORMAT_TYPE_UINT,
430 FORMAT_TYPE_INT,
431 FORMAT_TYPE_SIZE_T,
432 FORMAT_TYPE_PTRDIFF
433 };
434
435 struct printf_spec {
436 unsigned int type:8; /* format_type enum */
437 signed int field_width:24; /* width of output field */
438 unsigned int flags:8; /* flags to number() */
439 unsigned int base:8; /* number base, 8, 10 or 16 only */
440 signed int precision:16; /* # of digits/chars */
441 } __packed;
442 static_assert(sizeof(struct printf_spec) == 8);
443
444 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
445 #define PRECISION_MAX ((1 << 15) - 1)
446
447 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)448 char *number(char *buf, char *end, unsigned long long num,
449 struct printf_spec spec)
450 {
451 /* put_dec requires 2-byte alignment of the buffer. */
452 char tmp[3 * sizeof(num)] __aligned(2);
453 char sign;
454 char locase;
455 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
456 int i;
457 bool is_zero = num == 0LL;
458 int field_width = spec.field_width;
459 int precision = spec.precision;
460
461 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
462 * produces same digits or (maybe lowercased) letters */
463 locase = (spec.flags & SMALL);
464 if (spec.flags & LEFT)
465 spec.flags &= ~ZEROPAD;
466 sign = 0;
467 if (spec.flags & SIGN) {
468 if ((signed long long)num < 0) {
469 sign = '-';
470 num = -(signed long long)num;
471 field_width--;
472 } else if (spec.flags & PLUS) {
473 sign = '+';
474 field_width--;
475 } else if (spec.flags & SPACE) {
476 sign = ' ';
477 field_width--;
478 }
479 }
480 if (need_pfx) {
481 if (spec.base == 16)
482 field_width -= 2;
483 else if (!is_zero)
484 field_width--;
485 }
486
487 /* generate full string in tmp[], in reverse order */
488 i = 0;
489 if (num < spec.base)
490 tmp[i++] = hex_asc_upper[num] | locase;
491 else if (spec.base != 10) { /* 8 or 16 */
492 int mask = spec.base - 1;
493 int shift = 3;
494
495 if (spec.base == 16)
496 shift = 4;
497 do {
498 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
499 num >>= shift;
500 } while (num);
501 } else { /* base 10 */
502 i = put_dec(tmp, num) - tmp;
503 }
504
505 /* printing 100 using %2d gives "100", not "00" */
506 if (i > precision)
507 precision = i;
508 /* leading space padding */
509 field_width -= precision;
510 if (!(spec.flags & (ZEROPAD | LEFT))) {
511 while (--field_width >= 0) {
512 if (buf < end)
513 *buf = ' ';
514 ++buf;
515 }
516 }
517 /* sign */
518 if (sign) {
519 if (buf < end)
520 *buf = sign;
521 ++buf;
522 }
523 /* "0x" / "0" prefix */
524 if (need_pfx) {
525 if (spec.base == 16 || !is_zero) {
526 if (buf < end)
527 *buf = '0';
528 ++buf;
529 }
530 if (spec.base == 16) {
531 if (buf < end)
532 *buf = ('X' | locase);
533 ++buf;
534 }
535 }
536 /* zero or space padding */
537 if (!(spec.flags & LEFT)) {
538 char c = ' ' + (spec.flags & ZEROPAD);
539
540 while (--field_width >= 0) {
541 if (buf < end)
542 *buf = c;
543 ++buf;
544 }
545 }
546 /* hmm even more zero padding? */
547 while (i <= --precision) {
548 if (buf < end)
549 *buf = '0';
550 ++buf;
551 }
552 /* actual digits of result */
553 while (--i >= 0) {
554 if (buf < end)
555 *buf = tmp[i];
556 ++buf;
557 }
558 /* trailing space padding */
559 while (--field_width >= 0) {
560 if (buf < end)
561 *buf = ' ';
562 ++buf;
563 }
564
565 return buf;
566 }
567
568 static noinline_for_stack
special_hex_number(char * buf,char * end,unsigned long long num,int size)569 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
570 {
571 struct printf_spec spec;
572
573 spec.type = FORMAT_TYPE_PTR;
574 spec.field_width = 2 + 2 * size; /* 0x + hex */
575 spec.flags = SPECIAL | SMALL | ZEROPAD;
576 spec.base = 16;
577 spec.precision = -1;
578
579 return number(buf, end, num, spec);
580 }
581
move_right(char * buf,char * end,unsigned len,unsigned spaces)582 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
583 {
584 size_t size;
585 if (buf >= end) /* nowhere to put anything */
586 return;
587 size = end - buf;
588 if (size <= spaces) {
589 memset(buf, ' ', size);
590 return;
591 }
592 if (len) {
593 if (len > size - spaces)
594 len = size - spaces;
595 memmove(buf + spaces, buf, len);
596 }
597 memset(buf, ' ', spaces);
598 }
599
600 /*
601 * Handle field width padding for a string.
602 * @buf: current buffer position
603 * @n: length of string
604 * @end: end of output buffer
605 * @spec: for field width and flags
606 * Returns: new buffer position after padding.
607 */
608 static noinline_for_stack
widen_string(char * buf,int n,char * end,struct printf_spec spec)609 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
610 {
611 unsigned spaces;
612
613 if (likely(n >= spec.field_width))
614 return buf;
615 /* we want to pad the sucker */
616 spaces = spec.field_width - n;
617 if (!(spec.flags & LEFT)) {
618 move_right(buf - n, end, n, spaces);
619 return buf + spaces;
620 }
621 while (spaces--) {
622 if (buf < end)
623 *buf = ' ';
624 ++buf;
625 }
626 return buf;
627 }
628
629 /* Handle string from a well known address. */
string_nocheck(char * buf,char * end,const char * s,struct printf_spec spec)630 static char *string_nocheck(char *buf, char *end, const char *s,
631 struct printf_spec spec)
632 {
633 int len = 0;
634 int lim = spec.precision;
635
636 while (lim--) {
637 char c = *s++;
638 if (!c)
639 break;
640 if (buf < end)
641 *buf = c;
642 ++buf;
643 ++len;
644 }
645 return widen_string(buf, len, end, spec);
646 }
647
err_ptr(char * buf,char * end,void * ptr,struct printf_spec spec)648 static char *err_ptr(char *buf, char *end, void *ptr,
649 struct printf_spec spec)
650 {
651 int err = PTR_ERR(ptr);
652 const char *sym = errname(err);
653
654 if (sym)
655 return string_nocheck(buf, end, sym, spec);
656
657 /*
658 * Somebody passed ERR_PTR(-1234) or some other non-existing
659 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
660 * printing it as its decimal representation.
661 */
662 spec.flags |= SIGN;
663 spec.base = 10;
664 return number(buf, end, err, spec);
665 }
666
667 /* Be careful: error messages must fit into the given buffer. */
error_string(char * buf,char * end,const char * s,struct printf_spec spec)668 static char *error_string(char *buf, char *end, const char *s,
669 struct printf_spec spec)
670 {
671 /*
672 * Hard limit to avoid a completely insane messages. It actually
673 * works pretty well because most error messages are in
674 * the many pointer format modifiers.
675 */
676 if (spec.precision == -1)
677 spec.precision = 2 * sizeof(void *);
678
679 return string_nocheck(buf, end, s, spec);
680 }
681
682 /*
683 * Do not call any complex external code here. Nested printk()/vsprintf()
684 * might cause infinite loops. Failures might break printk() and would
685 * be hard to debug.
686 */
check_pointer_msg(const void * ptr)687 static const char *check_pointer_msg(const void *ptr)
688 {
689 if (!ptr)
690 return "(null)";
691
692 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
693 return "(efault)";
694
695 return NULL;
696 }
697
check_pointer(char ** buf,char * end,const void * ptr,struct printf_spec spec)698 static int check_pointer(char **buf, char *end, const void *ptr,
699 struct printf_spec spec)
700 {
701 const char *err_msg;
702
703 err_msg = check_pointer_msg(ptr);
704 if (err_msg) {
705 *buf = error_string(*buf, end, err_msg, spec);
706 return -EFAULT;
707 }
708
709 return 0;
710 }
711
712 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)713 char *string(char *buf, char *end, const char *s,
714 struct printf_spec spec)
715 {
716 if (check_pointer(&buf, end, s, spec))
717 return buf;
718
719 return string_nocheck(buf, end, s, spec);
720 }
721
pointer_string(char * buf,char * end,const void * ptr,struct printf_spec spec)722 static char *pointer_string(char *buf, char *end,
723 const void *ptr,
724 struct printf_spec spec)
725 {
726 spec.base = 16;
727 spec.flags |= SMALL;
728 if (spec.field_width == -1) {
729 spec.field_width = 2 * sizeof(ptr);
730 spec.flags |= ZEROPAD;
731 }
732
733 return number(buf, end, (unsigned long int)ptr, spec);
734 }
735
736 /* Make pointers available for printing early in the boot sequence. */
737 static int debug_boot_weak_hash __ro_after_init;
738
debug_boot_weak_hash_enable(char * str)739 static int __init debug_boot_weak_hash_enable(char *str)
740 {
741 debug_boot_weak_hash = 1;
742 pr_info("debug_boot_weak_hash enabled\n");
743 return 0;
744 }
745 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
746
747 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
748 static siphash_key_t ptr_key __read_mostly;
749
enable_ptr_key_workfn(struct work_struct * work)750 static void enable_ptr_key_workfn(struct work_struct *work)
751 {
752 get_random_bytes(&ptr_key, sizeof(ptr_key));
753 /* Needs to run from preemptible context */
754 static_branch_disable(¬_filled_random_ptr_key);
755 }
756
757 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
758
fill_random_ptr_key(struct random_ready_callback * unused)759 static void fill_random_ptr_key(struct random_ready_callback *unused)
760 {
761 /* This may be in an interrupt handler. */
762 queue_work(system_unbound_wq, &enable_ptr_key_work);
763 }
764
765 static struct random_ready_callback random_ready = {
766 .func = fill_random_ptr_key
767 };
768
initialize_ptr_random(void)769 static int __init initialize_ptr_random(void)
770 {
771 int key_size = sizeof(ptr_key);
772 int ret;
773
774 /* Use hw RNG if available. */
775 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
776 static_branch_disable(¬_filled_random_ptr_key);
777 return 0;
778 }
779
780 ret = add_random_ready_callback(&random_ready);
781 if (!ret) {
782 return 0;
783 } else if (ret == -EALREADY) {
784 /* This is in preemptible context */
785 enable_ptr_key_workfn(&enable_ptr_key_work);
786 return 0;
787 }
788
789 return ret;
790 }
791 early_initcall(initialize_ptr_random);
792
793 /* Maps a pointer to a 32 bit unique identifier. */
__ptr_to_hashval(const void * ptr,unsigned long * hashval_out)794 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
795 {
796 unsigned long hashval;
797
798 if (static_branch_unlikely(¬_filled_random_ptr_key))
799 return -EAGAIN;
800
801 #ifdef CONFIG_64BIT
802 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
803 /*
804 * Mask off the first 32 bits, this makes explicit that we have
805 * modified the address (and 32 bits is plenty for a unique ID).
806 */
807 hashval = hashval & 0xffffffff;
808 #else
809 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
810 #endif
811 *hashval_out = hashval;
812 return 0;
813 }
814
ptr_to_hashval(const void * ptr,unsigned long * hashval_out)815 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
816 {
817 return __ptr_to_hashval(ptr, hashval_out);
818 }
819
ptr_to_id(char * buf,char * end,const void * ptr,struct printf_spec spec)820 static char *ptr_to_id(char *buf, char *end, const void *ptr,
821 struct printf_spec spec)
822 {
823 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
824 unsigned long hashval;
825 int ret;
826
827 /*
828 * Print the real pointer value for NULL and error pointers,
829 * as they are not actual addresses.
830 */
831 if (IS_ERR_OR_NULL(ptr))
832 return pointer_string(buf, end, ptr, spec);
833
834 /* When debugging early boot use non-cryptographically secure hash. */
835 if (unlikely(debug_boot_weak_hash)) {
836 hashval = hash_long((unsigned long)ptr, 32);
837 return pointer_string(buf, end, (const void *)hashval, spec);
838 }
839
840 ret = __ptr_to_hashval(ptr, &hashval);
841 if (ret) {
842 spec.field_width = 2 * sizeof(ptr);
843 /* string length must be less than default_width */
844 return error_string(buf, end, str, spec);
845 }
846
847 return pointer_string(buf, end, (const void *)hashval, 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 ptr_to_id(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_irq() || 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->bd_partno) {
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->bd_partno, 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')
996 sprint_backtrace(sym, value);
997 else if (*fmt != 's')
998 sprint_symbol(sym, value);
999 else
1000 sprint_symbol_no_offset(sym, value);
1001
1002 return string_nocheck(buf, end, sym, spec);
1003 #else
1004 return special_hex_number(buf, end, value, sizeof(void *));
1005 #endif
1006 }
1007
1008 static const struct printf_spec default_str_spec = {
1009 .field_width = -1,
1010 .precision = -1,
1011 };
1012
1013 static const struct printf_spec default_flag_spec = {
1014 .base = 16,
1015 .precision = -1,
1016 .flags = SPECIAL | SMALL,
1017 };
1018
1019 static const struct printf_spec default_dec_spec = {
1020 .base = 10,
1021 .precision = -1,
1022 };
1023
1024 static const struct printf_spec default_dec02_spec = {
1025 .base = 10,
1026 .field_width = 2,
1027 .precision = -1,
1028 .flags = ZEROPAD,
1029 };
1030
1031 static const struct printf_spec default_dec04_spec = {
1032 .base = 10,
1033 .field_width = 4,
1034 .precision = -1,
1035 .flags = ZEROPAD,
1036 };
1037
1038 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)1039 char *resource_string(char *buf, char *end, struct resource *res,
1040 struct printf_spec spec, const char *fmt)
1041 {
1042 #ifndef IO_RSRC_PRINTK_SIZE
1043 #define IO_RSRC_PRINTK_SIZE 6
1044 #endif
1045
1046 #ifndef MEM_RSRC_PRINTK_SIZE
1047 #define MEM_RSRC_PRINTK_SIZE 10
1048 #endif
1049 static const struct printf_spec io_spec = {
1050 .base = 16,
1051 .field_width = IO_RSRC_PRINTK_SIZE,
1052 .precision = -1,
1053 .flags = SPECIAL | SMALL | ZEROPAD,
1054 };
1055 static const struct printf_spec mem_spec = {
1056 .base = 16,
1057 .field_width = MEM_RSRC_PRINTK_SIZE,
1058 .precision = -1,
1059 .flags = SPECIAL | SMALL | ZEROPAD,
1060 };
1061 static const struct printf_spec bus_spec = {
1062 .base = 16,
1063 .field_width = 2,
1064 .precision = -1,
1065 .flags = SMALL | ZEROPAD,
1066 };
1067 static const struct printf_spec str_spec = {
1068 .field_width = -1,
1069 .precision = 10,
1070 .flags = LEFT,
1071 };
1072
1073 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1074 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1075 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1076 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1077 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1078 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1079 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1080 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1081
1082 char *p = sym, *pend = sym + sizeof(sym);
1083 int decode = (fmt[0] == 'R') ? 1 : 0;
1084 const struct printf_spec *specp;
1085
1086 if (check_pointer(&buf, end, res, spec))
1087 return buf;
1088
1089 *p++ = '[';
1090 if (res->flags & IORESOURCE_IO) {
1091 p = string_nocheck(p, pend, "io ", str_spec);
1092 specp = &io_spec;
1093 } else if (res->flags & IORESOURCE_MEM) {
1094 p = string_nocheck(p, pend, "mem ", str_spec);
1095 specp = &mem_spec;
1096 } else if (res->flags & IORESOURCE_IRQ) {
1097 p = string_nocheck(p, pend, "irq ", str_spec);
1098 specp = &default_dec_spec;
1099 } else if (res->flags & IORESOURCE_DMA) {
1100 p = string_nocheck(p, pend, "dma ", str_spec);
1101 specp = &default_dec_spec;
1102 } else if (res->flags & IORESOURCE_BUS) {
1103 p = string_nocheck(p, pend, "bus ", str_spec);
1104 specp = &bus_spec;
1105 } else {
1106 p = string_nocheck(p, pend, "??? ", str_spec);
1107 specp = &mem_spec;
1108 decode = 0;
1109 }
1110 if (decode && res->flags & IORESOURCE_UNSET) {
1111 p = string_nocheck(p, pend, "size ", str_spec);
1112 p = number(p, pend, resource_size(res), *specp);
1113 } else {
1114 p = number(p, pend, res->start, *specp);
1115 if (res->start != res->end) {
1116 *p++ = '-';
1117 p = number(p, pend, res->end, *specp);
1118 }
1119 }
1120 if (decode) {
1121 if (res->flags & IORESOURCE_MEM_64)
1122 p = string_nocheck(p, pend, " 64bit", str_spec);
1123 if (res->flags & IORESOURCE_PREFETCH)
1124 p = string_nocheck(p, pend, " pref", str_spec);
1125 if (res->flags & IORESOURCE_WINDOW)
1126 p = string_nocheck(p, pend, " window", str_spec);
1127 if (res->flags & IORESOURCE_DISABLED)
1128 p = string_nocheck(p, pend, " disabled", str_spec);
1129 } else {
1130 p = string_nocheck(p, pend, " flags ", str_spec);
1131 p = number(p, pend, res->flags, default_flag_spec);
1132 }
1133 *p++ = ']';
1134 *p = '\0';
1135
1136 return string_nocheck(buf, end, sym, spec);
1137 }
1138
1139 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1140 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1141 const char *fmt)
1142 {
1143 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1144 negative value, fallback to the default */
1145 char separator;
1146
1147 if (spec.field_width == 0)
1148 /* nothing to print */
1149 return buf;
1150
1151 if (check_pointer(&buf, end, addr, spec))
1152 return buf;
1153
1154 switch (fmt[1]) {
1155 case 'C':
1156 separator = ':';
1157 break;
1158 case 'D':
1159 separator = '-';
1160 break;
1161 case 'N':
1162 separator = 0;
1163 break;
1164 default:
1165 separator = ' ';
1166 break;
1167 }
1168
1169 if (spec.field_width > 0)
1170 len = min_t(int, spec.field_width, 64);
1171
1172 for (i = 0; i < len; ++i) {
1173 if (buf < end)
1174 *buf = hex_asc_hi(addr[i]);
1175 ++buf;
1176 if (buf < end)
1177 *buf = hex_asc_lo(addr[i]);
1178 ++buf;
1179
1180 if (separator && i != len - 1) {
1181 if (buf < end)
1182 *buf = separator;
1183 ++buf;
1184 }
1185 }
1186
1187 return buf;
1188 }
1189
1190 static noinline_for_stack
bitmap_string(char * buf,char * end,unsigned long * bitmap,struct printf_spec spec,const char * fmt)1191 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1192 struct printf_spec spec, const char *fmt)
1193 {
1194 const int CHUNKSZ = 32;
1195 int nr_bits = max_t(int, spec.field_width, 0);
1196 int i, chunksz;
1197 bool first = true;
1198
1199 if (check_pointer(&buf, end, bitmap, spec))
1200 return buf;
1201
1202 /* reused to print numbers */
1203 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1204
1205 chunksz = nr_bits & (CHUNKSZ - 1);
1206 if (chunksz == 0)
1207 chunksz = CHUNKSZ;
1208
1209 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1210 for (; i >= 0; i -= CHUNKSZ) {
1211 u32 chunkmask, val;
1212 int word, bit;
1213
1214 chunkmask = ((1ULL << chunksz) - 1);
1215 word = i / BITS_PER_LONG;
1216 bit = i % BITS_PER_LONG;
1217 val = (bitmap[word] >> bit) & chunkmask;
1218
1219 if (!first) {
1220 if (buf < end)
1221 *buf = ',';
1222 buf++;
1223 }
1224 first = false;
1225
1226 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1227 buf = number(buf, end, val, spec);
1228
1229 chunksz = CHUNKSZ;
1230 }
1231 return buf;
1232 }
1233
1234 static noinline_for_stack
bitmap_list_string(char * buf,char * end,unsigned long * bitmap,struct printf_spec spec,const char * fmt)1235 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1236 struct printf_spec spec, const char *fmt)
1237 {
1238 int nr_bits = max_t(int, spec.field_width, 0);
1239 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1240 int cur, rbot, rtop;
1241 bool first = true;
1242
1243 if (check_pointer(&buf, end, bitmap, spec))
1244 return buf;
1245
1246 rbot = cur = find_first_bit(bitmap, nr_bits);
1247 while (cur < nr_bits) {
1248 rtop = cur;
1249 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1250 if (cur < nr_bits && cur <= rtop + 1)
1251 continue;
1252
1253 if (!first) {
1254 if (buf < end)
1255 *buf = ',';
1256 buf++;
1257 }
1258 first = false;
1259
1260 buf = number(buf, end, rbot, default_dec_spec);
1261 if (rbot < rtop) {
1262 if (buf < end)
1263 *buf = '-';
1264 buf++;
1265
1266 buf = number(buf, end, rtop, default_dec_spec);
1267 }
1268
1269 rbot = cur;
1270 }
1271 return buf;
1272 }
1273
1274 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1275 char *mac_address_string(char *buf, char *end, u8 *addr,
1276 struct printf_spec spec, const char *fmt)
1277 {
1278 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1279 char *p = mac_addr;
1280 int i;
1281 char separator;
1282 bool reversed = false;
1283
1284 if (check_pointer(&buf, end, addr, spec))
1285 return buf;
1286
1287 switch (fmt[1]) {
1288 case 'F':
1289 separator = '-';
1290 break;
1291
1292 case 'R':
1293 reversed = true;
1294 /* fall through */
1295
1296 default:
1297 separator = ':';
1298 break;
1299 }
1300
1301 for (i = 0; i < 6; i++) {
1302 if (reversed)
1303 p = hex_byte_pack(p, addr[5 - i]);
1304 else
1305 p = hex_byte_pack(p, addr[i]);
1306
1307 if (fmt[0] == 'M' && i != 5)
1308 *p++ = separator;
1309 }
1310 *p = '\0';
1311
1312 return string_nocheck(buf, end, mac_addr, spec);
1313 }
1314
1315 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)1316 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1317 {
1318 int i;
1319 bool leading_zeros = (fmt[0] == 'i');
1320 int index;
1321 int step;
1322
1323 switch (fmt[2]) {
1324 case 'h':
1325 #ifdef __BIG_ENDIAN
1326 index = 0;
1327 step = 1;
1328 #else
1329 index = 3;
1330 step = -1;
1331 #endif
1332 break;
1333 case 'l':
1334 index = 3;
1335 step = -1;
1336 break;
1337 case 'n':
1338 case 'b':
1339 default:
1340 index = 0;
1341 step = 1;
1342 break;
1343 }
1344 for (i = 0; i < 4; i++) {
1345 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1346 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1347 if (leading_zeros) {
1348 if (digits < 3)
1349 *p++ = '0';
1350 if (digits < 2)
1351 *p++ = '0';
1352 }
1353 /* reverse the digits in the quad */
1354 while (digits--)
1355 *p++ = temp[digits];
1356 if (i < 3)
1357 *p++ = '.';
1358 index += step;
1359 }
1360 *p = '\0';
1361
1362 return p;
1363 }
1364
1365 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)1366 char *ip6_compressed_string(char *p, const char *addr)
1367 {
1368 int i, j, range;
1369 unsigned char zerolength[8];
1370 int longest = 1;
1371 int colonpos = -1;
1372 u16 word;
1373 u8 hi, lo;
1374 bool needcolon = false;
1375 bool useIPv4;
1376 struct in6_addr in6;
1377
1378 memcpy(&in6, addr, sizeof(struct in6_addr));
1379
1380 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1381
1382 memset(zerolength, 0, sizeof(zerolength));
1383
1384 if (useIPv4)
1385 range = 6;
1386 else
1387 range = 8;
1388
1389 /* find position of longest 0 run */
1390 for (i = 0; i < range; i++) {
1391 for (j = i; j < range; j++) {
1392 if (in6.s6_addr16[j] != 0)
1393 break;
1394 zerolength[i]++;
1395 }
1396 }
1397 for (i = 0; i < range; i++) {
1398 if (zerolength[i] > longest) {
1399 longest = zerolength[i];
1400 colonpos = i;
1401 }
1402 }
1403 if (longest == 1) /* don't compress a single 0 */
1404 colonpos = -1;
1405
1406 /* emit address */
1407 for (i = 0; i < range; i++) {
1408 if (i == colonpos) {
1409 if (needcolon || i == 0)
1410 *p++ = ':';
1411 *p++ = ':';
1412 needcolon = false;
1413 i += longest - 1;
1414 continue;
1415 }
1416 if (needcolon) {
1417 *p++ = ':';
1418 needcolon = false;
1419 }
1420 /* hex u16 without leading 0s */
1421 word = ntohs(in6.s6_addr16[i]);
1422 hi = word >> 8;
1423 lo = word & 0xff;
1424 if (hi) {
1425 if (hi > 0x0f)
1426 p = hex_byte_pack(p, hi);
1427 else
1428 *p++ = hex_asc_lo(hi);
1429 p = hex_byte_pack(p, lo);
1430 }
1431 else if (lo > 0x0f)
1432 p = hex_byte_pack(p, lo);
1433 else
1434 *p++ = hex_asc_lo(lo);
1435 needcolon = true;
1436 }
1437
1438 if (useIPv4) {
1439 if (needcolon)
1440 *p++ = ':';
1441 p = ip4_string(p, &in6.s6_addr[12], "I4");
1442 }
1443 *p = '\0';
1444
1445 return p;
1446 }
1447
1448 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)1449 char *ip6_string(char *p, const char *addr, const char *fmt)
1450 {
1451 int i;
1452
1453 for (i = 0; i < 8; i++) {
1454 p = hex_byte_pack(p, *addr++);
1455 p = hex_byte_pack(p, *addr++);
1456 if (fmt[0] == 'I' && i != 7)
1457 *p++ = ':';
1458 }
1459 *p = '\0';
1460
1461 return p;
1462 }
1463
1464 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1465 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1466 struct printf_spec spec, const char *fmt)
1467 {
1468 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1469
1470 if (fmt[0] == 'I' && fmt[2] == 'c')
1471 ip6_compressed_string(ip6_addr, addr);
1472 else
1473 ip6_string(ip6_addr, addr, fmt);
1474
1475 return string_nocheck(buf, end, ip6_addr, spec);
1476 }
1477
1478 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1479 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1480 struct printf_spec spec, const char *fmt)
1481 {
1482 char ip4_addr[sizeof("255.255.255.255")];
1483
1484 ip4_string(ip4_addr, addr, fmt);
1485
1486 return string_nocheck(buf, end, ip4_addr, spec);
1487 }
1488
1489 static noinline_for_stack
ip6_addr_string_sa(char * buf,char * end,const struct sockaddr_in6 * sa,struct printf_spec spec,const char * fmt)1490 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1491 struct printf_spec spec, const char *fmt)
1492 {
1493 bool have_p = false, have_s = false, have_f = false, have_c = false;
1494 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1495 sizeof(":12345") + sizeof("/123456789") +
1496 sizeof("%1234567890")];
1497 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1498 const u8 *addr = (const u8 *) &sa->sin6_addr;
1499 char fmt6[2] = { fmt[0], '6' };
1500 u8 off = 0;
1501
1502 fmt++;
1503 while (isalpha(*++fmt)) {
1504 switch (*fmt) {
1505 case 'p':
1506 have_p = true;
1507 break;
1508 case 'f':
1509 have_f = true;
1510 break;
1511 case 's':
1512 have_s = true;
1513 break;
1514 case 'c':
1515 have_c = true;
1516 break;
1517 }
1518 }
1519
1520 if (have_p || have_s || have_f) {
1521 *p = '[';
1522 off = 1;
1523 }
1524
1525 if (fmt6[0] == 'I' && have_c)
1526 p = ip6_compressed_string(ip6_addr + off, addr);
1527 else
1528 p = ip6_string(ip6_addr + off, addr, fmt6);
1529
1530 if (have_p || have_s || have_f)
1531 *p++ = ']';
1532
1533 if (have_p) {
1534 *p++ = ':';
1535 p = number(p, pend, ntohs(sa->sin6_port), spec);
1536 }
1537 if (have_f) {
1538 *p++ = '/';
1539 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1540 IPV6_FLOWINFO_MASK), spec);
1541 }
1542 if (have_s) {
1543 *p++ = '%';
1544 p = number(p, pend, sa->sin6_scope_id, spec);
1545 }
1546 *p = '\0';
1547
1548 return string_nocheck(buf, end, ip6_addr, spec);
1549 }
1550
1551 static noinline_for_stack
ip4_addr_string_sa(char * buf,char * end,const struct sockaddr_in * sa,struct printf_spec spec,const char * fmt)1552 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1553 struct printf_spec spec, const char *fmt)
1554 {
1555 bool have_p = false;
1556 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1557 char *pend = ip4_addr + sizeof(ip4_addr);
1558 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1559 char fmt4[3] = { fmt[0], '4', 0 };
1560
1561 fmt++;
1562 while (isalpha(*++fmt)) {
1563 switch (*fmt) {
1564 case 'p':
1565 have_p = true;
1566 break;
1567 case 'h':
1568 case 'l':
1569 case 'n':
1570 case 'b':
1571 fmt4[2] = *fmt;
1572 break;
1573 }
1574 }
1575
1576 p = ip4_string(ip4_addr, addr, fmt4);
1577 if (have_p) {
1578 *p++ = ':';
1579 p = number(p, pend, ntohs(sa->sin_port), spec);
1580 }
1581 *p = '\0';
1582
1583 return string_nocheck(buf, end, ip4_addr, spec);
1584 }
1585
1586 static noinline_for_stack
ip_addr_string(char * buf,char * end,const void * ptr,struct printf_spec spec,const char * fmt)1587 char *ip_addr_string(char *buf, char *end, const void *ptr,
1588 struct printf_spec spec, const char *fmt)
1589 {
1590 char *err_fmt_msg;
1591
1592 if (check_pointer(&buf, end, ptr, spec))
1593 return buf;
1594
1595 switch (fmt[1]) {
1596 case '6':
1597 return ip6_addr_string(buf, end, ptr, spec, fmt);
1598 case '4':
1599 return ip4_addr_string(buf, end, ptr, spec, fmt);
1600 case 'S': {
1601 const union {
1602 struct sockaddr raw;
1603 struct sockaddr_in v4;
1604 struct sockaddr_in6 v6;
1605 } *sa = ptr;
1606
1607 switch (sa->raw.sa_family) {
1608 case AF_INET:
1609 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1610 case AF_INET6:
1611 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1612 default:
1613 return error_string(buf, end, "(einval)", spec);
1614 }}
1615 }
1616
1617 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1618 return error_string(buf, end, err_fmt_msg, spec);
1619 }
1620
1621 static noinline_for_stack
escaped_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1622 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1623 const char *fmt)
1624 {
1625 bool found = true;
1626 int count = 1;
1627 unsigned int flags = 0;
1628 int len;
1629
1630 if (spec.field_width == 0)
1631 return buf; /* nothing to print */
1632
1633 if (check_pointer(&buf, end, addr, spec))
1634 return buf;
1635
1636 do {
1637 switch (fmt[count++]) {
1638 case 'a':
1639 flags |= ESCAPE_ANY;
1640 break;
1641 case 'c':
1642 flags |= ESCAPE_SPECIAL;
1643 break;
1644 case 'h':
1645 flags |= ESCAPE_HEX;
1646 break;
1647 case 'n':
1648 flags |= ESCAPE_NULL;
1649 break;
1650 case 'o':
1651 flags |= ESCAPE_OCTAL;
1652 break;
1653 case 'p':
1654 flags |= ESCAPE_NP;
1655 break;
1656 case 's':
1657 flags |= ESCAPE_SPACE;
1658 break;
1659 default:
1660 found = false;
1661 break;
1662 }
1663 } while (found);
1664
1665 if (!flags)
1666 flags = ESCAPE_ANY_NP;
1667
1668 len = spec.field_width < 0 ? 1 : spec.field_width;
1669
1670 /*
1671 * string_escape_mem() writes as many characters as it can to
1672 * the given buffer, and returns the total size of the output
1673 * had the buffer been big enough.
1674 */
1675 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1676
1677 return buf;
1678 }
1679
va_format(char * buf,char * end,struct va_format * va_fmt,struct printf_spec spec,const char * fmt)1680 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1681 struct printf_spec spec, const char *fmt)
1682 {
1683 va_list va;
1684
1685 if (check_pointer(&buf, end, va_fmt, spec))
1686 return buf;
1687
1688 va_copy(va, *va_fmt->va);
1689 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1690 va_end(va);
1691
1692 return buf;
1693 }
1694
1695 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1696 char *uuid_string(char *buf, char *end, const u8 *addr,
1697 struct printf_spec spec, const char *fmt)
1698 {
1699 char uuid[UUID_STRING_LEN + 1];
1700 char *p = uuid;
1701 int i;
1702 const u8 *index = uuid_index;
1703 bool uc = false;
1704
1705 if (check_pointer(&buf, end, addr, spec))
1706 return buf;
1707
1708 switch (*(++fmt)) {
1709 case 'L':
1710 uc = true;
1711 /* fall through */
1712 case 'l':
1713 index = guid_index;
1714 break;
1715 case 'B':
1716 uc = true;
1717 break;
1718 }
1719
1720 for (i = 0; i < 16; i++) {
1721 if (uc)
1722 p = hex_byte_pack_upper(p, addr[index[i]]);
1723 else
1724 p = hex_byte_pack(p, addr[index[i]]);
1725 switch (i) {
1726 case 3:
1727 case 5:
1728 case 7:
1729 case 9:
1730 *p++ = '-';
1731 break;
1732 }
1733 }
1734
1735 *p = 0;
1736
1737 return string_nocheck(buf, end, uuid, spec);
1738 }
1739
1740 static noinline_for_stack
netdev_bits(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1741 char *netdev_bits(char *buf, char *end, const void *addr,
1742 struct printf_spec spec, const char *fmt)
1743 {
1744 unsigned long long num;
1745 int size;
1746
1747 if (check_pointer(&buf, end, addr, spec))
1748 return buf;
1749
1750 switch (fmt[1]) {
1751 case 'F':
1752 num = *(const netdev_features_t *)addr;
1753 size = sizeof(netdev_features_t);
1754 break;
1755 default:
1756 return error_string(buf, end, "(%pN?)", spec);
1757 }
1758
1759 return special_hex_number(buf, end, num, size);
1760 }
1761
1762 static noinline_for_stack
address_val(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1763 char *address_val(char *buf, char *end, const void *addr,
1764 struct printf_spec spec, const char *fmt)
1765 {
1766 unsigned long long num;
1767 int size;
1768
1769 if (check_pointer(&buf, end, addr, spec))
1770 return buf;
1771
1772 switch (fmt[1]) {
1773 case 'd':
1774 num = *(const dma_addr_t *)addr;
1775 size = sizeof(dma_addr_t);
1776 break;
1777 case 'p':
1778 default:
1779 num = *(const phys_addr_t *)addr;
1780 size = sizeof(phys_addr_t);
1781 break;
1782 }
1783
1784 return special_hex_number(buf, end, num, size);
1785 }
1786
1787 static noinline_for_stack
date_str(char * buf,char * end,const struct rtc_time * tm,bool r)1788 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1789 {
1790 int year = tm->tm_year + (r ? 0 : 1900);
1791 int mon = tm->tm_mon + (r ? 0 : 1);
1792
1793 buf = number(buf, end, year, default_dec04_spec);
1794 if (buf < end)
1795 *buf = '-';
1796 buf++;
1797
1798 buf = number(buf, end, mon, default_dec02_spec);
1799 if (buf < end)
1800 *buf = '-';
1801 buf++;
1802
1803 return number(buf, end, tm->tm_mday, default_dec02_spec);
1804 }
1805
1806 static noinline_for_stack
time_str(char * buf,char * end,const struct rtc_time * tm,bool r)1807 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1808 {
1809 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1810 if (buf < end)
1811 *buf = ':';
1812 buf++;
1813
1814 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1815 if (buf < end)
1816 *buf = ':';
1817 buf++;
1818
1819 return number(buf, end, tm->tm_sec, default_dec02_spec);
1820 }
1821
1822 static noinline_for_stack
rtc_str(char * buf,char * end,const struct rtc_time * tm,struct printf_spec spec,const char * fmt)1823 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1824 struct printf_spec spec, const char *fmt)
1825 {
1826 bool have_t = true, have_d = true;
1827 bool raw = false;
1828 int count = 2;
1829
1830 if (check_pointer(&buf, end, tm, spec))
1831 return buf;
1832
1833 switch (fmt[count]) {
1834 case 'd':
1835 have_t = false;
1836 count++;
1837 break;
1838 case 't':
1839 have_d = false;
1840 count++;
1841 break;
1842 }
1843
1844 raw = fmt[count] == 'r';
1845
1846 if (have_d)
1847 buf = date_str(buf, end, tm, raw);
1848 if (have_d && have_t) {
1849 /* Respect ISO 8601 */
1850 if (buf < end)
1851 *buf = 'T';
1852 buf++;
1853 }
1854 if (have_t)
1855 buf = time_str(buf, end, tm, raw);
1856
1857 return buf;
1858 }
1859
1860 static noinline_for_stack
time64_str(char * buf,char * end,const time64_t time,struct printf_spec spec,const char * fmt)1861 char *time64_str(char *buf, char *end, const time64_t time,
1862 struct printf_spec spec, const char *fmt)
1863 {
1864 struct rtc_time rtc_time;
1865 struct tm tm;
1866
1867 time64_to_tm(time, 0, &tm);
1868
1869 rtc_time.tm_sec = tm.tm_sec;
1870 rtc_time.tm_min = tm.tm_min;
1871 rtc_time.tm_hour = tm.tm_hour;
1872 rtc_time.tm_mday = tm.tm_mday;
1873 rtc_time.tm_mon = tm.tm_mon;
1874 rtc_time.tm_year = tm.tm_year;
1875 rtc_time.tm_wday = tm.tm_wday;
1876 rtc_time.tm_yday = tm.tm_yday;
1877
1878 rtc_time.tm_isdst = 0;
1879
1880 return rtc_str(buf, end, &rtc_time, spec, fmt);
1881 }
1882
1883 static noinline_for_stack
time_and_date(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)1884 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1885 const char *fmt)
1886 {
1887 switch (fmt[1]) {
1888 case 'R':
1889 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1890 case 'T':
1891 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1892 default:
1893 return error_string(buf, end, "(%pt?)", spec);
1894 }
1895 }
1896
1897 static noinline_for_stack
clock(char * buf,char * end,struct clk * clk,struct printf_spec spec,const char * fmt)1898 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1899 const char *fmt)
1900 {
1901 if (!IS_ENABLED(CONFIG_HAVE_CLK))
1902 return error_string(buf, end, "(%pC?)", spec);
1903
1904 if (check_pointer(&buf, end, clk, spec))
1905 return buf;
1906
1907 switch (fmt[1]) {
1908 case 'n':
1909 default:
1910 #ifdef CONFIG_COMMON_CLK
1911 return string(buf, end, __clk_get_name(clk), spec);
1912 #else
1913 return ptr_to_id(buf, end, clk, spec);
1914 #endif
1915 }
1916 }
1917
1918 static
format_flags(char * buf,char * end,unsigned long flags,const struct trace_print_flags * names)1919 char *format_flags(char *buf, char *end, unsigned long flags,
1920 const struct trace_print_flags *names)
1921 {
1922 unsigned long mask;
1923
1924 for ( ; flags && names->name; names++) {
1925 mask = names->mask;
1926 if ((flags & mask) != mask)
1927 continue;
1928
1929 buf = string(buf, end, names->name, default_str_spec);
1930
1931 flags &= ~mask;
1932 if (flags) {
1933 if (buf < end)
1934 *buf = '|';
1935 buf++;
1936 }
1937 }
1938
1939 if (flags)
1940 buf = number(buf, end, flags, default_flag_spec);
1941
1942 return buf;
1943 }
1944
1945 static noinline_for_stack
flags_string(char * buf,char * end,void * flags_ptr,struct printf_spec spec,const char * fmt)1946 char *flags_string(char *buf, char *end, void *flags_ptr,
1947 struct printf_spec spec, const char *fmt)
1948 {
1949 unsigned long flags;
1950 const struct trace_print_flags *names;
1951
1952 if (check_pointer(&buf, end, flags_ptr, spec))
1953 return buf;
1954
1955 switch (fmt[1]) {
1956 case 'p':
1957 flags = *(unsigned long *)flags_ptr;
1958 /* Remove zone id */
1959 flags &= (1UL << NR_PAGEFLAGS) - 1;
1960 names = pageflag_names;
1961 break;
1962 case 'v':
1963 flags = *(unsigned long *)flags_ptr;
1964 names = vmaflag_names;
1965 break;
1966 case 'g':
1967 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
1968 names = gfpflag_names;
1969 break;
1970 default:
1971 return error_string(buf, end, "(%pG?)", spec);
1972 }
1973
1974 return format_flags(buf, end, flags, names);
1975 }
1976
1977 static noinline_for_stack
fwnode_full_name_string(struct fwnode_handle * fwnode,char * buf,char * end)1978 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
1979 char *end)
1980 {
1981 int depth;
1982
1983 /* Loop starting from the root node to the current node. */
1984 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
1985 struct fwnode_handle *__fwnode =
1986 fwnode_get_nth_parent(fwnode, depth);
1987
1988 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
1989 default_str_spec);
1990 buf = string(buf, end, fwnode_get_name(__fwnode),
1991 default_str_spec);
1992
1993 fwnode_handle_put(__fwnode);
1994 }
1995
1996 return buf;
1997 }
1998
1999 static noinline_for_stack
device_node_string(char * buf,char * end,struct device_node * dn,struct printf_spec spec,const char * fmt)2000 char *device_node_string(char *buf, char *end, struct device_node *dn,
2001 struct printf_spec spec, const char *fmt)
2002 {
2003 char tbuf[sizeof("xxxx") + 1];
2004 const char *p;
2005 int ret;
2006 char *buf_start = buf;
2007 struct property *prop;
2008 bool has_mult, pass;
2009
2010 struct printf_spec str_spec = spec;
2011 str_spec.field_width = -1;
2012
2013 if (fmt[0] != 'F')
2014 return error_string(buf, end, "(%pO?)", spec);
2015
2016 if (!IS_ENABLED(CONFIG_OF))
2017 return error_string(buf, end, "(%pOF?)", spec);
2018
2019 if (check_pointer(&buf, end, dn, spec))
2020 return buf;
2021
2022 /* simple case without anything any more format specifiers */
2023 fmt++;
2024 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2025 fmt = "f";
2026
2027 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2028 int precision;
2029 if (pass) {
2030 if (buf < end)
2031 *buf = ':';
2032 buf++;
2033 }
2034
2035 switch (*fmt) {
2036 case 'f': /* full_name */
2037 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2038 end);
2039 break;
2040 case 'n': /* name */
2041 p = fwnode_get_name(of_fwnode_handle(dn));
2042 precision = str_spec.precision;
2043 str_spec.precision = strchrnul(p, '@') - p;
2044 buf = string(buf, end, p, str_spec);
2045 str_spec.precision = precision;
2046 break;
2047 case 'p': /* phandle */
2048 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2049 break;
2050 case 'P': /* path-spec */
2051 p = fwnode_get_name(of_fwnode_handle(dn));
2052 if (!p[1])
2053 p = "/";
2054 buf = string(buf, end, p, str_spec);
2055 break;
2056 case 'F': /* flags */
2057 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2058 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2059 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2060 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2061 tbuf[4] = 0;
2062 buf = string_nocheck(buf, end, tbuf, str_spec);
2063 break;
2064 case 'c': /* major compatible string */
2065 ret = of_property_read_string(dn, "compatible", &p);
2066 if (!ret)
2067 buf = string(buf, end, p, str_spec);
2068 break;
2069 case 'C': /* full compatible string */
2070 has_mult = false;
2071 of_property_for_each_string(dn, "compatible", prop, p) {
2072 if (has_mult)
2073 buf = string_nocheck(buf, end, ",", str_spec);
2074 buf = string_nocheck(buf, end, "\"", str_spec);
2075 buf = string(buf, end, p, str_spec);
2076 buf = string_nocheck(buf, end, "\"", str_spec);
2077
2078 has_mult = true;
2079 }
2080 break;
2081 default:
2082 break;
2083 }
2084 }
2085
2086 return widen_string(buf, buf - buf_start, end, spec);
2087 }
2088
2089 static noinline_for_stack
fwnode_string(char * buf,char * end,struct fwnode_handle * fwnode,struct printf_spec spec,const char * fmt)2090 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2091 struct printf_spec spec, const char *fmt)
2092 {
2093 struct printf_spec str_spec = spec;
2094 char *buf_start = buf;
2095
2096 str_spec.field_width = -1;
2097
2098 if (*fmt != 'w')
2099 return error_string(buf, end, "(%pf?)", spec);
2100
2101 if (check_pointer(&buf, end, fwnode, spec))
2102 return buf;
2103
2104 fmt++;
2105
2106 switch (*fmt) {
2107 case 'P': /* name */
2108 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2109 break;
2110 case 'f': /* full_name */
2111 default:
2112 buf = fwnode_full_name_string(fwnode, buf, end);
2113 break;
2114 }
2115
2116 return widen_string(buf, buf - buf_start, end, spec);
2117 }
2118
2119 /*
2120 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2121 * by an extra set of alphanumeric characters that are extended format
2122 * specifiers.
2123 *
2124 * Please update scripts/checkpatch.pl when adding/removing conversion
2125 * characters. (Search for "check for vsprintf extension").
2126 *
2127 * Right now we handle:
2128 *
2129 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2130 * - 's' For symbolic direct pointers (or function descriptors) without offset
2131 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2132 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2133 * %ps and %pS. Be careful when re-using these specifiers.
2134 * - 'B' For backtraced symbolic direct pointers with offset
2135 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2136 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2137 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2138 * width which must be explicitly specified either as part of the
2139 * format string '%32b[l]' or through '%*b[l]', [l] selects
2140 * range-list format instead of hex format
2141 * - 'M' For a 6-byte MAC address, it prints the address in the
2142 * usual colon-separated hex notation
2143 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2144 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2145 * with a dash-separated hex notation
2146 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2147 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2148 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2149 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2150 * [S][pfs]
2151 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2152 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2153 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2154 * IPv6 omits the colons (01020304...0f)
2155 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2156 * [S][pfs]
2157 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2158 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2159 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2160 * - 'I[6S]c' for IPv6 addresses printed as specified by
2161 * https://tools.ietf.org/html/rfc5952
2162 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2163 * of the following flags (see string_escape_mem() for the
2164 * details):
2165 * a - ESCAPE_ANY
2166 * c - ESCAPE_SPECIAL
2167 * h - ESCAPE_HEX
2168 * n - ESCAPE_NULL
2169 * o - ESCAPE_OCTAL
2170 * p - ESCAPE_NP
2171 * s - ESCAPE_SPACE
2172 * By default ESCAPE_ANY_NP is used.
2173 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2174 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2175 * Options for %pU are:
2176 * b big endian lower case hex (default)
2177 * B big endian UPPER case hex
2178 * l little endian lower case hex
2179 * L little endian UPPER case hex
2180 * big endian output byte order is:
2181 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2182 * little endian output byte order is:
2183 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2184 * - 'V' For a struct va_format which contains a format string * and va_list *,
2185 * call vsnprintf(->format, *->va_list).
2186 * Implements a "recursive vsnprintf".
2187 * Do not use this feature without some mechanism to verify the
2188 * correctness of the format string and va_list arguments.
2189 * - 'K' For a kernel pointer that should be hidden from unprivileged users
2190 * - 'NF' For a netdev_features_t
2191 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2192 * a certain separator (' ' by default):
2193 * C colon
2194 * D dash
2195 * N no separator
2196 * The maximum supported length is 64 bytes of the input. Consider
2197 * to use print_hex_dump() for the larger input.
2198 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2199 * (default assumed to be phys_addr_t, passed by reference)
2200 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2201 * - 'D[234]' Same as 'd' but for a struct file
2202 * - 'g' For block_device name (gendisk + partition number)
2203 * - 't[RT][dt][r]' For time and date as represented by:
2204 * R struct rtc_time
2205 * T time64_t
2206 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2207 * (legacy clock framework) of the clock
2208 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2209 * (legacy clock framework) of the clock
2210 * - 'G' For flags to be printed as a collection of symbolic strings that would
2211 * construct the specific value. Supported flags given by option:
2212 * p page flags (see struct page) given as pointer to unsigned long
2213 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2214 * v vma flags (VM_*) given as pointer to unsigned long
2215 * - 'OF[fnpPcCF]' For a device tree object
2216 * Without any optional arguments prints the full_name
2217 * f device node full_name
2218 * n device node name
2219 * p device node phandle
2220 * P device node path spec (name + @unit)
2221 * F device node flags
2222 * c major compatible string
2223 * C full compatible string
2224 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2225 * Without an option prints the full name of the node
2226 * f full name
2227 * P node name, including a possible unit address
2228 * - 'x' For printing the address. Equivalent to "%lx".
2229 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2230 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2231 * or user (u) memory to probe, and:
2232 * s a string, equivalent to "%s" on direct vsnprintf() use
2233 *
2234 * ** When making changes please also update:
2235 * Documentation/core-api/printk-formats.rst
2236 *
2237 * Note: The default behaviour (unadorned %p) is to hash the address,
2238 * rendering it useful as a unique identifier.
2239 */
2240 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2241 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2242 struct printf_spec spec)
2243 {
2244 switch (*fmt) {
2245 case 'S':
2246 case 's':
2247 ptr = dereference_symbol_descriptor(ptr);
2248 /* fall through */
2249 case 'B':
2250 return symbol_string(buf, end, ptr, spec, fmt);
2251 case 'R':
2252 case 'r':
2253 return resource_string(buf, end, ptr, spec, fmt);
2254 case 'h':
2255 return hex_string(buf, end, ptr, spec, fmt);
2256 case 'b':
2257 switch (fmt[1]) {
2258 case 'l':
2259 return bitmap_list_string(buf, end, ptr, spec, fmt);
2260 default:
2261 return bitmap_string(buf, end, ptr, spec, fmt);
2262 }
2263 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2264 case 'm': /* Contiguous: 000102030405 */
2265 /* [mM]F (FDDI) */
2266 /* [mM]R (Reverse order; Bluetooth) */
2267 return mac_address_string(buf, end, ptr, spec, fmt);
2268 case 'I': /* Formatted IP supported
2269 * 4: 1.2.3.4
2270 * 6: 0001:0203:...:0708
2271 * 6c: 1::708 or 1::1.2.3.4
2272 */
2273 case 'i': /* Contiguous:
2274 * 4: 001.002.003.004
2275 * 6: 000102...0f
2276 */
2277 return ip_addr_string(buf, end, ptr, spec, fmt);
2278 case 'E':
2279 return escaped_string(buf, end, ptr, spec, fmt);
2280 case 'U':
2281 return uuid_string(buf, end, ptr, spec, fmt);
2282 case 'V':
2283 return va_format(buf, end, ptr, spec, fmt);
2284 case 'K':
2285 return restricted_pointer(buf, end, ptr, spec);
2286 case 'N':
2287 return netdev_bits(buf, end, ptr, spec, fmt);
2288 case 'a':
2289 return address_val(buf, end, ptr, spec, fmt);
2290 case 'd':
2291 return dentry_name(buf, end, ptr, spec, fmt);
2292 case 't':
2293 return time_and_date(buf, end, ptr, spec, fmt);
2294 case 'C':
2295 return clock(buf, end, ptr, spec, fmt);
2296 case 'D':
2297 return file_dentry_name(buf, end, ptr, spec, fmt);
2298 #ifdef CONFIG_BLOCK
2299 case 'g':
2300 return bdev_name(buf, end, ptr, spec, fmt);
2301 #endif
2302
2303 case 'G':
2304 return flags_string(buf, end, ptr, spec, fmt);
2305 case 'O':
2306 return device_node_string(buf, end, ptr, spec, fmt + 1);
2307 case 'f':
2308 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2309 case 'x':
2310 return pointer_string(buf, end, ptr, spec);
2311 case 'e':
2312 /* %pe with a non-ERR_PTR gets treated as plain %p */
2313 if (!IS_ERR(ptr))
2314 break;
2315 return err_ptr(buf, end, ptr, spec);
2316 case 'u':
2317 case 'k':
2318 switch (fmt[1]) {
2319 case 's':
2320 return string(buf, end, ptr, spec);
2321 default:
2322 return error_string(buf, end, "(einval)", spec);
2323 }
2324 }
2325
2326 /* default is to _not_ leak addresses, hash before printing */
2327 return ptr_to_id(buf, end, ptr, spec);
2328 }
2329
2330 /*
2331 * Helper function to decode printf style format.
2332 * Each call decode a token from the format and return the
2333 * number of characters read (or likely the delta where it wants
2334 * to go on the next call).
2335 * The decoded token is returned through the parameters
2336 *
2337 * 'h', 'l', or 'L' for integer fields
2338 * 'z' support added 23/7/1999 S.H.
2339 * 'z' changed to 'Z' --davidm 1/25/99
2340 * 'Z' changed to 'z' --adobriyan 2017-01-25
2341 * 't' added for ptrdiff_t
2342 *
2343 * @fmt: the format string
2344 * @type of the token returned
2345 * @flags: various flags such as +, -, # tokens..
2346 * @field_width: overwritten width
2347 * @base: base of the number (octal, hex, ...)
2348 * @precision: precision of a number
2349 * @qualifier: qualifier of a number (long, size_t, ...)
2350 */
2351 static noinline_for_stack
format_decode(const char * fmt,struct printf_spec * spec)2352 int format_decode(const char *fmt, struct printf_spec *spec)
2353 {
2354 const char *start = fmt;
2355 char qualifier;
2356
2357 /* we finished early by reading the field width */
2358 if (spec->type == FORMAT_TYPE_WIDTH) {
2359 if (spec->field_width < 0) {
2360 spec->field_width = -spec->field_width;
2361 spec->flags |= LEFT;
2362 }
2363 spec->type = FORMAT_TYPE_NONE;
2364 goto precision;
2365 }
2366
2367 /* we finished early by reading the precision */
2368 if (spec->type == FORMAT_TYPE_PRECISION) {
2369 if (spec->precision < 0)
2370 spec->precision = 0;
2371
2372 spec->type = FORMAT_TYPE_NONE;
2373 goto qualifier;
2374 }
2375
2376 /* By default */
2377 spec->type = FORMAT_TYPE_NONE;
2378
2379 for (; *fmt ; ++fmt) {
2380 if (*fmt == '%')
2381 break;
2382 }
2383
2384 /* Return the current non-format string */
2385 if (fmt != start || !*fmt)
2386 return fmt - start;
2387
2388 /* Process flags */
2389 spec->flags = 0;
2390
2391 while (1) { /* this also skips first '%' */
2392 bool found = true;
2393
2394 ++fmt;
2395
2396 switch (*fmt) {
2397 case '-': spec->flags |= LEFT; break;
2398 case '+': spec->flags |= PLUS; break;
2399 case ' ': spec->flags |= SPACE; break;
2400 case '#': spec->flags |= SPECIAL; break;
2401 case '0': spec->flags |= ZEROPAD; break;
2402 default: found = false;
2403 }
2404
2405 if (!found)
2406 break;
2407 }
2408
2409 /* get field width */
2410 spec->field_width = -1;
2411
2412 if (isdigit(*fmt))
2413 spec->field_width = skip_atoi(&fmt);
2414 else if (*fmt == '*') {
2415 /* it's the next argument */
2416 spec->type = FORMAT_TYPE_WIDTH;
2417 return ++fmt - start;
2418 }
2419
2420 precision:
2421 /* get the precision */
2422 spec->precision = -1;
2423 if (*fmt == '.') {
2424 ++fmt;
2425 if (isdigit(*fmt)) {
2426 spec->precision = skip_atoi(&fmt);
2427 if (spec->precision < 0)
2428 spec->precision = 0;
2429 } else if (*fmt == '*') {
2430 /* it's the next argument */
2431 spec->type = FORMAT_TYPE_PRECISION;
2432 return ++fmt - start;
2433 }
2434 }
2435
2436 qualifier:
2437 /* get the conversion qualifier */
2438 qualifier = 0;
2439 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2440 *fmt == 'z' || *fmt == 't') {
2441 qualifier = *fmt++;
2442 if (unlikely(qualifier == *fmt)) {
2443 if (qualifier == 'l') {
2444 qualifier = 'L';
2445 ++fmt;
2446 } else if (qualifier == 'h') {
2447 qualifier = 'H';
2448 ++fmt;
2449 }
2450 }
2451 }
2452
2453 /* default base */
2454 spec->base = 10;
2455 switch (*fmt) {
2456 case 'c':
2457 spec->type = FORMAT_TYPE_CHAR;
2458 return ++fmt - start;
2459
2460 case 's':
2461 spec->type = FORMAT_TYPE_STR;
2462 return ++fmt - start;
2463
2464 case 'p':
2465 spec->type = FORMAT_TYPE_PTR;
2466 return ++fmt - start;
2467
2468 case '%':
2469 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2470 return ++fmt - start;
2471
2472 /* integer number formats - set up the flags and "break" */
2473 case 'o':
2474 spec->base = 8;
2475 break;
2476
2477 case 'x':
2478 spec->flags |= SMALL;
2479 /* fall through */
2480
2481 case 'X':
2482 spec->base = 16;
2483 break;
2484
2485 case 'd':
2486 case 'i':
2487 spec->flags |= SIGN;
2488 case 'u':
2489 break;
2490
2491 case 'n':
2492 /*
2493 * Since %n poses a greater security risk than
2494 * utility, treat it as any other invalid or
2495 * unsupported format specifier.
2496 */
2497 /* fall through */
2498
2499 default:
2500 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2501 spec->type = FORMAT_TYPE_INVALID;
2502 return fmt - start;
2503 }
2504
2505 if (qualifier == 'L')
2506 spec->type = FORMAT_TYPE_LONG_LONG;
2507 else if (qualifier == 'l') {
2508 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2509 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2510 } else if (qualifier == 'z') {
2511 spec->type = FORMAT_TYPE_SIZE_T;
2512 } else if (qualifier == 't') {
2513 spec->type = FORMAT_TYPE_PTRDIFF;
2514 } else if (qualifier == 'H') {
2515 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2516 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2517 } else if (qualifier == 'h') {
2518 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2519 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2520 } else {
2521 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2522 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2523 }
2524
2525 return ++fmt - start;
2526 }
2527
2528 static void
set_field_width(struct printf_spec * spec,int width)2529 set_field_width(struct printf_spec *spec, int width)
2530 {
2531 spec->field_width = width;
2532 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2533 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2534 }
2535 }
2536
2537 static void
set_precision(struct printf_spec * spec,int prec)2538 set_precision(struct printf_spec *spec, int prec)
2539 {
2540 spec->precision = prec;
2541 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2542 spec->precision = clamp(prec, 0, PRECISION_MAX);
2543 }
2544 }
2545
2546 /**
2547 * vsnprintf - Format a string and place it in a buffer
2548 * @buf: The buffer to place the result into
2549 * @size: The size of the buffer, including the trailing null space
2550 * @fmt: The format string to use
2551 * @args: Arguments for the format string
2552 *
2553 * This function generally follows C99 vsnprintf, but has some
2554 * extensions and a few limitations:
2555 *
2556 * - ``%n`` is unsupported
2557 * - ``%p*`` is handled by pointer()
2558 *
2559 * See pointer() or Documentation/core-api/printk-formats.rst for more
2560 * extensive description.
2561 *
2562 * **Please update the documentation in both places when making changes**
2563 *
2564 * The return value is the number of characters which would
2565 * be generated for the given input, excluding the trailing
2566 * '\0', as per ISO C99. If you want to have the exact
2567 * number of characters written into @buf as return value
2568 * (not including the trailing '\0'), use vscnprintf(). If the
2569 * return is greater than or equal to @size, the resulting
2570 * string is truncated.
2571 *
2572 * If you're not already dealing with a va_list consider using snprintf().
2573 */
vsnprintf(char * buf,size_t size,const char * fmt,va_list args)2574 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2575 {
2576 unsigned long long num;
2577 char *str, *end;
2578 struct printf_spec spec = {0};
2579
2580 /* Reject out-of-range values early. Large positive sizes are
2581 used for unknown buffer sizes. */
2582 if (WARN_ON_ONCE(size > INT_MAX))
2583 return 0;
2584
2585 str = buf;
2586 end = buf + size;
2587
2588 /* Make sure end is always >= buf */
2589 if (end < buf) {
2590 end = ((void *)-1);
2591 size = end - buf;
2592 }
2593
2594 while (*fmt) {
2595 const char *old_fmt = fmt;
2596 int read = format_decode(fmt, &spec);
2597
2598 fmt += read;
2599
2600 switch (spec.type) {
2601 case FORMAT_TYPE_NONE: {
2602 int copy = read;
2603 if (str < end) {
2604 if (copy > end - str)
2605 copy = end - str;
2606 memcpy(str, old_fmt, copy);
2607 }
2608 str += read;
2609 break;
2610 }
2611
2612 case FORMAT_TYPE_WIDTH:
2613 set_field_width(&spec, va_arg(args, int));
2614 break;
2615
2616 case FORMAT_TYPE_PRECISION:
2617 set_precision(&spec, va_arg(args, int));
2618 break;
2619
2620 case FORMAT_TYPE_CHAR: {
2621 char c;
2622
2623 if (!(spec.flags & LEFT)) {
2624 while (--spec.field_width > 0) {
2625 if (str < end)
2626 *str = ' ';
2627 ++str;
2628
2629 }
2630 }
2631 c = (unsigned char) va_arg(args, int);
2632 if (str < end)
2633 *str = c;
2634 ++str;
2635 while (--spec.field_width > 0) {
2636 if (str < end)
2637 *str = ' ';
2638 ++str;
2639 }
2640 break;
2641 }
2642
2643 case FORMAT_TYPE_STR:
2644 str = string(str, end, va_arg(args, char *), spec);
2645 break;
2646
2647 case FORMAT_TYPE_PTR:
2648 str = pointer(fmt, str, end, va_arg(args, void *),
2649 spec);
2650 while (isalnum(*fmt))
2651 fmt++;
2652 break;
2653
2654 case FORMAT_TYPE_PERCENT_CHAR:
2655 if (str < end)
2656 *str = '%';
2657 ++str;
2658 break;
2659
2660 case FORMAT_TYPE_INVALID:
2661 /*
2662 * Presumably the arguments passed gcc's type
2663 * checking, but there is no safe or sane way
2664 * for us to continue parsing the format and
2665 * fetching from the va_list; the remaining
2666 * specifiers and arguments would be out of
2667 * sync.
2668 */
2669 goto out;
2670
2671 default:
2672 switch (spec.type) {
2673 case FORMAT_TYPE_LONG_LONG:
2674 num = va_arg(args, long long);
2675 break;
2676 case FORMAT_TYPE_ULONG:
2677 num = va_arg(args, unsigned long);
2678 break;
2679 case FORMAT_TYPE_LONG:
2680 num = va_arg(args, long);
2681 break;
2682 case FORMAT_TYPE_SIZE_T:
2683 if (spec.flags & SIGN)
2684 num = va_arg(args, ssize_t);
2685 else
2686 num = va_arg(args, size_t);
2687 break;
2688 case FORMAT_TYPE_PTRDIFF:
2689 num = va_arg(args, ptrdiff_t);
2690 break;
2691 case FORMAT_TYPE_UBYTE:
2692 num = (unsigned char) va_arg(args, int);
2693 break;
2694 case FORMAT_TYPE_BYTE:
2695 num = (signed char) va_arg(args, int);
2696 break;
2697 case FORMAT_TYPE_USHORT:
2698 num = (unsigned short) va_arg(args, int);
2699 break;
2700 case FORMAT_TYPE_SHORT:
2701 num = (short) va_arg(args, int);
2702 break;
2703 case FORMAT_TYPE_INT:
2704 num = (int) va_arg(args, int);
2705 break;
2706 default:
2707 num = va_arg(args, unsigned int);
2708 }
2709
2710 str = number(str, end, num, spec);
2711 }
2712 }
2713
2714 out:
2715 if (size > 0) {
2716 if (str < end)
2717 *str = '\0';
2718 else
2719 end[-1] = '\0';
2720 }
2721
2722 /* the trailing null byte doesn't count towards the total */
2723 return str-buf;
2724
2725 }
2726 EXPORT_SYMBOL(vsnprintf);
2727
2728 /**
2729 * vscnprintf - Format a string and place it in a buffer
2730 * @buf: The buffer to place the result into
2731 * @size: The size of the buffer, including the trailing null space
2732 * @fmt: The format string to use
2733 * @args: Arguments for the format string
2734 *
2735 * The return value is the number of characters which have been written into
2736 * the @buf not including the trailing '\0'. If @size is == 0 the function
2737 * returns 0.
2738 *
2739 * If you're not already dealing with a va_list consider using scnprintf().
2740 *
2741 * See the vsnprintf() documentation for format string extensions over C99.
2742 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)2743 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2744 {
2745 int i;
2746
2747 i = vsnprintf(buf, size, fmt, args);
2748
2749 if (likely(i < size))
2750 return i;
2751 if (size != 0)
2752 return size - 1;
2753 return 0;
2754 }
2755 EXPORT_SYMBOL(vscnprintf);
2756
2757 /**
2758 * snprintf - Format a string and place it in a buffer
2759 * @buf: The buffer to place the result into
2760 * @size: The size of the buffer, including the trailing null space
2761 * @fmt: The format string to use
2762 * @...: Arguments for the format string
2763 *
2764 * The return value is the number of characters which would be
2765 * generated for the given input, excluding the trailing null,
2766 * as per ISO C99. If the return is greater than or equal to
2767 * @size, the resulting string is truncated.
2768 *
2769 * See the vsnprintf() documentation for format string extensions over C99.
2770 */
snprintf(char * buf,size_t size,const char * fmt,...)2771 int snprintf(char *buf, size_t size, const char *fmt, ...)
2772 {
2773 va_list args;
2774 int i;
2775
2776 va_start(args, fmt);
2777 i = vsnprintf(buf, size, fmt, args);
2778 va_end(args);
2779
2780 return i;
2781 }
2782 EXPORT_SYMBOL(snprintf);
2783
2784 /**
2785 * scnprintf - Format a string and place it in a buffer
2786 * @buf: The buffer to place the result into
2787 * @size: The size of the buffer, including the trailing null space
2788 * @fmt: The format string to use
2789 * @...: Arguments for the format string
2790 *
2791 * The return value is the number of characters written into @buf not including
2792 * the trailing '\0'. If @size is == 0 the function returns 0.
2793 */
2794
scnprintf(char * buf,size_t size,const char * fmt,...)2795 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2796 {
2797 va_list args;
2798 int i;
2799
2800 va_start(args, fmt);
2801 i = vscnprintf(buf, size, fmt, args);
2802 va_end(args);
2803
2804 return i;
2805 }
2806 EXPORT_SYMBOL(scnprintf);
2807
2808 /**
2809 * vsprintf - Format a string and place it in a buffer
2810 * @buf: The buffer to place the result into
2811 * @fmt: The format string to use
2812 * @args: Arguments for the format string
2813 *
2814 * The function returns the number of characters written
2815 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2816 * buffer overflows.
2817 *
2818 * If you're not already dealing with a va_list consider using sprintf().
2819 *
2820 * See the vsnprintf() documentation for format string extensions over C99.
2821 */
vsprintf(char * buf,const char * fmt,va_list args)2822 int vsprintf(char *buf, const char *fmt, va_list args)
2823 {
2824 return vsnprintf(buf, INT_MAX, fmt, args);
2825 }
2826 EXPORT_SYMBOL(vsprintf);
2827
2828 /**
2829 * sprintf - Format a string and place it in a buffer
2830 * @buf: The buffer to place the result into
2831 * @fmt: The format string to use
2832 * @...: Arguments for the format string
2833 *
2834 * The function returns the number of characters written
2835 * into @buf. Use snprintf() or scnprintf() in order to avoid
2836 * buffer overflows.
2837 *
2838 * See the vsnprintf() documentation for format string extensions over C99.
2839 */
sprintf(char * buf,const char * fmt,...)2840 int sprintf(char *buf, const char *fmt, ...)
2841 {
2842 va_list args;
2843 int i;
2844
2845 va_start(args, fmt);
2846 i = vsnprintf(buf, INT_MAX, fmt, args);
2847 va_end(args);
2848
2849 return i;
2850 }
2851 EXPORT_SYMBOL(sprintf);
2852
2853 #ifdef CONFIG_BINARY_PRINTF
2854 /*
2855 * bprintf service:
2856 * vbin_printf() - VA arguments to binary data
2857 * bstr_printf() - Binary data to text string
2858 */
2859
2860 /**
2861 * vbin_printf - Parse a format string and place args' binary value in a buffer
2862 * @bin_buf: The buffer to place args' binary value
2863 * @size: The size of the buffer(by words(32bits), not characters)
2864 * @fmt: The format string to use
2865 * @args: Arguments for the format string
2866 *
2867 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2868 * is skipped.
2869 *
2870 * The return value is the number of words(32bits) which would be generated for
2871 * the given input.
2872 *
2873 * NOTE:
2874 * If the return value is greater than @size, the resulting bin_buf is NOT
2875 * valid for bstr_printf().
2876 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt,va_list args)2877 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2878 {
2879 struct printf_spec spec = {0};
2880 char *str, *end;
2881 int width;
2882
2883 str = (char *)bin_buf;
2884 end = (char *)(bin_buf + size);
2885
2886 #define save_arg(type) \
2887 ({ \
2888 unsigned long long value; \
2889 if (sizeof(type) == 8) { \
2890 unsigned long long val8; \
2891 str = PTR_ALIGN(str, sizeof(u32)); \
2892 val8 = va_arg(args, unsigned long long); \
2893 if (str + sizeof(type) <= end) { \
2894 *(u32 *)str = *(u32 *)&val8; \
2895 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
2896 } \
2897 value = val8; \
2898 } else { \
2899 unsigned int val4; \
2900 str = PTR_ALIGN(str, sizeof(type)); \
2901 val4 = va_arg(args, int); \
2902 if (str + sizeof(type) <= end) \
2903 *(typeof(type) *)str = (type)(long)val4; \
2904 value = (unsigned long long)val4; \
2905 } \
2906 str += sizeof(type); \
2907 value; \
2908 })
2909
2910 while (*fmt) {
2911 int read = format_decode(fmt, &spec);
2912
2913 fmt += read;
2914
2915 switch (spec.type) {
2916 case FORMAT_TYPE_NONE:
2917 case FORMAT_TYPE_PERCENT_CHAR:
2918 break;
2919 case FORMAT_TYPE_INVALID:
2920 goto out;
2921
2922 case FORMAT_TYPE_WIDTH:
2923 case FORMAT_TYPE_PRECISION:
2924 width = (int)save_arg(int);
2925 /* Pointers may require the width */
2926 if (*fmt == 'p')
2927 set_field_width(&spec, width);
2928 break;
2929
2930 case FORMAT_TYPE_CHAR:
2931 save_arg(char);
2932 break;
2933
2934 case FORMAT_TYPE_STR: {
2935 const char *save_str = va_arg(args, char *);
2936 const char *err_msg;
2937 size_t len;
2938
2939 err_msg = check_pointer_msg(save_str);
2940 if (err_msg)
2941 save_str = err_msg;
2942
2943 len = strlen(save_str) + 1;
2944 if (str + len < end)
2945 memcpy(str, save_str, len);
2946 str += len;
2947 break;
2948 }
2949
2950 case FORMAT_TYPE_PTR:
2951 /* Dereferenced pointers must be done now */
2952 switch (*fmt) {
2953 /* Dereference of functions is still OK */
2954 case 'S':
2955 case 's':
2956 case 'x':
2957 case 'K':
2958 case 'e':
2959 save_arg(void *);
2960 break;
2961 default:
2962 if (!isalnum(*fmt)) {
2963 save_arg(void *);
2964 break;
2965 }
2966 str = pointer(fmt, str, end, va_arg(args, void *),
2967 spec);
2968 if (str + 1 < end)
2969 *str++ = '\0';
2970 else
2971 end[-1] = '\0'; /* Must be nul terminated */
2972 }
2973 /* skip all alphanumeric pointer suffixes */
2974 while (isalnum(*fmt))
2975 fmt++;
2976 break;
2977
2978 default:
2979 switch (spec.type) {
2980
2981 case FORMAT_TYPE_LONG_LONG:
2982 save_arg(long long);
2983 break;
2984 case FORMAT_TYPE_ULONG:
2985 case FORMAT_TYPE_LONG:
2986 save_arg(unsigned long);
2987 break;
2988 case FORMAT_TYPE_SIZE_T:
2989 save_arg(size_t);
2990 break;
2991 case FORMAT_TYPE_PTRDIFF:
2992 save_arg(ptrdiff_t);
2993 break;
2994 case FORMAT_TYPE_UBYTE:
2995 case FORMAT_TYPE_BYTE:
2996 save_arg(char);
2997 break;
2998 case FORMAT_TYPE_USHORT:
2999 case FORMAT_TYPE_SHORT:
3000 save_arg(short);
3001 break;
3002 default:
3003 save_arg(int);
3004 }
3005 }
3006 }
3007
3008 out:
3009 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3010 #undef save_arg
3011 }
3012 EXPORT_SYMBOL_GPL(vbin_printf);
3013
3014 /**
3015 * bstr_printf - Format a string from binary arguments and place it in a buffer
3016 * @buf: The buffer to place the result into
3017 * @size: The size of the buffer, including the trailing null space
3018 * @fmt: The format string to use
3019 * @bin_buf: Binary arguments for the format string
3020 *
3021 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3022 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3023 * a binary buffer that generated by vbin_printf.
3024 *
3025 * The format follows C99 vsnprintf, but has some extensions:
3026 * see vsnprintf comment for details.
3027 *
3028 * The return value is the number of characters which would
3029 * be generated for the given input, excluding the trailing
3030 * '\0', as per ISO C99. If you want to have the exact
3031 * number of characters written into @buf as return value
3032 * (not including the trailing '\0'), use vscnprintf(). If the
3033 * return is greater than or equal to @size, the resulting
3034 * string is truncated.
3035 */
bstr_printf(char * buf,size_t size,const char * fmt,const u32 * bin_buf)3036 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3037 {
3038 struct printf_spec spec = {0};
3039 char *str, *end;
3040 const char *args = (const char *)bin_buf;
3041
3042 if (WARN_ON_ONCE(size > INT_MAX))
3043 return 0;
3044
3045 str = buf;
3046 end = buf + size;
3047
3048 #define get_arg(type) \
3049 ({ \
3050 typeof(type) value; \
3051 if (sizeof(type) == 8) { \
3052 args = PTR_ALIGN(args, sizeof(u32)); \
3053 *(u32 *)&value = *(u32 *)args; \
3054 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3055 } else { \
3056 args = PTR_ALIGN(args, sizeof(type)); \
3057 value = *(typeof(type) *)args; \
3058 } \
3059 args += sizeof(type); \
3060 value; \
3061 })
3062
3063 /* Make sure end is always >= buf */
3064 if (end < buf) {
3065 end = ((void *)-1);
3066 size = end - buf;
3067 }
3068
3069 while (*fmt) {
3070 const char *old_fmt = fmt;
3071 int read = format_decode(fmt, &spec);
3072
3073 fmt += read;
3074
3075 switch (spec.type) {
3076 case FORMAT_TYPE_NONE: {
3077 int copy = read;
3078 if (str < end) {
3079 if (copy > end - str)
3080 copy = end - str;
3081 memcpy(str, old_fmt, copy);
3082 }
3083 str += read;
3084 break;
3085 }
3086
3087 case FORMAT_TYPE_WIDTH:
3088 set_field_width(&spec, get_arg(int));
3089 break;
3090
3091 case FORMAT_TYPE_PRECISION:
3092 set_precision(&spec, get_arg(int));
3093 break;
3094
3095 case FORMAT_TYPE_CHAR: {
3096 char c;
3097
3098 if (!(spec.flags & LEFT)) {
3099 while (--spec.field_width > 0) {
3100 if (str < end)
3101 *str = ' ';
3102 ++str;
3103 }
3104 }
3105 c = (unsigned char) get_arg(char);
3106 if (str < end)
3107 *str = c;
3108 ++str;
3109 while (--spec.field_width > 0) {
3110 if (str < end)
3111 *str = ' ';
3112 ++str;
3113 }
3114 break;
3115 }
3116
3117 case FORMAT_TYPE_STR: {
3118 const char *str_arg = args;
3119 args += strlen(str_arg) + 1;
3120 str = string(str, end, (char *)str_arg, spec);
3121 break;
3122 }
3123
3124 case FORMAT_TYPE_PTR: {
3125 bool process = false;
3126 int copy, len;
3127 /* Non function dereferences were already done */
3128 switch (*fmt) {
3129 case 'S':
3130 case 's':
3131 case 'x':
3132 case 'K':
3133 case 'e':
3134 process = true;
3135 break;
3136 default:
3137 if (!isalnum(*fmt)) {
3138 process = true;
3139 break;
3140 }
3141 /* Pointer dereference was already processed */
3142 if (str < end) {
3143 len = copy = strlen(args);
3144 if (copy > end - str)
3145 copy = end - str;
3146 memcpy(str, args, copy);
3147 str += len;
3148 args += len + 1;
3149 }
3150 }
3151 if (process)
3152 str = pointer(fmt, str, end, get_arg(void *), spec);
3153
3154 while (isalnum(*fmt))
3155 fmt++;
3156 break;
3157 }
3158
3159 case FORMAT_TYPE_PERCENT_CHAR:
3160 if (str < end)
3161 *str = '%';
3162 ++str;
3163 break;
3164
3165 case FORMAT_TYPE_INVALID:
3166 goto out;
3167
3168 default: {
3169 unsigned long long num;
3170
3171 switch (spec.type) {
3172
3173 case FORMAT_TYPE_LONG_LONG:
3174 num = get_arg(long long);
3175 break;
3176 case FORMAT_TYPE_ULONG:
3177 case FORMAT_TYPE_LONG:
3178 num = get_arg(unsigned long);
3179 break;
3180 case FORMAT_TYPE_SIZE_T:
3181 num = get_arg(size_t);
3182 break;
3183 case FORMAT_TYPE_PTRDIFF:
3184 num = get_arg(ptrdiff_t);
3185 break;
3186 case FORMAT_TYPE_UBYTE:
3187 num = get_arg(unsigned char);
3188 break;
3189 case FORMAT_TYPE_BYTE:
3190 num = get_arg(signed char);
3191 break;
3192 case FORMAT_TYPE_USHORT:
3193 num = get_arg(unsigned short);
3194 break;
3195 case FORMAT_TYPE_SHORT:
3196 num = get_arg(short);
3197 break;
3198 case FORMAT_TYPE_UINT:
3199 num = get_arg(unsigned int);
3200 break;
3201 default:
3202 num = get_arg(int);
3203 }
3204
3205 str = number(str, end, num, spec);
3206 } /* default: */
3207 } /* switch(spec.type) */
3208 } /* while(*fmt) */
3209
3210 out:
3211 if (size > 0) {
3212 if (str < end)
3213 *str = '\0';
3214 else
3215 end[-1] = '\0';
3216 }
3217
3218 #undef get_arg
3219
3220 /* the trailing null byte doesn't count towards the total */
3221 return str - buf;
3222 }
3223 EXPORT_SYMBOL_GPL(bstr_printf);
3224
3225 /**
3226 * bprintf - Parse a format string and place args' binary value in a buffer
3227 * @bin_buf: The buffer to place args' binary value
3228 * @size: The size of the buffer(by words(32bits), not characters)
3229 * @fmt: The format string to use
3230 * @...: Arguments for the format string
3231 *
3232 * The function returns the number of words(u32) written
3233 * into @bin_buf.
3234 */
bprintf(u32 * bin_buf,size_t size,const char * fmt,...)3235 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3236 {
3237 va_list args;
3238 int ret;
3239
3240 va_start(args, fmt);
3241 ret = vbin_printf(bin_buf, size, fmt, args);
3242 va_end(args);
3243
3244 return ret;
3245 }
3246 EXPORT_SYMBOL_GPL(bprintf);
3247
3248 #endif /* CONFIG_BINARY_PRINTF */
3249
3250 /**
3251 * vsscanf - Unformat a buffer into a list of arguments
3252 * @buf: input buffer
3253 * @fmt: format of buffer
3254 * @args: arguments
3255 */
vsscanf(const char * buf,const char * fmt,va_list args)3256 int vsscanf(const char *buf, const char *fmt, va_list args)
3257 {
3258 const char *str = buf;
3259 char *next;
3260 char digit;
3261 int num = 0;
3262 u8 qualifier;
3263 unsigned int base;
3264 union {
3265 long long s;
3266 unsigned long long u;
3267 } val;
3268 s16 field_width;
3269 bool is_sign;
3270
3271 while (*fmt) {
3272 /* skip any white space in format */
3273 /* white space in format matchs any amount of
3274 * white space, including none, in the input.
3275 */
3276 if (isspace(*fmt)) {
3277 fmt = skip_spaces(++fmt);
3278 str = skip_spaces(str);
3279 }
3280
3281 /* anything that is not a conversion must match exactly */
3282 if (*fmt != '%' && *fmt) {
3283 if (*fmt++ != *str++)
3284 break;
3285 continue;
3286 }
3287
3288 if (!*fmt)
3289 break;
3290 ++fmt;
3291
3292 /* skip this conversion.
3293 * advance both strings to next white space
3294 */
3295 if (*fmt == '*') {
3296 if (!*str)
3297 break;
3298 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3299 /* '%*[' not yet supported, invalid format */
3300 if (*fmt == '[')
3301 return num;
3302 fmt++;
3303 }
3304 while (!isspace(*str) && *str)
3305 str++;
3306 continue;
3307 }
3308
3309 /* get field width */
3310 field_width = -1;
3311 if (isdigit(*fmt)) {
3312 field_width = skip_atoi(&fmt);
3313 if (field_width <= 0)
3314 break;
3315 }
3316
3317 /* get conversion qualifier */
3318 qualifier = -1;
3319 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3320 *fmt == 'z') {
3321 qualifier = *fmt++;
3322 if (unlikely(qualifier == *fmt)) {
3323 if (qualifier == 'h') {
3324 qualifier = 'H';
3325 fmt++;
3326 } else if (qualifier == 'l') {
3327 qualifier = 'L';
3328 fmt++;
3329 }
3330 }
3331 }
3332
3333 if (!*fmt)
3334 break;
3335
3336 if (*fmt == 'n') {
3337 /* return number of characters read so far */
3338 *va_arg(args, int *) = str - buf;
3339 ++fmt;
3340 continue;
3341 }
3342
3343 if (!*str)
3344 break;
3345
3346 base = 10;
3347 is_sign = false;
3348
3349 switch (*fmt++) {
3350 case 'c':
3351 {
3352 char *s = (char *)va_arg(args, char*);
3353 if (field_width == -1)
3354 field_width = 1;
3355 do {
3356 *s++ = *str++;
3357 } while (--field_width > 0 && *str);
3358 num++;
3359 }
3360 continue;
3361 case 's':
3362 {
3363 char *s = (char *)va_arg(args, char *);
3364 if (field_width == -1)
3365 field_width = SHRT_MAX;
3366 /* first, skip leading white space in buffer */
3367 str = skip_spaces(str);
3368
3369 /* now copy until next white space */
3370 while (*str && !isspace(*str) && field_width--)
3371 *s++ = *str++;
3372 *s = '\0';
3373 num++;
3374 }
3375 continue;
3376 /*
3377 * Warning: This implementation of the '[' conversion specifier
3378 * deviates from its glibc counterpart in the following ways:
3379 * (1) It does NOT support ranges i.e. '-' is NOT a special
3380 * character
3381 * (2) It cannot match the closing bracket ']' itself
3382 * (3) A field width is required
3383 * (4) '%*[' (discard matching input) is currently not supported
3384 *
3385 * Example usage:
3386 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3387 * buf1, buf2, buf3);
3388 * if (ret < 3)
3389 * // etc..
3390 */
3391 case '[':
3392 {
3393 char *s = (char *)va_arg(args, char *);
3394 DECLARE_BITMAP(set, 256) = {0};
3395 unsigned int len = 0;
3396 bool negate = (*fmt == '^');
3397
3398 /* field width is required */
3399 if (field_width == -1)
3400 return num;
3401
3402 if (negate)
3403 ++fmt;
3404
3405 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3406 set_bit((u8)*fmt, set);
3407
3408 /* no ']' or no character set found */
3409 if (!*fmt || !len)
3410 return num;
3411 ++fmt;
3412
3413 if (negate) {
3414 bitmap_complement(set, set, 256);
3415 /* exclude null '\0' byte */
3416 clear_bit(0, set);
3417 }
3418
3419 /* match must be non-empty */
3420 if (!test_bit((u8)*str, set))
3421 return num;
3422
3423 while (test_bit((u8)*str, set) && field_width--)
3424 *s++ = *str++;
3425 *s = '\0';
3426 ++num;
3427 }
3428 continue;
3429 case 'o':
3430 base = 8;
3431 break;
3432 case 'x':
3433 case 'X':
3434 base = 16;
3435 break;
3436 case 'i':
3437 base = 0;
3438 /* fall through */
3439 case 'd':
3440 is_sign = true;
3441 /* fall through */
3442 case 'u':
3443 break;
3444 case '%':
3445 /* looking for '%' in str */
3446 if (*str++ != '%')
3447 return num;
3448 continue;
3449 default:
3450 /* invalid format; stop here */
3451 return num;
3452 }
3453
3454 /* have some sort of integer conversion.
3455 * first, skip white space in buffer.
3456 */
3457 str = skip_spaces(str);
3458
3459 digit = *str;
3460 if (is_sign && digit == '-')
3461 digit = *(str + 1);
3462
3463 if (!digit
3464 || (base == 16 && !isxdigit(digit))
3465 || (base == 10 && !isdigit(digit))
3466 || (base == 8 && (!isdigit(digit) || digit > '7'))
3467 || (base == 0 && !isdigit(digit)))
3468 break;
3469
3470 if (is_sign)
3471 val.s = simple_strntoll(str,
3472 field_width >= 0 ? field_width : INT_MAX,
3473 &next, base);
3474 else
3475 val.u = simple_strntoull(str,
3476 field_width >= 0 ? field_width : INT_MAX,
3477 &next, base);
3478
3479 switch (qualifier) {
3480 case 'H': /* that's 'hh' in format */
3481 if (is_sign)
3482 *va_arg(args, signed char *) = val.s;
3483 else
3484 *va_arg(args, unsigned char *) = val.u;
3485 break;
3486 case 'h':
3487 if (is_sign)
3488 *va_arg(args, short *) = val.s;
3489 else
3490 *va_arg(args, unsigned short *) = val.u;
3491 break;
3492 case 'l':
3493 if (is_sign)
3494 *va_arg(args, long *) = val.s;
3495 else
3496 *va_arg(args, unsigned long *) = val.u;
3497 break;
3498 case 'L':
3499 if (is_sign)
3500 *va_arg(args, long long *) = val.s;
3501 else
3502 *va_arg(args, unsigned long long *) = val.u;
3503 break;
3504 case 'z':
3505 *va_arg(args, size_t *) = val.u;
3506 break;
3507 default:
3508 if (is_sign)
3509 *va_arg(args, int *) = val.s;
3510 else
3511 *va_arg(args, unsigned int *) = val.u;
3512 break;
3513 }
3514 num++;
3515
3516 if (!next)
3517 break;
3518 str = next;
3519 }
3520
3521 return num;
3522 }
3523 EXPORT_SYMBOL(vsscanf);
3524
3525 /**
3526 * sscanf - Unformat a buffer into a list of arguments
3527 * @buf: input buffer
3528 * @fmt: formatting of buffer
3529 * @...: resulting arguments
3530 */
sscanf(const char * buf,const char * fmt,...)3531 int sscanf(const char *buf, const char *fmt, ...)
3532 {
3533 va_list args;
3534 int i;
3535
3536 va_start(args, fmt);
3537 i = vsscanf(buf, fmt, args);
3538 va_end(args);
3539
3540 return i;
3541 }
3542 EXPORT_SYMBOL(sscanf);
3543