1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/lib/vsprintf.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
11 */
12
13 /*
14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17 * - scnprintf and vscnprintf
18 */
19
20 #include <linux/stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/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 #include <asm/unaligned.h>
53
54 #include <linux/string_helpers.h>
55 #include "kstrtox.h"
56
57 /* Disable pointer hashing if requested */
58 bool no_hash_pointers __ro_after_init;
59 EXPORT_SYMBOL_GPL(no_hash_pointers);
60
simple_strntoull(const char * startp,size_t max_chars,char ** endp,unsigned int base)61 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
62 {
63 const char *cp;
64 unsigned long long result = 0ULL;
65 size_t prefix_chars;
66 unsigned int rv;
67
68 cp = _parse_integer_fixup_radix(startp, &base);
69 prefix_chars = cp - startp;
70 if (prefix_chars < max_chars) {
71 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
72 /* FIXME */
73 cp += (rv & ~KSTRTOX_OVERFLOW);
74 } else {
75 /* Field too short for prefix + digit, skip over without converting */
76 cp = startp + max_chars;
77 }
78
79 if (endp)
80 *endp = (char *)cp;
81
82 return result;
83 }
84
85 /**
86 * simple_strtoull - convert a string to an unsigned long long
87 * @cp: The start of the string
88 * @endp: A pointer to the end of the parsed string will be placed here
89 * @base: The number base to use
90 *
91 * This function has caveats. Please use kstrtoull instead.
92 */
93 noinline
simple_strtoull(const char * cp,char ** endp,unsigned int base)94 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
95 {
96 return simple_strntoull(cp, INT_MAX, endp, base);
97 }
98 EXPORT_SYMBOL(simple_strtoull);
99
100 /**
101 * simple_strtoul - convert a string to an unsigned long
102 * @cp: The start of the string
103 * @endp: A pointer to the end of the parsed string will be placed here
104 * @base: The number base to use
105 *
106 * This function has caveats. Please use kstrtoul instead.
107 */
simple_strtoul(const char * cp,char ** endp,unsigned int base)108 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
109 {
110 return simple_strtoull(cp, endp, base);
111 }
112 EXPORT_SYMBOL(simple_strtoul);
113
114 /**
115 * simple_strtol - convert a string to a signed long
116 * @cp: The start of the string
117 * @endp: A pointer to the end of the parsed string will be placed here
118 * @base: The number base to use
119 *
120 * This function has caveats. Please use kstrtol instead.
121 */
simple_strtol(const char * cp,char ** endp,unsigned int base)122 long simple_strtol(const char *cp, char **endp, unsigned int base)
123 {
124 if (*cp == '-')
125 return -simple_strtoul(cp + 1, endp, base);
126
127 return simple_strtoul(cp, endp, base);
128 }
129 EXPORT_SYMBOL(simple_strtol);
130
simple_strntoll(const char * cp,size_t max_chars,char ** endp,unsigned int base)131 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
132 unsigned int base)
133 {
134 /*
135 * simple_strntoull() safely handles receiving max_chars==0 in the
136 * case cp[0] == '-' && max_chars == 1.
137 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
138 * and the content of *cp is irrelevant.
139 */
140 if (*cp == '-' && max_chars > 0)
141 return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
142
143 return simple_strntoull(cp, max_chars, endp, base);
144 }
145
146 /**
147 * simple_strtoll - convert a string to a signed long long
148 * @cp: The start of the string
149 * @endp: A pointer to the end of the parsed string will be placed here
150 * @base: The number base to use
151 *
152 * This function has caveats. Please use kstrtoll instead.
153 */
simple_strtoll(const char * cp,char ** endp,unsigned int base)154 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
155 {
156 return simple_strntoll(cp, INT_MAX, endp, base);
157 }
158 EXPORT_SYMBOL(simple_strtoll);
159
160 static noinline_for_stack
skip_atoi(const char ** s)161 int skip_atoi(const char **s)
162 {
163 int i = 0;
164
165 do {
166 i = i*10 + *((*s)++) - '0';
167 } while (isdigit(**s));
168
169 return i;
170 }
171
172 /*
173 * Decimal conversion is by far the most typical, and is used for
174 * /proc and /sys data. This directly impacts e.g. top performance
175 * with many processes running. We optimize it for speed by emitting
176 * two characters at a time, using a 200 byte lookup table. This
177 * roughly halves the number of multiplications compared to computing
178 * the digits one at a time. Implementation strongly inspired by the
179 * previous version, which in turn used ideas described at
180 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
181 * from the author, Douglas W. Jones).
182 *
183 * It turns out there is precisely one 26 bit fixed-point
184 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
185 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
186 * range happens to be somewhat larger (x <= 1073741898), but that's
187 * irrelevant for our purpose.
188 *
189 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
190 * need a 32x32->64 bit multiply, so we simply use the same constant.
191 *
192 * For dividing a number in the range [100, 10^4-1] by 100, there are
193 * several options. The simplest is (x * 0x147b) >> 19, which is valid
194 * for all x <= 43698.
195 */
196
197 static const u16 decpair[100] = {
198 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
199 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
200 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
201 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
202 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
203 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
204 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
205 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
206 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
207 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
208 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
209 #undef _
210 };
211
212 /*
213 * This will print a single '0' even if r == 0, since we would
214 * immediately jump to out_r where two 0s would be written but only
215 * one of them accounted for in buf. This is needed by ip4_string
216 * below. All other callers pass a non-zero value of r.
217 */
218 static noinline_for_stack
put_dec_trunc8(char * buf,unsigned r)219 char *put_dec_trunc8(char *buf, unsigned r)
220 {
221 unsigned q;
222
223 /* 1 <= r < 10^8 */
224 if (r < 100)
225 goto out_r;
226
227 /* 100 <= r < 10^8 */
228 q = (r * (u64)0x28f5c29) >> 32;
229 *((u16 *)buf) = decpair[r - 100*q];
230 buf += 2;
231
232 /* 1 <= q < 10^6 */
233 if (q < 100)
234 goto out_q;
235
236 /* 100 <= q < 10^6 */
237 r = (q * (u64)0x28f5c29) >> 32;
238 *((u16 *)buf) = decpair[q - 100*r];
239 buf += 2;
240
241 /* 1 <= r < 10^4 */
242 if (r < 100)
243 goto out_r;
244
245 /* 100 <= r < 10^4 */
246 q = (r * 0x147b) >> 19;
247 *((u16 *)buf) = decpair[r - 100*q];
248 buf += 2;
249 out_q:
250 /* 1 <= q < 100 */
251 r = q;
252 out_r:
253 /* 1 <= r < 100 */
254 *((u16 *)buf) = decpair[r];
255 buf += r < 10 ? 1 : 2;
256 return buf;
257 }
258
259 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
260 static noinline_for_stack
put_dec_full8(char * buf,unsigned r)261 char *put_dec_full8(char *buf, unsigned r)
262 {
263 unsigned q;
264
265 /* 0 <= r < 10^8 */
266 q = (r * (u64)0x28f5c29) >> 32;
267 *((u16 *)buf) = decpair[r - 100*q];
268 buf += 2;
269
270 /* 0 <= q < 10^6 */
271 r = (q * (u64)0x28f5c29) >> 32;
272 *((u16 *)buf) = decpair[q - 100*r];
273 buf += 2;
274
275 /* 0 <= r < 10^4 */
276 q = (r * 0x147b) >> 19;
277 *((u16 *)buf) = decpair[r - 100*q];
278 buf += 2;
279
280 /* 0 <= q < 100 */
281 *((u16 *)buf) = decpair[q];
282 buf += 2;
283 return buf;
284 }
285
286 static noinline_for_stack
put_dec(char * buf,unsigned long long n)287 char *put_dec(char *buf, unsigned long long n)
288 {
289 if (n >= 100*1000*1000)
290 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
291 /* 1 <= n <= 1.6e11 */
292 if (n >= 100*1000*1000)
293 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
294 /* 1 <= n < 1e8 */
295 return put_dec_trunc8(buf, n);
296 }
297
298 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
299
300 static void
put_dec_full4(char * buf,unsigned r)301 put_dec_full4(char *buf, unsigned r)
302 {
303 unsigned q;
304
305 /* 0 <= r < 10^4 */
306 q = (r * 0x147b) >> 19;
307 *((u16 *)buf) = decpair[r - 100*q];
308 buf += 2;
309 /* 0 <= q < 100 */
310 *((u16 *)buf) = decpair[q];
311 }
312
313 /*
314 * Call put_dec_full4 on x % 10000, return x / 10000.
315 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
316 * holds for all x < 1,128,869,999. The largest value this
317 * helper will ever be asked to convert is 1,125,520,955.
318 * (second call in the put_dec code, assuming n is all-ones).
319 */
320 static noinline_for_stack
put_dec_helper4(char * buf,unsigned x)321 unsigned put_dec_helper4(char *buf, unsigned x)
322 {
323 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
324
325 put_dec_full4(buf, x - q * 10000);
326 return q;
327 }
328
329 /* Based on code by Douglas W. Jones found at
330 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
331 * (with permission from the author).
332 * Performs no 64-bit division and hence should be fast on 32-bit machines.
333 */
334 static
put_dec(char * buf,unsigned long long n)335 char *put_dec(char *buf, unsigned long long n)
336 {
337 uint32_t d3, d2, d1, q, h;
338
339 if (n < 100*1000*1000)
340 return put_dec_trunc8(buf, n);
341
342 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
343 h = (n >> 32);
344 d2 = (h ) & 0xffff;
345 d3 = (h >> 16); /* implicit "& 0xffff" */
346
347 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
348 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
349 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
350 q = put_dec_helper4(buf, q);
351
352 q += 7671 * d3 + 9496 * d2 + 6 * d1;
353 q = put_dec_helper4(buf+4, q);
354
355 q += 4749 * d3 + 42 * d2;
356 q = put_dec_helper4(buf+8, q);
357
358 q += 281 * d3;
359 buf += 12;
360 if (q)
361 buf = put_dec_trunc8(buf, q);
362 else while (buf[-1] == '0')
363 --buf;
364
365 return buf;
366 }
367
368 #endif
369
370 /*
371 * Convert passed number to decimal string.
372 * Returns the length of string. On buffer overflow, returns 0.
373 *
374 * If speed is not important, use snprintf(). It's easy to read the code.
375 */
num_to_str(char * buf,int size,unsigned long long num,unsigned int width)376 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
377 {
378 /* put_dec requires 2-byte alignment of the buffer. */
379 char tmp[sizeof(num) * 3] __aligned(2);
380 int idx, len;
381
382 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
383 if (num <= 9) {
384 tmp[0] = '0' + num;
385 len = 1;
386 } else {
387 len = put_dec(tmp, num) - tmp;
388 }
389
390 if (len > size || width > size)
391 return 0;
392
393 if (width > len) {
394 width = width - len;
395 for (idx = 0; idx < width; idx++)
396 buf[idx] = ' ';
397 } else {
398 width = 0;
399 }
400
401 for (idx = 0; idx < len; ++idx)
402 buf[idx + width] = tmp[len - idx - 1];
403
404 return len + width;
405 }
406
407 #define SIGN 1 /* unsigned/signed, must be 1 */
408 #define LEFT 2 /* left justified */
409 #define PLUS 4 /* show plus */
410 #define SPACE 8 /* space if plus */
411 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
412 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
413 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
414
415 static_assert(ZEROPAD == ('0' - ' '));
416 static_assert(SMALL == ' ');
417
418 enum format_type {
419 FORMAT_TYPE_NONE, /* Just a string part */
420 FORMAT_TYPE_WIDTH,
421 FORMAT_TYPE_PRECISION,
422 FORMAT_TYPE_CHAR,
423 FORMAT_TYPE_STR,
424 FORMAT_TYPE_PTR,
425 FORMAT_TYPE_PERCENT_CHAR,
426 FORMAT_TYPE_INVALID,
427 FORMAT_TYPE_LONG_LONG,
428 FORMAT_TYPE_ULONG,
429 FORMAT_TYPE_LONG,
430 FORMAT_TYPE_UBYTE,
431 FORMAT_TYPE_BYTE,
432 FORMAT_TYPE_USHORT,
433 FORMAT_TYPE_SHORT,
434 FORMAT_TYPE_UINT,
435 FORMAT_TYPE_INT,
436 FORMAT_TYPE_SIZE_T,
437 FORMAT_TYPE_PTRDIFF
438 };
439
440 struct printf_spec {
441 unsigned int type:8; /* format_type enum */
442 signed int field_width:24; /* width of output field */
443 unsigned int flags:8; /* flags to number() */
444 unsigned int base:8; /* number base, 8, 10 or 16 only */
445 signed int precision:16; /* # of digits/chars */
446 } __packed;
447 static_assert(sizeof(struct printf_spec) == 8);
448
449 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
450 #define PRECISION_MAX ((1 << 15) - 1)
451
452 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)453 char *number(char *buf, char *end, unsigned long long num,
454 struct printf_spec spec)
455 {
456 /* put_dec requires 2-byte alignment of the buffer. */
457 char tmp[3 * sizeof(num)] __aligned(2);
458 char sign;
459 char locase;
460 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
461 int i;
462 bool is_zero = num == 0LL;
463 int field_width = spec.field_width;
464 int precision = spec.precision;
465
466 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
467 * produces same digits or (maybe lowercased) letters */
468 locase = (spec.flags & SMALL);
469 if (spec.flags & LEFT)
470 spec.flags &= ~ZEROPAD;
471 sign = 0;
472 if (spec.flags & SIGN) {
473 if ((signed long long)num < 0) {
474 sign = '-';
475 num = -(signed long long)num;
476 field_width--;
477 } else if (spec.flags & PLUS) {
478 sign = '+';
479 field_width--;
480 } else if (spec.flags & SPACE) {
481 sign = ' ';
482 field_width--;
483 }
484 }
485 if (need_pfx) {
486 if (spec.base == 16)
487 field_width -= 2;
488 else if (!is_zero)
489 field_width--;
490 }
491
492 /* generate full string in tmp[], in reverse order */
493 i = 0;
494 if (num < spec.base)
495 tmp[i++] = hex_asc_upper[num] | locase;
496 else if (spec.base != 10) { /* 8 or 16 */
497 int mask = spec.base - 1;
498 int shift = 3;
499
500 if (spec.base == 16)
501 shift = 4;
502 do {
503 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
504 num >>= shift;
505 } while (num);
506 } else { /* base 10 */
507 i = put_dec(tmp, num) - tmp;
508 }
509
510 /* printing 100 using %2d gives "100", not "00" */
511 if (i > precision)
512 precision = i;
513 /* leading space padding */
514 field_width -= precision;
515 if (!(spec.flags & (ZEROPAD | LEFT))) {
516 while (--field_width >= 0) {
517 if (buf < end)
518 *buf = ' ';
519 ++buf;
520 }
521 }
522 /* sign */
523 if (sign) {
524 if (buf < end)
525 *buf = sign;
526 ++buf;
527 }
528 /* "0x" / "0" prefix */
529 if (need_pfx) {
530 if (spec.base == 16 || !is_zero) {
531 if (buf < end)
532 *buf = '0';
533 ++buf;
534 }
535 if (spec.base == 16) {
536 if (buf < end)
537 *buf = ('X' | locase);
538 ++buf;
539 }
540 }
541 /* zero or space padding */
542 if (!(spec.flags & LEFT)) {
543 char c = ' ' + (spec.flags & ZEROPAD);
544
545 while (--field_width >= 0) {
546 if (buf < end)
547 *buf = c;
548 ++buf;
549 }
550 }
551 /* hmm even more zero padding? */
552 while (i <= --precision) {
553 if (buf < end)
554 *buf = '0';
555 ++buf;
556 }
557 /* actual digits of result */
558 while (--i >= 0) {
559 if (buf < end)
560 *buf = tmp[i];
561 ++buf;
562 }
563 /* trailing space padding */
564 while (--field_width >= 0) {
565 if (buf < end)
566 *buf = ' ';
567 ++buf;
568 }
569
570 return buf;
571 }
572
573 static noinline_for_stack
special_hex_number(char * buf,char * end,unsigned long long num,int size)574 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
575 {
576 struct printf_spec spec;
577
578 spec.type = FORMAT_TYPE_PTR;
579 spec.field_width = 2 + 2 * size; /* 0x + hex */
580 spec.flags = SPECIAL | SMALL | ZEROPAD;
581 spec.base = 16;
582 spec.precision = -1;
583
584 return number(buf, end, num, spec);
585 }
586
move_right(char * buf,char * end,unsigned len,unsigned spaces)587 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
588 {
589 size_t size;
590 if (buf >= end) /* nowhere to put anything */
591 return;
592 size = end - buf;
593 if (size <= spaces) {
594 memset(buf, ' ', size);
595 return;
596 }
597 if (len) {
598 if (len > size - spaces)
599 len = size - spaces;
600 memmove(buf + spaces, buf, len);
601 }
602 memset(buf, ' ', spaces);
603 }
604
605 /*
606 * Handle field width padding for a string.
607 * @buf: current buffer position
608 * @n: length of string
609 * @end: end of output buffer
610 * @spec: for field width and flags
611 * Returns: new buffer position after padding.
612 */
613 static noinline_for_stack
widen_string(char * buf,int n,char * end,struct printf_spec spec)614 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
615 {
616 unsigned spaces;
617
618 if (likely(n >= spec.field_width))
619 return buf;
620 /* we want to pad the sucker */
621 spaces = spec.field_width - n;
622 if (!(spec.flags & LEFT)) {
623 move_right(buf - n, end, n, spaces);
624 return buf + spaces;
625 }
626 while (spaces--) {
627 if (buf < end)
628 *buf = ' ';
629 ++buf;
630 }
631 return buf;
632 }
633
634 /* Handle string from a well known address. */
string_nocheck(char * buf,char * end,const char * s,struct printf_spec spec)635 static char *string_nocheck(char *buf, char *end, const char *s,
636 struct printf_spec spec)
637 {
638 int len = 0;
639 int lim = spec.precision;
640
641 while (lim--) {
642 char c = *s++;
643 if (!c)
644 break;
645 if (buf < end)
646 *buf = c;
647 ++buf;
648 ++len;
649 }
650 return widen_string(buf, len, end, spec);
651 }
652
err_ptr(char * buf,char * end,void * ptr,struct printf_spec spec)653 static char *err_ptr(char *buf, char *end, void *ptr,
654 struct printf_spec spec)
655 {
656 int err = PTR_ERR(ptr);
657 const char *sym = errname(err);
658
659 if (sym)
660 return string_nocheck(buf, end, sym, spec);
661
662 /*
663 * Somebody passed ERR_PTR(-1234) or some other non-existing
664 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
665 * printing it as its decimal representation.
666 */
667 spec.flags |= SIGN;
668 spec.base = 10;
669 return number(buf, end, err, spec);
670 }
671
672 /* Be careful: error messages must fit into the given buffer. */
error_string(char * buf,char * end,const char * s,struct printf_spec spec)673 static char *error_string(char *buf, char *end, const char *s,
674 struct printf_spec spec)
675 {
676 /*
677 * Hard limit to avoid a completely insane messages. It actually
678 * works pretty well because most error messages are in
679 * the many pointer format modifiers.
680 */
681 if (spec.precision == -1)
682 spec.precision = 2 * sizeof(void *);
683
684 return string_nocheck(buf, end, s, spec);
685 }
686
687 /*
688 * Do not call any complex external code here. Nested printk()/vsprintf()
689 * might cause infinite loops. Failures might break printk() and would
690 * be hard to debug.
691 */
check_pointer_msg(const void * ptr)692 static const char *check_pointer_msg(const void *ptr)
693 {
694 if (!ptr)
695 return "(null)";
696
697 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
698 return "(efault)";
699
700 return NULL;
701 }
702
check_pointer(char ** buf,char * end,const void * ptr,struct printf_spec spec)703 static int check_pointer(char **buf, char *end, const void *ptr,
704 struct printf_spec spec)
705 {
706 const char *err_msg;
707
708 err_msg = check_pointer_msg(ptr);
709 if (err_msg) {
710 *buf = error_string(*buf, end, err_msg, spec);
711 return -EFAULT;
712 }
713
714 return 0;
715 }
716
717 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)718 char *string(char *buf, char *end, const char *s,
719 struct printf_spec spec)
720 {
721 if (check_pointer(&buf, end, s, spec))
722 return buf;
723
724 return string_nocheck(buf, end, s, spec);
725 }
726
pointer_string(char * buf,char * end,const void * ptr,struct printf_spec spec)727 static char *pointer_string(char *buf, char *end,
728 const void *ptr,
729 struct printf_spec spec)
730 {
731 spec.base = 16;
732 spec.flags |= SMALL;
733 if (spec.field_width == -1) {
734 spec.field_width = 2 * sizeof(ptr);
735 spec.flags |= ZEROPAD;
736 }
737
738 return number(buf, end, (unsigned long int)ptr, spec);
739 }
740
741 /* Make pointers available for printing early in the boot sequence. */
742 static int debug_boot_weak_hash __ro_after_init;
743
debug_boot_weak_hash_enable(char * str)744 static int __init debug_boot_weak_hash_enable(char *str)
745 {
746 debug_boot_weak_hash = 1;
747 pr_info("debug_boot_weak_hash enabled\n");
748 return 0;
749 }
750 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
751
752 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
753 static siphash_key_t ptr_key __read_mostly;
754
enable_ptr_key_workfn(struct work_struct * work)755 static void enable_ptr_key_workfn(struct work_struct *work)
756 {
757 get_random_bytes(&ptr_key, sizeof(ptr_key));
758 /* Needs to run from preemptible context */
759 static_branch_disable(¬_filled_random_ptr_key);
760 }
761
762 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
763
fill_random_ptr_key(struct notifier_block * nb,unsigned long action,void * data)764 static int fill_random_ptr_key(struct notifier_block *nb,
765 unsigned long action, void *data)
766 {
767 /* This may be in an interrupt handler. */
768 queue_work(system_unbound_wq, &enable_ptr_key_work);
769 return 0;
770 }
771
772 static struct notifier_block random_ready = {
773 .notifier_call = fill_random_ptr_key
774 };
775
initialize_ptr_random(void)776 static int __init initialize_ptr_random(void)
777 {
778 int key_size = sizeof(ptr_key);
779 int ret;
780
781 /* Use hw RNG if available. */
782 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
783 static_branch_disable(¬_filled_random_ptr_key);
784 return 0;
785 }
786
787 ret = register_random_ready_notifier(&random_ready);
788 if (!ret) {
789 return 0;
790 } else if (ret == -EALREADY) {
791 /* This is in preemptible context */
792 enable_ptr_key_workfn(&enable_ptr_key_work);
793 return 0;
794 }
795
796 return ret;
797 }
798 early_initcall(initialize_ptr_random);
799
800 /* Maps a pointer to a 32 bit unique identifier. */
__ptr_to_hashval(const void * ptr,unsigned long * hashval_out)801 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
802 {
803 unsigned long hashval;
804
805 if (static_branch_unlikely(¬_filled_random_ptr_key))
806 return -EAGAIN;
807
808 #ifdef CONFIG_64BIT
809 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
810 /*
811 * Mask off the first 32 bits, this makes explicit that we have
812 * modified the address (and 32 bits is plenty for a unique ID).
813 */
814 hashval = hashval & 0xffffffff;
815 #else
816 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
817 #endif
818 *hashval_out = hashval;
819 return 0;
820 }
821
ptr_to_hashval(const void * ptr,unsigned long * hashval_out)822 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
823 {
824 return __ptr_to_hashval(ptr, hashval_out);
825 }
826
ptr_to_id(char * buf,char * end,const void * ptr,struct printf_spec spec)827 static char *ptr_to_id(char *buf, char *end, const void *ptr,
828 struct printf_spec spec)
829 {
830 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
831 unsigned long hashval;
832 int ret;
833
834 /*
835 * Print the real pointer value for NULL and error pointers,
836 * as they are not actual addresses.
837 */
838 if (IS_ERR_OR_NULL(ptr))
839 return pointer_string(buf, end, ptr, spec);
840
841 /* When debugging early boot use non-cryptographically secure hash. */
842 if (unlikely(debug_boot_weak_hash)) {
843 hashval = hash_long((unsigned long)ptr, 32);
844 return pointer_string(buf, end, (const void *)hashval, spec);
845 }
846
847 ret = __ptr_to_hashval(ptr, &hashval);
848 if (ret) {
849 spec.field_width = 2 * sizeof(ptr);
850 /* string length must be less than default_width */
851 return error_string(buf, end, str, spec);
852 }
853
854 return pointer_string(buf, end, (const void *)hashval, spec);
855 }
856
default_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)857 static char *default_pointer(char *buf, char *end, const void *ptr,
858 struct printf_spec spec)
859 {
860 /*
861 * default is to _not_ leak addresses, so hash before printing,
862 * unless no_hash_pointers is specified on the command line.
863 */
864 if (unlikely(no_hash_pointers))
865 return pointer_string(buf, end, ptr, spec);
866
867 return ptr_to_id(buf, end, ptr, spec);
868 }
869
870 int kptr_restrict __read_mostly;
871
872 static noinline_for_stack
restricted_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)873 char *restricted_pointer(char *buf, char *end, const void *ptr,
874 struct printf_spec spec)
875 {
876 switch (kptr_restrict) {
877 case 0:
878 /* Handle as %p, hash and do _not_ leak addresses. */
879 return default_pointer(buf, end, ptr, spec);
880 case 1: {
881 const struct cred *cred;
882
883 /*
884 * kptr_restrict==1 cannot be used in IRQ context
885 * because its test for CAP_SYSLOG would be meaningless.
886 */
887 if (in_irq() || in_serving_softirq() || in_nmi()) {
888 if (spec.field_width == -1)
889 spec.field_width = 2 * sizeof(ptr);
890 return error_string(buf, end, "pK-error", spec);
891 }
892
893 /*
894 * Only print the real pointer value if the current
895 * process has CAP_SYSLOG and is running with the
896 * same credentials it started with. This is because
897 * access to files is checked at open() time, but %pK
898 * checks permission at read() time. We don't want to
899 * leak pointer values if a binary opens a file using
900 * %pK and then elevates privileges before reading it.
901 */
902 cred = current_cred();
903 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
904 !uid_eq(cred->euid, cred->uid) ||
905 !gid_eq(cred->egid, cred->gid))
906 ptr = NULL;
907 break;
908 }
909 case 2:
910 default:
911 /* Always print 0's for %pK */
912 ptr = NULL;
913 break;
914 }
915
916 return pointer_string(buf, end, ptr, spec);
917 }
918
919 static noinline_for_stack
dentry_name(char * buf,char * end,const struct dentry * d,struct printf_spec spec,const char * fmt)920 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
921 const char *fmt)
922 {
923 const char *array[4], *s;
924 const struct dentry *p;
925 int depth;
926 int i, n;
927
928 switch (fmt[1]) {
929 case '2': case '3': case '4':
930 depth = fmt[1] - '0';
931 break;
932 default:
933 depth = 1;
934 }
935
936 rcu_read_lock();
937 for (i = 0; i < depth; i++, d = p) {
938 if (check_pointer(&buf, end, d, spec)) {
939 rcu_read_unlock();
940 return buf;
941 }
942
943 p = READ_ONCE(d->d_parent);
944 array[i] = READ_ONCE(d->d_name.name);
945 if (p == d) {
946 if (i)
947 array[i] = "";
948 i++;
949 break;
950 }
951 }
952 s = array[--i];
953 for (n = 0; n != spec.precision; n++, buf++) {
954 char c = *s++;
955 if (!c) {
956 if (!i)
957 break;
958 c = '/';
959 s = array[--i];
960 }
961 if (buf < end)
962 *buf = c;
963 }
964 rcu_read_unlock();
965 return widen_string(buf, n, end, spec);
966 }
967
968 static noinline_for_stack
file_dentry_name(char * buf,char * end,const struct file * f,struct printf_spec spec,const char * fmt)969 char *file_dentry_name(char *buf, char *end, const struct file *f,
970 struct printf_spec spec, const char *fmt)
971 {
972 if (check_pointer(&buf, end, f, spec))
973 return buf;
974
975 return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
976 }
977 #ifdef CONFIG_BLOCK
978 static noinline_for_stack
bdev_name(char * buf,char * end,struct block_device * bdev,struct printf_spec spec,const char * fmt)979 char *bdev_name(char *buf, char *end, struct block_device *bdev,
980 struct printf_spec spec, const char *fmt)
981 {
982 struct gendisk *hd;
983
984 if (check_pointer(&buf, end, bdev, spec))
985 return buf;
986
987 hd = bdev->bd_disk;
988 buf = string(buf, end, hd->disk_name, spec);
989 if (bdev->bd_partno) {
990 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
991 if (buf < end)
992 *buf = 'p';
993 buf++;
994 }
995 buf = number(buf, end, bdev->bd_partno, spec);
996 }
997 return buf;
998 }
999 #endif
1000
1001 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)1002 char *symbol_string(char *buf, char *end, void *ptr,
1003 struct printf_spec spec, const char *fmt)
1004 {
1005 unsigned long value;
1006 #ifdef CONFIG_KALLSYMS
1007 char sym[KSYM_SYMBOL_LEN];
1008 #endif
1009
1010 if (fmt[1] == 'R')
1011 ptr = __builtin_extract_return_addr(ptr);
1012 value = (unsigned long)ptr;
1013
1014 #ifdef CONFIG_KALLSYMS
1015 if (*fmt == 'B' && fmt[1] == 'b')
1016 sprint_backtrace_build_id(sym, value);
1017 else if (*fmt == 'B')
1018 sprint_backtrace(sym, value);
1019 else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
1020 sprint_symbol_build_id(sym, value);
1021 else if (*fmt != 's')
1022 sprint_symbol(sym, value);
1023 else
1024 sprint_symbol_no_offset(sym, value);
1025
1026 return string_nocheck(buf, end, sym, spec);
1027 #else
1028 return special_hex_number(buf, end, value, sizeof(void *));
1029 #endif
1030 }
1031
1032 static const struct printf_spec default_str_spec = {
1033 .field_width = -1,
1034 .precision = -1,
1035 };
1036
1037 static const struct printf_spec default_flag_spec = {
1038 .base = 16,
1039 .precision = -1,
1040 .flags = SPECIAL | SMALL,
1041 };
1042
1043 static const struct printf_spec default_dec_spec = {
1044 .base = 10,
1045 .precision = -1,
1046 };
1047
1048 static const struct printf_spec default_dec02_spec = {
1049 .base = 10,
1050 .field_width = 2,
1051 .precision = -1,
1052 .flags = ZEROPAD,
1053 };
1054
1055 static const struct printf_spec default_dec04_spec = {
1056 .base = 10,
1057 .field_width = 4,
1058 .precision = -1,
1059 .flags = ZEROPAD,
1060 };
1061
1062 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)1063 char *resource_string(char *buf, char *end, struct resource *res,
1064 struct printf_spec spec, const char *fmt)
1065 {
1066 #ifndef IO_RSRC_PRINTK_SIZE
1067 #define IO_RSRC_PRINTK_SIZE 6
1068 #endif
1069
1070 #ifndef MEM_RSRC_PRINTK_SIZE
1071 #define MEM_RSRC_PRINTK_SIZE 10
1072 #endif
1073 static const struct printf_spec io_spec = {
1074 .base = 16,
1075 .field_width = IO_RSRC_PRINTK_SIZE,
1076 .precision = -1,
1077 .flags = SPECIAL | SMALL | ZEROPAD,
1078 };
1079 static const struct printf_spec mem_spec = {
1080 .base = 16,
1081 .field_width = MEM_RSRC_PRINTK_SIZE,
1082 .precision = -1,
1083 .flags = SPECIAL | SMALL | ZEROPAD,
1084 };
1085 static const struct printf_spec bus_spec = {
1086 .base = 16,
1087 .field_width = 2,
1088 .precision = -1,
1089 .flags = SMALL | ZEROPAD,
1090 };
1091 static const struct printf_spec str_spec = {
1092 .field_width = -1,
1093 .precision = 10,
1094 .flags = LEFT,
1095 };
1096
1097 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1098 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1099 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1100 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1101 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1102 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1103 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1104 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1105
1106 char *p = sym, *pend = sym + sizeof(sym);
1107 int decode = (fmt[0] == 'R') ? 1 : 0;
1108 const struct printf_spec *specp;
1109
1110 if (check_pointer(&buf, end, res, spec))
1111 return buf;
1112
1113 *p++ = '[';
1114 if (res->flags & IORESOURCE_IO) {
1115 p = string_nocheck(p, pend, "io ", str_spec);
1116 specp = &io_spec;
1117 } else if (res->flags & IORESOURCE_MEM) {
1118 p = string_nocheck(p, pend, "mem ", str_spec);
1119 specp = &mem_spec;
1120 } else if (res->flags & IORESOURCE_IRQ) {
1121 p = string_nocheck(p, pend, "irq ", str_spec);
1122 specp = &default_dec_spec;
1123 } else if (res->flags & IORESOURCE_DMA) {
1124 p = string_nocheck(p, pend, "dma ", str_spec);
1125 specp = &default_dec_spec;
1126 } else if (res->flags & IORESOURCE_BUS) {
1127 p = string_nocheck(p, pend, "bus ", str_spec);
1128 specp = &bus_spec;
1129 } else {
1130 p = string_nocheck(p, pend, "??? ", str_spec);
1131 specp = &mem_spec;
1132 decode = 0;
1133 }
1134 if (decode && res->flags & IORESOURCE_UNSET) {
1135 p = string_nocheck(p, pend, "size ", str_spec);
1136 p = number(p, pend, resource_size(res), *specp);
1137 } else {
1138 p = number(p, pend, res->start, *specp);
1139 if (res->start != res->end) {
1140 *p++ = '-';
1141 p = number(p, pend, res->end, *specp);
1142 }
1143 }
1144 if (decode) {
1145 if (res->flags & IORESOURCE_MEM_64)
1146 p = string_nocheck(p, pend, " 64bit", str_spec);
1147 if (res->flags & IORESOURCE_PREFETCH)
1148 p = string_nocheck(p, pend, " pref", str_spec);
1149 if (res->flags & IORESOURCE_WINDOW)
1150 p = string_nocheck(p, pend, " window", str_spec);
1151 if (res->flags & IORESOURCE_DISABLED)
1152 p = string_nocheck(p, pend, " disabled", str_spec);
1153 } else {
1154 p = string_nocheck(p, pend, " flags ", str_spec);
1155 p = number(p, pend, res->flags, default_flag_spec);
1156 }
1157 *p++ = ']';
1158 *p = '\0';
1159
1160 return string_nocheck(buf, end, sym, spec);
1161 }
1162
1163 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1164 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1165 const char *fmt)
1166 {
1167 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1168 negative value, fallback to the default */
1169 char separator;
1170
1171 if (spec.field_width == 0)
1172 /* nothing to print */
1173 return buf;
1174
1175 if (check_pointer(&buf, end, addr, spec))
1176 return buf;
1177
1178 switch (fmt[1]) {
1179 case 'C':
1180 separator = ':';
1181 break;
1182 case 'D':
1183 separator = '-';
1184 break;
1185 case 'N':
1186 separator = 0;
1187 break;
1188 default:
1189 separator = ' ';
1190 break;
1191 }
1192
1193 if (spec.field_width > 0)
1194 len = min_t(int, spec.field_width, 64);
1195
1196 for (i = 0; i < len; ++i) {
1197 if (buf < end)
1198 *buf = hex_asc_hi(addr[i]);
1199 ++buf;
1200 if (buf < end)
1201 *buf = hex_asc_lo(addr[i]);
1202 ++buf;
1203
1204 if (separator && i != len - 1) {
1205 if (buf < end)
1206 *buf = separator;
1207 ++buf;
1208 }
1209 }
1210
1211 return buf;
1212 }
1213
1214 static noinline_for_stack
bitmap_string(char * buf,char * end,unsigned long * bitmap,struct printf_spec spec,const char * fmt)1215 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1216 struct printf_spec spec, const char *fmt)
1217 {
1218 const int CHUNKSZ = 32;
1219 int nr_bits = max_t(int, spec.field_width, 0);
1220 int i, chunksz;
1221 bool first = true;
1222
1223 if (check_pointer(&buf, end, bitmap, spec))
1224 return buf;
1225
1226 /* reused to print numbers */
1227 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1228
1229 chunksz = nr_bits & (CHUNKSZ - 1);
1230 if (chunksz == 0)
1231 chunksz = CHUNKSZ;
1232
1233 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1234 for (; i >= 0; i -= CHUNKSZ) {
1235 u32 chunkmask, val;
1236 int word, bit;
1237
1238 chunkmask = ((1ULL << chunksz) - 1);
1239 word = i / BITS_PER_LONG;
1240 bit = i % BITS_PER_LONG;
1241 val = (bitmap[word] >> bit) & chunkmask;
1242
1243 if (!first) {
1244 if (buf < end)
1245 *buf = ',';
1246 buf++;
1247 }
1248 first = false;
1249
1250 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1251 buf = number(buf, end, val, spec);
1252
1253 chunksz = CHUNKSZ;
1254 }
1255 return buf;
1256 }
1257
1258 static noinline_for_stack
bitmap_list_string(char * buf,char * end,unsigned long * bitmap,struct printf_spec spec,const char * fmt)1259 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1260 struct printf_spec spec, const char *fmt)
1261 {
1262 int nr_bits = max_t(int, spec.field_width, 0);
1263 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1264 int cur, rbot, rtop;
1265 bool first = true;
1266
1267 if (check_pointer(&buf, end, bitmap, spec))
1268 return buf;
1269
1270 rbot = cur = find_first_bit(bitmap, nr_bits);
1271 while (cur < nr_bits) {
1272 rtop = cur;
1273 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1274 if (cur < nr_bits && cur <= rtop + 1)
1275 continue;
1276
1277 if (!first) {
1278 if (buf < end)
1279 *buf = ',';
1280 buf++;
1281 }
1282 first = false;
1283
1284 buf = number(buf, end, rbot, default_dec_spec);
1285 if (rbot < rtop) {
1286 if (buf < end)
1287 *buf = '-';
1288 buf++;
1289
1290 buf = number(buf, end, rtop, default_dec_spec);
1291 }
1292
1293 rbot = cur;
1294 }
1295 return buf;
1296 }
1297
1298 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1299 char *mac_address_string(char *buf, char *end, u8 *addr,
1300 struct printf_spec spec, const char *fmt)
1301 {
1302 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1303 char *p = mac_addr;
1304 int i;
1305 char separator;
1306 bool reversed = false;
1307
1308 if (check_pointer(&buf, end, addr, spec))
1309 return buf;
1310
1311 switch (fmt[1]) {
1312 case 'F':
1313 separator = '-';
1314 break;
1315
1316 case 'R':
1317 reversed = true;
1318 fallthrough;
1319
1320 default:
1321 separator = ':';
1322 break;
1323 }
1324
1325 for (i = 0; i < 6; i++) {
1326 if (reversed)
1327 p = hex_byte_pack(p, addr[5 - i]);
1328 else
1329 p = hex_byte_pack(p, addr[i]);
1330
1331 if (fmt[0] == 'M' && i != 5)
1332 *p++ = separator;
1333 }
1334 *p = '\0';
1335
1336 return string_nocheck(buf, end, mac_addr, spec);
1337 }
1338
1339 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)1340 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1341 {
1342 int i;
1343 bool leading_zeros = (fmt[0] == 'i');
1344 int index;
1345 int step;
1346
1347 switch (fmt[2]) {
1348 case 'h':
1349 #ifdef __BIG_ENDIAN
1350 index = 0;
1351 step = 1;
1352 #else
1353 index = 3;
1354 step = -1;
1355 #endif
1356 break;
1357 case 'l':
1358 index = 3;
1359 step = -1;
1360 break;
1361 case 'n':
1362 case 'b':
1363 default:
1364 index = 0;
1365 step = 1;
1366 break;
1367 }
1368 for (i = 0; i < 4; i++) {
1369 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1370 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1371 if (leading_zeros) {
1372 if (digits < 3)
1373 *p++ = '0';
1374 if (digits < 2)
1375 *p++ = '0';
1376 }
1377 /* reverse the digits in the quad */
1378 while (digits--)
1379 *p++ = temp[digits];
1380 if (i < 3)
1381 *p++ = '.';
1382 index += step;
1383 }
1384 *p = '\0';
1385
1386 return p;
1387 }
1388
1389 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)1390 char *ip6_compressed_string(char *p, const char *addr)
1391 {
1392 int i, j, range;
1393 unsigned char zerolength[8];
1394 int longest = 1;
1395 int colonpos = -1;
1396 u16 word;
1397 u8 hi, lo;
1398 bool needcolon = false;
1399 bool useIPv4;
1400 struct in6_addr in6;
1401
1402 memcpy(&in6, addr, sizeof(struct in6_addr));
1403
1404 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1405
1406 memset(zerolength, 0, sizeof(zerolength));
1407
1408 if (useIPv4)
1409 range = 6;
1410 else
1411 range = 8;
1412
1413 /* find position of longest 0 run */
1414 for (i = 0; i < range; i++) {
1415 for (j = i; j < range; j++) {
1416 if (in6.s6_addr16[j] != 0)
1417 break;
1418 zerolength[i]++;
1419 }
1420 }
1421 for (i = 0; i < range; i++) {
1422 if (zerolength[i] > longest) {
1423 longest = zerolength[i];
1424 colonpos = i;
1425 }
1426 }
1427 if (longest == 1) /* don't compress a single 0 */
1428 colonpos = -1;
1429
1430 /* emit address */
1431 for (i = 0; i < range; i++) {
1432 if (i == colonpos) {
1433 if (needcolon || i == 0)
1434 *p++ = ':';
1435 *p++ = ':';
1436 needcolon = false;
1437 i += longest - 1;
1438 continue;
1439 }
1440 if (needcolon) {
1441 *p++ = ':';
1442 needcolon = false;
1443 }
1444 /* hex u16 without leading 0s */
1445 word = ntohs(in6.s6_addr16[i]);
1446 hi = word >> 8;
1447 lo = word & 0xff;
1448 if (hi) {
1449 if (hi > 0x0f)
1450 p = hex_byte_pack(p, hi);
1451 else
1452 *p++ = hex_asc_lo(hi);
1453 p = hex_byte_pack(p, lo);
1454 }
1455 else if (lo > 0x0f)
1456 p = hex_byte_pack(p, lo);
1457 else
1458 *p++ = hex_asc_lo(lo);
1459 needcolon = true;
1460 }
1461
1462 if (useIPv4) {
1463 if (needcolon)
1464 *p++ = ':';
1465 p = ip4_string(p, &in6.s6_addr[12], "I4");
1466 }
1467 *p = '\0';
1468
1469 return p;
1470 }
1471
1472 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)1473 char *ip6_string(char *p, const char *addr, const char *fmt)
1474 {
1475 int i;
1476
1477 for (i = 0; i < 8; i++) {
1478 p = hex_byte_pack(p, *addr++);
1479 p = hex_byte_pack(p, *addr++);
1480 if (fmt[0] == 'I' && i != 7)
1481 *p++ = ':';
1482 }
1483 *p = '\0';
1484
1485 return p;
1486 }
1487
1488 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1489 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1490 struct printf_spec spec, const char *fmt)
1491 {
1492 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1493
1494 if (fmt[0] == 'I' && fmt[2] == 'c')
1495 ip6_compressed_string(ip6_addr, addr);
1496 else
1497 ip6_string(ip6_addr, addr, fmt);
1498
1499 return string_nocheck(buf, end, ip6_addr, spec);
1500 }
1501
1502 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1503 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1504 struct printf_spec spec, const char *fmt)
1505 {
1506 char ip4_addr[sizeof("255.255.255.255")];
1507
1508 ip4_string(ip4_addr, addr, fmt);
1509
1510 return string_nocheck(buf, end, ip4_addr, spec);
1511 }
1512
1513 static noinline_for_stack
ip6_addr_string_sa(char * buf,char * end,const struct sockaddr_in6 * sa,struct printf_spec spec,const char * fmt)1514 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1515 struct printf_spec spec, const char *fmt)
1516 {
1517 bool have_p = false, have_s = false, have_f = false, have_c = false;
1518 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1519 sizeof(":12345") + sizeof("/123456789") +
1520 sizeof("%1234567890")];
1521 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1522 const u8 *addr = (const u8 *) &sa->sin6_addr;
1523 char fmt6[2] = { fmt[0], '6' };
1524 u8 off = 0;
1525
1526 fmt++;
1527 while (isalpha(*++fmt)) {
1528 switch (*fmt) {
1529 case 'p':
1530 have_p = true;
1531 break;
1532 case 'f':
1533 have_f = true;
1534 break;
1535 case 's':
1536 have_s = true;
1537 break;
1538 case 'c':
1539 have_c = true;
1540 break;
1541 }
1542 }
1543
1544 if (have_p || have_s || have_f) {
1545 *p = '[';
1546 off = 1;
1547 }
1548
1549 if (fmt6[0] == 'I' && have_c)
1550 p = ip6_compressed_string(ip6_addr + off, addr);
1551 else
1552 p = ip6_string(ip6_addr + off, addr, fmt6);
1553
1554 if (have_p || have_s || have_f)
1555 *p++ = ']';
1556
1557 if (have_p) {
1558 *p++ = ':';
1559 p = number(p, pend, ntohs(sa->sin6_port), spec);
1560 }
1561 if (have_f) {
1562 *p++ = '/';
1563 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1564 IPV6_FLOWINFO_MASK), spec);
1565 }
1566 if (have_s) {
1567 *p++ = '%';
1568 p = number(p, pend, sa->sin6_scope_id, spec);
1569 }
1570 *p = '\0';
1571
1572 return string_nocheck(buf, end, ip6_addr, spec);
1573 }
1574
1575 static noinline_for_stack
ip4_addr_string_sa(char * buf,char * end,const struct sockaddr_in * sa,struct printf_spec spec,const char * fmt)1576 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1577 struct printf_spec spec, const char *fmt)
1578 {
1579 bool have_p = false;
1580 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1581 char *pend = ip4_addr + sizeof(ip4_addr);
1582 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1583 char fmt4[3] = { fmt[0], '4', 0 };
1584
1585 fmt++;
1586 while (isalpha(*++fmt)) {
1587 switch (*fmt) {
1588 case 'p':
1589 have_p = true;
1590 break;
1591 case 'h':
1592 case 'l':
1593 case 'n':
1594 case 'b':
1595 fmt4[2] = *fmt;
1596 break;
1597 }
1598 }
1599
1600 p = ip4_string(ip4_addr, addr, fmt4);
1601 if (have_p) {
1602 *p++ = ':';
1603 p = number(p, pend, ntohs(sa->sin_port), spec);
1604 }
1605 *p = '\0';
1606
1607 return string_nocheck(buf, end, ip4_addr, spec);
1608 }
1609
1610 static noinline_for_stack
ip_addr_string(char * buf,char * end,const void * ptr,struct printf_spec spec,const char * fmt)1611 char *ip_addr_string(char *buf, char *end, const void *ptr,
1612 struct printf_spec spec, const char *fmt)
1613 {
1614 char *err_fmt_msg;
1615
1616 if (check_pointer(&buf, end, ptr, spec))
1617 return buf;
1618
1619 switch (fmt[1]) {
1620 case '6':
1621 return ip6_addr_string(buf, end, ptr, spec, fmt);
1622 case '4':
1623 return ip4_addr_string(buf, end, ptr, spec, fmt);
1624 case 'S': {
1625 const union {
1626 struct sockaddr raw;
1627 struct sockaddr_in v4;
1628 struct sockaddr_in6 v6;
1629 } *sa = ptr;
1630
1631 switch (sa->raw.sa_family) {
1632 case AF_INET:
1633 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1634 case AF_INET6:
1635 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1636 default:
1637 return error_string(buf, end, "(einval)", spec);
1638 }}
1639 }
1640
1641 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1642 return error_string(buf, end, err_fmt_msg, spec);
1643 }
1644
1645 static noinline_for_stack
escaped_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1646 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1647 const char *fmt)
1648 {
1649 bool found = true;
1650 int count = 1;
1651 unsigned int flags = 0;
1652 int len;
1653
1654 if (spec.field_width == 0)
1655 return buf; /* nothing to print */
1656
1657 if (check_pointer(&buf, end, addr, spec))
1658 return buf;
1659
1660 do {
1661 switch (fmt[count++]) {
1662 case 'a':
1663 flags |= ESCAPE_ANY;
1664 break;
1665 case 'c':
1666 flags |= ESCAPE_SPECIAL;
1667 break;
1668 case 'h':
1669 flags |= ESCAPE_HEX;
1670 break;
1671 case 'n':
1672 flags |= ESCAPE_NULL;
1673 break;
1674 case 'o':
1675 flags |= ESCAPE_OCTAL;
1676 break;
1677 case 'p':
1678 flags |= ESCAPE_NP;
1679 break;
1680 case 's':
1681 flags |= ESCAPE_SPACE;
1682 break;
1683 default:
1684 found = false;
1685 break;
1686 }
1687 } while (found);
1688
1689 if (!flags)
1690 flags = ESCAPE_ANY_NP;
1691
1692 len = spec.field_width < 0 ? 1 : spec.field_width;
1693
1694 /*
1695 * string_escape_mem() writes as many characters as it can to
1696 * the given buffer, and returns the total size of the output
1697 * had the buffer been big enough.
1698 */
1699 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1700
1701 return buf;
1702 }
1703
va_format(char * buf,char * end,struct va_format * va_fmt,struct printf_spec spec,const char * fmt)1704 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1705 struct printf_spec spec, const char *fmt)
1706 {
1707 va_list va;
1708
1709 if (check_pointer(&buf, end, va_fmt, spec))
1710 return buf;
1711
1712 va_copy(va, *va_fmt->va);
1713 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1714 va_end(va);
1715
1716 return buf;
1717 }
1718
1719 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1720 char *uuid_string(char *buf, char *end, const u8 *addr,
1721 struct printf_spec spec, const char *fmt)
1722 {
1723 char uuid[UUID_STRING_LEN + 1];
1724 char *p = uuid;
1725 int i;
1726 const u8 *index = uuid_index;
1727 bool uc = false;
1728
1729 if (check_pointer(&buf, end, addr, spec))
1730 return buf;
1731
1732 switch (*(++fmt)) {
1733 case 'L':
1734 uc = true;
1735 fallthrough;
1736 case 'l':
1737 index = guid_index;
1738 break;
1739 case 'B':
1740 uc = true;
1741 break;
1742 }
1743
1744 for (i = 0; i < 16; i++) {
1745 if (uc)
1746 p = hex_byte_pack_upper(p, addr[index[i]]);
1747 else
1748 p = hex_byte_pack(p, addr[index[i]]);
1749 switch (i) {
1750 case 3:
1751 case 5:
1752 case 7:
1753 case 9:
1754 *p++ = '-';
1755 break;
1756 }
1757 }
1758
1759 *p = 0;
1760
1761 return string_nocheck(buf, end, uuid, spec);
1762 }
1763
1764 static noinline_for_stack
netdev_bits(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1765 char *netdev_bits(char *buf, char *end, const void *addr,
1766 struct printf_spec spec, const char *fmt)
1767 {
1768 unsigned long long num;
1769 int size;
1770
1771 if (check_pointer(&buf, end, addr, spec))
1772 return buf;
1773
1774 switch (fmt[1]) {
1775 case 'F':
1776 num = *(const netdev_features_t *)addr;
1777 size = sizeof(netdev_features_t);
1778 break;
1779 default:
1780 return error_string(buf, end, "(%pN?)", spec);
1781 }
1782
1783 return special_hex_number(buf, end, num, size);
1784 }
1785
1786 static noinline_for_stack
fourcc_string(char * buf,char * end,const u32 * fourcc,struct printf_spec spec,const char * fmt)1787 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
1788 struct printf_spec spec, const char *fmt)
1789 {
1790 char output[sizeof("0123 little-endian (0x01234567)")];
1791 char *p = output;
1792 unsigned int i;
1793 u32 orig, val;
1794
1795 if (fmt[1] != 'c' || fmt[2] != 'c')
1796 return error_string(buf, end, "(%p4?)", spec);
1797
1798 if (check_pointer(&buf, end, fourcc, spec))
1799 return buf;
1800
1801 orig = get_unaligned(fourcc);
1802 val = orig & ~BIT(31);
1803
1804 for (i = 0; i < sizeof(u32); i++) {
1805 unsigned char c = val >> (i * 8);
1806
1807 /* Print non-control ASCII characters as-is, dot otherwise */
1808 *p++ = isascii(c) && isprint(c) ? c : '.';
1809 }
1810
1811 strcpy(p, orig & BIT(31) ? " big-endian" : " little-endian");
1812 p += strlen(p);
1813
1814 *p++ = ' ';
1815 *p++ = '(';
1816 p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
1817 *p++ = ')';
1818 *p = '\0';
1819
1820 return string(buf, end, output, spec);
1821 }
1822
1823 static noinline_for_stack
address_val(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1824 char *address_val(char *buf, char *end, const void *addr,
1825 struct printf_spec spec, const char *fmt)
1826 {
1827 unsigned long long num;
1828 int size;
1829
1830 if (check_pointer(&buf, end, addr, spec))
1831 return buf;
1832
1833 switch (fmt[1]) {
1834 case 'd':
1835 num = *(const dma_addr_t *)addr;
1836 size = sizeof(dma_addr_t);
1837 break;
1838 case 'p':
1839 default:
1840 num = *(const phys_addr_t *)addr;
1841 size = sizeof(phys_addr_t);
1842 break;
1843 }
1844
1845 return special_hex_number(buf, end, num, size);
1846 }
1847
1848 static noinline_for_stack
date_str(char * buf,char * end,const struct rtc_time * tm,bool r)1849 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1850 {
1851 int year = tm->tm_year + (r ? 0 : 1900);
1852 int mon = tm->tm_mon + (r ? 0 : 1);
1853
1854 buf = number(buf, end, year, default_dec04_spec);
1855 if (buf < end)
1856 *buf = '-';
1857 buf++;
1858
1859 buf = number(buf, end, mon, default_dec02_spec);
1860 if (buf < end)
1861 *buf = '-';
1862 buf++;
1863
1864 return number(buf, end, tm->tm_mday, default_dec02_spec);
1865 }
1866
1867 static noinline_for_stack
time_str(char * buf,char * end,const struct rtc_time * tm,bool r)1868 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1869 {
1870 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1871 if (buf < end)
1872 *buf = ':';
1873 buf++;
1874
1875 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1876 if (buf < end)
1877 *buf = ':';
1878 buf++;
1879
1880 return number(buf, end, tm->tm_sec, default_dec02_spec);
1881 }
1882
1883 static noinline_for_stack
rtc_str(char * buf,char * end,const struct rtc_time * tm,struct printf_spec spec,const char * fmt)1884 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1885 struct printf_spec spec, const char *fmt)
1886 {
1887 bool have_t = true, have_d = true;
1888 bool raw = false, iso8601_separator = true;
1889 bool found = true;
1890 int count = 2;
1891
1892 if (check_pointer(&buf, end, tm, spec))
1893 return buf;
1894
1895 switch (fmt[count]) {
1896 case 'd':
1897 have_t = false;
1898 count++;
1899 break;
1900 case 't':
1901 have_d = false;
1902 count++;
1903 break;
1904 }
1905
1906 do {
1907 switch (fmt[count++]) {
1908 case 'r':
1909 raw = true;
1910 break;
1911 case 's':
1912 iso8601_separator = false;
1913 break;
1914 default:
1915 found = false;
1916 break;
1917 }
1918 } while (found);
1919
1920 if (have_d)
1921 buf = date_str(buf, end, tm, raw);
1922 if (have_d && have_t) {
1923 if (buf < end)
1924 *buf = iso8601_separator ? 'T' : ' ';
1925 buf++;
1926 }
1927 if (have_t)
1928 buf = time_str(buf, end, tm, raw);
1929
1930 return buf;
1931 }
1932
1933 static noinline_for_stack
time64_str(char * buf,char * end,const time64_t time,struct printf_spec spec,const char * fmt)1934 char *time64_str(char *buf, char *end, const time64_t time,
1935 struct printf_spec spec, const char *fmt)
1936 {
1937 struct rtc_time rtc_time;
1938 struct tm tm;
1939
1940 time64_to_tm(time, 0, &tm);
1941
1942 rtc_time.tm_sec = tm.tm_sec;
1943 rtc_time.tm_min = tm.tm_min;
1944 rtc_time.tm_hour = tm.tm_hour;
1945 rtc_time.tm_mday = tm.tm_mday;
1946 rtc_time.tm_mon = tm.tm_mon;
1947 rtc_time.tm_year = tm.tm_year;
1948 rtc_time.tm_wday = tm.tm_wday;
1949 rtc_time.tm_yday = tm.tm_yday;
1950
1951 rtc_time.tm_isdst = 0;
1952
1953 return rtc_str(buf, end, &rtc_time, spec, fmt);
1954 }
1955
1956 static noinline_for_stack
time_and_date(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)1957 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1958 const char *fmt)
1959 {
1960 switch (fmt[1]) {
1961 case 'R':
1962 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1963 case 'T':
1964 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1965 default:
1966 return error_string(buf, end, "(%pt?)", spec);
1967 }
1968 }
1969
1970 static noinline_for_stack
clock(char * buf,char * end,struct clk * clk,struct printf_spec spec,const char * fmt)1971 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1972 const char *fmt)
1973 {
1974 if (!IS_ENABLED(CONFIG_HAVE_CLK))
1975 return error_string(buf, end, "(%pC?)", spec);
1976
1977 if (check_pointer(&buf, end, clk, spec))
1978 return buf;
1979
1980 switch (fmt[1]) {
1981 case 'n':
1982 default:
1983 #ifdef CONFIG_COMMON_CLK
1984 return string(buf, end, __clk_get_name(clk), spec);
1985 #else
1986 return ptr_to_id(buf, end, clk, spec);
1987 #endif
1988 }
1989 }
1990
1991 static
format_flags(char * buf,char * end,unsigned long flags,const struct trace_print_flags * names)1992 char *format_flags(char *buf, char *end, unsigned long flags,
1993 const struct trace_print_flags *names)
1994 {
1995 unsigned long mask;
1996
1997 for ( ; flags && names->name; names++) {
1998 mask = names->mask;
1999 if ((flags & mask) != mask)
2000 continue;
2001
2002 buf = string(buf, end, names->name, default_str_spec);
2003
2004 flags &= ~mask;
2005 if (flags) {
2006 if (buf < end)
2007 *buf = '|';
2008 buf++;
2009 }
2010 }
2011
2012 if (flags)
2013 buf = number(buf, end, flags, default_flag_spec);
2014
2015 return buf;
2016 }
2017
2018 struct page_flags_fields {
2019 int width;
2020 int shift;
2021 int mask;
2022 const struct printf_spec *spec;
2023 const char *name;
2024 };
2025
2026 static const struct page_flags_fields pff[] = {
2027 {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
2028 &default_dec_spec, "section"},
2029 {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
2030 &default_dec_spec, "node"},
2031 {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
2032 &default_dec_spec, "zone"},
2033 {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
2034 &default_flag_spec, "lastcpupid"},
2035 {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
2036 &default_flag_spec, "kasantag"},
2037 };
2038
2039 static
format_page_flags(char * buf,char * end,unsigned long flags)2040 char *format_page_flags(char *buf, char *end, unsigned long flags)
2041 {
2042 unsigned long main_flags = flags & PAGEFLAGS_MASK;
2043 bool append = false;
2044 int i;
2045
2046 /* Page flags from the main area. */
2047 if (main_flags) {
2048 buf = format_flags(buf, end, main_flags, pageflag_names);
2049 append = true;
2050 }
2051
2052 /* Page flags from the fields area */
2053 for (i = 0; i < ARRAY_SIZE(pff); i++) {
2054 /* Skip undefined fields. */
2055 if (!pff[i].width)
2056 continue;
2057
2058 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2059 if (append) {
2060 if (buf < end)
2061 *buf = '|';
2062 buf++;
2063 }
2064
2065 buf = string(buf, end, pff[i].name, default_str_spec);
2066 if (buf < end)
2067 *buf = '=';
2068 buf++;
2069 buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
2070 *pff[i].spec);
2071
2072 append = true;
2073 }
2074
2075 return buf;
2076 }
2077
2078 static noinline_for_stack
flags_string(char * buf,char * end,void * flags_ptr,struct printf_spec spec,const char * fmt)2079 char *flags_string(char *buf, char *end, void *flags_ptr,
2080 struct printf_spec spec, const char *fmt)
2081 {
2082 unsigned long flags;
2083 const struct trace_print_flags *names;
2084
2085 if (check_pointer(&buf, end, flags_ptr, spec))
2086 return buf;
2087
2088 switch (fmt[1]) {
2089 case 'p':
2090 return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
2091 case 'v':
2092 flags = *(unsigned long *)flags_ptr;
2093 names = vmaflag_names;
2094 break;
2095 case 'g':
2096 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
2097 names = gfpflag_names;
2098 break;
2099 default:
2100 return error_string(buf, end, "(%pG?)", spec);
2101 }
2102
2103 return format_flags(buf, end, flags, names);
2104 }
2105
2106 static noinline_for_stack
fwnode_full_name_string(struct fwnode_handle * fwnode,char * buf,char * end)2107 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
2108 char *end)
2109 {
2110 int depth;
2111
2112 /* Loop starting from the root node to the current node. */
2113 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
2114 /*
2115 * Only get a reference for other nodes (i.e. parent nodes).
2116 * fwnode refcount may be 0 here.
2117 */
2118 struct fwnode_handle *__fwnode = depth ?
2119 fwnode_get_nth_parent(fwnode, depth) : fwnode;
2120
2121 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
2122 default_str_spec);
2123 buf = string(buf, end, fwnode_get_name(__fwnode),
2124 default_str_spec);
2125
2126 if (depth)
2127 fwnode_handle_put(__fwnode);
2128 }
2129
2130 return buf;
2131 }
2132
2133 static noinline_for_stack
device_node_string(char * buf,char * end,struct device_node * dn,struct printf_spec spec,const char * fmt)2134 char *device_node_string(char *buf, char *end, struct device_node *dn,
2135 struct printf_spec spec, const char *fmt)
2136 {
2137 char tbuf[sizeof("xxxx") + 1];
2138 const char *p;
2139 int ret;
2140 char *buf_start = buf;
2141 struct property *prop;
2142 bool has_mult, pass;
2143
2144 struct printf_spec str_spec = spec;
2145 str_spec.field_width = -1;
2146
2147 if (fmt[0] != 'F')
2148 return error_string(buf, end, "(%pO?)", spec);
2149
2150 if (!IS_ENABLED(CONFIG_OF))
2151 return error_string(buf, end, "(%pOF?)", spec);
2152
2153 if (check_pointer(&buf, end, dn, spec))
2154 return buf;
2155
2156 /* simple case without anything any more format specifiers */
2157 fmt++;
2158 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2159 fmt = "f";
2160
2161 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2162 int precision;
2163 if (pass) {
2164 if (buf < end)
2165 *buf = ':';
2166 buf++;
2167 }
2168
2169 switch (*fmt) {
2170 case 'f': /* full_name */
2171 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2172 end);
2173 break;
2174 case 'n': /* name */
2175 p = fwnode_get_name(of_fwnode_handle(dn));
2176 precision = str_spec.precision;
2177 str_spec.precision = strchrnul(p, '@') - p;
2178 buf = string(buf, end, p, str_spec);
2179 str_spec.precision = precision;
2180 break;
2181 case 'p': /* phandle */
2182 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2183 break;
2184 case 'P': /* path-spec */
2185 p = fwnode_get_name(of_fwnode_handle(dn));
2186 if (!p[1])
2187 p = "/";
2188 buf = string(buf, end, p, str_spec);
2189 break;
2190 case 'F': /* flags */
2191 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2192 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2193 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2194 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2195 tbuf[4] = 0;
2196 buf = string_nocheck(buf, end, tbuf, str_spec);
2197 break;
2198 case 'c': /* major compatible string */
2199 ret = of_property_read_string(dn, "compatible", &p);
2200 if (!ret)
2201 buf = string(buf, end, p, str_spec);
2202 break;
2203 case 'C': /* full compatible string */
2204 has_mult = false;
2205 of_property_for_each_string(dn, "compatible", prop, p) {
2206 if (has_mult)
2207 buf = string_nocheck(buf, end, ",", str_spec);
2208 buf = string_nocheck(buf, end, "\"", str_spec);
2209 buf = string(buf, end, p, str_spec);
2210 buf = string_nocheck(buf, end, "\"", str_spec);
2211
2212 has_mult = true;
2213 }
2214 break;
2215 default:
2216 break;
2217 }
2218 }
2219
2220 return widen_string(buf, buf - buf_start, end, spec);
2221 }
2222
2223 static noinline_for_stack
fwnode_string(char * buf,char * end,struct fwnode_handle * fwnode,struct printf_spec spec,const char * fmt)2224 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2225 struct printf_spec spec, const char *fmt)
2226 {
2227 struct printf_spec str_spec = spec;
2228 char *buf_start = buf;
2229
2230 str_spec.field_width = -1;
2231
2232 if (*fmt != 'w')
2233 return error_string(buf, end, "(%pf?)", spec);
2234
2235 if (check_pointer(&buf, end, fwnode, spec))
2236 return buf;
2237
2238 fmt++;
2239
2240 switch (*fmt) {
2241 case 'P': /* name */
2242 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2243 break;
2244 case 'f': /* full_name */
2245 default:
2246 buf = fwnode_full_name_string(fwnode, buf, end);
2247 break;
2248 }
2249
2250 return widen_string(buf, buf - buf_start, end, spec);
2251 }
2252
no_hash_pointers_enable(char * str)2253 int __init no_hash_pointers_enable(char *str)
2254 {
2255 if (no_hash_pointers)
2256 return 0;
2257
2258 no_hash_pointers = true;
2259
2260 pr_warn("**********************************************************\n");
2261 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2262 pr_warn("** **\n");
2263 pr_warn("** This system shows unhashed kernel memory addresses **\n");
2264 pr_warn("** via the console, logs, and other interfaces. This **\n");
2265 pr_warn("** might reduce the security of your system. **\n");
2266 pr_warn("** **\n");
2267 pr_warn("** If you see this message and you are not debugging **\n");
2268 pr_warn("** the kernel, report this immediately to your system **\n");
2269 pr_warn("** administrator! **\n");
2270 pr_warn("** **\n");
2271 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2272 pr_warn("**********************************************************\n");
2273
2274 return 0;
2275 }
2276 early_param("no_hash_pointers", no_hash_pointers_enable);
2277
2278 /*
2279 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2280 * by an extra set of alphanumeric characters that are extended format
2281 * specifiers.
2282 *
2283 * Please update scripts/checkpatch.pl when adding/removing conversion
2284 * characters. (Search for "check for vsprintf extension").
2285 *
2286 * Right now we handle:
2287 *
2288 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2289 * - 's' For symbolic direct pointers (or function descriptors) without offset
2290 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2291 * - 'S[R]b' as above with module build ID (for use in backtraces)
2292 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2293 * %ps and %pS. Be careful when re-using these specifiers.
2294 * - 'B' For backtraced symbolic direct pointers with offset
2295 * - 'Bb' as above with module build ID (for use in backtraces)
2296 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2297 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2298 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2299 * width which must be explicitly specified either as part of the
2300 * format string '%32b[l]' or through '%*b[l]', [l] selects
2301 * range-list format instead of hex format
2302 * - 'M' For a 6-byte MAC address, it prints the address in the
2303 * usual colon-separated hex notation
2304 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2305 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2306 * with a dash-separated hex notation
2307 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2308 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2309 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2310 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2311 * [S][pfs]
2312 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2313 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2314 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2315 * IPv6 omits the colons (01020304...0f)
2316 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2317 * [S][pfs]
2318 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2319 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2320 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2321 * - 'I[6S]c' for IPv6 addresses printed as specified by
2322 * https://tools.ietf.org/html/rfc5952
2323 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2324 * of the following flags (see string_escape_mem() for the
2325 * details):
2326 * a - ESCAPE_ANY
2327 * c - ESCAPE_SPECIAL
2328 * h - ESCAPE_HEX
2329 * n - ESCAPE_NULL
2330 * o - ESCAPE_OCTAL
2331 * p - ESCAPE_NP
2332 * s - ESCAPE_SPACE
2333 * By default ESCAPE_ANY_NP is used.
2334 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2335 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2336 * Options for %pU are:
2337 * b big endian lower case hex (default)
2338 * B big endian UPPER case hex
2339 * l little endian lower case hex
2340 * L little endian UPPER case hex
2341 * big endian output byte order is:
2342 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2343 * little endian output byte order is:
2344 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2345 * - 'V' For a struct va_format which contains a format string * and va_list *,
2346 * call vsnprintf(->format, *->va_list).
2347 * Implements a "recursive vsnprintf".
2348 * Do not use this feature without some mechanism to verify the
2349 * correctness of the format string and va_list arguments.
2350 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2351 * Use only for procfs, sysfs and similar files, not printk(); please
2352 * read the documentation (path below) first.
2353 * - 'NF' For a netdev_features_t
2354 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2355 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2356 * a certain separator (' ' by default):
2357 * C colon
2358 * D dash
2359 * N no separator
2360 * The maximum supported length is 64 bytes of the input. Consider
2361 * to use print_hex_dump() for the larger input.
2362 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2363 * (default assumed to be phys_addr_t, passed by reference)
2364 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2365 * - 'D[234]' Same as 'd' but for a struct file
2366 * - 'g' For block_device name (gendisk + partition number)
2367 * - 't[RT][dt][r][s]' For time and date as represented by:
2368 * R struct rtc_time
2369 * T time64_t
2370 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2371 * (legacy clock framework) of the clock
2372 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2373 * (legacy clock framework) of the clock
2374 * - 'G' For flags to be printed as a collection of symbolic strings that would
2375 * construct the specific value. Supported flags given by option:
2376 * p page flags (see struct page) given as pointer to unsigned long
2377 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2378 * v vma flags (VM_*) given as pointer to unsigned long
2379 * - 'OF[fnpPcCF]' For a device tree object
2380 * Without any optional arguments prints the full_name
2381 * f device node full_name
2382 * n device node name
2383 * p device node phandle
2384 * P device node path spec (name + @unit)
2385 * F device node flags
2386 * c major compatible string
2387 * C full compatible string
2388 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2389 * Without an option prints the full name of the node
2390 * f full name
2391 * P node name, including a possible unit address
2392 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2393 * Please read the documentation (path below) before using!
2394 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2395 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2396 * or user (u) memory to probe, and:
2397 * s a string, equivalent to "%s" on direct vsnprintf() use
2398 *
2399 * ** When making changes please also update:
2400 * Documentation/core-api/printk-formats.rst
2401 *
2402 * Note: The default behaviour (unadorned %p) is to hash the address,
2403 * rendering it useful as a unique identifier.
2404 */
2405 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2406 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2407 struct printf_spec spec)
2408 {
2409 switch (*fmt) {
2410 case 'S':
2411 case 's':
2412 ptr = dereference_symbol_descriptor(ptr);
2413 fallthrough;
2414 case 'B':
2415 return symbol_string(buf, end, ptr, spec, fmt);
2416 case 'R':
2417 case 'r':
2418 return resource_string(buf, end, ptr, spec, fmt);
2419 case 'h':
2420 return hex_string(buf, end, ptr, spec, fmt);
2421 case 'b':
2422 switch (fmt[1]) {
2423 case 'l':
2424 return bitmap_list_string(buf, end, ptr, spec, fmt);
2425 default:
2426 return bitmap_string(buf, end, ptr, spec, fmt);
2427 }
2428 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2429 case 'm': /* Contiguous: 000102030405 */
2430 /* [mM]F (FDDI) */
2431 /* [mM]R (Reverse order; Bluetooth) */
2432 return mac_address_string(buf, end, ptr, spec, fmt);
2433 case 'I': /* Formatted IP supported
2434 * 4: 1.2.3.4
2435 * 6: 0001:0203:...:0708
2436 * 6c: 1::708 or 1::1.2.3.4
2437 */
2438 case 'i': /* Contiguous:
2439 * 4: 001.002.003.004
2440 * 6: 000102...0f
2441 */
2442 return ip_addr_string(buf, end, ptr, spec, fmt);
2443 case 'E':
2444 return escaped_string(buf, end, ptr, spec, fmt);
2445 case 'U':
2446 return uuid_string(buf, end, ptr, spec, fmt);
2447 case 'V':
2448 return va_format(buf, end, ptr, spec, fmt);
2449 case 'K':
2450 return restricted_pointer(buf, end, ptr, spec);
2451 case 'N':
2452 return netdev_bits(buf, end, ptr, spec, fmt);
2453 case '4':
2454 return fourcc_string(buf, end, ptr, spec, fmt);
2455 case 'a':
2456 return address_val(buf, end, ptr, spec, fmt);
2457 case 'd':
2458 return dentry_name(buf, end, ptr, spec, fmt);
2459 case 't':
2460 return time_and_date(buf, end, ptr, spec, fmt);
2461 case 'C':
2462 return clock(buf, end, ptr, spec, fmt);
2463 case 'D':
2464 return file_dentry_name(buf, end, ptr, spec, fmt);
2465 #ifdef CONFIG_BLOCK
2466 case 'g':
2467 return bdev_name(buf, end, ptr, spec, fmt);
2468 #endif
2469
2470 case 'G':
2471 return flags_string(buf, end, ptr, spec, fmt);
2472 case 'O':
2473 return device_node_string(buf, end, ptr, spec, fmt + 1);
2474 case 'f':
2475 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2476 case 'x':
2477 return pointer_string(buf, end, ptr, spec);
2478 case 'e':
2479 /* %pe with a non-ERR_PTR gets treated as plain %p */
2480 if (!IS_ERR(ptr))
2481 return default_pointer(buf, end, ptr, spec);
2482 return err_ptr(buf, end, ptr, spec);
2483 case 'u':
2484 case 'k':
2485 switch (fmt[1]) {
2486 case 's':
2487 return string(buf, end, ptr, spec);
2488 default:
2489 return error_string(buf, end, "(einval)", spec);
2490 }
2491 default:
2492 return default_pointer(buf, end, ptr, spec);
2493 }
2494 }
2495
2496 /*
2497 * Helper function to decode printf style format.
2498 * Each call decode a token from the format and return the
2499 * number of characters read (or likely the delta where it wants
2500 * to go on the next call).
2501 * The decoded token is returned through the parameters
2502 *
2503 * 'h', 'l', or 'L' for integer fields
2504 * 'z' support added 23/7/1999 S.H.
2505 * 'z' changed to 'Z' --davidm 1/25/99
2506 * 'Z' changed to 'z' --adobriyan 2017-01-25
2507 * 't' added for ptrdiff_t
2508 *
2509 * @fmt: the format string
2510 * @type of the token returned
2511 * @flags: various flags such as +, -, # tokens..
2512 * @field_width: overwritten width
2513 * @base: base of the number (octal, hex, ...)
2514 * @precision: precision of a number
2515 * @qualifier: qualifier of a number (long, size_t, ...)
2516 */
2517 static noinline_for_stack
format_decode(const char * fmt,struct printf_spec * spec)2518 int format_decode(const char *fmt, struct printf_spec *spec)
2519 {
2520 const char *start = fmt;
2521 char qualifier;
2522
2523 /* we finished early by reading the field width */
2524 if (spec->type == FORMAT_TYPE_WIDTH) {
2525 if (spec->field_width < 0) {
2526 spec->field_width = -spec->field_width;
2527 spec->flags |= LEFT;
2528 }
2529 spec->type = FORMAT_TYPE_NONE;
2530 goto precision;
2531 }
2532
2533 /* we finished early by reading the precision */
2534 if (spec->type == FORMAT_TYPE_PRECISION) {
2535 if (spec->precision < 0)
2536 spec->precision = 0;
2537
2538 spec->type = FORMAT_TYPE_NONE;
2539 goto qualifier;
2540 }
2541
2542 /* By default */
2543 spec->type = FORMAT_TYPE_NONE;
2544
2545 for (; *fmt ; ++fmt) {
2546 if (*fmt == '%')
2547 break;
2548 }
2549
2550 /* Return the current non-format string */
2551 if (fmt != start || !*fmt)
2552 return fmt - start;
2553
2554 /* Process flags */
2555 spec->flags = 0;
2556
2557 while (1) { /* this also skips first '%' */
2558 bool found = true;
2559
2560 ++fmt;
2561
2562 switch (*fmt) {
2563 case '-': spec->flags |= LEFT; break;
2564 case '+': spec->flags |= PLUS; break;
2565 case ' ': spec->flags |= SPACE; break;
2566 case '#': spec->flags |= SPECIAL; break;
2567 case '0': spec->flags |= ZEROPAD; break;
2568 default: found = false;
2569 }
2570
2571 if (!found)
2572 break;
2573 }
2574
2575 /* get field width */
2576 spec->field_width = -1;
2577
2578 if (isdigit(*fmt))
2579 spec->field_width = skip_atoi(&fmt);
2580 else if (*fmt == '*') {
2581 /* it's the next argument */
2582 spec->type = FORMAT_TYPE_WIDTH;
2583 return ++fmt - start;
2584 }
2585
2586 precision:
2587 /* get the precision */
2588 spec->precision = -1;
2589 if (*fmt == '.') {
2590 ++fmt;
2591 if (isdigit(*fmt)) {
2592 spec->precision = skip_atoi(&fmt);
2593 if (spec->precision < 0)
2594 spec->precision = 0;
2595 } else if (*fmt == '*') {
2596 /* it's the next argument */
2597 spec->type = FORMAT_TYPE_PRECISION;
2598 return ++fmt - start;
2599 }
2600 }
2601
2602 qualifier:
2603 /* get the conversion qualifier */
2604 qualifier = 0;
2605 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2606 *fmt == 'z' || *fmt == 't') {
2607 qualifier = *fmt++;
2608 if (unlikely(qualifier == *fmt)) {
2609 if (qualifier == 'l') {
2610 qualifier = 'L';
2611 ++fmt;
2612 } else if (qualifier == 'h') {
2613 qualifier = 'H';
2614 ++fmt;
2615 }
2616 }
2617 }
2618
2619 /* default base */
2620 spec->base = 10;
2621 switch (*fmt) {
2622 case 'c':
2623 spec->type = FORMAT_TYPE_CHAR;
2624 return ++fmt - start;
2625
2626 case 's':
2627 spec->type = FORMAT_TYPE_STR;
2628 return ++fmt - start;
2629
2630 case 'p':
2631 spec->type = FORMAT_TYPE_PTR;
2632 return ++fmt - start;
2633
2634 case '%':
2635 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2636 return ++fmt - start;
2637
2638 /* integer number formats - set up the flags and "break" */
2639 case 'o':
2640 spec->base = 8;
2641 break;
2642
2643 case 'x':
2644 spec->flags |= SMALL;
2645 fallthrough;
2646
2647 case 'X':
2648 spec->base = 16;
2649 break;
2650
2651 case 'd':
2652 case 'i':
2653 spec->flags |= SIGN;
2654 break;
2655 case 'u':
2656 break;
2657
2658 case 'n':
2659 /*
2660 * Since %n poses a greater security risk than
2661 * utility, treat it as any other invalid or
2662 * unsupported format specifier.
2663 */
2664 fallthrough;
2665
2666 default:
2667 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2668 spec->type = FORMAT_TYPE_INVALID;
2669 return fmt - start;
2670 }
2671
2672 if (qualifier == 'L')
2673 spec->type = FORMAT_TYPE_LONG_LONG;
2674 else if (qualifier == 'l') {
2675 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2676 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2677 } else if (qualifier == 'z') {
2678 spec->type = FORMAT_TYPE_SIZE_T;
2679 } else if (qualifier == 't') {
2680 spec->type = FORMAT_TYPE_PTRDIFF;
2681 } else if (qualifier == 'H') {
2682 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2683 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2684 } else if (qualifier == 'h') {
2685 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2686 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2687 } else {
2688 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2689 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2690 }
2691
2692 return ++fmt - start;
2693 }
2694
2695 static void
set_field_width(struct printf_spec * spec,int width)2696 set_field_width(struct printf_spec *spec, int width)
2697 {
2698 spec->field_width = width;
2699 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2700 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2701 }
2702 }
2703
2704 static void
set_precision(struct printf_spec * spec,int prec)2705 set_precision(struct printf_spec *spec, int prec)
2706 {
2707 spec->precision = prec;
2708 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2709 spec->precision = clamp(prec, 0, PRECISION_MAX);
2710 }
2711 }
2712
2713 /**
2714 * vsnprintf - Format a string and place it in a buffer
2715 * @buf: The buffer to place the result into
2716 * @size: The size of the buffer, including the trailing null space
2717 * @fmt: The format string to use
2718 * @args: Arguments for the format string
2719 *
2720 * This function generally follows C99 vsnprintf, but has some
2721 * extensions and a few limitations:
2722 *
2723 * - ``%n`` is unsupported
2724 * - ``%p*`` is handled by pointer()
2725 *
2726 * See pointer() or Documentation/core-api/printk-formats.rst for more
2727 * extensive description.
2728 *
2729 * **Please update the documentation in both places when making changes**
2730 *
2731 * The return value is the number of characters which would
2732 * be generated for the given input, excluding the trailing
2733 * '\0', as per ISO C99. If you want to have the exact
2734 * number of characters written into @buf as return value
2735 * (not including the trailing '\0'), use vscnprintf(). If the
2736 * return is greater than or equal to @size, the resulting
2737 * string is truncated.
2738 *
2739 * If you're not already dealing with a va_list consider using snprintf().
2740 */
vsnprintf(char * buf,size_t size,const char * fmt,va_list args)2741 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2742 {
2743 unsigned long long num;
2744 char *str, *end;
2745 struct printf_spec spec = {0};
2746
2747 /* Reject out-of-range values early. Large positive sizes are
2748 used for unknown buffer sizes. */
2749 if (WARN_ON_ONCE(size > INT_MAX))
2750 return 0;
2751
2752 str = buf;
2753 end = buf + size;
2754
2755 /* Make sure end is always >= buf */
2756 if (end < buf) {
2757 end = ((void *)-1);
2758 size = end - buf;
2759 }
2760
2761 while (*fmt) {
2762 const char *old_fmt = fmt;
2763 int read = format_decode(fmt, &spec);
2764
2765 fmt += read;
2766
2767 switch (spec.type) {
2768 case FORMAT_TYPE_NONE: {
2769 int copy = read;
2770 if (str < end) {
2771 if (copy > end - str)
2772 copy = end - str;
2773 memcpy(str, old_fmt, copy);
2774 }
2775 str += read;
2776 break;
2777 }
2778
2779 case FORMAT_TYPE_WIDTH:
2780 set_field_width(&spec, va_arg(args, int));
2781 break;
2782
2783 case FORMAT_TYPE_PRECISION:
2784 set_precision(&spec, va_arg(args, int));
2785 break;
2786
2787 case FORMAT_TYPE_CHAR: {
2788 char c;
2789
2790 if (!(spec.flags & LEFT)) {
2791 while (--spec.field_width > 0) {
2792 if (str < end)
2793 *str = ' ';
2794 ++str;
2795
2796 }
2797 }
2798 c = (unsigned char) va_arg(args, int);
2799 if (str < end)
2800 *str = c;
2801 ++str;
2802 while (--spec.field_width > 0) {
2803 if (str < end)
2804 *str = ' ';
2805 ++str;
2806 }
2807 break;
2808 }
2809
2810 case FORMAT_TYPE_STR:
2811 str = string(str, end, va_arg(args, char *), spec);
2812 break;
2813
2814 case FORMAT_TYPE_PTR:
2815 str = pointer(fmt, str, end, va_arg(args, void *),
2816 spec);
2817 while (isalnum(*fmt))
2818 fmt++;
2819 break;
2820
2821 case FORMAT_TYPE_PERCENT_CHAR:
2822 if (str < end)
2823 *str = '%';
2824 ++str;
2825 break;
2826
2827 case FORMAT_TYPE_INVALID:
2828 /*
2829 * Presumably the arguments passed gcc's type
2830 * checking, but there is no safe or sane way
2831 * for us to continue parsing the format and
2832 * fetching from the va_list; the remaining
2833 * specifiers and arguments would be out of
2834 * sync.
2835 */
2836 goto out;
2837
2838 default:
2839 switch (spec.type) {
2840 case FORMAT_TYPE_LONG_LONG:
2841 num = va_arg(args, long long);
2842 break;
2843 case FORMAT_TYPE_ULONG:
2844 num = va_arg(args, unsigned long);
2845 break;
2846 case FORMAT_TYPE_LONG:
2847 num = va_arg(args, long);
2848 break;
2849 case FORMAT_TYPE_SIZE_T:
2850 if (spec.flags & SIGN)
2851 num = va_arg(args, ssize_t);
2852 else
2853 num = va_arg(args, size_t);
2854 break;
2855 case FORMAT_TYPE_PTRDIFF:
2856 num = va_arg(args, ptrdiff_t);
2857 break;
2858 case FORMAT_TYPE_UBYTE:
2859 num = (unsigned char) va_arg(args, int);
2860 break;
2861 case FORMAT_TYPE_BYTE:
2862 num = (signed char) va_arg(args, int);
2863 break;
2864 case FORMAT_TYPE_USHORT:
2865 num = (unsigned short) va_arg(args, int);
2866 break;
2867 case FORMAT_TYPE_SHORT:
2868 num = (short) va_arg(args, int);
2869 break;
2870 case FORMAT_TYPE_INT:
2871 num = (int) va_arg(args, int);
2872 break;
2873 default:
2874 num = va_arg(args, unsigned int);
2875 }
2876
2877 str = number(str, end, num, spec);
2878 }
2879 }
2880
2881 out:
2882 if (size > 0) {
2883 if (str < end)
2884 *str = '\0';
2885 else
2886 end[-1] = '\0';
2887 }
2888
2889 /* the trailing null byte doesn't count towards the total */
2890 return str-buf;
2891
2892 }
2893 EXPORT_SYMBOL(vsnprintf);
2894
2895 /**
2896 * vscnprintf - Format a string and place it in a buffer
2897 * @buf: The buffer to place the result into
2898 * @size: The size of the buffer, including the trailing null space
2899 * @fmt: The format string to use
2900 * @args: Arguments for the format string
2901 *
2902 * The return value is the number of characters which have been written into
2903 * the @buf not including the trailing '\0'. If @size is == 0 the function
2904 * returns 0.
2905 *
2906 * If you're not already dealing with a va_list consider using scnprintf().
2907 *
2908 * See the vsnprintf() documentation for format string extensions over C99.
2909 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)2910 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2911 {
2912 int i;
2913
2914 i = vsnprintf(buf, size, fmt, args);
2915
2916 if (likely(i < size))
2917 return i;
2918 if (size != 0)
2919 return size - 1;
2920 return 0;
2921 }
2922 EXPORT_SYMBOL(vscnprintf);
2923
2924 /**
2925 * snprintf - Format a string and place it in a buffer
2926 * @buf: The buffer to place the result into
2927 * @size: The size of the buffer, including the trailing null space
2928 * @fmt: The format string to use
2929 * @...: Arguments for the format string
2930 *
2931 * The return value is the number of characters which would be
2932 * generated for the given input, excluding the trailing null,
2933 * as per ISO C99. If the return is greater than or equal to
2934 * @size, the resulting string is truncated.
2935 *
2936 * See the vsnprintf() documentation for format string extensions over C99.
2937 */
snprintf(char * buf,size_t size,const char * fmt,...)2938 int snprintf(char *buf, size_t size, const char *fmt, ...)
2939 {
2940 va_list args;
2941 int i;
2942
2943 va_start(args, fmt);
2944 i = vsnprintf(buf, size, fmt, args);
2945 va_end(args);
2946
2947 return i;
2948 }
2949 EXPORT_SYMBOL(snprintf);
2950
2951 /**
2952 * scnprintf - Format a string and place it in a buffer
2953 * @buf: The buffer to place the result into
2954 * @size: The size of the buffer, including the trailing null space
2955 * @fmt: The format string to use
2956 * @...: Arguments for the format string
2957 *
2958 * The return value is the number of characters written into @buf not including
2959 * the trailing '\0'. If @size is == 0 the function returns 0.
2960 */
2961
scnprintf(char * buf,size_t size,const char * fmt,...)2962 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2963 {
2964 va_list args;
2965 int i;
2966
2967 va_start(args, fmt);
2968 i = vscnprintf(buf, size, fmt, args);
2969 va_end(args);
2970
2971 return i;
2972 }
2973 EXPORT_SYMBOL(scnprintf);
2974
2975 /**
2976 * vsprintf - Format a string and place it in a buffer
2977 * @buf: The buffer to place the result into
2978 * @fmt: The format string to use
2979 * @args: Arguments for the format string
2980 *
2981 * The function returns the number of characters written
2982 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2983 * buffer overflows.
2984 *
2985 * If you're not already dealing with a va_list consider using sprintf().
2986 *
2987 * See the vsnprintf() documentation for format string extensions over C99.
2988 */
vsprintf(char * buf,const char * fmt,va_list args)2989 int vsprintf(char *buf, const char *fmt, va_list args)
2990 {
2991 return vsnprintf(buf, INT_MAX, fmt, args);
2992 }
2993 EXPORT_SYMBOL(vsprintf);
2994
2995 /**
2996 * sprintf - Format a string and place it in a buffer
2997 * @buf: The buffer to place the result into
2998 * @fmt: The format string to use
2999 * @...: Arguments for the format string
3000 *
3001 * The function returns the number of characters written
3002 * into @buf. Use snprintf() or scnprintf() in order to avoid
3003 * buffer overflows.
3004 *
3005 * See the vsnprintf() documentation for format string extensions over C99.
3006 */
sprintf(char * buf,const char * fmt,...)3007 int sprintf(char *buf, const char *fmt, ...)
3008 {
3009 va_list args;
3010 int i;
3011
3012 va_start(args, fmt);
3013 i = vsnprintf(buf, INT_MAX, fmt, args);
3014 va_end(args);
3015
3016 return i;
3017 }
3018 EXPORT_SYMBOL(sprintf);
3019
3020 #ifdef CONFIG_BINARY_PRINTF
3021 /*
3022 * bprintf service:
3023 * vbin_printf() - VA arguments to binary data
3024 * bstr_printf() - Binary data to text string
3025 */
3026
3027 /**
3028 * vbin_printf - Parse a format string and place args' binary value in a buffer
3029 * @bin_buf: The buffer to place args' binary value
3030 * @size: The size of the buffer(by words(32bits), not characters)
3031 * @fmt: The format string to use
3032 * @args: Arguments for the format string
3033 *
3034 * The format follows C99 vsnprintf, except %n is ignored, and its argument
3035 * is skipped.
3036 *
3037 * The return value is the number of words(32bits) which would be generated for
3038 * the given input.
3039 *
3040 * NOTE:
3041 * If the return value is greater than @size, the resulting bin_buf is NOT
3042 * valid for bstr_printf().
3043 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt,va_list args)3044 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
3045 {
3046 struct printf_spec spec = {0};
3047 char *str, *end;
3048 int width;
3049
3050 str = (char *)bin_buf;
3051 end = (char *)(bin_buf + size);
3052
3053 #define save_arg(type) \
3054 ({ \
3055 unsigned long long value; \
3056 if (sizeof(type) == 8) { \
3057 unsigned long long val8; \
3058 str = PTR_ALIGN(str, sizeof(u32)); \
3059 val8 = va_arg(args, unsigned long long); \
3060 if (str + sizeof(type) <= end) { \
3061 *(u32 *)str = *(u32 *)&val8; \
3062 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
3063 } \
3064 value = val8; \
3065 } else { \
3066 unsigned int val4; \
3067 str = PTR_ALIGN(str, sizeof(type)); \
3068 val4 = va_arg(args, int); \
3069 if (str + sizeof(type) <= end) \
3070 *(typeof(type) *)str = (type)(long)val4; \
3071 value = (unsigned long long)val4; \
3072 } \
3073 str += sizeof(type); \
3074 value; \
3075 })
3076
3077 while (*fmt) {
3078 int read = format_decode(fmt, &spec);
3079
3080 fmt += read;
3081
3082 switch (spec.type) {
3083 case FORMAT_TYPE_NONE:
3084 case FORMAT_TYPE_PERCENT_CHAR:
3085 break;
3086 case FORMAT_TYPE_INVALID:
3087 goto out;
3088
3089 case FORMAT_TYPE_WIDTH:
3090 case FORMAT_TYPE_PRECISION:
3091 width = (int)save_arg(int);
3092 /* Pointers may require the width */
3093 if (*fmt == 'p')
3094 set_field_width(&spec, width);
3095 break;
3096
3097 case FORMAT_TYPE_CHAR:
3098 save_arg(char);
3099 break;
3100
3101 case FORMAT_TYPE_STR: {
3102 const char *save_str = va_arg(args, char *);
3103 const char *err_msg;
3104 size_t len;
3105
3106 err_msg = check_pointer_msg(save_str);
3107 if (err_msg)
3108 save_str = err_msg;
3109
3110 len = strlen(save_str) + 1;
3111 if (str + len < end)
3112 memcpy(str, save_str, len);
3113 str += len;
3114 break;
3115 }
3116
3117 case FORMAT_TYPE_PTR:
3118 /* Dereferenced pointers must be done now */
3119 switch (*fmt) {
3120 /* Dereference of functions is still OK */
3121 case 'S':
3122 case 's':
3123 case 'x':
3124 case 'K':
3125 case 'e':
3126 save_arg(void *);
3127 break;
3128 default:
3129 if (!isalnum(*fmt)) {
3130 save_arg(void *);
3131 break;
3132 }
3133 str = pointer(fmt, str, end, va_arg(args, void *),
3134 spec);
3135 if (str + 1 < end)
3136 *str++ = '\0';
3137 else
3138 end[-1] = '\0'; /* Must be nul terminated */
3139 }
3140 /* skip all alphanumeric pointer suffixes */
3141 while (isalnum(*fmt))
3142 fmt++;
3143 break;
3144
3145 default:
3146 switch (spec.type) {
3147
3148 case FORMAT_TYPE_LONG_LONG:
3149 save_arg(long long);
3150 break;
3151 case FORMAT_TYPE_ULONG:
3152 case FORMAT_TYPE_LONG:
3153 save_arg(unsigned long);
3154 break;
3155 case FORMAT_TYPE_SIZE_T:
3156 save_arg(size_t);
3157 break;
3158 case FORMAT_TYPE_PTRDIFF:
3159 save_arg(ptrdiff_t);
3160 break;
3161 case FORMAT_TYPE_UBYTE:
3162 case FORMAT_TYPE_BYTE:
3163 save_arg(char);
3164 break;
3165 case FORMAT_TYPE_USHORT:
3166 case FORMAT_TYPE_SHORT:
3167 save_arg(short);
3168 break;
3169 default:
3170 save_arg(int);
3171 }
3172 }
3173 }
3174
3175 out:
3176 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3177 #undef save_arg
3178 }
3179 EXPORT_SYMBOL_GPL(vbin_printf);
3180
3181 /**
3182 * bstr_printf - Format a string from binary arguments and place it in a buffer
3183 * @buf: The buffer to place the result into
3184 * @size: The size of the buffer, including the trailing null space
3185 * @fmt: The format string to use
3186 * @bin_buf: Binary arguments for the format string
3187 *
3188 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3189 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3190 * a binary buffer that generated by vbin_printf.
3191 *
3192 * The format follows C99 vsnprintf, but has some extensions:
3193 * see vsnprintf comment for details.
3194 *
3195 * The return value is the number of characters which would
3196 * be generated for the given input, excluding the trailing
3197 * '\0', as per ISO C99. If you want to have the exact
3198 * number of characters written into @buf as return value
3199 * (not including the trailing '\0'), use vscnprintf(). If the
3200 * return is greater than or equal to @size, the resulting
3201 * string is truncated.
3202 */
bstr_printf(char * buf,size_t size,const char * fmt,const u32 * bin_buf)3203 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3204 {
3205 struct printf_spec spec = {0};
3206 char *str, *end;
3207 const char *args = (const char *)bin_buf;
3208
3209 if (WARN_ON_ONCE(size > INT_MAX))
3210 return 0;
3211
3212 str = buf;
3213 end = buf + size;
3214
3215 #define get_arg(type) \
3216 ({ \
3217 typeof(type) value; \
3218 if (sizeof(type) == 8) { \
3219 args = PTR_ALIGN(args, sizeof(u32)); \
3220 *(u32 *)&value = *(u32 *)args; \
3221 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3222 } else { \
3223 args = PTR_ALIGN(args, sizeof(type)); \
3224 value = *(typeof(type) *)args; \
3225 } \
3226 args += sizeof(type); \
3227 value; \
3228 })
3229
3230 /* Make sure end is always >= buf */
3231 if (end < buf) {
3232 end = ((void *)-1);
3233 size = end - buf;
3234 }
3235
3236 while (*fmt) {
3237 const char *old_fmt = fmt;
3238 int read = format_decode(fmt, &spec);
3239
3240 fmt += read;
3241
3242 switch (spec.type) {
3243 case FORMAT_TYPE_NONE: {
3244 int copy = read;
3245 if (str < end) {
3246 if (copy > end - str)
3247 copy = end - str;
3248 memcpy(str, old_fmt, copy);
3249 }
3250 str += read;
3251 break;
3252 }
3253
3254 case FORMAT_TYPE_WIDTH:
3255 set_field_width(&spec, get_arg(int));
3256 break;
3257
3258 case FORMAT_TYPE_PRECISION:
3259 set_precision(&spec, get_arg(int));
3260 break;
3261
3262 case FORMAT_TYPE_CHAR: {
3263 char c;
3264
3265 if (!(spec.flags & LEFT)) {
3266 while (--spec.field_width > 0) {
3267 if (str < end)
3268 *str = ' ';
3269 ++str;
3270 }
3271 }
3272 c = (unsigned char) get_arg(char);
3273 if (str < end)
3274 *str = c;
3275 ++str;
3276 while (--spec.field_width > 0) {
3277 if (str < end)
3278 *str = ' ';
3279 ++str;
3280 }
3281 break;
3282 }
3283
3284 case FORMAT_TYPE_STR: {
3285 const char *str_arg = args;
3286 args += strlen(str_arg) + 1;
3287 str = string(str, end, (char *)str_arg, spec);
3288 break;
3289 }
3290
3291 case FORMAT_TYPE_PTR: {
3292 bool process = false;
3293 int copy, len;
3294 /* Non function dereferences were already done */
3295 switch (*fmt) {
3296 case 'S':
3297 case 's':
3298 case 'x':
3299 case 'K':
3300 case 'e':
3301 process = true;
3302 break;
3303 default:
3304 if (!isalnum(*fmt)) {
3305 process = true;
3306 break;
3307 }
3308 /* Pointer dereference was already processed */
3309 if (str < end) {
3310 len = copy = strlen(args);
3311 if (copy > end - str)
3312 copy = end - str;
3313 memcpy(str, args, copy);
3314 str += len;
3315 args += len + 1;
3316 }
3317 }
3318 if (process)
3319 str = pointer(fmt, str, end, get_arg(void *), spec);
3320
3321 while (isalnum(*fmt))
3322 fmt++;
3323 break;
3324 }
3325
3326 case FORMAT_TYPE_PERCENT_CHAR:
3327 if (str < end)
3328 *str = '%';
3329 ++str;
3330 break;
3331
3332 case FORMAT_TYPE_INVALID:
3333 goto out;
3334
3335 default: {
3336 unsigned long long num;
3337
3338 switch (spec.type) {
3339
3340 case FORMAT_TYPE_LONG_LONG:
3341 num = get_arg(long long);
3342 break;
3343 case FORMAT_TYPE_ULONG:
3344 case FORMAT_TYPE_LONG:
3345 num = get_arg(unsigned long);
3346 break;
3347 case FORMAT_TYPE_SIZE_T:
3348 num = get_arg(size_t);
3349 break;
3350 case FORMAT_TYPE_PTRDIFF:
3351 num = get_arg(ptrdiff_t);
3352 break;
3353 case FORMAT_TYPE_UBYTE:
3354 num = get_arg(unsigned char);
3355 break;
3356 case FORMAT_TYPE_BYTE:
3357 num = get_arg(signed char);
3358 break;
3359 case FORMAT_TYPE_USHORT:
3360 num = get_arg(unsigned short);
3361 break;
3362 case FORMAT_TYPE_SHORT:
3363 num = get_arg(short);
3364 break;
3365 case FORMAT_TYPE_UINT:
3366 num = get_arg(unsigned int);
3367 break;
3368 default:
3369 num = get_arg(int);
3370 }
3371
3372 str = number(str, end, num, spec);
3373 } /* default: */
3374 } /* switch(spec.type) */
3375 } /* while(*fmt) */
3376
3377 out:
3378 if (size > 0) {
3379 if (str < end)
3380 *str = '\0';
3381 else
3382 end[-1] = '\0';
3383 }
3384
3385 #undef get_arg
3386
3387 /* the trailing null byte doesn't count towards the total */
3388 return str - buf;
3389 }
3390 EXPORT_SYMBOL_GPL(bstr_printf);
3391
3392 /**
3393 * bprintf - Parse a format string and place args' binary value in a buffer
3394 * @bin_buf: The buffer to place args' binary value
3395 * @size: The size of the buffer(by words(32bits), not characters)
3396 * @fmt: The format string to use
3397 * @...: Arguments for the format string
3398 *
3399 * The function returns the number of words(u32) written
3400 * into @bin_buf.
3401 */
bprintf(u32 * bin_buf,size_t size,const char * fmt,...)3402 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3403 {
3404 va_list args;
3405 int ret;
3406
3407 va_start(args, fmt);
3408 ret = vbin_printf(bin_buf, size, fmt, args);
3409 va_end(args);
3410
3411 return ret;
3412 }
3413 EXPORT_SYMBOL_GPL(bprintf);
3414
3415 #endif /* CONFIG_BINARY_PRINTF */
3416
3417 /**
3418 * vsscanf - Unformat a buffer into a list of arguments
3419 * @buf: input buffer
3420 * @fmt: format of buffer
3421 * @args: arguments
3422 */
vsscanf(const char * buf,const char * fmt,va_list args)3423 int vsscanf(const char *buf, const char *fmt, va_list args)
3424 {
3425 const char *str = buf;
3426 char *next;
3427 char digit;
3428 int num = 0;
3429 u8 qualifier;
3430 unsigned int base;
3431 union {
3432 long long s;
3433 unsigned long long u;
3434 } val;
3435 s16 field_width;
3436 bool is_sign;
3437
3438 while (*fmt) {
3439 /* skip any white space in format */
3440 /* white space in format matches any amount of
3441 * white space, including none, in the input.
3442 */
3443 if (isspace(*fmt)) {
3444 fmt = skip_spaces(++fmt);
3445 str = skip_spaces(str);
3446 }
3447
3448 /* anything that is not a conversion must match exactly */
3449 if (*fmt != '%' && *fmt) {
3450 if (*fmt++ != *str++)
3451 break;
3452 continue;
3453 }
3454
3455 if (!*fmt)
3456 break;
3457 ++fmt;
3458
3459 /* skip this conversion.
3460 * advance both strings to next white space
3461 */
3462 if (*fmt == '*') {
3463 if (!*str)
3464 break;
3465 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3466 /* '%*[' not yet supported, invalid format */
3467 if (*fmt == '[')
3468 return num;
3469 fmt++;
3470 }
3471 while (!isspace(*str) && *str)
3472 str++;
3473 continue;
3474 }
3475
3476 /* get field width */
3477 field_width = -1;
3478 if (isdigit(*fmt)) {
3479 field_width = skip_atoi(&fmt);
3480 if (field_width <= 0)
3481 break;
3482 }
3483
3484 /* get conversion qualifier */
3485 qualifier = -1;
3486 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3487 *fmt == 'z') {
3488 qualifier = *fmt++;
3489 if (unlikely(qualifier == *fmt)) {
3490 if (qualifier == 'h') {
3491 qualifier = 'H';
3492 fmt++;
3493 } else if (qualifier == 'l') {
3494 qualifier = 'L';
3495 fmt++;
3496 }
3497 }
3498 }
3499
3500 if (!*fmt)
3501 break;
3502
3503 if (*fmt == 'n') {
3504 /* return number of characters read so far */
3505 *va_arg(args, int *) = str - buf;
3506 ++fmt;
3507 continue;
3508 }
3509
3510 if (!*str)
3511 break;
3512
3513 base = 10;
3514 is_sign = false;
3515
3516 switch (*fmt++) {
3517 case 'c':
3518 {
3519 char *s = (char *)va_arg(args, char*);
3520 if (field_width == -1)
3521 field_width = 1;
3522 do {
3523 *s++ = *str++;
3524 } while (--field_width > 0 && *str);
3525 num++;
3526 }
3527 continue;
3528 case 's':
3529 {
3530 char *s = (char *)va_arg(args, char *);
3531 if (field_width == -1)
3532 field_width = SHRT_MAX;
3533 /* first, skip leading white space in buffer */
3534 str = skip_spaces(str);
3535
3536 /* now copy until next white space */
3537 while (*str && !isspace(*str) && field_width--)
3538 *s++ = *str++;
3539 *s = '\0';
3540 num++;
3541 }
3542 continue;
3543 /*
3544 * Warning: This implementation of the '[' conversion specifier
3545 * deviates from its glibc counterpart in the following ways:
3546 * (1) It does NOT support ranges i.e. '-' is NOT a special
3547 * character
3548 * (2) It cannot match the closing bracket ']' itself
3549 * (3) A field width is required
3550 * (4) '%*[' (discard matching input) is currently not supported
3551 *
3552 * Example usage:
3553 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3554 * buf1, buf2, buf3);
3555 * if (ret < 3)
3556 * // etc..
3557 */
3558 case '[':
3559 {
3560 char *s = (char *)va_arg(args, char *);
3561 DECLARE_BITMAP(set, 256) = {0};
3562 unsigned int len = 0;
3563 bool negate = (*fmt == '^');
3564
3565 /* field width is required */
3566 if (field_width == -1)
3567 return num;
3568
3569 if (negate)
3570 ++fmt;
3571
3572 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3573 set_bit((u8)*fmt, set);
3574
3575 /* no ']' or no character set found */
3576 if (!*fmt || !len)
3577 return num;
3578 ++fmt;
3579
3580 if (negate) {
3581 bitmap_complement(set, set, 256);
3582 /* exclude null '\0' byte */
3583 clear_bit(0, set);
3584 }
3585
3586 /* match must be non-empty */
3587 if (!test_bit((u8)*str, set))
3588 return num;
3589
3590 while (test_bit((u8)*str, set) && field_width--)
3591 *s++ = *str++;
3592 *s = '\0';
3593 ++num;
3594 }
3595 continue;
3596 case 'o':
3597 base = 8;
3598 break;
3599 case 'x':
3600 case 'X':
3601 base = 16;
3602 break;
3603 case 'i':
3604 base = 0;
3605 fallthrough;
3606 case 'd':
3607 is_sign = true;
3608 fallthrough;
3609 case 'u':
3610 break;
3611 case '%':
3612 /* looking for '%' in str */
3613 if (*str++ != '%')
3614 return num;
3615 continue;
3616 default:
3617 /* invalid format; stop here */
3618 return num;
3619 }
3620
3621 /* have some sort of integer conversion.
3622 * first, skip white space in buffer.
3623 */
3624 str = skip_spaces(str);
3625
3626 digit = *str;
3627 if (is_sign && digit == '-') {
3628 if (field_width == 1)
3629 break;
3630
3631 digit = *(str + 1);
3632 }
3633
3634 if (!digit
3635 || (base == 16 && !isxdigit(digit))
3636 || (base == 10 && !isdigit(digit))
3637 || (base == 8 && (!isdigit(digit) || digit > '7'))
3638 || (base == 0 && !isdigit(digit)))
3639 break;
3640
3641 if (is_sign)
3642 val.s = simple_strntoll(str,
3643 field_width >= 0 ? field_width : INT_MAX,
3644 &next, base);
3645 else
3646 val.u = simple_strntoull(str,
3647 field_width >= 0 ? field_width : INT_MAX,
3648 &next, base);
3649
3650 switch (qualifier) {
3651 case 'H': /* that's 'hh' in format */
3652 if (is_sign)
3653 *va_arg(args, signed char *) = val.s;
3654 else
3655 *va_arg(args, unsigned char *) = val.u;
3656 break;
3657 case 'h':
3658 if (is_sign)
3659 *va_arg(args, short *) = val.s;
3660 else
3661 *va_arg(args, unsigned short *) = val.u;
3662 break;
3663 case 'l':
3664 if (is_sign)
3665 *va_arg(args, long *) = val.s;
3666 else
3667 *va_arg(args, unsigned long *) = val.u;
3668 break;
3669 case 'L':
3670 if (is_sign)
3671 *va_arg(args, long long *) = val.s;
3672 else
3673 *va_arg(args, unsigned long long *) = val.u;
3674 break;
3675 case 'z':
3676 *va_arg(args, size_t *) = val.u;
3677 break;
3678 default:
3679 if (is_sign)
3680 *va_arg(args, int *) = val.s;
3681 else
3682 *va_arg(args, unsigned int *) = val.u;
3683 break;
3684 }
3685 num++;
3686
3687 if (!next)
3688 break;
3689 str = next;
3690 }
3691
3692 return num;
3693 }
3694 EXPORT_SYMBOL(vsscanf);
3695
3696 /**
3697 * sscanf - Unformat a buffer into a list of arguments
3698 * @buf: input buffer
3699 * @fmt: formatting of buffer
3700 * @...: resulting arguments
3701 */
sscanf(const char * buf,const char * fmt,...)3702 int sscanf(const char *buf, const char *fmt, ...)
3703 {
3704 va_list args;
3705 int i;
3706
3707 va_start(args, fmt);
3708 i = vsscanf(buf, fmt, args);
3709 va_end(args);
3710
3711 return i;
3712 }
3713 EXPORT_SYMBOL(sscanf);
3714