projects/linux·blob v4.16-rc2 · refs

3186 lines · 73.9 KiB

1/*
2 * linux/lib/vsprintf.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8/*
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
10 */
11
12/*
13 * Fri Jul 13 2001 Crutcher Dunnavant <[email protected]>
14 * - changed to provide snprintf and vsnprintf functions
15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <[email protected]>
16 * - scnprintf and vscnprintf
17 */
18
19#include <stdarg.h>
20#include <linux/clk.h>
21#include <linux/clk-provider.h>
22#include <linux/module.h> /* for KSYM_SYMBOL_LEN */
23#include <linux/types.h>
24#include <linux/string.h>
25#include <linux/ctype.h>
26#include <linux/kernel.h>
27#include <linux/kallsyms.h>
28#include <linux/math64.h>
29#include <linux/uaccess.h>
30#include <linux/ioport.h>
31#include <linux/dcache.h>
32#include <linux/cred.h>
33#include <linux/uuid.h>
34#include <linux/of.h>
35#include <net/addrconf.h>
36#include <linux/siphash.h>
37#include <linux/compiler.h>
38#ifdef CONFIG_BLOCK
39#include <linux/blkdev.h>
40#endif
41
42#include "../mm/internal.h" /* For the trace_print_flags arrays */
43
44#include <asm/page.h> /* for PAGE_SIZE */
45#include <asm/byteorder.h> /* cpu_to_le16 */
46
47#include <linux/string_helpers.h>
48#include "kstrtox.h"
49
50/**
51 * simple_strtoull - convert a string to an unsigned long long
52 * @cp: The start of the string
53 * @endp: A pointer to the end of the parsed string will be placed here
54 * @base: The number base to use
55 *
56 * This function is obsolete. Please use kstrtoull instead.
57 */
58unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
59{
60 unsigned long long result;
61 unsigned int rv;
62
63 cp = _parse_integer_fixup_radix(cp, &base);
64 rv = _parse_integer(cp, base, &result);
65 /* FIXME */
66 cp += (rv & ~KSTRTOX_OVERFLOW);
67
68 if (endp)
69 *endp = (char *)cp;
70
71 return result;
72}
73EXPORT_SYMBOL(simple_strtoull);
74
75/**
76 * simple_strtoul - convert a string to an unsigned long
77 * @cp: The start of the string
78 * @endp: A pointer to the end of the parsed string will be placed here
79 * @base: The number base to use
80 *
81 * This function is obsolete. Please use kstrtoul instead.
82 */
83unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
84{
85 return simple_strtoull(cp, endp, base);
86}
87EXPORT_SYMBOL(simple_strtoul);
88
89/**
90 * simple_strtol - convert a string to a signed long
91 * @cp: The start of the string
92 * @endp: A pointer to the end of the parsed string will be placed here
93 * @base: The number base to use
94 *
95 * This function is obsolete. Please use kstrtol instead.
96 */
97long simple_strtol(const char *cp, char **endp, unsigned int base)
98{
99 if (*cp == '-')
100 return -simple_strtoul(cp + 1, endp, base);
101
102 return simple_strtoul(cp, endp, base);
103}
104EXPORT_SYMBOL(simple_strtol);
105
106/**
107 * simple_strtoll - convert a string to a signed long long
108 * @cp: The start of the string
109 * @endp: A pointer to the end of the parsed string will be placed here
110 * @base: The number base to use
111 *
112 * This function is obsolete. Please use kstrtoll instead.
113 */
114long long simple_strtoll(const char *cp, char **endp, unsigned int base)
115{
116 if (*cp == '-')
117 return -simple_strtoull(cp + 1, endp, base);
118
119 return simple_strtoull(cp, endp, base);
120}
121EXPORT_SYMBOL(simple_strtoll);
122
123static noinline_for_stack
124int skip_atoi(const char **s)
125{
126 int i = 0;
127
128 do {
129 i = i*10 + *((*s)++) - '0';
130 } while (isdigit(**s));
131
132 return i;
133}
134
135/*
136 * Decimal conversion is by far the most typical, and is used for
137 * /proc and /sys data. This directly impacts e.g. top performance
138 * with many processes running. We optimize it for speed by emitting
139 * two characters at a time, using a 200 byte lookup table. This
140 * roughly halves the number of multiplications compared to computing
141 * the digits one at a time. Implementation strongly inspired by the
142 * previous version, which in turn used ideas described at
143 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
144 * from the author, Douglas W. Jones).
145 *
146 * It turns out there is precisely one 26 bit fixed-point
147 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
148 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
149 * range happens to be somewhat larger (x <= 1073741898), but that's
150 * irrelevant for our purpose.
151 *
152 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
153 * need a 32x32->64 bit multiply, so we simply use the same constant.
154 *
155 * For dividing a number in the range [100, 10^4-1] by 100, there are
156 * several options. The simplest is (x * 0x147b) >> 19, which is valid
157 * for all x <= 43698.
158 */
159
160static const u16 decpair[100] = {
161#define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
162 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
163 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
164 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
165 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
166 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
167 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
168 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
169 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
170 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
171 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
172#undef _
173};
174
175/*
176 * This will print a single '0' even if r == 0, since we would
177 * immediately jump to out_r where two 0s would be written but only
178 * one of them accounted for in buf. This is needed by ip4_string
179 * below. All other callers pass a non-zero value of r.
180*/
181static noinline_for_stack
182char *put_dec_trunc8(char *buf, unsigned r)
183{
184 unsigned q;
185
186 /* 1 <= r < 10^8 */
187 if (r < 100)
188 goto out_r;
189
190 /* 100 <= r < 10^8 */
191 q = (r * (u64)0x28f5c29) >> 32;
192 *((u16 *)buf) = decpair[r - 100*q];
193 buf += 2;
194
195 /* 1 <= q < 10^6 */
196 if (q < 100)
197 goto out_q;
198
199 /* 100 <= q < 10^6 */
200 r = (q * (u64)0x28f5c29) >> 32;
201 *((u16 *)buf) = decpair[q - 100*r];
202 buf += 2;
203
204 /* 1 <= r < 10^4 */
205 if (r < 100)
206 goto out_r;
207
208 /* 100 <= r < 10^4 */
209 q = (r * 0x147b) >> 19;
210 *((u16 *)buf) = decpair[r - 100*q];
211 buf += 2;
212out_q:
213 /* 1 <= q < 100 */
214 r = q;
215out_r:
216 /* 1 <= r < 100 */
217 *((u16 *)buf) = decpair[r];
218 buf += r < 10 ? 1 : 2;
219 return buf;
220}
221
222#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
223static noinline_for_stack
224char *put_dec_full8(char *buf, unsigned r)
225{
226 unsigned q;
227
228 /* 0 <= r < 10^8 */
229 q = (r * (u64)0x28f5c29) >> 32;
230 *((u16 *)buf) = decpair[r - 100*q];
231 buf += 2;
232
233 /* 0 <= q < 10^6 */
234 r = (q * (u64)0x28f5c29) >> 32;
235 *((u16 *)buf) = decpair[q - 100*r];
236 buf += 2;
237
238 /* 0 <= r < 10^4 */
239 q = (r * 0x147b) >> 19;
240 *((u16 *)buf) = decpair[r - 100*q];
241 buf += 2;
242
243 /* 0 <= q < 100 */
244 *((u16 *)buf) = decpair[q];
245 buf += 2;
246 return buf;
247}
248
249static noinline_for_stack
250char *put_dec(char *buf, unsigned long long n)
251{
252 if (n >= 100*1000*1000)
253 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
254 /* 1 <= n <= 1.6e11 */
255 if (n >= 100*1000*1000)
256 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
257 /* 1 <= n < 1e8 */
258 return put_dec_trunc8(buf, n);
259}
260
261#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
262
263static void
264put_dec_full4(char *buf, unsigned r)
265{
266 unsigned q;
267
268 /* 0 <= r < 10^4 */
269 q = (r * 0x147b) >> 19;
270 *((u16 *)buf) = decpair[r - 100*q];
271 buf += 2;
272 /* 0 <= q < 100 */
273 *((u16 *)buf) = decpair[q];
274}
275
276/*
277 * Call put_dec_full4 on x % 10000, return x / 10000.
278 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
279 * holds for all x < 1,128,869,999. The largest value this
280 * helper will ever be asked to convert is 1,125,520,955.
281 * (second call in the put_dec code, assuming n is all-ones).
282 */
283static noinline_for_stack
284unsigned put_dec_helper4(char *buf, unsigned x)
285{
286 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
287
288 put_dec_full4(buf, x - q * 10000);
289 return q;
290}
291
292/* Based on code by Douglas W. Jones found at
293 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
294 * (with permission from the author).
295 * Performs no 64-bit division and hence should be fast on 32-bit machines.
296 */
297static
298char *put_dec(char *buf, unsigned long long n)
299{
300 uint32_t d3, d2, d1, q, h;
301
302 if (n < 100*1000*1000)
303 return put_dec_trunc8(buf, n);
304
305 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
306 h = (n >> 32);
307 d2 = (h ) & 0xffff;
308 d3 = (h >> 16); /* implicit "& 0xffff" */
309
310 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
311 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
312 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
313 q = put_dec_helper4(buf, q);
314
315 q += 7671 * d3 + 9496 * d2 + 6 * d1;
316 q = put_dec_helper4(buf+4, q);
317
318 q += 4749 * d3 + 42 * d2;
319 q = put_dec_helper4(buf+8, q);
320
321 q += 281 * d3;
322 buf += 12;
323 if (q)
324 buf = put_dec_trunc8(buf, q);
325 else while (buf[-1] == '0')
326 --buf;
327
328 return buf;
329}
330
331#endif
332
333/*
334 * Convert passed number to decimal string.
335 * Returns the length of string. On buffer overflow, returns 0.
336 *
337 * If speed is not important, use snprintf(). It's easy to read the code.
338 */
339int num_to_str(char *buf, int size, unsigned long long num)
340{
341 /* put_dec requires 2-byte alignment of the buffer. */
342 char tmp[sizeof(num) * 3] __aligned(2);
343 int idx, len;
344
345 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
346 if (num <= 9) {
347 tmp[0] = '0' + num;
348 len = 1;
349 } else {
350 len = put_dec(tmp, num) - tmp;
351 }
352
353 if (len > size)
354 return 0;
355 for (idx = 0; idx < len; ++idx)
356 buf[idx] = tmp[len - idx - 1];
357 return len;
358}
359
360#define SIGN 1 /* unsigned/signed, must be 1 */
361#define LEFT 2 /* left justified */
362#define PLUS 4 /* show plus */
363#define SPACE 8 /* space if plus */
364#define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
365#define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
366#define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
367
368enum format_type {
369 FORMAT_TYPE_NONE, /* Just a string part */
370 FORMAT_TYPE_WIDTH,
371 FORMAT_TYPE_PRECISION,
372 FORMAT_TYPE_CHAR,
373 FORMAT_TYPE_STR,
374 FORMAT_TYPE_PTR,
375 FORMAT_TYPE_PERCENT_CHAR,
376 FORMAT_TYPE_INVALID,
377 FORMAT_TYPE_LONG_LONG,
378 FORMAT_TYPE_ULONG,
379 FORMAT_TYPE_LONG,
380 FORMAT_TYPE_UBYTE,
381 FORMAT_TYPE_BYTE,
382 FORMAT_TYPE_USHORT,
383 FORMAT_TYPE_SHORT,
384 FORMAT_TYPE_UINT,
385 FORMAT_TYPE_INT,
386 FORMAT_TYPE_SIZE_T,
387 FORMAT_TYPE_PTRDIFF
388};
389
390struct printf_spec {
391 unsigned int type:8; /* format_type enum */
392 signed int field_width:24; /* width of output field */
393 unsigned int flags:8; /* flags to number() */
394 unsigned int base:8; /* number base, 8, 10 or 16 only */
395 signed int precision:16; /* # of digits/chars */
396} __packed;
397#define FIELD_WIDTH_MAX ((1 << 23) - 1)
398#define PRECISION_MAX ((1 << 15) - 1)
399
400static noinline_for_stack
401char *number(char *buf, char *end, unsigned long long num,
402 struct printf_spec spec)
403{
404 /* put_dec requires 2-byte alignment of the buffer. */
405 char tmp[3 * sizeof(num)] __aligned(2);
406 char sign;
407 char locase;
408 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
409 int i;
410 bool is_zero = num == 0LL;
411 int field_width = spec.field_width;
412 int precision = spec.precision;
413
414 BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
415
416 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
417 * produces same digits or (maybe lowercased) letters */
418 locase = (spec.flags & SMALL);
419 if (spec.flags & LEFT)
420 spec.flags &= ~ZEROPAD;
421 sign = 0;
422 if (spec.flags & SIGN) {
423 if ((signed long long)num < 0) {
424 sign = '-';
425 num = -(signed long long)num;
426 field_width--;
427 } else if (spec.flags & PLUS) {
428 sign = '+';
429 field_width--;
430 } else if (spec.flags & SPACE) {
431 sign = ' ';
432 field_width--;
433 }
434 }
435 if (need_pfx) {
436 if (spec.base == 16)
437 field_width -= 2;
438 else if (!is_zero)
439 field_width--;
440 }
441
442 /* generate full string in tmp[], in reverse order */
443 i = 0;
444 if (num < spec.base)
445 tmp[i++] = hex_asc_upper[num] | locase;
446 else if (spec.base != 10) { /* 8 or 16 */
447 int mask = spec.base - 1;
448 int shift = 3;
449
450 if (spec.base == 16)
451 shift = 4;
452 do {
453 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
454 num >>= shift;
455 } while (num);
456 } else { /* base 10 */
457 i = put_dec(tmp, num) - tmp;
458 }
459
460 /* printing 100 using %2d gives "100", not "00" */
461 if (i > precision)
462 precision = i;
463 /* leading space padding */
464 field_width -= precision;
465 if (!(spec.flags & (ZEROPAD | LEFT))) {
466 while (--field_width >= 0) {
467 if (buf < end)
468 *buf = ' ';
469 ++buf;
470 }
471 }
472 /* sign */
473 if (sign) {
474 if (buf < end)
475 *buf = sign;
476 ++buf;
477 }
478 /* "0x" / "0" prefix */
479 if (need_pfx) {
480 if (spec.base == 16 || !is_zero) {
481 if (buf < end)
482 *buf = '0';
483 ++buf;
484 }
485 if (spec.base == 16) {
486 if (buf < end)
487 *buf = ('X' | locase);
488 ++buf;
489 }
490 }
491 /* zero or space padding */
492 if (!(spec.flags & LEFT)) {
493 char c = ' ' + (spec.flags & ZEROPAD);
494 BUILD_BUG_ON(' ' + ZEROPAD != '0');
495 while (--field_width >= 0) {
496 if (buf < end)
497 *buf = c;
498 ++buf;
499 }
500 }
501 /* hmm even more zero padding? */
502 while (i <= --precision) {
503 if (buf < end)
504 *buf = '0';
505 ++buf;
506 }
507 /* actual digits of result */
508 while (--i >= 0) {
509 if (buf < end)
510 *buf = tmp[i];
511 ++buf;
512 }
513 /* trailing space padding */
514 while (--field_width >= 0) {
515 if (buf < end)
516 *buf = ' ';
517 ++buf;
518 }
519
520 return buf;
521}
522
523static noinline_for_stack
524char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
525{
526 struct printf_spec spec;
527
528 spec.type = FORMAT_TYPE_PTR;
529 spec.field_width = 2 + 2 * size; /* 0x + hex */
530 spec.flags = SPECIAL | SMALL | ZEROPAD;
531 spec.base = 16;
532 spec.precision = -1;
533
534 return number(buf, end, num, spec);
535}
536
537static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
538{
539 size_t size;
540 if (buf >= end) /* nowhere to put anything */
541 return;
542 size = end - buf;
543 if (size <= spaces) {
544 memset(buf, ' ', size);
545 return;
546 }
547 if (len) {
548 if (len > size - spaces)
549 len = size - spaces;
550 memmove(buf + spaces, buf, len);
551 }
552 memset(buf, ' ', spaces);
553}
554
555/*
556 * Handle field width padding for a string.
557 * @buf: current buffer position
558 * @n: length of string
559 * @end: end of output buffer
560 * @spec: for field width and flags
561 * Returns: new buffer position after padding.
562 */
563static noinline_for_stack
564char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
565{
566 unsigned spaces;
567
568 if (likely(n >= spec.field_width))
569 return buf;
570 /* we want to pad the sucker */
571 spaces = spec.field_width - n;
572 if (!(spec.flags & LEFT)) {
573 move_right(buf - n, end, n, spaces);
574 return buf + spaces;
575 }
576 while (spaces--) {
577 if (buf < end)
578 *buf = ' ';
579 ++buf;
580 }
581 return buf;
582}
583
584static noinline_for_stack
585char *string(char *buf, char *end, const char *s, struct printf_spec spec)
586{
587 int len = 0;
588 size_t lim = spec.precision;
589
590 if ((unsigned long)s < PAGE_SIZE)
591 s = "(null)";
592
593 while (lim--) {
594 char c = *s++;
595 if (!c)
596 break;
597 if (buf < end)
598 *buf = c;
599 ++buf;
600 ++len;
601 }
602 return widen_string(buf, len, end, spec);
603}
604
605static noinline_for_stack
606char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
607 const char *fmt)
608{
609 const char *array[4], *s;
610 const struct dentry *p;
611 int depth;
612 int i, n;
613
614 switch (fmt[1]) {
615 case '2': case '3': case '4':
616 depth = fmt[1] - '0';
617 break;
618 default:
619 depth = 1;
620 }
621
622 rcu_read_lock();
623 for (i = 0; i < depth; i++, d = p) {
624 p = READ_ONCE(d->d_parent);
625 array[i] = READ_ONCE(d->d_name.name);
626 if (p == d) {
627 if (i)
628 array[i] = "";
629 i++;
630 break;
631 }
632 }
633 s = array[--i];
634 for (n = 0; n != spec.precision; n++, buf++) {
635 char c = *s++;
636 if (!c) {
637 if (!i)
638 break;
639 c = '/';
640 s = array[--i];
641 }
642 if (buf < end)
643 *buf = c;
644 }
645 rcu_read_unlock();
646 return widen_string(buf, n, end, spec);
647}
648
649#ifdef CONFIG_BLOCK
650static noinline_for_stack
651char *bdev_name(char *buf, char *end, struct block_device *bdev,
652 struct printf_spec spec, const char *fmt)
653{
654 struct gendisk *hd = bdev->bd_disk;
655
656 buf = string(buf, end, hd->disk_name, spec);
657 if (bdev->bd_part->partno) {
658 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
659 if (buf < end)
660 *buf = 'p';
661 buf++;
662 }
663 buf = number(buf, end, bdev->bd_part->partno, spec);
664 }
665 return buf;
666}
667#endif
668
669static noinline_for_stack
670char *symbol_string(char *buf, char *end, void *ptr,
671 struct printf_spec spec, const char *fmt)
672{
673 unsigned long value;
674#ifdef CONFIG_KALLSYMS
675 char sym[KSYM_SYMBOL_LEN];
676#endif
677
678 if (fmt[1] == 'R')
679 ptr = __builtin_extract_return_addr(ptr);
680 value = (unsigned long)ptr;
681
682#ifdef CONFIG_KALLSYMS
683 if (*fmt == 'B')
684 sprint_backtrace(sym, value);
685 else if (*fmt != 'f' && *fmt != 's')
686 sprint_symbol(sym, value);
687 else
688 sprint_symbol_no_offset(sym, value);
689
690 return string(buf, end, sym, spec);
691#else
692 return special_hex_number(buf, end, value, sizeof(void *));
693#endif
694}
695
696static noinline_for_stack
697char *resource_string(char *buf, char *end, struct resource *res,
698 struct printf_spec spec, const char *fmt)
699{
700#ifndef IO_RSRC_PRINTK_SIZE
701#define IO_RSRC_PRINTK_SIZE 6
702#endif
703
704#ifndef MEM_RSRC_PRINTK_SIZE
705#define MEM_RSRC_PRINTK_SIZE 10
706#endif
707 static const struct printf_spec io_spec = {
708 .base = 16,
709 .field_width = IO_RSRC_PRINTK_SIZE,
710 .precision = -1,
711 .flags = SPECIAL | SMALL | ZEROPAD,
712 };
713 static const struct printf_spec mem_spec = {
714 .base = 16,
715 .field_width = MEM_RSRC_PRINTK_SIZE,
716 .precision = -1,
717 .flags = SPECIAL | SMALL | ZEROPAD,
718 };
719 static const struct printf_spec bus_spec = {
720 .base = 16,
721 .field_width = 2,
722 .precision = -1,
723 .flags = SMALL | ZEROPAD,
724 };
725 static const struct printf_spec dec_spec = {
726 .base = 10,
727 .precision = -1,
728 .flags = 0,
729 };
730 static const struct printf_spec str_spec = {
731 .field_width = -1,
732 .precision = 10,
733 .flags = LEFT,
734 };
735 static const struct printf_spec flag_spec = {
736 .base = 16,
737 .precision = -1,
738 .flags = SPECIAL | SMALL,
739 };
740
741 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
742 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
743#define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
744#define FLAG_BUF_SIZE (2 * sizeof(res->flags))
745#define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
746#define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
747 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
748 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
749
750 char *p = sym, *pend = sym + sizeof(sym);
751 int decode = (fmt[0] == 'R') ? 1 : 0;
752 const struct printf_spec *specp;
753
754 *p++ = '[';
755 if (res->flags & IORESOURCE_IO) {
756 p = string(p, pend, "io ", str_spec);
757 specp = &io_spec;
758 } else if (res->flags & IORESOURCE_MEM) {
759 p = string(p, pend, "mem ", str_spec);
760 specp = &mem_spec;
761 } else if (res->flags & IORESOURCE_IRQ) {
762 p = string(p, pend, "irq ", str_spec);
763 specp = &dec_spec;
764 } else if (res->flags & IORESOURCE_DMA) {
765 p = string(p, pend, "dma ", str_spec);
766 specp = &dec_spec;
767 } else if (res->flags & IORESOURCE_BUS) {
768 p = string(p, pend, "bus ", str_spec);
769 specp = &bus_spec;
770 } else {
771 p = string(p, pend, "??? ", str_spec);
772 specp = &mem_spec;
773 decode = 0;
774 }
775 if (decode && res->flags & IORESOURCE_UNSET) {
776 p = string(p, pend, "size ", str_spec);
777 p = number(p, pend, resource_size(res), *specp);
778 } else {
779 p = number(p, pend, res->start, *specp);
780 if (res->start != res->end) {
781 *p++ = '-';
782 p = number(p, pend, res->end, *specp);
783 }
784 }
785 if (decode) {
786 if (res->flags & IORESOURCE_MEM_64)
787 p = string(p, pend, " 64bit", str_spec);
788 if (res->flags & IORESOURCE_PREFETCH)
789 p = string(p, pend, " pref", str_spec);
790 if (res->flags & IORESOURCE_WINDOW)
791 p = string(p, pend, " window", str_spec);
792 if (res->flags & IORESOURCE_DISABLED)
793 p = string(p, pend, " disabled", str_spec);
794 } else {
795 p = string(p, pend, " flags ", str_spec);
796 p = number(p, pend, res->flags, flag_spec);
797 }
798 *p++ = ']';
799 *p = '\0';
800
801 return string(buf, end, sym, spec);
802}
803
804static noinline_for_stack
805char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
806 const char *fmt)
807{
808 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
809 negative value, fallback to the default */
810 char separator;
811
812 if (spec.field_width == 0)
813 /* nothing to print */
814 return buf;
815
816 if (ZERO_OR_NULL_PTR(addr))
817 /* NULL pointer */
818 return string(buf, end, NULL, spec);
819
820 switch (fmt[1]) {
821 case 'C':
822 separator = ':';
823 break;
824 case 'D':
825 separator = '-';
826 break;
827 case 'N':
828 separator = 0;
829 break;
830 default:
831 separator = ' ';
832 break;
833 }
834
835 if (spec.field_width > 0)
836 len = min_t(int, spec.field_width, 64);
837
838 for (i = 0; i < len; ++i) {
839 if (buf < end)
840 *buf = hex_asc_hi(addr[i]);
841 ++buf;
842 if (buf < end)
843 *buf = hex_asc_lo(addr[i]);
844 ++buf;
845
846 if (separator && i != len - 1) {
847 if (buf < end)
848 *buf = separator;
849 ++buf;
850 }
851 }
852
853 return buf;
854}
855
856static noinline_for_stack
857char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
858 struct printf_spec spec, const char *fmt)
859{
860 const int CHUNKSZ = 32;
861 int nr_bits = max_t(int, spec.field_width, 0);
862 int i, chunksz;
863 bool first = true;
864
865 /* reused to print numbers */
866 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
867
868 chunksz = nr_bits & (CHUNKSZ - 1);
869 if (chunksz == 0)
870 chunksz = CHUNKSZ;
871
872 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
873 for (; i >= 0; i -= CHUNKSZ) {
874 u32 chunkmask, val;
875 int word, bit;
876
877 chunkmask = ((1ULL << chunksz) - 1);
878 word = i / BITS_PER_LONG;
879 bit = i % BITS_PER_LONG;
880 val = (bitmap[word] >> bit) & chunkmask;
881
882 if (!first) {
883 if (buf < end)
884 *buf = ',';
885 buf++;
886 }
887 first = false;
888
889 spec.field_width = DIV_ROUND_UP(chunksz, 4);
890 buf = number(buf, end, val, spec);
891
892 chunksz = CHUNKSZ;
893 }
894 return buf;
895}
896
897static noinline_for_stack
898char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
899 struct printf_spec spec, const char *fmt)
900{
901 int nr_bits = max_t(int, spec.field_width, 0);
902 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
903 int cur, rbot, rtop;
904 bool first = true;
905
906 /* reused to print numbers */
907 spec = (struct printf_spec){ .base = 10 };
908
909 rbot = cur = find_first_bit(bitmap, nr_bits);
910 while (cur < nr_bits) {
911 rtop = cur;
912 cur = find_next_bit(bitmap, nr_bits, cur + 1);
913 if (cur < nr_bits && cur <= rtop + 1)
914 continue;
915
916 if (!first) {
917 if (buf < end)
918 *buf = ',';
919 buf++;
920 }
921 first = false;
922
923 buf = number(buf, end, rbot, spec);
924 if (rbot < rtop) {
925 if (buf < end)
926 *buf = '-';
927 buf++;
928
929 buf = number(buf, end, rtop, spec);
930 }
931
932 rbot = cur;
933 }
934 return buf;
935}
936
937static noinline_for_stack
938char *mac_address_string(char *buf, char *end, u8 *addr,
939 struct printf_spec spec, const char *fmt)
940{
941 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
942 char *p = mac_addr;
943 int i;
944 char separator;
945 bool reversed = false;
946
947 switch (fmt[1]) {
948 case 'F':
949 separator = '-';
950 break;
951
952 case 'R':
953 reversed = true;
954 /* fall through */
955
956 default:
957 separator = ':';
958 break;
959 }
960
961 for (i = 0; i < 6; i++) {
962 if (reversed)
963 p = hex_byte_pack(p, addr[5 - i]);
964 else
965 p = hex_byte_pack(p, addr[i]);
966
967 if (fmt[0] == 'M' && i != 5)
968 *p++ = separator;
969 }
970 *p = '\0';
971
972 return string(buf, end, mac_addr, spec);
973}
974
975static noinline_for_stack
976char *ip4_string(char *p, const u8 *addr, const char *fmt)
977{
978 int i;
979 bool leading_zeros = (fmt[0] == 'i');
980 int index;
981 int step;
982
983 switch (fmt[2]) {
984 case 'h':
985#ifdef __BIG_ENDIAN
986 index = 0;
987 step = 1;
988#else
989 index = 3;
990 step = -1;
991#endif
992 break;
993 case 'l':
994 index = 3;
995 step = -1;
996 break;
997 case 'n':
998 case 'b':
999 default:
1000 index = 0;
1001 step = 1;
1002 break;
1003 }
1004 for (i = 0; i < 4; i++) {
1005 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1006 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1007 if (leading_zeros) {
1008 if (digits < 3)
1009 *p++ = '0';
1010 if (digits < 2)
1011 *p++ = '0';
1012 }
1013 /* reverse the digits in the quad */
1014 while (digits--)
1015 *p++ = temp[digits];
1016 if (i < 3)
1017 *p++ = '.';
1018 index += step;
1019 }
1020 *p = '\0';
1021
1022 return p;
1023}
1024
1025static noinline_for_stack
1026char *ip6_compressed_string(char *p, const char *addr)
1027{
1028 int i, j, range;
1029 unsigned char zerolength[8];
1030 int longest = 1;
1031 int colonpos = -1;
1032 u16 word;
1033 u8 hi, lo;
1034 bool needcolon = false;
1035 bool useIPv4;
1036 struct in6_addr in6;
1037
1038 memcpy(&in6, addr, sizeof(struct in6_addr));
1039
1040 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1041
1042 memset(zerolength, 0, sizeof(zerolength));
1043
1044 if (useIPv4)
1045 range = 6;
1046 else
1047 range = 8;
1048
1049 /* find position of longest 0 run */
1050 for (i = 0; i < range; i++) {
1051 for (j = i; j < range; j++) {
1052 if (in6.s6_addr16[j] != 0)
1053 break;
1054 zerolength[i]++;
1055 }
1056 }
1057 for (i = 0; i < range; i++) {
1058 if (zerolength[i] > longest) {
1059 longest = zerolength[i];
1060 colonpos = i;
1061 }
1062 }
1063 if (longest == 1) /* don't compress a single 0 */
1064 colonpos = -1;
1065
1066 /* emit address */
1067 for (i = 0; i < range; i++) {
1068 if (i == colonpos) {
1069 if (needcolon || i == 0)
1070 *p++ = ':';
1071 *p++ = ':';
1072 needcolon = false;
1073 i += longest - 1;
1074 continue;
1075 }
1076 if (needcolon) {
1077 *p++ = ':';
1078 needcolon = false;
1079 }
1080 /* hex u16 without leading 0s */
1081 word = ntohs(in6.s6_addr16[i]);
1082 hi = word >> 8;
1083 lo = word & 0xff;
1084 if (hi) {
1085 if (hi > 0x0f)
1086 p = hex_byte_pack(p, hi);
1087 else
1088 *p++ = hex_asc_lo(hi);
1089 p = hex_byte_pack(p, lo);
1090 }
1091 else if (lo > 0x0f)
1092 p = hex_byte_pack(p, lo);
1093 else
1094 *p++ = hex_asc_lo(lo);
1095 needcolon = true;
1096 }
1097
1098 if (useIPv4) {
1099 if (needcolon)
1100 *p++ = ':';
1101 p = ip4_string(p, &in6.s6_addr[12], "I4");
1102 }
1103 *p = '\0';
1104
1105 return p;
1106}
1107
1108static noinline_for_stack
1109char *ip6_string(char *p, const char *addr, const char *fmt)
1110{
1111 int i;
1112
1113 for (i = 0; i < 8; i++) {
1114 p = hex_byte_pack(p, *addr++);
1115 p = hex_byte_pack(p, *addr++);
1116 if (fmt[0] == 'I' && i != 7)
1117 *p++ = ':';
1118 }
1119 *p = '\0';
1120
1121 return p;
1122}
1123
1124static noinline_for_stack
1125char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1126 struct printf_spec spec, const char *fmt)
1127{
1128 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1129
1130 if (fmt[0] == 'I' && fmt[2] == 'c')
1131 ip6_compressed_string(ip6_addr, addr);
1132 else
1133 ip6_string(ip6_addr, addr, fmt);
1134
1135 return string(buf, end, ip6_addr, spec);
1136}
1137
1138static noinline_for_stack
1139char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1140 struct printf_spec spec, const char *fmt)
1141{
1142 char ip4_addr[sizeof("255.255.255.255")];
1143
1144 ip4_string(ip4_addr, addr, fmt);
1145
1146 return string(buf, end, ip4_addr, spec);
1147}
1148
1149static noinline_for_stack
1150char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1151 struct printf_spec spec, const char *fmt)
1152{
1153 bool have_p = false, have_s = false, have_f = false, have_c = false;
1154 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1155 sizeof(":12345") + sizeof("/123456789") +
1156 sizeof("%1234567890")];
1157 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1158 const u8 *addr = (const u8 *) &sa->sin6_addr;
1159 char fmt6[2] = { fmt[0], '6' };
1160 u8 off = 0;
1161
1162 fmt++;
1163 while (isalpha(*++fmt)) {
1164 switch (*fmt) {
1165 case 'p':
1166 have_p = true;
1167 break;
1168 case 'f':
1169 have_f = true;
1170 break;
1171 case 's':
1172 have_s = true;
1173 break;
1174 case 'c':
1175 have_c = true;
1176 break;
1177 }
1178 }
1179
1180 if (have_p || have_s || have_f) {
1181 *p = '[';
1182 off = 1;
1183 }
1184
1185 if (fmt6[0] == 'I' && have_c)
1186 p = ip6_compressed_string(ip6_addr + off, addr);
1187 else
1188 p = ip6_string(ip6_addr + off, addr, fmt6);
1189
1190 if (have_p || have_s || have_f)
1191 *p++ = ']';
1192
1193 if (have_p) {
1194 *p++ = ':';
1195 p = number(p, pend, ntohs(sa->sin6_port), spec);
1196 }
1197 if (have_f) {
1198 *p++ = '/';
1199 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1200 IPV6_FLOWINFO_MASK), spec);
1201 }
1202 if (have_s) {
1203 *p++ = '%';
1204 p = number(p, pend, sa->sin6_scope_id, spec);
1205 }
1206 *p = '\0';
1207
1208 return string(buf, end, ip6_addr, spec);
1209}
1210
1211static noinline_for_stack
1212char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1213 struct printf_spec spec, const char *fmt)
1214{
1215 bool have_p = false;
1216 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1217 char *pend = ip4_addr + sizeof(ip4_addr);
1218 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1219 char fmt4[3] = { fmt[0], '4', 0 };
1220
1221 fmt++;
1222 while (isalpha(*++fmt)) {
1223 switch (*fmt) {
1224 case 'p':
1225 have_p = true;
1226 break;
1227 case 'h':
1228 case 'l':
1229 case 'n':
1230 case 'b':
1231 fmt4[2] = *fmt;
1232 break;
1233 }
1234 }
1235
1236 p = ip4_string(ip4_addr, addr, fmt4);
1237 if (have_p) {
1238 *p++ = ':';
1239 p = number(p, pend, ntohs(sa->sin_port), spec);
1240 }
1241 *p = '\0';
1242
1243 return string(buf, end, ip4_addr, spec);
1244}
1245
1246static noinline_for_stack
1247char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1248 const char *fmt)
1249{
1250 bool found = true;
1251 int count = 1;
1252 unsigned int flags = 0;
1253 int len;
1254
1255 if (spec.field_width == 0)
1256 return buf; /* nothing to print */
1257
1258 if (ZERO_OR_NULL_PTR(addr))
1259 return string(buf, end, NULL, spec); /* NULL pointer */
1260
1261
1262 do {
1263 switch (fmt[count++]) {
1264 case 'a':
1265 flags |= ESCAPE_ANY;
1266 break;
1267 case 'c':
1268 flags |= ESCAPE_SPECIAL;
1269 break;
1270 case 'h':
1271 flags |= ESCAPE_HEX;
1272 break;
1273 case 'n':
1274 flags |= ESCAPE_NULL;
1275 break;
1276 case 'o':
1277 flags |= ESCAPE_OCTAL;
1278 break;
1279 case 'p':
1280 flags |= ESCAPE_NP;
1281 break;
1282 case 's':
1283 flags |= ESCAPE_SPACE;
1284 break;
1285 default:
1286 found = false;
1287 break;
1288 }
1289 } while (found);
1290
1291 if (!flags)
1292 flags = ESCAPE_ANY_NP;
1293
1294 len = spec.field_width < 0 ? 1 : spec.field_width;
1295
1296 /*
1297 * string_escape_mem() writes as many characters as it can to
1298 * the given buffer, and returns the total size of the output
1299 * had the buffer been big enough.
1300 */
1301 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1302
1303 return buf;
1304}
1305
1306static noinline_for_stack
1307char *uuid_string(char *buf, char *end, const u8 *addr,
1308 struct printf_spec spec, const char *fmt)
1309{
1310 char uuid[UUID_STRING_LEN + 1];
1311 char *p = uuid;
1312 int i;
1313 const u8 *index = uuid_index;
1314 bool uc = false;
1315
1316 switch (*(++fmt)) {
1317 case 'L':
1318 uc = true; /* fall-through */
1319 case 'l':
1320 index = guid_index;
1321 break;
1322 case 'B':
1323 uc = true;
1324 break;
1325 }
1326
1327 for (i = 0; i < 16; i++) {
1328 if (uc)
1329 p = hex_byte_pack_upper(p, addr[index[i]]);
1330 else
1331 p = hex_byte_pack(p, addr[index[i]]);
1332 switch (i) {
1333 case 3:
1334 case 5:
1335 case 7:
1336 case 9:
1337 *p++ = '-';
1338 break;
1339 }
1340 }
1341
1342 *p = 0;
1343
1344 return string(buf, end, uuid, spec);
1345}
1346
1347int kptr_restrict __read_mostly;
1348
1349static noinline_for_stack
1350char *restricted_pointer(char *buf, char *end, const void *ptr,
1351 struct printf_spec spec)
1352{
1353 spec.base = 16;
1354 spec.flags |= SMALL;
1355 if (spec.field_width == -1) {
1356 spec.field_width = 2 * sizeof(ptr);
1357 spec.flags |= ZEROPAD;
1358 }
1359
1360 switch (kptr_restrict) {
1361 case 0:
1362 /* Always print %pK values */
1363 break;
1364 case 1: {
1365 const struct cred *cred;
1366
1367 /*
1368 * kptr_restrict==1 cannot be used in IRQ context
1369 * because its test for CAP_SYSLOG would be meaningless.
1370 */
1371 if (in_irq() || in_serving_softirq() || in_nmi())
1372 return string(buf, end, "pK-error", spec);
1373
1374 /*
1375 * Only print the real pointer value if the current
1376 * process has CAP_SYSLOG and is running with the
1377 * same credentials it started with. This is because
1378 * access to files is checked at open() time, but %pK
1379 * checks permission at read() time. We don't want to
1380 * leak pointer values if a binary opens a file using
1381 * %pK and then elevates privileges before reading it.
1382 */
1383 cred = current_cred();
1384 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1385 !uid_eq(cred->euid, cred->uid) ||
1386 !gid_eq(cred->egid, cred->gid))
1387 ptr = NULL;
1388 break;
1389 }
1390 case 2:
1391 default:
1392 /* Always print 0's for %pK */
1393 ptr = NULL;
1394 break;
1395 }
1396
1397 return number(buf, end, (unsigned long)ptr, spec);
1398}
1399
1400static noinline_for_stack
1401char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1402{
1403 unsigned long long num;
1404 int size;
1405
1406 switch (fmt[1]) {
1407 case 'F':
1408 num = *(const netdev_features_t *)addr;
1409 size = sizeof(netdev_features_t);
1410 break;
1411 default:
1412 num = (unsigned long)addr;
1413 size = sizeof(unsigned long);
1414 break;
1415 }
1416
1417 return special_hex_number(buf, end, num, size);
1418}
1419
1420static noinline_for_stack
1421char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1422{
1423 unsigned long long num;
1424 int size;
1425
1426 switch (fmt[1]) {
1427 case 'd':
1428 num = *(const dma_addr_t *)addr;
1429 size = sizeof(dma_addr_t);
1430 break;
1431 case 'p':
1432 default:
1433 num = *(const phys_addr_t *)addr;
1434 size = sizeof(phys_addr_t);
1435 break;
1436 }
1437
1438 return special_hex_number(buf, end, num, size);
1439}
1440
1441static noinline_for_stack
1442char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1443 const char *fmt)
1444{
1445 if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1446 return string(buf, end, NULL, spec);
1447
1448 switch (fmt[1]) {
1449 case 'r':
1450 return number(buf, end, clk_get_rate(clk), spec);
1451
1452 case 'n':
1453 default:
1454#ifdef CONFIG_COMMON_CLK
1455 return string(buf, end, __clk_get_name(clk), spec);
1456#else
1457 return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1458#endif
1459 }
1460}
1461
1462static
1463char *format_flags(char *buf, char *end, unsigned long flags,
1464 const struct trace_print_flags *names)
1465{
1466 unsigned long mask;
1467 const struct printf_spec strspec = {
1468 .field_width = -1,
1469 .precision = -1,
1470 };
1471 const struct printf_spec numspec = {
1472 .flags = SPECIAL|SMALL,
1473 .field_width = -1,
1474 .precision = -1,
1475 .base = 16,
1476 };
1477
1478 for ( ; flags && names->name; names++) {
1479 mask = names->mask;
1480 if ((flags & mask) != mask)
1481 continue;
1482
1483 buf = string(buf, end, names->name, strspec);
1484
1485 flags &= ~mask;
1486 if (flags) {
1487 if (buf < end)
1488 *buf = '|';
1489 buf++;
1490 }
1491 }
1492
1493 if (flags)
1494 buf = number(buf, end, flags, numspec);
1495
1496 return buf;
1497}
1498
1499static noinline_for_stack
1500char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1501{
1502 unsigned long flags;
1503 const struct trace_print_flags *names;
1504
1505 switch (fmt[1]) {
1506 case 'p':
1507 flags = *(unsigned long *)flags_ptr;
1508 /* Remove zone id */
1509 flags &= (1UL << NR_PAGEFLAGS) - 1;
1510 names = pageflag_names;
1511 break;
1512 case 'v':
1513 flags = *(unsigned long *)flags_ptr;
1514 names = vmaflag_names;
1515 break;
1516 case 'g':
1517 flags = *(gfp_t *)flags_ptr;
1518 names = gfpflag_names;
1519 break;
1520 default:
1521 WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1522 return buf;
1523 }
1524
1525 return format_flags(buf, end, flags, names);
1526}
1527
1528static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1529{
1530 for ( ; np && depth; depth--)
1531 np = np->parent;
1532
1533 return kbasename(np->full_name);
1534}
1535
1536static noinline_for_stack
1537char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1538{
1539 int depth;
1540 const struct device_node *parent = np->parent;
1541 static const struct printf_spec strspec = {
1542 .field_width = -1,
1543 .precision = -1,
1544 };
1545
1546 /* special case for root node */
1547 if (!parent)
1548 return string(buf, end, "/", strspec);
1549
1550 for (depth = 0; parent->parent; depth++)
1551 parent = parent->parent;
1552
1553 for ( ; depth >= 0; depth--) {
1554 buf = string(buf, end, "/", strspec);
1555 buf = string(buf, end, device_node_name_for_depth(np, depth),
1556 strspec);
1557 }
1558 return buf;
1559}
1560
1561static noinline_for_stack
1562char *device_node_string(char *buf, char *end, struct device_node *dn,
1563 struct printf_spec spec, const char *fmt)
1564{
1565 char tbuf[sizeof("xxxx") + 1];
1566 const char *p;
1567 int ret;
1568 char *buf_start = buf;
1569 struct property *prop;
1570 bool has_mult, pass;
1571 static const struct printf_spec num_spec = {
1572 .flags = SMALL,
1573 .field_width = -1,
1574 .precision = -1,
1575 .base = 10,
1576 };
1577
1578 struct printf_spec str_spec = spec;
1579 str_spec.field_width = -1;
1580
1581 if (!IS_ENABLED(CONFIG_OF))
1582 return string(buf, end, "(!OF)", spec);
1583
1584 if ((unsigned long)dn < PAGE_SIZE)
1585 return string(buf, end, "(null)", spec);
1586
1587 /* simple case without anything any more format specifiers */
1588 fmt++;
1589 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1590 fmt = "f";
1591
1592 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1593 if (pass) {
1594 if (buf < end)
1595 *buf = ':';
1596 buf++;
1597 }
1598
1599 switch (*fmt) {
1600 case 'f': /* full_name */
1601 buf = device_node_gen_full_name(dn, buf, end);
1602 break;
1603 case 'n': /* name */
1604 buf = string(buf, end, dn->name, str_spec);
1605 break;
1606 case 'p': /* phandle */
1607 buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1608 break;
1609 case 'P': /* path-spec */
1610 p = kbasename(of_node_full_name(dn));
1611 if (!p[1])
1612 p = "/";
1613 buf = string(buf, end, p, str_spec);
1614 break;
1615 case 'F': /* flags */
1616 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1617 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1618 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1619 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1620 tbuf[4] = 0;
1621 buf = string(buf, end, tbuf, str_spec);
1622 break;
1623 case 'c': /* major compatible string */
1624 ret = of_property_read_string(dn, "compatible", &p);
1625 if (!ret)
1626 buf = string(buf, end, p, str_spec);
1627 break;
1628 case 'C': /* full compatible string */
1629 has_mult = false;
1630 of_property_for_each_string(dn, "compatible", prop, p) {
1631 if (has_mult)
1632 buf = string(buf, end, ",", str_spec);
1633 buf = string(buf, end, "\"", str_spec);
1634 buf = string(buf, end, p, str_spec);
1635 buf = string(buf, end, "\"", str_spec);
1636
1637 has_mult = true;
1638 }
1639 break;
1640 default:
1641 break;
1642 }
1643 }
1644
1645 return widen_string(buf, buf - buf_start, end, spec);
1646}
1647
1648static noinline_for_stack
1649char *pointer_string(char *buf, char *end, const void *ptr,
1650 struct printf_spec spec)
1651{
1652 spec.base = 16;
1653 spec.flags |= SMALL;
1654 if (spec.field_width == -1) {
1655 spec.field_width = 2 * sizeof(ptr);
1656 spec.flags |= ZEROPAD;
1657 }
1658
1659 return number(buf, end, (unsigned long int)ptr, spec);
1660}
1661
1662static bool have_filled_random_ptr_key __read_mostly;
1663static siphash_key_t ptr_key __read_mostly;
1664
1665static void fill_random_ptr_key(struct random_ready_callback *unused)
1666{
1667 get_random_bytes(&ptr_key, sizeof(ptr_key));
1668 /*
1669 * have_filled_random_ptr_key==true is dependent on get_random_bytes().
1670 * ptr_to_id() needs to see have_filled_random_ptr_key==true
1671 * after get_random_bytes() returns.
1672 */
1673 smp_mb();
1674 WRITE_ONCE(have_filled_random_ptr_key, true);
1675}
1676
1677static struct random_ready_callback random_ready = {
1678 .func = fill_random_ptr_key
1679};
1680
1681static int __init initialize_ptr_random(void)
1682{
1683 int ret = add_random_ready_callback(&random_ready);
1684
1685 if (!ret) {
1686 return 0;
1687 } else if (ret == -EALREADY) {
1688 fill_random_ptr_key(&random_ready);
1689 return 0;
1690 }
1691
1692 return ret;
1693}
1694early_initcall(initialize_ptr_random);
1695
1696/* Maps a pointer to a 32 bit unique identifier. */
1697static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
1698{
1699 unsigned long hashval;
1700 const int default_width = 2 * sizeof(ptr);
1701
1702 if (unlikely(!have_filled_random_ptr_key)) {
1703 spec.field_width = default_width;
1704 /* string length must be less than default_width */
1705 return string(buf, end, "(ptrval)", spec);
1706 }
1707
1708#ifdef CONFIG_64BIT
1709 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
1710 /*
1711 * Mask off the first 32 bits, this makes explicit that we have
1712 * modified the address (and 32 bits is plenty for a unique ID).
1713 */
1714 hashval = hashval & 0xffffffff;
1715#else
1716 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
1717#endif
1718
1719 spec.flags |= SMALL;
1720 if (spec.field_width == -1) {
1721 spec.field_width = default_width;
1722 spec.flags |= ZEROPAD;
1723 }
1724 spec.base = 16;
1725
1726 return number(buf, end, hashval, spec);
1727}
1728
1729/*
1730 * Show a '%p' thing. A kernel extension is that the '%p' is followed
1731 * by an extra set of alphanumeric characters that are extended format
1732 * specifiers.
1733 *
1734 * Please update scripts/checkpatch.pl when adding/removing conversion
1735 * characters. (Search for "check for vsprintf extension").
1736 *
1737 * Right now we handle:
1738 *
1739 * - 'F' For symbolic function descriptor pointers with offset
1740 * - 'f' For simple symbolic function names without offset
1741 * - 'S' For symbolic direct pointers with offset
1742 * - 's' For symbolic direct pointers without offset
1743 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1744 * - 'B' For backtraced symbolic direct pointers with offset
1745 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1746 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1747 * - 'b[l]' For a bitmap, the number of bits is determined by the field
1748 * width which must be explicitly specified either as part of the
1749 * format string '%32b[l]' or through '%*b[l]', [l] selects
1750 * range-list format instead of hex format
1751 * - 'M' For a 6-byte MAC address, it prints the address in the
1752 * usual colon-separated hex notation
1753 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1754 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1755 * with a dash-separated hex notation
1756 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1757 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1758 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1759 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
1760 * [S][pfs]
1761 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1762 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1763 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1764 * IPv6 omits the colons (01020304...0f)
1765 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1766 * [S][pfs]
1767 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1768 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1769 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1770 * - 'I[6S]c' for IPv6 addresses printed as specified by
1771 * http://tools.ietf.org/html/rfc5952
1772 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1773 * of the following flags (see string_escape_mem() for the
1774 * details):
1775 * a - ESCAPE_ANY
1776 * c - ESCAPE_SPECIAL
1777 * h - ESCAPE_HEX
1778 * n - ESCAPE_NULL
1779 * o - ESCAPE_OCTAL
1780 * p - ESCAPE_NP
1781 * s - ESCAPE_SPACE
1782 * By default ESCAPE_ANY_NP is used.
1783 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1784 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1785 * Options for %pU are:
1786 * b big endian lower case hex (default)
1787 * B big endian UPPER case hex
1788 * l little endian lower case hex
1789 * L little endian UPPER case hex
1790 * big endian output byte order is:
1791 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1792 * little endian output byte order is:
1793 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1794 * - 'V' For a struct va_format which contains a format string * and va_list *,
1795 * call vsnprintf(->format, *->va_list).
1796 * Implements a "recursive vsnprintf".
1797 * Do not use this feature without some mechanism to verify the
1798 * correctness of the format string and va_list arguments.
1799 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1800 * - 'NF' For a netdev_features_t
1801 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1802 * a certain separator (' ' by default):
1803 * C colon
1804 * D dash
1805 * N no separator
1806 * The maximum supported length is 64 bytes of the input. Consider
1807 * to use print_hex_dump() for the larger input.
1808 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1809 * (default assumed to be phys_addr_t, passed by reference)
1810 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1811 * - 'D[234]' Same as 'd' but for a struct file
1812 * - 'g' For block_device name (gendisk + partition number)
1813 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1814 * (legacy clock framework) of the clock
1815 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1816 * (legacy clock framework) of the clock
1817 * - 'Cr' For a clock, it prints the current rate of the clock
1818 * - 'G' For flags to be printed as a collection of symbolic strings that would
1819 * construct the specific value. Supported flags given by option:
1820 * p page flags (see struct page) given as pointer to unsigned long
1821 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1822 * v vma flags (VM_*) given as pointer to unsigned long
1823 * - 'O' For a kobject based struct. Must be one of the following:
1824 * - 'OF[fnpPcCF]' For a device tree object
1825 * Without any optional arguments prints the full_name
1826 * f device node full_name
1827 * n device node name
1828 * p device node phandle
1829 * P device node path spec (name + @unit)
1830 * F device node flags
1831 * c major compatible string
1832 * C full compatible string
1833 *
1834 * - 'x' For printing the address. Equivalent to "%lx".
1835 *
1836 * ** When making changes please also update:
1837 * Documentation/core-api/printk-formats.rst
1838 *
1839 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1840 * function pointers are really function descriptors, which contain a
1841 * pointer to the real address.
1842 *
1843 * Note: The default behaviour (unadorned %p) is to hash the address,
1844 * rendering it useful as a unique identifier.
1845 */
1846static noinline_for_stack
1847char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1848 struct printf_spec spec)
1849{
1850 const int default_width = 2 * sizeof(void *);
1851
1852 if (!ptr && *fmt != 'K') {
1853 /*
1854 * Print (null) with the same width as a pointer so it makes
1855 * tabular output look nice.
1856 */
1857 if (spec.field_width == -1)
1858 spec.field_width = default_width;
1859 return string(buf, end, "(null)", spec);
1860 }
1861
1862 switch (*fmt) {
1863 case 'F':
1864 case 'f':
1865 case 'S':
1866 case 's':
1867 ptr = dereference_symbol_descriptor(ptr);
1868 /* Fallthrough */
1869 case 'B':
1870 return symbol_string(buf, end, ptr, spec, fmt);
1871 case 'R':
1872 case 'r':
1873 return resource_string(buf, end, ptr, spec, fmt);
1874 case 'h':
1875 return hex_string(buf, end, ptr, spec, fmt);
1876 case 'b':
1877 switch (fmt[1]) {
1878 case 'l':
1879 return bitmap_list_string(buf, end, ptr, spec, fmt);
1880 default:
1881 return bitmap_string(buf, end, ptr, spec, fmt);
1882 }
1883 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1884 case 'm': /* Contiguous: 000102030405 */
1885 /* [mM]F (FDDI) */
1886 /* [mM]R (Reverse order; Bluetooth) */
1887 return mac_address_string(buf, end, ptr, spec, fmt);
1888 case 'I': /* Formatted IP supported
1889 * 4: 1.2.3.4
1890 * 6: 0001:0203:...:0708
1891 * 6c: 1::708 or 1::1.2.3.4
1892 */
1893 case 'i': /* Contiguous:
1894 * 4: 001.002.003.004
1895 * 6: 000102...0f
1896 */
1897 switch (fmt[1]) {
1898 case '6':
1899 return ip6_addr_string(buf, end, ptr, spec, fmt);
1900 case '4':
1901 return ip4_addr_string(buf, end, ptr, spec, fmt);
1902 case 'S': {
1903 const union {
1904 struct sockaddr raw;
1905 struct sockaddr_in v4;
1906 struct sockaddr_in6 v6;
1907 } *sa = ptr;
1908
1909 switch (sa->raw.sa_family) {
1910 case AF_INET:
1911 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1912 case AF_INET6:
1913 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1914 default:
1915 return string(buf, end, "(invalid address)", spec);
1916 }}
1917 }
1918 break;
1919 case 'E':
1920 return escaped_string(buf, end, ptr, spec, fmt);
1921 case 'U':
1922 return uuid_string(buf, end, ptr, spec, fmt);
1923 case 'V':
1924 {
1925 va_list va;
1926
1927 va_copy(va, *((struct va_format *)ptr)->va);
1928 buf += vsnprintf(buf, end > buf ? end - buf : 0,
1929 ((struct va_format *)ptr)->fmt, va);
1930 va_end(va);
1931 return buf;
1932 }
1933 case 'K':
1934 if (!kptr_restrict)
1935 break;
1936 return restricted_pointer(buf, end, ptr, spec);
1937 case 'N':
1938 return netdev_bits(buf, end, ptr, fmt);
1939 case 'a':
1940 return address_val(buf, end, ptr, fmt);
1941 case 'd':
1942 return dentry_name(buf, end, ptr, spec, fmt);
1943 case 'C':
1944 return clock(buf, end, ptr, spec, fmt);
1945 case 'D':
1946 return dentry_name(buf, end,
1947 ((const struct file *)ptr)->f_path.dentry,
1948 spec, fmt);
1949#ifdef CONFIG_BLOCK
1950 case 'g':
1951 return bdev_name(buf, end, ptr, spec, fmt);
1952#endif
1953
1954 case 'G':
1955 return flags_string(buf, end, ptr, fmt);
1956 case 'O':
1957 switch (fmt[1]) {
1958 case 'F':
1959 return device_node_string(buf, end, ptr, spec, fmt + 1);
1960 }
1961 case 'x':
1962 return pointer_string(buf, end, ptr, spec);
1963 }
1964
1965 /* default is to _not_ leak addresses, hash before printing */
1966 return ptr_to_id(buf, end, ptr, spec);
1967}
1968
1969/*
1970 * Helper function to decode printf style format.
1971 * Each call decode a token from the format and return the
1972 * number of characters read (or likely the delta where it wants
1973 * to go on the next call).
1974 * The decoded token is returned through the parameters
1975 *
1976 * 'h', 'l', or 'L' for integer fields
1977 * 'z' support added 23/7/1999 S.H.
1978 * 'z' changed to 'Z' --davidm 1/25/99
1979 * 'Z' changed to 'z' --adobriyan 2017-01-25
1980 * 't' added for ptrdiff_t
1981 *
1982 * @fmt: the format string
1983 * @type of the token returned
1984 * @flags: various flags such as +, -, # tokens..
1985 * @field_width: overwritten width
1986 * @base: base of the number (octal, hex, ...)
1987 * @precision: precision of a number
1988 * @qualifier: qualifier of a number (long, size_t, ...)
1989 */
1990static noinline_for_stack
1991int format_decode(const char *fmt, struct printf_spec *spec)
1992{
1993 const char *start = fmt;
1994 char qualifier;
1995
1996 /* we finished early by reading the field width */
1997 if (spec->type == FORMAT_TYPE_WIDTH) {
1998 if (spec->field_width < 0) {
1999 spec->field_width = -spec->field_width;
2000 spec->flags |= LEFT;
2001 }
2002 spec->type = FORMAT_TYPE_NONE;
2003 goto precision;
2004 }
2005
2006 /* we finished early by reading the precision */
2007 if (spec->type == FORMAT_TYPE_PRECISION) {
2008 if (spec->precision < 0)
2009 spec->precision = 0;
2010
2011 spec->type = FORMAT_TYPE_NONE;
2012 goto qualifier;
2013 }
2014
2015 /* By default */
2016 spec->type = FORMAT_TYPE_NONE;
2017
2018 for (; *fmt ; ++fmt) {
2019 if (*fmt == '%')
2020 break;
2021 }
2022
2023 /* Return the current non-format string */
2024 if (fmt != start || !*fmt)
2025 return fmt - start;
2026
2027 /* Process flags */
2028 spec->flags = 0;
2029
2030 while (1) { /* this also skips first '%' */
2031 bool found = true;
2032
2033 ++fmt;
2034
2035 switch (*fmt) {
2036 case '-': spec->flags |= LEFT; break;
2037 case '+': spec->flags |= PLUS; break;
2038 case ' ': spec->flags |= SPACE; break;
2039 case '#': spec->flags |= SPECIAL; break;
2040 case '0': spec->flags |= ZEROPAD; break;
2041 default: found = false;
2042 }
2043
2044 if (!found)
2045 break;
2046 }
2047
2048 /* get field width */
2049 spec->field_width = -1;
2050
2051 if (isdigit(*fmt))
2052 spec->field_width = skip_atoi(&fmt);
2053 else if (*fmt == '*') {
2054 /* it's the next argument */
2055 spec->type = FORMAT_TYPE_WIDTH;
2056 return ++fmt - start;
2057 }
2058
2059precision:
2060 /* get the precision */
2061 spec->precision = -1;
2062 if (*fmt == '.') {
2063 ++fmt;
2064 if (isdigit(*fmt)) {
2065 spec->precision = skip_atoi(&fmt);
2066 if (spec->precision < 0)
2067 spec->precision = 0;
2068 } else if (*fmt == '*') {
2069 /* it's the next argument */
2070 spec->type = FORMAT_TYPE_PRECISION;
2071 return ++fmt - start;
2072 }
2073 }
2074
2075qualifier:
2076 /* get the conversion qualifier */
2077 qualifier = 0;
2078 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2079 *fmt == 'z' || *fmt == 't') {
2080 qualifier = *fmt++;
2081 if (unlikely(qualifier == *fmt)) {
2082 if (qualifier == 'l') {
2083 qualifier = 'L';
2084 ++fmt;
2085 } else if (qualifier == 'h') {
2086 qualifier = 'H';
2087 ++fmt;
2088 }
2089 }
2090 }
2091
2092 /* default base */
2093 spec->base = 10;
2094 switch (*fmt) {
2095 case 'c':
2096 spec->type = FORMAT_TYPE_CHAR;
2097 return ++fmt - start;
2098
2099 case 's':
2100 spec->type = FORMAT_TYPE_STR;
2101 return ++fmt - start;
2102
2103 case 'p':
2104 spec->type = FORMAT_TYPE_PTR;
2105 return ++fmt - start;
2106
2107 case '%':
2108 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2109 return ++fmt - start;
2110
2111 /* integer number formats - set up the flags and "break" */
2112 case 'o':
2113 spec->base = 8;
2114 break;
2115
2116 case 'x':
2117 spec->flags |= SMALL;
2118
2119 case 'X':
2120 spec->base = 16;
2121 break;
2122
2123 case 'd':
2124 case 'i':
2125 spec->flags |= SIGN;
2126 case 'u':
2127 break;
2128
2129 case 'n':
2130 /*
2131 * Since %n poses a greater security risk than
2132 * utility, treat it as any other invalid or
2133 * unsupported format specifier.
2134 */
2135 /* Fall-through */
2136
2137 default:
2138 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2139 spec->type = FORMAT_TYPE_INVALID;
2140 return fmt - start;
2141 }
2142
2143 if (qualifier == 'L')
2144 spec->type = FORMAT_TYPE_LONG_LONG;
2145 else if (qualifier == 'l') {
2146 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2147 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2148 } else if (qualifier == 'z') {
2149 spec->type = FORMAT_TYPE_SIZE_T;
2150 } else if (qualifier == 't') {
2151 spec->type = FORMAT_TYPE_PTRDIFF;
2152 } else if (qualifier == 'H') {
2153 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2154 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2155 } else if (qualifier == 'h') {
2156 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2157 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2158 } else {
2159 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2160 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2161 }
2162
2163 return ++fmt - start;
2164}
2165
2166static void
2167set_field_width(struct printf_spec *spec, int width)
2168{
2169 spec->field_width = width;
2170 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2171 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2172 }
2173}
2174
2175static void
2176set_precision(struct printf_spec *spec, int prec)
2177{
2178 spec->precision = prec;
2179 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2180 spec->precision = clamp(prec, 0, PRECISION_MAX);
2181 }
2182}
2183
2184/**
2185 * vsnprintf - Format a string and place it in a buffer
2186 * @buf: The buffer to place the result into
2187 * @size: The size of the buffer, including the trailing null space
2188 * @fmt: The format string to use
2189 * @args: Arguments for the format string
2190 *
2191 * This function generally follows C99 vsnprintf, but has some
2192 * extensions and a few limitations:
2193 *
2194 * - ``%n`` is unsupported
2195 * - ``%p*`` is handled by pointer()
2196 *
2197 * See pointer() or Documentation/core-api/printk-formats.rst for more
2198 * extensive description.
2199 *
2200 * **Please update the documentation in both places when making changes**
2201 *
2202 * The return value is the number of characters which would
2203 * be generated for the given input, excluding the trailing
2204 * '\0', as per ISO C99. If you want to have the exact
2205 * number of characters written into @buf as return value
2206 * (not including the trailing '\0'), use vscnprintf(). If the
2207 * return is greater than or equal to @size, the resulting
2208 * string is truncated.
2209 *
2210 * If you're not already dealing with a va_list consider using snprintf().
2211 */
2212int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2213{
2214 unsigned long long num;
2215 char *str, *end;
2216 struct printf_spec spec = {0};
2217
2218 /* Reject out-of-range values early. Large positive sizes are
2219 used for unknown buffer sizes. */
2220 if (WARN_ON_ONCE(size > INT_MAX))
2221 return 0;
2222
2223 str = buf;
2224 end = buf + size;
2225
2226 /* Make sure end is always >= buf */
2227 if (end < buf) {
2228 end = ((void *)-1);
2229 size = end - buf;
2230 }
2231
2232 while (*fmt) {
2233 const char *old_fmt = fmt;
2234 int read = format_decode(fmt, &spec);
2235
2236 fmt += read;
2237
2238 switch (spec.type) {
2239 case FORMAT_TYPE_NONE: {
2240 int copy = read;
2241 if (str < end) {
2242 if (copy > end - str)
2243 copy = end - str;
2244 memcpy(str, old_fmt, copy);
2245 }
2246 str += read;
2247 break;
2248 }
2249
2250 case FORMAT_TYPE_WIDTH:
2251 set_field_width(&spec, va_arg(args, int));
2252 break;
2253
2254 case FORMAT_TYPE_PRECISION:
2255 set_precision(&spec, va_arg(args, int));
2256 break;
2257
2258 case FORMAT_TYPE_CHAR: {
2259 char c;
2260
2261 if (!(spec.flags & LEFT)) {
2262 while (--spec.field_width > 0) {
2263 if (str < end)
2264 *str = ' ';
2265 ++str;
2266
2267 }
2268 }
2269 c = (unsigned char) va_arg(args, int);
2270 if (str < end)
2271 *str = c;
2272 ++str;
2273 while (--spec.field_width > 0) {
2274 if (str < end)
2275 *str = ' ';
2276 ++str;
2277 }
2278 break;
2279 }
2280
2281 case FORMAT_TYPE_STR:
2282 str = string(str, end, va_arg(args, char *), spec);
2283 break;
2284
2285 case FORMAT_TYPE_PTR:
2286 str = pointer(fmt, str, end, va_arg(args, void *),
2287 spec);
2288 while (isalnum(*fmt))
2289 fmt++;
2290 break;
2291
2292 case FORMAT_TYPE_PERCENT_CHAR:
2293 if (str < end)
2294 *str = '%';
2295 ++str;
2296 break;
2297
2298 case FORMAT_TYPE_INVALID:
2299 /*
2300 * Presumably the arguments passed gcc's type
2301 * checking, but there is no safe or sane way
2302 * for us to continue parsing the format and
2303 * fetching from the va_list; the remaining
2304 * specifiers and arguments would be out of
2305 * sync.
2306 */
2307 goto out;
2308
2309 default:
2310 switch (spec.type) {
2311 case FORMAT_TYPE_LONG_LONG:
2312 num = va_arg(args, long long);
2313 break;
2314 case FORMAT_TYPE_ULONG:
2315 num = va_arg(args, unsigned long);
2316 break;
2317 case FORMAT_TYPE_LONG:
2318 num = va_arg(args, long);
2319 break;
2320 case FORMAT_TYPE_SIZE_T:
2321 if (spec.flags & SIGN)
2322 num = va_arg(args, ssize_t);
2323 else
2324 num = va_arg(args, size_t);
2325 break;
2326 case FORMAT_TYPE_PTRDIFF:
2327 num = va_arg(args, ptrdiff_t);
2328 break;
2329 case FORMAT_TYPE_UBYTE:
2330 num = (unsigned char) va_arg(args, int);
2331 break;
2332 case FORMAT_TYPE_BYTE:
2333 num = (signed char) va_arg(args, int);
2334 break;
2335 case FORMAT_TYPE_USHORT:
2336 num = (unsigned short) va_arg(args, int);
2337 break;
2338 case FORMAT_TYPE_SHORT:
2339 num = (short) va_arg(args, int);
2340 break;
2341 case FORMAT_TYPE_INT:
2342 num = (int) va_arg(args, int);
2343 break;
2344 default:
2345 num = va_arg(args, unsigned int);
2346 }
2347
2348 str = number(str, end, num, spec);
2349 }
2350 }
2351
2352out:
2353 if (size > 0) {
2354 if (str < end)
2355 *str = '\0';
2356 else
2357 end[-1] = '\0';
2358 }
2359
2360 /* the trailing null byte doesn't count towards the total */
2361 return str-buf;
2362
2363}
2364EXPORT_SYMBOL(vsnprintf);
2365
2366/**
2367 * vscnprintf - Format a string and place it in a buffer
2368 * @buf: The buffer to place the result into
2369 * @size: The size of the buffer, including the trailing null space
2370 * @fmt: The format string to use
2371 * @args: Arguments for the format string
2372 *
2373 * The return value is the number of characters which have been written into
2374 * the @buf not including the trailing '\0'. If @size is == 0 the function
2375 * returns 0.
2376 *
2377 * If you're not already dealing with a va_list consider using scnprintf().
2378 *
2379 * See the vsnprintf() documentation for format string extensions over C99.
2380 */
2381int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2382{
2383 int i;
2384
2385 i = vsnprintf(buf, size, fmt, args);
2386
2387 if (likely(i < size))
2388 return i;
2389 if (size != 0)
2390 return size - 1;
2391 return 0;
2392}
2393EXPORT_SYMBOL(vscnprintf);
2394
2395/**
2396 * snprintf - Format a string and place it in a buffer
2397 * @buf: The buffer to place the result into
2398 * @size: The size of the buffer, including the trailing null space
2399 * @fmt: The format string to use
2400 * @...: Arguments for the format string
2401 *
2402 * The return value is the number of characters which would be
2403 * generated for the given input, excluding the trailing null,
2404 * as per ISO C99. If the return is greater than or equal to
2405 * @size, the resulting string is truncated.
2406 *
2407 * See the vsnprintf() documentation for format string extensions over C99.
2408 */
2409int snprintf(char *buf, size_t size, const char *fmt, ...)
2410{
2411 va_list args;
2412 int i;
2413
2414 va_start(args, fmt);
2415 i = vsnprintf(buf, size, fmt, args);
2416 va_end(args);
2417
2418 return i;
2419}
2420EXPORT_SYMBOL(snprintf);
2421
2422/**
2423 * scnprintf - Format a string and place it in a buffer
2424 * @buf: The buffer to place the result into
2425 * @size: The size of the buffer, including the trailing null space
2426 * @fmt: The format string to use
2427 * @...: Arguments for the format string
2428 *
2429 * The return value is the number of characters written into @buf not including
2430 * the trailing '\0'. If @size is == 0 the function returns 0.
2431 */
2432
2433int scnprintf(char *buf, size_t size, const char *fmt, ...)
2434{
2435 va_list args;
2436 int i;
2437
2438 va_start(args, fmt);
2439 i = vscnprintf(buf, size, fmt, args);
2440 va_end(args);
2441
2442 return i;
2443}
2444EXPORT_SYMBOL(scnprintf);
2445
2446/**
2447 * vsprintf - Format a string and place it in a buffer
2448 * @buf: The buffer to place the result into
2449 * @fmt: The format string to use
2450 * @args: Arguments for the format string
2451 *
2452 * The function returns the number of characters written
2453 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2454 * buffer overflows.
2455 *
2456 * If you're not already dealing with a va_list consider using sprintf().
2457 *
2458 * See the vsnprintf() documentation for format string extensions over C99.
2459 */
2460int vsprintf(char *buf, const char *fmt, va_list args)
2461{
2462 return vsnprintf(buf, INT_MAX, fmt, args);
2463}
2464EXPORT_SYMBOL(vsprintf);
2465
2466/**
2467 * sprintf - Format a string and place it in a buffer
2468 * @buf: The buffer to place the result into
2469 * @fmt: The format string to use
2470 * @...: Arguments for the format string
2471 *
2472 * The function returns the number of characters written
2473 * into @buf. Use snprintf() or scnprintf() in order to avoid
2474 * buffer overflows.
2475 *
2476 * See the vsnprintf() documentation for format string extensions over C99.
2477 */
2478int sprintf(char *buf, const char *fmt, ...)
2479{
2480 va_list args;
2481 int i;
2482
2483 va_start(args, fmt);
2484 i = vsnprintf(buf, INT_MAX, fmt, args);
2485 va_end(args);
2486
2487 return i;
2488}
2489EXPORT_SYMBOL(sprintf);
2490
2491#ifdef CONFIG_BINARY_PRINTF
2492/*
2493 * bprintf service:
2494 * vbin_printf() - VA arguments to binary data
2495 * bstr_printf() - Binary data to text string
2496 */
2497
2498/**
2499 * vbin_printf - Parse a format string and place args' binary value in a buffer
2500 * @bin_buf: The buffer to place args' binary value
2501 * @size: The size of the buffer(by words(32bits), not characters)
2502 * @fmt: The format string to use
2503 * @args: Arguments for the format string
2504 *
2505 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2506 * is skipped.
2507 *
2508 * The return value is the number of words(32bits) which would be generated for
2509 * the given input.
2510 *
2511 * NOTE:
2512 * If the return value is greater than @size, the resulting bin_buf is NOT
2513 * valid for bstr_printf().
2514 */
2515int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2516{
2517 struct printf_spec spec = {0};
2518 char *str, *end;
2519 int width;
2520
2521 str = (char *)bin_buf;
2522 end = (char *)(bin_buf + size);
2523
2524#define save_arg(type) \
2525({ \
2526 unsigned long long value; \
2527 if (sizeof(type) == 8) { \
2528 unsigned long long val8; \
2529 str = PTR_ALIGN(str, sizeof(u32)); \
2530 val8 = va_arg(args, unsigned long long); \
2531 if (str + sizeof(type) <= end) { \
2532 *(u32 *)str = *(u32 *)&val8; \
2533 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
2534 } \
2535 value = val8; \
2536 } else { \
2537 unsigned int val4; \
2538 str = PTR_ALIGN(str, sizeof(type)); \
2539 val4 = va_arg(args, int); \
2540 if (str + sizeof(type) <= end) \
2541 *(typeof(type) *)str = (type)(long)val4; \
2542 value = (unsigned long long)val4; \
2543 } \
2544 str += sizeof(type); \
2545 value; \
2546})
2547
2548 while (*fmt) {
2549 int read = format_decode(fmt, &spec);
2550
2551 fmt += read;
2552
2553 switch (spec.type) {
2554 case FORMAT_TYPE_NONE:
2555 case FORMAT_TYPE_PERCENT_CHAR:
2556 break;
2557 case FORMAT_TYPE_INVALID:
2558 goto out;
2559
2560 case FORMAT_TYPE_WIDTH:
2561 case FORMAT_TYPE_PRECISION:
2562 width = (int)save_arg(int);
2563 /* Pointers may require the width */
2564 if (*fmt == 'p')
2565 set_field_width(&spec, width);
2566 break;
2567
2568 case FORMAT_TYPE_CHAR:
2569 save_arg(char);
2570 break;
2571
2572 case FORMAT_TYPE_STR: {
2573 const char *save_str = va_arg(args, char *);
2574 size_t len;
2575
2576 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2577 || (unsigned long)save_str < PAGE_SIZE)
2578 save_str = "(null)";
2579 len = strlen(save_str) + 1;
2580 if (str + len < end)
2581 memcpy(str, save_str, len);
2582 str += len;
2583 break;
2584 }
2585
2586 case FORMAT_TYPE_PTR:
2587 /* Dereferenced pointers must be done now */
2588 switch (*fmt) {
2589 /* Dereference of functions is still OK */
2590 case 'S':
2591 case 's':
2592 case 'F':
2593 case 'f':
2594 save_arg(void *);
2595 break;
2596 default:
2597 if (!isalnum(*fmt)) {
2598 save_arg(void *);
2599 break;
2600 }
2601 str = pointer(fmt, str, end, va_arg(args, void *),
2602 spec);
2603 if (str + 1 < end)
2604 *str++ = '\0';
2605 else
2606 end[-1] = '\0'; /* Must be nul terminated */
2607 }
2608 /* skip all alphanumeric pointer suffixes */
2609 while (isalnum(*fmt))
2610 fmt++;
2611 break;
2612
2613 default:
2614 switch (spec.type) {
2615
2616 case FORMAT_TYPE_LONG_LONG:
2617 save_arg(long long);
2618 break;
2619 case FORMAT_TYPE_ULONG:
2620 case FORMAT_TYPE_LONG:
2621 save_arg(unsigned long);
2622 break;
2623 case FORMAT_TYPE_SIZE_T:
2624 save_arg(size_t);
2625 break;
2626 case FORMAT_TYPE_PTRDIFF:
2627 save_arg(ptrdiff_t);
2628 break;
2629 case FORMAT_TYPE_UBYTE:
2630 case FORMAT_TYPE_BYTE:
2631 save_arg(char);
2632 break;
2633 case FORMAT_TYPE_USHORT:
2634 case FORMAT_TYPE_SHORT:
2635 save_arg(short);
2636 break;
2637 default:
2638 save_arg(int);
2639 }
2640 }
2641 }
2642
2643out:
2644 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2645#undef save_arg
2646}
2647EXPORT_SYMBOL_GPL(vbin_printf);
2648
2649/**
2650 * bstr_printf - Format a string from binary arguments and place it in a buffer
2651 * @buf: The buffer to place the result into
2652 * @size: The size of the buffer, including the trailing null space
2653 * @fmt: The format string to use
2654 * @bin_buf: Binary arguments for the format string
2655 *
2656 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2657 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2658 * a binary buffer that generated by vbin_printf.
2659 *
2660 * The format follows C99 vsnprintf, but has some extensions:
2661 * see vsnprintf comment for details.
2662 *
2663 * The return value is the number of characters which would
2664 * be generated for the given input, excluding the trailing
2665 * '\0', as per ISO C99. If you want to have the exact
2666 * number of characters written into @buf as return value
2667 * (not including the trailing '\0'), use vscnprintf(). If the
2668 * return is greater than or equal to @size, the resulting
2669 * string is truncated.
2670 */
2671int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2672{
2673 struct printf_spec spec = {0};
2674 char *str, *end;
2675 const char *args = (const char *)bin_buf;
2676
2677 if (WARN_ON_ONCE(size > INT_MAX))
2678 return 0;
2679
2680 str = buf;
2681 end = buf + size;
2682
2683#define get_arg(type) \
2684({ \
2685 typeof(type) value; \
2686 if (sizeof(type) == 8) { \
2687 args = PTR_ALIGN(args, sizeof(u32)); \
2688 *(u32 *)&value = *(u32 *)args; \
2689 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
2690 } else { \
2691 args = PTR_ALIGN(args, sizeof(type)); \
2692 value = *(typeof(type) *)args; \
2693 } \
2694 args += sizeof(type); \
2695 value; \
2696})
2697
2698 /* Make sure end is always >= buf */
2699 if (end < buf) {
2700 end = ((void *)-1);
2701 size = end - buf;
2702 }
2703
2704 while (*fmt) {
2705 const char *old_fmt = fmt;
2706 int read = format_decode(fmt, &spec);
2707
2708 fmt += read;
2709
2710 switch (spec.type) {
2711 case FORMAT_TYPE_NONE: {
2712 int copy = read;
2713 if (str < end) {
2714 if (copy > end - str)
2715 copy = end - str;
2716 memcpy(str, old_fmt, copy);
2717 }
2718 str += read;
2719 break;
2720 }
2721
2722 case FORMAT_TYPE_WIDTH:
2723 set_field_width(&spec, get_arg(int));
2724 break;
2725
2726 case FORMAT_TYPE_PRECISION:
2727 set_precision(&spec, get_arg(int));
2728 break;
2729
2730 case FORMAT_TYPE_CHAR: {
2731 char c;
2732
2733 if (!(spec.flags & LEFT)) {
2734 while (--spec.field_width > 0) {
2735 if (str < end)
2736 *str = ' ';
2737 ++str;
2738 }
2739 }
2740 c = (unsigned char) get_arg(char);
2741 if (str < end)
2742 *str = c;
2743 ++str;
2744 while (--spec.field_width > 0) {
2745 if (str < end)
2746 *str = ' ';
2747 ++str;
2748 }
2749 break;
2750 }
2751
2752 case FORMAT_TYPE_STR: {
2753 const char *str_arg = args;
2754 args += strlen(str_arg) + 1;
2755 str = string(str, end, (char *)str_arg, spec);
2756 break;
2757 }
2758
2759 case FORMAT_TYPE_PTR: {
2760 bool process = false;
2761 int copy, len;
2762 /* Non function dereferences were already done */
2763 switch (*fmt) {
2764 case 'S':
2765 case 's':
2766 case 'F':
2767 case 'f':
2768 process = true;
2769 break;
2770 default:
2771 if (!isalnum(*fmt)) {
2772 process = true;
2773 break;
2774 }
2775 /* Pointer dereference was already processed */
2776 if (str < end) {
2777 len = copy = strlen(args);
2778 if (copy > end - str)
2779 copy = end - str;
2780 memcpy(str, args, copy);
2781 str += len;
2782 args += len;
2783 }
2784 }
2785 if (process)
2786 str = pointer(fmt, str, end, get_arg(void *), spec);
2787
2788 while (isalnum(*fmt))
2789 fmt++;
2790 break;
2791 }
2792
2793 case FORMAT_TYPE_PERCENT_CHAR:
2794 if (str < end)
2795 *str = '%';
2796 ++str;
2797 break;
2798
2799 case FORMAT_TYPE_INVALID:
2800 goto out;
2801
2802 default: {
2803 unsigned long long num;
2804
2805 switch (spec.type) {
2806
2807 case FORMAT_TYPE_LONG_LONG:
2808 num = get_arg(long long);
2809 break;
2810 case FORMAT_TYPE_ULONG:
2811 case FORMAT_TYPE_LONG:
2812 num = get_arg(unsigned long);
2813 break;
2814 case FORMAT_TYPE_SIZE_T:
2815 num = get_arg(size_t);
2816 break;
2817 case FORMAT_TYPE_PTRDIFF:
2818 num = get_arg(ptrdiff_t);
2819 break;
2820 case FORMAT_TYPE_UBYTE:
2821 num = get_arg(unsigned char);
2822 break;
2823 case FORMAT_TYPE_BYTE:
2824 num = get_arg(signed char);
2825 break;
2826 case FORMAT_TYPE_USHORT:
2827 num = get_arg(unsigned short);
2828 break;
2829 case FORMAT_TYPE_SHORT:
2830 num = get_arg(short);
2831 break;
2832 case FORMAT_TYPE_UINT:
2833 num = get_arg(unsigned int);
2834 break;
2835 default:
2836 num = get_arg(int);
2837 }
2838
2839 str = number(str, end, num, spec);
2840 } /* default: */
2841 } /* switch(spec.type) */
2842 } /* while(*fmt) */
2843
2844out:
2845 if (size > 0) {
2846 if (str < end)
2847 *str = '\0';
2848 else
2849 end[-1] = '\0';
2850 }
2851
2852#undef get_arg
2853
2854 /* the trailing null byte doesn't count towards the total */
2855 return str - buf;
2856}
2857EXPORT_SYMBOL_GPL(bstr_printf);
2858
2859/**
2860 * bprintf - Parse a format string and place args' binary value in a buffer
2861 * @bin_buf: The buffer to place args' binary value
2862 * @size: The size of the buffer(by words(32bits), not characters)
2863 * @fmt: The format string to use
2864 * @...: Arguments for the format string
2865 *
2866 * The function returns the number of words(u32) written
2867 * into @bin_buf.
2868 */
2869int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2870{
2871 va_list args;
2872 int ret;
2873
2874 va_start(args, fmt);
2875 ret = vbin_printf(bin_buf, size, fmt, args);
2876 va_end(args);
2877
2878 return ret;
2879}
2880EXPORT_SYMBOL_GPL(bprintf);
2881
2882#endif /* CONFIG_BINARY_PRINTF */
2883
2884/**
2885 * vsscanf - Unformat a buffer into a list of arguments
2886 * @buf: input buffer
2887 * @fmt: format of buffer
2888 * @args: arguments
2889 */
2890int vsscanf(const char *buf, const char *fmt, va_list args)
2891{
2892 const char *str = buf;
2893 char *next;
2894 char digit;
2895 int num = 0;
2896 u8 qualifier;
2897 unsigned int base;
2898 union {
2899 long long s;
2900 unsigned long long u;
2901 } val;
2902 s16 field_width;
2903 bool is_sign;
2904
2905 while (*fmt) {
2906 /* skip any white space in format */
2907 /* white space in format matchs any amount of
2908 * white space, including none, in the input.
2909 */
2910 if (isspace(*fmt)) {
2911 fmt = skip_spaces(++fmt);
2912 str = skip_spaces(str);
2913 }
2914
2915 /* anything that is not a conversion must match exactly */
2916 if (*fmt != '%' && *fmt) {
2917 if (*fmt++ != *str++)
2918 break;
2919 continue;
2920 }
2921
2922 if (!*fmt)
2923 break;
2924 ++fmt;
2925
2926 /* skip this conversion.
2927 * advance both strings to next white space
2928 */
2929 if (*fmt == '*') {
2930 if (!*str)
2931 break;
2932 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
2933 /* '%*[' not yet supported, invalid format */
2934 if (*fmt == '[')
2935 return num;
2936 fmt++;
2937 }
2938 while (!isspace(*str) && *str)
2939 str++;
2940 continue;
2941 }
2942
2943 /* get field width */
2944 field_width = -1;
2945 if (isdigit(*fmt)) {
2946 field_width = skip_atoi(&fmt);
2947 if (field_width <= 0)
2948 break;
2949 }
2950
2951 /* get conversion qualifier */
2952 qualifier = -1;
2953 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2954 *fmt == 'z') {
2955 qualifier = *fmt++;
2956 if (unlikely(qualifier == *fmt)) {
2957 if (qualifier == 'h') {
2958 qualifier = 'H';
2959 fmt++;
2960 } else if (qualifier == 'l') {
2961 qualifier = 'L';
2962 fmt++;
2963 }
2964 }
2965 }
2966
2967 if (!*fmt)
2968 break;
2969
2970 if (*fmt == 'n') {
2971 /* return number of characters read so far */
2972 *va_arg(args, int *) = str - buf;
2973 ++fmt;
2974 continue;
2975 }
2976
2977 if (!*str)
2978 break;
2979
2980 base = 10;
2981 is_sign = false;
2982
2983 switch (*fmt++) {
2984 case 'c':
2985 {
2986 char *s = (char *)va_arg(args, char*);
2987 if (field_width == -1)
2988 field_width = 1;
2989 do {
2990 *s++ = *str++;
2991 } while (--field_width > 0 && *str);
2992 num++;
2993 }
2994 continue;
2995 case 's':
2996 {
2997 char *s = (char *)va_arg(args, char *);
2998 if (field_width == -1)
2999 field_width = SHRT_MAX;
3000 /* first, skip leading white space in buffer */
3001 str = skip_spaces(str);
3002
3003 /* now copy until next white space */
3004 while (*str && !isspace(*str) && field_width--)
3005 *s++ = *str++;
3006 *s = '\0';
3007 num++;
3008 }
3009 continue;
3010 /*
3011 * Warning: This implementation of the '[' conversion specifier
3012 * deviates from its glibc counterpart in the following ways:
3013 * (1) It does NOT support ranges i.e. '-' is NOT a special
3014 * character
3015 * (2) It cannot match the closing bracket ']' itself
3016 * (3) A field width is required
3017 * (4) '%*[' (discard matching input) is currently not supported
3018 *
3019 * Example usage:
3020 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3021 * buf1, buf2, buf3);
3022 * if (ret < 3)
3023 * // etc..
3024 */
3025 case '[':
3026 {
3027 char *s = (char *)va_arg(args, char *);
3028 DECLARE_BITMAP(set, 256) = {0};
3029 unsigned int len = 0;
3030 bool negate = (*fmt == '^');
3031
3032 /* field width is required */
3033 if (field_width == -1)
3034 return num;
3035
3036 if (negate)
3037 ++fmt;
3038
3039 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3040 set_bit((u8)*fmt, set);
3041
3042 /* no ']' or no character set found */
3043 if (!*fmt || !len)
3044 return num;
3045 ++fmt;
3046
3047 if (negate) {
3048 bitmap_complement(set, set, 256);
3049 /* exclude null '\0' byte */
3050 clear_bit(0, set);
3051 }
3052
3053 /* match must be non-empty */
3054 if (!test_bit((u8)*str, set))
3055 return num;
3056
3057 while (test_bit((u8)*str, set) && field_width--)
3058 *s++ = *str++;
3059 *s = '\0';
3060 ++num;
3061 }
3062 continue;
3063 case 'o':
3064 base = 8;
3065 break;
3066 case 'x':
3067 case 'X':
3068 base = 16;
3069 break;
3070 case 'i':
3071 base = 0;
3072 case 'd':
3073 is_sign = true;
3074 case 'u':
3075 break;
3076 case '%':
3077 /* looking for '%' in str */
3078 if (*str++ != '%')
3079 return num;
3080 continue;
3081 default:
3082 /* invalid format; stop here */
3083 return num;
3084 }
3085
3086 /* have some sort of integer conversion.
3087 * first, skip white space in buffer.
3088 */
3089 str = skip_spaces(str);
3090
3091 digit = *str;
3092 if (is_sign && digit == '-')
3093 digit = *(str + 1);
3094
3095 if (!digit
3096 || (base == 16 && !isxdigit(digit))
3097 || (base == 10 && !isdigit(digit))
3098 || (base == 8 && (!isdigit(digit) || digit > '7'))
3099 || (base == 0 && !isdigit(digit)))
3100 break;
3101
3102 if (is_sign)
3103 val.s = qualifier != 'L' ?
3104 simple_strtol(str, &next, base) :
3105 simple_strtoll(str, &next, base);
3106 else
3107 val.u = qualifier != 'L' ?
3108 simple_strtoul(str, &next, base) :
3109 simple_strtoull(str, &next, base);
3110
3111 if (field_width > 0 && next - str > field_width) {
3112 if (base == 0)
3113 _parse_integer_fixup_radix(str, &base);
3114 while (next - str > field_width) {
3115 if (is_sign)
3116 val.s = div_s64(val.s, base);
3117 else
3118 val.u = div_u64(val.u, base);
3119 --next;
3120 }
3121 }
3122
3123 switch (qualifier) {
3124 case 'H': /* that's 'hh' in format */
3125 if (is_sign)
3126 *va_arg(args, signed char *) = val.s;
3127 else
3128 *va_arg(args, unsigned char *) = val.u;
3129 break;
3130 case 'h':
3131 if (is_sign)
3132 *va_arg(args, short *) = val.s;
3133 else
3134 *va_arg(args, unsigned short *) = val.u;
3135 break;
3136 case 'l':
3137 if (is_sign)
3138 *va_arg(args, long *) = val.s;
3139 else
3140 *va_arg(args, unsigned long *) = val.u;
3141 break;
3142 case 'L':
3143 if (is_sign)
3144 *va_arg(args, long long *) = val.s;
3145 else
3146 *va_arg(args, unsigned long long *) = val.u;
3147 break;
3148 case 'z':
3149 *va_arg(args, size_t *) = val.u;
3150 break;
3151 default:
3152 if (is_sign)
3153 *va_arg(args, int *) = val.s;
3154 else
3155 *va_arg(args, unsigned int *) = val.u;
3156 break;
3157 }
3158 num++;
3159
3160 if (!next)
3161 break;
3162 str = next;
3163 }
3164
3165 return num;
3166}
3167EXPORT_SYMBOL(vsscanf);
3168
3169/**
3170 * sscanf - Unformat a buffer into a list of arguments
3171 * @buf: input buffer
3172 * @fmt: formatting of buffer
3173 * @...: resulting arguments
3174 */
3175int sscanf(const char *buf, const char *fmt, ...)
3176{
3177 va_list args;
3178 int i;
3179
3180 va_start(args, fmt);
3181 i = vsscanf(buf, fmt, args);
3182 va_end(args);
3183
3184 return i;
3185}
3186EXPORT_SYMBOL(sscanf);