Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

Linux/lib/vsprintf.c

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 51  * This function is obsolete.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 76  * This function is obsolete.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

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