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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/module.h>       /* for KSYM_SYMBOL_LEN */
 21 #include <linux/types.h>
 22 #include <linux/string.h>
 23 #include <linux/ctype.h>
 24 #include <linux/kernel.h>
 25 #include <linux/kallsyms.h>
 26 #include <linux/math64.h>
 27 #include <linux/uaccess.h>
 28 #include <linux/ioport.h>
 29 #include <linux/dcache.h>
 30 #include <linux/cred.h>
 31 #include <net/addrconf.h>
 32 
 33 #include <asm/page.h>           /* for PAGE_SIZE */
 34 #include <asm/sections.h>       /* for dereference_function_descriptor() */
 35 
 36 #include <linux/string_helpers.h>
 37 #include "kstrtox.h"
 38 
 39 /**
 40  * simple_strtoull - convert a string to an unsigned long long
 41  * @cp: The start of the string
 42  * @endp: A pointer to the end of the parsed string will be placed here
 43  * @base: The number base to use
 44  *
 45  * This function is obsolete. Please use kstrtoull instead.
 46  */
 47 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 48 {
 49         unsigned long long result;
 50         unsigned int rv;
 51 
 52         cp = _parse_integer_fixup_radix(cp, &base);
 53         rv = _parse_integer(cp, base, &result);
 54         /* FIXME */
 55         cp += (rv & ~KSTRTOX_OVERFLOW);
 56 
 57         if (endp)
 58                 *endp = (char *)cp;
 59 
 60         return result;
 61 }
 62 EXPORT_SYMBOL(simple_strtoull);
 63 
 64 /**
 65  * simple_strtoul - convert a string to an unsigned long
 66  * @cp: The start of the string
 67  * @endp: A pointer to the end of the parsed string will be placed here
 68  * @base: The number base to use
 69  *
 70  * This function is obsolete. Please use kstrtoul instead.
 71  */
 72 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
 73 {
 74         return simple_strtoull(cp, endp, base);
 75 }
 76 EXPORT_SYMBOL(simple_strtoul);
 77 
 78 /**
 79  * simple_strtol - convert a string to a signed long
 80  * @cp: The start of the string
 81  * @endp: A pointer to the end of the parsed string will be placed here
 82  * @base: The number base to use
 83  *
 84  * This function is obsolete. Please use kstrtol instead.
 85  */
 86 long simple_strtol(const char *cp, char **endp, unsigned int base)
 87 {
 88         if (*cp == '-')
 89                 return -simple_strtoul(cp + 1, endp, base);
 90 
 91         return simple_strtoul(cp, endp, base);
 92 }
 93 EXPORT_SYMBOL(simple_strtol);
 94 
 95 /**
 96  * simple_strtoll - convert a string to a signed long long
 97  * @cp: The start of the string
 98  * @endp: A pointer to the end of the parsed string will be placed here
 99  * @base: The number base to use
100  *
101  * This function is obsolete. Please use kstrtoll instead.
102  */
103 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
104 {
105         if (*cp == '-')
106                 return -simple_strtoull(cp + 1, endp, base);
107 
108         return simple_strtoull(cp, endp, base);
109 }
110 EXPORT_SYMBOL(simple_strtoll);
111 
112 static noinline_for_stack
113 int skip_atoi(const char **s)
114 {
115         int i = 0;
116 
117         while (isdigit(**s))
118                 i = i*10 + *((*s)++) - '';
119 
120         return i;
121 }
122 
123 /* Decimal conversion is by far the most typical, and is used
124  * for /proc and /sys data. This directly impacts e.g. top performance
125  * with many processes running. We optimize it for speed
126  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
127  * (with permission from the author, Douglas W. Jones).
128  */
129 
130 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
131 /* Formats correctly any integer in [0, 999999999] */
132 static noinline_for_stack
133 char *put_dec_full9(char *buf, unsigned q)
134 {
135         unsigned r;
136 
137         /*
138          * Possible ways to approx. divide by 10
139          * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
140          * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
141          * (x * 0x6667) >> 18     x <      43699
142          * (x * 0x3334) >> 17     x <      16389
143          * (x * 0x199a) >> 16     x <      16389
144          * (x * 0x0ccd) >> 15     x <      16389
145          * (x * 0x0667) >> 14     x <       2739
146          * (x * 0x0334) >> 13     x <       1029
147          * (x * 0x019a) >> 12     x <       1029
148          * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
149          * (x * 0x0067) >> 10     x <        179
150          * (x * 0x0034) >>  9     x <         69 same
151          * (x * 0x001a) >>  8     x <         69 same
152          * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
153          * (x * 0x0007) >>  6     x <         19
154          * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
155          */
156         r      = (q * (uint64_t)0x1999999a) >> 32;
157         *buf++ = (q - 10 * r) + ''; /* 1 */
158         q      = (r * (uint64_t)0x1999999a) >> 32;
159         *buf++ = (r - 10 * q) + ''; /* 2 */
160         r      = (q * (uint64_t)0x1999999a) >> 32;
161         *buf++ = (q - 10 * r) + ''; /* 3 */
162         q      = (r * (uint64_t)0x1999999a) >> 32;
163         *buf++ = (r - 10 * q) + ''; /* 4 */
164         r      = (q * (uint64_t)0x1999999a) >> 32;
165         *buf++ = (q - 10 * r) + ''; /* 5 */
166         /* Now value is under 10000, can avoid 64-bit multiply */
167         q      = (r * 0x199a) >> 16;
168         *buf++ = (r - 10 * q)  + ''; /* 6 */
169         r      = (q * 0xcd) >> 11;
170         *buf++ = (q - 10 * r)  + ''; /* 7 */
171         q      = (r * 0xcd) >> 11;
172         *buf++ = (r - 10 * q) + ''; /* 8 */
173         *buf++ = q + ''; /* 9 */
174         return buf;
175 }
176 #endif
177 
178 /* Similar to above but do not pad with zeros.
179  * Code can be easily arranged to print 9 digits too, but our callers
180  * always call put_dec_full9() instead when the number has 9 decimal digits.
181  */
182 static noinline_for_stack
183 char *put_dec_trunc8(char *buf, unsigned r)
184 {
185         unsigned q;
186 
187         /* Copy of previous function's body with added early returns */
188         while (r >= 10000) {
189                 q = r + '';
190                 r  = (r * (uint64_t)0x1999999a) >> 32;
191                 *buf++ = q - 10*r;
192         }
193 
194         q      = (r * 0x199a) >> 16;    /* r <= 9999 */
195         *buf++ = (r - 10 * q)  + '';
196         if (q == 0)
197                 return buf;
198         r      = (q * 0xcd) >> 11;      /* q <= 999 */
199         *buf++ = (q - 10 * r)  + '';
200         if (r == 0)
201                 return buf;
202         q      = (r * 0xcd) >> 11;      /* r <= 99 */
203         *buf++ = (r - 10 * q) + '';
204         if (q == 0)
205                 return buf;
206         *buf++ = q + '';                /* q <= 9 */
207         return buf;
208 }
209 
210 /* There are two algorithms to print larger numbers.
211  * One is generic: divide by 1000000000 and repeatedly print
212  * groups of (up to) 9 digits. It's conceptually simple,
213  * but requires a (unsigned long long) / 1000000000 division.
214  *
215  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
216  * manipulates them cleverly and generates groups of 4 decimal digits.
217  * It so happens that it does NOT require long long division.
218  *
219  * If long is > 32 bits, division of 64-bit values is relatively easy,
220  * and we will use the first algorithm.
221  * If long long is > 64 bits (strange architecture with VERY large long long),
222  * second algorithm can't be used, and we again use the first one.
223  *
224  * Else (if long is 32 bits and long long is 64 bits) we use second one.
225  */
226 
227 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
228 
229 /* First algorithm: generic */
230 
231 static
232 char *put_dec(char *buf, unsigned long long n)
233 {
234         if (n >= 100*1000*1000) {
235                 while (n >= 1000*1000*1000)
236                         buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
237                 if (n >= 100*1000*1000)
238                         return put_dec_full9(buf, n);
239         }
240         return put_dec_trunc8(buf, n);
241 }
242 
243 #else
244 
245 /* Second algorithm: valid only for 64-bit long longs */
246 
247 /* See comment in put_dec_full9 for choice of constants */
248 static noinline_for_stack
249 void put_dec_full4(char *buf, unsigned q)
250 {
251         unsigned r;
252         r      = (q * 0xccd) >> 15;
253         buf[0] = (q - 10 * r) + '';
254         q      = (r * 0xcd) >> 11;
255         buf[1] = (r - 10 * q)  + '';
256         r      = (q * 0xcd) >> 11;
257         buf[2] = (q - 10 * r)  + '';
258         buf[3] = r + '';
259 }
260 
261 /*
262  * Call put_dec_full4 on x % 10000, return x / 10000.
263  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
264  * holds for all x < 1,128,869,999.  The largest value this
265  * helper will ever be asked to convert is 1,125,520,955.
266  * (d1 in the put_dec code, assuming n is all-ones).
267  */
268 static
269 unsigned put_dec_helper4(char *buf, unsigned x)
270 {
271         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
272 
273         put_dec_full4(buf, x - q * 10000);
274         return q;
275 }
276 
277 /* Based on code by Douglas W. Jones found at
278  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
279  * (with permission from the author).
280  * Performs no 64-bit division and hence should be fast on 32-bit machines.
281  */
282 static
283 char *put_dec(char *buf, unsigned long long n)
284 {
285         uint32_t d3, d2, d1, q, h;
286 
287         if (n < 100*1000*1000)
288                 return put_dec_trunc8(buf, n);
289 
290         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
291         h   = (n >> 32);
292         d2  = (h      ) & 0xffff;
293         d3  = (h >> 16); /* implicit "& 0xffff" */
294 
295         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
296         q = put_dec_helper4(buf, q);
297 
298         q += 7671 * d3 + 9496 * d2 + 6 * d1;
299         q = put_dec_helper4(buf+4, q);
300 
301         q += 4749 * d3 + 42 * d2;
302         q = put_dec_helper4(buf+8, q);
303 
304         q += 281 * d3;
305         buf += 12;
306         if (q)
307                 buf = put_dec_trunc8(buf, q);
308         else while (buf[-1] == '')
309                 --buf;
310 
311         return buf;
312 }
313 
314 #endif
315 
316 /*
317  * Convert passed number to decimal string.
318  * Returns the length of string.  On buffer overflow, returns 0.
319  *
320  * If speed is not important, use snprintf(). It's easy to read the code.
321  */
322 int num_to_str(char *buf, int size, unsigned long long num)
323 {
324         char tmp[sizeof(num) * 3];
325         int idx, len;
326 
327         /* put_dec() may work incorrectly for num = 0 (generate "", not "") */
328         if (num <= 9) {
329                 tmp[0] = '' + num;
330                 len = 1;
331         } else {
332                 len = put_dec(tmp, num) - tmp;
333         }
334 
335         if (len > size)
336                 return 0;
337         for (idx = 0; idx < len; ++idx)
338                 buf[idx] = tmp[len - idx - 1];
339         return len;
340 }
341 
342 #define ZEROPAD 1               /* pad with zero */
343 #define SIGN    2               /* unsigned/signed long */
344 #define PLUS    4               /* show plus */
345 #define SPACE   8               /* space if plus */
346 #define LEFT    16              /* left justified */
347 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
348 #define SPECIAL 64              /* prefix hex with "0x", octal with "" */
349 
350 enum format_type {
351         FORMAT_TYPE_NONE, /* Just a string part */
352         FORMAT_TYPE_WIDTH,
353         FORMAT_TYPE_PRECISION,
354         FORMAT_TYPE_CHAR,
355         FORMAT_TYPE_STR,
356         FORMAT_TYPE_PTR,
357         FORMAT_TYPE_PERCENT_CHAR,
358         FORMAT_TYPE_INVALID,
359         FORMAT_TYPE_LONG_LONG,
360         FORMAT_TYPE_ULONG,
361         FORMAT_TYPE_LONG,
362         FORMAT_TYPE_UBYTE,
363         FORMAT_TYPE_BYTE,
364         FORMAT_TYPE_USHORT,
365         FORMAT_TYPE_SHORT,
366         FORMAT_TYPE_UINT,
367         FORMAT_TYPE_INT,
368         FORMAT_TYPE_SIZE_T,
369         FORMAT_TYPE_PTRDIFF
370 };
371 
372 struct printf_spec {
373         u8      type;           /* format_type enum */
374         u8      flags;          /* flags to number() */
375         u8      base;           /* number base, 8, 10 or 16 only */
376         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
377         s16     field_width;    /* width of output field */
378         s16     precision;      /* # of digits/chars */
379 };
380 
381 static noinline_for_stack
382 char *number(char *buf, char *end, unsigned long long num,
383              struct printf_spec spec)
384 {
385         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
386         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
387 
388         char tmp[66];
389         char sign;
390         char locase;
391         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
392         int i;
393         bool is_zero = num == 0LL;
394 
395         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
396          * produces same digits or (maybe lowercased) letters */
397         locase = (spec.flags & SMALL);
398         if (spec.flags & LEFT)
399                 spec.flags &= ~ZEROPAD;
400         sign = 0;
401         if (spec.flags & SIGN) {
402                 if ((signed long long)num < 0) {
403                         sign = '-';
404                         num = -(signed long long)num;
405                         spec.field_width--;
406                 } else if (spec.flags & PLUS) {
407                         sign = '+';
408                         spec.field_width--;
409                 } else if (spec.flags & SPACE) {
410                         sign = ' ';
411                         spec.field_width--;
412                 }
413         }
414         if (need_pfx) {
415                 if (spec.base == 16)
416                         spec.field_width -= 2;
417                 else if (!is_zero)
418                         spec.field_width--;
419         }
420 
421         /* generate full string in tmp[], in reverse order */
422         i = 0;
423         if (num < spec.base)
424                 tmp[i++] = digits[num] | locase;
425         /* Generic code, for any base:
426         else do {
427                 tmp[i++] = (digits[do_div(num,base)] | locase);
428         } while (num != 0);
429         */
430         else if (spec.base != 10) { /* 8 or 16 */
431                 int mask = spec.base - 1;
432                 int shift = 3;
433 
434                 if (spec.base == 16)
435                         shift = 4;
436                 do {
437                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
438                         num >>= shift;
439                 } while (num);
440         } else { /* base 10 */
441                 i = put_dec(tmp, num) - tmp;
442         }
443 
444         /* printing 100 using %2d gives "100", not "00" */
445         if (i > spec.precision)
446                 spec.precision = i;
447         /* leading space padding */
448         spec.field_width -= spec.precision;
449         if (!(spec.flags & (ZEROPAD+LEFT))) {
450                 while (--spec.field_width >= 0) {
451                         if (buf < end)
452                                 *buf = ' ';
453                         ++buf;
454                 }
455         }
456         /* sign */
457         if (sign) {
458                 if (buf < end)
459                         *buf = sign;
460                 ++buf;
461         }
462         /* "0x" / "" prefix */
463         if (need_pfx) {
464                 if (spec.base == 16 || !is_zero) {
465                         if (buf < end)
466                                 *buf = '';
467                         ++buf;
468                 }
469                 if (spec.base == 16) {
470                         if (buf < end)
471                                 *buf = ('X' | locase);
472                         ++buf;
473                 }
474         }
475         /* zero or space padding */
476         if (!(spec.flags & LEFT)) {
477                 char c = (spec.flags & ZEROPAD) ? '' : ' ';
478                 while (--spec.field_width >= 0) {
479                         if (buf < end)
480                                 *buf = c;
481                         ++buf;
482                 }
483         }
484         /* hmm even more zero padding? */
485         while (i <= --spec.precision) {
486                 if (buf < end)
487                         *buf = '';
488                 ++buf;
489         }
490         /* actual digits of result */
491         while (--i >= 0) {
492                 if (buf < end)
493                         *buf = tmp[i];
494                 ++buf;
495         }
496         /* trailing space padding */
497         while (--spec.field_width >= 0) {
498                 if (buf < end)
499                         *buf = ' ';
500                 ++buf;
501         }
502 
503         return buf;
504 }
505 
506 static noinline_for_stack
507 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
508 {
509         int len, i;
510 
511         if ((unsigned long)s < PAGE_SIZE)
512                 s = "(null)";
513 
514         len = strnlen(s, spec.precision);
515 
516         if (!(spec.flags & LEFT)) {
517                 while (len < spec.field_width--) {
518                         if (buf < end)
519                                 *buf = ' ';
520                         ++buf;
521                 }
522         }
523         for (i = 0; i < len; ++i) {
524                 if (buf < end)
525                         *buf = *s;
526                 ++buf; ++s;
527         }
528         while (len < spec.field_width--) {
529                 if (buf < end)
530                         *buf = ' ';
531                 ++buf;
532         }
533 
534         return buf;
535 }
536 
537 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
538 {
539         size_t size;
540         if (buf >= end) /* nowhere to put anything */
541                 return;
542         size = end - buf;
543         if (size <= spaces) {
544                 memset(buf, ' ', size);
545                 return;
546         }
547         if (len) {
548                 if (len > size - spaces)
549                         len = size - spaces;
550                 memmove(buf + spaces, buf, len);
551         }
552         memset(buf, ' ', spaces);
553 }
554 
555 static noinline_for_stack
556 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
557                   const char *fmt)
558 {
559         const char *array[4], *s;
560         const struct dentry *p;
561         int depth;
562         int i, n;
563 
564         switch (fmt[1]) {
565                 case '2': case '3': case '4':
566                         depth = fmt[1] - '';
567                         break;
568                 default:
569                         depth = 1;
570         }
571 
572         rcu_read_lock();
573         for (i = 0; i < depth; i++, d = p) {
574                 p = ACCESS_ONCE(d->d_parent);
575                 array[i] = ACCESS_ONCE(d->d_name.name);
576                 if (p == d) {
577                         if (i)
578                                 array[i] = "";
579                         i++;
580                         break;
581                 }
582         }
583         s = array[--i];
584         for (n = 0; n != spec.precision; n++, buf++) {
585                 char c = *s++;
586                 if (!c) {
587                         if (!i)
588                                 break;
589                         c = '/';
590                         s = array[--i];
591                 }
592                 if (buf < end)
593                         *buf = c;
594         }
595         rcu_read_unlock();
596         if (n < spec.field_width) {
597                 /* we want to pad the sucker */
598                 unsigned spaces = spec.field_width - n;
599                 if (!(spec.flags & LEFT)) {
600                         widen(buf - n, end, n, spaces);
601                         return buf + spaces;
602                 }
603                 while (spaces--) {
604                         if (buf < end)
605                                 *buf = ' ';
606                         ++buf;
607                 }
608         }
609         return buf;
610 }
611 
612 static noinline_for_stack
613 char *symbol_string(char *buf, char *end, void *ptr,
614                     struct printf_spec spec, const char *fmt)
615 {
616         unsigned long value;
617 #ifdef CONFIG_KALLSYMS
618         char sym[KSYM_SYMBOL_LEN];
619 #endif
620 
621         if (fmt[1] == 'R')
622                 ptr = __builtin_extract_return_addr(ptr);
623         value = (unsigned long)ptr;
624 
625 #ifdef CONFIG_KALLSYMS
626         if (*fmt == 'B')
627                 sprint_backtrace(sym, value);
628         else if (*fmt != 'f' && *fmt != 's')
629                 sprint_symbol(sym, value);
630         else
631                 sprint_symbol_no_offset(sym, value);
632 
633         return string(buf, end, sym, spec);
634 #else
635         spec.field_width = 2 * sizeof(void *);
636         spec.flags |= SPECIAL | SMALL | ZEROPAD;
637         spec.base = 16;
638 
639         return number(buf, end, value, spec);
640 #endif
641 }
642 
643 static noinline_for_stack
644 char *resource_string(char *buf, char *end, struct resource *res,
645                       struct printf_spec spec, const char *fmt)
646 {
647 #ifndef IO_RSRC_PRINTK_SIZE
648 #define IO_RSRC_PRINTK_SIZE     6
649 #endif
650 
651 #ifndef MEM_RSRC_PRINTK_SIZE
652 #define MEM_RSRC_PRINTK_SIZE    10
653 #endif
654         static const struct printf_spec io_spec = {
655                 .base = 16,
656                 .field_width = IO_RSRC_PRINTK_SIZE,
657                 .precision = -1,
658                 .flags = SPECIAL | SMALL | ZEROPAD,
659         };
660         static const struct printf_spec mem_spec = {
661                 .base = 16,
662                 .field_width = MEM_RSRC_PRINTK_SIZE,
663                 .precision = -1,
664                 .flags = SPECIAL | SMALL | ZEROPAD,
665         };
666         static const struct printf_spec bus_spec = {
667                 .base = 16,
668                 .field_width = 2,
669                 .precision = -1,
670                 .flags = SMALL | ZEROPAD,
671         };
672         static const struct printf_spec dec_spec = {
673                 .base = 10,
674                 .precision = -1,
675                 .flags = 0,
676         };
677         static const struct printf_spec str_spec = {
678                 .field_width = -1,
679                 .precision = 10,
680                 .flags = LEFT,
681         };
682         static const struct printf_spec flag_spec = {
683                 .base = 16,
684                 .precision = -1,
685                 .flags = SPECIAL | SMALL,
686         };
687 
688         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
689          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
690 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
691 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
692 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
693 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
694         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
695                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
696 
697         char *p = sym, *pend = sym + sizeof(sym);
698         int decode = (fmt[0] == 'R') ? 1 : 0;
699         const struct printf_spec *specp;
700 
701         *p++ = '[';
702         if (res->flags & IORESOURCE_IO) {
703                 p = string(p, pend, "io  ", str_spec);
704                 specp = &io_spec;
705         } else if (res->flags & IORESOURCE_MEM) {
706                 p = string(p, pend, "mem ", str_spec);
707                 specp = &mem_spec;
708         } else if (res->flags & IORESOURCE_IRQ) {
709                 p = string(p, pend, "irq ", str_spec);
710                 specp = &dec_spec;
711         } else if (res->flags & IORESOURCE_DMA) {
712                 p = string(p, pend, "dma ", str_spec);
713                 specp = &dec_spec;
714         } else if (res->flags & IORESOURCE_BUS) {
715                 p = string(p, pend, "bus ", str_spec);
716                 specp = &bus_spec;
717         } else {
718                 p = string(p, pend, "??? ", str_spec);
719                 specp = &mem_spec;
720                 decode = 0;
721         }
722         if (decode && res->flags & IORESOURCE_UNSET) {
723                 p = string(p, pend, "size ", str_spec);
724                 p = number(p, pend, resource_size(res), *specp);
725         } else {
726                 p = number(p, pend, res->start, *specp);
727                 if (res->start != res->end) {
728                         *p++ = '-';
729                         p = number(p, pend, res->end, *specp);
730                 }
731         }
732         if (decode) {
733                 if (res->flags & IORESOURCE_MEM_64)
734                         p = string(p, pend, " 64bit", str_spec);
735                 if (res->flags & IORESOURCE_PREFETCH)
736                         p = string(p, pend, " pref", str_spec);
737                 if (res->flags & IORESOURCE_WINDOW)
738                         p = string(p, pend, " window", str_spec);
739                 if (res->flags & IORESOURCE_DISABLED)
740                         p = string(p, pend, " disabled", str_spec);
741         } else {
742                 p = string(p, pend, " flags ", str_spec);
743                 p = number(p, pend, res->flags, flag_spec);
744         }
745         *p++ = ']';
746         *p = '\0';
747 
748         return string(buf, end, sym, spec);
749 }
750 
751 static noinline_for_stack
752 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
753                  const char *fmt)
754 {
755         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
756                                    negative value, fallback to the default */
757         char separator;
758 
759         if (spec.field_width == 0)
760                 /* nothing to print */
761                 return buf;
762 
763         if (ZERO_OR_NULL_PTR(addr))
764                 /* NULL pointer */
765                 return string(buf, end, NULL, spec);
766 
767         switch (fmt[1]) {
768         case 'C':
769                 separator = ':';
770                 break;
771         case 'D':
772                 separator = '-';
773                 break;
774         case 'N':
775                 separator = 0;
776                 break;
777         default:
778                 separator = ' ';
779                 break;
780         }
781 
782         if (spec.field_width > 0)
783                 len = min_t(int, spec.field_width, 64);
784 
785         for (i = 0; i < len && buf < end - 1; i++) {
786                 buf = hex_byte_pack(buf, addr[i]);
787 
788                 if (buf < end && separator && i != len - 1)
789                         *buf++ = separator;
790         }
791 
792         return buf;
793 }
794 
795 static noinline_for_stack
796 char *mac_address_string(char *buf, char *end, u8 *addr,
797                          struct printf_spec spec, const char *fmt)
798 {
799         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
800         char *p = mac_addr;
801         int i;
802         char separator;
803         bool reversed = false;
804 
805         switch (fmt[1]) {
806         case 'F':
807                 separator = '-';
808                 break;
809 
810         case 'R':
811                 reversed = true;
812                 /* fall through */
813 
814         default:
815                 separator = ':';
816                 break;
817         }
818 
819         for (i = 0; i < 6; i++) {
820                 if (reversed)
821                         p = hex_byte_pack(p, addr[5 - i]);
822                 else
823                         p = hex_byte_pack(p, addr[i]);
824 
825                 if (fmt[0] == 'M' && i != 5)
826                         *p++ = separator;
827         }
828         *p = '\0';
829 
830         return string(buf, end, mac_addr, spec);
831 }
832 
833 static noinline_for_stack
834 char *ip4_string(char *p, const u8 *addr, const char *fmt)
835 {
836         int i;
837         bool leading_zeros = (fmt[0] == 'i');
838         int index;
839         int step;
840 
841         switch (fmt[2]) {
842         case 'h':
843 #ifdef __BIG_ENDIAN
844                 index = 0;
845                 step = 1;
846 #else
847                 index = 3;
848                 step = -1;
849 #endif
850                 break;
851         case 'l':
852                 index = 3;
853                 step = -1;
854                 break;
855         case 'n':
856         case 'b':
857         default:
858                 index = 0;
859                 step = 1;
860                 break;
861         }
862         for (i = 0; i < 4; i++) {
863                 char temp[3];   /* hold each IP quad in reverse order */
864                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
865                 if (leading_zeros) {
866                         if (digits < 3)
867                                 *p++ = '';
868                         if (digits < 2)
869                                 *p++ = '';
870                 }
871                 /* reverse the digits in the quad */
872                 while (digits--)
873                         *p++ = temp[digits];
874                 if (i < 3)
875                         *p++ = '.';
876                 index += step;
877         }
878         *p = '\0';
879 
880         return p;
881 }
882 
883 static noinline_for_stack
884 char *ip6_compressed_string(char *p, const char *addr)
885 {
886         int i, j, range;
887         unsigned char zerolength[8];
888         int longest = 1;
889         int colonpos = -1;
890         u16 word;
891         u8 hi, lo;
892         bool needcolon = false;
893         bool useIPv4;
894         struct in6_addr in6;
895 
896         memcpy(&in6, addr, sizeof(struct in6_addr));
897 
898         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
899 
900         memset(zerolength, 0, sizeof(zerolength));
901 
902         if (useIPv4)
903                 range = 6;
904         else
905                 range = 8;
906 
907         /* find position of longest 0 run */
908         for (i = 0; i < range; i++) {
909                 for (j = i; j < range; j++) {
910                         if (in6.s6_addr16[j] != 0)
911                                 break;
912                         zerolength[i]++;
913                 }
914         }
915         for (i = 0; i < range; i++) {
916                 if (zerolength[i] > longest) {
917                         longest = zerolength[i];
918                         colonpos = i;
919                 }
920         }
921         if (longest == 1)               /* don't compress a single 0 */
922                 colonpos = -1;
923 
924         /* emit address */
925         for (i = 0; i < range; i++) {
926                 if (i == colonpos) {
927                         if (needcolon || i == 0)
928                                 *p++ = ':';
929                         *p++ = ':';
930                         needcolon = false;
931                         i += longest - 1;
932                         continue;
933                 }
934                 if (needcolon) {
935                         *p++ = ':';
936                         needcolon = false;
937                 }
938                 /* hex u16 without leading 0s */
939                 word = ntohs(in6.s6_addr16[i]);
940                 hi = word >> 8;
941                 lo = word & 0xff;
942                 if (hi) {
943                         if (hi > 0x0f)
944                                 p = hex_byte_pack(p, hi);
945                         else
946                                 *p++ = hex_asc_lo(hi);
947                         p = hex_byte_pack(p, lo);
948                 }
949                 else if (lo > 0x0f)
950                         p = hex_byte_pack(p, lo);
951                 else
952                         *p++ = hex_asc_lo(lo);
953                 needcolon = true;
954         }
955 
956         if (useIPv4) {
957                 if (needcolon)
958                         *p++ = ':';
959                 p = ip4_string(p, &in6.s6_addr[12], "I4");
960         }
961         *p = '\0';
962 
963         return p;
964 }
965 
966 static noinline_for_stack
967 char *ip6_string(char *p, const char *addr, const char *fmt)
968 {
969         int i;
970 
971         for (i = 0; i < 8; i++) {
972                 p = hex_byte_pack(p, *addr++);
973                 p = hex_byte_pack(p, *addr++);
974                 if (fmt[0] == 'I' && i != 7)
975                         *p++ = ':';
976         }
977         *p = '\0';
978 
979         return p;
980 }
981 
982 static noinline_for_stack
983 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
984                       struct printf_spec spec, const char *fmt)
985 {
986         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
987 
988         if (fmt[0] == 'I' && fmt[2] == 'c')
989                 ip6_compressed_string(ip6_addr, addr);
990         else
991                 ip6_string(ip6_addr, addr, fmt);
992 
993         return string(buf, end, ip6_addr, spec);
994 }
995 
996 static noinline_for_stack
997 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
998                       struct printf_spec spec, const char *fmt)
999 {
1000         char ip4_addr[sizeof("255.255.255.255")];
1001 
1002         ip4_string(ip4_addr, addr, fmt);
1003 
1004         return string(buf, end, ip4_addr, spec);
1005 }
1006 
1007 static noinline_for_stack
1008 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1009                          struct printf_spec spec, const char *fmt)
1010 {
1011         bool have_p = false, have_s = false, have_f = false, have_c = false;
1012         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1013                       sizeof(":12345") + sizeof("/123456789") +
1014                       sizeof("%1234567890")];
1015         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1016         const u8 *addr = (const u8 *) &sa->sin6_addr;
1017         char fmt6[2] = { fmt[0], '6' };
1018         u8 off = 0;
1019 
1020         fmt++;
1021         while (isalpha(*++fmt)) {
1022                 switch (*fmt) {
1023                 case 'p':
1024                         have_p = true;
1025                         break;
1026                 case 'f':
1027                         have_f = true;
1028                         break;
1029                 case 's':
1030                         have_s = true;
1031                         break;
1032                 case 'c':
1033                         have_c = true;
1034                         break;
1035                 }
1036         }
1037 
1038         if (have_p || have_s || have_f) {
1039                 *p = '[';
1040                 off = 1;
1041         }
1042 
1043         if (fmt6[0] == 'I' && have_c)
1044                 p = ip6_compressed_string(ip6_addr + off, addr);
1045         else
1046                 p = ip6_string(ip6_addr + off, addr, fmt6);
1047 
1048         if (have_p || have_s || have_f)
1049                 *p++ = ']';
1050 
1051         if (have_p) {
1052                 *p++ = ':';
1053                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1054         }
1055         if (have_f) {
1056                 *p++ = '/';
1057                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1058                                           IPV6_FLOWINFO_MASK), spec);
1059         }
1060         if (have_s) {
1061                 *p++ = '%';
1062                 p = number(p, pend, sa->sin6_scope_id, spec);
1063         }
1064         *p = '\0';
1065 
1066         return string(buf, end, ip6_addr, spec);
1067 }
1068 
1069 static noinline_for_stack
1070 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1071                          struct printf_spec spec, const char *fmt)
1072 {
1073         bool have_p = false;
1074         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1075         char *pend = ip4_addr + sizeof(ip4_addr);
1076         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1077         char fmt4[3] = { fmt[0], '4', 0 };
1078 
1079         fmt++;
1080         while (isalpha(*++fmt)) {
1081                 switch (*fmt) {
1082                 case 'p':
1083                         have_p = true;
1084                         break;
1085                 case 'h':
1086                 case 'l':
1087                 case 'n':
1088                 case 'b':
1089                         fmt4[2] = *fmt;
1090                         break;
1091                 }
1092         }
1093 
1094         p = ip4_string(ip4_addr, addr, fmt4);
1095         if (have_p) {
1096                 *p++ = ':';
1097                 p = number(p, pend, ntohs(sa->sin_port), spec);
1098         }
1099         *p = '\0';
1100 
1101         return string(buf, end, ip4_addr, spec);
1102 }
1103 
1104 static noinline_for_stack
1105 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1106                      const char *fmt)
1107 {
1108         bool found = true;
1109         int count = 1;
1110         unsigned int flags = 0;
1111         int len;
1112 
1113         if (spec.field_width == 0)
1114                 return buf;                             /* nothing to print */
1115 
1116         if (ZERO_OR_NULL_PTR(addr))
1117                 return string(buf, end, NULL, spec);    /* NULL pointer */
1118 
1119 
1120         do {
1121                 switch (fmt[count++]) {
1122                 case 'a':
1123                         flags |= ESCAPE_ANY;
1124                         break;
1125                 case 'c':
1126                         flags |= ESCAPE_SPECIAL;
1127                         break;
1128                 case 'h':
1129                         flags |= ESCAPE_HEX;
1130                         break;
1131                 case 'n':
1132                         flags |= ESCAPE_NULL;
1133                         break;
1134                 case 'o':
1135                         flags |= ESCAPE_OCTAL;
1136                         break;
1137                 case 'p':
1138                         flags |= ESCAPE_NP;
1139                         break;
1140                 case 's':
1141                         flags |= ESCAPE_SPACE;
1142                         break;
1143                 default:
1144                         found = false;
1145                         break;
1146                 }
1147         } while (found);
1148 
1149         if (!flags)
1150                 flags = ESCAPE_ANY_NP;
1151 
1152         len = spec.field_width < 0 ? 1 : spec.field_width;
1153 
1154         /* Ignore the error. We print as many characters as we can */
1155         string_escape_mem(addr, len, &buf, end - buf, flags, NULL);
1156 
1157         return buf;
1158 }
1159 
1160 static noinline_for_stack
1161 char *uuid_string(char *buf, char *end, const u8 *addr,
1162                   struct printf_spec spec, const char *fmt)
1163 {
1164         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1165         char *p = uuid;
1166         int i;
1167         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1168         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1169         const u8 *index = be;
1170         bool uc = false;
1171 
1172         switch (*(++fmt)) {
1173         case 'L':
1174                 uc = true;              /* fall-through */
1175         case 'l':
1176                 index = le;
1177                 break;
1178         case 'B':
1179                 uc = true;
1180                 break;
1181         }
1182 
1183         for (i = 0; i < 16; i++) {
1184                 p = hex_byte_pack(p, addr[index[i]]);
1185                 switch (i) {
1186                 case 3:
1187                 case 5:
1188                 case 7:
1189                 case 9:
1190                         *p++ = '-';
1191                         break;
1192                 }
1193         }
1194 
1195         *p = 0;
1196 
1197         if (uc) {
1198                 p = uuid;
1199                 do {
1200                         *p = toupper(*p);
1201                 } while (*(++p));
1202         }
1203 
1204         return string(buf, end, uuid, spec);
1205 }
1206 
1207 static
1208 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1209                       struct printf_spec spec)
1210 {
1211         spec.flags |= SPECIAL | SMALL | ZEROPAD;
1212         if (spec.field_width == -1)
1213                 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1214         spec.base = 16;
1215 
1216         return number(buf, end, *(const netdev_features_t *)addr, spec);
1217 }
1218 
1219 static noinline_for_stack
1220 char *address_val(char *buf, char *end, const void *addr,
1221                   struct printf_spec spec, const char *fmt)
1222 {
1223         unsigned long long num;
1224 
1225         spec.flags |= SPECIAL | SMALL | ZEROPAD;
1226         spec.base = 16;
1227 
1228         switch (fmt[1]) {
1229         case 'd':
1230                 num = *(const dma_addr_t *)addr;
1231                 spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1232                 break;
1233         case 'p':
1234         default:
1235                 num = *(const phys_addr_t *)addr;
1236                 spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1237                 break;
1238         }
1239 
1240         return number(buf, end, num, spec);
1241 }
1242 
1243 int kptr_restrict __read_mostly;
1244 
1245 /*
1246  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1247  * by an extra set of alphanumeric characters that are extended format
1248  * specifiers.
1249  *
1250  * Right now we handle:
1251  *
1252  * - 'F' For symbolic function descriptor pointers with offset
1253  * - 'f' For simple symbolic function names without offset
1254  * - 'S' For symbolic direct pointers with offset
1255  * - 's' For symbolic direct pointers without offset
1256  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1257  * - 'B' For backtraced symbolic direct pointers with offset
1258  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1259  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1260  * - 'M' For a 6-byte MAC address, it prints the address in the
1261  *       usual colon-separated hex notation
1262  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1263  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1264  *       with a dash-separated hex notation
1265  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1266  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1267  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1268  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1269  *       [S][pfs]
1270  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1271  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1272  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1273  *       IPv6 omits the colons (01020304...0f)
1274  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1275  *       [S][pfs]
1276  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1277  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1278  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1279  * - 'I[6S]c' for IPv6 addresses printed as specified by
1280  *       http://tools.ietf.org/html/rfc5952
1281  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1282  *                of the following flags (see string_escape_mem() for the
1283  *                details):
1284  *                  a - ESCAPE_ANY
1285  *                  c - ESCAPE_SPECIAL
1286  *                  h - ESCAPE_HEX
1287  *                  n - ESCAPE_NULL
1288  *                  o - ESCAPE_OCTAL
1289  *                  p - ESCAPE_NP
1290  *                  s - ESCAPE_SPACE
1291  *                By default ESCAPE_ANY_NP is used.
1292  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1293  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1294  *       Options for %pU are:
1295  *         b big endian lower case hex (default)
1296  *         B big endian UPPER case hex
1297  *         l little endian lower case hex
1298  *         L little endian UPPER case hex
1299  *           big endian output byte order is:
1300  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1301  *           little endian output byte order is:
1302  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1303  * - 'V' For a struct va_format which contains a format string * and va_list *,
1304  *       call vsnprintf(->format, *->va_list).
1305  *       Implements a "recursive vsnprintf".
1306  *       Do not use this feature without some mechanism to verify the
1307  *       correctness of the format string and va_list arguments.
1308  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1309  * - 'NF' For a netdev_features_t
1310  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1311  *            a certain separator (' ' by default):
1312  *              C colon
1313  *              D dash
1314  *              N no separator
1315  *            The maximum supported length is 64 bytes of the input. Consider
1316  *            to use print_hex_dump() for the larger input.
1317  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1318  *           (default assumed to be phys_addr_t, passed by reference)
1319  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1320  * - 'D[234]' Same as 'd' but for a struct file
1321  *
1322  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1323  * function pointers are really function descriptors, which contain a
1324  * pointer to the real address.
1325  */
1326 static noinline_for_stack
1327 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1328               struct printf_spec spec)
1329 {
1330         int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1331 
1332         if (!ptr && *fmt != 'K') {
1333                 /*
1334                  * Print (null) with the same width as a pointer so it makes
1335                  * tabular output look nice.
1336                  */
1337                 if (spec.field_width == -1)
1338                         spec.field_width = default_width;
1339                 return string(buf, end, "(null)", spec);
1340         }
1341 
1342         switch (*fmt) {
1343         case 'F':
1344         case 'f':
1345                 ptr = dereference_function_descriptor(ptr);
1346                 /* Fallthrough */
1347         case 'S':
1348         case 's':
1349         case 'B':
1350                 return symbol_string(buf, end, ptr, spec, fmt);
1351         case 'R':
1352         case 'r':
1353                 return resource_string(buf, end, ptr, spec, fmt);
1354         case 'h':
1355                 return hex_string(buf, end, ptr, spec, fmt);
1356         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1357         case 'm':                       /* Contiguous: 000102030405 */
1358                                         /* [mM]F (FDDI) */
1359                                         /* [mM]R (Reverse order; Bluetooth) */
1360                 return mac_address_string(buf, end, ptr, spec, fmt);
1361         case 'I':                       /* Formatted IP supported
1362                                          * 4:   1.2.3.4
1363                                          * 6:   0001:0203:...:0708
1364                                          * 6c:  1::708 or 1::1.2.3.4
1365                                          */
1366         case 'i':                       /* Contiguous:
1367                                          * 4:   001.002.003.004
1368                                          * 6:   000102...0f
1369                                          */
1370                 switch (fmt[1]) {
1371                 case '6':
1372                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1373                 case '4':
1374                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1375                 case 'S': {
1376                         const union {
1377                                 struct sockaddr         raw;
1378                                 struct sockaddr_in      v4;
1379                                 struct sockaddr_in6     v6;
1380                         } *sa = ptr;
1381 
1382                         switch (sa->raw.sa_family) {
1383                         case AF_INET:
1384                                 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1385                         case AF_INET6:
1386                                 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1387                         default:
1388                                 return string(buf, end, "(invalid address)", spec);
1389                         }}
1390                 }
1391                 break;
1392         case 'E':
1393                 return escaped_string(buf, end, ptr, spec, fmt);
1394         case 'U':
1395                 return uuid_string(buf, end, ptr, spec, fmt);
1396         case 'V':
1397                 {
1398                         va_list va;
1399 
1400                         va_copy(va, *((struct va_format *)ptr)->va);
1401                         buf += vsnprintf(buf, end > buf ? end - buf : 0,
1402                                          ((struct va_format *)ptr)->fmt, va);
1403                         va_end(va);
1404                         return buf;
1405                 }
1406         case 'K':
1407                 /*
1408                  * %pK cannot be used in IRQ context because its test
1409                  * for CAP_SYSLOG would be meaningless.
1410                  */
1411                 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1412                                       in_nmi())) {
1413                         if (spec.field_width == -1)
1414                                 spec.field_width = default_width;
1415                         return string(buf, end, "pK-error", spec);
1416                 }
1417 
1418                 switch (kptr_restrict) {
1419                 case 0:
1420                         /* Always print %pK values */
1421                         break;
1422                 case 1: {
1423                         /*
1424                          * Only print the real pointer value if the current
1425                          * process has CAP_SYSLOG and is running with the
1426                          * same credentials it started with. This is because
1427                          * access to files is checked at open() time, but %pK
1428                          * checks permission at read() time. We don't want to
1429                          * leak pointer values if a binary opens a file using
1430                          * %pK and then elevates privileges before reading it.
1431                          */
1432                         const struct cred *cred = current_cred();
1433 
1434                         if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1435                             !uid_eq(cred->euid, cred->uid) ||
1436                             !gid_eq(cred->egid, cred->gid))
1437                                 ptr = NULL;
1438                         break;
1439                 }
1440                 case 2:
1441                 default:
1442                         /* Always print 0's for %pK */
1443                         ptr = NULL;
1444                         break;
1445                 }
1446                 break;
1447 
1448         case 'N':
1449                 switch (fmt[1]) {
1450                 case 'F':
1451                         return netdev_feature_string(buf, end, ptr, spec);
1452                 }
1453                 break;
1454         case 'a':
1455                 return address_val(buf, end, ptr, spec, fmt);
1456         case 'd':
1457                 return dentry_name(buf, end, ptr, spec, fmt);
1458         case 'D':
1459                 return dentry_name(buf, end,
1460                                    ((const struct file *)ptr)->f_path.dentry,
1461                                    spec, fmt);
1462         }
1463         spec.flags |= SMALL;
1464         if (spec.field_width == -1) {
1465                 spec.field_width = default_width;
1466                 spec.flags |= ZEROPAD;
1467         }
1468         spec.base = 16;
1469 
1470         return number(buf, end, (unsigned long) ptr, spec);
1471 }
1472 
1473 /*
1474  * Helper function to decode printf style format.
1475  * Each call decode a token from the format and return the
1476  * number of characters read (or likely the delta where it wants
1477  * to go on the next call).
1478  * The decoded token is returned through the parameters
1479  *
1480  * 'h', 'l', or 'L' for integer fields
1481  * 'z' support added 23/7/1999 S.H.
1482  * 'z' changed to 'Z' --davidm 1/25/99
1483  * 't' added for ptrdiff_t
1484  *
1485  * @fmt: the format string
1486  * @type of the token returned
1487  * @flags: various flags such as +, -, # tokens..
1488  * @field_width: overwritten width
1489  * @base: base of the number (octal, hex, ...)
1490  * @precision: precision of a number
1491  * @qualifier: qualifier of a number (long, size_t, ...)
1492  */
1493 static noinline_for_stack
1494 int format_decode(const char *fmt, struct printf_spec *spec)
1495 {
1496         const char *start = fmt;
1497 
1498         /* we finished early by reading the field width */
1499         if (spec->type == FORMAT_TYPE_WIDTH) {
1500                 if (spec->field_width < 0) {
1501                         spec->field_width = -spec->field_width;
1502                         spec->flags |= LEFT;
1503                 }
1504                 spec->type = FORMAT_TYPE_NONE;
1505                 goto precision;
1506         }
1507 
1508         /* we finished early by reading the precision */
1509         if (spec->type == FORMAT_TYPE_PRECISION) {
1510                 if (spec->precision < 0)
1511                         spec->precision = 0;
1512 
1513                 spec->type = FORMAT_TYPE_NONE;
1514                 goto qualifier;
1515         }
1516 
1517         /* By default */
1518         spec->type = FORMAT_TYPE_NONE;
1519 
1520         for (; *fmt ; ++fmt) {
1521                 if (*fmt == '%')
1522                         break;
1523         }
1524 
1525         /* Return the current non-format string */
1526         if (fmt != start || !*fmt)
1527                 return fmt - start;
1528 
1529         /* Process flags */
1530         spec->flags = 0;
1531 
1532         while (1) { /* this also skips first '%' */
1533                 bool found = true;
1534 
1535                 ++fmt;
1536 
1537                 switch (*fmt) {
1538                 case '-': spec->flags |= LEFT;    break;
1539                 case '+': spec->flags |= PLUS;    break;
1540                 case ' ': spec->flags |= SPACE;   break;
1541                 case '#': spec->flags |= SPECIAL; break;
1542                 case '': spec->flags |= ZEROPAD; break;
1543                 default:  found = false;
1544                 }
1545 
1546                 if (!found)
1547                         break;
1548         }
1549 
1550         /* get field width */
1551         spec->field_width = -1;
1552 
1553         if (isdigit(*fmt))
1554                 spec->field_width = skip_atoi(&fmt);
1555         else if (*fmt == '*') {
1556                 /* it's the next argument */
1557                 spec->type = FORMAT_TYPE_WIDTH;
1558                 return ++fmt - start;
1559         }
1560 
1561 precision:
1562         /* get the precision */
1563         spec->precision = -1;
1564         if (*fmt == '.') {
1565                 ++fmt;
1566                 if (isdigit(*fmt)) {
1567                         spec->precision = skip_atoi(&fmt);
1568                         if (spec->precision < 0)
1569                                 spec->precision = 0;
1570                 } else if (*fmt == '*') {
1571                         /* it's the next argument */
1572                         spec->type = FORMAT_TYPE_PRECISION;
1573                         return ++fmt - start;
1574                 }
1575         }
1576 
1577 qualifier:
1578         /* get the conversion qualifier */
1579         spec->qualifier = -1;
1580         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1581             _tolower(*fmt) == 'z' || *fmt == 't') {
1582                 spec->qualifier = *fmt++;
1583                 if (unlikely(spec->qualifier == *fmt)) {
1584                         if (spec->qualifier == 'l') {
1585                                 spec->qualifier = 'L';
1586                                 ++fmt;
1587                         } else if (spec->qualifier == 'h') {
1588                                 spec->qualifier = 'H';
1589                                 ++fmt;
1590                         }
1591                 }
1592         }
1593 
1594         /* default base */
1595         spec->base = 10;
1596         switch (*fmt) {
1597         case 'c':
1598                 spec->type = FORMAT_TYPE_CHAR;
1599                 return ++fmt - start;
1600 
1601         case 's':
1602                 spec->type = FORMAT_TYPE_STR;
1603                 return ++fmt - start;
1604 
1605         case 'p':
1606                 spec->type = FORMAT_TYPE_PTR;
1607                 return fmt - start;
1608                 /* skip alnum */
1609 
1610         case '%':
1611                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1612                 return ++fmt - start;
1613 
1614         /* integer number formats - set up the flags and "break" */
1615         case 'o':
1616                 spec->base = 8;
1617                 break;
1618 
1619         case 'x':
1620                 spec->flags |= SMALL;
1621 
1622         case 'X':
1623                 spec->base = 16;
1624                 break;
1625 
1626         case 'd':
1627         case 'i':
1628                 spec->flags |= SIGN;
1629         case 'u':
1630                 break;
1631 
1632         case 'n':
1633                 /*
1634                  * Since %n poses a greater security risk than utility, treat
1635                  * it as an invalid format specifier. Warn about its use so
1636                  * that new instances don't get added.
1637                  */
1638                 WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1639                 /* Fall-through */
1640 
1641         default:
1642                 spec->type = FORMAT_TYPE_INVALID;
1643                 return fmt - start;
1644         }
1645 
1646         if (spec->qualifier == 'L')
1647                 spec->type = FORMAT_TYPE_LONG_LONG;
1648         else if (spec->qualifier == 'l') {
1649                 if (spec->flags & SIGN)
1650                         spec->type = FORMAT_TYPE_LONG;
1651                 else
1652                         spec->type = FORMAT_TYPE_ULONG;
1653         } else if (_tolower(spec->qualifier) == 'z') {
1654                 spec->type = FORMAT_TYPE_SIZE_T;
1655         } else if (spec->qualifier == 't') {
1656                 spec->type = FORMAT_TYPE_PTRDIFF;
1657         } else if (spec->qualifier == 'H') {
1658                 if (spec->flags & SIGN)
1659                         spec->type = FORMAT_TYPE_BYTE;
1660                 else
1661                         spec->type = FORMAT_TYPE_UBYTE;
1662         } else if (spec->qualifier == 'h') {
1663                 if (spec->flags & SIGN)
1664                         spec->type = FORMAT_TYPE_SHORT;
1665                 else
1666                         spec->type = FORMAT_TYPE_USHORT;
1667         } else {
1668                 if (spec->flags & SIGN)
1669                         spec->type = FORMAT_TYPE_INT;
1670                 else
1671                         spec->type = FORMAT_TYPE_UINT;
1672         }
1673 
1674         return ++fmt - start;
1675 }
1676 
1677 /**
1678  * vsnprintf - Format a string and place it in a buffer
1679  * @buf: The buffer to place the result into
1680  * @size: The size of the buffer, including the trailing null space
1681  * @fmt: The format string to use
1682  * @args: Arguments for the format string
1683  *
1684  * This function follows C99 vsnprintf, but has some extensions:
1685  * %pS output the name of a text symbol with offset
1686  * %ps output the name of a text symbol without offset
1687  * %pF output the name of a function pointer with its offset
1688  * %pf output the name of a function pointer without its offset
1689  * %pB output the name of a backtrace symbol with its offset
1690  * %pR output the address range in a struct resource with decoded flags
1691  * %pr output the address range in a struct resource with raw flags
1692  * %pM output a 6-byte MAC address with colons
1693  * %pMR output a 6-byte MAC address with colons in reversed order
1694  * %pMF output a 6-byte MAC address with dashes
1695  * %pm output a 6-byte MAC address without colons
1696  * %pmR output a 6-byte MAC address without colons in reversed order
1697  * %pI4 print an IPv4 address without leading zeros
1698  * %pi4 print an IPv4 address with leading zeros
1699  * %pI6 print an IPv6 address with colons
1700  * %pi6 print an IPv6 address without colons
1701  * %pI6c print an IPv6 address as specified by RFC 5952
1702  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1703  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1704  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1705  *   case.
1706  * %*pE[achnops] print an escaped buffer
1707  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1708  *           bytes of the input)
1709  * %n is ignored
1710  *
1711  * ** Please update Documentation/printk-formats.txt when making changes **
1712  *
1713  * The return value is the number of characters which would
1714  * be generated for the given input, excluding the trailing
1715  * '\0', as per ISO C99. If you want to have the exact
1716  * number of characters written into @buf as return value
1717  * (not including the trailing '\0'), use vscnprintf(). If the
1718  * return is greater than or equal to @size, the resulting
1719  * string is truncated.
1720  *
1721  * If you're not already dealing with a va_list consider using snprintf().
1722  */
1723 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1724 {
1725         unsigned long long num;
1726         char *str, *end;
1727         struct printf_spec spec = {0};
1728 
1729         /* Reject out-of-range values early.  Large positive sizes are
1730            used for unknown buffer sizes. */
1731         if (WARN_ON_ONCE((int) size < 0))
1732                 return 0;
1733 
1734         str = buf;
1735         end = buf + size;
1736 
1737         /* Make sure end is always >= buf */
1738         if (end < buf) {
1739                 end = ((void *)-1);
1740                 size = end - buf;
1741         }
1742 
1743         while (*fmt) {
1744                 const char *old_fmt = fmt;
1745                 int read = format_decode(fmt, &spec);
1746 
1747                 fmt += read;
1748 
1749                 switch (spec.type) {
1750                 case FORMAT_TYPE_NONE: {
1751                         int copy = read;
1752                         if (str < end) {
1753                                 if (copy > end - str)
1754                                         copy = end - str;
1755                                 memcpy(str, old_fmt, copy);
1756                         }
1757                         str += read;
1758                         break;
1759                 }
1760 
1761                 case FORMAT_TYPE_WIDTH:
1762                         spec.field_width = va_arg(args, int);
1763                         break;
1764 
1765                 case FORMAT_TYPE_PRECISION:
1766                         spec.precision = va_arg(args, int);
1767                         break;
1768 
1769                 case FORMAT_TYPE_CHAR: {
1770                         char c;
1771 
1772                         if (!(spec.flags & LEFT)) {
1773                                 while (--spec.field_width > 0) {
1774                                         if (str < end)
1775                                                 *str = ' ';
1776                                         ++str;
1777 
1778                                 }
1779                         }
1780                         c = (unsigned char) va_arg(args, int);
1781                         if (str < end)
1782                                 *str = c;
1783                         ++str;
1784                         while (--spec.field_width > 0) {
1785                                 if (str < end)
1786                                         *str = ' ';
1787                                 ++str;
1788                         }
1789                         break;
1790                 }
1791 
1792                 case FORMAT_TYPE_STR:
1793                         str = string(str, end, va_arg(args, char *), spec);
1794                         break;
1795 
1796                 case FORMAT_TYPE_PTR:
1797                         str = pointer(fmt+1, str, end, va_arg(args, void *),
1798                                       spec);
1799                         while (isalnum(*fmt))
1800                                 fmt++;
1801                         break;
1802 
1803                 case FORMAT_TYPE_PERCENT_CHAR:
1804                         if (str < end)
1805                                 *str = '%';
1806                         ++str;
1807                         break;
1808 
1809                 case FORMAT_TYPE_INVALID:
1810                         if (str < end)
1811                                 *str = '%';
1812                         ++str;
1813                         break;
1814 
1815                 default:
1816                         switch (spec.type) {
1817                         case FORMAT_TYPE_LONG_LONG:
1818                                 num = va_arg(args, long long);
1819                                 break;
1820                         case FORMAT_TYPE_ULONG:
1821                                 num = va_arg(args, unsigned long);
1822                                 break;
1823                         case FORMAT_TYPE_LONG:
1824                                 num = va_arg(args, long);
1825                                 break;
1826                         case FORMAT_TYPE_SIZE_T:
1827                                 if (spec.flags & SIGN)
1828                                         num = va_arg(args, ssize_t);
1829                                 else
1830                                         num = va_arg(args, size_t);
1831                                 break;
1832                         case FORMAT_TYPE_PTRDIFF:
1833                                 num = va_arg(args, ptrdiff_t);
1834                                 break;
1835                         case FORMAT_TYPE_UBYTE:
1836                                 num = (unsigned char) va_arg(args, int);
1837                                 break;
1838                         case FORMAT_TYPE_BYTE:
1839                                 num = (signed char) va_arg(args, int);
1840                                 break;
1841                         case FORMAT_TYPE_USHORT:
1842                                 num = (unsigned short) va_arg(args, int);
1843                                 break;
1844                         case FORMAT_TYPE_SHORT:
1845                                 num = (short) va_arg(args, int);
1846                                 break;
1847                         case FORMAT_TYPE_INT:
1848                                 num = (int) va_arg(args, int);
1849                                 break;
1850                         default:
1851                                 num = va_arg(args, unsigned int);
1852                         }
1853 
1854                         str = number(str, end, num, spec);
1855                 }
1856         }
1857 
1858         if (size > 0) {
1859                 if (str < end)
1860                         *str = '\0';
1861                 else
1862                         end[-1] = '\0';
1863         }
1864 
1865         /* the trailing null byte doesn't count towards the total */
1866         return str-buf;
1867 
1868 }
1869 EXPORT_SYMBOL(vsnprintf);
1870 
1871 /**
1872  * vscnprintf - Format a string and place it in a buffer
1873  * @buf: The buffer to place the result into
1874  * @size: The size of the buffer, including the trailing null space
1875  * @fmt: The format string to use
1876  * @args: Arguments for the format string
1877  *
1878  * The return value is the number of characters which have been written into
1879  * the @buf not including the trailing '\0'. If @size is == 0 the function
1880  * returns 0.
1881  *
1882  * If you're not already dealing with a va_list consider using scnprintf().
1883  *
1884  * See the vsnprintf() documentation for format string extensions over C99.
1885  */
1886 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1887 {
1888         int i;
1889 
1890         i = vsnprintf(buf, size, fmt, args);
1891 
1892         if (likely(i < size))
1893                 return i;
1894         if (size != 0)
1895                 return size - 1;
1896         return 0;
1897 }
1898 EXPORT_SYMBOL(vscnprintf);
1899 
1900 /**
1901  * snprintf - Format a string and place it in a buffer
1902  * @buf: The buffer to place the result into
1903  * @size: The size of the buffer, including the trailing null space
1904  * @fmt: The format string to use
1905  * @...: Arguments for the format string
1906  *
1907  * The return value is the number of characters which would be
1908  * generated for the given input, excluding the trailing null,
1909  * as per ISO C99.  If the return is greater than or equal to
1910  * @size, the resulting string is truncated.
1911  *
1912  * See the vsnprintf() documentation for format string extensions over C99.
1913  */
1914 int snprintf(char *buf, size_t size, const char *fmt, ...)
1915 {
1916         va_list args;
1917         int i;
1918 
1919         va_start(args, fmt);
1920         i = vsnprintf(buf, size, fmt, args);
1921         va_end(args);
1922 
1923         return i;
1924 }
1925 EXPORT_SYMBOL(snprintf);
1926 
1927 /**
1928  * scnprintf - Format a string and place it in a buffer
1929  * @buf: The buffer to place the result into
1930  * @size: The size of the buffer, including the trailing null space
1931  * @fmt: The format string to use
1932  * @...: Arguments for the format string
1933  *
1934  * The return value is the number of characters written into @buf not including
1935  * the trailing '\0'. If @size is == 0 the function returns 0.
1936  */
1937 
1938 int scnprintf(char *buf, size_t size, const char *fmt, ...)
1939 {
1940         va_list args;
1941         int i;
1942 
1943         va_start(args, fmt);
1944         i = vscnprintf(buf, size, fmt, args);
1945         va_end(args);
1946 
1947         return i;
1948 }
1949 EXPORT_SYMBOL(scnprintf);
1950 
1951 /**
1952  * vsprintf - Format a string and place it in a buffer
1953  * @buf: The buffer to place the result into
1954  * @fmt: The format string to use
1955  * @args: Arguments for the format string
1956  *
1957  * The function returns the number of characters written
1958  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1959  * buffer overflows.
1960  *
1961  * If you're not already dealing with a va_list consider using sprintf().
1962  *
1963  * See the vsnprintf() documentation for format string extensions over C99.
1964  */
1965 int vsprintf(char *buf, const char *fmt, va_list args)
1966 {
1967         return vsnprintf(buf, INT_MAX, fmt, args);
1968 }
1969 EXPORT_SYMBOL(vsprintf);
1970 
1971 /**
1972  * sprintf - Format a string and place it in a buffer
1973  * @buf: The buffer to place the result into
1974  * @fmt: The format string to use
1975  * @...: Arguments for the format string
1976  *
1977  * The function returns the number of characters written
1978  * into @buf. Use snprintf() or scnprintf() in order to avoid
1979  * buffer overflows.
1980  *
1981  * See the vsnprintf() documentation for format string extensions over C99.
1982  */
1983 int sprintf(char *buf, const char *fmt, ...)
1984 {
1985         va_list args;
1986         int i;
1987 
1988         va_start(args, fmt);
1989         i = vsnprintf(buf, INT_MAX, fmt, args);
1990         va_end(args);
1991 
1992         return i;
1993 }
1994 EXPORT_SYMBOL(sprintf);
1995 
1996 #ifdef CONFIG_BINARY_PRINTF
1997 /*
1998  * bprintf service:
1999  * vbin_printf() - VA arguments to binary data
2000  * bstr_printf() - Binary data to text string
2001  */
2002 
2003 /**
2004  * vbin_printf - Parse a format string and place args' binary value in a buffer
2005  * @bin_buf: The buffer to place args' binary value
2006  * @size: The size of the buffer(by words(32bits), not characters)
2007  * @fmt: The format string to use
2008  * @args: Arguments for the format string
2009  *
2010  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2011  * is skipped.
2012  *
2013  * The return value is the number of words(32bits) which would be generated for
2014  * the given input.
2015  *
2016  * NOTE:
2017  * If the return value is greater than @size, the resulting bin_buf is NOT
2018  * valid for bstr_printf().
2019  */
2020 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2021 {
2022         struct printf_spec spec = {0};
2023         char *str, *end;
2024 
2025         str = (char *)bin_buf;
2026         end = (char *)(bin_buf + size);
2027 
2028 #define save_arg(type)                                                  \
2029 do {                                                                    \
2030         if (sizeof(type) == 8) {                                        \
2031                 unsigned long long value;                               \
2032                 str = PTR_ALIGN(str, sizeof(u32));                      \
2033                 value = va_arg(args, unsigned long long);               \
2034                 if (str + sizeof(type) <= end) {                        \
2035                         *(u32 *)str = *(u32 *)&value;                   \
2036                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
2037                 }                                                       \
2038         } else {                                                        \
2039                 unsigned long value;                                    \
2040                 str = PTR_ALIGN(str, sizeof(type));                     \
2041                 value = va_arg(args, int);                              \
2042                 if (str + sizeof(type) <= end)                          \
2043                         *(typeof(type) *)str = (type)value;             \
2044         }                                                               \
2045         str += sizeof(type);                                            \
2046 } while (0)
2047 
2048         while (*fmt) {
2049                 int read = format_decode(fmt, &spec);
2050 
2051                 fmt += read;
2052 
2053                 switch (spec.type) {
2054                 case FORMAT_TYPE_NONE:
2055                 case FORMAT_TYPE_INVALID:
2056                 case FORMAT_TYPE_PERCENT_CHAR:
2057                         break;
2058 
2059                 case FORMAT_TYPE_WIDTH:
2060                 case FORMAT_TYPE_PRECISION:
2061                         save_arg(int);
2062                         break;
2063 
2064                 case FORMAT_TYPE_CHAR:
2065                         save_arg(char);
2066                         break;
2067 
2068                 case FORMAT_TYPE_STR: {
2069                         const char *save_str = va_arg(args, char *);
2070                         size_t len;
2071 
2072                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2073                                         || (unsigned long)save_str < PAGE_SIZE)
2074                                 save_str = "(null)";
2075                         len = strlen(save_str) + 1;
2076                         if (str + len < end)
2077                                 memcpy(str, save_str, len);
2078                         str += len;
2079                         break;
2080                 }
2081 
2082                 case FORMAT_TYPE_PTR:
2083                         save_arg(void *);
2084                         /* skip all alphanumeric pointer suffixes */
2085                         while (isalnum(*fmt))
2086                                 fmt++;
2087                         break;
2088 
2089                 default:
2090                         switch (spec.type) {
2091 
2092                         case FORMAT_TYPE_LONG_LONG:
2093                                 save_arg(long long);
2094                                 break;
2095                         case FORMAT_TYPE_ULONG:
2096                         case FORMAT_TYPE_LONG:
2097                                 save_arg(unsigned long);
2098                                 break;
2099                         case FORMAT_TYPE_SIZE_T:
2100                                 save_arg(size_t);
2101                                 break;
2102                         case FORMAT_TYPE_PTRDIFF:
2103                                 save_arg(ptrdiff_t);
2104                                 break;
2105                         case FORMAT_TYPE_UBYTE:
2106                         case FORMAT_TYPE_BYTE:
2107                                 save_arg(char);
2108                                 break;
2109                         case FORMAT_TYPE_USHORT:
2110                         case FORMAT_TYPE_SHORT:
2111                                 save_arg(short);
2112                                 break;
2113                         default:
2114                                 save_arg(int);
2115                         }
2116                 }
2117         }
2118 
2119         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2120 #undef save_arg
2121 }
2122 EXPORT_SYMBOL_GPL(vbin_printf);
2123 
2124 /**
2125  * bstr_printf - Format a string from binary arguments and place it in a buffer
2126  * @buf: The buffer to place the result into
2127  * @size: The size of the buffer, including the trailing null space
2128  * @fmt: The format string to use
2129  * @bin_buf: Binary arguments for the format string
2130  *
2131  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2132  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2133  * a binary buffer that generated by vbin_printf.
2134  *
2135  * The format follows C99 vsnprintf, but has some extensions:
2136  *  see vsnprintf comment for details.
2137  *
2138  * The return value is the number of characters which would
2139  * be generated for the given input, excluding the trailing
2140  * '\0', as per ISO C99. If you want to have the exact
2141  * number of characters written into @buf as return value
2142  * (not including the trailing '\0'), use vscnprintf(). If the
2143  * return is greater than or equal to @size, the resulting
2144  * string is truncated.
2145  */
2146 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2147 {
2148         struct printf_spec spec = {0};
2149         char *str, *end;
2150         const char *args = (const char *)bin_buf;
2151 
2152         if (WARN_ON_ONCE((int) size < 0))
2153                 return 0;
2154 
2155         str = buf;
2156         end = buf + size;
2157 
2158 #define get_arg(type)                                                   \
2159 ({                                                                      \
2160         typeof(type) value;                                             \
2161         if (sizeof(type) == 8) {                                        \
2162                 args = PTR_ALIGN(args, sizeof(u32));                    \
2163                 *(u32 *)&value = *(u32 *)args;                          \
2164                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2165         } else {                                                        \
2166                 args = PTR_ALIGN(args, sizeof(type));                   \
2167                 value = *(typeof(type) *)args;                          \
2168         }                                                               \
2169         args += sizeof(type);                                           \
2170         value;                                                          \
2171 })
2172 
2173         /* Make sure end is always >= buf */
2174         if (end < buf) {
2175                 end = ((void *)-1);
2176                 size = end - buf;
2177         }
2178 
2179         while (*fmt) {
2180                 const char *old_fmt = fmt;
2181                 int read = format_decode(fmt, &spec);
2182 
2183                 fmt += read;
2184 
2185                 switch (spec.type) {
2186                 case FORMAT_TYPE_NONE: {
2187                         int copy = read;
2188                         if (str < end) {
2189                                 if (copy > end - str)
2190                                         copy = end - str;
2191                                 memcpy(str, old_fmt, copy);
2192                         }
2193                         str += read;
2194                         break;
2195                 }
2196 
2197                 case FORMAT_TYPE_WIDTH:
2198                         spec.field_width = get_arg(int);
2199                         break;
2200 
2201                 case FORMAT_TYPE_PRECISION:
2202                         spec.precision = get_arg(int);
2203                         break;
2204 
2205                 case FORMAT_TYPE_CHAR: {
2206                         char c;
2207 
2208                         if (!(spec.flags & LEFT)) {
2209                                 while (--spec.field_width > 0) {
2210                                         if (str < end)
2211                                                 *str = ' ';
2212                                         ++str;
2213                                 }
2214                         }
2215                         c = (unsigned char) get_arg(char);
2216                         if (str < end)
2217                                 *str = c;
2218                         ++str;
2219                         while (--spec.field_width > 0) {
2220                                 if (str < end)
2221                                         *str = ' ';
2222                                 ++str;
2223                         }
2224                         break;
2225                 }
2226 
2227                 case FORMAT_TYPE_STR: {
2228                         const char *str_arg = args;
2229                         args += strlen(str_arg) + 1;
2230                         str = string(str, end, (char *)str_arg, spec);
2231                         break;
2232                 }
2233 
2234                 case FORMAT_TYPE_PTR:
2235                         str = pointer(fmt+1, str, end, get_arg(void *), spec);
2236                         while (isalnum(*fmt))
2237                                 fmt++;
2238                         break;
2239 
2240                 case FORMAT_TYPE_PERCENT_CHAR:
2241                 case FORMAT_TYPE_INVALID:
2242                         if (str < end)
2243                                 *str = '%';
2244                         ++str;
2245                         break;
2246 
2247                 default: {
2248                         unsigned long long num;
2249 
2250                         switch (spec.type) {
2251 
2252                         case FORMAT_TYPE_LONG_LONG:
2253                                 num = get_arg(long long);
2254                                 break;
2255                         case FORMAT_TYPE_ULONG:
2256                         case FORMAT_TYPE_LONG:
2257                                 num = get_arg(unsigned long);
2258                                 break;
2259                         case FORMAT_TYPE_SIZE_T:
2260                                 num = get_arg(size_t);
2261                                 break;
2262                         case FORMAT_TYPE_PTRDIFF:
2263                                 num = get_arg(ptrdiff_t);
2264                                 break;
2265                         case FORMAT_TYPE_UBYTE:
2266                                 num = get_arg(unsigned char);
2267                                 break;
2268                         case FORMAT_TYPE_BYTE:
2269                                 num = get_arg(signed char);
2270                                 break;
2271                         case FORMAT_TYPE_USHORT:
2272                                 num = get_arg(unsigned short);
2273                                 break;
2274                         case FORMAT_TYPE_SHORT:
2275                                 num = get_arg(short);
2276                                 break;
2277                         case FORMAT_TYPE_UINT:
2278                                 num = get_arg(unsigned int);
2279                                 break;
2280                         default:
2281                                 num = get_arg(int);
2282                         }
2283 
2284                         str = number(str, end, num, spec);
2285                 } /* default: */
2286                 } /* switch(spec.type) */
2287         } /* while(*fmt) */
2288 
2289         if (size > 0) {
2290                 if (str < end)
2291                         *str = '\0';
2292                 else
2293                         end[-1] = '\0';
2294         }
2295 
2296 #undef get_arg
2297 
2298         /* the trailing null byte doesn't count towards the total */
2299         return str - buf;
2300 }
2301 EXPORT_SYMBOL_GPL(bstr_printf);
2302 
2303 /**
2304  * bprintf - Parse a format string and place args' binary value in a buffer
2305  * @bin_buf: The buffer to place args' binary value
2306  * @size: The size of the buffer(by words(32bits), not characters)
2307  * @fmt: The format string to use
2308  * @...: Arguments for the format string
2309  *
2310  * The function returns the number of words(u32) written
2311  * into @bin_buf.
2312  */
2313 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2314 {
2315         va_list args;
2316         int ret;
2317 
2318         va_start(args, fmt);
2319         ret = vbin_printf(bin_buf, size, fmt, args);
2320         va_end(args);
2321 
2322         return ret;
2323 }
2324 EXPORT_SYMBOL_GPL(bprintf);
2325 
2326 #endif /* CONFIG_BINARY_PRINTF */
2327 
2328 /**
2329  * vsscanf - Unformat a buffer into a list of arguments
2330  * @buf:        input buffer
2331  * @fmt:        format of buffer
2332  * @args:       arguments
2333  */
2334 int vsscanf(const char *buf, const char *fmt, va_list args)
2335 {
2336         const char *str = buf;
2337         char *next;
2338         char digit;
2339         int num = 0;
2340         u8 qualifier;
2341         unsigned int base;
2342         union {
2343                 long long s;
2344                 unsigned long long u;
2345         } val;
2346         s16 field_width;
2347         bool is_sign;
2348 
2349         while (*fmt) {
2350                 /* skip any white space in format */
2351                 /* white space in format matchs any amount of
2352                  * white space, including none, in the input.
2353                  */
2354                 if (isspace(*fmt)) {
2355                         fmt = skip_spaces(++fmt);
2356                         str = skip_spaces(str);
2357                 }
2358 
2359                 /* anything that is not a conversion must match exactly */
2360                 if (*fmt != '%' && *fmt) {
2361                         if (*fmt++ != *str++)
2362                                 break;
2363                         continue;
2364                 }
2365 
2366                 if (!*fmt)
2367                         break;
2368                 ++fmt;
2369 
2370                 /* skip this conversion.
2371                  * advance both strings to next white space
2372                  */
2373                 if (*fmt == '*') {
2374                         if (!*str)
2375                                 break;
2376                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
2377                                 fmt++;
2378                         while (!isspace(*str) && *str)
2379                                 str++;
2380                         continue;
2381                 }
2382 
2383                 /* get field width */
2384                 field_width = -1;
2385                 if (isdigit(*fmt)) {
2386                         field_width = skip_atoi(&fmt);
2387                         if (field_width <= 0)
2388                                 break;
2389                 }
2390 
2391                 /* get conversion qualifier */
2392                 qualifier = -1;
2393                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2394                     _tolower(*fmt) == 'z') {
2395                         qualifier = *fmt++;
2396                         if (unlikely(qualifier == *fmt)) {
2397                                 if (qualifier == 'h') {
2398                                         qualifier = 'H';
2399                                         fmt++;
2400                                 } else if (qualifier == 'l') {
2401                                         qualifier = 'L';
2402                                         fmt++;
2403                                 }
2404                         }
2405                 }
2406 
2407                 if (!*fmt)
2408                         break;
2409 
2410                 if (*fmt == 'n') {
2411                         /* return number of characters read so far */
2412                         *va_arg(args, int *) = str - buf;
2413                         ++fmt;
2414                         continue;
2415                 }
2416 
2417                 if (!*str)
2418                         break;
2419 
2420                 base = 10;
2421                 is_sign = false;
2422 
2423                 switch (*fmt++) {
2424                 case 'c':
2425                 {
2426                         char *s = (char *)va_arg(args, char*);
2427                         if (field_width == -1)
2428                                 field_width = 1;
2429                         do {
2430                                 *s++ = *str++;
2431                         } while (--field_width > 0 && *str);
2432                         num++;
2433                 }
2434                 continue;
2435                 case 's':
2436                 {
2437                         char *s = (char *)va_arg(args, char *);
2438                         if (field_width == -1)
2439                                 field_width = SHRT_MAX;
2440                         /* first, skip leading white space in buffer */
2441                         str = skip_spaces(str);
2442 
2443                         /* now copy until next white space */
2444                         while (*str && !isspace(*str) && field_width--)
2445                                 *s++ = *str++;
2446                         *s = '\0';
2447                         num++;
2448                 }
2449                 continue;
2450                 case 'o':
2451                         base = 8;
2452                         break;
2453                 case 'x':
2454                 case 'X':
2455                         base = 16;
2456                         break;
2457                 case 'i':
2458                         base = 0;
2459                 case 'd':
2460                         is_sign = true;
2461                 case 'u':
2462                         break;
2463                 case '%':
2464                         /* looking for '%' in str */
2465                         if (*str++ != '%')
2466                                 return num;
2467                         continue;
2468                 default:
2469                         /* invalid format; stop here */
2470                         return num;
2471                 }
2472 
2473                 /* have some sort of integer conversion.
2474                  * first, skip white space in buffer.
2475                  */
2476                 str = skip_spaces(str);
2477 
2478                 digit = *str;
2479                 if (is_sign && digit == '-')
2480                         digit = *(str + 1);
2481 
2482                 if (!digit
2483                     || (base == 16 && !isxdigit(digit))
2484                     || (base == 10 && !isdigit(digit))
2485                     || (base == 8 && (!isdigit(digit) || digit > '7'))
2486                     || (base == 0 && !isdigit(digit)))
2487                         break;
2488 
2489                 if (is_sign)
2490                         val.s = qualifier != 'L' ?
2491                                 simple_strtol(str, &next, base) :
2492                                 simple_strtoll(str, &next, base);
2493                 else
2494                         val.u = qualifier != 'L' ?
2495                                 simple_strtoul(str, &next, base) :
2496                                 simple_strtoull(str, &next, base);
2497 
2498                 if (field_width > 0 && next - str > field_width) {
2499                         if (base == 0)
2500                                 _parse_integer_fixup_radix(str, &base);
2501                         while (next - str > field_width) {
2502                                 if (is_sign)
2503                                         val.s = div_s64(val.s, base);
2504                                 else
2505                                         val.u = div_u64(val.u, base);
2506                                 --next;
2507                         }
2508                 }
2509 
2510                 switch (qualifier) {
2511                 case 'H':       /* that's 'hh' in format */
2512                         if (is_sign)
2513                                 *va_arg(args, signed char *) = val.s;
2514                         else
2515                                 *va_arg(args, unsigned char *) = val.u;
2516                         break;
2517                 case 'h':
2518                         if (is_sign)
2519                                 *va_arg(args, short *) = val.s;
2520                         else
2521                                 *va_arg(args, unsigned short *) = val.u;
2522                         break;
2523                 case 'l':
2524                         if (is_sign)
2525                                 *va_arg(args, long *) = val.s;
2526                         else
2527                                 *va_arg(args, unsigned long *) = val.u;
2528                         break;
2529                 case 'L':
2530                         if (is_sign)
2531                                 *va_arg(args, long long *) = val.s;
2532                         else
2533                                 *va_arg(args, unsigned long long *) = val.u;
2534                         break;
2535                 case 'Z':
2536                 case 'z':
2537                         *va_arg(args, size_t *) = val.u;
2538                         break;
2539                 default:
2540                         if (is_sign)
2541                                 *va_arg(args, int *) = val.s;
2542                         else
2543                                 *va_arg(args, unsigned int *) = val.u;
2544                         break;
2545                 }
2546                 num++;
2547 
2548                 if (!next)
2549                         break;
2550                 str = next;
2551         }
2552 
2553         return num;
2554 }
2555 EXPORT_SYMBOL(vsscanf);
2556 
2557 /**
2558  * sscanf - Unformat a buffer into a list of arguments
2559  * @buf:        input buffer
2560  * @fmt:        formatting of buffer
2561  * @...:        resulting arguments
2562  */
2563 int sscanf(const char *buf, const char *fmt, ...)
2564 {
2565         va_list args;
2566         int i;
2567 
2568         va_start(args, fmt);
2569         i = vsscanf(buf, fmt, args);
2570         va_end(args);
2571 
2572         return i;
2573 }
2574 EXPORT_SYMBOL(sscanf);
2575 

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