Version:  2.6.34 2.6.35 2.6.36 2.6.37 2.6.38 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14

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 44  * This function is obsolete.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 69  * This function is obsolete.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 83  * This function is obsolete.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100  * This function is obsolete.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

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us