Version:  2.0.40 2.2.26 2.4.37 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0

Linux/lib/vsprintf.c

  1 /*
  2  *  linux/lib/vsprintf.c
  3  *
  4  *  Copyright (C) 1991, 1992  Linus Torvalds
  5  */
  6 
  7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
  8 /*
  9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
 10  */
 11 
 12 /*
 13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
 14  * - changed to provide snprintf and vsnprintf functions
 15  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
 16  * - scnprintf and vscnprintf
 17  */
 18 
 19 #include <stdarg.h>
 20 #include <linux/module.h>       /* for KSYM_SYMBOL_LEN */
 21 #include <linux/types.h>
 22 #include <linux/string.h>
 23 #include <linux/ctype.h>
 24 #include <linux/kernel.h>
 25 #include <linux/kallsyms.h>
 26 #include <linux/math64.h>
 27 #include <linux/uaccess.h>
 28 #include <linux/ioport.h>
 29 #include <linux/dcache.h>
 30 #include <linux/cred.h>
 31 #include <net/addrconf.h>
 32 
 33 #include <asm/page.h>           /* for PAGE_SIZE */
 34 #include <asm/sections.h>       /* for dereference_function_descriptor() */
 35 
 36 #include <linux/string_helpers.h>
 37 #include "kstrtox.h"
 38 
 39 /**
 40  * simple_strtoull - convert a string to an unsigned long long
 41  * @cp: The start of the string
 42  * @endp: A pointer to the end of the parsed string will be placed here
 43  * @base: The number base to use
 44  *
 45  * This function is obsolete. Please use kstrtoull instead.
 46  */
 47 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 48 {
 49         unsigned long long result;
 50         unsigned int rv;
 51 
 52         cp = _parse_integer_fixup_radix(cp, &base);
 53         rv = _parse_integer(cp, base, &result);
 54         /* FIXME */
 55         cp += (rv & ~KSTRTOX_OVERFLOW);
 56 
 57         if (endp)
 58                 *endp = (char *)cp;
 59 
 60         return result;
 61 }
 62 EXPORT_SYMBOL(simple_strtoull);
 63 
 64 /**
 65  * simple_strtoul - convert a string to an unsigned long
 66  * @cp: The start of the string
 67  * @endp: A pointer to the end of the parsed string will be placed here
 68  * @base: The number base to use
 69  *
 70  * This function is obsolete. Please use kstrtoul instead.
 71  */
 72 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
 73 {
 74         return simple_strtoull(cp, endp, base);
 75 }
 76 EXPORT_SYMBOL(simple_strtoul);
 77 
 78 /**
 79  * simple_strtol - convert a string to a signed long
 80  * @cp: The start of the string
 81  * @endp: A pointer to the end of the parsed string will be placed here
 82  * @base: The number base to use
 83  *
 84  * This function is obsolete. Please use kstrtol instead.
 85  */
 86 long simple_strtol(const char *cp, char **endp, unsigned int base)
 87 {
 88         if (*cp == '-')
 89                 return -simple_strtoul(cp + 1, endp, base);
 90 
 91         return simple_strtoul(cp, endp, base);
 92 }
 93 EXPORT_SYMBOL(simple_strtol);
 94 
 95 /**
 96  * simple_strtoll - convert a string to a signed long long
 97  * @cp: The start of the string
 98  * @endp: A pointer to the end of the parsed string will be placed here
 99  * @base: The number base to use
100  *
101  * This function is obsolete. Please use kstrtoll instead.
102  */
103 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
104 {
105         if (*cp == '-')
106                 return -simple_strtoull(cp + 1, endp, base);
107 
108         return simple_strtoull(cp, endp, base);
109 }
110 EXPORT_SYMBOL(simple_strtoll);
111 
112 static noinline_for_stack
113 int skip_atoi(const char **s)
114 {
115         int i = 0;
116 
117         do {
118                 i = i*10 + *((*s)++) - '';
119         } while (isdigit(**s));
120 
121         return i;
122 }
123 
124 /* Decimal conversion is by far the most typical, and is used
125  * for /proc and /sys data. This directly impacts e.g. top performance
126  * with many processes running. We optimize it for speed
127  * using ideas described at <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
128  * (with permission from the author, Douglas W. Jones).
129  */
130 
131 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
132 /* Formats correctly any integer in [0, 999999999] */
133 static noinline_for_stack
134 char *put_dec_full9(char *buf, unsigned q)
135 {
136         unsigned r;
137 
138         /*
139          * Possible ways to approx. divide by 10
140          * (x * 0x1999999a) >> 32 x < 1073741829 (multiply must be 64-bit)
141          * (x * 0xcccd) >> 19     x <      81920 (x < 262149 when 64-bit mul)
142          * (x * 0x6667) >> 18     x <      43699
143          * (x * 0x3334) >> 17     x <      16389
144          * (x * 0x199a) >> 16     x <      16389
145          * (x * 0x0ccd) >> 15     x <      16389
146          * (x * 0x0667) >> 14     x <       2739
147          * (x * 0x0334) >> 13     x <       1029
148          * (x * 0x019a) >> 12     x <       1029
149          * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)
150          * (x * 0x0067) >> 10     x <        179
151          * (x * 0x0034) >>  9     x <         69 same
152          * (x * 0x001a) >>  8     x <         69 same
153          * (x * 0x000d) >>  7     x <         69 same, shortest code (on i386)
154          * (x * 0x0007) >>  6     x <         19
155          * See <http://www.cs.uiowa.edu/~jones/bcd/divide.html>
156          */
157         r      = (q * (uint64_t)0x1999999a) >> 32;
158         *buf++ = (q - 10 * r) + ''; /* 1 */
159         q      = (r * (uint64_t)0x1999999a) >> 32;
160         *buf++ = (r - 10 * q) + ''; /* 2 */
161         r      = (q * (uint64_t)0x1999999a) >> 32;
162         *buf++ = (q - 10 * r) + ''; /* 3 */
163         q      = (r * (uint64_t)0x1999999a) >> 32;
164         *buf++ = (r - 10 * q) + ''; /* 4 */
165         r      = (q * (uint64_t)0x1999999a) >> 32;
166         *buf++ = (q - 10 * r) + ''; /* 5 */
167         /* Now value is under 10000, can avoid 64-bit multiply */
168         q      = (r * 0x199a) >> 16;
169         *buf++ = (r - 10 * q)  + ''; /* 6 */
170         r      = (q * 0xcd) >> 11;
171         *buf++ = (q - 10 * r)  + ''; /* 7 */
172         q      = (r * 0xcd) >> 11;
173         *buf++ = (r - 10 * q) + ''; /* 8 */
174         *buf++ = q + ''; /* 9 */
175         return buf;
176 }
177 #endif
178 
179 /* Similar to above but do not pad with zeros.
180  * Code can be easily arranged to print 9 digits too, but our callers
181  * always call put_dec_full9() instead when the number has 9 decimal digits.
182  */
183 static noinline_for_stack
184 char *put_dec_trunc8(char *buf, unsigned r)
185 {
186         unsigned q;
187 
188         /* Copy of previous function's body with added early returns */
189         while (r >= 10000) {
190                 q = r + '';
191                 r  = (r * (uint64_t)0x1999999a) >> 32;
192                 *buf++ = q - 10*r;
193         }
194 
195         q      = (r * 0x199a) >> 16;    /* r <= 9999 */
196         *buf++ = (r - 10 * q)  + '';
197         if (q == 0)
198                 return buf;
199         r      = (q * 0xcd) >> 11;      /* q <= 999 */
200         *buf++ = (q - 10 * r)  + '';
201         if (r == 0)
202                 return buf;
203         q      = (r * 0xcd) >> 11;      /* r <= 99 */
204         *buf++ = (r - 10 * q) + '';
205         if (q == 0)
206                 return buf;
207         *buf++ = q + '';                /* q <= 9 */
208         return buf;
209 }
210 
211 /* There are two algorithms to print larger numbers.
212  * One is generic: divide by 1000000000 and repeatedly print
213  * groups of (up to) 9 digits. It's conceptually simple,
214  * but requires a (unsigned long long) / 1000000000 division.
215  *
216  * Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
217  * manipulates them cleverly and generates groups of 4 decimal digits.
218  * It so happens that it does NOT require long long division.
219  *
220  * If long is > 32 bits, division of 64-bit values is relatively easy,
221  * and we will use the first algorithm.
222  * If long long is > 64 bits (strange architecture with VERY large long long),
223  * second algorithm can't be used, and we again use the first one.
224  *
225  * Else (if long is 32 bits and long long is 64 bits) we use second one.
226  */
227 
228 #if BITS_PER_LONG != 32 || BITS_PER_LONG_LONG != 64
229 
230 /* First algorithm: generic */
231 
232 static
233 char *put_dec(char *buf, unsigned long long n)
234 {
235         if (n >= 100*1000*1000) {
236                 while (n >= 1000*1000*1000)
237                         buf = put_dec_full9(buf, do_div(n, 1000*1000*1000));
238                 if (n >= 100*1000*1000)
239                         return put_dec_full9(buf, n);
240         }
241         return put_dec_trunc8(buf, n);
242 }
243 
244 #else
245 
246 /* Second algorithm: valid only for 64-bit long longs */
247 
248 /* See comment in put_dec_full9 for choice of constants */
249 static noinline_for_stack
250 void put_dec_full4(char *buf, unsigned q)
251 {
252         unsigned r;
253         r      = (q * 0xccd) >> 15;
254         buf[0] = (q - 10 * r) + '';
255         q      = (r * 0xcd) >> 11;
256         buf[1] = (r - 10 * q)  + '';
257         r      = (q * 0xcd) >> 11;
258         buf[2] = (q - 10 * r)  + '';
259         buf[3] = r + '';
260 }
261 
262 /*
263  * Call put_dec_full4 on x % 10000, return x / 10000.
264  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
265  * holds for all x < 1,128,869,999.  The largest value this
266  * helper will ever be asked to convert is 1,125,520,955.
267  * (d1 in the put_dec code, assuming n is all-ones).
268  */
269 static
270 unsigned put_dec_helper4(char *buf, unsigned x)
271 {
272         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
273 
274         put_dec_full4(buf, x - q * 10000);
275         return q;
276 }
277 
278 /* Based on code by Douglas W. Jones found at
279  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
280  * (with permission from the author).
281  * Performs no 64-bit division and hence should be fast on 32-bit machines.
282  */
283 static
284 char *put_dec(char *buf, unsigned long long n)
285 {
286         uint32_t d3, d2, d1, q, h;
287 
288         if (n < 100*1000*1000)
289                 return put_dec_trunc8(buf, n);
290 
291         d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
292         h   = (n >> 32);
293         d2  = (h      ) & 0xffff;
294         d3  = (h >> 16); /* implicit "& 0xffff" */
295 
296         q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
297         q = put_dec_helper4(buf, q);
298 
299         q += 7671 * d3 + 9496 * d2 + 6 * d1;
300         q = put_dec_helper4(buf+4, q);
301 
302         q += 4749 * d3 + 42 * d2;
303         q = put_dec_helper4(buf+8, q);
304 
305         q += 281 * d3;
306         buf += 12;
307         if (q)
308                 buf = put_dec_trunc8(buf, q);
309         else while (buf[-1] == '')
310                 --buf;
311 
312         return buf;
313 }
314 
315 #endif
316 
317 /*
318  * Convert passed number to decimal string.
319  * Returns the length of string.  On buffer overflow, returns 0.
320  *
321  * If speed is not important, use snprintf(). It's easy to read the code.
322  */
323 int num_to_str(char *buf, int size, unsigned long long num)
324 {
325         char tmp[sizeof(num) * 3];
326         int idx, len;
327 
328         /* put_dec() may work incorrectly for num = 0 (generate "", not "") */
329         if (num <= 9) {
330                 tmp[0] = '' + num;
331                 len = 1;
332         } else {
333                 len = put_dec(tmp, num) - tmp;
334         }
335 
336         if (len > size)
337                 return 0;
338         for (idx = 0; idx < len; ++idx)
339                 buf[idx] = tmp[len - idx - 1];
340         return len;
341 }
342 
343 #define ZEROPAD 1               /* pad with zero */
344 #define SIGN    2               /* unsigned/signed long */
345 #define PLUS    4               /* show plus */
346 #define SPACE   8               /* space if plus */
347 #define LEFT    16              /* left justified */
348 #define SMALL   32              /* use lowercase in hex (must be 32 == 0x20) */
349 #define SPECIAL 64              /* prefix hex with "0x", octal with "" */
350 
351 enum format_type {
352         FORMAT_TYPE_NONE, /* Just a string part */
353         FORMAT_TYPE_WIDTH,
354         FORMAT_TYPE_PRECISION,
355         FORMAT_TYPE_CHAR,
356         FORMAT_TYPE_STR,
357         FORMAT_TYPE_PTR,
358         FORMAT_TYPE_PERCENT_CHAR,
359         FORMAT_TYPE_INVALID,
360         FORMAT_TYPE_LONG_LONG,
361         FORMAT_TYPE_ULONG,
362         FORMAT_TYPE_LONG,
363         FORMAT_TYPE_UBYTE,
364         FORMAT_TYPE_BYTE,
365         FORMAT_TYPE_USHORT,
366         FORMAT_TYPE_SHORT,
367         FORMAT_TYPE_UINT,
368         FORMAT_TYPE_INT,
369         FORMAT_TYPE_SIZE_T,
370         FORMAT_TYPE_PTRDIFF
371 };
372 
373 struct printf_spec {
374         u8      type;           /* format_type enum */
375         u8      flags;          /* flags to number() */
376         u8      base;           /* number base, 8, 10 or 16 only */
377         u8      qualifier;      /* number qualifier, one of 'hHlLtzZ' */
378         s16     field_width;    /* width of output field */
379         s16     precision;      /* # of digits/chars */
380 };
381 
382 static noinline_for_stack
383 char *number(char *buf, char *end, unsigned long long num,
384              struct printf_spec spec)
385 {
386         /* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
387         static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
388 
389         char tmp[66];
390         char sign;
391         char locase;
392         int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
393         int i;
394         bool is_zero = num == 0LL;
395 
396         /* locase = 0 or 0x20. ORing digits or letters with 'locase'
397          * produces same digits or (maybe lowercased) letters */
398         locase = (spec.flags & SMALL);
399         if (spec.flags & LEFT)
400                 spec.flags &= ~ZEROPAD;
401         sign = 0;
402         if (spec.flags & SIGN) {
403                 if ((signed long long)num < 0) {
404                         sign = '-';
405                         num = -(signed long long)num;
406                         spec.field_width--;
407                 } else if (spec.flags & PLUS) {
408                         sign = '+';
409                         spec.field_width--;
410                 } else if (spec.flags & SPACE) {
411                         sign = ' ';
412                         spec.field_width--;
413                 }
414         }
415         if (need_pfx) {
416                 if (spec.base == 16)
417                         spec.field_width -= 2;
418                 else if (!is_zero)
419                         spec.field_width--;
420         }
421 
422         /* generate full string in tmp[], in reverse order */
423         i = 0;
424         if (num < spec.base)
425                 tmp[i++] = digits[num] | locase;
426         /* Generic code, for any base:
427         else do {
428                 tmp[i++] = (digits[do_div(num,base)] | locase);
429         } while (num != 0);
430         */
431         else if (spec.base != 10) { /* 8 or 16 */
432                 int mask = spec.base - 1;
433                 int shift = 3;
434 
435                 if (spec.base == 16)
436                         shift = 4;
437                 do {
438                         tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
439                         num >>= shift;
440                 } while (num);
441         } else { /* base 10 */
442                 i = put_dec(tmp, num) - tmp;
443         }
444 
445         /* printing 100 using %2d gives "100", not "00" */
446         if (i > spec.precision)
447                 spec.precision = i;
448         /* leading space padding */
449         spec.field_width -= spec.precision;
450         if (!(spec.flags & (ZEROPAD+LEFT))) {
451                 while (--spec.field_width >= 0) {
452                         if (buf < end)
453                                 *buf = ' ';
454                         ++buf;
455                 }
456         }
457         /* sign */
458         if (sign) {
459                 if (buf < end)
460                         *buf = sign;
461                 ++buf;
462         }
463         /* "0x" / "" prefix */
464         if (need_pfx) {
465                 if (spec.base == 16 || !is_zero) {
466                         if (buf < end)
467                                 *buf = '';
468                         ++buf;
469                 }
470                 if (spec.base == 16) {
471                         if (buf < end)
472                                 *buf = ('X' | locase);
473                         ++buf;
474                 }
475         }
476         /* zero or space padding */
477         if (!(spec.flags & LEFT)) {
478                 char c = (spec.flags & ZEROPAD) ? '' : ' ';
479                 while (--spec.field_width >= 0) {
480                         if (buf < end)
481                                 *buf = c;
482                         ++buf;
483                 }
484         }
485         /* hmm even more zero padding? */
486         while (i <= --spec.precision) {
487                 if (buf < end)
488                         *buf = '';
489                 ++buf;
490         }
491         /* actual digits of result */
492         while (--i >= 0) {
493                 if (buf < end)
494                         *buf = tmp[i];
495                 ++buf;
496         }
497         /* trailing space padding */
498         while (--spec.field_width >= 0) {
499                 if (buf < end)
500                         *buf = ' ';
501                 ++buf;
502         }
503 
504         return buf;
505 }
506 
507 static noinline_for_stack
508 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
509 {
510         int len, i;
511 
512         if ((unsigned long)s < PAGE_SIZE)
513                 s = "(null)";
514 
515         len = strnlen(s, spec.precision);
516 
517         if (!(spec.flags & LEFT)) {
518                 while (len < spec.field_width--) {
519                         if (buf < end)
520                                 *buf = ' ';
521                         ++buf;
522                 }
523         }
524         for (i = 0; i < len; ++i) {
525                 if (buf < end)
526                         *buf = *s;
527                 ++buf; ++s;
528         }
529         while (len < spec.field_width--) {
530                 if (buf < end)
531                         *buf = ' ';
532                 ++buf;
533         }
534 
535         return buf;
536 }
537 
538 static void widen(char *buf, char *end, unsigned len, unsigned spaces)
539 {
540         size_t size;
541         if (buf >= end) /* nowhere to put anything */
542                 return;
543         size = end - buf;
544         if (size <= spaces) {
545                 memset(buf, ' ', size);
546                 return;
547         }
548         if (len) {
549                 if (len > size - spaces)
550                         len = size - spaces;
551                 memmove(buf + spaces, buf, len);
552         }
553         memset(buf, ' ', spaces);
554 }
555 
556 static noinline_for_stack
557 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
558                   const char *fmt)
559 {
560         const char *array[4], *s;
561         const struct dentry *p;
562         int depth;
563         int i, n;
564 
565         switch (fmt[1]) {
566                 case '2': case '3': case '4':
567                         depth = fmt[1] - '';
568                         break;
569                 default:
570                         depth = 1;
571         }
572 
573         rcu_read_lock();
574         for (i = 0; i < depth; i++, d = p) {
575                 p = ACCESS_ONCE(d->d_parent);
576                 array[i] = ACCESS_ONCE(d->d_name.name);
577                 if (p == d) {
578                         if (i)
579                                 array[i] = "";
580                         i++;
581                         break;
582                 }
583         }
584         s = array[--i];
585         for (n = 0; n != spec.precision; n++, buf++) {
586                 char c = *s++;
587                 if (!c) {
588                         if (!i)
589                                 break;
590                         c = '/';
591                         s = array[--i];
592                 }
593                 if (buf < end)
594                         *buf = c;
595         }
596         rcu_read_unlock();
597         if (n < spec.field_width) {
598                 /* we want to pad the sucker */
599                 unsigned spaces = spec.field_width - n;
600                 if (!(spec.flags & LEFT)) {
601                         widen(buf - n, end, n, spaces);
602                         return buf + spaces;
603                 }
604                 while (spaces--) {
605                         if (buf < end)
606                                 *buf = ' ';
607                         ++buf;
608                 }
609         }
610         return buf;
611 }
612 
613 static noinline_for_stack
614 char *symbol_string(char *buf, char *end, void *ptr,
615                     struct printf_spec spec, const char *fmt)
616 {
617         unsigned long value;
618 #ifdef CONFIG_KALLSYMS
619         char sym[KSYM_SYMBOL_LEN];
620 #endif
621 
622         if (fmt[1] == 'R')
623                 ptr = __builtin_extract_return_addr(ptr);
624         value = (unsigned long)ptr;
625 
626 #ifdef CONFIG_KALLSYMS
627         if (*fmt == 'B')
628                 sprint_backtrace(sym, value);
629         else if (*fmt != 'f' && *fmt != 's')
630                 sprint_symbol(sym, value);
631         else
632                 sprint_symbol_no_offset(sym, value);
633 
634         return string(buf, end, sym, spec);
635 #else
636         spec.field_width = 2 * sizeof(void *);
637         spec.flags |= SPECIAL | SMALL | ZEROPAD;
638         spec.base = 16;
639 
640         return number(buf, end, value, spec);
641 #endif
642 }
643 
644 static noinline_for_stack
645 char *resource_string(char *buf, char *end, struct resource *res,
646                       struct printf_spec spec, const char *fmt)
647 {
648 #ifndef IO_RSRC_PRINTK_SIZE
649 #define IO_RSRC_PRINTK_SIZE     6
650 #endif
651 
652 #ifndef MEM_RSRC_PRINTK_SIZE
653 #define MEM_RSRC_PRINTK_SIZE    10
654 #endif
655         static const struct printf_spec io_spec = {
656                 .base = 16,
657                 .field_width = IO_RSRC_PRINTK_SIZE,
658                 .precision = -1,
659                 .flags = SPECIAL | SMALL | ZEROPAD,
660         };
661         static const struct printf_spec mem_spec = {
662                 .base = 16,
663                 .field_width = MEM_RSRC_PRINTK_SIZE,
664                 .precision = -1,
665                 .flags = SPECIAL | SMALL | ZEROPAD,
666         };
667         static const struct printf_spec bus_spec = {
668                 .base = 16,
669                 .field_width = 2,
670                 .precision = -1,
671                 .flags = SMALL | ZEROPAD,
672         };
673         static const struct printf_spec dec_spec = {
674                 .base = 10,
675                 .precision = -1,
676                 .flags = 0,
677         };
678         static const struct printf_spec str_spec = {
679                 .field_width = -1,
680                 .precision = 10,
681                 .flags = LEFT,
682         };
683         static const struct printf_spec flag_spec = {
684                 .base = 16,
685                 .precision = -1,
686                 .flags = SPECIAL | SMALL,
687         };
688 
689         /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
690          * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
691 #define RSRC_BUF_SIZE           ((2 * sizeof(resource_size_t)) + 4)
692 #define FLAG_BUF_SIZE           (2 * sizeof(res->flags))
693 #define DECODED_BUF_SIZE        sizeof("[mem - 64bit pref window disabled]")
694 #define RAW_BUF_SIZE            sizeof("[mem - flags 0x]")
695         char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
696                      2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
697 
698         char *p = sym, *pend = sym + sizeof(sym);
699         int decode = (fmt[0] == 'R') ? 1 : 0;
700         const struct printf_spec *specp;
701 
702         *p++ = '[';
703         if (res->flags & IORESOURCE_IO) {
704                 p = string(p, pend, "io  ", str_spec);
705                 specp = &io_spec;
706         } else if (res->flags & IORESOURCE_MEM) {
707                 p = string(p, pend, "mem ", str_spec);
708                 specp = &mem_spec;
709         } else if (res->flags & IORESOURCE_IRQ) {
710                 p = string(p, pend, "irq ", str_spec);
711                 specp = &dec_spec;
712         } else if (res->flags & IORESOURCE_DMA) {
713                 p = string(p, pend, "dma ", str_spec);
714                 specp = &dec_spec;
715         } else if (res->flags & IORESOURCE_BUS) {
716                 p = string(p, pend, "bus ", str_spec);
717                 specp = &bus_spec;
718         } else {
719                 p = string(p, pend, "??? ", str_spec);
720                 specp = &mem_spec;
721                 decode = 0;
722         }
723         if (decode && res->flags & IORESOURCE_UNSET) {
724                 p = string(p, pend, "size ", str_spec);
725                 p = number(p, pend, resource_size(res), *specp);
726         } else {
727                 p = number(p, pend, res->start, *specp);
728                 if (res->start != res->end) {
729                         *p++ = '-';
730                         p = number(p, pend, res->end, *specp);
731                 }
732         }
733         if (decode) {
734                 if (res->flags & IORESOURCE_MEM_64)
735                         p = string(p, pend, " 64bit", str_spec);
736                 if (res->flags & IORESOURCE_PREFETCH)
737                         p = string(p, pend, " pref", str_spec);
738                 if (res->flags & IORESOURCE_WINDOW)
739                         p = string(p, pend, " window", str_spec);
740                 if (res->flags & IORESOURCE_DISABLED)
741                         p = string(p, pend, " disabled", str_spec);
742         } else {
743                 p = string(p, pend, " flags ", str_spec);
744                 p = number(p, pend, res->flags, flag_spec);
745         }
746         *p++ = ']';
747         *p = '\0';
748 
749         return string(buf, end, sym, spec);
750 }
751 
752 static noinline_for_stack
753 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
754                  const char *fmt)
755 {
756         int i, len = 1;         /* if we pass '%ph[CDN]', field width remains
757                                    negative value, fallback to the default */
758         char separator;
759 
760         if (spec.field_width == 0)
761                 /* nothing to print */
762                 return buf;
763 
764         if (ZERO_OR_NULL_PTR(addr))
765                 /* NULL pointer */
766                 return string(buf, end, NULL, spec);
767 
768         switch (fmt[1]) {
769         case 'C':
770                 separator = ':';
771                 break;
772         case 'D':
773                 separator = '-';
774                 break;
775         case 'N':
776                 separator = 0;
777                 break;
778         default:
779                 separator = ' ';
780                 break;
781         }
782 
783         if (spec.field_width > 0)
784                 len = min_t(int, spec.field_width, 64);
785 
786         for (i = 0; i < len && buf < end - 1; i++) {
787                 buf = hex_byte_pack(buf, addr[i]);
788 
789                 if (buf < end && separator && i != len - 1)
790                         *buf++ = separator;
791         }
792 
793         return buf;
794 }
795 
796 static noinline_for_stack
797 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
798                     struct printf_spec spec, const char *fmt)
799 {
800         const int CHUNKSZ = 32;
801         int nr_bits = max_t(int, spec.field_width, 0);
802         int i, chunksz;
803         bool first = true;
804 
805         /* reused to print numbers */
806         spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
807 
808         chunksz = nr_bits & (CHUNKSZ - 1);
809         if (chunksz == 0)
810                 chunksz = CHUNKSZ;
811 
812         i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
813         for (; i >= 0; i -= CHUNKSZ) {
814                 u32 chunkmask, val;
815                 int word, bit;
816 
817                 chunkmask = ((1ULL << chunksz) - 1);
818                 word = i / BITS_PER_LONG;
819                 bit = i % BITS_PER_LONG;
820                 val = (bitmap[word] >> bit) & chunkmask;
821 
822                 if (!first) {
823                         if (buf < end)
824                                 *buf = ',';
825                         buf++;
826                 }
827                 first = false;
828 
829                 spec.field_width = DIV_ROUND_UP(chunksz, 4);
830                 buf = number(buf, end, val, spec);
831 
832                 chunksz = CHUNKSZ;
833         }
834         return buf;
835 }
836 
837 static noinline_for_stack
838 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
839                          struct printf_spec spec, const char *fmt)
840 {
841         int nr_bits = max_t(int, spec.field_width, 0);
842         /* current bit is 'cur', most recently seen range is [rbot, rtop] */
843         int cur, rbot, rtop;
844         bool first = true;
845 
846         /* reused to print numbers */
847         spec = (struct printf_spec){ .base = 10 };
848 
849         rbot = cur = find_first_bit(bitmap, nr_bits);
850         while (cur < nr_bits) {
851                 rtop = cur;
852                 cur = find_next_bit(bitmap, nr_bits, cur + 1);
853                 if (cur < nr_bits && cur <= rtop + 1)
854                         continue;
855 
856                 if (!first) {
857                         if (buf < end)
858                                 *buf = ',';
859                         buf++;
860                 }
861                 first = false;
862 
863                 buf = number(buf, end, rbot, spec);
864                 if (rbot < rtop) {
865                         if (buf < end)
866                                 *buf = '-';
867                         buf++;
868 
869                         buf = number(buf, end, rtop, spec);
870                 }
871 
872                 rbot = cur;
873         }
874         return buf;
875 }
876 
877 static noinline_for_stack
878 char *mac_address_string(char *buf, char *end, u8 *addr,
879                          struct printf_spec spec, const char *fmt)
880 {
881         char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
882         char *p = mac_addr;
883         int i;
884         char separator;
885         bool reversed = false;
886 
887         switch (fmt[1]) {
888         case 'F':
889                 separator = '-';
890                 break;
891 
892         case 'R':
893                 reversed = true;
894                 /* fall through */
895 
896         default:
897                 separator = ':';
898                 break;
899         }
900 
901         for (i = 0; i < 6; i++) {
902                 if (reversed)
903                         p = hex_byte_pack(p, addr[5 - i]);
904                 else
905                         p = hex_byte_pack(p, addr[i]);
906 
907                 if (fmt[0] == 'M' && i != 5)
908                         *p++ = separator;
909         }
910         *p = '\0';
911 
912         return string(buf, end, mac_addr, spec);
913 }
914 
915 static noinline_for_stack
916 char *ip4_string(char *p, const u8 *addr, const char *fmt)
917 {
918         int i;
919         bool leading_zeros = (fmt[0] == 'i');
920         int index;
921         int step;
922 
923         switch (fmt[2]) {
924         case 'h':
925 #ifdef __BIG_ENDIAN
926                 index = 0;
927                 step = 1;
928 #else
929                 index = 3;
930                 step = -1;
931 #endif
932                 break;
933         case 'l':
934                 index = 3;
935                 step = -1;
936                 break;
937         case 'n':
938         case 'b':
939         default:
940                 index = 0;
941                 step = 1;
942                 break;
943         }
944         for (i = 0; i < 4; i++) {
945                 char temp[3];   /* hold each IP quad in reverse order */
946                 int digits = put_dec_trunc8(temp, addr[index]) - temp;
947                 if (leading_zeros) {
948                         if (digits < 3)
949                                 *p++ = '';
950                         if (digits < 2)
951                                 *p++ = '';
952                 }
953                 /* reverse the digits in the quad */
954                 while (digits--)
955                         *p++ = temp[digits];
956                 if (i < 3)
957                         *p++ = '.';
958                 index += step;
959         }
960         *p = '\0';
961 
962         return p;
963 }
964 
965 static noinline_for_stack
966 char *ip6_compressed_string(char *p, const char *addr)
967 {
968         int i, j, range;
969         unsigned char zerolength[8];
970         int longest = 1;
971         int colonpos = -1;
972         u16 word;
973         u8 hi, lo;
974         bool needcolon = false;
975         bool useIPv4;
976         struct in6_addr in6;
977 
978         memcpy(&in6, addr, sizeof(struct in6_addr));
979 
980         useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
981 
982         memset(zerolength, 0, sizeof(zerolength));
983 
984         if (useIPv4)
985                 range = 6;
986         else
987                 range = 8;
988 
989         /* find position of longest 0 run */
990         for (i = 0; i < range; i++) {
991                 for (j = i; j < range; j++) {
992                         if (in6.s6_addr16[j] != 0)
993                                 break;
994                         zerolength[i]++;
995                 }
996         }
997         for (i = 0; i < range; i++) {
998                 if (zerolength[i] > longest) {
999                         longest = zerolength[i];
1000                         colonpos = i;
1001                 }
1002         }
1003         if (longest == 1)               /* don't compress a single 0 */
1004                 colonpos = -1;
1005 
1006         /* emit address */
1007         for (i = 0; i < range; i++) {
1008                 if (i == colonpos) {
1009                         if (needcolon || i == 0)
1010                                 *p++ = ':';
1011                         *p++ = ':';
1012                         needcolon = false;
1013                         i += longest - 1;
1014                         continue;
1015                 }
1016                 if (needcolon) {
1017                         *p++ = ':';
1018                         needcolon = false;
1019                 }
1020                 /* hex u16 without leading 0s */
1021                 word = ntohs(in6.s6_addr16[i]);
1022                 hi = word >> 8;
1023                 lo = word & 0xff;
1024                 if (hi) {
1025                         if (hi > 0x0f)
1026                                 p = hex_byte_pack(p, hi);
1027                         else
1028                                 *p++ = hex_asc_lo(hi);
1029                         p = hex_byte_pack(p, lo);
1030                 }
1031                 else if (lo > 0x0f)
1032                         p = hex_byte_pack(p, lo);
1033                 else
1034                         *p++ = hex_asc_lo(lo);
1035                 needcolon = true;
1036         }
1037 
1038         if (useIPv4) {
1039                 if (needcolon)
1040                         *p++ = ':';
1041                 p = ip4_string(p, &in6.s6_addr[12], "I4");
1042         }
1043         *p = '\0';
1044 
1045         return p;
1046 }
1047 
1048 static noinline_for_stack
1049 char *ip6_string(char *p, const char *addr, const char *fmt)
1050 {
1051         int i;
1052 
1053         for (i = 0; i < 8; i++) {
1054                 p = hex_byte_pack(p, *addr++);
1055                 p = hex_byte_pack(p, *addr++);
1056                 if (fmt[0] == 'I' && i != 7)
1057                         *p++ = ':';
1058         }
1059         *p = '\0';
1060 
1061         return p;
1062 }
1063 
1064 static noinline_for_stack
1065 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1066                       struct printf_spec spec, const char *fmt)
1067 {
1068         char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1069 
1070         if (fmt[0] == 'I' && fmt[2] == 'c')
1071                 ip6_compressed_string(ip6_addr, addr);
1072         else
1073                 ip6_string(ip6_addr, addr, fmt);
1074 
1075         return string(buf, end, ip6_addr, spec);
1076 }
1077 
1078 static noinline_for_stack
1079 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1080                       struct printf_spec spec, const char *fmt)
1081 {
1082         char ip4_addr[sizeof("255.255.255.255")];
1083 
1084         ip4_string(ip4_addr, addr, fmt);
1085 
1086         return string(buf, end, ip4_addr, spec);
1087 }
1088 
1089 static noinline_for_stack
1090 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1091                          struct printf_spec spec, const char *fmt)
1092 {
1093         bool have_p = false, have_s = false, have_f = false, have_c = false;
1094         char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1095                       sizeof(":12345") + sizeof("/123456789") +
1096                       sizeof("%1234567890")];
1097         char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1098         const u8 *addr = (const u8 *) &sa->sin6_addr;
1099         char fmt6[2] = { fmt[0], '6' };
1100         u8 off = 0;
1101 
1102         fmt++;
1103         while (isalpha(*++fmt)) {
1104                 switch (*fmt) {
1105                 case 'p':
1106                         have_p = true;
1107                         break;
1108                 case 'f':
1109                         have_f = true;
1110                         break;
1111                 case 's':
1112                         have_s = true;
1113                         break;
1114                 case 'c':
1115                         have_c = true;
1116                         break;
1117                 }
1118         }
1119 
1120         if (have_p || have_s || have_f) {
1121                 *p = '[';
1122                 off = 1;
1123         }
1124 
1125         if (fmt6[0] == 'I' && have_c)
1126                 p = ip6_compressed_string(ip6_addr + off, addr);
1127         else
1128                 p = ip6_string(ip6_addr + off, addr, fmt6);
1129 
1130         if (have_p || have_s || have_f)
1131                 *p++ = ']';
1132 
1133         if (have_p) {
1134                 *p++ = ':';
1135                 p = number(p, pend, ntohs(sa->sin6_port), spec);
1136         }
1137         if (have_f) {
1138                 *p++ = '/';
1139                 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1140                                           IPV6_FLOWINFO_MASK), spec);
1141         }
1142         if (have_s) {
1143                 *p++ = '%';
1144                 p = number(p, pend, sa->sin6_scope_id, spec);
1145         }
1146         *p = '\0';
1147 
1148         return string(buf, end, ip6_addr, spec);
1149 }
1150 
1151 static noinline_for_stack
1152 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1153                          struct printf_spec spec, const char *fmt)
1154 {
1155         bool have_p = false;
1156         char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1157         char *pend = ip4_addr + sizeof(ip4_addr);
1158         const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1159         char fmt4[3] = { fmt[0], '4', 0 };
1160 
1161         fmt++;
1162         while (isalpha(*++fmt)) {
1163                 switch (*fmt) {
1164                 case 'p':
1165                         have_p = true;
1166                         break;
1167                 case 'h':
1168                 case 'l':
1169                 case 'n':
1170                 case 'b':
1171                         fmt4[2] = *fmt;
1172                         break;
1173                 }
1174         }
1175 
1176         p = ip4_string(ip4_addr, addr, fmt4);
1177         if (have_p) {
1178                 *p++ = ':';
1179                 p = number(p, pend, ntohs(sa->sin_port), spec);
1180         }
1181         *p = '\0';
1182 
1183         return string(buf, end, ip4_addr, spec);
1184 }
1185 
1186 static noinline_for_stack
1187 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1188                      const char *fmt)
1189 {
1190         bool found = true;
1191         int count = 1;
1192         unsigned int flags = 0;
1193         int len;
1194 
1195         if (spec.field_width == 0)
1196                 return buf;                             /* nothing to print */
1197 
1198         if (ZERO_OR_NULL_PTR(addr))
1199                 return string(buf, end, NULL, spec);    /* NULL pointer */
1200 
1201 
1202         do {
1203                 switch (fmt[count++]) {
1204                 case 'a':
1205                         flags |= ESCAPE_ANY;
1206                         break;
1207                 case 'c':
1208                         flags |= ESCAPE_SPECIAL;
1209                         break;
1210                 case 'h':
1211                         flags |= ESCAPE_HEX;
1212                         break;
1213                 case 'n':
1214                         flags |= ESCAPE_NULL;
1215                         break;
1216                 case 'o':
1217                         flags |= ESCAPE_OCTAL;
1218                         break;
1219                 case 'p':
1220                         flags |= ESCAPE_NP;
1221                         break;
1222                 case 's':
1223                         flags |= ESCAPE_SPACE;
1224                         break;
1225                 default:
1226                         found = false;
1227                         break;
1228                 }
1229         } while (found);
1230 
1231         if (!flags)
1232                 flags = ESCAPE_ANY_NP;
1233 
1234         len = spec.field_width < 0 ? 1 : spec.field_width;
1235 
1236         /* Ignore the error. We print as many characters as we can */
1237         string_escape_mem(addr, len, &buf, end - buf, flags, NULL);
1238 
1239         return buf;
1240 }
1241 
1242 static noinline_for_stack
1243 char *uuid_string(char *buf, char *end, const u8 *addr,
1244                   struct printf_spec spec, const char *fmt)
1245 {
1246         char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
1247         char *p = uuid;
1248         int i;
1249         static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
1250         static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
1251         const u8 *index = be;
1252         bool uc = false;
1253 
1254         switch (*(++fmt)) {
1255         case 'L':
1256                 uc = true;              /* fall-through */
1257         case 'l':
1258                 index = le;
1259                 break;
1260         case 'B':
1261                 uc = true;
1262                 break;
1263         }
1264 
1265         for (i = 0; i < 16; i++) {
1266                 p = hex_byte_pack(p, addr[index[i]]);
1267                 switch (i) {
1268                 case 3:
1269                 case 5:
1270                 case 7:
1271                 case 9:
1272                         *p++ = '-';
1273                         break;
1274                 }
1275         }
1276 
1277         *p = 0;
1278 
1279         if (uc) {
1280                 p = uuid;
1281                 do {
1282                         *p = toupper(*p);
1283                 } while (*(++p));
1284         }
1285 
1286         return string(buf, end, uuid, spec);
1287 }
1288 
1289 static
1290 char *netdev_feature_string(char *buf, char *end, const u8 *addr,
1291                       struct printf_spec spec)
1292 {
1293         spec.flags |= SPECIAL | SMALL | ZEROPAD;
1294         if (spec.field_width == -1)
1295                 spec.field_width = 2 + 2 * sizeof(netdev_features_t);
1296         spec.base = 16;
1297 
1298         return number(buf, end, *(const netdev_features_t *)addr, spec);
1299 }
1300 
1301 static noinline_for_stack
1302 char *address_val(char *buf, char *end, const void *addr,
1303                   struct printf_spec spec, const char *fmt)
1304 {
1305         unsigned long long num;
1306 
1307         spec.flags |= SPECIAL | SMALL | ZEROPAD;
1308         spec.base = 16;
1309 
1310         switch (fmt[1]) {
1311         case 'd':
1312                 num = *(const dma_addr_t *)addr;
1313                 spec.field_width = sizeof(dma_addr_t) * 2 + 2;
1314                 break;
1315         case 'p':
1316         default:
1317                 num = *(const phys_addr_t *)addr;
1318                 spec.field_width = sizeof(phys_addr_t) * 2 + 2;
1319                 break;
1320         }
1321 
1322         return number(buf, end, num, spec);
1323 }
1324 
1325 int kptr_restrict __read_mostly;
1326 
1327 /*
1328  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1329  * by an extra set of alphanumeric characters that are extended format
1330  * specifiers.
1331  *
1332  * Right now we handle:
1333  *
1334  * - 'F' For symbolic function descriptor pointers with offset
1335  * - 'f' For simple symbolic function names without offset
1336  * - 'S' For symbolic direct pointers with offset
1337  * - 's' For symbolic direct pointers without offset
1338  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1339  * - 'B' For backtraced symbolic direct pointers with offset
1340  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1341  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1342  * - 'b[l]' For a bitmap, the number of bits is determined by the field
1343  *       width which must be explicitly specified either as part of the
1344  *       format string '%32b[l]' or through '%*b[l]', [l] selects
1345  *       range-list format instead of hex format
1346  * - 'M' For a 6-byte MAC address, it prints the address in the
1347  *       usual colon-separated hex notation
1348  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1349  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1350  *       with a dash-separated hex notation
1351  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1352  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1353  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1354  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1355  *       [S][pfs]
1356  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1357  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1358  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1359  *       IPv6 omits the colons (01020304...0f)
1360  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1361  *       [S][pfs]
1362  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1363  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1364  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1365  * - 'I[6S]c' for IPv6 addresses printed as specified by
1366  *       http://tools.ietf.org/html/rfc5952
1367  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1368  *                of the following flags (see string_escape_mem() for the
1369  *                details):
1370  *                  a - ESCAPE_ANY
1371  *                  c - ESCAPE_SPECIAL
1372  *                  h - ESCAPE_HEX
1373  *                  n - ESCAPE_NULL
1374  *                  o - ESCAPE_OCTAL
1375  *                  p - ESCAPE_NP
1376  *                  s - ESCAPE_SPACE
1377  *                By default ESCAPE_ANY_NP is used.
1378  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1379  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1380  *       Options for %pU are:
1381  *         b big endian lower case hex (default)
1382  *         B big endian UPPER case hex
1383  *         l little endian lower case hex
1384  *         L little endian UPPER case hex
1385  *           big endian output byte order is:
1386  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1387  *           little endian output byte order is:
1388  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1389  * - 'V' For a struct va_format which contains a format string * and va_list *,
1390  *       call vsnprintf(->format, *->va_list).
1391  *       Implements a "recursive vsnprintf".
1392  *       Do not use this feature without some mechanism to verify the
1393  *       correctness of the format string and va_list arguments.
1394  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1395  * - 'NF' For a netdev_features_t
1396  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1397  *            a certain separator (' ' by default):
1398  *              C colon
1399  *              D dash
1400  *              N no separator
1401  *            The maximum supported length is 64 bytes of the input. Consider
1402  *            to use print_hex_dump() for the larger input.
1403  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1404  *           (default assumed to be phys_addr_t, passed by reference)
1405  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1406  * - 'D[234]' Same as 'd' but for a struct file
1407  *
1408  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1409  * function pointers are really function descriptors, which contain a
1410  * pointer to the real address.
1411  */
1412 static noinline_for_stack
1413 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1414               struct printf_spec spec)
1415 {
1416         int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);
1417 
1418         if (!ptr && *fmt != 'K') {
1419                 /*
1420                  * Print (null) with the same width as a pointer so it makes
1421                  * tabular output look nice.
1422                  */
1423                 if (spec.field_width == -1)
1424                         spec.field_width = default_width;
1425                 return string(buf, end, "(null)", spec);
1426         }
1427 
1428         switch (*fmt) {
1429         case 'F':
1430         case 'f':
1431                 ptr = dereference_function_descriptor(ptr);
1432                 /* Fallthrough */
1433         case 'S':
1434         case 's':
1435         case 'B':
1436                 return symbol_string(buf, end, ptr, spec, fmt);
1437         case 'R':
1438         case 'r':
1439                 return resource_string(buf, end, ptr, spec, fmt);
1440         case 'h':
1441                 return hex_string(buf, end, ptr, spec, fmt);
1442         case 'b':
1443                 switch (fmt[1]) {
1444                 case 'l':
1445                         return bitmap_list_string(buf, end, ptr, spec, fmt);
1446                 default:
1447                         return bitmap_string(buf, end, ptr, spec, fmt);
1448                 }
1449         case 'M':                       /* Colon separated: 00:01:02:03:04:05 */
1450         case 'm':                       /* Contiguous: 000102030405 */
1451                                         /* [mM]F (FDDI) */
1452                                         /* [mM]R (Reverse order; Bluetooth) */
1453                 return mac_address_string(buf, end, ptr, spec, fmt);
1454         case 'I':                       /* Formatted IP supported
1455                                          * 4:   1.2.3.4
1456                                          * 6:   0001:0203:...:0708
1457                                          * 6c:  1::708 or 1::1.2.3.4
1458                                          */
1459         case 'i':                       /* Contiguous:
1460                                          * 4:   001.002.003.004
1461                                          * 6:   000102...0f
1462                                          */
1463                 switch (fmt[1]) {
1464                 case '6':
1465                         return ip6_addr_string(buf, end, ptr, spec, fmt);
1466                 case '4':
1467                         return ip4_addr_string(buf, end, ptr, spec, fmt);
1468                 case 'S': {
1469                         const union {
1470                                 struct sockaddr         raw;
1471                                 struct sockaddr_in      v4;
1472                                 struct sockaddr_in6     v6;
1473                         } *sa = ptr;
1474 
1475                         switch (sa->raw.sa_family) {
1476                         case AF_INET:
1477                                 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1478                         case AF_INET6:
1479                                 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1480                         default:
1481                                 return string(buf, end, "(invalid address)", spec);
1482                         }}
1483                 }
1484                 break;
1485         case 'E':
1486                 return escaped_string(buf, end, ptr, spec, fmt);
1487         case 'U':
1488                 return uuid_string(buf, end, ptr, spec, fmt);
1489         case 'V':
1490                 {
1491                         va_list va;
1492 
1493                         va_copy(va, *((struct va_format *)ptr)->va);
1494                         buf += vsnprintf(buf, end > buf ? end - buf : 0,
1495                                          ((struct va_format *)ptr)->fmt, va);
1496                         va_end(va);
1497                         return buf;
1498                 }
1499         case 'K':
1500                 /*
1501                  * %pK cannot be used in IRQ context because its test
1502                  * for CAP_SYSLOG would be meaningless.
1503                  */
1504                 if (kptr_restrict && (in_irq() || in_serving_softirq() ||
1505                                       in_nmi())) {
1506                         if (spec.field_width == -1)
1507                                 spec.field_width = default_width;
1508                         return string(buf, end, "pK-error", spec);
1509                 }
1510 
1511                 switch (kptr_restrict) {
1512                 case 0:
1513                         /* Always print %pK values */
1514                         break;
1515                 case 1: {
1516                         /*
1517                          * Only print the real pointer value if the current
1518                          * process has CAP_SYSLOG and is running with the
1519                          * same credentials it started with. This is because
1520                          * access to files is checked at open() time, but %pK
1521                          * checks permission at read() time. We don't want to
1522                          * leak pointer values if a binary opens a file using
1523                          * %pK and then elevates privileges before reading it.
1524                          */
1525                         const struct cred *cred = current_cred();
1526 
1527                         if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1528                             !uid_eq(cred->euid, cred->uid) ||
1529                             !gid_eq(cred->egid, cred->gid))
1530                                 ptr = NULL;
1531                         break;
1532                 }
1533                 case 2:
1534                 default:
1535                         /* Always print 0's for %pK */
1536                         ptr = NULL;
1537                         break;
1538                 }
1539                 break;
1540 
1541         case 'N':
1542                 switch (fmt[1]) {
1543                 case 'F':
1544                         return netdev_feature_string(buf, end, ptr, spec);
1545                 }
1546                 break;
1547         case 'a':
1548                 return address_val(buf, end, ptr, spec, fmt);
1549         case 'd':
1550                 return dentry_name(buf, end, ptr, spec, fmt);
1551         case 'D':
1552                 return dentry_name(buf, end,
1553                                    ((const struct file *)ptr)->f_path.dentry,
1554                                    spec, fmt);
1555         }
1556         spec.flags |= SMALL;
1557         if (spec.field_width == -1) {
1558                 spec.field_width = default_width;
1559                 spec.flags |= ZEROPAD;
1560         }
1561         spec.base = 16;
1562 
1563         return number(buf, end, (unsigned long) ptr, spec);
1564 }
1565 
1566 /*
1567  * Helper function to decode printf style format.
1568  * Each call decode a token from the format and return the
1569  * number of characters read (or likely the delta where it wants
1570  * to go on the next call).
1571  * The decoded token is returned through the parameters
1572  *
1573  * 'h', 'l', or 'L' for integer fields
1574  * 'z' support added 23/7/1999 S.H.
1575  * 'z' changed to 'Z' --davidm 1/25/99
1576  * 't' added for ptrdiff_t
1577  *
1578  * @fmt: the format string
1579  * @type of the token returned
1580  * @flags: various flags such as +, -, # tokens..
1581  * @field_width: overwritten width
1582  * @base: base of the number (octal, hex, ...)
1583  * @precision: precision of a number
1584  * @qualifier: qualifier of a number (long, size_t, ...)
1585  */
1586 static noinline_for_stack
1587 int format_decode(const char *fmt, struct printf_spec *spec)
1588 {
1589         const char *start = fmt;
1590 
1591         /* we finished early by reading the field width */
1592         if (spec->type == FORMAT_TYPE_WIDTH) {
1593                 if (spec->field_width < 0) {
1594                         spec->field_width = -spec->field_width;
1595                         spec->flags |= LEFT;
1596                 }
1597                 spec->type = FORMAT_TYPE_NONE;
1598                 goto precision;
1599         }
1600 
1601         /* we finished early by reading the precision */
1602         if (spec->type == FORMAT_TYPE_PRECISION) {
1603                 if (spec->precision < 0)
1604                         spec->precision = 0;
1605 
1606                 spec->type = FORMAT_TYPE_NONE;
1607                 goto qualifier;
1608         }
1609 
1610         /* By default */
1611         spec->type = FORMAT_TYPE_NONE;
1612 
1613         for (; *fmt ; ++fmt) {
1614                 if (*fmt == '%')
1615                         break;
1616         }
1617 
1618         /* Return the current non-format string */
1619         if (fmt != start || !*fmt)
1620                 return fmt - start;
1621 
1622         /* Process flags */
1623         spec->flags = 0;
1624 
1625         while (1) { /* this also skips first '%' */
1626                 bool found = true;
1627 
1628                 ++fmt;
1629 
1630                 switch (*fmt) {
1631                 case '-': spec->flags |= LEFT;    break;
1632                 case '+': spec->flags |= PLUS;    break;
1633                 case ' ': spec->flags |= SPACE;   break;
1634                 case '#': spec->flags |= SPECIAL; break;
1635                 case '': spec->flags |= ZEROPAD; break;
1636                 default:  found = false;
1637                 }
1638 
1639                 if (!found)
1640                         break;
1641         }
1642 
1643         /* get field width */
1644         spec->field_width = -1;
1645 
1646         if (isdigit(*fmt))
1647                 spec->field_width = skip_atoi(&fmt);
1648         else if (*fmt == '*') {
1649                 /* it's the next argument */
1650                 spec->type = FORMAT_TYPE_WIDTH;
1651                 return ++fmt - start;
1652         }
1653 
1654 precision:
1655         /* get the precision */
1656         spec->precision = -1;
1657         if (*fmt == '.') {
1658                 ++fmt;
1659                 if (isdigit(*fmt)) {
1660                         spec->precision = skip_atoi(&fmt);
1661                         if (spec->precision < 0)
1662                                 spec->precision = 0;
1663                 } else if (*fmt == '*') {
1664                         /* it's the next argument */
1665                         spec->type = FORMAT_TYPE_PRECISION;
1666                         return ++fmt - start;
1667                 }
1668         }
1669 
1670 qualifier:
1671         /* get the conversion qualifier */
1672         spec->qualifier = -1;
1673         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1674             _tolower(*fmt) == 'z' || *fmt == 't') {
1675                 spec->qualifier = *fmt++;
1676                 if (unlikely(spec->qualifier == *fmt)) {
1677                         if (spec->qualifier == 'l') {
1678                                 spec->qualifier = 'L';
1679                                 ++fmt;
1680                         } else if (spec->qualifier == 'h') {
1681                                 spec->qualifier = 'H';
1682                                 ++fmt;
1683                         }
1684                 }
1685         }
1686 
1687         /* default base */
1688         spec->base = 10;
1689         switch (*fmt) {
1690         case 'c':
1691                 spec->type = FORMAT_TYPE_CHAR;
1692                 return ++fmt - start;
1693 
1694         case 's':
1695                 spec->type = FORMAT_TYPE_STR;
1696                 return ++fmt - start;
1697 
1698         case 'p':
1699                 spec->type = FORMAT_TYPE_PTR;
1700                 return ++fmt - start;
1701 
1702         case '%':
1703                 spec->type = FORMAT_TYPE_PERCENT_CHAR;
1704                 return ++fmt - start;
1705 
1706         /* integer number formats - set up the flags and "break" */
1707         case 'o':
1708                 spec->base = 8;
1709                 break;
1710 
1711         case 'x':
1712                 spec->flags |= SMALL;
1713 
1714         case 'X':
1715                 spec->base = 16;
1716                 break;
1717 
1718         case 'd':
1719         case 'i':
1720                 spec->flags |= SIGN;
1721         case 'u':
1722                 break;
1723 
1724         case 'n':
1725                 /*
1726                  * Since %n poses a greater security risk than utility, treat
1727                  * it as an invalid format specifier. Warn about its use so
1728                  * that new instances don't get added.
1729                  */
1730                 WARN_ONCE(1, "Please remove ignored %%n in '%s'\n", fmt);
1731                 /* Fall-through */
1732 
1733         default:
1734                 spec->type = FORMAT_TYPE_INVALID;
1735                 return fmt - start;
1736         }
1737 
1738         if (spec->qualifier == 'L')
1739                 spec->type = FORMAT_TYPE_LONG_LONG;
1740         else if (spec->qualifier == 'l') {
1741                 if (spec->flags & SIGN)
1742                         spec->type = FORMAT_TYPE_LONG;
1743                 else
1744                         spec->type = FORMAT_TYPE_ULONG;
1745         } else if (_tolower(spec->qualifier) == 'z') {
1746                 spec->type = FORMAT_TYPE_SIZE_T;
1747         } else if (spec->qualifier == 't') {
1748                 spec->type = FORMAT_TYPE_PTRDIFF;
1749         } else if (spec->qualifier == 'H') {
1750                 if (spec->flags & SIGN)
1751                         spec->type = FORMAT_TYPE_BYTE;
1752                 else
1753                         spec->type = FORMAT_TYPE_UBYTE;
1754         } else if (spec->qualifier == 'h') {
1755                 if (spec->flags & SIGN)
1756                         spec->type = FORMAT_TYPE_SHORT;
1757                 else
1758                         spec->type = FORMAT_TYPE_USHORT;
1759         } else {
1760                 if (spec->flags & SIGN)
1761                         spec->type = FORMAT_TYPE_INT;
1762                 else
1763                         spec->type = FORMAT_TYPE_UINT;
1764         }
1765 
1766         return ++fmt - start;
1767 }
1768 
1769 /**
1770  * vsnprintf - Format a string and place it in a buffer
1771  * @buf: The buffer to place the result into
1772  * @size: The size of the buffer, including the trailing null space
1773  * @fmt: The format string to use
1774  * @args: Arguments for the format string
1775  *
1776  * This function follows C99 vsnprintf, but has some extensions:
1777  * %pS output the name of a text symbol with offset
1778  * %ps output the name of a text symbol without offset
1779  * %pF output the name of a function pointer with its offset
1780  * %pf output the name of a function pointer without its offset
1781  * %pB output the name of a backtrace symbol with its offset
1782  * %pR output the address range in a struct resource with decoded flags
1783  * %pr output the address range in a struct resource with raw flags
1784  * %pb output the bitmap with field width as the number of bits
1785  * %pbl output the bitmap as range list with field width as the number of bits
1786  * %pM output a 6-byte MAC address with colons
1787  * %pMR output a 6-byte MAC address with colons in reversed order
1788  * %pMF output a 6-byte MAC address with dashes
1789  * %pm output a 6-byte MAC address without colons
1790  * %pmR output a 6-byte MAC address without colons in reversed order
1791  * %pI4 print an IPv4 address without leading zeros
1792  * %pi4 print an IPv4 address with leading zeros
1793  * %pI6 print an IPv6 address with colons
1794  * %pi6 print an IPv6 address without colons
1795  * %pI6c print an IPv6 address as specified by RFC 5952
1796  * %pIS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1797  * %piS depending on sa_family of 'struct sockaddr *' print IPv4/IPv6 address
1798  * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1799  *   case.
1800  * %*pE[achnops] print an escaped buffer
1801  * %*ph[CDN] a variable-length hex string with a separator (supports up to 64
1802  *           bytes of the input)
1803  * %n is ignored
1804  *
1805  * ** Please update Documentation/printk-formats.txt when making changes **
1806  *
1807  * The return value is the number of characters which would
1808  * be generated for the given input, excluding the trailing
1809  * '\0', as per ISO C99. If you want to have the exact
1810  * number of characters written into @buf as return value
1811  * (not including the trailing '\0'), use vscnprintf(). If the
1812  * return is greater than or equal to @size, the resulting
1813  * string is truncated.
1814  *
1815  * If you're not already dealing with a va_list consider using snprintf().
1816  */
1817 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1818 {
1819         unsigned long long num;
1820         char *str, *end;
1821         struct printf_spec spec = {0};
1822 
1823         /* Reject out-of-range values early.  Large positive sizes are
1824            used for unknown buffer sizes. */
1825         if (WARN_ON_ONCE(size > INT_MAX))
1826                 return 0;
1827 
1828         str = buf;
1829         end = buf + size;
1830 
1831         /* Make sure end is always >= buf */
1832         if (end < buf) {
1833                 end = ((void *)-1);
1834                 size = end - buf;
1835         }
1836 
1837         while (*fmt) {
1838                 const char *old_fmt = fmt;
1839                 int read = format_decode(fmt, &spec);
1840 
1841                 fmt += read;
1842 
1843                 switch (spec.type) {
1844                 case FORMAT_TYPE_NONE: {
1845                         int copy = read;
1846                         if (str < end) {
1847                                 if (copy > end - str)
1848                                         copy = end - str;
1849                                 memcpy(str, old_fmt, copy);
1850                         }
1851                         str += read;
1852                         break;
1853                 }
1854 
1855                 case FORMAT_TYPE_WIDTH:
1856                         spec.field_width = va_arg(args, int);
1857                         break;
1858 
1859                 case FORMAT_TYPE_PRECISION:
1860                         spec.precision = va_arg(args, int);
1861                         break;
1862 
1863                 case FORMAT_TYPE_CHAR: {
1864                         char c;
1865 
1866                         if (!(spec.flags & LEFT)) {
1867                                 while (--spec.field_width > 0) {
1868                                         if (str < end)
1869                                                 *str = ' ';
1870                                         ++str;
1871 
1872                                 }
1873                         }
1874                         c = (unsigned char) va_arg(args, int);
1875                         if (str < end)
1876                                 *str = c;
1877                         ++str;
1878                         while (--spec.field_width > 0) {
1879                                 if (str < end)
1880                                         *str = ' ';
1881                                 ++str;
1882                         }
1883                         break;
1884                 }
1885 
1886                 case FORMAT_TYPE_STR:
1887                         str = string(str, end, va_arg(args, char *), spec);
1888                         break;
1889 
1890                 case FORMAT_TYPE_PTR:
1891                         str = pointer(fmt, str, end, va_arg(args, void *),
1892                                       spec);
1893                         while (isalnum(*fmt))
1894                                 fmt++;
1895                         break;
1896 
1897                 case FORMAT_TYPE_PERCENT_CHAR:
1898                         if (str < end)
1899                                 *str = '%';
1900                         ++str;
1901                         break;
1902 
1903                 case FORMAT_TYPE_INVALID:
1904                         if (str < end)
1905                                 *str = '%';
1906                         ++str;
1907                         break;
1908 
1909                 default:
1910                         switch (spec.type) {
1911                         case FORMAT_TYPE_LONG_LONG:
1912                                 num = va_arg(args, long long);
1913                                 break;
1914                         case FORMAT_TYPE_ULONG:
1915                                 num = va_arg(args, unsigned long);
1916                                 break;
1917                         case FORMAT_TYPE_LONG:
1918                                 num = va_arg(args, long);
1919                                 break;
1920                         case FORMAT_TYPE_SIZE_T:
1921                                 if (spec.flags & SIGN)
1922                                         num = va_arg(args, ssize_t);
1923                                 else
1924                                         num = va_arg(args, size_t);
1925                                 break;
1926                         case FORMAT_TYPE_PTRDIFF:
1927                                 num = va_arg(args, ptrdiff_t);
1928                                 break;
1929                         case FORMAT_TYPE_UBYTE:
1930                                 num = (unsigned char) va_arg(args, int);
1931                                 break;
1932                         case FORMAT_TYPE_BYTE:
1933                                 num = (signed char) va_arg(args, int);
1934                                 break;
1935                         case FORMAT_TYPE_USHORT:
1936                                 num = (unsigned short) va_arg(args, int);
1937                                 break;
1938                         case FORMAT_TYPE_SHORT:
1939                                 num = (short) va_arg(args, int);
1940                                 break;
1941                         case FORMAT_TYPE_INT:
1942                                 num = (int) va_arg(args, int);
1943                                 break;
1944                         default:
1945                                 num = va_arg(args, unsigned int);
1946                         }
1947 
1948                         str = number(str, end, num, spec);
1949                 }
1950         }
1951 
1952         if (size > 0) {
1953                 if (str < end)
1954                         *str = '\0';
1955                 else
1956                         end[-1] = '\0';
1957         }
1958 
1959         /* the trailing null byte doesn't count towards the total */
1960         return str-buf;
1961 
1962 }
1963 EXPORT_SYMBOL(vsnprintf);
1964 
1965 /**
1966  * vscnprintf - Format a string and place it in a buffer
1967  * @buf: The buffer to place the result into
1968  * @size: The size of the buffer, including the trailing null space
1969  * @fmt: The format string to use
1970  * @args: Arguments for the format string
1971  *
1972  * The return value is the number of characters which have been written into
1973  * the @buf not including the trailing '\0'. If @size is == 0 the function
1974  * returns 0.
1975  *
1976  * If you're not already dealing with a va_list consider using scnprintf().
1977  *
1978  * See the vsnprintf() documentation for format string extensions over C99.
1979  */
1980 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1981 {
1982         int i;
1983 
1984         i = vsnprintf(buf, size, fmt, args);
1985 
1986         if (likely(i < size))
1987                 return i;
1988         if (size != 0)
1989                 return size - 1;
1990         return 0;
1991 }
1992 EXPORT_SYMBOL(vscnprintf);
1993 
1994 /**
1995  * snprintf - Format a string and place it in a buffer
1996  * @buf: The buffer to place the result into
1997  * @size: The size of the buffer, including the trailing null space
1998  * @fmt: The format string to use
1999  * @...: Arguments for the format string
2000  *
2001  * The return value is the number of characters which would be
2002  * generated for the given input, excluding the trailing null,
2003  * as per ISO C99.  If the return is greater than or equal to
2004  * @size, the resulting string is truncated.
2005  *
2006  * See the vsnprintf() documentation for format string extensions over C99.
2007  */
2008 int snprintf(char *buf, size_t size, const char *fmt, ...)
2009 {
2010         va_list args;
2011         int i;
2012 
2013         va_start(args, fmt);
2014         i = vsnprintf(buf, size, fmt, args);
2015         va_end(args);
2016 
2017         return i;
2018 }
2019 EXPORT_SYMBOL(snprintf);
2020 
2021 /**
2022  * scnprintf - Format a string and place it in a buffer
2023  * @buf: The buffer to place the result into
2024  * @size: The size of the buffer, including the trailing null space
2025  * @fmt: The format string to use
2026  * @...: Arguments for the format string
2027  *
2028  * The return value is the number of characters written into @buf not including
2029  * the trailing '\0'. If @size is == 0 the function returns 0.
2030  */
2031 
2032 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2033 {
2034         va_list args;
2035         int i;
2036 
2037         va_start(args, fmt);
2038         i = vscnprintf(buf, size, fmt, args);
2039         va_end(args);
2040 
2041         return i;
2042 }
2043 EXPORT_SYMBOL(scnprintf);
2044 
2045 /**
2046  * vsprintf - Format a string and place it in a buffer
2047  * @buf: The buffer to place the result into
2048  * @fmt: The format string to use
2049  * @args: Arguments for the format string
2050  *
2051  * The function returns the number of characters written
2052  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2053  * buffer overflows.
2054  *
2055  * If you're not already dealing with a va_list consider using sprintf().
2056  *
2057  * See the vsnprintf() documentation for format string extensions over C99.
2058  */
2059 int vsprintf(char *buf, const char *fmt, va_list args)
2060 {
2061         return vsnprintf(buf, INT_MAX, fmt, args);
2062 }
2063 EXPORT_SYMBOL(vsprintf);
2064 
2065 /**
2066  * sprintf - Format a string and place it in a buffer
2067  * @buf: The buffer to place the result into
2068  * @fmt: The format string to use
2069  * @...: Arguments for the format string
2070  *
2071  * The function returns the number of characters written
2072  * into @buf. Use snprintf() or scnprintf() in order to avoid
2073  * buffer overflows.
2074  *
2075  * See the vsnprintf() documentation for format string extensions over C99.
2076  */
2077 int sprintf(char *buf, const char *fmt, ...)
2078 {
2079         va_list args;
2080         int i;
2081 
2082         va_start(args, fmt);
2083         i = vsnprintf(buf, INT_MAX, fmt, args);
2084         va_end(args);
2085 
2086         return i;
2087 }
2088 EXPORT_SYMBOL(sprintf);
2089 
2090 #ifdef CONFIG_BINARY_PRINTF
2091 /*
2092  * bprintf service:
2093  * vbin_printf() - VA arguments to binary data
2094  * bstr_printf() - Binary data to text string
2095  */
2096 
2097 /**
2098  * vbin_printf - Parse a format string and place args' binary value in a buffer
2099  * @bin_buf: The buffer to place args' binary value
2100  * @size: The size of the buffer(by words(32bits), not characters)
2101  * @fmt: The format string to use
2102  * @args: Arguments for the format string
2103  *
2104  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2105  * is skipped.
2106  *
2107  * The return value is the number of words(32bits) which would be generated for
2108  * the given input.
2109  *
2110  * NOTE:
2111  * If the return value is greater than @size, the resulting bin_buf is NOT
2112  * valid for bstr_printf().
2113  */
2114 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2115 {
2116         struct printf_spec spec = {0};
2117         char *str, *end;
2118 
2119         str = (char *)bin_buf;
2120         end = (char *)(bin_buf + size);
2121 
2122 #define save_arg(type)                                                  \
2123 do {                                                                    \
2124         if (sizeof(type) == 8) {                                        \
2125                 unsigned long long value;                               \
2126                 str = PTR_ALIGN(str, sizeof(u32));                      \
2127                 value = va_arg(args, unsigned long long);               \
2128                 if (str + sizeof(type) <= end) {                        \
2129                         *(u32 *)str = *(u32 *)&value;                   \
2130                         *(u32 *)(str + 4) = *((u32 *)&value + 1);       \
2131                 }                                                       \
2132         } else {                                                        \
2133                 unsigned long value;                                    \
2134                 str = PTR_ALIGN(str, sizeof(type));                     \
2135                 value = va_arg(args, int);                              \
2136                 if (str + sizeof(type) <= end)                          \
2137                         *(typeof(type) *)str = (type)value;             \
2138         }                                                               \
2139         str += sizeof(type);                                            \
2140 } while (0)
2141 
2142         while (*fmt) {
2143                 int read = format_decode(fmt, &spec);
2144 
2145                 fmt += read;
2146 
2147                 switch (spec.type) {
2148                 case FORMAT_TYPE_NONE:
2149                 case FORMAT_TYPE_INVALID:
2150                 case FORMAT_TYPE_PERCENT_CHAR:
2151                         break;
2152 
2153                 case FORMAT_TYPE_WIDTH:
2154                 case FORMAT_TYPE_PRECISION:
2155                         save_arg(int);
2156                         break;
2157 
2158                 case FORMAT_TYPE_CHAR:
2159                         save_arg(char);
2160                         break;
2161 
2162                 case FORMAT_TYPE_STR: {
2163                         const char *save_str = va_arg(args, char *);
2164                         size_t len;
2165 
2166                         if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2167                                         || (unsigned long)save_str < PAGE_SIZE)
2168                                 save_str = "(null)";
2169                         len = strlen(save_str) + 1;
2170                         if (str + len < end)
2171                                 memcpy(str, save_str, len);
2172                         str += len;
2173                         break;
2174                 }
2175 
2176                 case FORMAT_TYPE_PTR:
2177                         save_arg(void *);
2178                         /* skip all alphanumeric pointer suffixes */
2179                         while (isalnum(*fmt))
2180                                 fmt++;
2181                         break;
2182 
2183                 default:
2184                         switch (spec.type) {
2185 
2186                         case FORMAT_TYPE_LONG_LONG:
2187                                 save_arg(long long);
2188                                 break;
2189                         case FORMAT_TYPE_ULONG:
2190                         case FORMAT_TYPE_LONG:
2191                                 save_arg(unsigned long);
2192                                 break;
2193                         case FORMAT_TYPE_SIZE_T:
2194                                 save_arg(size_t);
2195                                 break;
2196                         case FORMAT_TYPE_PTRDIFF:
2197                                 save_arg(ptrdiff_t);
2198                                 break;
2199                         case FORMAT_TYPE_UBYTE:
2200                         case FORMAT_TYPE_BYTE:
2201                                 save_arg(char);
2202                                 break;
2203                         case FORMAT_TYPE_USHORT:
2204                         case FORMAT_TYPE_SHORT:
2205                                 save_arg(short);
2206                                 break;
2207                         default:
2208                                 save_arg(int);
2209                         }
2210                 }
2211         }
2212 
2213         return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2214 #undef save_arg
2215 }
2216 EXPORT_SYMBOL_GPL(vbin_printf);
2217 
2218 /**
2219  * bstr_printf - Format a string from binary arguments and place it in a buffer
2220  * @buf: The buffer to place the result into
2221  * @size: The size of the buffer, including the trailing null space
2222  * @fmt: The format string to use
2223  * @bin_buf: Binary arguments for the format string
2224  *
2225  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2226  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2227  * a binary buffer that generated by vbin_printf.
2228  *
2229  * The format follows C99 vsnprintf, but has some extensions:
2230  *  see vsnprintf comment for details.
2231  *
2232  * The return value is the number of characters which would
2233  * be generated for the given input, excluding the trailing
2234  * '\0', as per ISO C99. If you want to have the exact
2235  * number of characters written into @buf as return value
2236  * (not including the trailing '\0'), use vscnprintf(). If the
2237  * return is greater than or equal to @size, the resulting
2238  * string is truncated.
2239  */
2240 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2241 {
2242         struct printf_spec spec = {0};
2243         char *str, *end;
2244         const char *args = (const char *)bin_buf;
2245 
2246         if (WARN_ON_ONCE((int) size < 0))
2247                 return 0;
2248 
2249         str = buf;
2250         end = buf + size;
2251 
2252 #define get_arg(type)                                                   \
2253 ({                                                                      \
2254         typeof(type) value;                                             \
2255         if (sizeof(type) == 8) {                                        \
2256                 args = PTR_ALIGN(args, sizeof(u32));                    \
2257                 *(u32 *)&value = *(u32 *)args;                          \
2258                 *((u32 *)&value + 1) = *(u32 *)(args + 4);              \
2259         } else {                                                        \
2260                 args = PTR_ALIGN(args, sizeof(type));                   \
2261                 value = *(typeof(type) *)args;                          \
2262         }                                                               \
2263         args += sizeof(type);                                           \
2264         value;                                                          \
2265 })
2266 
2267         /* Make sure end is always >= buf */
2268         if (end < buf) {
2269                 end = ((void *)-1);
2270                 size = end - buf;
2271         }
2272 
2273         while (*fmt) {
2274                 const char *old_fmt = fmt;
2275                 int read = format_decode(fmt, &spec);
2276 
2277                 fmt += read;
2278 
2279                 switch (spec.type) {
2280                 case FORMAT_TYPE_NONE: {
2281                         int copy = read;
2282                         if (str < end) {
2283                                 if (copy > end - str)
2284                                         copy = end - str;
2285                                 memcpy(str, old_fmt, copy);
2286                         }
2287                         str += read;
2288                         break;
2289                 }
2290 
2291                 case FORMAT_TYPE_WIDTH:
2292                         spec.field_width = get_arg(int);
2293                         break;
2294 
2295                 case FORMAT_TYPE_PRECISION:
2296                         spec.precision = get_arg(int);
2297                         break;
2298 
2299                 case FORMAT_TYPE_CHAR: {
2300                         char c;
2301 
2302                         if (!(spec.flags & LEFT)) {
2303                                 while (--spec.field_width > 0) {
2304                                         if (str < end)
2305                                                 *str = ' ';
2306                                         ++str;
2307                                 }
2308                         }
2309                         c = (unsigned char) get_arg(char);
2310                         if (str < end)
2311                                 *str = c;
2312                         ++str;
2313                         while (--spec.field_width > 0) {
2314                                 if (str < end)
2315                                         *str = ' ';
2316                                 ++str;
2317                         }
2318                         break;
2319                 }
2320 
2321                 case FORMAT_TYPE_STR: {
2322                         const char *str_arg = args;
2323                         args += strlen(str_arg) + 1;
2324                         str = string(str, end, (char *)str_arg, spec);
2325                         break;
2326                 }
2327 
2328                 case FORMAT_TYPE_PTR:
2329                         str = pointer(fmt, str, end, get_arg(void *), spec);
2330                         while (isalnum(*fmt))
2331                                 fmt++;
2332                         break;
2333 
2334                 case FORMAT_TYPE_PERCENT_CHAR:
2335                 case FORMAT_TYPE_INVALID:
2336                         if (str < end)
2337                                 *str = '%';
2338                         ++str;
2339                         break;
2340 
2341                 default: {
2342                         unsigned long long num;
2343 
2344                         switch (spec.type) {
2345 
2346                         case FORMAT_TYPE_LONG_LONG:
2347                                 num = get_arg(long long);
2348                                 break;
2349                         case FORMAT_TYPE_ULONG:
2350                         case FORMAT_TYPE_LONG:
2351                                 num = get_arg(unsigned long);
2352                                 break;
2353                         case FORMAT_TYPE_SIZE_T:
2354                                 num = get_arg(size_t);
2355                                 break;
2356                         case FORMAT_TYPE_PTRDIFF:
2357                                 num = get_arg(ptrdiff_t);
2358                                 break;
2359                         case FORMAT_TYPE_UBYTE:
2360                                 num = get_arg(unsigned char);
2361                                 break;
2362                         case FORMAT_TYPE_BYTE:
2363                                 num = get_arg(signed char);
2364                                 break;
2365                         case FORMAT_TYPE_USHORT:
2366                                 num = get_arg(unsigned short);
2367                                 break;
2368                         case FORMAT_TYPE_SHORT:
2369                                 num = get_arg(short);
2370                                 break;
2371                         case FORMAT_TYPE_UINT:
2372                                 num = get_arg(unsigned int);
2373                                 break;
2374                         default:
2375                                 num = get_arg(int);
2376                         }
2377 
2378                         str = number(str, end, num, spec);
2379                 } /* default: */
2380                 } /* switch(spec.type) */
2381         } /* while(*fmt) */
2382 
2383         if (size > 0) {
2384                 if (str < end)
2385                         *str = '\0';
2386                 else
2387                         end[-1] = '\0';
2388         }
2389 
2390 #undef get_arg
2391 
2392         /* the trailing null byte doesn't count towards the total */
2393         return str - buf;
2394 }
2395 EXPORT_SYMBOL_GPL(bstr_printf);
2396 
2397 /**
2398  * bprintf - Parse a format string and place args' binary value in a buffer
2399  * @bin_buf: The buffer to place args' binary value
2400  * @size: The size of the buffer(by words(32bits), not characters)
2401  * @fmt: The format string to use
2402  * @...: Arguments for the format string
2403  *
2404  * The function returns the number of words(u32) written
2405  * into @bin_buf.
2406  */
2407 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2408 {
2409         va_list args;
2410         int ret;
2411 
2412         va_start(args, fmt);
2413         ret = vbin_printf(bin_buf, size, fmt, args);
2414         va_end(args);
2415 
2416         return ret;
2417 }
2418 EXPORT_SYMBOL_GPL(bprintf);
2419 
2420 #endif /* CONFIG_BINARY_PRINTF */
2421 
2422 /**
2423  * vsscanf - Unformat a buffer into a list of arguments
2424  * @buf:        input buffer
2425  * @fmt:        format of buffer
2426  * @args:       arguments
2427  */
2428 int vsscanf(const char *buf, const char *fmt, va_list args)
2429 {
2430         const char *str = buf;
2431         char *next;
2432         char digit;
2433         int num = 0;
2434         u8 qualifier;
2435         unsigned int base;
2436         union {
2437                 long long s;
2438                 unsigned long long u;
2439         } val;
2440         s16 field_width;
2441         bool is_sign;
2442 
2443         while (*fmt) {
2444                 /* skip any white space in format */
2445                 /* white space in format matchs any amount of
2446                  * white space, including none, in the input.
2447                  */
2448                 if (isspace(*fmt)) {
2449                         fmt = skip_spaces(++fmt);
2450                         str = skip_spaces(str);
2451                 }
2452 
2453                 /* anything that is not a conversion must match exactly */
2454                 if (*fmt != '%' && *fmt) {
2455                         if (*fmt++ != *str++)
2456                                 break;
2457                         continue;
2458                 }
2459 
2460                 if (!*fmt)
2461                         break;
2462                 ++fmt;
2463 
2464                 /* skip this conversion.
2465                  * advance both strings to next white space
2466                  */
2467                 if (*fmt == '*') {
2468                         if (!*str)
2469                                 break;
2470                         while (!isspace(*fmt) && *fmt != '%' && *fmt)
2471                                 fmt++;
2472                         while (!isspace(*str) && *str)
2473                                 str++;
2474                         continue;
2475                 }
2476 
2477                 /* get field width */
2478                 field_width = -1;
2479                 if (isdigit(*fmt)) {
2480                         field_width = skip_atoi(&fmt);
2481                         if (field_width <= 0)
2482                                 break;
2483                 }
2484 
2485                 /* get conversion qualifier */
2486                 qualifier = -1;
2487                 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2488                     _tolower(*fmt) == 'z') {
2489                         qualifier = *fmt++;
2490                         if (unlikely(qualifier == *fmt)) {
2491                                 if (qualifier == 'h') {
2492                                         qualifier = 'H';
2493                                         fmt++;
2494                                 } else if (qualifier == 'l') {
2495                                         qualifier = 'L';
2496                                         fmt++;
2497                                 }
2498                         }
2499                 }
2500 
2501                 if (!*fmt)
2502                         break;
2503 
2504                 if (*fmt == 'n') {
2505                         /* return number of characters read so far */
2506                         *va_arg(args, int *) = str - buf;
2507                         ++fmt;
2508                         continue;
2509                 }
2510 
2511                 if (!*str)
2512                         break;
2513 
2514                 base = 10;
2515                 is_sign = false;
2516 
2517                 switch (*fmt++) {
2518                 case 'c':
2519                 {
2520                         char *s = (char *)va_arg(args, char*);
2521                         if (field_width == -1)
2522                                 field_width = 1;
2523                         do {
2524                                 *s++ = *str++;
2525                         } while (--field_width > 0 && *str);
2526                         num++;
2527                 }
2528                 continue;
2529                 case 's':
2530                 {
2531                         char *s = (char *)va_arg(args, char *);
2532                         if (field_width == -1)
2533                                 field_width = SHRT_MAX;
2534                         /* first, skip leading white space in buffer */
2535                         str = skip_spaces(str);
2536 
2537                         /* now copy until next white space */
2538                         while (*str && !isspace(*str) && field_width--)
2539                                 *s++ = *str++;
2540                         *s = '\0';
2541                         num++;
2542                 }
2543                 continue;
2544                 case 'o':
2545                         base = 8;
2546                         break;
2547                 case 'x':
2548                 case 'X':
2549                         base = 16;
2550                         break;
2551                 case 'i':
2552                         base = 0;
2553                 case 'd':
2554                         is_sign = true;
2555                 case 'u':
2556                         break;
2557                 case '%':
2558                         /* looking for '%' in str */
2559                         if (*str++ != '%')
2560                                 return num;
2561                         continue;
2562                 default:
2563                         /* invalid format; stop here */
2564                         return num;
2565                 }
2566 
2567                 /* have some sort of integer conversion.
2568                  * first, skip white space in buffer.
2569                  */
2570                 str = skip_spaces(str);
2571 
2572                 digit = *str;
2573                 if (is_sign && digit == '-')
2574                         digit = *(str + 1);
2575 
2576                 if (!digit
2577                     || (base == 16 && !isxdigit(digit))
2578                     || (base == 10 && !isdigit(digit))
2579                     || (base == 8 && (!isdigit(digit) || digit > '7'))
2580                     || (base == 0 && !isdigit(digit)))
2581                         break;
2582 
2583                 if (is_sign)
2584                         val.s = qualifier != 'L' ?
2585                                 simple_strtol(str, &next, base) :
2586                                 simple_strtoll(str, &next, base);
2587                 else
2588                         val.u = qualifier != 'L' ?
2589                                 simple_strtoul(str, &next, base) :
2590                                 simple_strtoull(str, &next, base);
2591 
2592                 if (field_width > 0 && next - str > field_width) {
2593                         if (base == 0)
2594                                 _parse_integer_fixup_radix(str, &base);
2595                         while (next - str > field_width) {
2596                                 if (is_sign)
2597                                         val.s = div_s64(val.s, base);
2598                                 else
2599                                         val.u = div_u64(val.u, base);
2600                                 --next;
2601                         }
2602                 }
2603 
2604                 switch (qualifier) {
2605                 case 'H':       /* that's 'hh' in format */
2606                         if (is_sign)
2607                                 *va_arg(args, signed char *) = val.s;
2608                         else
2609                                 *va_arg(args, unsigned char *) = val.u;
2610                         break;
2611                 case 'h':
2612                         if (is_sign)
2613                                 *va_arg(args, short *) = val.s;
2614                         else
2615                                 *va_arg(args, unsigned short *) = val.u;
2616                         break;
2617                 case 'l':
2618                         if (is_sign)
2619                                 *va_arg(args, long *) = val.s;
2620                         else
2621                                 *va_arg(args, unsigned long *) = val.u;
2622                         break;
2623                 case 'L':
2624                         if (is_sign)
2625                                 *va_arg(args, long long *) = val.s;
2626                         else
2627                                 *va_arg(args, unsigned long long *) = val.u;
2628                         break;
2629                 case 'Z':
2630                 case 'z':
2631                         *va_arg(args, size_t *) = val.u;
2632                         break;
2633                 default:
2634                         if (is_sign)
2635                                 *va_arg(args, int *) = val.s;
2636                         else
2637                                 *va_arg(args, unsigned int *) = val.u;
2638                         break;
2639                 }
2640                 num++;
2641 
2642                 if (!next)
2643                         break;
2644                 str = next;
2645         }
2646 
2647         return num;
2648 }
2649 EXPORT_SYMBOL(vsscanf);
2650 
2651 /**
2652  * sscanf - Unformat a buffer into a list of arguments
2653  * @buf:        input buffer
2654  * @fmt:        formatting of buffer
2655  * @...:        resulting arguments
2656  */
2657 int sscanf(const char *buf, const char *fmt, ...)
2658 {
2659         va_list args;
2660         int i;
2661 
2662         va_start(args, fmt);
2663         i = vsscanf(buf, fmt, args);
2664         va_end(args);
2665 
2666         return i;
2667 }
2668 EXPORT_SYMBOL(sscanf);
2669 

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