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

Linux/lib/vsprintf.c

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 48  * This function is obsolete.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 73  * This function is obsolete.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

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