Root/lib/vsprintf.c

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44 * This function is obsolete.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69 * This function is obsolete.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83 * This function is obsolete.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

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