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>
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/uaccess.h>
27#include <linux/ioport.h>
28#include <net/addrconf.h>
29
30#include <asm/page.h> /* for PAGE_SIZE */
31#include <asm/div64.h>
32#include <asm/sections.h> /* for dereference_function_descriptor() */
33
34/* Works only for digits and letters, but small and fast */
35#define TOLOWER(x) ((x) | 0x20)
36
37static unsigned int simple_guess_base(const char *cp)
38{
39    if (cp[0] == '0') {
40        if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
41            return 16;
42        else
43            return 8;
44    } else {
45        return 10;
46    }
47}
48
49/**
50 * simple_strtoull - convert a string to an unsigned long long
51 * @cp: The start of the string
52 * @endp: A pointer to the end of the parsed string will be placed here
53 * @base: The number base to use
54 */
55unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
56{
57    unsigned long long result = 0;
58
59    if (!base)
60        base = simple_guess_base(cp);
61
62    if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
63        cp += 2;
64
65    while (isxdigit(*cp)) {
66        unsigned int value;
67
68        value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
69        if (value >= base)
70            break;
71        result = result * base + value;
72        cp++;
73    }
74    if (endp)
75        *endp = (char *)cp;
76
77    return result;
78}
79EXPORT_SYMBOL(simple_strtoull);
80
81/**
82 * simple_strtoul - convert a string to an unsigned 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 */
87unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
88{
89    return simple_strtoull(cp, endp, base);
90}
91EXPORT_SYMBOL(simple_strtoul);
92
93/**
94 * simple_strtol - convert a string to a signed long
95 * @cp: The start of the string
96 * @endp: A pointer to the end of the parsed string will be placed here
97 * @base: The number base to use
98 */
99long simple_strtol(const char *cp, char **endp, unsigned int base)
100{
101    if (*cp == '-')
102        return -simple_strtoul(cp + 1, endp, base);
103
104    return simple_strtoul(cp, endp, base);
105}
106EXPORT_SYMBOL(simple_strtol);
107
108/**
109 * simple_strtoll - convert a string to a signed long long
110 * @cp: The start of the string
111 * @endp: A pointer to the end of the parsed string will be placed here
112 * @base: The number base to use
113 */
114long long simple_strtoll(const char *cp, char **endp, unsigned int base)
115{
116    if (*cp == '-')
117        return -simple_strtoull(cp + 1, endp, base);
118
119    return simple_strtoull(cp, endp, base);
120}
121EXPORT_SYMBOL(simple_strtoll);
122
123/**
124 * strict_strtoul - convert a string to an unsigned long strictly
125 * @cp: The string to be converted
126 * @base: The number base to use
127 * @res: The converted result value
128 *
129 * strict_strtoul converts a string to an unsigned long only if the
130 * string is really an unsigned long string, any string containing
131 * any invalid char at the tail will be rejected and -EINVAL is returned,
132 * only a newline char at the tail is acceptible because people generally
133 * change a module parameter in the following way:
134 *
135 * echo 1024 > /sys/module/e1000/parameters/copybreak
136 *
137 * echo will append a newline to the tail.
138 *
139 * It returns 0 if conversion is successful and *res is set to the converted
140 * value, otherwise it returns -EINVAL and *res is set to 0.
141 *
142 * simple_strtoul just ignores the successive invalid characters and
143 * return the converted value of prefix part of the string.
144 */
145int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
146{
147    char *tail;
148    unsigned long val;
149
150    *res = 0;
151    if (!*cp)
152        return -EINVAL;
153
154    val = simple_strtoul(cp, &tail, base);
155    if (tail == cp)
156        return -EINVAL;
157
158    if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) {
159        *res = val;
160        return 0;
161    }
162
163    return -EINVAL;
164}
165EXPORT_SYMBOL(strict_strtoul);
166
167/**
168 * strict_strtol - convert a string to a long strictly
169 * @cp: The string to be converted
170 * @base: The number base to use
171 * @res: The converted result value
172 *
173 * strict_strtol is similiar to strict_strtoul, but it allows the first
174 * character of a string is '-'.
175 *
176 * It returns 0 if conversion is successful and *res is set to the converted
177 * value, otherwise it returns -EINVAL and *res is set to 0.
178 */
179int strict_strtol(const char *cp, unsigned int base, long *res)
180{
181    int ret;
182    if (*cp == '-') {
183        ret = strict_strtoul(cp + 1, base, (unsigned long *)res);
184        if (!ret)
185            *res = -(*res);
186    } else {
187        ret = strict_strtoul(cp, base, (unsigned long *)res);
188    }
189
190    return ret;
191}
192EXPORT_SYMBOL(strict_strtol);
193
194/**
195 * strict_strtoull - convert a string to an unsigned long long strictly
196 * @cp: The string to be converted
197 * @base: The number base to use
198 * @res: The converted result value
199 *
200 * strict_strtoull converts a string to an unsigned long long only if the
201 * string is really an unsigned long long string, any string containing
202 * any invalid char at the tail will be rejected and -EINVAL is returned,
203 * only a newline char at the tail is acceptible because people generally
204 * change a module parameter in the following way:
205 *
206 * echo 1024 > /sys/module/e1000/parameters/copybreak
207 *
208 * echo will append a newline to the tail of the string.
209 *
210 * It returns 0 if conversion is successful and *res is set to the converted
211 * value, otherwise it returns -EINVAL and *res is set to 0.
212 *
213 * simple_strtoull just ignores the successive invalid characters and
214 * return the converted value of prefix part of the string.
215 */
216int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
217{
218    char *tail;
219    unsigned long long val;
220
221    *res = 0;
222    if (!*cp)
223        return -EINVAL;
224
225    val = simple_strtoull(cp, &tail, base);
226    if (tail == cp)
227        return -EINVAL;
228    if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) {
229        *res = val;
230        return 0;
231    }
232
233    return -EINVAL;
234}
235EXPORT_SYMBOL(strict_strtoull);
236
237/**
238 * strict_strtoll - convert a string to a long long strictly
239 * @cp: The string to be converted
240 * @base: The number base to use
241 * @res: The converted result value
242 *
243 * strict_strtoll is similiar to strict_strtoull, but it allows the first
244 * character of a string is '-'.
245 *
246 * It returns 0 if conversion is successful and *res is set to the converted
247 * value, otherwise it returns -EINVAL and *res is set to 0.
248 */
249int strict_strtoll(const char *cp, unsigned int base, long long *res)
250{
251    int ret;
252    if (*cp == '-') {
253        ret = strict_strtoull(cp + 1, base, (unsigned long long *)res);
254        if (!ret)
255            *res = -(*res);
256    } else {
257        ret = strict_strtoull(cp, base, (unsigned long long *)res);
258    }
259
260    return ret;
261}
262EXPORT_SYMBOL(strict_strtoll);
263
264static noinline_for_stack
265int skip_atoi(const char **s)
266{
267    int i = 0;
268
269    while (isdigit(**s))
270        i = i*10 + *((*s)++) - '0';
271
272    return i;
273}
274
275/* Decimal conversion is by far the most typical, and is used
276 * for /proc and /sys data. This directly impacts e.g. top performance
277 * with many processes running. We optimize it for speed
278 * using code from
279 * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
280 * (with permission from the author, Douglas W. Jones). */
281
282/* Formats correctly any integer in [0,99999].
283 * Outputs from one to five digits depending on input.
284 * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
285static noinline_for_stack
286char *put_dec_trunc(char *buf, unsigned q)
287{
288    unsigned d3, d2, d1, d0;
289    d1 = (q>>4) & 0xf;
290    d2 = (q>>8) & 0xf;
291    d3 = (q>>12);
292
293    d0 = 6*(d3 + d2 + d1) + (q & 0xf);
294    q = (d0 * 0xcd) >> 11;
295    d0 = d0 - 10*q;
296    *buf++ = d0 + '0'; /* least significant digit */
297    d1 = q + 9*d3 + 5*d2 + d1;
298    if (d1 != 0) {
299        q = (d1 * 0xcd) >> 11;
300        d1 = d1 - 10*q;
301        *buf++ = d1 + '0'; /* next digit */
302
303        d2 = q + 2*d2;
304        if ((d2 != 0) || (d3 != 0)) {
305            q = (d2 * 0xd) >> 7;
306            d2 = d2 - 10*q;
307            *buf++ = d2 + '0'; /* next digit */
308
309            d3 = q + 4*d3;
310            if (d3 != 0) {
311                q = (d3 * 0xcd) >> 11;
312                d3 = d3 - 10*q;
313                *buf++ = d3 + '0'; /* next digit */
314                if (q != 0)
315                    *buf++ = q + '0'; /* most sign. digit */
316            }
317        }
318    }
319
320    return buf;
321}
322/* Same with if's removed. Always emits five digits */
323static noinline_for_stack
324char *put_dec_full(char *buf, unsigned q)
325{
326    /* BTW, if q is in [0,9999], 8-bit ints will be enough, */
327    /* but anyway, gcc produces better code with full-sized ints */
328    unsigned d3, d2, d1, d0;
329    d1 = (q>>4) & 0xf;
330    d2 = (q>>8) & 0xf;
331    d3 = (q>>12);
332
333    /*
334     * Possible ways to approx. divide by 10
335     * gcc -O2 replaces multiply with shifts and adds
336     * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
337     * (x * 0x67) >> 10: 1100111
338     * (x * 0x34) >> 9: 110100 - same
339     * (x * 0x1a) >> 8: 11010 - same
340     * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
341     */
342    d0 = 6*(d3 + d2 + d1) + (q & 0xf);
343    q = (d0 * 0xcd) >> 11;
344    d0 = d0 - 10*q;
345    *buf++ = d0 + '0';
346    d1 = q + 9*d3 + 5*d2 + d1;
347        q = (d1 * 0xcd) >> 11;
348        d1 = d1 - 10*q;
349        *buf++ = d1 + '0';
350
351        d2 = q + 2*d2;
352            q = (d2 * 0xd) >> 7;
353            d2 = d2 - 10*q;
354            *buf++ = d2 + '0';
355
356            d3 = q + 4*d3;
357                q = (d3 * 0xcd) >> 11; /* - shorter code */
358                /* q = (d3 * 0x67) >> 10; - would also work */
359                d3 = d3 - 10*q;
360                *buf++ = d3 + '0';
361                    *buf++ = q + '0';
362
363    return buf;
364}
365/* No inlining helps gcc to use registers better */
366static noinline_for_stack
367char *put_dec(char *buf, unsigned long long num)
368{
369    while (1) {
370        unsigned rem;
371        if (num < 100000)
372            return put_dec_trunc(buf, num);
373        rem = do_div(num, 100000);
374        buf = put_dec_full(buf, rem);
375    }
376}
377
378#define ZEROPAD 1 /* pad with zero */
379#define SIGN 2 /* unsigned/signed long */
380#define PLUS 4 /* show plus */
381#define SPACE 8 /* space if plus */
382#define LEFT 16 /* left justified */
383#define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
384#define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
385
386enum format_type {
387    FORMAT_TYPE_NONE, /* Just a string part */
388    FORMAT_TYPE_WIDTH,
389    FORMAT_TYPE_PRECISION,
390    FORMAT_TYPE_CHAR,
391    FORMAT_TYPE_STR,
392    FORMAT_TYPE_PTR,
393    FORMAT_TYPE_PERCENT_CHAR,
394    FORMAT_TYPE_INVALID,
395    FORMAT_TYPE_LONG_LONG,
396    FORMAT_TYPE_ULONG,
397    FORMAT_TYPE_LONG,
398    FORMAT_TYPE_UBYTE,
399    FORMAT_TYPE_BYTE,
400    FORMAT_TYPE_USHORT,
401    FORMAT_TYPE_SHORT,
402    FORMAT_TYPE_UINT,
403    FORMAT_TYPE_INT,
404    FORMAT_TYPE_NRCHARS,
405    FORMAT_TYPE_SIZE_T,
406    FORMAT_TYPE_PTRDIFF
407};
408
409struct printf_spec {
410    u8 type; /* format_type enum */
411    u8 flags; /* flags to number() */
412    u8 base; /* number base, 8, 10 or 16 only */
413    u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */
414    s16 field_width; /* width of output field */
415    s16 precision; /* # of digits/chars */
416};
417
418static noinline_for_stack
419char *number(char *buf, char *end, unsigned long long num,
420         struct printf_spec spec)
421{
422    /* we are called with base 8, 10 or 16, only, thus don't need "G..." */
423    static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
424
425    char tmp[66];
426    char sign;
427    char locase;
428    int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
429    int i;
430
431    /* locase = 0 or 0x20. ORing digits or letters with 'locase'
432     * produces same digits or (maybe lowercased) letters */
433    locase = (spec.flags & SMALL);
434    if (spec.flags & LEFT)
435        spec.flags &= ~ZEROPAD;
436    sign = 0;
437    if (spec.flags & SIGN) {
438        if ((signed long long)num < 0) {
439            sign = '-';
440            num = -(signed long long)num;
441            spec.field_width--;
442        } else if (spec.flags & PLUS) {
443            sign = '+';
444            spec.field_width--;
445        } else if (spec.flags & SPACE) {
446            sign = ' ';
447            spec.field_width--;
448        }
449    }
450    if (need_pfx) {
451        spec.field_width--;
452        if (spec.base == 16)
453            spec.field_width--;
454    }
455
456    /* generate full string in tmp[], in reverse order */
457    i = 0;
458    if (num == 0)
459        tmp[i++] = '0';
460    /* Generic code, for any base:
461    else do {
462        tmp[i++] = (digits[do_div(num,base)] | locase);
463    } while (num != 0);
464    */
465    else if (spec.base != 10) { /* 8 or 16 */
466        int mask = spec.base - 1;
467        int shift = 3;
468
469        if (spec.base == 16)
470            shift = 4;
471        do {
472            tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
473            num >>= shift;
474        } while (num);
475    } else { /* base 10 */
476        i = put_dec(tmp, num) - tmp;
477    }
478
479    /* printing 100 using %2d gives "100", not "00" */
480    if (i > spec.precision)
481        spec.precision = i;
482    /* leading space padding */
483    spec.field_width -= spec.precision;
484    if (!(spec.flags & (ZEROPAD+LEFT))) {
485        while (--spec.field_width >= 0) {
486            if (buf < end)
487                *buf = ' ';
488            ++buf;
489        }
490    }
491    /* sign */
492    if (sign) {
493        if (buf < end)
494            *buf = sign;
495        ++buf;
496    }
497    /* "0x" / "0" prefix */
498    if (need_pfx) {
499        if (buf < end)
500            *buf = '0';
501        ++buf;
502        if (spec.base == 16) {
503            if (buf < end)
504                *buf = ('X' | locase);
505            ++buf;
506        }
507    }
508    /* zero or space padding */
509    if (!(spec.flags & LEFT)) {
510        char c = (spec.flags & ZEROPAD) ? '0' : ' ';
511        while (--spec.field_width >= 0) {
512            if (buf < end)
513                *buf = c;
514            ++buf;
515        }
516    }
517    /* hmm even more zero padding? */
518    while (i <= --spec.precision) {
519        if (buf < end)
520            *buf = '0';
521        ++buf;
522    }
523    /* actual digits of result */
524    while (--i >= 0) {
525        if (buf < end)
526            *buf = tmp[i];
527        ++buf;
528    }
529    /* trailing space padding */
530    while (--spec.field_width >= 0) {
531        if (buf < end)
532            *buf = ' ';
533        ++buf;
534    }
535
536    return buf;
537}
538
539static noinline_for_stack
540char *string(char *buf, char *end, const char *s, struct printf_spec spec)
541{
542    int len, i;
543
544    if ((unsigned long)s < PAGE_SIZE)
545        s = "(null)";
546
547    len = strnlen(s, spec.precision);
548
549    if (!(spec.flags & LEFT)) {
550        while (len < spec.field_width--) {
551            if (buf < end)
552                *buf = ' ';
553            ++buf;
554        }
555    }
556    for (i = 0; i < len; ++i) {
557        if (buf < end)
558            *buf = *s;
559        ++buf; ++s;
560    }
561    while (len < spec.field_width--) {
562        if (buf < end)
563            *buf = ' ';
564        ++buf;
565    }
566
567    return buf;
568}
569
570static noinline_for_stack
571char *symbol_string(char *buf, char *end, void *ptr,
572            struct printf_spec spec, char ext)
573{
574    unsigned long value = (unsigned long) ptr;
575#ifdef CONFIG_KALLSYMS
576    char sym[KSYM_SYMBOL_LEN];
577    if (ext != 'f' && ext != 's')
578        sprint_symbol(sym, value);
579    else
580        kallsyms_lookup(value, NULL, NULL, NULL, sym);
581
582    return string(buf, end, sym, spec);
583#else
584    spec.field_width = 2 * sizeof(void *);
585    spec.flags |= SPECIAL | SMALL | ZEROPAD;
586    spec.base = 16;
587
588    return number(buf, end, value, spec);
589#endif
590}
591
592static noinline_for_stack
593char *resource_string(char *buf, char *end, struct resource *res,
594              struct printf_spec spec, const char *fmt)
595{
596#ifndef IO_RSRC_PRINTK_SIZE
597#define IO_RSRC_PRINTK_SIZE 6
598#endif
599
600#ifndef MEM_RSRC_PRINTK_SIZE
601#define MEM_RSRC_PRINTK_SIZE 10
602#endif
603    static const struct printf_spec io_spec = {
604        .base = 16,
605        .field_width = IO_RSRC_PRINTK_SIZE,
606        .precision = -1,
607        .flags = SPECIAL | SMALL | ZEROPAD,
608    };
609    static const struct printf_spec mem_spec = {
610        .base = 16,
611        .field_width = MEM_RSRC_PRINTK_SIZE,
612        .precision = -1,
613        .flags = SPECIAL | SMALL | ZEROPAD,
614    };
615    static const struct printf_spec bus_spec = {
616        .base = 16,
617        .field_width = 2,
618        .precision = -1,
619        .flags = SMALL | ZEROPAD,
620    };
621    static const struct printf_spec dec_spec = {
622        .base = 10,
623        .precision = -1,
624        .flags = 0,
625    };
626    static const struct printf_spec str_spec = {
627        .field_width = -1,
628        .precision = 10,
629        .flags = LEFT,
630    };
631    static const struct printf_spec flag_spec = {
632        .base = 16,
633        .precision = -1,
634        .flags = SPECIAL | SMALL,
635    };
636
637    /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
638     * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
639#define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
640#define FLAG_BUF_SIZE (2 * sizeof(res->flags))
641#define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
642#define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
643    char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
644             2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
645
646    char *p = sym, *pend = sym + sizeof(sym);
647    int decode = (fmt[0] == 'R') ? 1 : 0;
648    const struct printf_spec *specp;
649
650    *p++ = '[';
651    if (res->flags & IORESOURCE_IO) {
652        p = string(p, pend, "io ", str_spec);
653        specp = &io_spec;
654    } else if (res->flags & IORESOURCE_MEM) {
655        p = string(p, pend, "mem ", str_spec);
656        specp = &mem_spec;
657    } else if (res->flags & IORESOURCE_IRQ) {
658        p = string(p, pend, "irq ", str_spec);
659        specp = &dec_spec;
660    } else if (res->flags & IORESOURCE_DMA) {
661        p = string(p, pend, "dma ", str_spec);
662        specp = &dec_spec;
663    } else if (res->flags & IORESOURCE_BUS) {
664        p = string(p, pend, "bus ", str_spec);
665        specp = &bus_spec;
666    } else {
667        p = string(p, pend, "??? ", str_spec);
668        specp = &mem_spec;
669        decode = 0;
670    }
671    p = number(p, pend, res->start, *specp);
672    if (res->start != res->end) {
673        *p++ = '-';
674        p = number(p, pend, res->end, *specp);
675    }
676    if (decode) {
677        if (res->flags & IORESOURCE_MEM_64)
678            p = string(p, pend, " 64bit", str_spec);
679        if (res->flags & IORESOURCE_PREFETCH)
680            p = string(p, pend, " pref", str_spec);
681        if (res->flags & IORESOURCE_WINDOW)
682            p = string(p, pend, " window", str_spec);
683        if (res->flags & IORESOURCE_DISABLED)
684            p = string(p, pend, " disabled", str_spec);
685    } else {
686        p = string(p, pend, " flags ", str_spec);
687        p = number(p, pend, res->flags, flag_spec);
688    }
689    *p++ = ']';
690    *p = '\0';
691
692    return string(buf, end, sym, spec);
693}
694
695static noinline_for_stack
696char *mac_address_string(char *buf, char *end, u8 *addr,
697             struct printf_spec spec, const char *fmt)
698{
699    char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
700    char *p = mac_addr;
701    int i;
702    char separator;
703
704    if (fmt[1] == 'F') { /* FDDI canonical format */
705        separator = '-';
706    } else {
707        separator = ':';
708    }
709
710    for (i = 0; i < 6; i++) {
711        p = pack_hex_byte(p, addr[i]);
712        if (fmt[0] == 'M' && i != 5)
713            *p++ = separator;
714    }
715    *p = '\0';
716
717    return string(buf, end, mac_addr, spec);
718}
719
720static noinline_for_stack
721char *ip4_string(char *p, const u8 *addr, const char *fmt)
722{
723    int i;
724    bool leading_zeros = (fmt[0] == 'i');
725    int index;
726    int step;
727
728    switch (fmt[2]) {
729    case 'h':
730#ifdef __BIG_ENDIAN
731        index = 0;
732        step = 1;
733#else
734        index = 3;
735        step = -1;
736#endif
737        break;
738    case 'l':
739        index = 3;
740        step = -1;
741        break;
742    case 'n':
743    case 'b':
744    default:
745        index = 0;
746        step = 1;
747        break;
748    }
749    for (i = 0; i < 4; i++) {
750        char temp[3]; /* hold each IP quad in reverse order */
751        int digits = put_dec_trunc(temp, addr[index]) - temp;
752        if (leading_zeros) {
753            if (digits < 3)
754                *p++ = '0';
755            if (digits < 2)
756                *p++ = '0';
757        }
758        /* reverse the digits in the quad */
759        while (digits--)
760            *p++ = temp[digits];
761        if (i < 3)
762            *p++ = '.';
763        index += step;
764    }
765    *p = '\0';
766
767    return p;
768}
769
770static noinline_for_stack
771char *ip6_compressed_string(char *p, const char *addr)
772{
773    int i, j, range;
774    unsigned char zerolength[8];
775    int longest = 1;
776    int colonpos = -1;
777    u16 word;
778    u8 hi, lo;
779    bool needcolon = false;
780    bool useIPv4;
781    struct in6_addr in6;
782
783    memcpy(&in6, addr, sizeof(struct in6_addr));
784
785    useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
786
787    memset(zerolength, 0, sizeof(zerolength));
788
789    if (useIPv4)
790        range = 6;
791    else
792        range = 8;
793
794    /* find position of longest 0 run */
795    for (i = 0; i < range; i++) {
796        for (j = i; j < range; j++) {
797            if (in6.s6_addr16[j] != 0)
798                break;
799            zerolength[i]++;
800        }
801    }
802    for (i = 0; i < range; i++) {
803        if (zerolength[i] > longest) {
804            longest = zerolength[i];
805            colonpos = i;
806        }
807    }
808
809    /* emit address */
810    for (i = 0; i < range; i++) {
811        if (i == colonpos) {
812            if (needcolon || i == 0)
813                *p++ = ':';
814            *p++ = ':';
815            needcolon = false;
816            i += longest - 1;
817            continue;
818        }
819        if (needcolon) {
820            *p++ = ':';
821            needcolon = false;
822        }
823        /* hex u16 without leading 0s */
824        word = ntohs(in6.s6_addr16[i]);
825        hi = word >> 8;
826        lo = word & 0xff;
827        if (hi) {
828            if (hi > 0x0f)
829                p = pack_hex_byte(p, hi);
830            else
831                *p++ = hex_asc_lo(hi);
832            p = pack_hex_byte(p, lo);
833        }
834        else if (lo > 0x0f)
835            p = pack_hex_byte(p, lo);
836        else
837            *p++ = hex_asc_lo(lo);
838        needcolon = true;
839    }
840
841    if (useIPv4) {
842        if (needcolon)
843            *p++ = ':';
844        p = ip4_string(p, &in6.s6_addr[12], "I4");
845    }
846    *p = '\0';
847
848    return p;
849}
850
851static noinline_for_stack
852char *ip6_string(char *p, const char *addr, const char *fmt)
853{
854    int i;
855
856    for (i = 0; i < 8; i++) {
857        p = pack_hex_byte(p, *addr++);
858        p = pack_hex_byte(p, *addr++);
859        if (fmt[0] == 'I' && i != 7)
860            *p++ = ':';
861    }
862    *p = '\0';
863
864    return p;
865}
866
867static noinline_for_stack
868char *ip6_addr_string(char *buf, char *end, const u8 *addr,
869              struct printf_spec spec, const char *fmt)
870{
871    char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
872
873    if (fmt[0] == 'I' && fmt[2] == 'c')
874        ip6_compressed_string(ip6_addr, addr);
875    else
876        ip6_string(ip6_addr, addr, fmt);
877
878    return string(buf, end, ip6_addr, spec);
879}
880
881static noinline_for_stack
882char *ip4_addr_string(char *buf, char *end, const u8 *addr,
883              struct printf_spec spec, const char *fmt)
884{
885    char ip4_addr[sizeof("255.255.255.255")];
886
887    ip4_string(ip4_addr, addr, fmt);
888
889    return string(buf, end, ip4_addr, spec);
890}
891
892static noinline_for_stack
893char *uuid_string(char *buf, char *end, const u8 *addr,
894          struct printf_spec spec, const char *fmt)
895{
896    char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];
897    char *p = uuid;
898    int i;
899    static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
900    static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
901    const u8 *index = be;
902    bool uc = false;
903
904    switch (*(++fmt)) {
905    case 'L':
906        uc = true; /* fall-through */
907    case 'l':
908        index = le;
909        break;
910    case 'B':
911        uc = true;
912        break;
913    }
914
915    for (i = 0; i < 16; i++) {
916        p = pack_hex_byte(p, addr[index[i]]);
917        switch (i) {
918        case 3:
919        case 5:
920        case 7:
921        case 9:
922            *p++ = '-';
923            break;
924        }
925    }
926
927    *p = 0;
928
929    if (uc) {
930        p = uuid;
931        do {
932            *p = toupper(*p);
933        } while (*(++p));
934    }
935
936    return string(buf, end, uuid, spec);
937}
938
939/*
940 * Show a '%p' thing. A kernel extension is that the '%p' is followed
941 * by an extra set of alphanumeric characters that are extended format
942 * specifiers.
943 *
944 * Right now we handle:
945 *
946 * - 'F' For symbolic function descriptor pointers with offset
947 * - 'f' For simple symbolic function names without offset
948 * - 'S' For symbolic direct pointers with offset
949 * - 's' For symbolic direct pointers without offset
950 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
951 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
952 * - 'M' For a 6-byte MAC address, it prints the address in the
953 * usual colon-separated hex notation
954 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
955 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
956 * with a dash-separated hex notation
957 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
958 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
959 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
960 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
961 * IPv6 omits the colons (01020304...0f)
962 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
963 * - '[Ii]4[hnbl]' IPv4 addresses in host, network, big or little endian order
964 * - 'I6c' for IPv6 addresses printed as specified by
965 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
966 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
967 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
968 * Options for %pU are:
969 * b big endian lower case hex (default)
970 * B big endian UPPER case hex
971 * l little endian lower case hex
972 * L little endian UPPER case hex
973 * big endian output byte order is:
974 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
975 * little endian output byte order is:
976 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
977 * - 'V' For a struct va_format which contains a format string * and va_list *,
978 * call vsnprintf(->format, *->va_list).
979 * Implements a "recursive vsnprintf".
980 * Do not use this feature without some mechanism to verify the
981 * correctness of the format string and va_list arguments.
982 *
983 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
984 * function pointers are really function descriptors, which contain a
985 * pointer to the real address.
986 */
987static noinline_for_stack
988char *pointer(const char *fmt, char *buf, char *end, void *ptr,
989          struct printf_spec spec)
990{
991    if (!ptr)
992        return string(buf, end, "(null)", spec);
993
994    switch (*fmt) {
995    case 'F':
996    case 'f':
997        ptr = dereference_function_descriptor(ptr);
998        /* Fallthrough */
999    case 'S':
1000    case 's':
1001        return symbol_string(buf, end, ptr, spec, *fmt);
1002    case 'R':
1003    case 'r':
1004        return resource_string(buf, end, ptr, spec, fmt);
1005    case 'M': /* Colon separated: 00:01:02:03:04:05 */
1006    case 'm': /* Contiguous: 000102030405 */
1007                    /* [mM]F (FDDI, bit reversed) */
1008        return mac_address_string(buf, end, ptr, spec, fmt);
1009    case 'I': /* Formatted IP supported
1010                     * 4: 1.2.3.4
1011                     * 6: 0001:0203:...:0708
1012                     * 6c: 1::708 or 1::1.2.3.4
1013                     */
1014    case 'i': /* Contiguous:
1015                     * 4: 001.002.003.004
1016                     * 6: 000102...0f
1017                     */
1018        switch (fmt[1]) {
1019        case '6':
1020            return ip6_addr_string(buf, end, ptr, spec, fmt);
1021        case '4':
1022            return ip4_addr_string(buf, end, ptr, spec, fmt);
1023        }
1024        break;
1025    case 'U':
1026        return uuid_string(buf, end, ptr, spec, fmt);
1027    case 'V':
1028        return buf + vsnprintf(buf, end - buf,
1029                       ((struct va_format *)ptr)->fmt,
1030                       *(((struct va_format *)ptr)->va));
1031    }
1032    spec.flags |= SMALL;
1033    if (spec.field_width == -1) {
1034        spec.field_width = 2*sizeof(void *);
1035        spec.flags |= ZEROPAD;
1036    }
1037    spec.base = 16;
1038
1039    return number(buf, end, (unsigned long) ptr, spec);
1040}
1041
1042/*
1043 * Helper function to decode printf style format.
1044 * Each call decode a token from the format and return the
1045 * number of characters read (or likely the delta where it wants
1046 * to go on the next call).
1047 * The decoded token is returned through the parameters
1048 *
1049 * 'h', 'l', or 'L' for integer fields
1050 * 'z' support added 23/7/1999 S.H.
1051 * 'z' changed to 'Z' --davidm 1/25/99
1052 * 't' added for ptrdiff_t
1053 *
1054 * @fmt: the format string
1055 * @type of the token returned
1056 * @flags: various flags such as +, -, # tokens..
1057 * @field_width: overwritten width
1058 * @base: base of the number (octal, hex, ...)
1059 * @precision: precision of a number
1060 * @qualifier: qualifier of a number (long, size_t, ...)
1061 */
1062static noinline_for_stack
1063int format_decode(const char *fmt, struct printf_spec *spec)
1064{
1065    const char *start = fmt;
1066
1067    /* we finished early by reading the field width */
1068    if (spec->type == FORMAT_TYPE_WIDTH) {
1069        if (spec->field_width < 0) {
1070            spec->field_width = -spec->field_width;
1071            spec->flags |= LEFT;
1072        }
1073        spec->type = FORMAT_TYPE_NONE;
1074        goto precision;
1075    }
1076
1077    /* we finished early by reading the precision */
1078    if (spec->type == FORMAT_TYPE_PRECISION) {
1079        if (spec->precision < 0)
1080            spec->precision = 0;
1081
1082        spec->type = FORMAT_TYPE_NONE;
1083        goto qualifier;
1084    }
1085
1086    /* By default */
1087    spec->type = FORMAT_TYPE_NONE;
1088
1089    for (; *fmt ; ++fmt) {
1090        if (*fmt == '%')
1091            break;
1092    }
1093
1094    /* Return the current non-format string */
1095    if (fmt != start || !*fmt)
1096        return fmt - start;
1097
1098    /* Process flags */
1099    spec->flags = 0;
1100
1101    while (1) { /* this also skips first '%' */
1102        bool found = true;
1103
1104        ++fmt;
1105
1106        switch (*fmt) {
1107        case '-': spec->flags |= LEFT; break;
1108        case '+': spec->flags |= PLUS; break;
1109        case ' ': spec->flags |= SPACE; break;
1110        case '#': spec->flags |= SPECIAL; break;
1111        case '0': spec->flags |= ZEROPAD; break;
1112        default: found = false;
1113        }
1114
1115        if (!found)
1116            break;
1117    }
1118
1119    /* get field width */
1120    spec->field_width = -1;
1121
1122    if (isdigit(*fmt))
1123        spec->field_width = skip_atoi(&fmt);
1124    else if (*fmt == '*') {
1125        /* it's the next argument */
1126        spec->type = FORMAT_TYPE_WIDTH;
1127        return ++fmt - start;
1128    }
1129
1130precision:
1131    /* get the precision */
1132    spec->precision = -1;
1133    if (*fmt == '.') {
1134        ++fmt;
1135        if (isdigit(*fmt)) {
1136            spec->precision = skip_atoi(&fmt);
1137            if (spec->precision < 0)
1138                spec->precision = 0;
1139        } else if (*fmt == '*') {
1140            /* it's the next argument */
1141            spec->type = FORMAT_TYPE_PRECISION;
1142            return ++fmt - start;
1143        }
1144    }
1145
1146qualifier:
1147    /* get the conversion qualifier */
1148    spec->qualifier = -1;
1149    if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1150        TOLOWER(*fmt) == 'z' || *fmt == 't') {
1151        spec->qualifier = *fmt++;
1152        if (unlikely(spec->qualifier == *fmt)) {
1153            if (spec->qualifier == 'l') {
1154                spec->qualifier = 'L';
1155                ++fmt;
1156            } else if (spec->qualifier == 'h') {
1157                spec->qualifier = 'H';
1158                ++fmt;
1159            }
1160        }
1161    }
1162
1163    /* default base */
1164    spec->base = 10;
1165    switch (*fmt) {
1166    case 'c':
1167        spec->type = FORMAT_TYPE_CHAR;
1168        return ++fmt - start;
1169
1170    case 's':
1171        spec->type = FORMAT_TYPE_STR;
1172        return ++fmt - start;
1173
1174    case 'p':
1175        spec->type = FORMAT_TYPE_PTR;
1176        return fmt - start;
1177        /* skip alnum */
1178
1179    case 'n':
1180        spec->type = FORMAT_TYPE_NRCHARS;
1181        return ++fmt - start;
1182
1183    case '%':
1184        spec->type = FORMAT_TYPE_PERCENT_CHAR;
1185        return ++fmt - start;
1186
1187    /* integer number formats - set up the flags and "break" */
1188    case 'o':
1189        spec->base = 8;
1190        break;
1191
1192    case 'x':
1193        spec->flags |= SMALL;
1194
1195    case 'X':
1196        spec->base = 16;
1197        break;
1198
1199    case 'd':
1200    case 'i':
1201        spec->flags |= SIGN;
1202    case 'u':
1203        break;
1204
1205    default:
1206        spec->type = FORMAT_TYPE_INVALID;
1207        return fmt - start;
1208    }
1209
1210    if (spec->qualifier == 'L')
1211        spec->type = FORMAT_TYPE_LONG_LONG;
1212    else if (spec->qualifier == 'l') {
1213        if (spec->flags & SIGN)
1214            spec->type = FORMAT_TYPE_LONG;
1215        else
1216            spec->type = FORMAT_TYPE_ULONG;
1217    } else if (TOLOWER(spec->qualifier) == 'z') {
1218        spec->type = FORMAT_TYPE_SIZE_T;
1219    } else if (spec->qualifier == 't') {
1220        spec->type = FORMAT_TYPE_PTRDIFF;
1221    } else if (spec->qualifier == 'H') {
1222        if (spec->flags & SIGN)
1223            spec->type = FORMAT_TYPE_BYTE;
1224        else
1225            spec->type = FORMAT_TYPE_UBYTE;
1226    } else if (spec->qualifier == 'h') {
1227        if (spec->flags & SIGN)
1228            spec->type = FORMAT_TYPE_SHORT;
1229        else
1230            spec->type = FORMAT_TYPE_USHORT;
1231    } else {
1232        if (spec->flags & SIGN)
1233            spec->type = FORMAT_TYPE_INT;
1234        else
1235            spec->type = FORMAT_TYPE_UINT;
1236    }
1237
1238    return ++fmt - start;
1239}
1240
1241/**
1242 * vsnprintf - Format a string and place it in a buffer
1243 * @buf: The buffer to place the result into
1244 * @size: The size of the buffer, including the trailing null space
1245 * @fmt: The format string to use
1246 * @args: Arguments for the format string
1247 *
1248 * This function follows C99 vsnprintf, but has some extensions:
1249 * %pS output the name of a text symbol with offset
1250 * %ps output the name of a text symbol without offset
1251 * %pF output the name of a function pointer with its offset
1252 * %pf output the name of a function pointer without its offset
1253 * %pR output the address range in a struct resource with decoded flags
1254 * %pr output the address range in a struct resource with raw flags
1255 * %pM output a 6-byte MAC address with colons
1256 * %pm output a 6-byte MAC address without colons
1257 * %pI4 print an IPv4 address without leading zeros
1258 * %pi4 print an IPv4 address with leading zeros
1259 * %pI6 print an IPv6 address with colons
1260 * %pi6 print an IPv6 address without colons
1261 * %pI6c print an IPv6 address as specified by
1262 * http://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-00
1263 * %pU[bBlL] print a UUID/GUID in big or little endian using lower or upper
1264 * case.
1265 * %n is ignored
1266 *
1267 * The return value is the number of characters which would
1268 * be generated for the given input, excluding the trailing
1269 * '\0', as per ISO C99. If you want to have the exact
1270 * number of characters written into @buf as return value
1271 * (not including the trailing '\0'), use vscnprintf(). If the
1272 * return is greater than or equal to @size, the resulting
1273 * string is truncated.
1274 *
1275 * Call this function if you are already dealing with a va_list.
1276 * You probably want snprintf() instead.
1277 */
1278int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1279{
1280    unsigned long long num;
1281    char *str, *end;
1282    struct printf_spec spec = {0};
1283
1284    /* Reject out-of-range values early. Large positive sizes are
1285       used for unknown buffer sizes. */
1286    if (WARN_ON_ONCE((int) size < 0))
1287        return 0;
1288
1289    str = buf;
1290    end = buf + size;
1291
1292    /* Make sure end is always >= buf */
1293    if (end < buf) {
1294        end = ((void *)-1);
1295        size = end - buf;
1296    }
1297
1298    while (*fmt) {
1299        const char *old_fmt = fmt;
1300        int read = format_decode(fmt, &spec);
1301
1302        fmt += read;
1303
1304        switch (spec.type) {
1305        case FORMAT_TYPE_NONE: {
1306            int copy = read;
1307            if (str < end) {
1308                if (copy > end - str)
1309                    copy = end - str;
1310                memcpy(str, old_fmt, copy);
1311            }
1312            str += read;
1313            break;
1314        }
1315
1316        case FORMAT_TYPE_WIDTH:
1317            spec.field_width = va_arg(args, int);
1318            break;
1319
1320        case FORMAT_TYPE_PRECISION:
1321            spec.precision = va_arg(args, int);
1322            break;
1323
1324        case FORMAT_TYPE_CHAR: {
1325            char c;
1326
1327            if (!(spec.flags & LEFT)) {
1328                while (--spec.field_width > 0) {
1329                    if (str < end)
1330                        *str = ' ';
1331                    ++str;
1332
1333                }
1334            }
1335            c = (unsigned char) va_arg(args, int);
1336            if (str < end)
1337                *str = c;
1338            ++str;
1339            while (--spec.field_width > 0) {
1340                if (str < end)
1341                    *str = ' ';
1342                ++str;
1343            }
1344            break;
1345        }
1346
1347        case FORMAT_TYPE_STR:
1348            str = string(str, end, va_arg(args, char *), spec);
1349            break;
1350
1351        case FORMAT_TYPE_PTR:
1352            str = pointer(fmt+1, str, end, va_arg(args, void *),
1353                      spec);
1354            while (isalnum(*fmt))
1355                fmt++;
1356            break;
1357
1358        case FORMAT_TYPE_PERCENT_CHAR:
1359            if (str < end)
1360                *str = '%';
1361            ++str;
1362            break;
1363
1364        case FORMAT_TYPE_INVALID:
1365            if (str < end)
1366                *str = '%';
1367            ++str;
1368            break;
1369
1370        case FORMAT_TYPE_NRCHARS: {
1371            u8 qualifier = spec.qualifier;
1372
1373            if (qualifier == 'l') {
1374                long *ip = va_arg(args, long *);
1375                *ip = (str - buf);
1376            } else if (TOLOWER(qualifier) == 'z') {
1377                size_t *ip = va_arg(args, size_t *);
1378                *ip = (str - buf);
1379            } else {
1380                int *ip = va_arg(args, int *);
1381                *ip = (str - buf);
1382            }
1383            break;
1384        }
1385
1386        default:
1387            switch (spec.type) {
1388            case FORMAT_TYPE_LONG_LONG:
1389                num = va_arg(args, long long);
1390                break;
1391            case FORMAT_TYPE_ULONG:
1392                num = va_arg(args, unsigned long);
1393                break;
1394            case FORMAT_TYPE_LONG:
1395                num = va_arg(args, long);
1396                break;
1397            case FORMAT_TYPE_SIZE_T:
1398                num = va_arg(args, size_t);
1399                break;
1400            case FORMAT_TYPE_PTRDIFF:
1401                num = va_arg(args, ptrdiff_t);
1402                break;
1403            case FORMAT_TYPE_UBYTE:
1404                num = (unsigned char) va_arg(args, int);
1405                break;
1406            case FORMAT_TYPE_BYTE:
1407                num = (signed char) va_arg(args, int);
1408                break;
1409            case FORMAT_TYPE_USHORT:
1410                num = (unsigned short) va_arg(args, int);
1411                break;
1412            case FORMAT_TYPE_SHORT:
1413                num = (short) va_arg(args, int);
1414                break;
1415            case FORMAT_TYPE_INT:
1416                num = (int) va_arg(args, int);
1417                break;
1418            default:
1419                num = va_arg(args, unsigned int);
1420            }
1421
1422            str = number(str, end, num, spec);
1423        }
1424    }
1425
1426    if (size > 0) {
1427        if (str < end)
1428            *str = '\0';
1429        else
1430            end[-1] = '\0';
1431    }
1432
1433    /* the trailing null byte doesn't count towards the total */
1434    return str-buf;
1435
1436}
1437EXPORT_SYMBOL(vsnprintf);
1438
1439/**
1440 * vscnprintf - Format a string and place it in a buffer
1441 * @buf: The buffer to place the result into
1442 * @size: The size of the buffer, including the trailing null space
1443 * @fmt: The format string to use
1444 * @args: Arguments for the format string
1445 *
1446 * The return value is the number of characters which have been written into
1447 * the @buf not including the trailing '\0'. If @size is <= 0 the function
1448 * returns 0.
1449 *
1450 * Call this function if you are already dealing with a va_list.
1451 * You probably want scnprintf() instead.
1452 *
1453 * See the vsnprintf() documentation for format string extensions over C99.
1454 */
1455int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
1456{
1457    int i;
1458
1459    i = vsnprintf(buf, size, fmt, args);
1460
1461    return (i >= size) ? (size - 1) : i;
1462}
1463EXPORT_SYMBOL(vscnprintf);
1464
1465/**
1466 * snprintf - Format a string and place it in a buffer
1467 * @buf: The buffer to place the result into
1468 * @size: The size of the buffer, including the trailing null space
1469 * @fmt: The format string to use
1470 * @...: Arguments for the format string
1471 *
1472 * The return value is the number of characters which would be
1473 * generated for the given input, excluding the trailing null,
1474 * as per ISO C99. If the return is greater than or equal to
1475 * @size, the resulting string is truncated.
1476 *
1477 * See the vsnprintf() documentation for format string extensions over C99.
1478 */
1479int snprintf(char *buf, size_t size, const char *fmt, ...)
1480{
1481    va_list args;
1482    int i;
1483
1484    va_start(args, fmt);
1485    i = vsnprintf(buf, size, fmt, args);
1486    va_end(args);
1487
1488    return i;
1489}
1490EXPORT_SYMBOL(snprintf);
1491
1492/**
1493 * scnprintf - Format a string and place it in a buffer
1494 * @buf: The buffer to place the result into
1495 * @size: The size of the buffer, including the trailing null space
1496 * @fmt: The format string to use
1497 * @...: Arguments for the format string
1498 *
1499 * The return value is the number of characters written into @buf not including
1500 * the trailing '\0'. If @size is <= 0 the function returns 0.
1501 */
1502
1503int scnprintf(char *buf, size_t size, const char *fmt, ...)
1504{
1505    va_list args;
1506    int i;
1507
1508    va_start(args, fmt);
1509    i = vsnprintf(buf, size, fmt, args);
1510    va_end(args);
1511
1512    return (i >= size) ? (size - 1) : i;
1513}
1514EXPORT_SYMBOL(scnprintf);
1515
1516/**
1517 * vsprintf - Format a string and place it in a buffer
1518 * @buf: The buffer to place the result into
1519 * @fmt: The format string to use
1520 * @args: Arguments for the format string
1521 *
1522 * The function returns the number of characters written
1523 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
1524 * buffer overflows.
1525 *
1526 * Call this function if you are already dealing with a va_list.
1527 * You probably want sprintf() instead.
1528 *
1529 * See the vsnprintf() documentation for format string extensions over C99.
1530 */
1531int vsprintf(char *buf, const char *fmt, va_list args)
1532{
1533    return vsnprintf(buf, INT_MAX, fmt, args);
1534}
1535EXPORT_SYMBOL(vsprintf);
1536
1537/**
1538 * sprintf - Format a string and place it in a buffer
1539 * @buf: The buffer to place the result into
1540 * @fmt: The format string to use
1541 * @...: Arguments for the format string
1542 *
1543 * The function returns the number of characters written
1544 * into @buf. Use snprintf() or scnprintf() in order to avoid
1545 * buffer overflows.
1546 *
1547 * See the vsnprintf() documentation for format string extensions over C99.
1548 */
1549int sprintf(char *buf, const char *fmt, ...)
1550{
1551    va_list args;
1552    int i;
1553
1554    va_start(args, fmt);
1555    i = vsnprintf(buf, INT_MAX, fmt, args);
1556    va_end(args);
1557
1558    return i;
1559}
1560EXPORT_SYMBOL(sprintf);
1561
1562#ifdef CONFIG_BINARY_PRINTF
1563/*
1564 * bprintf service:
1565 * vbin_printf() - VA arguments to binary data
1566 * bstr_printf() - Binary data to text string
1567 */
1568
1569/**
1570 * vbin_printf - Parse a format string and place args' binary value in a buffer
1571 * @bin_buf: The buffer to place args' binary value
1572 * @size: The size of the buffer(by words(32bits), not characters)
1573 * @fmt: The format string to use
1574 * @args: Arguments for the format string
1575 *
1576 * The format follows C99 vsnprintf, except %n is ignored, and its argument
1577 * is skiped.
1578 *
1579 * The return value is the number of words(32bits) which would be generated for
1580 * the given input.
1581 *
1582 * NOTE:
1583 * If the return value is greater than @size, the resulting bin_buf is NOT
1584 * valid for bstr_printf().
1585 */
1586int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
1587{
1588    struct printf_spec spec = {0};
1589    char *str, *end;
1590
1591    str = (char *)bin_buf;
1592    end = (char *)(bin_buf + size);
1593
1594#define save_arg(type) \
1595do { \
1596    if (sizeof(type) == 8) { \
1597        unsigned long long value; \
1598        str = PTR_ALIGN(str, sizeof(u32)); \
1599        value = va_arg(args, unsigned long long); \
1600        if (str + sizeof(type) <= end) { \
1601            *(u32 *)str = *(u32 *)&value; \
1602            *(u32 *)(str + 4) = *((u32 *)&value + 1); \
1603        } \
1604    } else { \
1605        unsigned long value; \
1606        str = PTR_ALIGN(str, sizeof(type)); \
1607        value = va_arg(args, int); \
1608        if (str + sizeof(type) <= end) \
1609            *(typeof(type) *)str = (type)value; \
1610    } \
1611    str += sizeof(type); \
1612} while (0)
1613
1614    while (*fmt) {
1615        int read = format_decode(fmt, &spec);
1616
1617        fmt += read;
1618
1619        switch (spec.type) {
1620        case FORMAT_TYPE_NONE:
1621        case FORMAT_TYPE_INVALID:
1622        case FORMAT_TYPE_PERCENT_CHAR:
1623            break;
1624
1625        case FORMAT_TYPE_WIDTH:
1626        case FORMAT_TYPE_PRECISION:
1627            save_arg(int);
1628            break;
1629
1630        case FORMAT_TYPE_CHAR:
1631            save_arg(char);
1632            break;
1633
1634        case FORMAT_TYPE_STR: {
1635            const char *save_str = va_arg(args, char *);
1636            size_t len;
1637
1638            if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
1639                    || (unsigned long)save_str < PAGE_SIZE)
1640                save_str = "(null)";
1641            len = strlen(save_str) + 1;
1642            if (str + len < end)
1643                memcpy(str, save_str, len);
1644            str += len;
1645            break;
1646        }
1647
1648        case FORMAT_TYPE_PTR:
1649            save_arg(void *);
1650            /* skip all alphanumeric pointer suffixes */
1651            while (isalnum(*fmt))
1652                fmt++;
1653            break;
1654
1655        case FORMAT_TYPE_NRCHARS: {
1656            /* skip %n 's argument */
1657            u8 qualifier = spec.qualifier;
1658            void *skip_arg;
1659            if (qualifier == 'l')
1660                skip_arg = va_arg(args, long *);
1661            else if (TOLOWER(qualifier) == 'z')
1662                skip_arg = va_arg(args, size_t *);
1663            else
1664                skip_arg = va_arg(args, int *);
1665            break;
1666        }
1667
1668        default:
1669            switch (spec.type) {
1670
1671            case FORMAT_TYPE_LONG_LONG:
1672                save_arg(long long);
1673                break;
1674            case FORMAT_TYPE_ULONG:
1675            case FORMAT_TYPE_LONG:
1676                save_arg(unsigned long);
1677                break;
1678            case FORMAT_TYPE_SIZE_T:
1679                save_arg(size_t);
1680                break;
1681            case FORMAT_TYPE_PTRDIFF:
1682                save_arg(ptrdiff_t);
1683                break;
1684            case FORMAT_TYPE_UBYTE:
1685            case FORMAT_TYPE_BYTE:
1686                save_arg(char);
1687                break;
1688            case FORMAT_TYPE_USHORT:
1689            case FORMAT_TYPE_SHORT:
1690                save_arg(short);
1691                break;
1692            default:
1693                save_arg(int);
1694            }
1695        }
1696    }
1697
1698    return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
1699#undef save_arg
1700}
1701EXPORT_SYMBOL_GPL(vbin_printf);
1702
1703/**
1704 * bstr_printf - Format a string from binary arguments and place it in a buffer
1705 * @buf: The buffer to place the result into
1706 * @size: The size of the buffer, including the trailing null space
1707 * @fmt: The format string to use
1708 * @bin_buf: Binary arguments for the format string
1709 *
1710 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
1711 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
1712 * a binary buffer that generated by vbin_printf.
1713 *
1714 * The format follows C99 vsnprintf, but has some extensions:
1715 * see vsnprintf comment for details.
1716 *
1717 * The return value is the number of characters which would
1718 * be generated for the given input, excluding the trailing
1719 * '\0', as per ISO C99. If you want to have the exact
1720 * number of characters written into @buf as return value
1721 * (not including the trailing '\0'), use vscnprintf(). If the
1722 * return is greater than or equal to @size, the resulting
1723 * string is truncated.
1724 */
1725int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
1726{
1727    struct printf_spec spec = {0};
1728    char *str, *end;
1729    const char *args = (const char *)bin_buf;
1730
1731    if (WARN_ON_ONCE((int) size < 0))
1732        return 0;
1733
1734    str = buf;
1735    end = buf + size;
1736
1737#define get_arg(type) \
1738({ \
1739    typeof(type) value; \
1740    if (sizeof(type) == 8) { \
1741        args = PTR_ALIGN(args, sizeof(u32)); \
1742        *(u32 *)&value = *(u32 *)args; \
1743        *((u32 *)&value + 1) = *(u32 *)(args + 4); \
1744    } else { \
1745        args = PTR_ALIGN(args, sizeof(type)); \
1746        value = *(typeof(type) *)args; \
1747    } \
1748    args += sizeof(type); \
1749    value; \
1750})
1751
1752    /* Make sure end is always >= buf */
1753    if (end < buf) {
1754        end = ((void *)-1);
1755        size = end - buf;
1756    }
1757
1758    while (*fmt) {
1759        const char *old_fmt = fmt;
1760        int read = format_decode(fmt, &spec);
1761
1762        fmt += read;
1763
1764        switch (spec.type) {
1765        case FORMAT_TYPE_NONE: {
1766            int copy = read;
1767            if (str < end) {
1768                if (copy > end - str)
1769                    copy = end - str;
1770                memcpy(str, old_fmt, copy);
1771            }
1772            str += read;
1773            break;
1774        }
1775
1776        case FORMAT_TYPE_WIDTH:
1777            spec.field_width = get_arg(int);
1778            break;
1779
1780        case FORMAT_TYPE_PRECISION:
1781            spec.precision = get_arg(int);
1782            break;
1783
1784        case FORMAT_TYPE_CHAR: {
1785            char c;
1786
1787            if (!(spec.flags & LEFT)) {
1788                while (--spec.field_width > 0) {
1789                    if (str < end)
1790                        *str = ' ';
1791                    ++str;
1792                }
1793            }
1794            c = (unsigned char) get_arg(char);
1795            if (str < end)
1796                *str = c;
1797            ++str;
1798            while (--spec.field_width > 0) {
1799                if (str < end)
1800                    *str = ' ';
1801                ++str;
1802            }
1803            break;
1804        }
1805
1806        case FORMAT_TYPE_STR: {
1807            const char *str_arg = args;
1808            args += strlen(str_arg) + 1;
1809            str = string(str, end, (char *)str_arg, spec);
1810            break;
1811        }
1812
1813        case FORMAT_TYPE_PTR:
1814            str = pointer(fmt+1, str, end, get_arg(void *), spec);
1815            while (isalnum(*fmt))
1816                fmt++;
1817            break;
1818
1819        case FORMAT_TYPE_PERCENT_CHAR:
1820        case FORMAT_TYPE_INVALID:
1821            if (str < end)
1822                *str = '%';
1823            ++str;
1824            break;
1825
1826        case FORMAT_TYPE_NRCHARS:
1827            /* skip */
1828            break;
1829
1830        default: {
1831            unsigned long long num;
1832
1833            switch (spec.type) {
1834
1835            case FORMAT_TYPE_LONG_LONG:
1836                num = get_arg(long long);
1837                break;
1838            case FORMAT_TYPE_ULONG:
1839            case FORMAT_TYPE_LONG:
1840                num = get_arg(unsigned long);
1841                break;
1842            case FORMAT_TYPE_SIZE_T:
1843                num = get_arg(size_t);
1844                break;
1845            case FORMAT_TYPE_PTRDIFF:
1846                num = get_arg(ptrdiff_t);
1847                break;
1848            case FORMAT_TYPE_UBYTE:
1849                num = get_arg(unsigned char);
1850                break;
1851            case FORMAT_TYPE_BYTE:
1852                num = get_arg(signed char);
1853                break;
1854            case FORMAT_TYPE_USHORT:
1855                num = get_arg(unsigned short);
1856                break;
1857            case FORMAT_TYPE_SHORT:
1858                num = get_arg(short);
1859                break;
1860            case FORMAT_TYPE_UINT:
1861                num = get_arg(unsigned int);
1862                break;
1863            default:
1864                num = get_arg(int);
1865            }
1866
1867            str = number(str, end, num, spec);
1868        } /* default: */
1869        } /* switch(spec.type) */
1870    } /* while(*fmt) */
1871
1872    if (size > 0) {
1873        if (str < end)
1874            *str = '\0';
1875        else
1876            end[-1] = '\0';
1877    }
1878
1879#undef get_arg
1880
1881    /* the trailing null byte doesn't count towards the total */
1882    return str - buf;
1883}
1884EXPORT_SYMBOL_GPL(bstr_printf);
1885
1886/**
1887 * bprintf - Parse a format string and place args' binary value in a buffer
1888 * @bin_buf: The buffer to place args' binary value
1889 * @size: The size of the buffer(by words(32bits), not characters)
1890 * @fmt: The format string to use
1891 * @...: Arguments for the format string
1892 *
1893 * The function returns the number of words(u32) written
1894 * into @bin_buf.
1895 */
1896int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
1897{
1898    va_list args;
1899    int ret;
1900
1901    va_start(args, fmt);
1902    ret = vbin_printf(bin_buf, size, fmt, args);
1903    va_end(args);
1904
1905    return ret;
1906}
1907EXPORT_SYMBOL_GPL(bprintf);
1908
1909#endif /* CONFIG_BINARY_PRINTF */
1910
1911/**
1912 * vsscanf - Unformat a buffer into a list of arguments
1913 * @buf: input buffer
1914 * @fmt: format of buffer
1915 * @args: arguments
1916 */
1917int vsscanf(const char *buf, const char *fmt, va_list args)
1918{
1919    const char *str = buf;
1920    char *next;
1921    char digit;
1922    int num = 0;
1923    u8 qualifier;
1924    u8 base;
1925    s16 field_width;
1926    bool is_sign;
1927
1928    while (*fmt && *str) {
1929        /* skip any white space in format */
1930        /* white space in format matchs any amount of
1931         * white space, including none, in the input.
1932         */
1933        if (isspace(*fmt)) {
1934            fmt = skip_spaces(++fmt);
1935            str = skip_spaces(str);
1936        }
1937
1938        /* anything that is not a conversion must match exactly */
1939        if (*fmt != '%' && *fmt) {
1940            if (*fmt++ != *str++)
1941                break;
1942            continue;
1943        }
1944
1945        if (!*fmt)
1946            break;
1947        ++fmt;
1948
1949        /* skip this conversion.
1950         * advance both strings to next white space
1951         */
1952        if (*fmt == '*') {
1953            while (!isspace(*fmt) && *fmt != '%' && *fmt)
1954                fmt++;
1955            while (!isspace(*str) && *str)
1956                str++;
1957            continue;
1958        }
1959
1960        /* get field width */
1961        field_width = -1;
1962        if (isdigit(*fmt))
1963            field_width = skip_atoi(&fmt);
1964
1965        /* get conversion qualifier */
1966        qualifier = -1;
1967        if (*fmt == 'h' || TOLOWER(*fmt) == 'l' ||
1968            TOLOWER(*fmt) == 'z') {
1969            qualifier = *fmt++;
1970            if (unlikely(qualifier == *fmt)) {
1971                if (qualifier == 'h') {
1972                    qualifier = 'H';
1973                    fmt++;
1974                } else if (qualifier == 'l') {
1975                    qualifier = 'L';
1976                    fmt++;
1977                }
1978            }
1979        }
1980
1981        if (!*fmt || !*str)
1982            break;
1983
1984        base = 10;
1985        is_sign = 0;
1986
1987        switch (*fmt++) {
1988        case 'c':
1989        {
1990            char *s = (char *)va_arg(args, char*);
1991            if (field_width == -1)
1992                field_width = 1;
1993            do {
1994                *s++ = *str++;
1995            } while (--field_width > 0 && *str);
1996            num++;
1997        }
1998        continue;
1999        case 's':
2000        {
2001            char *s = (char *)va_arg(args, char *);
2002            if (field_width == -1)
2003                field_width = SHRT_MAX;
2004            /* first, skip leading white space in buffer */
2005            str = skip_spaces(str);
2006
2007            /* now copy until next white space */
2008            while (*str && !isspace(*str) && field_width--)
2009                *s++ = *str++;
2010            *s = '\0';
2011            num++;
2012        }
2013        continue;
2014        case 'n':
2015            /* return number of characters read so far */
2016        {
2017            int *i = (int *)va_arg(args, int*);
2018            *i = str - buf;
2019        }
2020        continue;
2021        case 'o':
2022            base = 8;
2023            break;
2024        case 'x':
2025        case 'X':
2026            base = 16;
2027            break;
2028        case 'i':
2029            base = 0;
2030        case 'd':
2031            is_sign = 1;
2032        case 'u':
2033            break;
2034        case '%':
2035            /* looking for '%' in str */
2036            if (*str++ != '%')
2037                return num;
2038            continue;
2039        default:
2040            /* invalid format; stop here */
2041            return num;
2042        }
2043
2044        /* have some sort of integer conversion.
2045         * first, skip white space in buffer.
2046         */
2047        str = skip_spaces(str);
2048
2049        digit = *str;
2050        if (is_sign && digit == '-')
2051            digit = *(str + 1);
2052
2053        if (!digit
2054            || (base == 16 && !isxdigit(digit))
2055            || (base == 10 && !isdigit(digit))
2056            || (base == 8 && (!isdigit(digit) || digit > '7'))
2057            || (base == 0 && !isdigit(digit)))
2058            break;
2059
2060        switch (qualifier) {
2061        case 'H': /* that's 'hh' in format */
2062            if (is_sign) {
2063                signed char *s = (signed char *)va_arg(args, signed char *);
2064                *s = (signed char)simple_strtol(str, &next, base);
2065            } else {
2066                unsigned char *s = (unsigned char *)va_arg(args, unsigned char *);
2067                *s = (unsigned char)simple_strtoul(str, &next, base);
2068            }
2069            break;
2070        case 'h':
2071            if (is_sign) {
2072                short *s = (short *)va_arg(args, short *);
2073                *s = (short)simple_strtol(str, &next, base);
2074            } else {
2075                unsigned short *s = (unsigned short *)va_arg(args, unsigned short *);
2076                *s = (unsigned short)simple_strtoul(str, &next, base);
2077            }
2078            break;
2079        case 'l':
2080            if (is_sign) {
2081                long *l = (long *)va_arg(args, long *);
2082                *l = simple_strtol(str, &next, base);
2083            } else {
2084                unsigned long *l = (unsigned long *)va_arg(args, unsigned long *);
2085                *l = simple_strtoul(str, &next, base);
2086            }
2087            break;
2088        case 'L':
2089            if (is_sign) {
2090                long long *l = (long long *)va_arg(args, long long *);
2091                *l = simple_strtoll(str, &next, base);
2092            } else {
2093                unsigned long long *l = (unsigned long long *)va_arg(args, unsigned long long *);
2094                *l = simple_strtoull(str, &next, base);
2095            }
2096            break;
2097        case 'Z':
2098        case 'z':
2099        {
2100            size_t *s = (size_t *)va_arg(args, size_t *);
2101            *s = (size_t)simple_strtoul(str, &next, base);
2102        }
2103        break;
2104        default:
2105            if (is_sign) {
2106                int *i = (int *)va_arg(args, int *);
2107                *i = (int)simple_strtol(str, &next, base);
2108            } else {
2109                unsigned int *i = (unsigned int *)va_arg(args, unsigned int*);
2110                *i = (unsigned int)simple_strtoul(str, &next, base);
2111            }
2112            break;
2113        }
2114        num++;
2115
2116        if (!next)
2117            break;
2118        str = next;
2119    }
2120
2121    /*
2122     * Now we've come all the way through so either the input string or the
2123     * format ended. In the former case, there can be a %n at the current
2124     * position in the format that needs to be filled.
2125     */
2126    if (*fmt == '%' && *(fmt + 1) == 'n') {
2127        int *p = (int *)va_arg(args, int *);
2128        *p = str - buf;
2129    }
2130
2131    return num;
2132}
2133EXPORT_SYMBOL(vsscanf);
2134
2135/**
2136 * sscanf - Unformat a buffer into a list of arguments
2137 * @buf: input buffer
2138 * @fmt: formatting of buffer
2139 * @...: resulting arguments
2140 */
2141int sscanf(const char *buf, const char *fmt, ...)
2142{
2143    va_list args;
2144    int i;
2145
2146    va_start(args, fmt);
2147    i = vsscanf(buf, fmt, args);
2148    va_end(args);
2149
2150    return i;
2151}
2152EXPORT_SYMBOL(sscanf);
2153

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