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0001 /*
0002  *  linux/lib/vsprintf.c
0003  *
0004  *  Copyright (C) 1991, 1992  Linus Torvalds
0005  */
0006 
0007 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
0008 /*
0009  * Wirzenius wrote this portably, Torvalds fucked it up :-)
0010  */
0011 
0012 /*
0013  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
0014  * - changed to provide snprintf and vsnprintf functions
0015  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
0016  * - scnprintf and vscnprintf
0017  */
0018 
0019 #include <stdarg.h>
0020 #include <linux/clk.h>
0021 #include <linux/clk-provider.h>
0022 #include <linux/module.h>   /* for KSYM_SYMBOL_LEN */
0023 #include <linux/types.h>
0024 #include <linux/string.h>
0025 #include <linux/ctype.h>
0026 #include <linux/kernel.h>
0027 #include <linux/kallsyms.h>
0028 #include <linux/math64.h>
0029 #include <linux/uaccess.h>
0030 #include <linux/ioport.h>
0031 #include <linux/dcache.h>
0032 #include <linux/cred.h>
0033 #include <linux/uuid.h>
0034 #include <net/addrconf.h>
0035 #ifdef CONFIG_BLOCK
0036 #include <linux/blkdev.h>
0037 #endif
0038 
0039 #include "../mm/internal.h" /* For the trace_print_flags arrays */
0040 
0041 #include <asm/page.h>       /* for PAGE_SIZE */
0042 #include <asm/sections.h>   /* for dereference_function_descriptor() */
0043 #include <asm/byteorder.h>  /* cpu_to_le16 */
0044 
0045 #include <linux/string_helpers.h>
0046 #include "kstrtox.h"
0047 
0048 /**
0049  * simple_strtoull - convert a string to an unsigned long long
0050  * @cp: The start of the string
0051  * @endp: A pointer to the end of the parsed string will be placed here
0052  * @base: The number base to use
0053  *
0054  * This function is obsolete. Please use kstrtoull instead.
0055  */
0056 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
0057 {
0058     unsigned long long result;
0059     unsigned int rv;
0060 
0061     cp = _parse_integer_fixup_radix(cp, &base);
0062     rv = _parse_integer(cp, base, &result);
0063     /* FIXME */
0064     cp += (rv & ~KSTRTOX_OVERFLOW);
0065 
0066     if (endp)
0067         *endp = (char *)cp;
0068 
0069     return result;
0070 }
0071 EXPORT_SYMBOL(simple_strtoull);
0072 
0073 /**
0074  * simple_strtoul - convert a string to an unsigned long
0075  * @cp: The start of the string
0076  * @endp: A pointer to the end of the parsed string will be placed here
0077  * @base: The number base to use
0078  *
0079  * This function is obsolete. Please use kstrtoul instead.
0080  */
0081 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
0082 {
0083     return simple_strtoull(cp, endp, base);
0084 }
0085 EXPORT_SYMBOL(simple_strtoul);
0086 
0087 /**
0088  * simple_strtol - convert a string to a signed long
0089  * @cp: The start of the string
0090  * @endp: A pointer to the end of the parsed string will be placed here
0091  * @base: The number base to use
0092  *
0093  * This function is obsolete. Please use kstrtol instead.
0094  */
0095 long simple_strtol(const char *cp, char **endp, unsigned int base)
0096 {
0097     if (*cp == '-')
0098         return -simple_strtoul(cp + 1, endp, base);
0099 
0100     return simple_strtoul(cp, endp, base);
0101 }
0102 EXPORT_SYMBOL(simple_strtol);
0103 
0104 /**
0105  * simple_strtoll - convert a string to a signed long long
0106  * @cp: The start of the string
0107  * @endp: A pointer to the end of the parsed string will be placed here
0108  * @base: The number base to use
0109  *
0110  * This function is obsolete. Please use kstrtoll instead.
0111  */
0112 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
0113 {
0114     if (*cp == '-')
0115         return -simple_strtoull(cp + 1, endp, base);
0116 
0117     return simple_strtoull(cp, endp, base);
0118 }
0119 EXPORT_SYMBOL(simple_strtoll);
0120 
0121 static noinline_for_stack
0122 int skip_atoi(const char **s)
0123 {
0124     int i = 0;
0125 
0126     do {
0127         i = i*10 + *((*s)++) - '0';
0128     } while (isdigit(**s));
0129 
0130     return i;
0131 }
0132 
0133 /*
0134  * Decimal conversion is by far the most typical, and is used for
0135  * /proc and /sys data. This directly impacts e.g. top performance
0136  * with many processes running. We optimize it for speed by emitting
0137  * two characters at a time, using a 200 byte lookup table. This
0138  * roughly halves the number of multiplications compared to computing
0139  * the digits one at a time. Implementation strongly inspired by the
0140  * previous version, which in turn used ideas described at
0141  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
0142  * from the author, Douglas W. Jones).
0143  *
0144  * It turns out there is precisely one 26 bit fixed-point
0145  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
0146  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
0147  * range happens to be somewhat larger (x <= 1073741898), but that's
0148  * irrelevant for our purpose.
0149  *
0150  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
0151  * need a 32x32->64 bit multiply, so we simply use the same constant.
0152  *
0153  * For dividing a number in the range [100, 10^4-1] by 100, there are
0154  * several options. The simplest is (x * 0x147b) >> 19, which is valid
0155  * for all x <= 43698.
0156  */
0157 
0158 static const u16 decpair[100] = {
0159 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
0160     _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
0161     _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
0162     _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
0163     _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
0164     _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
0165     _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
0166     _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
0167     _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
0168     _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
0169     _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
0170 #undef _
0171 };
0172 
0173 /*
0174  * This will print a single '0' even if r == 0, since we would
0175  * immediately jump to out_r where two 0s would be written but only
0176  * one of them accounted for in buf. This is needed by ip4_string
0177  * below. All other callers pass a non-zero value of r.
0178 */
0179 static noinline_for_stack
0180 char *put_dec_trunc8(char *buf, unsigned r)
0181 {
0182     unsigned q;
0183 
0184     /* 1 <= r < 10^8 */
0185     if (r < 100)
0186         goto out_r;
0187 
0188     /* 100 <= r < 10^8 */
0189     q = (r * (u64)0x28f5c29) >> 32;
0190     *((u16 *)buf) = decpair[r - 100*q];
0191     buf += 2;
0192 
0193     /* 1 <= q < 10^6 */
0194     if (q < 100)
0195         goto out_q;
0196 
0197     /*  100 <= q < 10^6 */
0198     r = (q * (u64)0x28f5c29) >> 32;
0199     *((u16 *)buf) = decpair[q - 100*r];
0200     buf += 2;
0201 
0202     /* 1 <= r < 10^4 */
0203     if (r < 100)
0204         goto out_r;
0205 
0206     /* 100 <= r < 10^4 */
0207     q = (r * 0x147b) >> 19;
0208     *((u16 *)buf) = decpair[r - 100*q];
0209     buf += 2;
0210 out_q:
0211     /* 1 <= q < 100 */
0212     r = q;
0213 out_r:
0214     /* 1 <= r < 100 */
0215     *((u16 *)buf) = decpair[r];
0216     buf += r < 10 ? 1 : 2;
0217     return buf;
0218 }
0219 
0220 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
0221 static noinline_for_stack
0222 char *put_dec_full8(char *buf, unsigned r)
0223 {
0224     unsigned q;
0225 
0226     /* 0 <= r < 10^8 */
0227     q = (r * (u64)0x28f5c29) >> 32;
0228     *((u16 *)buf) = decpair[r - 100*q];
0229     buf += 2;
0230 
0231     /* 0 <= q < 10^6 */
0232     r = (q * (u64)0x28f5c29) >> 32;
0233     *((u16 *)buf) = decpair[q - 100*r];
0234     buf += 2;
0235 
0236     /* 0 <= r < 10^4 */
0237     q = (r * 0x147b) >> 19;
0238     *((u16 *)buf) = decpair[r - 100*q];
0239     buf += 2;
0240 
0241     /* 0 <= q < 100 */
0242     *((u16 *)buf) = decpair[q];
0243     buf += 2;
0244     return buf;
0245 }
0246 
0247 static noinline_for_stack
0248 char *put_dec(char *buf, unsigned long long n)
0249 {
0250     if (n >= 100*1000*1000)
0251         buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
0252     /* 1 <= n <= 1.6e11 */
0253     if (n >= 100*1000*1000)
0254         buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
0255     /* 1 <= n < 1e8 */
0256     return put_dec_trunc8(buf, n);
0257 }
0258 
0259 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
0260 
0261 static void
0262 put_dec_full4(char *buf, unsigned r)
0263 {
0264     unsigned q;
0265 
0266     /* 0 <= r < 10^4 */
0267     q = (r * 0x147b) >> 19;
0268     *((u16 *)buf) = decpair[r - 100*q];
0269     buf += 2;
0270     /* 0 <= q < 100 */
0271     *((u16 *)buf) = decpair[q];
0272 }
0273 
0274 /*
0275  * Call put_dec_full4 on x % 10000, return x / 10000.
0276  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
0277  * holds for all x < 1,128,869,999.  The largest value this
0278  * helper will ever be asked to convert is 1,125,520,955.
0279  * (second call in the put_dec code, assuming n is all-ones).
0280  */
0281 static noinline_for_stack
0282 unsigned put_dec_helper4(char *buf, unsigned x)
0283 {
0284         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
0285 
0286         put_dec_full4(buf, x - q * 10000);
0287         return q;
0288 }
0289 
0290 /* Based on code by Douglas W. Jones found at
0291  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
0292  * (with permission from the author).
0293  * Performs no 64-bit division and hence should be fast on 32-bit machines.
0294  */
0295 static
0296 char *put_dec(char *buf, unsigned long long n)
0297 {
0298     uint32_t d3, d2, d1, q, h;
0299 
0300     if (n < 100*1000*1000)
0301         return put_dec_trunc8(buf, n);
0302 
0303     d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
0304     h   = (n >> 32);
0305     d2  = (h      ) & 0xffff;
0306     d3  = (h >> 16); /* implicit "& 0xffff" */
0307 
0308     /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
0309          = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
0310     q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
0311     q = put_dec_helper4(buf, q);
0312 
0313     q += 7671 * d3 + 9496 * d2 + 6 * d1;
0314     q = put_dec_helper4(buf+4, q);
0315 
0316     q += 4749 * d3 + 42 * d2;
0317     q = put_dec_helper4(buf+8, q);
0318 
0319     q += 281 * d3;
0320     buf += 12;
0321     if (q)
0322         buf = put_dec_trunc8(buf, q);
0323     else while (buf[-1] == '0')
0324         --buf;
0325 
0326     return buf;
0327 }
0328 
0329 #endif
0330 
0331 /*
0332  * Convert passed number to decimal string.
0333  * Returns the length of string.  On buffer overflow, returns 0.
0334  *
0335  * If speed is not important, use snprintf(). It's easy to read the code.
0336  */
0337 int num_to_str(char *buf, int size, unsigned long long num)
0338 {
0339     /* put_dec requires 2-byte alignment of the buffer. */
0340     char tmp[sizeof(num) * 3] __aligned(2);
0341     int idx, len;
0342 
0343     /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
0344     if (num <= 9) {
0345         tmp[0] = '0' + num;
0346         len = 1;
0347     } else {
0348         len = put_dec(tmp, num) - tmp;
0349     }
0350 
0351     if (len > size)
0352         return 0;
0353     for (idx = 0; idx < len; ++idx)
0354         buf[idx] = tmp[len - idx - 1];
0355     return len;
0356 }
0357 
0358 #define SIGN    1       /* unsigned/signed, must be 1 */
0359 #define LEFT    2       /* left justified */
0360 #define PLUS    4       /* show plus */
0361 #define SPACE   8       /* space if plus */
0362 #define ZEROPAD 16      /* pad with zero, must be 16 == '0' - ' ' */
0363 #define SMALL   32      /* use lowercase in hex (must be 32 == 0x20) */
0364 #define SPECIAL 64      /* prefix hex with "0x", octal with "0" */
0365 
0366 enum format_type {
0367     FORMAT_TYPE_NONE, /* Just a string part */
0368     FORMAT_TYPE_WIDTH,
0369     FORMAT_TYPE_PRECISION,
0370     FORMAT_TYPE_CHAR,
0371     FORMAT_TYPE_STR,
0372     FORMAT_TYPE_PTR,
0373     FORMAT_TYPE_PERCENT_CHAR,
0374     FORMAT_TYPE_INVALID,
0375     FORMAT_TYPE_LONG_LONG,
0376     FORMAT_TYPE_ULONG,
0377     FORMAT_TYPE_LONG,
0378     FORMAT_TYPE_UBYTE,
0379     FORMAT_TYPE_BYTE,
0380     FORMAT_TYPE_USHORT,
0381     FORMAT_TYPE_SHORT,
0382     FORMAT_TYPE_UINT,
0383     FORMAT_TYPE_INT,
0384     FORMAT_TYPE_SIZE_T,
0385     FORMAT_TYPE_PTRDIFF
0386 };
0387 
0388 struct printf_spec {
0389     unsigned int    type:8;     /* format_type enum */
0390     signed int  field_width:24; /* width of output field */
0391     unsigned int    flags:8;    /* flags to number() */
0392     unsigned int    base:8;     /* number base, 8, 10 or 16 only */
0393     signed int  precision:16;   /* # of digits/chars */
0394 } __packed;
0395 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
0396 #define PRECISION_MAX ((1 << 15) - 1)
0397 
0398 static noinline_for_stack
0399 char *number(char *buf, char *end, unsigned long long num,
0400          struct printf_spec spec)
0401 {
0402     /* put_dec requires 2-byte alignment of the buffer. */
0403     char tmp[3 * sizeof(num)] __aligned(2);
0404     char sign;
0405     char locase;
0406     int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
0407     int i;
0408     bool is_zero = num == 0LL;
0409     int field_width = spec.field_width;
0410     int precision = spec.precision;
0411 
0412     BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
0413 
0414     /* locase = 0 or 0x20. ORing digits or letters with 'locase'
0415      * produces same digits or (maybe lowercased) letters */
0416     locase = (spec.flags & SMALL);
0417     if (spec.flags & LEFT)
0418         spec.flags &= ~ZEROPAD;
0419     sign = 0;
0420     if (spec.flags & SIGN) {
0421         if ((signed long long)num < 0) {
0422             sign = '-';
0423             num = -(signed long long)num;
0424             field_width--;
0425         } else if (spec.flags & PLUS) {
0426             sign = '+';
0427             field_width--;
0428         } else if (spec.flags & SPACE) {
0429             sign = ' ';
0430             field_width--;
0431         }
0432     }
0433     if (need_pfx) {
0434         if (spec.base == 16)
0435             field_width -= 2;
0436         else if (!is_zero)
0437             field_width--;
0438     }
0439 
0440     /* generate full string in tmp[], in reverse order */
0441     i = 0;
0442     if (num < spec.base)
0443         tmp[i++] = hex_asc_upper[num] | locase;
0444     else if (spec.base != 10) { /* 8 or 16 */
0445         int mask = spec.base - 1;
0446         int shift = 3;
0447 
0448         if (spec.base == 16)
0449             shift = 4;
0450         do {
0451             tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
0452             num >>= shift;
0453         } while (num);
0454     } else { /* base 10 */
0455         i = put_dec(tmp, num) - tmp;
0456     }
0457 
0458     /* printing 100 using %2d gives "100", not "00" */
0459     if (i > precision)
0460         precision = i;
0461     /* leading space padding */
0462     field_width -= precision;
0463     if (!(spec.flags & (ZEROPAD | LEFT))) {
0464         while (--field_width >= 0) {
0465             if (buf < end)
0466                 *buf = ' ';
0467             ++buf;
0468         }
0469     }
0470     /* sign */
0471     if (sign) {
0472         if (buf < end)
0473             *buf = sign;
0474         ++buf;
0475     }
0476     /* "0x" / "0" prefix */
0477     if (need_pfx) {
0478         if (spec.base == 16 || !is_zero) {
0479             if (buf < end)
0480                 *buf = '0';
0481             ++buf;
0482         }
0483         if (spec.base == 16) {
0484             if (buf < end)
0485                 *buf = ('X' | locase);
0486             ++buf;
0487         }
0488     }
0489     /* zero or space padding */
0490     if (!(spec.flags & LEFT)) {
0491         char c = ' ' + (spec.flags & ZEROPAD);
0492         BUILD_BUG_ON(' ' + ZEROPAD != '0');
0493         while (--field_width >= 0) {
0494             if (buf < end)
0495                 *buf = c;
0496             ++buf;
0497         }
0498     }
0499     /* hmm even more zero padding? */
0500     while (i <= --precision) {
0501         if (buf < end)
0502             *buf = '0';
0503         ++buf;
0504     }
0505     /* actual digits of result */
0506     while (--i >= 0) {
0507         if (buf < end)
0508             *buf = tmp[i];
0509         ++buf;
0510     }
0511     /* trailing space padding */
0512     while (--field_width >= 0) {
0513         if (buf < end)
0514             *buf = ' ';
0515         ++buf;
0516     }
0517 
0518     return buf;
0519 }
0520 
0521 static noinline_for_stack
0522 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
0523 {
0524     struct printf_spec spec;
0525 
0526     spec.type = FORMAT_TYPE_PTR;
0527     spec.field_width = 2 + 2 * size;    /* 0x + hex */
0528     spec.flags = SPECIAL | SMALL | ZEROPAD;
0529     spec.base = 16;
0530     spec.precision = -1;
0531 
0532     return number(buf, end, num, spec);
0533 }
0534 
0535 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
0536 {
0537     size_t size;
0538     if (buf >= end) /* nowhere to put anything */
0539         return;
0540     size = end - buf;
0541     if (size <= spaces) {
0542         memset(buf, ' ', size);
0543         return;
0544     }
0545     if (len) {
0546         if (len > size - spaces)
0547             len = size - spaces;
0548         memmove(buf + spaces, buf, len);
0549     }
0550     memset(buf, ' ', spaces);
0551 }
0552 
0553 /*
0554  * Handle field width padding for a string.
0555  * @buf: current buffer position
0556  * @n: length of string
0557  * @end: end of output buffer
0558  * @spec: for field width and flags
0559  * Returns: new buffer position after padding.
0560  */
0561 static noinline_for_stack
0562 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
0563 {
0564     unsigned spaces;
0565 
0566     if (likely(n >= spec.field_width))
0567         return buf;
0568     /* we want to pad the sucker */
0569     spaces = spec.field_width - n;
0570     if (!(spec.flags & LEFT)) {
0571         move_right(buf - n, end, n, spaces);
0572         return buf + spaces;
0573     }
0574     while (spaces--) {
0575         if (buf < end)
0576             *buf = ' ';
0577         ++buf;
0578     }
0579     return buf;
0580 }
0581 
0582 static noinline_for_stack
0583 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
0584 {
0585     int len = 0;
0586     size_t lim = spec.precision;
0587 
0588     if ((unsigned long)s < PAGE_SIZE)
0589         s = "(null)";
0590 
0591     while (lim--) {
0592         char c = *s++;
0593         if (!c)
0594             break;
0595         if (buf < end)
0596             *buf = c;
0597         ++buf;
0598         ++len;
0599     }
0600     return widen_string(buf, len, end, spec);
0601 }
0602 
0603 static noinline_for_stack
0604 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
0605           const char *fmt)
0606 {
0607     const char *array[4], *s;
0608     const struct dentry *p;
0609     int depth;
0610     int i, n;
0611 
0612     switch (fmt[1]) {
0613         case '2': case '3': case '4':
0614             depth = fmt[1] - '0';
0615             break;
0616         default:
0617             depth = 1;
0618     }
0619 
0620     rcu_read_lock();
0621     for (i = 0; i < depth; i++, d = p) {
0622         p = ACCESS_ONCE(d->d_parent);
0623         array[i] = ACCESS_ONCE(d->d_name.name);
0624         if (p == d) {
0625             if (i)
0626                 array[i] = "";
0627             i++;
0628             break;
0629         }
0630     }
0631     s = array[--i];
0632     for (n = 0; n != spec.precision; n++, buf++) {
0633         char c = *s++;
0634         if (!c) {
0635             if (!i)
0636                 break;
0637             c = '/';
0638             s = array[--i];
0639         }
0640         if (buf < end)
0641             *buf = c;
0642     }
0643     rcu_read_unlock();
0644     return widen_string(buf, n, end, spec);
0645 }
0646 
0647 #ifdef CONFIG_BLOCK
0648 static noinline_for_stack
0649 char *bdev_name(char *buf, char *end, struct block_device *bdev,
0650         struct printf_spec spec, const char *fmt)
0651 {
0652     struct gendisk *hd = bdev->bd_disk;
0653     
0654     buf = string(buf, end, hd->disk_name, spec);
0655     if (bdev->bd_part->partno) {
0656         if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
0657             if (buf < end)
0658                 *buf = 'p';
0659             buf++;
0660         }
0661         buf = number(buf, end, bdev->bd_part->partno, spec);
0662     }
0663     return buf;
0664 }
0665 #endif
0666 
0667 static noinline_for_stack
0668 char *symbol_string(char *buf, char *end, void *ptr,
0669             struct printf_spec spec, const char *fmt)
0670 {
0671     unsigned long value;
0672 #ifdef CONFIG_KALLSYMS
0673     char sym[KSYM_SYMBOL_LEN];
0674 #endif
0675 
0676     if (fmt[1] == 'R')
0677         ptr = __builtin_extract_return_addr(ptr);
0678     value = (unsigned long)ptr;
0679 
0680 #ifdef CONFIG_KALLSYMS
0681     if (*fmt == 'B')
0682         sprint_backtrace(sym, value);
0683     else if (*fmt != 'f' && *fmt != 's')
0684         sprint_symbol(sym, value);
0685     else
0686         sprint_symbol_no_offset(sym, value);
0687 
0688     return string(buf, end, sym, spec);
0689 #else
0690     return special_hex_number(buf, end, value, sizeof(void *));
0691 #endif
0692 }
0693 
0694 static noinline_for_stack
0695 char *resource_string(char *buf, char *end, struct resource *res,
0696               struct printf_spec spec, const char *fmt)
0697 {
0698 #ifndef IO_RSRC_PRINTK_SIZE
0699 #define IO_RSRC_PRINTK_SIZE 6
0700 #endif
0701 
0702 #ifndef MEM_RSRC_PRINTK_SIZE
0703 #define MEM_RSRC_PRINTK_SIZE    10
0704 #endif
0705     static const struct printf_spec io_spec = {
0706         .base = 16,
0707         .field_width = IO_RSRC_PRINTK_SIZE,
0708         .precision = -1,
0709         .flags = SPECIAL | SMALL | ZEROPAD,
0710     };
0711     static const struct printf_spec mem_spec = {
0712         .base = 16,
0713         .field_width = MEM_RSRC_PRINTK_SIZE,
0714         .precision = -1,
0715         .flags = SPECIAL | SMALL | ZEROPAD,
0716     };
0717     static const struct printf_spec bus_spec = {
0718         .base = 16,
0719         .field_width = 2,
0720         .precision = -1,
0721         .flags = SMALL | ZEROPAD,
0722     };
0723     static const struct printf_spec dec_spec = {
0724         .base = 10,
0725         .precision = -1,
0726         .flags = 0,
0727     };
0728     static const struct printf_spec str_spec = {
0729         .field_width = -1,
0730         .precision = 10,
0731         .flags = LEFT,
0732     };
0733     static const struct printf_spec flag_spec = {
0734         .base = 16,
0735         .precision = -1,
0736         .flags = SPECIAL | SMALL,
0737     };
0738 
0739     /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
0740      * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
0741 #define RSRC_BUF_SIZE       ((2 * sizeof(resource_size_t)) + 4)
0742 #define FLAG_BUF_SIZE       (2 * sizeof(res->flags))
0743 #define DECODED_BUF_SIZE    sizeof("[mem - 64bit pref window disabled]")
0744 #define RAW_BUF_SIZE        sizeof("[mem - flags 0x]")
0745     char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
0746              2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
0747 
0748     char *p = sym, *pend = sym + sizeof(sym);
0749     int decode = (fmt[0] == 'R') ? 1 : 0;
0750     const struct printf_spec *specp;
0751 
0752     *p++ = '[';
0753     if (res->flags & IORESOURCE_IO) {
0754         p = string(p, pend, "io  ", str_spec);
0755         specp = &io_spec;
0756     } else if (res->flags & IORESOURCE_MEM) {
0757         p = string(p, pend, "mem ", str_spec);
0758         specp = &mem_spec;
0759     } else if (res->flags & IORESOURCE_IRQ) {
0760         p = string(p, pend, "irq ", str_spec);
0761         specp = &dec_spec;
0762     } else if (res->flags & IORESOURCE_DMA) {
0763         p = string(p, pend, "dma ", str_spec);
0764         specp = &dec_spec;
0765     } else if (res->flags & IORESOURCE_BUS) {
0766         p = string(p, pend, "bus ", str_spec);
0767         specp = &bus_spec;
0768     } else {
0769         p = string(p, pend, "??? ", str_spec);
0770         specp = &mem_spec;
0771         decode = 0;
0772     }
0773     if (decode && res->flags & IORESOURCE_UNSET) {
0774         p = string(p, pend, "size ", str_spec);
0775         p = number(p, pend, resource_size(res), *specp);
0776     } else {
0777         p = number(p, pend, res->start, *specp);
0778         if (res->start != res->end) {
0779             *p++ = '-';
0780             p = number(p, pend, res->end, *specp);
0781         }
0782     }
0783     if (decode) {
0784         if (res->flags & IORESOURCE_MEM_64)
0785             p = string(p, pend, " 64bit", str_spec);
0786         if (res->flags & IORESOURCE_PREFETCH)
0787             p = string(p, pend, " pref", str_spec);
0788         if (res->flags & IORESOURCE_WINDOW)
0789             p = string(p, pend, " window", str_spec);
0790         if (res->flags & IORESOURCE_DISABLED)
0791             p = string(p, pend, " disabled", str_spec);
0792     } else {
0793         p = string(p, pend, " flags ", str_spec);
0794         p = number(p, pend, res->flags, flag_spec);
0795     }
0796     *p++ = ']';
0797     *p = '\0';
0798 
0799     return string(buf, end, sym, spec);
0800 }
0801 
0802 static noinline_for_stack
0803 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
0804          const char *fmt)
0805 {
0806     int i, len = 1;     /* if we pass '%ph[CDN]', field width remains
0807                    negative value, fallback to the default */
0808     char separator;
0809 
0810     if (spec.field_width == 0)
0811         /* nothing to print */
0812         return buf;
0813 
0814     if (ZERO_OR_NULL_PTR(addr))
0815         /* NULL pointer */
0816         return string(buf, end, NULL, spec);
0817 
0818     switch (fmt[1]) {
0819     case 'C':
0820         separator = ':';
0821         break;
0822     case 'D':
0823         separator = '-';
0824         break;
0825     case 'N':
0826         separator = 0;
0827         break;
0828     default:
0829         separator = ' ';
0830         break;
0831     }
0832 
0833     if (spec.field_width > 0)
0834         len = min_t(int, spec.field_width, 64);
0835 
0836     for (i = 0; i < len; ++i) {
0837         if (buf < end)
0838             *buf = hex_asc_hi(addr[i]);
0839         ++buf;
0840         if (buf < end)
0841             *buf = hex_asc_lo(addr[i]);
0842         ++buf;
0843 
0844         if (separator && i != len - 1) {
0845             if (buf < end)
0846                 *buf = separator;
0847             ++buf;
0848         }
0849     }
0850 
0851     return buf;
0852 }
0853 
0854 static noinline_for_stack
0855 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
0856             struct printf_spec spec, const char *fmt)
0857 {
0858     const int CHUNKSZ = 32;
0859     int nr_bits = max_t(int, spec.field_width, 0);
0860     int i, chunksz;
0861     bool first = true;
0862 
0863     /* reused to print numbers */
0864     spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
0865 
0866     chunksz = nr_bits & (CHUNKSZ - 1);
0867     if (chunksz == 0)
0868         chunksz = CHUNKSZ;
0869 
0870     i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
0871     for (; i >= 0; i -= CHUNKSZ) {
0872         u32 chunkmask, val;
0873         int word, bit;
0874 
0875         chunkmask = ((1ULL << chunksz) - 1);
0876         word = i / BITS_PER_LONG;
0877         bit = i % BITS_PER_LONG;
0878         val = (bitmap[word] >> bit) & chunkmask;
0879 
0880         if (!first) {
0881             if (buf < end)
0882                 *buf = ',';
0883             buf++;
0884         }
0885         first = false;
0886 
0887         spec.field_width = DIV_ROUND_UP(chunksz, 4);
0888         buf = number(buf, end, val, spec);
0889 
0890         chunksz = CHUNKSZ;
0891     }
0892     return buf;
0893 }
0894 
0895 static noinline_for_stack
0896 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
0897              struct printf_spec spec, const char *fmt)
0898 {
0899     int nr_bits = max_t(int, spec.field_width, 0);
0900     /* current bit is 'cur', most recently seen range is [rbot, rtop] */
0901     int cur, rbot, rtop;
0902     bool first = true;
0903 
0904     /* reused to print numbers */
0905     spec = (struct printf_spec){ .base = 10 };
0906 
0907     rbot = cur = find_first_bit(bitmap, nr_bits);
0908     while (cur < nr_bits) {
0909         rtop = cur;
0910         cur = find_next_bit(bitmap, nr_bits, cur + 1);
0911         if (cur < nr_bits && cur <= rtop + 1)
0912             continue;
0913 
0914         if (!first) {
0915             if (buf < end)
0916                 *buf = ',';
0917             buf++;
0918         }
0919         first = false;
0920 
0921         buf = number(buf, end, rbot, spec);
0922         if (rbot < rtop) {
0923             if (buf < end)
0924                 *buf = '-';
0925             buf++;
0926 
0927             buf = number(buf, end, rtop, spec);
0928         }
0929 
0930         rbot = cur;
0931     }
0932     return buf;
0933 }
0934 
0935 static noinline_for_stack
0936 char *mac_address_string(char *buf, char *end, u8 *addr,
0937              struct printf_spec spec, const char *fmt)
0938 {
0939     char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
0940     char *p = mac_addr;
0941     int i;
0942     char separator;
0943     bool reversed = false;
0944 
0945     switch (fmt[1]) {
0946     case 'F':
0947         separator = '-';
0948         break;
0949 
0950     case 'R':
0951         reversed = true;
0952         /* fall through */
0953 
0954     default:
0955         separator = ':';
0956         break;
0957     }
0958 
0959     for (i = 0; i < 6; i++) {
0960         if (reversed)
0961             p = hex_byte_pack(p, addr[5 - i]);
0962         else
0963             p = hex_byte_pack(p, addr[i]);
0964 
0965         if (fmt[0] == 'M' && i != 5)
0966             *p++ = separator;
0967     }
0968     *p = '\0';
0969 
0970     return string(buf, end, mac_addr, spec);
0971 }
0972 
0973 static noinline_for_stack
0974 char *ip4_string(char *p, const u8 *addr, const char *fmt)
0975 {
0976     int i;
0977     bool leading_zeros = (fmt[0] == 'i');
0978     int index;
0979     int step;
0980 
0981     switch (fmt[2]) {
0982     case 'h':
0983 #ifdef __BIG_ENDIAN
0984         index = 0;
0985         step = 1;
0986 #else
0987         index = 3;
0988         step = -1;
0989 #endif
0990         break;
0991     case 'l':
0992         index = 3;
0993         step = -1;
0994         break;
0995     case 'n':
0996     case 'b':
0997     default:
0998         index = 0;
0999         step = 1;
1000         break;
1001     }
1002     for (i = 0; i < 4; i++) {
1003         char temp[4] __aligned(2);  /* hold each IP quad in reverse order */
1004         int digits = put_dec_trunc8(temp, addr[index]) - temp;
1005         if (leading_zeros) {
1006             if (digits < 3)
1007                 *p++ = '0';
1008             if (digits < 2)
1009                 *p++ = '0';
1010         }
1011         /* reverse the digits in the quad */
1012         while (digits--)
1013             *p++ = temp[digits];
1014         if (i < 3)
1015             *p++ = '.';
1016         index += step;
1017     }
1018     *p = '\0';
1019 
1020     return p;
1021 }
1022 
1023 static noinline_for_stack
1024 char *ip6_compressed_string(char *p, const char *addr)
1025 {
1026     int i, j, range;
1027     unsigned char zerolength[8];
1028     int longest = 1;
1029     int colonpos = -1;
1030     u16 word;
1031     u8 hi, lo;
1032     bool needcolon = false;
1033     bool useIPv4;
1034     struct in6_addr in6;
1035 
1036     memcpy(&in6, addr, sizeof(struct in6_addr));
1037 
1038     useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1039 
1040     memset(zerolength, 0, sizeof(zerolength));
1041 
1042     if (useIPv4)
1043         range = 6;
1044     else
1045         range = 8;
1046 
1047     /* find position of longest 0 run */
1048     for (i = 0; i < range; i++) {
1049         for (j = i; j < range; j++) {
1050             if (in6.s6_addr16[j] != 0)
1051                 break;
1052             zerolength[i]++;
1053         }
1054     }
1055     for (i = 0; i < range; i++) {
1056         if (zerolength[i] > longest) {
1057             longest = zerolength[i];
1058             colonpos = i;
1059         }
1060     }
1061     if (longest == 1)       /* don't compress a single 0 */
1062         colonpos = -1;
1063 
1064     /* emit address */
1065     for (i = 0; i < range; i++) {
1066         if (i == colonpos) {
1067             if (needcolon || i == 0)
1068                 *p++ = ':';
1069             *p++ = ':';
1070             needcolon = false;
1071             i += longest - 1;
1072             continue;
1073         }
1074         if (needcolon) {
1075             *p++ = ':';
1076             needcolon = false;
1077         }
1078         /* hex u16 without leading 0s */
1079         word = ntohs(in6.s6_addr16[i]);
1080         hi = word >> 8;
1081         lo = word & 0xff;
1082         if (hi) {
1083             if (hi > 0x0f)
1084                 p = hex_byte_pack(p, hi);
1085             else
1086                 *p++ = hex_asc_lo(hi);
1087             p = hex_byte_pack(p, lo);
1088         }
1089         else if (lo > 0x0f)
1090             p = hex_byte_pack(p, lo);
1091         else
1092             *p++ = hex_asc_lo(lo);
1093         needcolon = true;
1094     }
1095 
1096     if (useIPv4) {
1097         if (needcolon)
1098             *p++ = ':';
1099         p = ip4_string(p, &in6.s6_addr[12], "I4");
1100     }
1101     *p = '\0';
1102 
1103     return p;
1104 }
1105 
1106 static noinline_for_stack
1107 char *ip6_string(char *p, const char *addr, const char *fmt)
1108 {
1109     int i;
1110 
1111     for (i = 0; i < 8; i++) {
1112         p = hex_byte_pack(p, *addr++);
1113         p = hex_byte_pack(p, *addr++);
1114         if (fmt[0] == 'I' && i != 7)
1115             *p++ = ':';
1116     }
1117     *p = '\0';
1118 
1119     return p;
1120 }
1121 
1122 static noinline_for_stack
1123 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1124               struct printf_spec spec, const char *fmt)
1125 {
1126     char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1127 
1128     if (fmt[0] == 'I' && fmt[2] == 'c')
1129         ip6_compressed_string(ip6_addr, addr);
1130     else
1131         ip6_string(ip6_addr, addr, fmt);
1132 
1133     return string(buf, end, ip6_addr, spec);
1134 }
1135 
1136 static noinline_for_stack
1137 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1138               struct printf_spec spec, const char *fmt)
1139 {
1140     char ip4_addr[sizeof("255.255.255.255")];
1141 
1142     ip4_string(ip4_addr, addr, fmt);
1143 
1144     return string(buf, end, ip4_addr, spec);
1145 }
1146 
1147 static noinline_for_stack
1148 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1149              struct printf_spec spec, const char *fmt)
1150 {
1151     bool have_p = false, have_s = false, have_f = false, have_c = false;
1152     char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1153               sizeof(":12345") + sizeof("/123456789") +
1154               sizeof("%1234567890")];
1155     char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1156     const u8 *addr = (const u8 *) &sa->sin6_addr;
1157     char fmt6[2] = { fmt[0], '6' };
1158     u8 off = 0;
1159 
1160     fmt++;
1161     while (isalpha(*++fmt)) {
1162         switch (*fmt) {
1163         case 'p':
1164             have_p = true;
1165             break;
1166         case 'f':
1167             have_f = true;
1168             break;
1169         case 's':
1170             have_s = true;
1171             break;
1172         case 'c':
1173             have_c = true;
1174             break;
1175         }
1176     }
1177 
1178     if (have_p || have_s || have_f) {
1179         *p = '[';
1180         off = 1;
1181     }
1182 
1183     if (fmt6[0] == 'I' && have_c)
1184         p = ip6_compressed_string(ip6_addr + off, addr);
1185     else
1186         p = ip6_string(ip6_addr + off, addr, fmt6);
1187 
1188     if (have_p || have_s || have_f)
1189         *p++ = ']';
1190 
1191     if (have_p) {
1192         *p++ = ':';
1193         p = number(p, pend, ntohs(sa->sin6_port), spec);
1194     }
1195     if (have_f) {
1196         *p++ = '/';
1197         p = number(p, pend, ntohl(sa->sin6_flowinfo &
1198                       IPV6_FLOWINFO_MASK), spec);
1199     }
1200     if (have_s) {
1201         *p++ = '%';
1202         p = number(p, pend, sa->sin6_scope_id, spec);
1203     }
1204     *p = '\0';
1205 
1206     return string(buf, end, ip6_addr, spec);
1207 }
1208 
1209 static noinline_for_stack
1210 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1211              struct printf_spec spec, const char *fmt)
1212 {
1213     bool have_p = false;
1214     char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1215     char *pend = ip4_addr + sizeof(ip4_addr);
1216     const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1217     char fmt4[3] = { fmt[0], '4', 0 };
1218 
1219     fmt++;
1220     while (isalpha(*++fmt)) {
1221         switch (*fmt) {
1222         case 'p':
1223             have_p = true;
1224             break;
1225         case 'h':
1226         case 'l':
1227         case 'n':
1228         case 'b':
1229             fmt4[2] = *fmt;
1230             break;
1231         }
1232     }
1233 
1234     p = ip4_string(ip4_addr, addr, fmt4);
1235     if (have_p) {
1236         *p++ = ':';
1237         p = number(p, pend, ntohs(sa->sin_port), spec);
1238     }
1239     *p = '\0';
1240 
1241     return string(buf, end, ip4_addr, spec);
1242 }
1243 
1244 static noinline_for_stack
1245 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1246              const char *fmt)
1247 {
1248     bool found = true;
1249     int count = 1;
1250     unsigned int flags = 0;
1251     int len;
1252 
1253     if (spec.field_width == 0)
1254         return buf;             /* nothing to print */
1255 
1256     if (ZERO_OR_NULL_PTR(addr))
1257         return string(buf, end, NULL, spec);    /* NULL pointer */
1258 
1259 
1260     do {
1261         switch (fmt[count++]) {
1262         case 'a':
1263             flags |= ESCAPE_ANY;
1264             break;
1265         case 'c':
1266             flags |= ESCAPE_SPECIAL;
1267             break;
1268         case 'h':
1269             flags |= ESCAPE_HEX;
1270             break;
1271         case 'n':
1272             flags |= ESCAPE_NULL;
1273             break;
1274         case 'o':
1275             flags |= ESCAPE_OCTAL;
1276             break;
1277         case 'p':
1278             flags |= ESCAPE_NP;
1279             break;
1280         case 's':
1281             flags |= ESCAPE_SPACE;
1282             break;
1283         default:
1284             found = false;
1285             break;
1286         }
1287     } while (found);
1288 
1289     if (!flags)
1290         flags = ESCAPE_ANY_NP;
1291 
1292     len = spec.field_width < 0 ? 1 : spec.field_width;
1293 
1294     /*
1295      * string_escape_mem() writes as many characters as it can to
1296      * the given buffer, and returns the total size of the output
1297      * had the buffer been big enough.
1298      */
1299     buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1300 
1301     return buf;
1302 }
1303 
1304 static noinline_for_stack
1305 char *uuid_string(char *buf, char *end, const u8 *addr,
1306           struct printf_spec spec, const char *fmt)
1307 {
1308     char uuid[UUID_STRING_LEN + 1];
1309     char *p = uuid;
1310     int i;
1311     const u8 *index = uuid_be_index;
1312     bool uc = false;
1313 
1314     switch (*(++fmt)) {
1315     case 'L':
1316         uc = true;      /* fall-through */
1317     case 'l':
1318         index = uuid_le_index;
1319         break;
1320     case 'B':
1321         uc = true;
1322         break;
1323     }
1324 
1325     for (i = 0; i < 16; i++) {
1326         if (uc)
1327             p = hex_byte_pack_upper(p, addr[index[i]]);
1328         else
1329             p = hex_byte_pack(p, addr[index[i]]);
1330         switch (i) {
1331         case 3:
1332         case 5:
1333         case 7:
1334         case 9:
1335             *p++ = '-';
1336             break;
1337         }
1338     }
1339 
1340     *p = 0;
1341 
1342     return string(buf, end, uuid, spec);
1343 }
1344 
1345 static noinline_for_stack
1346 char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1347 {
1348     unsigned long long num;
1349     int size;
1350 
1351     switch (fmt[1]) {
1352     case 'F':
1353         num = *(const netdev_features_t *)addr;
1354         size = sizeof(netdev_features_t);
1355         break;
1356     default:
1357         num = (unsigned long)addr;
1358         size = sizeof(unsigned long);
1359         break;
1360     }
1361 
1362     return special_hex_number(buf, end, num, size);
1363 }
1364 
1365 static noinline_for_stack
1366 char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1367 {
1368     unsigned long long num;
1369     int size;
1370 
1371     switch (fmt[1]) {
1372     case 'd':
1373         num = *(const dma_addr_t *)addr;
1374         size = sizeof(dma_addr_t);
1375         break;
1376     case 'p':
1377     default:
1378         num = *(const phys_addr_t *)addr;
1379         size = sizeof(phys_addr_t);
1380         break;
1381     }
1382 
1383     return special_hex_number(buf, end, num, size);
1384 }
1385 
1386 static noinline_for_stack
1387 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1388         const char *fmt)
1389 {
1390     if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1391         return string(buf, end, NULL, spec);
1392 
1393     switch (fmt[1]) {
1394     case 'r':
1395         return number(buf, end, clk_get_rate(clk), spec);
1396 
1397     case 'n':
1398     default:
1399 #ifdef CONFIG_COMMON_CLK
1400         return string(buf, end, __clk_get_name(clk), spec);
1401 #else
1402         return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1403 #endif
1404     }
1405 }
1406 
1407 static
1408 char *format_flags(char *buf, char *end, unsigned long flags,
1409                     const struct trace_print_flags *names)
1410 {
1411     unsigned long mask;
1412     const struct printf_spec strspec = {
1413         .field_width = -1,
1414         .precision = -1,
1415     };
1416     const struct printf_spec numspec = {
1417         .flags = SPECIAL|SMALL,
1418         .field_width = -1,
1419         .precision = -1,
1420         .base = 16,
1421     };
1422 
1423     for ( ; flags && names->name; names++) {
1424         mask = names->mask;
1425         if ((flags & mask) != mask)
1426             continue;
1427 
1428         buf = string(buf, end, names->name, strspec);
1429 
1430         flags &= ~mask;
1431         if (flags) {
1432             if (buf < end)
1433                 *buf = '|';
1434             buf++;
1435         }
1436     }
1437 
1438     if (flags)
1439         buf = number(buf, end, flags, numspec);
1440 
1441     return buf;
1442 }
1443 
1444 static noinline_for_stack
1445 char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1446 {
1447     unsigned long flags;
1448     const struct trace_print_flags *names;
1449 
1450     switch (fmt[1]) {
1451     case 'p':
1452         flags = *(unsigned long *)flags_ptr;
1453         /* Remove zone id */
1454         flags &= (1UL << NR_PAGEFLAGS) - 1;
1455         names = pageflag_names;
1456         break;
1457     case 'v':
1458         flags = *(unsigned long *)flags_ptr;
1459         names = vmaflag_names;
1460         break;
1461     case 'g':
1462         flags = *(gfp_t *)flags_ptr;
1463         names = gfpflag_names;
1464         break;
1465     default:
1466         WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1467         return buf;
1468     }
1469 
1470     return format_flags(buf, end, flags, names);
1471 }
1472 
1473 int kptr_restrict __read_mostly;
1474 
1475 /*
1476  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
1477  * by an extra set of alphanumeric characters that are extended format
1478  * specifiers.
1479  *
1480  * Right now we handle:
1481  *
1482  * - 'F' For symbolic function descriptor pointers with offset
1483  * - 'f' For simple symbolic function names without offset
1484  * - 'S' For symbolic direct pointers with offset
1485  * - 's' For symbolic direct pointers without offset
1486  * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1487  * - 'B' For backtraced symbolic direct pointers with offset
1488  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1489  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1490  * - 'b[l]' For a bitmap, the number of bits is determined by the field
1491  *       width which must be explicitly specified either as part of the
1492  *       format string '%32b[l]' or through '%*b[l]', [l] selects
1493  *       range-list format instead of hex format
1494  * - 'M' For a 6-byte MAC address, it prints the address in the
1495  *       usual colon-separated hex notation
1496  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1497  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1498  *       with a dash-separated hex notation
1499  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1500  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1501  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1502  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
1503  *       [S][pfs]
1504  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1505  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1506  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1507  *       IPv6 omits the colons (01020304...0f)
1508  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1509  *       [S][pfs]
1510  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1511  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1512  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1513  * - 'I[6S]c' for IPv6 addresses printed as specified by
1514  *       http://tools.ietf.org/html/rfc5952
1515  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1516  *                of the following flags (see string_escape_mem() for the
1517  *                details):
1518  *                  a - ESCAPE_ANY
1519  *                  c - ESCAPE_SPECIAL
1520  *                  h - ESCAPE_HEX
1521  *                  n - ESCAPE_NULL
1522  *                  o - ESCAPE_OCTAL
1523  *                  p - ESCAPE_NP
1524  *                  s - ESCAPE_SPACE
1525  *                By default ESCAPE_ANY_NP is used.
1526  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1527  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1528  *       Options for %pU are:
1529  *         b big endian lower case hex (default)
1530  *         B big endian UPPER case hex
1531  *         l little endian lower case hex
1532  *         L little endian UPPER case hex
1533  *           big endian output byte order is:
1534  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1535  *           little endian output byte order is:
1536  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1537  * - 'V' For a struct va_format which contains a format string * and va_list *,
1538  *       call vsnprintf(->format, *->va_list).
1539  *       Implements a "recursive vsnprintf".
1540  *       Do not use this feature without some mechanism to verify the
1541  *       correctness of the format string and va_list arguments.
1542  * - 'K' For a kernel pointer that should be hidden from unprivileged users
1543  * - 'NF' For a netdev_features_t
1544  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1545  *            a certain separator (' ' by default):
1546  *              C colon
1547  *              D dash
1548  *              N no separator
1549  *            The maximum supported length is 64 bytes of the input. Consider
1550  *            to use print_hex_dump() for the larger input.
1551  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1552  *           (default assumed to be phys_addr_t, passed by reference)
1553  * - 'd[234]' For a dentry name (optionally 2-4 last components)
1554  * - 'D[234]' Same as 'd' but for a struct file
1555  * - 'g' For block_device name (gendisk + partition number)
1556  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1557  *       (legacy clock framework) of the clock
1558  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1559  *        (legacy clock framework) of the clock
1560  * - 'Cr' For a clock, it prints the current rate of the clock
1561  * - 'G' For flags to be printed as a collection of symbolic strings that would
1562  *       construct the specific value. Supported flags given by option:
1563  *       p page flags (see struct page) given as pointer to unsigned long
1564  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1565  *       v vma flags (VM_*) given as pointer to unsigned long
1566  *
1567  * ** Please update also Documentation/printk-formats.txt when making changes **
1568  *
1569  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1570  * function pointers are really function descriptors, which contain a
1571  * pointer to the real address.
1572  */
1573 static noinline_for_stack
1574 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1575           struct printf_spec spec)
1576 {
1577     const int default_width = 2 * sizeof(void *);
1578 
1579     if (!ptr && *fmt != 'K') {
1580         /*
1581          * Print (null) with the same width as a pointer so it makes
1582          * tabular output look nice.
1583          */
1584         if (spec.field_width == -1)
1585             spec.field_width = default_width;
1586         return string(buf, end, "(null)", spec);
1587     }
1588 
1589     switch (*fmt) {
1590     case 'F':
1591     case 'f':
1592         ptr = dereference_function_descriptor(ptr);
1593         /* Fallthrough */
1594     case 'S':
1595     case 's':
1596     case 'B':
1597         return symbol_string(buf, end, ptr, spec, fmt);
1598     case 'R':
1599     case 'r':
1600         return resource_string(buf, end, ptr, spec, fmt);
1601     case 'h':
1602         return hex_string(buf, end, ptr, spec, fmt);
1603     case 'b':
1604         switch (fmt[1]) {
1605         case 'l':
1606             return bitmap_list_string(buf, end, ptr, spec, fmt);
1607         default:
1608             return bitmap_string(buf, end, ptr, spec, fmt);
1609         }
1610     case 'M':           /* Colon separated: 00:01:02:03:04:05 */
1611     case 'm':           /* Contiguous: 000102030405 */
1612                     /* [mM]F (FDDI) */
1613                     /* [mM]R (Reverse order; Bluetooth) */
1614         return mac_address_string(buf, end, ptr, spec, fmt);
1615     case 'I':           /* Formatted IP supported
1616                      * 4:   1.2.3.4
1617                      * 6:   0001:0203:...:0708
1618                      * 6c:  1::708 or 1::1.2.3.4
1619                      */
1620     case 'i':           /* Contiguous:
1621                      * 4:   001.002.003.004
1622                      * 6:   000102...0f
1623                      */
1624         switch (fmt[1]) {
1625         case '6':
1626             return ip6_addr_string(buf, end, ptr, spec, fmt);
1627         case '4':
1628             return ip4_addr_string(buf, end, ptr, spec, fmt);
1629         case 'S': {
1630             const union {
1631                 struct sockaddr     raw;
1632                 struct sockaddr_in  v4;
1633                 struct sockaddr_in6 v6;
1634             } *sa = ptr;
1635 
1636             switch (sa->raw.sa_family) {
1637             case AF_INET:
1638                 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1639             case AF_INET6:
1640                 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1641             default:
1642                 return string(buf, end, "(invalid address)", spec);
1643             }}
1644         }
1645         break;
1646     case 'E':
1647         return escaped_string(buf, end, ptr, spec, fmt);
1648     case 'U':
1649         return uuid_string(buf, end, ptr, spec, fmt);
1650     case 'V':
1651         {
1652             va_list va;
1653 
1654             va_copy(va, *((struct va_format *)ptr)->va);
1655             buf += vsnprintf(buf, end > buf ? end - buf : 0,
1656                      ((struct va_format *)ptr)->fmt, va);
1657             va_end(va);
1658             return buf;
1659         }
1660     case 'K':
1661         switch (kptr_restrict) {
1662         case 0:
1663             /* Always print %pK values */
1664             break;
1665         case 1: {
1666             const struct cred *cred;
1667 
1668             /*
1669              * kptr_restrict==1 cannot be used in IRQ context
1670              * because its test for CAP_SYSLOG would be meaningless.
1671              */
1672             if (in_irq() || in_serving_softirq() || in_nmi()) {
1673                 if (spec.field_width == -1)
1674                     spec.field_width = default_width;
1675                 return string(buf, end, "pK-error", spec);
1676             }
1677 
1678             /*
1679              * Only print the real pointer value if the current
1680              * process has CAP_SYSLOG and is running with the
1681              * same credentials it started with. This is because
1682              * access to files is checked at open() time, but %pK
1683              * checks permission at read() time. We don't want to
1684              * leak pointer values if a binary opens a file using
1685              * %pK and then elevates privileges before reading it.
1686              */
1687             cred = current_cred();
1688             if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1689                 !uid_eq(cred->euid, cred->uid) ||
1690                 !gid_eq(cred->egid, cred->gid))
1691                 ptr = NULL;
1692             break;
1693         }
1694         case 2:
1695         default:
1696             /* Always print 0's for %pK */
1697             ptr = NULL;
1698             break;
1699         }
1700         break;
1701 
1702     case 'N':
1703         return netdev_bits(buf, end, ptr, fmt);
1704     case 'a':
1705         return address_val(buf, end, ptr, fmt);
1706     case 'd':
1707         return dentry_name(buf, end, ptr, spec, fmt);
1708     case 'C':
1709         return clock(buf, end, ptr, spec, fmt);
1710     case 'D':
1711         return dentry_name(buf, end,
1712                    ((const struct file *)ptr)->f_path.dentry,
1713                    spec, fmt);
1714 #ifdef CONFIG_BLOCK
1715     case 'g':
1716         return bdev_name(buf, end, ptr, spec, fmt);
1717 #endif
1718 
1719     case 'G':
1720         return flags_string(buf, end, ptr, fmt);
1721     }
1722     spec.flags |= SMALL;
1723     if (spec.field_width == -1) {
1724         spec.field_width = default_width;
1725         spec.flags |= ZEROPAD;
1726     }
1727     spec.base = 16;
1728 
1729     return number(buf, end, (unsigned long) ptr, spec);
1730 }
1731 
1732 /*
1733  * Helper function to decode printf style format.
1734  * Each call decode a token from the format and return the
1735  * number of characters read (or likely the delta where it wants
1736  * to go on the next call).
1737  * The decoded token is returned through the parameters
1738  *
1739  * 'h', 'l', or 'L' for integer fields
1740  * 'z' support added 23/7/1999 S.H.
1741  * 'z' changed to 'Z' --davidm 1/25/99
1742  * 't' added for ptrdiff_t
1743  *
1744  * @fmt: the format string
1745  * @type of the token returned
1746  * @flags: various flags such as +, -, # tokens..
1747  * @field_width: overwritten width
1748  * @base: base of the number (octal, hex, ...)
1749  * @precision: precision of a number
1750  * @qualifier: qualifier of a number (long, size_t, ...)
1751  */
1752 static noinline_for_stack
1753 int format_decode(const char *fmt, struct printf_spec *spec)
1754 {
1755     const char *start = fmt;
1756     char qualifier;
1757 
1758     /* we finished early by reading the field width */
1759     if (spec->type == FORMAT_TYPE_WIDTH) {
1760         if (spec->field_width < 0) {
1761             spec->field_width = -spec->field_width;
1762             spec->flags |= LEFT;
1763         }
1764         spec->type = FORMAT_TYPE_NONE;
1765         goto precision;
1766     }
1767 
1768     /* we finished early by reading the precision */
1769     if (spec->type == FORMAT_TYPE_PRECISION) {
1770         if (spec->precision < 0)
1771             spec->precision = 0;
1772 
1773         spec->type = FORMAT_TYPE_NONE;
1774         goto qualifier;
1775     }
1776 
1777     /* By default */
1778     spec->type = FORMAT_TYPE_NONE;
1779 
1780     for (; *fmt ; ++fmt) {
1781         if (*fmt == '%')
1782             break;
1783     }
1784 
1785     /* Return the current non-format string */
1786     if (fmt != start || !*fmt)
1787         return fmt - start;
1788 
1789     /* Process flags */
1790     spec->flags = 0;
1791 
1792     while (1) { /* this also skips first '%' */
1793         bool found = true;
1794 
1795         ++fmt;
1796 
1797         switch (*fmt) {
1798         case '-': spec->flags |= LEFT;    break;
1799         case '+': spec->flags |= PLUS;    break;
1800         case ' ': spec->flags |= SPACE;   break;
1801         case '#': spec->flags |= SPECIAL; break;
1802         case '0': spec->flags |= ZEROPAD; break;
1803         default:  found = false;
1804         }
1805 
1806         if (!found)
1807             break;
1808     }
1809 
1810     /* get field width */
1811     spec->field_width = -1;
1812 
1813     if (isdigit(*fmt))
1814         spec->field_width = skip_atoi(&fmt);
1815     else if (*fmt == '*') {
1816         /* it's the next argument */
1817         spec->type = FORMAT_TYPE_WIDTH;
1818         return ++fmt - start;
1819     }
1820 
1821 precision:
1822     /* get the precision */
1823     spec->precision = -1;
1824     if (*fmt == '.') {
1825         ++fmt;
1826         if (isdigit(*fmt)) {
1827             spec->precision = skip_atoi(&fmt);
1828             if (spec->precision < 0)
1829                 spec->precision = 0;
1830         } else if (*fmt == '*') {
1831             /* it's the next argument */
1832             spec->type = FORMAT_TYPE_PRECISION;
1833             return ++fmt - start;
1834         }
1835     }
1836 
1837 qualifier:
1838     /* get the conversion qualifier */
1839     qualifier = 0;
1840     if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
1841         _tolower(*fmt) == 'z' || *fmt == 't') {
1842         qualifier = *fmt++;
1843         if (unlikely(qualifier == *fmt)) {
1844             if (qualifier == 'l') {
1845                 qualifier = 'L';
1846                 ++fmt;
1847             } else if (qualifier == 'h') {
1848                 qualifier = 'H';
1849                 ++fmt;
1850             }
1851         }
1852     }
1853 
1854     /* default base */
1855     spec->base = 10;
1856     switch (*fmt) {
1857     case 'c':
1858         spec->type = FORMAT_TYPE_CHAR;
1859         return ++fmt - start;
1860 
1861     case 's':
1862         spec->type = FORMAT_TYPE_STR;
1863         return ++fmt - start;
1864 
1865     case 'p':
1866         spec->type = FORMAT_TYPE_PTR;
1867         return ++fmt - start;
1868 
1869     case '%':
1870         spec->type = FORMAT_TYPE_PERCENT_CHAR;
1871         return ++fmt - start;
1872 
1873     /* integer number formats - set up the flags and "break" */
1874     case 'o':
1875         spec->base = 8;
1876         break;
1877 
1878     case 'x':
1879         spec->flags |= SMALL;
1880 
1881     case 'X':
1882         spec->base = 16;
1883         break;
1884 
1885     case 'd':
1886     case 'i':
1887         spec->flags |= SIGN;
1888     case 'u':
1889         break;
1890 
1891     case 'n':
1892         /*
1893          * Since %n poses a greater security risk than
1894          * utility, treat it as any other invalid or
1895          * unsupported format specifier.
1896          */
1897         /* Fall-through */
1898 
1899     default:
1900         WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
1901         spec->type = FORMAT_TYPE_INVALID;
1902         return fmt - start;
1903     }
1904 
1905     if (qualifier == 'L')
1906         spec->type = FORMAT_TYPE_LONG_LONG;
1907     else if (qualifier == 'l') {
1908         BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
1909         spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
1910     } else if (_tolower(qualifier) == 'z') {
1911         spec->type = FORMAT_TYPE_SIZE_T;
1912     } else if (qualifier == 't') {
1913         spec->type = FORMAT_TYPE_PTRDIFF;
1914     } else if (qualifier == 'H') {
1915         BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
1916         spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
1917     } else if (qualifier == 'h') {
1918         BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
1919         spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
1920     } else {
1921         BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
1922         spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
1923     }
1924 
1925     return ++fmt - start;
1926 }
1927 
1928 static void
1929 set_field_width(struct printf_spec *spec, int width)
1930 {
1931     spec->field_width = width;
1932     if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
1933         spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
1934     }
1935 }
1936 
1937 static void
1938 set_precision(struct printf_spec *spec, int prec)
1939 {
1940     spec->precision = prec;
1941     if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
1942         spec->precision = clamp(prec, 0, PRECISION_MAX);
1943     }
1944 }
1945 
1946 /**
1947  * vsnprintf - Format a string and place it in a buffer
1948  * @buf: The buffer to place the result into
1949  * @size: The size of the buffer, including the trailing null space
1950  * @fmt: The format string to use
1951  * @args: Arguments for the format string
1952  *
1953  * This function generally follows C99 vsnprintf, but has some
1954  * extensions and a few limitations:
1955  *
1956  * %n is unsupported
1957  * %p* is handled by pointer()
1958  *
1959  * See pointer() or Documentation/printk-formats.txt for more
1960  * extensive description.
1961  *
1962  * ** Please update the documentation in both places when making changes **
1963  *
1964  * The return value is the number of characters which would
1965  * be generated for the given input, excluding the trailing
1966  * '\0', as per ISO C99. If you want to have the exact
1967  * number of characters written into @buf as return value
1968  * (not including the trailing '\0'), use vscnprintf(). If the
1969  * return is greater than or equal to @size, the resulting
1970  * string is truncated.
1971  *
1972  * If you're not already dealing with a va_list consider using snprintf().
1973  */
1974 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
1975 {
1976     unsigned long long num;
1977     char *str, *end;
1978     struct printf_spec spec = {0};
1979 
1980     /* Reject out-of-range values early.  Large positive sizes are
1981        used for unknown buffer sizes. */
1982     if (WARN_ON_ONCE(size > INT_MAX))
1983         return 0;
1984 
1985     str = buf;
1986     end = buf + size;
1987 
1988     /* Make sure end is always >= buf */
1989     if (end < buf) {
1990         end = ((void *)-1);
1991         size = end - buf;
1992     }
1993 
1994     while (*fmt) {
1995         const char *old_fmt = fmt;
1996         int read = format_decode(fmt, &spec);
1997 
1998         fmt += read;
1999 
2000         switch (spec.type) {
2001         case FORMAT_TYPE_NONE: {
2002             int copy = read;
2003             if (str < end) {
2004                 if (copy > end - str)
2005                     copy = end - str;
2006                 memcpy(str, old_fmt, copy);
2007             }
2008             str += read;
2009             break;
2010         }
2011 
2012         case FORMAT_TYPE_WIDTH:
2013             set_field_width(&spec, va_arg(args, int));
2014             break;
2015 
2016         case FORMAT_TYPE_PRECISION:
2017             set_precision(&spec, va_arg(args, int));
2018             break;
2019 
2020         case FORMAT_TYPE_CHAR: {
2021             char c;
2022 
2023             if (!(spec.flags & LEFT)) {
2024                 while (--spec.field_width > 0) {
2025                     if (str < end)
2026                         *str = ' ';
2027                     ++str;
2028 
2029                 }
2030             }
2031             c = (unsigned char) va_arg(args, int);
2032             if (str < end)
2033                 *str = c;
2034             ++str;
2035             while (--spec.field_width > 0) {
2036                 if (str < end)
2037                     *str = ' ';
2038                 ++str;
2039             }
2040             break;
2041         }
2042 
2043         case FORMAT_TYPE_STR:
2044             str = string(str, end, va_arg(args, char *), spec);
2045             break;
2046 
2047         case FORMAT_TYPE_PTR:
2048             str = pointer(fmt, str, end, va_arg(args, void *),
2049                       spec);
2050             while (isalnum(*fmt))
2051                 fmt++;
2052             break;
2053 
2054         case FORMAT_TYPE_PERCENT_CHAR:
2055             if (str < end)
2056                 *str = '%';
2057             ++str;
2058             break;
2059 
2060         case FORMAT_TYPE_INVALID:
2061             /*
2062              * Presumably the arguments passed gcc's type
2063              * checking, but there is no safe or sane way
2064              * for us to continue parsing the format and
2065              * fetching from the va_list; the remaining
2066              * specifiers and arguments would be out of
2067              * sync.
2068              */
2069             goto out;
2070 
2071         default:
2072             switch (spec.type) {
2073             case FORMAT_TYPE_LONG_LONG:
2074                 num = va_arg(args, long long);
2075                 break;
2076             case FORMAT_TYPE_ULONG:
2077                 num = va_arg(args, unsigned long);
2078                 break;
2079             case FORMAT_TYPE_LONG:
2080                 num = va_arg(args, long);
2081                 break;
2082             case FORMAT_TYPE_SIZE_T:
2083                 if (spec.flags & SIGN)
2084                     num = va_arg(args, ssize_t);
2085                 else
2086                     num = va_arg(args, size_t);
2087                 break;
2088             case FORMAT_TYPE_PTRDIFF:
2089                 num = va_arg(args, ptrdiff_t);
2090                 break;
2091             case FORMAT_TYPE_UBYTE:
2092                 num = (unsigned char) va_arg(args, int);
2093                 break;
2094             case FORMAT_TYPE_BYTE:
2095                 num = (signed char) va_arg(args, int);
2096                 break;
2097             case FORMAT_TYPE_USHORT:
2098                 num = (unsigned short) va_arg(args, int);
2099                 break;
2100             case FORMAT_TYPE_SHORT:
2101                 num = (short) va_arg(args, int);
2102                 break;
2103             case FORMAT_TYPE_INT:
2104                 num = (int) va_arg(args, int);
2105                 break;
2106             default:
2107                 num = va_arg(args, unsigned int);
2108             }
2109 
2110             str = number(str, end, num, spec);
2111         }
2112     }
2113 
2114 out:
2115     if (size > 0) {
2116         if (str < end)
2117             *str = '\0';
2118         else
2119             end[-1] = '\0';
2120     }
2121 
2122     /* the trailing null byte doesn't count towards the total */
2123     return str-buf;
2124 
2125 }
2126 EXPORT_SYMBOL(vsnprintf);
2127 
2128 /**
2129  * vscnprintf - Format a string and place it in a buffer
2130  * @buf: The buffer to place the result into
2131  * @size: The size of the buffer, including the trailing null space
2132  * @fmt: The format string to use
2133  * @args: Arguments for the format string
2134  *
2135  * The return value is the number of characters which have been written into
2136  * the @buf not including the trailing '\0'. If @size is == 0 the function
2137  * returns 0.
2138  *
2139  * If you're not already dealing with a va_list consider using scnprintf().
2140  *
2141  * See the vsnprintf() documentation for format string extensions over C99.
2142  */
2143 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2144 {
2145     int i;
2146 
2147     i = vsnprintf(buf, size, fmt, args);
2148 
2149     if (likely(i < size))
2150         return i;
2151     if (size != 0)
2152         return size - 1;
2153     return 0;
2154 }
2155 EXPORT_SYMBOL(vscnprintf);
2156 
2157 /**
2158  * snprintf - Format a string and place it in a buffer
2159  * @buf: The buffer to place the result into
2160  * @size: The size of the buffer, including the trailing null space
2161  * @fmt: The format string to use
2162  * @...: Arguments for the format string
2163  *
2164  * The return value is the number of characters which would be
2165  * generated for the given input, excluding the trailing null,
2166  * as per ISO C99.  If the return is greater than or equal to
2167  * @size, the resulting string is truncated.
2168  *
2169  * See the vsnprintf() documentation for format string extensions over C99.
2170  */
2171 int snprintf(char *buf, size_t size, const char *fmt, ...)
2172 {
2173     va_list args;
2174     int i;
2175 
2176     va_start(args, fmt);
2177     i = vsnprintf(buf, size, fmt, args);
2178     va_end(args);
2179 
2180     return i;
2181 }
2182 EXPORT_SYMBOL(snprintf);
2183 
2184 /**
2185  * scnprintf - Format a string and place it in a buffer
2186  * @buf: The buffer to place the result into
2187  * @size: The size of the buffer, including the trailing null space
2188  * @fmt: The format string to use
2189  * @...: Arguments for the format string
2190  *
2191  * The return value is the number of characters written into @buf not including
2192  * the trailing '\0'. If @size is == 0 the function returns 0.
2193  */
2194 
2195 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2196 {
2197     va_list args;
2198     int i;
2199 
2200     va_start(args, fmt);
2201     i = vscnprintf(buf, size, fmt, args);
2202     va_end(args);
2203 
2204     return i;
2205 }
2206 EXPORT_SYMBOL(scnprintf);
2207 
2208 /**
2209  * vsprintf - Format a string and place it in a buffer
2210  * @buf: The buffer to place the result into
2211  * @fmt: The format string to use
2212  * @args: Arguments for the format string
2213  *
2214  * The function returns the number of characters written
2215  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2216  * buffer overflows.
2217  *
2218  * If you're not already dealing with a va_list consider using sprintf().
2219  *
2220  * See the vsnprintf() documentation for format string extensions over C99.
2221  */
2222 int vsprintf(char *buf, const char *fmt, va_list args)
2223 {
2224     return vsnprintf(buf, INT_MAX, fmt, args);
2225 }
2226 EXPORT_SYMBOL(vsprintf);
2227 
2228 /**
2229  * sprintf - Format a string and place it in a buffer
2230  * @buf: The buffer to place the result into
2231  * @fmt: The format string to use
2232  * @...: Arguments for the format string
2233  *
2234  * The function returns the number of characters written
2235  * into @buf. Use snprintf() or scnprintf() in order to avoid
2236  * buffer overflows.
2237  *
2238  * See the vsnprintf() documentation for format string extensions over C99.
2239  */
2240 int sprintf(char *buf, const char *fmt, ...)
2241 {
2242     va_list args;
2243     int i;
2244 
2245     va_start(args, fmt);
2246     i = vsnprintf(buf, INT_MAX, fmt, args);
2247     va_end(args);
2248 
2249     return i;
2250 }
2251 EXPORT_SYMBOL(sprintf);
2252 
2253 #ifdef CONFIG_BINARY_PRINTF
2254 /*
2255  * bprintf service:
2256  * vbin_printf() - VA arguments to binary data
2257  * bstr_printf() - Binary data to text string
2258  */
2259 
2260 /**
2261  * vbin_printf - Parse a format string and place args' binary value in a buffer
2262  * @bin_buf: The buffer to place args' binary value
2263  * @size: The size of the buffer(by words(32bits), not characters)
2264  * @fmt: The format string to use
2265  * @args: Arguments for the format string
2266  *
2267  * The format follows C99 vsnprintf, except %n is ignored, and its argument
2268  * is skipped.
2269  *
2270  * The return value is the number of words(32bits) which would be generated for
2271  * the given input.
2272  *
2273  * NOTE:
2274  * If the return value is greater than @size, the resulting bin_buf is NOT
2275  * valid for bstr_printf().
2276  */
2277 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2278 {
2279     struct printf_spec spec = {0};
2280     char *str, *end;
2281 
2282     str = (char *)bin_buf;
2283     end = (char *)(bin_buf + size);
2284 
2285 #define save_arg(type)                          \
2286 do {                                    \
2287     if (sizeof(type) == 8) {                    \
2288         unsigned long long value;               \
2289         str = PTR_ALIGN(str, sizeof(u32));          \
2290         value = va_arg(args, unsigned long long);       \
2291         if (str + sizeof(type) <= end) {            \
2292             *(u32 *)str = *(u32 *)&value;           \
2293             *(u32 *)(str + 4) = *((u32 *)&value + 1);   \
2294         }                           \
2295     } else {                            \
2296         unsigned long value;                    \
2297         str = PTR_ALIGN(str, sizeof(type));         \
2298         value = va_arg(args, int);              \
2299         if (str + sizeof(type) <= end)              \
2300             *(typeof(type) *)str = (type)value;     \
2301     }                               \
2302     str += sizeof(type);                        \
2303 } while (0)
2304 
2305     while (*fmt) {
2306         int read = format_decode(fmt, &spec);
2307 
2308         fmt += read;
2309 
2310         switch (spec.type) {
2311         case FORMAT_TYPE_NONE:
2312         case FORMAT_TYPE_PERCENT_CHAR:
2313             break;
2314         case FORMAT_TYPE_INVALID:
2315             goto out;
2316 
2317         case FORMAT_TYPE_WIDTH:
2318         case FORMAT_TYPE_PRECISION:
2319             save_arg(int);
2320             break;
2321 
2322         case FORMAT_TYPE_CHAR:
2323             save_arg(char);
2324             break;
2325 
2326         case FORMAT_TYPE_STR: {
2327             const char *save_str = va_arg(args, char *);
2328             size_t len;
2329 
2330             if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2331                     || (unsigned long)save_str < PAGE_SIZE)
2332                 save_str = "(null)";
2333             len = strlen(save_str) + 1;
2334             if (str + len < end)
2335                 memcpy(str, save_str, len);
2336             str += len;
2337             break;
2338         }
2339 
2340         case FORMAT_TYPE_PTR:
2341             save_arg(void *);
2342             /* skip all alphanumeric pointer suffixes */
2343             while (isalnum(*fmt))
2344                 fmt++;
2345             break;
2346 
2347         default:
2348             switch (spec.type) {
2349 
2350             case FORMAT_TYPE_LONG_LONG:
2351                 save_arg(long long);
2352                 break;
2353             case FORMAT_TYPE_ULONG:
2354             case FORMAT_TYPE_LONG:
2355                 save_arg(unsigned long);
2356                 break;
2357             case FORMAT_TYPE_SIZE_T:
2358                 save_arg(size_t);
2359                 break;
2360             case FORMAT_TYPE_PTRDIFF:
2361                 save_arg(ptrdiff_t);
2362                 break;
2363             case FORMAT_TYPE_UBYTE:
2364             case FORMAT_TYPE_BYTE:
2365                 save_arg(char);
2366                 break;
2367             case FORMAT_TYPE_USHORT:
2368             case FORMAT_TYPE_SHORT:
2369                 save_arg(short);
2370                 break;
2371             default:
2372                 save_arg(int);
2373             }
2374         }
2375     }
2376 
2377 out:
2378     return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2379 #undef save_arg
2380 }
2381 EXPORT_SYMBOL_GPL(vbin_printf);
2382 
2383 /**
2384  * bstr_printf - Format a string from binary arguments and place it in a buffer
2385  * @buf: The buffer to place the result into
2386  * @size: The size of the buffer, including the trailing null space
2387  * @fmt: The format string to use
2388  * @bin_buf: Binary arguments for the format string
2389  *
2390  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2391  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2392  * a binary buffer that generated by vbin_printf.
2393  *
2394  * The format follows C99 vsnprintf, but has some extensions:
2395  *  see vsnprintf comment for details.
2396  *
2397  * The return value is the number of characters which would
2398  * be generated for the given input, excluding the trailing
2399  * '\0', as per ISO C99. If you want to have the exact
2400  * number of characters written into @buf as return value
2401  * (not including the trailing '\0'), use vscnprintf(). If the
2402  * return is greater than or equal to @size, the resulting
2403  * string is truncated.
2404  */
2405 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2406 {
2407     struct printf_spec spec = {0};
2408     char *str, *end;
2409     const char *args = (const char *)bin_buf;
2410 
2411     if (WARN_ON_ONCE(size > INT_MAX))
2412         return 0;
2413 
2414     str = buf;
2415     end = buf + size;
2416 
2417 #define get_arg(type)                           \
2418 ({                                  \
2419     typeof(type) value;                     \
2420     if (sizeof(type) == 8) {                    \
2421         args = PTR_ALIGN(args, sizeof(u32));            \
2422         *(u32 *)&value = *(u32 *)args;              \
2423         *((u32 *)&value + 1) = *(u32 *)(args + 4);      \
2424     } else {                            \
2425         args = PTR_ALIGN(args, sizeof(type));           \
2426         value = *(typeof(type) *)args;              \
2427     }                               \
2428     args += sizeof(type);                       \
2429     value;                              \
2430 })
2431 
2432     /* Make sure end is always >= buf */
2433     if (end < buf) {
2434         end = ((void *)-1);
2435         size = end - buf;
2436     }
2437 
2438     while (*fmt) {
2439         const char *old_fmt = fmt;
2440         int read = format_decode(fmt, &spec);
2441 
2442         fmt += read;
2443 
2444         switch (spec.type) {
2445         case FORMAT_TYPE_NONE: {
2446             int copy = read;
2447             if (str < end) {
2448                 if (copy > end - str)
2449                     copy = end - str;
2450                 memcpy(str, old_fmt, copy);
2451             }
2452             str += read;
2453             break;
2454         }
2455 
2456         case FORMAT_TYPE_WIDTH:
2457             set_field_width(&spec, get_arg(int));
2458             break;
2459 
2460         case FORMAT_TYPE_PRECISION:
2461             set_precision(&spec, get_arg(int));
2462             break;
2463 
2464         case FORMAT_TYPE_CHAR: {
2465             char c;
2466 
2467             if (!(spec.flags & LEFT)) {
2468                 while (--spec.field_width > 0) {
2469                     if (str < end)
2470                         *str = ' ';
2471                     ++str;
2472                 }
2473             }
2474             c = (unsigned char) get_arg(char);
2475             if (str < end)
2476                 *str = c;
2477             ++str;
2478             while (--spec.field_width > 0) {
2479                 if (str < end)
2480                     *str = ' ';
2481                 ++str;
2482             }
2483             break;
2484         }
2485 
2486         case FORMAT_TYPE_STR: {
2487             const char *str_arg = args;
2488             args += strlen(str_arg) + 1;
2489             str = string(str, end, (char *)str_arg, spec);
2490             break;
2491         }
2492 
2493         case FORMAT_TYPE_PTR:
2494             str = pointer(fmt, str, end, get_arg(void *), spec);
2495             while (isalnum(*fmt))
2496                 fmt++;
2497             break;
2498 
2499         case FORMAT_TYPE_PERCENT_CHAR:
2500             if (str < end)
2501                 *str = '%';
2502             ++str;
2503             break;
2504 
2505         case FORMAT_TYPE_INVALID:
2506             goto out;
2507 
2508         default: {
2509             unsigned long long num;
2510 
2511             switch (spec.type) {
2512 
2513             case FORMAT_TYPE_LONG_LONG:
2514                 num = get_arg(long long);
2515                 break;
2516             case FORMAT_TYPE_ULONG:
2517             case FORMAT_TYPE_LONG:
2518                 num = get_arg(unsigned long);
2519                 break;
2520             case FORMAT_TYPE_SIZE_T:
2521                 num = get_arg(size_t);
2522                 break;
2523             case FORMAT_TYPE_PTRDIFF:
2524                 num = get_arg(ptrdiff_t);
2525                 break;
2526             case FORMAT_TYPE_UBYTE:
2527                 num = get_arg(unsigned char);
2528                 break;
2529             case FORMAT_TYPE_BYTE:
2530                 num = get_arg(signed char);
2531                 break;
2532             case FORMAT_TYPE_USHORT:
2533                 num = get_arg(unsigned short);
2534                 break;
2535             case FORMAT_TYPE_SHORT:
2536                 num = get_arg(short);
2537                 break;
2538             case FORMAT_TYPE_UINT:
2539                 num = get_arg(unsigned int);
2540                 break;
2541             default:
2542                 num = get_arg(int);
2543             }
2544 
2545             str = number(str, end, num, spec);
2546         } /* default: */
2547         } /* switch(spec.type) */
2548     } /* while(*fmt) */
2549 
2550 out:
2551     if (size > 0) {
2552         if (str < end)
2553             *str = '\0';
2554         else
2555             end[-1] = '\0';
2556     }
2557 
2558 #undef get_arg
2559 
2560     /* the trailing null byte doesn't count towards the total */
2561     return str - buf;
2562 }
2563 EXPORT_SYMBOL_GPL(bstr_printf);
2564 
2565 /**
2566  * bprintf - Parse a format string and place args' binary value in a buffer
2567  * @bin_buf: The buffer to place args' binary value
2568  * @size: The size of the buffer(by words(32bits), not characters)
2569  * @fmt: The format string to use
2570  * @...: Arguments for the format string
2571  *
2572  * The function returns the number of words(u32) written
2573  * into @bin_buf.
2574  */
2575 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2576 {
2577     va_list args;
2578     int ret;
2579 
2580     va_start(args, fmt);
2581     ret = vbin_printf(bin_buf, size, fmt, args);
2582     va_end(args);
2583 
2584     return ret;
2585 }
2586 EXPORT_SYMBOL_GPL(bprintf);
2587 
2588 #endif /* CONFIG_BINARY_PRINTF */
2589 
2590 /**
2591  * vsscanf - Unformat a buffer into a list of arguments
2592  * @buf:    input buffer
2593  * @fmt:    format of buffer
2594  * @args:   arguments
2595  */
2596 int vsscanf(const char *buf, const char *fmt, va_list args)
2597 {
2598     const char *str = buf;
2599     char *next;
2600     char digit;
2601     int num = 0;
2602     u8 qualifier;
2603     unsigned int base;
2604     union {
2605         long long s;
2606         unsigned long long u;
2607     } val;
2608     s16 field_width;
2609     bool is_sign;
2610 
2611     while (*fmt) {
2612         /* skip any white space in format */
2613         /* white space in format matchs any amount of
2614          * white space, including none, in the input.
2615          */
2616         if (isspace(*fmt)) {
2617             fmt = skip_spaces(++fmt);
2618             str = skip_spaces(str);
2619         }
2620 
2621         /* anything that is not a conversion must match exactly */
2622         if (*fmt != '%' && *fmt) {
2623             if (*fmt++ != *str++)
2624                 break;
2625             continue;
2626         }
2627 
2628         if (!*fmt)
2629             break;
2630         ++fmt;
2631 
2632         /* skip this conversion.
2633          * advance both strings to next white space
2634          */
2635         if (*fmt == '*') {
2636             if (!*str)
2637                 break;
2638             while (!isspace(*fmt) && *fmt != '%' && *fmt) {
2639                 /* '%*[' not yet supported, invalid format */
2640                 if (*fmt == '[')
2641                     return num;
2642                 fmt++;
2643             }
2644             while (!isspace(*str) && *str)
2645                 str++;
2646             continue;
2647         }
2648 
2649         /* get field width */
2650         field_width = -1;
2651         if (isdigit(*fmt)) {
2652             field_width = skip_atoi(&fmt);
2653             if (field_width <= 0)
2654                 break;
2655         }
2656 
2657         /* get conversion qualifier */
2658         qualifier = -1;
2659         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2660             _tolower(*fmt) == 'z') {
2661             qualifier = *fmt++;
2662             if (unlikely(qualifier == *fmt)) {
2663                 if (qualifier == 'h') {
2664                     qualifier = 'H';
2665                     fmt++;
2666                 } else if (qualifier == 'l') {
2667                     qualifier = 'L';
2668                     fmt++;
2669                 }
2670             }
2671         }
2672 
2673         if (!*fmt)
2674             break;
2675 
2676         if (*fmt == 'n') {
2677             /* return number of characters read so far */
2678             *va_arg(args, int *) = str - buf;
2679             ++fmt;
2680             continue;
2681         }
2682 
2683         if (!*str)
2684             break;
2685 
2686         base = 10;
2687         is_sign = false;
2688 
2689         switch (*fmt++) {
2690         case 'c':
2691         {
2692             char *s = (char *)va_arg(args, char*);
2693             if (field_width == -1)
2694                 field_width = 1;
2695             do {
2696                 *s++ = *str++;
2697             } while (--field_width > 0 && *str);
2698             num++;
2699         }
2700         continue;
2701         case 's':
2702         {
2703             char *s = (char *)va_arg(args, char *);
2704             if (field_width == -1)
2705                 field_width = SHRT_MAX;
2706             /* first, skip leading white space in buffer */
2707             str = skip_spaces(str);
2708 
2709             /* now copy until next white space */
2710             while (*str && !isspace(*str) && field_width--)
2711                 *s++ = *str++;
2712             *s = '\0';
2713             num++;
2714         }
2715         continue;
2716         /*
2717          * Warning: This implementation of the '[' conversion specifier
2718          * deviates from its glibc counterpart in the following ways:
2719          * (1) It does NOT support ranges i.e. '-' is NOT a special
2720          *     character
2721          * (2) It cannot match the closing bracket ']' itself
2722          * (3) A field width is required
2723          * (4) '%*[' (discard matching input) is currently not supported
2724          *
2725          * Example usage:
2726          * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
2727          *      buf1, buf2, buf3);
2728          * if (ret < 3)
2729          *    // etc..
2730          */
2731         case '[':
2732         {
2733             char *s = (char *)va_arg(args, char *);
2734             DECLARE_BITMAP(set, 256) = {0};
2735             unsigned int len = 0;
2736             bool negate = (*fmt == '^');
2737 
2738             /* field width is required */
2739             if (field_width == -1)
2740                 return num;
2741 
2742             if (negate)
2743                 ++fmt;
2744 
2745             for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
2746                 set_bit((u8)*fmt, set);
2747 
2748             /* no ']' or no character set found */
2749             if (!*fmt || !len)
2750                 return num;
2751             ++fmt;
2752 
2753             if (negate) {
2754                 bitmap_complement(set, set, 256);
2755                 /* exclude null '\0' byte */
2756                 clear_bit(0, set);
2757             }
2758 
2759             /* match must be non-empty */
2760             if (!test_bit((u8)*str, set))
2761                 return num;
2762 
2763             while (test_bit((u8)*str, set) && field_width--)
2764                 *s++ = *str++;
2765             *s = '\0';
2766             ++num;
2767         }
2768         continue;
2769         case 'o':
2770             base = 8;
2771             break;
2772         case 'x':
2773         case 'X':
2774             base = 16;
2775             break;
2776         case 'i':
2777             base = 0;
2778         case 'd':
2779             is_sign = true;
2780         case 'u':
2781             break;
2782         case '%':
2783             /* looking for '%' in str */
2784             if (*str++ != '%')
2785                 return num;
2786             continue;
2787         default:
2788             /* invalid format; stop here */
2789             return num;
2790         }
2791 
2792         /* have some sort of integer conversion.
2793          * first, skip white space in buffer.
2794          */
2795         str = skip_spaces(str);
2796 
2797         digit = *str;
2798         if (is_sign && digit == '-')
2799             digit = *(str + 1);
2800 
2801         if (!digit
2802             || (base == 16 && !isxdigit(digit))
2803             || (base == 10 && !isdigit(digit))
2804             || (base == 8 && (!isdigit(digit) || digit > '7'))
2805             || (base == 0 && !isdigit(digit)))
2806             break;
2807 
2808         if (is_sign)
2809             val.s = qualifier != 'L' ?
2810                 simple_strtol(str, &next, base) :
2811                 simple_strtoll(str, &next, base);
2812         else
2813             val.u = qualifier != 'L' ?
2814                 simple_strtoul(str, &next, base) :
2815                 simple_strtoull(str, &next, base);
2816 
2817         if (field_width > 0 && next - str > field_width) {
2818             if (base == 0)
2819                 _parse_integer_fixup_radix(str, &base);
2820             while (next - str > field_width) {
2821                 if (is_sign)
2822                     val.s = div_s64(val.s, base);
2823                 else
2824                     val.u = div_u64(val.u, base);
2825                 --next;
2826             }
2827         }
2828 
2829         switch (qualifier) {
2830         case 'H':   /* that's 'hh' in format */
2831             if (is_sign)
2832                 *va_arg(args, signed char *) = val.s;
2833             else
2834                 *va_arg(args, unsigned char *) = val.u;
2835             break;
2836         case 'h':
2837             if (is_sign)
2838                 *va_arg(args, short *) = val.s;
2839             else
2840                 *va_arg(args, unsigned short *) = val.u;
2841             break;
2842         case 'l':
2843             if (is_sign)
2844                 *va_arg(args, long *) = val.s;
2845             else
2846                 *va_arg(args, unsigned long *) = val.u;
2847             break;
2848         case 'L':
2849             if (is_sign)
2850                 *va_arg(args, long long *) = val.s;
2851             else
2852                 *va_arg(args, unsigned long long *) = val.u;
2853             break;
2854         case 'Z':
2855         case 'z':
2856             *va_arg(args, size_t *) = val.u;
2857             break;
2858         default:
2859             if (is_sign)
2860                 *va_arg(args, int *) = val.s;
2861             else
2862                 *va_arg(args, unsigned int *) = val.u;
2863             break;
2864         }
2865         num++;
2866 
2867         if (!next)
2868             break;
2869         str = next;
2870     }
2871 
2872     return num;
2873 }
2874 EXPORT_SYMBOL(vsscanf);
2875 
2876 /**
2877  * sscanf - Unformat a buffer into a list of arguments
2878  * @buf:    input buffer
2879  * @fmt:    formatting of buffer
2880  * @...:    resulting arguments
2881  */
2882 int sscanf(const char *buf, const char *fmt, ...)
2883 {
2884     va_list args;
2885     int i;
2886 
2887     va_start(args, fmt);
2888     i = vsscanf(buf, fmt, args);
2889     va_end(args);
2890 
2891     return i;
2892 }
2893 EXPORT_SYMBOL(sscanf);