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 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/lib/vsprintf.c
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  */
 
 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
 /*
  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  */
 
 /*
  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  * - changed to provide snprintf and vsnprintf functions
  * So Feb  1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
  * - scnprintf and vscnprintf
  */
 
 #include <linux/stdarg.h>
 #include <linux/build_bug.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/errname.h>
 #include <linux/module.h>   /* for KSYM_SYMBOL_LEN */
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
 #include <linux/kernel.h>
 #include <linux/kallsyms.h>
 #include <linux/math64.h>
 #include <linux/uaccess.h>
 #include <linux/ioport.h>
 #include <linux/dcache.h>
 #include <linux/cred.h>
 #include <linux/rtc.h>
 #include <linux/time.h>
 #include <linux/uuid.h>
 #include <linux/of.h>
 #include <net/addrconf.h>
 #include <linux/siphash.h>
 #include <linux/compiler.h>
 #include <linux/property.h>
 #ifdef CONFIG_BLOCK
 #include <linux/blkdev.h>
 #endif
 
 #include "../mm/internal.h" /* For the trace_print_flags arrays */
 
 #include <asm/page.h>       /* for PAGE_SIZE */
 #include <asm/byteorder.h>  /* cpu_to_le16 */
 #include <asm/unaligned.h>
 
 #include <linux/string_helpers.h>
 #include "kstrtox.h"
 
 /* Disable pointer hashing if requested */
 bool no_hash_pointers __ro_after_init;
 EXPORT_SYMBOL_GPL(no_hash_pointers);
 
 static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
 {
     const char *cp;
     unsigned long long result = 0ULL;
     size_t prefix_chars;
     unsigned int rv;
 
     cp = _parse_integer_fixup_radix(startp, &base);
     prefix_chars = cp - startp;
     if (prefix_chars < max_chars) {
         rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
         /* FIXME */
         cp += (rv & ~KSTRTOX_OVERFLOW);
     } else {
         /* Field too short for prefix + digit, skip over without converting */
         cp = startp + max_chars;
     }
 
     if (endp)
         *endp = (char *)cp;
 
     return result;
 }
 
 /**
  * simple_strtoull - convert a string to an unsigned long long
  * @cp: The start of the string
  * @endp: A pointer to the end of the parsed string will be placed here
  * @base: The number base to use
  *
  * This function has caveats. Please use kstrtoull instead.
  */
 noinline
 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
 {
     return simple_strntoull(cp, INT_MAX, endp, base);
 }
 EXPORT_SYMBOL(simple_strtoull);
 
 /**
  * simple_strtoul - convert a string to an unsigned long
  * @cp: The start of the string
  * @endp: A pointer to the end of the parsed string will be placed here
  * @base: The number base to use
  *
  * This function has caveats. Please use kstrtoul instead.
  */
 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
 {
     return simple_strtoull(cp, endp, base);
 }
 EXPORT_SYMBOL(simple_strtoul);
 
 /**
  * simple_strtol - convert a string to a signed long
  * @cp: The start of the string
  * @endp: A pointer to the end of the parsed string will be placed here
  * @base: The number base to use
  *
  * This function has caveats. Please use kstrtol instead.
  */
 long simple_strtol(const char *cp, char **endp, unsigned int base)
 {
     if (*cp == '-')
         return -simple_strtoul(cp + 1, endp, base);
 
     return simple_strtoul(cp, endp, base);
 }
 EXPORT_SYMBOL(simple_strtol);
 
 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
                  unsigned int base)
 {
     /*
      * simple_strntoull() safely handles receiving max_chars==0 in the
      * case cp[0] == '-' && max_chars == 1.
      * If max_chars == 0 we can drop through and pass it to simple_strntoull()
      * and the content of *cp is irrelevant.
      */
     if (*cp == '-' && max_chars > 0)
         return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
 
     return simple_strntoull(cp, max_chars, endp, base);
 }
 
 /**
  * simple_strtoll - convert a string to a signed long long
  * @cp: The start of the string
  * @endp: A pointer to the end of the parsed string will be placed here
  * @base: The number base to use
  *
  * This function has caveats. Please use kstrtoll instead.
  */
 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
 {
     return simple_strntoll(cp, INT_MAX, endp, base);
 }
 EXPORT_SYMBOL(simple_strtoll);
 
 static noinline_for_stack
 int skip_atoi(const char **s)
 {
     int i = 0;
 
     do {
         i = i*10 + *((*s)++) - '0';
     } while (isdigit(**s));
 
     return i;
 }
 
 /*
  * Decimal conversion is by far the most typical, and is used for
  * /proc and /sys data. This directly impacts e.g. top performance
  * with many processes running. We optimize it for speed by emitting
  * two characters at a time, using a 200 byte lookup table. This
  * roughly halves the number of multiplications compared to computing
  * the digits one at a time. Implementation strongly inspired by the
  * previous version, which in turn used ideas described at
  * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
  * from the author, Douglas W. Jones).
  *
  * It turns out there is precisely one 26 bit fixed-point
  * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
  * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
  * range happens to be somewhat larger (x <= 1073741898), but that's
  * irrelevant for our purpose.
  *
  * For dividing a number in the range [10^4, 10^6-1] by 100, we still
  * need a 32x32->64 bit multiply, so we simply use the same constant.
  *
  * For dividing a number in the range [100, 10^4-1] by 100, there are
  * several options. The simplest is (x * 0x147b) >> 19, which is valid
  * for all x <= 43698.
  */
 
 static const u16 decpair[100] = {
 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
     _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
     _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
     _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
     _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
     _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
     _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
     _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
     _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
     _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
     _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
 #undef _
 };
 
 /*
  * This will print a single '0' even if r == 0, since we would
  * immediately jump to out_r where two 0s would be written but only
  * one of them accounted for in buf. This is needed by ip4_string
  * below. All other callers pass a non-zero value of r.
 */
 static noinline_for_stack
 char *put_dec_trunc8(char *buf, unsigned r)
 {
     unsigned q;
 
     /* 1 <= r < 10^8 */
     if (r < 100)
         goto out_r;
 
     /* 100 <= r < 10^8 */
     q = (r * (u64)0x28f5c29) >> 32;
     *((u16 *)buf) = decpair[r - 100*q];
     buf += 2;
 
     /* 1 <= q < 10^6 */
     if (q < 100)
         goto out_q;
 
     /*  100 <= q < 10^6 */
     r = (q * (u64)0x28f5c29) >> 32;
     *((u16 *)buf) = decpair[q - 100*r];
     buf += 2;
 
     /* 1 <= r < 10^4 */
     if (r < 100)
         goto out_r;
 
     /* 100 <= r < 10^4 */
     q = (r * 0x147b) >> 19;
     *((u16 *)buf) = decpair[r - 100*q];
     buf += 2;
 out_q:
     /* 1 <= q < 100 */
     r = q;
 out_r:
     /* 1 <= r < 100 */
     *((u16 *)buf) = decpair[r];
     buf += r < 10 ? 1 : 2;
     return buf;
 }
 
 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
 static noinline_for_stack
 char *put_dec_full8(char *buf, unsigned r)
 {
     unsigned q;
 
     /* 0 <= r < 10^8 */
     q = (r * (u64)0x28f5c29) >> 32;
     *((u16 *)buf) = decpair[r - 100*q];
     buf += 2;
 
     /* 0 <= q < 10^6 */
     r = (q * (u64)0x28f5c29) >> 32;
     *((u16 *)buf) = decpair[q - 100*r];
     buf += 2;
 
     /* 0 <= r < 10^4 */
     q = (r * 0x147b) >> 19;
     *((u16 *)buf) = decpair[r - 100*q];
     buf += 2;
 
     /* 0 <= q < 100 */
     *((u16 *)buf) = decpair[q];
     buf += 2;
     return buf;
 }
 
 static noinline_for_stack
 char *put_dec(char *buf, unsigned long long n)
 {
     if (n >= 100*1000*1000)
         buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
     /* 1 <= n <= 1.6e11 */
     if (n >= 100*1000*1000)
         buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
     /* 1 <= n < 1e8 */
     return put_dec_trunc8(buf, n);
 }
 
 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
 
 static void
 put_dec_full4(char *buf, unsigned r)
 {
     unsigned q;
 
     /* 0 <= r < 10^4 */
     q = (r * 0x147b) >> 19;
     *((u16 *)buf) = decpair[r - 100*q];
     buf += 2;
     /* 0 <= q < 100 */
     *((u16 *)buf) = decpair[q];
 }
 
 /*
  * Call put_dec_full4 on x % 10000, return x / 10000.
  * The approximation x/10000 == (x * 0x346DC5D7) >> 43
  * holds for all x < 1,128,869,999.  The largest value this
  * helper will ever be asked to convert is 1,125,520,955.
  * (second call in the put_dec code, assuming n is all-ones).
  */
 static noinline_for_stack
 unsigned put_dec_helper4(char *buf, unsigned x)
 {
         uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
 
         put_dec_full4(buf, x - q * 10000);
         return q;
 }
 
 /* Based on code by Douglas W. Jones found at
  * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
  * (with permission from the author).
  * Performs no 64-bit division and hence should be fast on 32-bit machines.
  */
 static
 char *put_dec(char *buf, unsigned long long n)
 {
     uint32_t d3, d2, d1, q, h;
 
     if (n < 100*1000*1000)
         return put_dec_trunc8(buf, n);
 
     d1  = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
     h   = (n >> 32);
     d2  = (h      ) & 0xffff;
     d3  = (h >> 16); /* implicit "& 0xffff" */
 
     /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
          = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
     q   = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
     q = put_dec_helper4(buf, q);
 
     q += 7671 * d3 + 9496 * d2 + 6 * d1;
     q = put_dec_helper4(buf+4, q);
 
     q += 4749 * d3 + 42 * d2;
     q = put_dec_helper4(buf+8, q);
 
     q += 281 * d3;
     buf += 12;
     if (q)
         buf = put_dec_trunc8(buf, q);
     else while (buf[-1] == '0')
         --buf;
 
     return buf;
 }
 
 #endif
 
 /*
  * Convert passed number to decimal string.
  * Returns the length of string.  On buffer overflow, returns 0.
  *
  * If speed is not important, use snprintf(). It's easy to read the code.
  */
 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
 {
     /* put_dec requires 2-byte alignment of the buffer. */
     char tmp[sizeof(num) * 3] __aligned(2);
     int idx, len;
 
     /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
     if (num <= 9) {
         tmp[0] = '0' + num;
         len = 1;
     } else {
         len = put_dec(tmp, num) - tmp;
     }
 
     if (len > size || width > size)
         return 0;
 
     if (width > len) {
         width = width - len;
         for (idx = 0; idx < width; idx++)
             buf[idx] = ' ';
     } else {
         width = 0;
     }
 
     for (idx = 0; idx < len; ++idx)
         buf[idx + width] = tmp[len - idx - 1];
 
     return len + width;
 }
 
 #define SIGN    1       /* unsigned/signed, must be 1 */
 #define LEFT    2       /* left justified */
 #define PLUS    4       /* show plus */
 #define SPACE   8       /* space if plus */
 #define ZEROPAD 16      /* pad with zero, must be 16 == '0' - ' ' */
 #define SMALL   32      /* use lowercase in hex (must be 32 == 0x20) */
 #define SPECIAL 64      /* prefix hex with "0x", octal with "0" */
 
 static_assert(SIGN == 1);
 static_assert(ZEROPAD == ('0' - ' '));
 static_assert(SMALL == ('a' ^ 'A'));
 
 enum format_type {
     FORMAT_TYPE_NONE, /* Just a string part */
     FORMAT_TYPE_WIDTH,
     FORMAT_TYPE_PRECISION,
     FORMAT_TYPE_CHAR,
     FORMAT_TYPE_STR,
     FORMAT_TYPE_PTR,
     FORMAT_TYPE_PERCENT_CHAR,
     FORMAT_TYPE_INVALID,
     FORMAT_TYPE_LONG_LONG,
     FORMAT_TYPE_ULONG,
     FORMAT_TYPE_LONG,
     FORMAT_TYPE_UBYTE,
     FORMAT_TYPE_BYTE,
     FORMAT_TYPE_USHORT,
     FORMAT_TYPE_SHORT,
     FORMAT_TYPE_UINT,
     FORMAT_TYPE_INT,
     FORMAT_TYPE_SIZE_T,
     FORMAT_TYPE_PTRDIFF
 };
 
 struct printf_spec {
     unsigned int    type:8;     /* format_type enum */
     signed int  field_width:24; /* width of output field */
     unsigned int    flags:8;    /* flags to number() */
     unsigned int    base:8;     /* number base, 8, 10 or 16 only */
     signed int  precision:16;   /* # of digits/chars */
 } __packed;
 static_assert(sizeof(struct printf_spec) == 8);
 
 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
 #define PRECISION_MAX ((1 << 15) - 1)
 
 static noinline_for_stack
 char *number(char *buf, char *end, unsigned long long num,
          struct printf_spec spec)
 {
     /* put_dec requires 2-byte alignment of the buffer. */
     char tmp[3 * sizeof(num)] __aligned(2);
     char sign;
     char locase;
     int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
     int i;
     bool is_zero = num == 0LL;
     int field_width = spec.field_width;
     int precision = spec.precision;
 
     /* locase = 0 or 0x20. ORing digits or letters with 'locase'
      * produces same digits or (maybe lowercased) letters */
     locase = (spec.flags & SMALL);
     if (spec.flags & LEFT)
         spec.flags &= ~ZEROPAD;
     sign = 0;
     if (spec.flags & SIGN) {
         if ((signed long long)num < 0) {
             sign = '-';
             num = -(signed long long)num;
             field_width--;
         } else if (spec.flags & PLUS) {
             sign = '+';
             field_width--;
         } else if (spec.flags & SPACE) {
             sign = ' ';
             field_width--;
         }
     }
     if (need_pfx) {
         if (spec.base == 16)
             field_width -= 2;
         else if (!is_zero)
             field_width--;
     }
 
     /* generate full string in tmp[], in reverse order */
     i = 0;
     if (num < spec.base)
         tmp[i++] = hex_asc_upper[num] | locase;
     else if (spec.base != 10) { /* 8 or 16 */
         int mask = spec.base - 1;
         int shift = 3;
 
         if (spec.base == 16)
             shift = 4;
         do {
             tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
             num >>= shift;
         } while (num);
     } else { /* base 10 */
         i = put_dec(tmp, num) - tmp;
     }
 
     /* printing 100 using %2d gives "100", not "00" */
     if (i > precision)
         precision = i;
     /* leading space padding */
     field_width -= precision;
     if (!(spec.flags & (ZEROPAD | LEFT))) {
         while (--field_width >= 0) {
             if (buf < end)
                 *buf = ' ';
             ++buf;
         }
     }
     /* sign */
     if (sign) {
         if (buf < end)
             *buf = sign;
         ++buf;
     }
     /* "0x" / "0" prefix */
     if (need_pfx) {
         if (spec.base == 16 || !is_zero) {
             if (buf < end)
                 *buf = '0';
             ++buf;
         }
         if (spec.base == 16) {
             if (buf < end)
                 *buf = ('X' | locase);
             ++buf;
         }
     }
     /* zero or space padding */
     if (!(spec.flags & LEFT)) {
         char c = ' ' + (spec.flags & ZEROPAD);
 
         while (--field_width >= 0) {
             if (buf < end)
                 *buf = c;
             ++buf;
         }
     }
     /* hmm even more zero padding? */
     while (i <= --precision) {
         if (buf < end)
             *buf = '0';
         ++buf;
     }
     /* actual digits of result */
     while (--i >= 0) {
         if (buf < end)
             *buf = tmp[i];
         ++buf;
     }
     /* trailing space padding */
     while (--field_width >= 0) {
         if (buf < end)
             *buf = ' ';
         ++buf;
     }
 
     return buf;
 }
 
 static noinline_for_stack
 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
 {
     struct printf_spec spec;
 
     spec.type = FORMAT_TYPE_PTR;
     spec.field_width = 2 + 2 * size;    /* 0x + hex */
     spec.flags = SPECIAL | SMALL | ZEROPAD;
     spec.base = 16;
     spec.precision = -1;
 
     return number(buf, end, num, spec);
 }
 
 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
 {
     size_t size;
     if (buf >= end) /* nowhere to put anything */
         return;
     size = end - buf;
     if (size <= spaces) {
         memset(buf, ' ', size);
         return;
     }
     if (len) {
         if (len > size - spaces)
             len = size - spaces;
         memmove(buf + spaces, buf, len);
     }
     memset(buf, ' ', spaces);
 }
 
 /*
  * Handle field width padding for a string.
  * @buf: current buffer position
  * @n: length of string
  * @end: end of output buffer
  * @spec: for field width and flags
  * Returns: new buffer position after padding.
  */
 static noinline_for_stack
 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
 {
     unsigned spaces;
 
     if (likely(n >= spec.field_width))
         return buf;
     /* we want to pad the sucker */
     spaces = spec.field_width - n;
     if (!(spec.flags & LEFT)) {
         move_right(buf - n, end, n, spaces);
         return buf + spaces;
     }
     while (spaces--) {
         if (buf < end)
             *buf = ' ';
         ++buf;
     }
     return buf;
 }
 
 /* Handle string from a well known address. */
 static char *string_nocheck(char *buf, char *end, const char *s,
                 struct printf_spec spec)
 {
     int len = 0;
     int lim = spec.precision;
 
     while (lim--) {
         char c = *s++;
         if (!c)
             break;
         if (buf < end)
             *buf = c;
         ++buf;
         ++len;
     }
     return widen_string(buf, len, end, spec);
 }
 
 static char *err_ptr(char *buf, char *end, void *ptr,
              struct printf_spec spec)
 {
     int err = PTR_ERR(ptr);
     const char *sym = errname(err);
 
     if (sym)
         return string_nocheck(buf, end, sym, spec);
 
     /*
      * Somebody passed ERR_PTR(-1234) or some other non-existing
      * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
      * printing it as its decimal representation.
      */
     spec.flags |= SIGN;
     spec.base = 10;
     return number(buf, end, err, spec);
 }
 
 /* Be careful: error messages must fit into the given buffer. */
 static char *error_string(char *buf, char *end, const char *s,
               struct printf_spec spec)
 {
     /*
      * Hard limit to avoid a completely insane messages. It actually
      * works pretty well because most error messages are in
      * the many pointer format modifiers.
      */
     if (spec.precision == -1)
         spec.precision = 2 * sizeof(void *);
 
     return string_nocheck(buf, end, s, spec);
 }
 
 /*
  * Do not call any complex external code here. Nested printk()/vsprintf()
  * might cause infinite loops. Failures might break printk() and would
  * be hard to debug.
  */
 static const char *check_pointer_msg(const void *ptr)
 {
     if (!ptr)
         return "(null)";
 
     if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
         return "(efault)";
 
     return NULL;
 }
 
 static int check_pointer(char **buf, char *end, const void *ptr,
              struct printf_spec spec)
 {
     const char *err_msg;
 
     err_msg = check_pointer_msg(ptr);
     if (err_msg) {
         *buf = error_string(*buf, end, err_msg, spec);
         return -EFAULT;
     }
 
     return 0;
 }
 
 static noinline_for_stack
 char *string(char *buf, char *end, const char *s,
          struct printf_spec spec)
 {
     if (check_pointer(&buf, end, s, spec))
         return buf;
 
     return string_nocheck(buf, end, s, spec);
 }
 
 static char *pointer_string(char *buf, char *end,
                 const void *ptr,
                 struct printf_spec spec)
 {
     spec.base = 16;
     spec.flags |= SMALL;
     if (spec.field_width == -1) {
         spec.field_width = 2 * sizeof(ptr);
         spec.flags |= ZEROPAD;
     }
 
     return number(buf, end, (unsigned long int)ptr, spec);
 }
 
 /* Make pointers available for printing early in the boot sequence. */
 static int debug_boot_weak_hash __ro_after_init;
 
 static int __init debug_boot_weak_hash_enable(char *str)
 {
     debug_boot_weak_hash = 1;
     pr_info("debug_boot_weak_hash enabled\n");
     return 0;
 }
 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
 
 static DEFINE_STATIC_KEY_FALSE(filled_random_ptr_key);
 
 static void enable_ptr_key_workfn(struct work_struct *work)
 {
     static_branch_enable(&filled_random_ptr_key);
 }
 
 /* Maps a pointer to a 32 bit unique identifier. */
 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 {
     static siphash_key_t ptr_key __read_mostly;
     unsigned long hashval;
 
     if (!static_branch_likely(&filled_random_ptr_key)) {
         static bool filled = false;
         static DEFINE_SPINLOCK(filling);
         static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
         unsigned long flags;
 
         if (!system_unbound_wq || !rng_is_initialized() ||
             !spin_trylock_irqsave(&filling, flags))
             return -EAGAIN;
 
         if (!filled) {
             get_random_bytes(&ptr_key, sizeof(ptr_key));
             queue_work(system_unbound_wq, &enable_ptr_key_work);
             filled = true;
         }
         spin_unlock_irqrestore(&filling, flags);
     }
 
 
 #ifdef CONFIG_64BIT
     hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
     /*
      * Mask off the first 32 bits, this makes explicit that we have
      * modified the address (and 32 bits is plenty for a unique ID).
      */
     hashval = hashval & 0xffffffff;
 #else
     hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
 #endif
     *hashval_out = hashval;
     return 0;
 }
 
 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 {
     return __ptr_to_hashval(ptr, hashval_out);
 }
 
 static char *ptr_to_id(char *buf, char *end, const void *ptr,
                struct printf_spec spec)
 {
     const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
     unsigned long hashval;
     int ret;
 
     /*
      * Print the real pointer value for NULL and error pointers,
      * as they are not actual addresses.
      */
     if (IS_ERR_OR_NULL(ptr))
         return pointer_string(buf, end, ptr, spec);
 
     /* When debugging early boot use non-cryptographically secure hash. */
     if (unlikely(debug_boot_weak_hash)) {
         hashval = hash_long((unsigned long)ptr, 32);
         return pointer_string(buf, end, (const void *)hashval, spec);
     }
 
     ret = __ptr_to_hashval(ptr, &hashval);
     if (ret) {
         spec.field_width = 2 * sizeof(ptr);
         /* string length must be less than default_width */
         return error_string(buf, end, str, spec);
     }
 
     return pointer_string(buf, end, (const void *)hashval, spec);
 }
 
 static char *default_pointer(char *buf, char *end, const void *ptr,
                  struct printf_spec spec)
 {
     /*
      * default is to _not_ leak addresses, so hash before printing,
      * unless no_hash_pointers is specified on the command line.
      */
     if (unlikely(no_hash_pointers))
         return pointer_string(buf, end, ptr, spec);
 
     return ptr_to_id(buf, end, ptr, spec);
 }
 
 int kptr_restrict __read_mostly;
 
 static noinline_for_stack
 char *restricted_pointer(char *buf, char *end, const void *ptr,
              struct printf_spec spec)
 {
     switch (kptr_restrict) {
     case 0:
         /* Handle as %p, hash and do _not_ leak addresses. */
         return default_pointer(buf, end, ptr, spec);
     case 1: {
         const struct cred *cred;
 
         /*
          * kptr_restrict==1 cannot be used in IRQ context
          * because its test for CAP_SYSLOG would be meaningless.
          */
         if (in_irq() || in_serving_softirq() || in_nmi()) {
             if (spec.field_width == -1)
                 spec.field_width = 2 * sizeof(ptr);
             return error_string(buf, end, "pK-error", spec);
         }
 
         /*
          * Only print the real pointer value if the current
          * process has CAP_SYSLOG and is running with the
          * same credentials it started with. This is because
          * access to files is checked at open() time, but %pK
          * checks permission at read() time. We don't want to
          * leak pointer values if a binary opens a file using
          * %pK and then elevates privileges before reading it.
          */
         cred = current_cred();
         if (!has_capability_noaudit(current, CAP_SYSLOG) ||
             !uid_eq(cred->euid, cred->uid) ||
             !gid_eq(cred->egid, cred->gid))
             ptr = NULL;
         break;
     }
     case 2:
     default:
         /* Always print 0's for %pK */
         ptr = NULL;
         break;
     }
 
     return pointer_string(buf, end, ptr, spec);
 }
 
 static noinline_for_stack
 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
           const char *fmt)
 {
     const char *array[4], *s;
     const struct dentry *p;
     int depth;
     int i, n;
 
     switch (fmt[1]) {
         case '2': case '3': case '4':
             depth = fmt[1] - '0';
             break;
         default:
             depth = 1;
     }
 
     rcu_read_lock();
     for (i = 0; i < depth; i++, d = p) {
         if (check_pointer(&buf, end, d, spec)) {
             rcu_read_unlock();
             return buf;
         }
 
         p = READ_ONCE(d->d_parent);
         array[i] = READ_ONCE(d->d_name.name);
         if (p == d) {
             if (i)
                 array[i] = "";
             i++;
             break;
         }
     }
     s = array[--i];
     for (n = 0; n != spec.precision; n++, buf++) {
         char c = *s++;
         if (!c) {
             if (!i)
                 break;
             c = '/';
             s = array[--i];
         }
         if (buf < end)
             *buf = c;
     }
     rcu_read_unlock();
     return widen_string(buf, n, end, spec);
 }
 
 static noinline_for_stack
 char *file_dentry_name(char *buf, char *end, const struct file *f,
             struct printf_spec spec, const char *fmt)
 {
     if (check_pointer(&buf, end, f, spec))
         return buf;
 
     return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
 }
 #ifdef CONFIG_BLOCK
 static noinline_for_stack
 char *bdev_name(char *buf, char *end, struct block_device *bdev,
         struct printf_spec spec, const char *fmt)
 {
     struct gendisk *hd;
 
     if (check_pointer(&buf, end, bdev, spec))
         return buf;
 
     hd = bdev->bd_disk;
     buf = string(buf, end, hd->disk_name, spec);
     if (bdev->bd_partno) {
         if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
             if (buf < end)
                 *buf = 'p';
             buf++;
         }
         buf = number(buf, end, bdev->bd_partno, spec);
     }
     return buf;
 }
 #endif
 
 static noinline_for_stack
 char *symbol_string(char *buf, char *end, void *ptr,
             struct printf_spec spec, const char *fmt)
 {
     unsigned long value;
 #ifdef CONFIG_KALLSYMS
     char sym[KSYM_SYMBOL_LEN];
 #endif
 
     if (fmt[1] == 'R')
         ptr = __builtin_extract_return_addr(ptr);
     value = (unsigned long)ptr;
 
 #ifdef CONFIG_KALLSYMS
     if (*fmt == 'B' && fmt[1] == 'b')
         sprint_backtrace_build_id(sym, value);
     else if (*fmt == 'B')
         sprint_backtrace(sym, value);
     else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b')))
         sprint_symbol_build_id(sym, value);
     else if (*fmt != 's')
         sprint_symbol(sym, value);
     else
         sprint_symbol_no_offset(sym, value);
 
     return string_nocheck(buf, end, sym, spec);
 #else
     return special_hex_number(buf, end, value, sizeof(void *));
 #endif
 }
 
 static const struct printf_spec default_str_spec = {
     .field_width = -1,
     .precision = -1,
 };
 
 static const struct printf_spec default_flag_spec = {
     .base = 16,
     .precision = -1,
     .flags = SPECIAL | SMALL,
 };
 
 static const struct printf_spec default_dec_spec = {
     .base = 10,
     .precision = -1,
 };
 
 static const struct printf_spec default_dec02_spec = {
     .base = 10,
     .field_width = 2,
     .precision = -1,
     .flags = ZEROPAD,
 };
 
 static const struct printf_spec default_dec04_spec = {
     .base = 10,
     .field_width = 4,
     .precision = -1,
     .flags = ZEROPAD,
 };
 
 static noinline_for_stack
 char *resource_string(char *buf, char *end, struct resource *res,
               struct printf_spec spec, const char *fmt)
 {
 #ifndef IO_RSRC_PRINTK_SIZE
 #define IO_RSRC_PRINTK_SIZE 6
 #endif
 
 #ifndef MEM_RSRC_PRINTK_SIZE
 #define MEM_RSRC_PRINTK_SIZE    10
 #endif
     static const struct printf_spec io_spec = {
         .base = 16,
         .field_width = IO_RSRC_PRINTK_SIZE,
         .precision = -1,
         .flags = SPECIAL | SMALL | ZEROPAD,
     };
     static const struct printf_spec mem_spec = {
         .base = 16,
         .field_width = MEM_RSRC_PRINTK_SIZE,
         .precision = -1,
         .flags = SPECIAL | SMALL | ZEROPAD,
     };
     static const struct printf_spec bus_spec = {
         .base = 16,
         .field_width = 2,
         .precision = -1,
         .flags = SMALL | ZEROPAD,
     };
     static const struct printf_spec str_spec = {
         .field_width = -1,
         .precision = 10,
         .flags = LEFT,
     };
 
     /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
      * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
 #define RSRC_BUF_SIZE       ((2 * sizeof(resource_size_t)) + 4)
 #define FLAG_BUF_SIZE       (2 * sizeof(res->flags))
 #define DECODED_BUF_SIZE    sizeof("[mem - 64bit pref window disabled]")
 #define RAW_BUF_SIZE        sizeof("[mem - flags 0x]")
     char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
              2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
 
     char *p = sym, *pend = sym + sizeof(sym);
     int decode = (fmt[0] == 'R') ? 1 : 0;
     const struct printf_spec *specp;
 
     if (check_pointer(&buf, end, res, spec))
         return buf;
 
     *p++ = '[';
     if (res->flags & IORESOURCE_IO) {
         p = string_nocheck(p, pend, "io  ", str_spec);
         specp = &io_spec;
     } else if (res->flags & IORESOURCE_MEM) {
         p = string_nocheck(p, pend, "mem ", str_spec);
         specp = &mem_spec;
     } else if (res->flags & IORESOURCE_IRQ) {
         p = string_nocheck(p, pend, "irq ", str_spec);
         specp = &default_dec_spec;
     } else if (res->flags & IORESOURCE_DMA) {
         p = string_nocheck(p, pend, "dma ", str_spec);
         specp = &default_dec_spec;
     } else if (res->flags & IORESOURCE_BUS) {
         p = string_nocheck(p, pend, "bus ", str_spec);
         specp = &bus_spec;
     } else {
         p = string_nocheck(p, pend, "??? ", str_spec);
         specp = &mem_spec;
         decode = 0;
     }
     if (decode && res->flags & IORESOURCE_UNSET) {
         p = string_nocheck(p, pend, "size ", str_spec);
         p = number(p, pend, resource_size(res), *specp);
     } else {
         p = number(p, pend, res->start, *specp);
         if (res->start != res->end) {
             *p++ = '-';
             p = number(p, pend, res->end, *specp);
         }
     }
     if (decode) {
         if (res->flags & IORESOURCE_MEM_64)
             p = string_nocheck(p, pend, " 64bit", str_spec);
         if (res->flags & IORESOURCE_PREFETCH)
             p = string_nocheck(p, pend, " pref", str_spec);
         if (res->flags & IORESOURCE_WINDOW)
             p = string_nocheck(p, pend, " window", str_spec);
         if (res->flags & IORESOURCE_DISABLED)
             p = string_nocheck(p, pend, " disabled", str_spec);
     } else {
         p = string_nocheck(p, pend, " flags ", str_spec);
         p = number(p, pend, res->flags, default_flag_spec);
     }
     *p++ = ']';
     *p = '\0';
 
     return string_nocheck(buf, end, sym, spec);
 }
 
 static noinline_for_stack
 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
          const char *fmt)
 {
     int i, len = 1;     /* if we pass '%ph[CDN]', field width remains
                    negative value, fallback to the default */
     char separator;
 
     if (spec.field_width == 0)
         /* nothing to print */
         return buf;
 
     if (check_pointer(&buf, end, addr, spec))
         return buf;
 
     switch (fmt[1]) {
     case 'C':
         separator = ':';
         break;
     case 'D':
         separator = '-';
         break;
     case 'N':
         separator = 0;
         break;
     default:
         separator = ' ';
         break;
     }
 
     if (spec.field_width > 0)
         len = min_t(int, spec.field_width, 64);
 
     for (i = 0; i < len; ++i) {
         if (buf < end)
             *buf = hex_asc_hi(addr[i]);
         ++buf;
         if (buf < end)
             *buf = hex_asc_lo(addr[i]);
         ++buf;
 
         if (separator && i != len - 1) {
             if (buf < end)
                 *buf = separator;
             ++buf;
         }
     }
 
     return buf;
 }
 
 static noinline_for_stack
 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
             struct printf_spec spec, const char *fmt)
 {
     const int CHUNKSZ = 32;
     int nr_bits = max_t(int, spec.field_width, 0);
     int i, chunksz;
     bool first = true;
 
     if (check_pointer(&buf, end, bitmap, spec))
         return buf;
 
     /* reused to print numbers */
     spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
 
     chunksz = nr_bits & (CHUNKSZ - 1);
     if (chunksz == 0)
         chunksz = CHUNKSZ;
 
     i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
     for (; i >= 0; i -= CHUNKSZ) {
         u32 chunkmask, val;
         int word, bit;
 
         chunkmask = ((1ULL << chunksz) - 1);
         word = i / BITS_PER_LONG;
         bit = i % BITS_PER_LONG;
         val = (bitmap[word] >> bit) & chunkmask;
 
         if (!first) {
             if (buf < end)
                 *buf = ',';
             buf++;
         }
         first = false;
 
         spec.field_width = DIV_ROUND_UP(chunksz, 4);
         buf = number(buf, end, val, spec);
 
         chunksz = CHUNKSZ;
     }
     return buf;
 }
 
 static noinline_for_stack
 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
              struct printf_spec spec, const char *fmt)
 {
     int nr_bits = max_t(int, spec.field_width, 0);
     bool first = true;
     int rbot, rtop;
 
     if (check_pointer(&buf, end, bitmap, spec))
         return buf;
 
     for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) {
         if (!first) {
             if (buf < end)
                 *buf = ',';
             buf++;
         }
         first = false;
 
         buf = number(buf, end, rbot, default_dec_spec);
         if (rtop == rbot + 1)
             continue;
 
         if (buf < end)
             *buf = '-';
         buf = number(++buf, end, rtop - 1, default_dec_spec);
     }
     return buf;
 }
 
 static noinline_for_stack
 char *mac_address_string(char *buf, char *end, u8 *addr,
              struct printf_spec spec, const char *fmt)
 {
     char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
     char *p = mac_addr;
     int i;
     char separator;
     bool reversed = false;
 
     if (check_pointer(&buf, end, addr, spec))
         return buf;
 
     switch (fmt[1]) {
     case 'F':
         separator = '-';
         break;
 
     case 'R':
         reversed = true;
         fallthrough;
 
     default:
         separator = ':';
         break;
     }
 
     for (i = 0; i < 6; i++) {
         if (reversed)
             p = hex_byte_pack(p, addr[5 - i]);
         else
             p = hex_byte_pack(p, addr[i]);
 
         if (fmt[0] == 'M' && i != 5)
             *p++ = separator;
     }
     *p = '\0';
 
     return string_nocheck(buf, end, mac_addr, spec);
 }
 
 static noinline_for_stack
 char *ip4_string(char *p, const u8 *addr, const char *fmt)
 {
     int i;
     bool leading_zeros = (fmt[0] == 'i');
     int index;
     int step;
 
     switch (fmt[2]) {
     case 'h':
 #ifdef __BIG_ENDIAN
         index = 0;
         step = 1;
 #else
         index = 3;
         step = -1;
 #endif
         break;
     case 'l':
         index = 3;
         step = -1;
         break;
     case 'n':
     case 'b':
     default:
         index = 0;
         step = 1;
         break;
     }
     for (i = 0; i < 4; i++) {
         char temp[4] __aligned(2);  /* hold each IP quad in reverse order */
         int digits = put_dec_trunc8(temp, addr[index]) - temp;
         if (leading_zeros) {
             if (digits < 3)
                 *p++ = '0';
             if (digits < 2)
                 *p++ = '0';
         }
         /* reverse the digits in the quad */
         while (digits--)
             *p++ = temp[digits];
         if (i < 3)
             *p++ = '.';
         index += step;
     }
     *p = '\0';
 
     return p;
 }
 
 static noinline_for_stack
 char *ip6_compressed_string(char *p, const char *addr)
 {
     int i, j, range;
     unsigned char zerolength[8];
     int longest = 1;
     int colonpos = -1;
     u16 word;
     u8 hi, lo;
     bool needcolon = false;
     bool useIPv4;
     struct in6_addr in6;
 
     memcpy(&in6, addr, sizeof(struct in6_addr));
 
     useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
 
     memset(zerolength, 0, sizeof(zerolength));
 
     if (useIPv4)
         range = 6;
     else
         range = 8;
 
     /* find position of longest 0 run */
     for (i = 0; i < range; i++) {
         for (j = i; j < range; j++) {
             if (in6.s6_addr16[j] != 0)
                 break;
             zerolength[i]++;
         }
     }
     for (i = 0; i < range; i++) {
         if (zerolength[i] > longest) {
             longest = zerolength[i];
             colonpos = i;
         }
     }
     if (longest == 1)       /* don't compress a single 0 */
         colonpos = -1;
 
     /* emit address */
     for (i = 0; i < range; i++) {
         if (i == colonpos) {
             if (needcolon || i == 0)
                 *p++ = ':';
             *p++ = ':';
             needcolon = false;
             i += longest - 1;
             continue;
         }
         if (needcolon) {
             *p++ = ':';
             needcolon = false;
         }
         /* hex u16 without leading 0s */
         word = ntohs(in6.s6_addr16[i]);
         hi = word >> 8;
         lo = word & 0xff;
         if (hi) {
             if (hi > 0x0f)
                 p = hex_byte_pack(p, hi);
             else
                 *p++ = hex_asc_lo(hi);
             p = hex_byte_pack(p, lo);
         }
         else if (lo > 0x0f)
             p = hex_byte_pack(p, lo);
         else
             *p++ = hex_asc_lo(lo);
         needcolon = true;
     }
 
     if (useIPv4) {
         if (needcolon)
             *p++ = ':';
         p = ip4_string(p, &in6.s6_addr[12], "I4");
     }
     *p = '\0';
 
     return p;
 }
 
 static noinline_for_stack
 char *ip6_string(char *p, const char *addr, const char *fmt)
 {
     int i;
 
     for (i = 0; i < 8; i++) {
         p = hex_byte_pack(p, *addr++);
         p = hex_byte_pack(p, *addr++);
         if (fmt[0] == 'I' && i != 7)
             *p++ = ':';
     }
     *p = '\0';
 
     return p;
 }
 
 static noinline_for_stack
 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
               struct printf_spec spec, const char *fmt)
 {
     char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
 
     if (fmt[0] == 'I' && fmt[2] == 'c')
         ip6_compressed_string(ip6_addr, addr);
     else
         ip6_string(ip6_addr, addr, fmt);
 
     return string_nocheck(buf, end, ip6_addr, spec);
 }
 
 static noinline_for_stack
 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
               struct printf_spec spec, const char *fmt)
 {
     char ip4_addr[sizeof("255.255.255.255")];
 
     ip4_string(ip4_addr, addr, fmt);
 
     return string_nocheck(buf, end, ip4_addr, spec);
 }
 
 static noinline_for_stack
 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
              struct printf_spec spec, const char *fmt)
 {
     bool have_p = false, have_s = false, have_f = false, have_c = false;
     char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
               sizeof(":12345") + sizeof("/123456789") +
               sizeof("%1234567890")];
     char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
     const u8 *addr = (const u8 *) &sa->sin6_addr;
     char fmt6[2] = { fmt[0], '6' };
     u8 off = 0;
 
     fmt++;
     while (isalpha(*++fmt)) {
         switch (*fmt) {
         case 'p':
             have_p = true;
             break;
         case 'f':
             have_f = true;
             break;
         case 's':
             have_s = true;
             break;
         case 'c':
             have_c = true;
             break;
         }
     }
 
     if (have_p || have_s || have_f) {
         *p = '[';
         off = 1;
     }
 
     if (fmt6[0] == 'I' && have_c)
         p = ip6_compressed_string(ip6_addr + off, addr);
     else
         p = ip6_string(ip6_addr + off, addr, fmt6);
 
     if (have_p || have_s || have_f)
         *p++ = ']';
 
     if (have_p) {
         *p++ = ':';
         p = number(p, pend, ntohs(sa->sin6_port), spec);
     }
     if (have_f) {
         *p++ = '/';
         p = number(p, pend, ntohl(sa->sin6_flowinfo &
                       IPV6_FLOWINFO_MASK), spec);
     }
     if (have_s) {
         *p++ = '%';
         p = number(p, pend, sa->sin6_scope_id, spec);
     }
     *p = '\0';
 
     return string_nocheck(buf, end, ip6_addr, spec);
 }
 
 static noinline_for_stack
 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
              struct printf_spec spec, const char *fmt)
 {
     bool have_p = false;
     char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
     char *pend = ip4_addr + sizeof(ip4_addr);
     const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
     char fmt4[3] = { fmt[0], '4', 0 };
 
     fmt++;
     while (isalpha(*++fmt)) {
         switch (*fmt) {
         case 'p':
             have_p = true;
             break;
         case 'h':
         case 'l':
         case 'n':
         case 'b':
             fmt4[2] = *fmt;
             break;
         }
     }
 
     p = ip4_string(ip4_addr, addr, fmt4);
     if (have_p) {
         *p++ = ':';
         p = number(p, pend, ntohs(sa->sin_port), spec);
     }
     *p = '\0';
 
     return string_nocheck(buf, end, ip4_addr, spec);
 }
 
 static noinline_for_stack
 char *ip_addr_string(char *buf, char *end, const void *ptr,
              struct printf_spec spec, const char *fmt)
 {
     char *err_fmt_msg;
 
     if (check_pointer(&buf, end, ptr, spec))
         return buf;
 
     switch (fmt[1]) {
     case '6':
         return ip6_addr_string(buf, end, ptr, spec, fmt);
     case '4':
         return ip4_addr_string(buf, end, ptr, spec, fmt);
     case 'S': {
         const union {
             struct sockaddr     raw;
             struct sockaddr_in  v4;
             struct sockaddr_in6 v6;
         } *sa = ptr;
 
         switch (sa->raw.sa_family) {
         case AF_INET:
             return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
         case AF_INET6:
             return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
         default:
             return error_string(buf, end, "(einval)", spec);
         }}
     }
 
     err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
     return error_string(buf, end, err_fmt_msg, spec);
 }
 
 static noinline_for_stack
 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
              const char *fmt)
 {
     bool found = true;
     int count = 1;
     unsigned int flags = 0;
     int len;
 
     if (spec.field_width == 0)
         return buf;             /* nothing to print */
 
     if (check_pointer(&buf, end, addr, spec))
         return buf;
 
     do {
         switch (fmt[count++]) {
         case 'a':
             flags |= ESCAPE_ANY;
             break;
         case 'c':
             flags |= ESCAPE_SPECIAL;
             break;
         case 'h':
             flags |= ESCAPE_HEX;
             break;
         case 'n':
             flags |= ESCAPE_NULL;
             break;
         case 'o':
             flags |= ESCAPE_OCTAL;
             break;
         case 'p':
             flags |= ESCAPE_NP;
             break;
         case 's':
             flags |= ESCAPE_SPACE;
             break;
         default:
             found = false;
             break;
         }
     } while (found);
 
     if (!flags)
         flags = ESCAPE_ANY_NP;
 
     len = spec.field_width < 0 ? 1 : spec.field_width;
 
     /*
      * string_escape_mem() writes as many characters as it can to
      * the given buffer, and returns the total size of the output
      * had the buffer been big enough.
      */
     buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
 
     return buf;
 }
 
 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
                struct printf_spec spec, const char *fmt)
 {
     va_list va;
 
     if (check_pointer(&buf, end, va_fmt, spec))
         return buf;
 
     va_copy(va, *va_fmt->va);
     buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
     va_end(va);
 
     return buf;
 }
 
 static noinline_for_stack
 char *uuid_string(char *buf, char *end, const u8 *addr,
           struct printf_spec spec, const char *fmt)
 {
     char uuid[UUID_STRING_LEN + 1];
     char *p = uuid;
     int i;
     const u8 *index = uuid_index;
     bool uc = false;
 
     if (check_pointer(&buf, end, addr, spec))
         return buf;
 
     switch (*(++fmt)) {
     case 'L':
         uc = true;
         fallthrough;
     case 'l':
         index = guid_index;
         break;
     case 'B':
         uc = true;
         break;
     }
 
     for (i = 0; i < 16; i++) {
         if (uc)
             p = hex_byte_pack_upper(p, addr[index[i]]);
         else
             p = hex_byte_pack(p, addr[index[i]]);
         switch (i) {
         case 3:
         case 5:
         case 7:
         case 9:
             *p++ = '-';
             break;
         }
     }
 
     *p = 0;
 
     return string_nocheck(buf, end, uuid, spec);
 }
 
 static noinline_for_stack
 char *netdev_bits(char *buf, char *end, const void *addr,
           struct printf_spec spec,  const char *fmt)
 {
     unsigned long long num;
     int size;
 
     if (check_pointer(&buf, end, addr, spec))
         return buf;
 
     switch (fmt[1]) {
     case 'F':
         num = *(const netdev_features_t *)addr;
         size = sizeof(netdev_features_t);
         break;
     default:
         return error_string(buf, end, "(%pN?)", spec);
     }
 
     return special_hex_number(buf, end, num, size);
 }
 
 static noinline_for_stack
 char *fourcc_string(char *buf, char *end, const u32 *fourcc,
             struct printf_spec spec, const char *fmt)
 {
     char output[sizeof("0123 little-endian (0x01234567)")];
     char *p = output;
     unsigned int i;
     u32 orig, val;
 
     if (fmt[1] != 'c' || fmt[2] != 'c')
         return error_string(buf, end, "(%p4?)", spec);
 
     if (check_pointer(&buf, end, fourcc, spec))
         return buf;
 
     orig = get_unaligned(fourcc);
     val = orig & ~BIT(31);
 
     for (i = 0; i < sizeof(u32); i++) {
         unsigned char c = val >> (i * 8);
 
         /* Print non-control ASCII characters as-is, dot otherwise */
         *p++ = isascii(c) && isprint(c) ? c : '.';
     }
 
     *p++ = ' ';
     strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian");
     p += strlen(p);
 
     *p++ = ' ';
     *p++ = '(';
     p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32));
     *p++ = ')';
     *p = '\0';
 
     return string(buf, end, output, spec);
 }
 
 static noinline_for_stack
 char *address_val(char *buf, char *end, const void *addr,
           struct printf_spec spec, const char *fmt)
 {
     unsigned long long num;
     int size;
 
     if (check_pointer(&buf, end, addr, spec))
         return buf;
 
     switch (fmt[1]) {
     case 'd':
         num = *(const dma_addr_t *)addr;
         size = sizeof(dma_addr_t);
         break;
     case 'p':
     default:
         num = *(const phys_addr_t *)addr;
         size = sizeof(phys_addr_t);
         break;
     }
 
     return special_hex_number(buf, end, num, size);
 }
 
 static noinline_for_stack
 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
 {
     int year = tm->tm_year + (r ? 0 : 1900);
     int mon = tm->tm_mon + (r ? 0 : 1);
 
     buf = number(buf, end, year, default_dec04_spec);
     if (buf < end)
         *buf = '-';
     buf++;
 
     buf = number(buf, end, mon, default_dec02_spec);
     if (buf < end)
         *buf = '-';
     buf++;
 
     return number(buf, end, tm->tm_mday, default_dec02_spec);
 }
 
 static noinline_for_stack
 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
 {
     buf = number(buf, end, tm->tm_hour, default_dec02_spec);
     if (buf < end)
         *buf = ':';
     buf++;
 
     buf = number(buf, end, tm->tm_min, default_dec02_spec);
     if (buf < end)
         *buf = ':';
     buf++;
 
     return number(buf, end, tm->tm_sec, default_dec02_spec);
 }
 
 static noinline_for_stack
 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
           struct printf_spec spec, const char *fmt)
 {
     bool have_t = true, have_d = true;
     bool raw = false, iso8601_separator = true;
     bool found = true;
     int count = 2;
 
     if (check_pointer(&buf, end, tm, spec))
         return buf;
 
     switch (fmt[count]) {
     case 'd':
         have_t = false;
         count++;
         break;
     case 't':
         have_d = false;
         count++;
         break;
     }
 
     do {
         switch (fmt[count++]) {
         case 'r':
             raw = true;
             break;
         case 's':
             iso8601_separator = false;
             break;
         default:
             found = false;
             break;
         }
     } while (found);
 
     if (have_d)
         buf = date_str(buf, end, tm, raw);
     if (have_d && have_t) {
         if (buf < end)
             *buf = iso8601_separator ? 'T' : ' ';
         buf++;
     }
     if (have_t)
         buf = time_str(buf, end, tm, raw);
 
     return buf;
 }
 
 static noinline_for_stack
 char *time64_str(char *buf, char *end, const time64_t time,
          struct printf_spec spec, const char *fmt)
 {
     struct rtc_time rtc_time;
     struct tm tm;
 
     time64_to_tm(time, 0, &tm);
 
     rtc_time.tm_sec = tm.tm_sec;
     rtc_time.tm_min = tm.tm_min;
     rtc_time.tm_hour = tm.tm_hour;
     rtc_time.tm_mday = tm.tm_mday;
     rtc_time.tm_mon = tm.tm_mon;
     rtc_time.tm_year = tm.tm_year;
     rtc_time.tm_wday = tm.tm_wday;
     rtc_time.tm_yday = tm.tm_yday;
 
     rtc_time.tm_isdst = 0;
 
     return rtc_str(buf, end, &rtc_time, spec, fmt);
 }
 
 static noinline_for_stack
 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
             const char *fmt)
 {
     switch (fmt[1]) {
     case 'R':
         return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
     case 'T':
         return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
     default:
         return error_string(buf, end, "(%pt?)", spec);
     }
 }
 
 static noinline_for_stack
 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
         const char *fmt)
 {
     if (!IS_ENABLED(CONFIG_HAVE_CLK))
         return error_string(buf, end, "(%pC?)", spec);
 
     if (check_pointer(&buf, end, clk, spec))
         return buf;
 
     switch (fmt[1]) {
     case 'n':
     default:
 #ifdef CONFIG_COMMON_CLK
         return string(buf, end, __clk_get_name(clk), spec);
 #else
         return ptr_to_id(buf, end, clk, spec);
 #endif
     }
 }
 
 static
 char *format_flags(char *buf, char *end, unsigned long flags,
                     const struct trace_print_flags *names)
 {
     unsigned long mask;
 
     for ( ; flags && names->name; names++) {
         mask = names->mask;
         if ((flags & mask) != mask)
             continue;
 
         buf = string(buf, end, names->name, default_str_spec);
 
         flags &= ~mask;
         if (flags) {
             if (buf < end)
                 *buf = '|';
             buf++;
         }
     }
 
     if (flags)
         buf = number(buf, end, flags, default_flag_spec);
 
     return buf;
 }
 
 struct page_flags_fields {
     int width;
     int shift;
     int mask;
     const struct printf_spec *spec;
     const char *name;
 };
 
 static const struct page_flags_fields pff[] = {
     {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
      &default_dec_spec, "section"},
     {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
      &default_dec_spec, "node"},
     {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
      &default_dec_spec, "zone"},
     {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
      &default_flag_spec, "lastcpupid"},
     {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
      &default_flag_spec, "kasantag"},
 };
 
 static
 char *format_page_flags(char *buf, char *end, unsigned long flags)
 {
     unsigned long main_flags = flags & PAGEFLAGS_MASK;
     bool append = false;
     int i;
 
     buf = number(buf, end, flags, default_flag_spec);
     if (buf < end)
         *buf = '(';
     buf++;
 
     /* Page flags from the main area. */
     if (main_flags) {
         buf = format_flags(buf, end, main_flags, pageflag_names);
         append = true;
     }
 
     /* Page flags from the fields area */
     for (i = 0; i < ARRAY_SIZE(pff); i++) {
         /* Skip undefined fields. */
         if (!pff[i].width)
             continue;
 
         /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
         if (append) {
             if (buf < end)
                 *buf = '|';
             buf++;
         }
 
         buf = string(buf, end, pff[i].name, default_str_spec);
         if (buf < end)
             *buf = '=';
         buf++;
         buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask,
                  *pff[i].spec);
 
         append = true;
     }
     if (buf < end)
         *buf = ')';
     buf++;
 
     return buf;
 }
 
 static noinline_for_stack
 char *flags_string(char *buf, char *end, void *flags_ptr,
            struct printf_spec spec, const char *fmt)
 {
     unsigned long flags;
     const struct trace_print_flags *names;
 
     if (check_pointer(&buf, end, flags_ptr, spec))
         return buf;
 
     switch (fmt[1]) {
     case 'p':
         return format_page_flags(buf, end, *(unsigned long *)flags_ptr);
     case 'v':
         flags = *(unsigned long *)flags_ptr;
         names = vmaflag_names;
         break;
     case 'g':
         flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
         names = gfpflag_names;
         break;
     default:
         return error_string(buf, end, "(%pG?)", spec);
     }
 
     return format_flags(buf, end, flags, names);
 }
 
 static noinline_for_stack
 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
                   char *end)
 {
     int depth;
 
     /* Loop starting from the root node to the current node. */
     for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
         struct fwnode_handle *__fwnode =
             fwnode_get_nth_parent(fwnode, depth);
 
         buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
                  default_str_spec);
         buf = string(buf, end, fwnode_get_name(__fwnode),
                  default_str_spec);
 
         fwnode_handle_put(__fwnode);
     }
 
     return buf;
 }
 
 static noinline_for_stack
 char *device_node_string(char *buf, char *end, struct device_node *dn,
              struct printf_spec spec, const char *fmt)
 {
     char tbuf[sizeof("xxxx") + 1];
     const char *p;
     int ret;
     char *buf_start = buf;
     struct property *prop;
     bool has_mult, pass;
 
     struct printf_spec str_spec = spec;
     str_spec.field_width = -1;
 
     if (fmt[0] != 'F')
         return error_string(buf, end, "(%pO?)", spec);
 
     if (!IS_ENABLED(CONFIG_OF))
         return error_string(buf, end, "(%pOF?)", spec);
 
     if (check_pointer(&buf, end, dn, spec))
         return buf;
 
     /* simple case without anything any more format specifiers */
     fmt++;
     if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
         fmt = "f";
 
     for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
         int precision;
         if (pass) {
             if (buf < end)
                 *buf = ':';
             buf++;
         }
 
         switch (*fmt) {
         case 'f':   /* full_name */
             buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
                               end);
             break;
         case 'n':   /* name */
             p = fwnode_get_name(of_fwnode_handle(dn));
             precision = str_spec.precision;
             str_spec.precision = strchrnul(p, '@') - p;
             buf = string(buf, end, p, str_spec);
             str_spec.precision = precision;
             break;
         case 'p':   /* phandle */
             buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
             break;
         case 'P':   /* path-spec */
             p = fwnode_get_name(of_fwnode_handle(dn));
             if (!p[1])
                 p = "/";
             buf = string(buf, end, p, str_spec);
             break;
         case 'F':   /* flags */
             tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
             tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
             tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
             tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
             tbuf[4] = 0;
             buf = string_nocheck(buf, end, tbuf, str_spec);
             break;
         case 'c':   /* major compatible string */
             ret = of_property_read_string(dn, "compatible", &p);
             if (!ret)
                 buf = string(buf, end, p, str_spec);
             break;
         case 'C':   /* full compatible string */
             has_mult = false;
             of_property_for_each_string(dn, "compatible", prop, p) {
                 if (has_mult)
                     buf = string_nocheck(buf, end, ",", str_spec);
                 buf = string_nocheck(buf, end, "\"", str_spec);
                 buf = string(buf, end, p, str_spec);
                 buf = string_nocheck(buf, end, "\"", str_spec);
 
                 has_mult = true;
             }
             break;
         default:
             break;
         }
     }
 
     return widen_string(buf, buf - buf_start, end, spec);
 }
 
 static noinline_for_stack
 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
             struct printf_spec spec, const char *fmt)
 {
     struct printf_spec str_spec = spec;
     char *buf_start = buf;
 
     str_spec.field_width = -1;
 
     if (*fmt != 'w')
         return error_string(buf, end, "(%pf?)", spec);
 
     if (check_pointer(&buf, end, fwnode, spec))
         return buf;
 
     fmt++;
 
     switch (*fmt) {
     case 'P':   /* name */
         buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
         break;
     case 'f':   /* full_name */
     default:
         buf = fwnode_full_name_string(fwnode, buf, end);
         break;
     }
 
     return widen_string(buf, buf - buf_start, end, spec);
 }
 
 int __init no_hash_pointers_enable(char *str)
 {
     if (no_hash_pointers)
         return 0;
 
     no_hash_pointers = true;
 
     pr_warn("**********************************************************\n");
     pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
     pr_warn("**                                                      **\n");
     pr_warn("** This system shows unhashed kernel memory addresses   **\n");
     pr_warn("** via the console, logs, and other interfaces. This    **\n");
     pr_warn("** might reduce the security of your system.            **\n");
     pr_warn("**                                                      **\n");
     pr_warn("** If you see this message and you are not debugging    **\n");
     pr_warn("** the kernel, report this immediately to your system   **\n");
     pr_warn("** administrator!                                       **\n");
     pr_warn("**                                                      **\n");
     pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
     pr_warn("**********************************************************\n");
 
     return 0;
 }
 early_param("no_hash_pointers", no_hash_pointers_enable);
 
 /*
  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
  * by an extra set of alphanumeric characters that are extended format
  * specifiers.
  *
  * Please update scripts/checkpatch.pl when adding/removing conversion
  * characters.  (Search for "check for vsprintf extension").
  *
  * Right now we handle:
  *
  * - 'S' For symbolic direct pointers (or function descriptors) with offset
  * - 's' For symbolic direct pointers (or function descriptors) without offset
  * - '[Ss]R' as above with __builtin_extract_return_addr() translation
  * - 'S[R]b' as above with module build ID (for use in backtraces)
  * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
  *      %ps and %pS. Be careful when re-using these specifiers.
  * - 'B' For backtraced symbolic direct pointers with offset
  * - 'Bb' as above with module build ID (for use in backtraces)
  * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
  * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
  * - 'b[l]' For a bitmap, the number of bits is determined by the field
  *       width which must be explicitly specified either as part of the
  *       format string '%32b[l]' or through '%*b[l]', [l] selects
  *       range-list format instead of hex format
  * - 'M' For a 6-byte MAC address, it prints the address in the
  *       usual colon-separated hex notation
  * - 'm' For a 6-byte MAC address, it prints the hex address without colons
  * - 'MF' For a 6-byte MAC FDDI address, it prints the address
  *       with a dash-separated hex notation
  * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
  *       IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
  *       IPv6 uses colon separated network-order 16 bit hex with leading 0's
  *       [S][pfs]
  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
  * - 'i' [46] for 'raw' IPv4/IPv6 addresses
  *       IPv6 omits the colons (01020304...0f)
  *       IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
  *       [S][pfs]
  *       Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
  *       [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
  * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
  * - 'I[6S]c' for IPv6 addresses printed as specified by
  *       https://tools.ietf.org/html/rfc5952
  * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
  *                of the following flags (see string_escape_mem() for the
  *                details):
  *                  a - ESCAPE_ANY
  *                  c - ESCAPE_SPECIAL
  *                  h - ESCAPE_HEX
  *                  n - ESCAPE_NULL
  *                  o - ESCAPE_OCTAL
  *                  p - ESCAPE_NP
  *                  s - ESCAPE_SPACE
  *                By default ESCAPE_ANY_NP is used.
  * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
  *       "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
  *       Options for %pU are:
  *         b big endian lower case hex (default)
  *         B big endian UPPER case hex
  *         l little endian lower case hex
  *         L little endian UPPER case hex
  *           big endian output byte order is:
  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
  *           little endian output byte order is:
  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
  * - 'V' For a struct va_format which contains a format string * and va_list *,
  *       call vsnprintf(->format, *->va_list).
  *       Implements a "recursive vsnprintf".
  *       Do not use this feature without some mechanism to verify the
  *       correctness of the format string and va_list arguments.
  * - 'K' For a kernel pointer that should be hidden from unprivileged users.
  *       Use only for procfs, sysfs and similar files, not printk(); please
  *       read the documentation (path below) first.
  * - 'NF' For a netdev_features_t
  * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
  * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
  *            a certain separator (' ' by default):
  *              C colon
  *              D dash
  *              N no separator
  *            The maximum supported length is 64 bytes of the input. Consider
  *            to use print_hex_dump() for the larger input.
  * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
  *           (default assumed to be phys_addr_t, passed by reference)
  * - 'd[234]' For a dentry name (optionally 2-4 last components)
  * - 'D[234]' Same as 'd' but for a struct file
  * - 'g' For block_device name (gendisk + partition number)
  * - 't[RT][dt][r][s]' For time and date as represented by:
  *      R    struct rtc_time
  *      T    time64_t
  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
  *       (legacy clock framework) of the clock
  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
  *        (legacy clock framework) of the clock
  * - 'G' For flags to be printed as a collection of symbolic strings that would
  *       construct the specific value. Supported flags given by option:
  *       p page flags (see struct page) given as pointer to unsigned long
  *       g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
  *       v vma flags (VM_*) given as pointer to unsigned long
  * - 'OF[fnpPcCF]'  For a device tree object
  *                  Without any optional arguments prints the full_name
  *                  f device node full_name
  *                  n device node name
  *                  p device node phandle
  *                  P device node path spec (name + @unit)
  *                  F device node flags
  *                  c major compatible string
  *                  C full compatible string
  * - 'fw[fP]'   For a firmware node (struct fwnode_handle) pointer
  *      Without an option prints the full name of the node
  *      f full name
  *      P node name, including a possible unit address
  * - 'x' For printing the address unmodified. Equivalent to "%lx".
  *       Please read the documentation (path below) before using!
  * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
  *           bpf_trace_printk() where [ku] prefix specifies either kernel (k)
  *           or user (u) memory to probe, and:
  *              s a string, equivalent to "%s" on direct vsnprintf() use
  *
  * ** When making changes please also update:
  *  Documentation/core-api/printk-formats.rst
  *
  * Note: The default behaviour (unadorned %p) is to hash the address,
  * rendering it useful as a unique identifier.
  */
 static noinline_for_stack
 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
           struct printf_spec spec)
 {
     switch (*fmt) {
     case 'S':
     case 's':
         ptr = dereference_symbol_descriptor(ptr);
         fallthrough;
     case 'B':
         return symbol_string(buf, end, ptr, spec, fmt);
     case 'R':
     case 'r':
         return resource_string(buf, end, ptr, spec, fmt);
     case 'h':
         return hex_string(buf, end, ptr, spec, fmt);
     case 'b':
         switch (fmt[1]) {
         case 'l':
             return bitmap_list_string(buf, end, ptr, spec, fmt);
         default:
             return bitmap_string(buf, end, ptr, spec, fmt);
         }
     case 'M':           /* Colon separated: 00:01:02:03:04:05 */
     case 'm':           /* Contiguous: 000102030405 */
                     /* [mM]F (FDDI) */
                     /* [mM]R (Reverse order; Bluetooth) */
         return mac_address_string(buf, end, ptr, spec, fmt);
     case 'I':           /* Formatted IP supported
                      * 4:   1.2.3.4
                      * 6:   0001:0203:...:0708
                      * 6c:  1::708 or 1::1.2.3.4
                      */
     case 'i':           /* Contiguous:
                      * 4:   001.002.003.004
                      * 6:   000102...0f
                      */
         return ip_addr_string(buf, end, ptr, spec, fmt);
     case 'E':
         return escaped_string(buf, end, ptr, spec, fmt);
     case 'U':
         return uuid_string(buf, end, ptr, spec, fmt);
     case 'V':
         return va_format(buf, end, ptr, spec, fmt);
     case 'K':
         return restricted_pointer(buf, end, ptr, spec);
     case 'N':
         return netdev_bits(buf, end, ptr, spec, fmt);
     case '4':
         return fourcc_string(buf, end, ptr, spec, fmt);
     case 'a':
         return address_val(buf, end, ptr, spec, fmt);
     case 'd':
         return dentry_name(buf, end, ptr, spec, fmt);
     case 't':
         return time_and_date(buf, end, ptr, spec, fmt);
     case 'C':
         return clock(buf, end, ptr, spec, fmt);
     case 'D':
         return file_dentry_name(buf, end, ptr, spec, fmt);
 #ifdef CONFIG_BLOCK
     case 'g':
         return bdev_name(buf, end, ptr, spec, fmt);
 #endif
 
     case 'G':
         return flags_string(buf, end, ptr, spec, fmt);
     case 'O':
         return device_node_string(buf, end, ptr, spec, fmt + 1);
     case 'f':
         return fwnode_string(buf, end, ptr, spec, fmt + 1);
     case 'x':
         return pointer_string(buf, end, ptr, spec);
     case 'e':
         /* %pe with a non-ERR_PTR gets treated as plain %p */
         if (!IS_ERR(ptr))
             return default_pointer(buf, end, ptr, spec);
         return err_ptr(buf, end, ptr, spec);
     case 'u':
     case 'k':
         switch (fmt[1]) {
         case 's':
             return string(buf, end, ptr, spec);
         default:
             return error_string(buf, end, "(einval)", spec);
         }
     default:
         return default_pointer(buf, end, ptr, spec);
     }
 }
 
 /*
  * Helper function to decode printf style format.
  * Each call decode a token from the format and return the
  * number of characters read (or likely the delta where it wants
  * to go on the next call).
  * The decoded token is returned through the parameters
  *
  * 'h', 'l', or 'L' for integer fields
  * 'z' support added 23/7/1999 S.H.
  * 'z' changed to 'Z' --davidm 1/25/99
  * 'Z' changed to 'z' --adobriyan 2017-01-25
  * 't' added for ptrdiff_t
  *
  * @fmt: the format string
  * @type of the token returned
  * @flags: various flags such as +, -, # tokens..
  * @field_width: overwritten width
  * @base: base of the number (octal, hex, ...)
  * @precision: precision of a number
  * @qualifier: qualifier of a number (long, size_t, ...)
  */
 static noinline_for_stack
 int format_decode(const char *fmt, struct printf_spec *spec)
 {
     const char *start = fmt;
     char qualifier;
 
     /* we finished early by reading the field width */
     if (spec->type == FORMAT_TYPE_WIDTH) {
         if (spec->field_width < 0) {
             spec->field_width = -spec->field_width;
             spec->flags |= LEFT;
         }
         spec->type = FORMAT_TYPE_NONE;
         goto precision;
     }
 
     /* we finished early by reading the precision */
     if (spec->type == FORMAT_TYPE_PRECISION) {
         if (spec->precision < 0)
             spec->precision = 0;
 
         spec->type = FORMAT_TYPE_NONE;
         goto qualifier;
     }
 
     /* By default */
     spec->type = FORMAT_TYPE_NONE;
 
     for (; *fmt ; ++fmt) {
         if (*fmt == '%')
             break;
     }
 
     /* Return the current non-format string */
     if (fmt != start || !*fmt)
         return fmt - start;
 
     /* Process flags */
     spec->flags = 0;
 
     while (1) { /* this also skips first '%' */
         bool found = true;
 
         ++fmt;
 
         switch (*fmt) {
         case '-': spec->flags |= LEFT;    break;
         case '+': spec->flags |= PLUS;    break;
         case ' ': spec->flags |= SPACE;   break;
         case '#': spec->flags |= SPECIAL; break;
         case '0': spec->flags |= ZEROPAD; break;
         default:  found = false;
         }
 
         if (!found)
             break;
     }
 
     /* get field width */
     spec->field_width = -1;
 
     if (isdigit(*fmt))
         spec->field_width = skip_atoi(&fmt);
     else if (*fmt == '*') {
         /* it's the next argument */
         spec->type = FORMAT_TYPE_WIDTH;
         return ++fmt - start;
     }
 
 precision:
     /* get the precision */
     spec->precision = -1;
     if (*fmt == '.') {
         ++fmt;
         if (isdigit(*fmt)) {
             spec->precision = skip_atoi(&fmt);
             if (spec->precision < 0)
                 spec->precision = 0;
         } else if (*fmt == '*') {
             /* it's the next argument */
             spec->type = FORMAT_TYPE_PRECISION;
             return ++fmt - start;
         }
     }
 
 qualifier:
     /* get the conversion qualifier */
     qualifier = 0;
     if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
         *fmt == 'z' || *fmt == 't') {
         qualifier = *fmt++;
         if (unlikely(qualifier == *fmt)) {
             if (qualifier == 'l') {
                 qualifier = 'L';
                 ++fmt;
             } else if (qualifier == 'h') {
                 qualifier = 'H';
                 ++fmt;
             }
         }
     }
 
     /* default base */
     spec->base = 10;
     switch (*fmt) {
     case 'c':
         spec->type = FORMAT_TYPE_CHAR;
         return ++fmt - start;
 
     case 's':
         spec->type = FORMAT_TYPE_STR;
         return ++fmt - start;
 
     case 'p':
         spec->type = FORMAT_TYPE_PTR;
         return ++fmt - start;
 
     case '%':
         spec->type = FORMAT_TYPE_PERCENT_CHAR;
         return ++fmt - start;
 
     /* integer number formats - set up the flags and "break" */
     case 'o':
         spec->base = 8;
         break;
 
     case 'x':
         spec->flags |= SMALL;
         fallthrough;
 
     case 'X':
         spec->base = 16;
         break;
 
     case 'd':
     case 'i':
         spec->flags |= SIGN;
         break;
     case 'u':
         break;
 
     case 'n':
         /*
          * Since %n poses a greater security risk than
          * utility, treat it as any other invalid or
          * unsupported format specifier.
          */
         fallthrough;
 
     default:
         WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
         spec->type = FORMAT_TYPE_INVALID;
         return fmt - start;
     }
 
     if (qualifier == 'L')
         spec->type = FORMAT_TYPE_LONG_LONG;
     else if (qualifier == 'l') {
         BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
         spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
     } else if (qualifier == 'z') {
         spec->type = FORMAT_TYPE_SIZE_T;
     } else if (qualifier == 't') {
         spec->type = FORMAT_TYPE_PTRDIFF;
     } else if (qualifier == 'H') {
         BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
         spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
     } else if (qualifier == 'h') {
         BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
         spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
     } else {
         BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
         spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
     }
 
     return ++fmt - start;
 }
 
 static void
 set_field_width(struct printf_spec *spec, int width)
 {
     spec->field_width = width;
     if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
         spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
     }
 }
 
 static void
 set_precision(struct printf_spec *spec, int prec)
 {
     spec->precision = prec;
     if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
         spec->precision = clamp(prec, 0, PRECISION_MAX);
     }
 }
 
 /**
  * vsnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @size: The size of the buffer, including the trailing null space
  * @fmt: The format string to use
  * @args: Arguments for the format string
  *
  * This function generally follows C99 vsnprintf, but has some
  * extensions and a few limitations:
  *
  *  - ``%n`` is unsupported
  *  - ``%p*`` is handled by pointer()
  *
  * See pointer() or Documentation/core-api/printk-formats.rst for more
  * extensive description.
  *
  * **Please update the documentation in both places when making changes**
  *
  * The return value is the number of characters which would
  * be generated for the given input, excluding the trailing
  * '\0', as per ISO C99. If you want to have the exact
  * number of characters written into @buf as return value
  * (not including the trailing '\0'), use vscnprintf(). If the
  * return is greater than or equal to @size, the resulting
  * string is truncated.
  *
  * If you're not already dealing with a va_list consider using snprintf().
  */
 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 {
     unsigned long long num;
     char *str, *end;
     struct printf_spec spec = {0};
 
     /* Reject out-of-range values early.  Large positive sizes are
        used for unknown buffer sizes. */
     if (WARN_ON_ONCE(size > INT_MAX))
         return 0;
 
     str = buf;
     end = buf + size;
 
     /* Make sure end is always >= buf */
     if (end < buf) {
         end = ((void *)-1);
         size = end - buf;
     }
 
     while (*fmt) {
         const char *old_fmt = fmt;
         int read = format_decode(fmt, &spec);
 
         fmt += read;
 
         switch (spec.type) {
         case FORMAT_TYPE_NONE: {
             int copy = read;
             if (str < end) {
                 if (copy > end - str)
                     copy = end - str;
                 memcpy(str, old_fmt, copy);
             }
             str += read;
             break;
         }
 
         case FORMAT_TYPE_WIDTH:
             set_field_width(&spec, va_arg(args, int));
             break;
 
         case FORMAT_TYPE_PRECISION:
             set_precision(&spec, va_arg(args, int));
             break;
 
         case FORMAT_TYPE_CHAR: {
             char c;
 
             if (!(spec.flags & LEFT)) {
                 while (--spec.field_width > 0) {
                     if (str < end)
                         *str = ' ';
                     ++str;
 
                 }
             }
             c = (unsigned char) va_arg(args, int);
             if (str < end)
                 *str = c;
             ++str;
             while (--spec.field_width > 0) {
                 if (str < end)
                     *str = ' ';
                 ++str;
             }
             break;
         }
 
         case FORMAT_TYPE_STR:
             str = string(str, end, va_arg(args, char *), spec);
             break;
 
         case FORMAT_TYPE_PTR:
             str = pointer(fmt, str, end, va_arg(args, void *),
                       spec);
             while (isalnum(*fmt))
                 fmt++;
             break;
 
         case FORMAT_TYPE_PERCENT_CHAR:
             if (str < end)
                 *str = '%';
             ++str;
             break;
 
         case FORMAT_TYPE_INVALID:
             /*
              * Presumably the arguments passed gcc's type
              * checking, but there is no safe or sane way
              * for us to continue parsing the format and
              * fetching from the va_list; the remaining
              * specifiers and arguments would be out of
              * sync.
              */
             goto out;
 
         default:
             switch (spec.type) {
             case FORMAT_TYPE_LONG_LONG:
                 num = va_arg(args, long long);
                 break;
             case FORMAT_TYPE_ULONG:
                 num = va_arg(args, unsigned long);
                 break;
             case FORMAT_TYPE_LONG:
                 num = va_arg(args, long);
                 break;
             case FORMAT_TYPE_SIZE_T:
                 if (spec.flags & SIGN)
                     num = va_arg(args, ssize_t);
                 else
                     num = va_arg(args, size_t);
                 break;
             case FORMAT_TYPE_PTRDIFF:
                 num = va_arg(args, ptrdiff_t);
                 break;
             case FORMAT_TYPE_UBYTE:
                 num = (unsigned char) va_arg(args, int);
                 break;
             case FORMAT_TYPE_BYTE:
                 num = (signed char) va_arg(args, int);
                 break;
             case FORMAT_TYPE_USHORT:
                 num = (unsigned short) va_arg(args, int);
                 break;
             case FORMAT_TYPE_SHORT:
                 num = (short) va_arg(args, int);
                 break;
             case FORMAT_TYPE_INT:
                 num = (int) va_arg(args, int);
                 break;
             default:
                 num = va_arg(args, unsigned int);
             }
 
             str = number(str, end, num, spec);
         }
     }
 
 out:
     if (size > 0) {
         if (str < end)
             *str = '\0';
         else
             end[-1] = '\0';
     }
 
     /* the trailing null byte doesn't count towards the total */
     return str-buf;
 
 }
 EXPORT_SYMBOL(vsnprintf);
 
 /**
  * vscnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @size: The size of the buffer, including the trailing null space
  * @fmt: The format string to use
  * @args: Arguments for the format string
  *
  * The return value is the number of characters which have been written into
  * the @buf not including the trailing '\0'. If @size is == 0 the function
  * returns 0.
  *
  * If you're not already dealing with a va_list consider using scnprintf().
  *
  * See the vsnprintf() documentation for format string extensions over C99.
  */
 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 {
     int i;
 
     if (unlikely(!size))
         return 0;
 
     i = vsnprintf(buf, size, fmt, args);
 
     if (likely(i < size))
         return i;
 
     return size - 1;
 }
 EXPORT_SYMBOL(vscnprintf);
 
 /**
  * snprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @size: The size of the buffer, including the trailing null space
  * @fmt: The format string to use
  * @...: Arguments for the format string
  *
  * The return value is the number of characters which would be
  * generated for the given input, excluding the trailing null,
  * as per ISO C99.  If the return is greater than or equal to
  * @size, the resulting string is truncated.
  *
  * See the vsnprintf() documentation for format string extensions over C99.
  */
 int snprintf(char *buf, size_t size, const char *fmt, ...)
 {
     va_list args;
     int i;
 
     va_start(args, fmt);
     i = vsnprintf(buf, size, fmt, args);
     va_end(args);
 
     return i;
 }
 EXPORT_SYMBOL(snprintf);
 
 /**
  * scnprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @size: The size of the buffer, including the trailing null space
  * @fmt: The format string to use
  * @...: Arguments for the format string
  *
  * The return value is the number of characters written into @buf not including
  * the trailing '\0'. If @size is == 0 the function returns 0.
  */
 
 int scnprintf(char *buf, size_t size, const char *fmt, ...)
 {
     va_list args;
     int i;
 
     va_start(args, fmt);
     i = vscnprintf(buf, size, fmt, args);
     va_end(args);
 
     return i;
 }
 EXPORT_SYMBOL(scnprintf);
 
 /**
  * vsprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @fmt: The format string to use
  * @args: Arguments for the format string
  *
  * The function returns the number of characters written
  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
  * buffer overflows.
  *
  * If you're not already dealing with a va_list consider using sprintf().
  *
  * See the vsnprintf() documentation for format string extensions over C99.
  */
 int vsprintf(char *buf, const char *fmt, va_list args)
 {
     return vsnprintf(buf, INT_MAX, fmt, args);
 }
 EXPORT_SYMBOL(vsprintf);
 
 /**
  * sprintf - Format a string and place it in a buffer
  * @buf: The buffer to place the result into
  * @fmt: The format string to use
  * @...: Arguments for the format string
  *
  * The function returns the number of characters written
  * into @buf. Use snprintf() or scnprintf() in order to avoid
  * buffer overflows.
  *
  * See the vsnprintf() documentation for format string extensions over C99.
  */
 int sprintf(char *buf, const char *fmt, ...)
 {
     va_list args;
     int i;
 
     va_start(args, fmt);
     i = vsnprintf(buf, INT_MAX, fmt, args);
     va_end(args);
 
     return i;
 }
 EXPORT_SYMBOL(sprintf);
 
 #ifdef CONFIG_BINARY_PRINTF
 /*
  * bprintf service:
  * vbin_printf() - VA arguments to binary data
  * bstr_printf() - Binary data to text string
  */
 
 /**
  * vbin_printf - Parse a format string and place args' binary value in a buffer
  * @bin_buf: The buffer to place args' binary value
  * @size: The size of the buffer(by words(32bits), not characters)
  * @fmt: The format string to use
  * @args: Arguments for the format string
  *
  * The format follows C99 vsnprintf, except %n is ignored, and its argument
  * is skipped.
  *
  * The return value is the number of words(32bits) which would be generated for
  * the given input.
  *
  * NOTE:
  * If the return value is greater than @size, the resulting bin_buf is NOT
  * valid for bstr_printf().
  */
 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
 {
     struct printf_spec spec = {0};
     char *str, *end;
     int width;
 
     str = (char *)bin_buf;
     end = (char *)(bin_buf + size);
 
 #define save_arg(type)                          \
 ({                                  \
     unsigned long long value;                   \
     if (sizeof(type) == 8) {                    \
         unsigned long long val8;                \
         str = PTR_ALIGN(str, sizeof(u32));          \
         val8 = va_arg(args, unsigned long long);        \
         if (str + sizeof(type) <= end) {            \
             *(u32 *)str = *(u32 *)&val8;            \
             *(u32 *)(str + 4) = *((u32 *)&val8 + 1);    \
         }                           \
         value = val8;                       \
     } else {                            \
         unsigned int val4;                  \
         str = PTR_ALIGN(str, sizeof(type));         \
         val4 = va_arg(args, int);               \
         if (str + sizeof(type) <= end)              \
             *(typeof(type) *)str = (type)(long)val4;    \
         value = (unsigned long long)val4;           \
     }                               \
     str += sizeof(type);                        \
     value;                              \
 })
 
     while (*fmt) {
         int read = format_decode(fmt, &spec);
 
         fmt += read;
 
         switch (spec.type) {
         case FORMAT_TYPE_NONE:
         case FORMAT_TYPE_PERCENT_CHAR:
             break;
         case FORMAT_TYPE_INVALID:
             goto out;
 
         case FORMAT_TYPE_WIDTH:
         case FORMAT_TYPE_PRECISION:
             width = (int)save_arg(int);
             /* Pointers may require the width */
             if (*fmt == 'p')
                 set_field_width(&spec, width);
             break;
 
         case FORMAT_TYPE_CHAR:
             save_arg(char);
             break;
 
         case FORMAT_TYPE_STR: {
             const char *save_str = va_arg(args, char *);
             const char *err_msg;
             size_t len;
 
             err_msg = check_pointer_msg(save_str);
             if (err_msg)
                 save_str = err_msg;
 
             len = strlen(save_str) + 1;
             if (str + len < end)
                 memcpy(str, save_str, len);
             str += len;
             break;
         }
 
         case FORMAT_TYPE_PTR:
             /* Dereferenced pointers must be done now */
             switch (*fmt) {
             /* Dereference of functions is still OK */
             case 'S':
             case 's':
             case 'x':
             case 'K':
             case 'e':
                 save_arg(void *);
                 break;
             default:
                 if (!isalnum(*fmt)) {
                     save_arg(void *);
                     break;
                 }
                 str = pointer(fmt, str, end, va_arg(args, void *),
                           spec);
                 if (str + 1 < end)
                     *str++ = '\0';
                 else
                     end[-1] = '\0'; /* Must be nul terminated */
             }
             /* skip all alphanumeric pointer suffixes */
             while (isalnum(*fmt))
                 fmt++;
             break;
 
         default:
             switch (spec.type) {
 
             case FORMAT_TYPE_LONG_LONG:
                 save_arg(long long);
                 break;
             case FORMAT_TYPE_ULONG:
             case FORMAT_TYPE_LONG:
                 save_arg(unsigned long);
                 break;
             case FORMAT_TYPE_SIZE_T:
                 save_arg(size_t);
                 break;
             case FORMAT_TYPE_PTRDIFF:
                 save_arg(ptrdiff_t);
                 break;
             case FORMAT_TYPE_UBYTE:
             case FORMAT_TYPE_BYTE:
                 save_arg(char);
                 break;
             case FORMAT_TYPE_USHORT:
             case FORMAT_TYPE_SHORT:
                 save_arg(short);
                 break;
             default:
                 save_arg(int);
             }
         }
     }
 
 out:
     return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
 #undef save_arg
 }
 EXPORT_SYMBOL_GPL(vbin_printf);
 
 /**
  * bstr_printf - Format a string from binary arguments and place it in a buffer
  * @buf: The buffer to place the result into
  * @size: The size of the buffer, including the trailing null space
  * @fmt: The format string to use
  * @bin_buf: Binary arguments for the format string
  *
  * This function like C99 vsnprintf, but the difference is that vsnprintf gets
  * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
  * a binary buffer that generated by vbin_printf.
  *
  * The format follows C99 vsnprintf, but has some extensions:
  *  see vsnprintf comment for details.
  *
  * The return value is the number of characters which would
  * be generated for the given input, excluding the trailing
  * '\0', as per ISO C99. If you want to have the exact
  * number of characters written into @buf as return value
  * (not including the trailing '\0'), use vscnprintf(). If the
  * return is greater than or equal to @size, the resulting
  * string is truncated.
  */
 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 {
     struct printf_spec spec = {0};
     char *str, *end;
     const char *args = (const char *)bin_buf;
 
     if (WARN_ON_ONCE(size > INT_MAX))
         return 0;
 
     str = buf;
     end = buf + size;
 
 #define get_arg(type)                           \
 ({                                  \
     typeof(type) value;                     \
     if (sizeof(type) == 8) {                    \
         args = PTR_ALIGN(args, sizeof(u32));            \
         *(u32 *)&value = *(u32 *)args;              \
         *((u32 *)&value + 1) = *(u32 *)(args + 4);      \
     } else {                            \
         args = PTR_ALIGN(args, sizeof(type));           \
         value = *(typeof(type) *)args;              \
     }                               \
     args += sizeof(type);                       \
     value;                              \
 })
 
     /* Make sure end is always >= buf */
     if (end < buf) {
         end = ((void *)-1);
         size = end - buf;
     }
 
     while (*fmt) {
         const char *old_fmt = fmt;
         int read = format_decode(fmt, &spec);
 
         fmt += read;
 
         switch (spec.type) {
         case FORMAT_TYPE_NONE: {
             int copy = read;
             if (str < end) {
                 if (copy > end - str)
                     copy = end - str;
                 memcpy(str, old_fmt, copy);
             }
             str += read;
             break;
         }
 
         case FORMAT_TYPE_WIDTH:
             set_field_width(&spec, get_arg(int));
             break;
 
         case FORMAT_TYPE_PRECISION:
             set_precision(&spec, get_arg(int));
             break;
 
         case FORMAT_TYPE_CHAR: {
             char c;
 
             if (!(spec.flags & LEFT)) {
                 while (--spec.field_width > 0) {
                     if (str < end)
                         *str = ' ';
                     ++str;
                 }
             }
             c = (unsigned char) get_arg(char);
             if (str < end)
                 *str = c;
             ++str;
             while (--spec.field_width > 0) {
                 if (str < end)
                     *str = ' ';
                 ++str;
             }
             break;
         }
 
         case FORMAT_TYPE_STR: {
             const char *str_arg = args;
             args += strlen(str_arg) + 1;
             str = string(str, end, (char *)str_arg, spec);
             break;
         }
 
         case FORMAT_TYPE_PTR: {
             bool process = false;
             int copy, len;
             /* Non function dereferences were already done */
             switch (*fmt) {
             case 'S':
             case 's':
             case 'x':
             case 'K':
             case 'e':
                 process = true;
                 break;
             default:
                 if (!isalnum(*fmt)) {
                     process = true;
                     break;
                 }
                 /* Pointer dereference was already processed */
                 if (str < end) {
                     len = copy = strlen(args);
                     if (copy > end - str)
                         copy = end - str;
                     memcpy(str, args, copy);
                     str += len;
                     args += len + 1;
                 }
             }
             if (process)
                 str = pointer(fmt, str, end, get_arg(void *), spec);
 
             while (isalnum(*fmt))
                 fmt++;
             break;
         }
 
         case FORMAT_TYPE_PERCENT_CHAR:
             if (str < end)
                 *str = '%';
             ++str;
             break;
 
         case FORMAT_TYPE_INVALID:
             goto out;
 
         default: {
             unsigned long long num;
 
             switch (spec.type) {
 
             case FORMAT_TYPE_LONG_LONG:
                 num = get_arg(long long);
                 break;
             case FORMAT_TYPE_ULONG:
             case FORMAT_TYPE_LONG:
                 num = get_arg(unsigned long);
                 break;
             case FORMAT_TYPE_SIZE_T:
                 num = get_arg(size_t);
                 break;
             case FORMAT_TYPE_PTRDIFF:
                 num = get_arg(ptrdiff_t);
                 break;
             case FORMAT_TYPE_UBYTE:
                 num = get_arg(unsigned char);
                 break;
             case FORMAT_TYPE_BYTE:
                 num = get_arg(signed char);
                 break;
             case FORMAT_TYPE_USHORT:
                 num = get_arg(unsigned short);
                 break;
             case FORMAT_TYPE_SHORT:
                 num = get_arg(short);
                 break;
             case FORMAT_TYPE_UINT:
                 num = get_arg(unsigned int);
                 break;
             default:
                 num = get_arg(int);
             }
 
             str = number(str, end, num, spec);
         } /* default: */
         } /* switch(spec.type) */
     } /* while(*fmt) */
 
 out:
     if (size > 0) {
         if (str < end)
             *str = '\0';
         else
             end[-1] = '\0';
     }
 
 #undef get_arg
 
     /* the trailing null byte doesn't count towards the total */
     return str - buf;
 }
 EXPORT_SYMBOL_GPL(bstr_printf);
 
 /**
  * bprintf - Parse a format string and place args' binary value in a buffer
  * @bin_buf: The buffer to place args' binary value
  * @size: The size of the buffer(by words(32bits), not characters)
  * @fmt: The format string to use
  * @...: Arguments for the format string
  *
  * The function returns the number of words(u32) written
  * into @bin_buf.
  */
 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
 {
     va_list args;
     int ret;
 
     va_start(args, fmt);
     ret = vbin_printf(bin_buf, size, fmt, args);
     va_end(args);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(bprintf);
 
 #endif /* CONFIG_BINARY_PRINTF */
 
 /**
  * vsscanf - Unformat a buffer into a list of arguments
  * @buf:    input buffer
  * @fmt:    format of buffer
  * @args:   arguments
  */
 int vsscanf(const char *buf, const char *fmt, va_list args)
 {
     const char *str = buf;
     char *next;
     char digit;
     int num = 0;
     u8 qualifier;
     unsigned int base;
     union {
         long long s;
         unsigned long long u;
     } val;
     s16 field_width;
     bool is_sign;
 
     while (*fmt) {
         /* skip any white space in format */
         /* white space in format matches any amount of
          * white space, including none, in the input.
          */
         if (isspace(*fmt)) {
             fmt = skip_spaces(++fmt);
             str = skip_spaces(str);
         }
 
         /* anything that is not a conversion must match exactly */
         if (*fmt != '%' && *fmt) {
             if (*fmt++ != *str++)
                 break;
             continue;
         }
 
         if (!*fmt)
             break;
         ++fmt;
 
         /* skip this conversion.
          * advance both strings to next white space
          */
         if (*fmt == '*') {
             if (!*str)
                 break;
             while (!isspace(*fmt) && *fmt != '%' && *fmt) {
                 /* '%*[' not yet supported, invalid format */
                 if (*fmt == '[')
                     return num;
                 fmt++;
             }
             while (!isspace(*str) && *str)
                 str++;
             continue;
         }
 
         /* get field width */
         field_width = -1;
         if (isdigit(*fmt)) {
             field_width = skip_atoi(&fmt);
             if (field_width <= 0)
                 break;
         }
 
         /* get conversion qualifier */
         qualifier = -1;
         if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
             *fmt == 'z') {
             qualifier = *fmt++;
             if (unlikely(qualifier == *fmt)) {
                 if (qualifier == 'h') {
                     qualifier = 'H';
                     fmt++;
                 } else if (qualifier == 'l') {
                     qualifier = 'L';
                     fmt++;
                 }
             }
         }
 
         if (!*fmt)
             break;
 
         if (*fmt == 'n') {
             /* return number of characters read so far */
             *va_arg(args, int *) = str - buf;
             ++fmt;
             continue;
         }
 
         if (!*str)
             break;
 
         base = 10;
         is_sign = false;
 
         switch (*fmt++) {
         case 'c':
         {
             char *s = (char *)va_arg(args, char*);
             if (field_width == -1)
                 field_width = 1;
             do {
                 *s++ = *str++;
             } while (--field_width > 0 && *str);
             num++;
         }
         continue;
         case 's':
         {
             char *s = (char *)va_arg(args, char *);
             if (field_width == -1)
                 field_width = SHRT_MAX;
             /* first, skip leading white space in buffer */
             str = skip_spaces(str);
 
             /* now copy until next white space */
             while (*str && !isspace(*str) && field_width--)
                 *s++ = *str++;
             *s = '\0';
             num++;
         }
         continue;
         /*
          * Warning: This implementation of the '[' conversion specifier
          * deviates from its glibc counterpart in the following ways:
          * (1) It does NOT support ranges i.e. '-' is NOT a special
          *     character
          * (2) It cannot match the closing bracket ']' itself
          * (3) A field width is required
          * (4) '%*[' (discard matching input) is currently not supported
          *
          * Example usage:
          * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
          *      buf1, buf2, buf3);
          * if (ret < 3)
          *    // etc..
          */
         case '[':
         {
             char *s = (char *)va_arg(args, char *);
             DECLARE_BITMAP(set, 256) = {0};
             unsigned int len = 0;
             bool negate = (*fmt == '^');
 
             /* field width is required */
             if (field_width == -1)
                 return num;
 
             if (negate)
                 ++fmt;
 
             for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
                 __set_bit((u8)*fmt, set);
 
             /* no ']' or no character set found */
             if (!*fmt || !len)
                 return num;
             ++fmt;
 
             if (negate) {
                 bitmap_complement(set, set, 256);
                 /* exclude null '\0' byte */
                 __clear_bit(0, set);
             }
 
             /* match must be non-empty */
             if (!test_bit((u8)*str, set))
                 return num;
 
             while (test_bit((u8)*str, set) && field_width--)
                 *s++ = *str++;
             *s = '\0';
             ++num;
         }
         continue;
         case 'o':
             base = 8;
             break;
         case 'x':
         case 'X':
             base = 16;
             break;
         case 'i':
             base = 0;
             fallthrough;
         case 'd':
             is_sign = true;
             fallthrough;
         case 'u':
             break;
         case '%':
             /* looking for '%' in str */
             if (*str++ != '%')
                 return num;
             continue;
         default:
             /* invalid format; stop here */
             return num;
         }
 
         /* have some sort of integer conversion.
          * first, skip white space in buffer.
          */
         str = skip_spaces(str);
 
         digit = *str;
         if (is_sign && digit == '-') {
             if (field_width == 1)
                 break;
 
             digit = *(str + 1);
         }
 
         if (!digit
             || (base == 16 && !isxdigit(digit))
             || (base == 10 && !isdigit(digit))
             || (base == 8 && (!isdigit(digit) || digit > '7'))
             || (base == 0 && !isdigit(digit)))
             break;
 
         if (is_sign)
             val.s = simple_strntoll(str,
                         field_width >= 0 ? field_width : INT_MAX,
                         &next, base);
         else
             val.u = simple_strntoull(str,
                          field_width >= 0 ? field_width : INT_MAX,
                          &next, base);
 
         switch (qualifier) {
         case 'H':   /* that's 'hh' in format */
             if (is_sign)
                 *va_arg(args, signed char *) = val.s;
             else
                 *va_arg(args, unsigned char *) = val.u;
             break;
         case 'h':
             if (is_sign)
                 *va_arg(args, short *) = val.s;
             else
                 *va_arg(args, unsigned short *) = val.u;
             break;
         case 'l':
             if (is_sign)
                 *va_arg(args, long *) = val.s;
             else
                 *va_arg(args, unsigned long *) = val.u;
             break;
         case 'L':
             if (is_sign)
                 *va_arg(args, long long *) = val.s;
             else
                 *va_arg(args, unsigned long long *) = val.u;
             break;
         case 'z':
             *va_arg(args, size_t *) = val.u;
             break;
         default:
             if (is_sign)
                 *va_arg(args, int *) = val.s;
             else
                 *va_arg(args, unsigned int *) = val.u;
             break;
         }
         num++;
 
         if (!next)
             break;
         str = next;
     }
 
     return num;
 }
 EXPORT_SYMBOL(vsscanf);
 
 /**
  * sscanf - Unformat a buffer into a list of arguments
  * @buf:    input buffer
  * @fmt:    formatting of buffer
  * @...:    resulting arguments
  */
 int sscanf(const char *buf, const char *fmt, ...)
 {
     va_list args;
     int i;
 
     va_start(args, fmt);
     i = vsscanf(buf, fmt, args);
     va_end(args);
 
     return i;
 }
 EXPORT_SYMBOL(sscanf);