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linux-hardened/lib/vsprintf.c
Linus Torvalds 0fe1ef24f7 vsprintf: add support for '%pS' and '%pF' pointer formats 
They print out a pointer in symbolic format, if possible (ie using
symbolic KALLSYMS information).  The '%pS' format is for regular direct
pointers (which can point to data or code and that you find on the stack
during backtraces etc), while '%pF' is for C function pointer types.

On most architectures, the two mean exactly the same thing, but some
architectures use an indirect pointer for C function pointers, where the
function pointer points to a function descriptor (which in turn contains
the actual pointer to the code).  The '%pF' code automatically does the
appropriate function descriptor dereference on such architectures.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-06 16:55:51 -07:00

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/*
* 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 <stdarg.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <asm/page.h> /* for PAGE_SIZE */
#include <asm/div64.h>
/* Works only for digits and letters, but small and fast */
#define TOLOWER(x) ((x) | 0x20)
/**
* 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
*/
unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
{
unsigned long result = 0,value;
if (!base) {
base = 10;
if (*cp == '0') {
base = 8;
cp++;
if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
cp++;
base = 16;
}
}
} else if (base == 16) {
if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
cp += 2;
}
while (isxdigit(*cp) &&
(value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
result = result*base + value;
cp++;
}
if (endp)
*endp = (char *)cp;
return result;
}
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
*/
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);
/**
* 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
*/
unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
{
unsigned long long result = 0,value;
if (!base) {
base = 10;
if (*cp == '0') {
base = 8;
cp++;
if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) {
cp++;
base = 16;
}
}
} else if (base == 16) {
if (cp[0] == '0' && TOLOWER(cp[1]) == 'x')
cp += 2;
}
while (isxdigit(*cp)
&& (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) {
result = result*base + value;
cp++;
}
if (endp)
*endp = (char *)cp;
return result;
}
EXPORT_SYMBOL(simple_strtoull);
/**
* 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
*/
long long simple_strtoll(const char *cp,char **endp,unsigned int base)
{
if(*cp=='-')
return -simple_strtoull(cp+1,endp,base);
return simple_strtoull(cp,endp,base);
}
/**
* strict_strtoul - convert a string to an unsigned long strictly
* @cp: The string to be converted
* @base: The number base to use
* @res: The converted result value
*
* strict_strtoul converts a string to an unsigned long only if the
* string is really an unsigned long string, any string containing
* any invalid char at the tail will be rejected and -EINVAL is returned,
* only a newline char at the tail is acceptible because people generally
* change a module parameter in the following way:
*
* echo 1024 > /sys/module/e1000/parameters/copybreak
*
* echo will append a newline to the tail.
*
* It returns 0 if conversion is successful and *res is set to the converted
* value, otherwise it returns -EINVAL and *res is set to 0.
*
* simple_strtoul just ignores the successive invalid characters and
* return the converted value of prefix part of the string.
*/
int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
/**
* strict_strtol - convert a string to a long strictly
* @cp: The string to be converted
* @base: The number base to use
* @res: The converted result value
*
* strict_strtol is similiar to strict_strtoul, but it allows the first
* character of a string is '-'.
*
* It returns 0 if conversion is successful and *res is set to the converted
* value, otherwise it returns -EINVAL and *res is set to 0.
*/
int strict_strtol(const char *cp, unsigned int base, long *res);
/**
* strict_strtoull - convert a string to an unsigned long long strictly
* @cp: The string to be converted
* @base: The number base to use
* @res: The converted result value
*
* strict_strtoull converts a string to an unsigned long long only if the
* string is really an unsigned long long string, any string containing
* any invalid char at the tail will be rejected and -EINVAL is returned,
* only a newline char at the tail is acceptible because people generally
* change a module parameter in the following way:
*
* echo 1024 > /sys/module/e1000/parameters/copybreak
*
* echo will append a newline to the tail of the string.
*
* It returns 0 if conversion is successful and *res is set to the converted
* value, otherwise it returns -EINVAL and *res is set to 0.
*
* simple_strtoull just ignores the successive invalid characters and
* return the converted value of prefix part of the string.
*/
int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res);
/**
* strict_strtoll - convert a string to a long long strictly
* @cp: The string to be converted
* @base: The number base to use
* @res: The converted result value
*
* strict_strtoll is similiar to strict_strtoull, but it allows the first
* character of a string is '-'.
*
* It returns 0 if conversion is successful and *res is set to the converted
* value, otherwise it returns -EINVAL and *res is set to 0.
*/
int strict_strtoll(const char *cp, unsigned int base, long long *res);
#define define_strict_strtoux(type, valtype) \
int strict_strtou##type(const char *cp, unsigned int base, valtype *res)\
{ \
char *tail; \
valtype val; \
size_t len; \
\
*res = 0; \
len = strlen(cp); \
if (len == 0) \
return -EINVAL; \
\
val = simple_strtoul(cp, &tail, base); \
if ((*tail == '\0') || \
((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {\
*res = val; \
return 0; \
} \
\
return -EINVAL; \
} \
#define define_strict_strtox(type, valtype) \
int strict_strto##type(const char *cp, unsigned int base, valtype *res) \
{ \
int ret; \
if (*cp == '-') { \
ret = strict_strtou##type(cp+1, base, res); \
if (!ret) \
*res = -(*res); \
} else \
ret = strict_strtou##type(cp, base, res); \
\
return ret; \
} \
define_strict_strtoux(l, unsigned long)
define_strict_strtox(l, long)
define_strict_strtoux(ll, unsigned long long)
define_strict_strtox(ll, long long)
EXPORT_SYMBOL(strict_strtoul);
EXPORT_SYMBOL(strict_strtol);
EXPORT_SYMBOL(strict_strtoll);
EXPORT_SYMBOL(strict_strtoull);
static int skip_atoi(const char **s)
{
int i=0;
while (isdigit(**s))
i = i*10 + *((*s)++) - '0';
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
* using code from
* http://www.cs.uiowa.edu/~jones/bcd/decimal.html
* (with permission from the author, Douglas W. Jones). */
/* Formats correctly any integer in [0,99999].
* Outputs from one to five digits depending on input.
* On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
static char* put_dec_trunc(char *buf, unsigned q)
{
unsigned d3, d2, d1, d0;
d1 = (q>>4) & 0xf;
d2 = (q>>8) & 0xf;
d3 = (q>>12);
d0 = 6*(d3 + d2 + d1) + (q & 0xf);
q = (d0 * 0xcd) >> 11;
d0 = d0 - 10*q;
*buf++ = d0 + '0'; /* least significant digit */
d1 = q + 9*d3 + 5*d2 + d1;
if (d1 != 0) {
q = (d1 * 0xcd) >> 11;
d1 = d1 - 10*q;
*buf++ = d1 + '0'; /* next digit */
d2 = q + 2*d2;
if ((d2 != 0) || (d3 != 0)) {
q = (d2 * 0xd) >> 7;
d2 = d2 - 10*q;
*buf++ = d2 + '0'; /* next digit */
d3 = q + 4*d3;
if (d3 != 0) {
q = (d3 * 0xcd) >> 11;
d3 = d3 - 10*q;
*buf++ = d3 + '0'; /* next digit */
if (q != 0)
*buf++ = q + '0'; /* most sign. digit */
}
}
}
return buf;
}
/* Same with if's removed. Always emits five digits */
static char* put_dec_full(char *buf, unsigned q)
{
/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
/* but anyway, gcc produces better code with full-sized ints */
unsigned d3, d2, d1, d0;
d1 = (q>>4) & 0xf;
d2 = (q>>8) & 0xf;
d3 = (q>>12);
/* Possible ways to approx. divide by 10 */
/* gcc -O2 replaces multiply with shifts and adds */
// (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
// (x * 0x67) >> 10: 1100111
// (x * 0x34) >> 9: 110100 - same
// (x * 0x1a) >> 8: 11010 - same
// (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
d0 = 6*(d3 + d2 + d1) + (q & 0xf);
q = (d0 * 0xcd) >> 11;
d0 = d0 - 10*q;
*buf++ = d0 + '0';
d1 = q + 9*d3 + 5*d2 + d1;
q = (d1 * 0xcd) >> 11;
d1 = d1 - 10*q;
*buf++ = d1 + '0';
d2 = q + 2*d2;
q = (d2 * 0xd) >> 7;
d2 = d2 - 10*q;
*buf++ = d2 + '0';
d3 = q + 4*d3;
q = (d3 * 0xcd) >> 11; /* - shorter code */
/* q = (d3 * 0x67) >> 10; - would also work */
d3 = d3 - 10*q;
*buf++ = d3 + '0';
*buf++ = q + '0';
return buf;
}
/* No inlining helps gcc to use registers better */
static noinline char* put_dec(char *buf, unsigned long long num)
{
while (1) {
unsigned rem;
if (num < 100000)
return put_dec_trunc(buf, num);
rem = do_div(num, 100000);
buf = put_dec_full(buf, rem);
}
}
#define ZEROPAD 1 /* pad with zero */
#define SIGN 2 /* unsigned/signed long */
#define PLUS 4 /* show plus */
#define SPACE 8 /* space if plus */
#define LEFT 16 /* left justified */
#define SMALL 32 /* Must be 32 == 0x20 */
#define SPECIAL 64 /* 0x */
static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
{
/* we are called with base 8, 10 or 16, only, thus don't need "G..." */
static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
char tmp[66];
char sign;
char locase;
int need_pfx = ((type & SPECIAL) && base != 10);
int i;
/* locase = 0 or 0x20. ORing digits or letters with 'locase'
* produces same digits or (maybe lowercased) letters */
locase = (type & SMALL);
if (type & LEFT)
type &= ~ZEROPAD;
sign = 0;
if (type & SIGN) {
if ((signed long long) num < 0) {
sign = '-';
num = - (signed long long) num;
size--;
} else if (type & PLUS) {
sign = '+';
size--;
} else if (type & SPACE) {
sign = ' ';
size--;
}
}
if (need_pfx) {
size--;
if (base == 16)
size--;
}
/* generate full string in tmp[], in reverse order */
i = 0;
if (num == 0)
tmp[i++] = '0';
/* Generic code, for any base:
else do {
tmp[i++] = (digits[do_div(num,base)] | locase);
} while (num != 0);
*/
else if (base != 10) { /* 8 or 16 */
int mask = base - 1;
int shift = 3;
if (base == 16) shift = 4;
do {
tmp[i++] = (digits[((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 */
size -= precision;
if (!(type & (ZEROPAD+LEFT))) {
while(--size >= 0) {
if (buf < end)
*buf = ' ';
++buf;
}
}
/* sign */
if (sign) {
if (buf < end)
*buf = sign;
++buf;
}
/* "0x" / "0" prefix */
if (need_pfx) {
if (buf < end)
*buf = '0';
++buf;
if (base == 16) {
if (buf < end)
*buf = ('X' | locase);
++buf;
}
}
/* zero or space padding */
if (!(type & LEFT)) {
char c = (type & ZEROPAD) ? '0' : ' ';
while (--size >= 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 (--size >= 0) {
if (buf < end)
*buf = ' ';
++buf;
}
return buf;
}
static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags)
{
int len, i;
if ((unsigned long)s < PAGE_SIZE)
s = "<NULL>";
len = strnlen(s, precision);
if (!(flags & LEFT)) {
while (len < field_width--) {
if (buf < end)
*buf = ' ';
++buf;
}
}
for (i = 0; i < len; ++i) {
if (buf < end)
*buf = *s;
++buf; ++s;
}
while (len < field_width--) {
if (buf < end)
*buf = ' ';
++buf;
}
return buf;
}
static inline void *dereference_function_descriptor(void *ptr)
{
#if defined(CONFIG_IA64) || defined(CONFIG_PPC64)
void *p;
if (!probe_kernel_address(ptr, p))
ptr = p;
#endif
return ptr;
}
static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags)
{
unsigned long value = (unsigned long) ptr;
#ifdef CONFIG_KALLSYMS
char sym[KSYM_SYMBOL_LEN];
sprint_symbol(sym, value);
return string(buf, end, sym, field_width, precision, flags);
#else
field_width = 2*sizeof(void *);
flags |= SPECIAL | SMALL | ZEROPAD;
return number(buf, end, value, 16, field_width, precision, flags);
#endif
}
/*
* 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.
*
* Right now we just handle 'F' (for symbolic Function descriptor pointers)
* and 'S' (for Symbolic direct pointers), but this can easily be
* extended in the future (network address types etc).
*
* The difference between 'S' and 'F' is that on ia64 and ppc64 function
* pointers are really function descriptors, which contain a pointer the
* real address.
*/
static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags)
{
switch (*fmt) {
case 'F':
ptr = dereference_function_descriptor(ptr);
/* Fallthrough */
case 'S':
return symbol_string(buf, end, ptr, field_width, precision, flags);
}
flags |= SMALL;
if (field_width == -1) {
field_width = 2*sizeof(void *);
flags |= ZEROPAD;
}
return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags);
}
/**
* 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
*
* 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.
*
* Call this function if you are already dealing with a va_list.
* You probably want snprintf() instead.
*/
int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
unsigned long long num;
int base;
char *str, *end, c;
int flags; /* flags to number() */
int field_width; /* width of output field */
int precision; /* min. # of digits for integers; max
number of chars for from string */
int qualifier; /* 'h', 'l', or 'L' for integer fields */
/* 'z' support added 23/7/1999 S.H. */
/* 'z' changed to 'Z' --davidm 1/25/99 */
/* 't' added for ptrdiff_t */
/* Reject out-of-range values early. Large positive sizes are
used for unknown buffer sizes. */
if (unlikely((int) size < 0)) {
/* There can be only one.. */
static char warn = 1;
WARN_ON(warn);
warn = 0;
return 0;
}
str = buf;
end = buf + size;
/* Make sure end is always >= buf */
if (end < buf) {
end = ((void *)-1);
size = end - buf;
}
for (; *fmt ; ++fmt) {
if (*fmt != '%') {
if (str < end)
*str = *fmt;
++str;
continue;
}
/* process flags */
flags = 0;
repeat:
++fmt; /* this also skips first '%' */
switch (*fmt) {
case '-': flags |= LEFT; goto repeat;
case '+': flags |= PLUS; goto repeat;
case ' ': flags |= SPACE; goto repeat;
case '#': flags |= SPECIAL; goto repeat;
case '0': flags |= ZEROPAD; goto repeat;
}
/* get field width */
field_width = -1;
if (isdigit(*fmt))
field_width = skip_atoi(&fmt);
else if (*fmt == '*') {
++fmt;
/* it's the next argument */
field_width = va_arg(args, int);
if (field_width < 0) {
field_width = -field_width;
flags |= LEFT;
}
}
/* get the precision */
precision = -1;
if (*fmt == '.') {
++fmt;
if (isdigit(*fmt))
precision = skip_atoi(&fmt);
else if (*fmt == '*') {
++fmt;
/* it's the next argument */
precision = va_arg(args, int);
}
if (precision < 0)
precision = 0;
}
/* get the conversion qualifier */
qualifier = -1;
if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
*fmt =='Z' || *fmt == 'z' || *fmt == 't') {
qualifier = *fmt;
++fmt;
if (qualifier == 'l' && *fmt == 'l') {
qualifier = 'L';
++fmt;
}
}
/* default base */
base = 10;
switch (*fmt) {
case 'c':
if (!(flags & LEFT)) {
while (--field_width > 0) {
if (str < end)
*str = ' ';
++str;
}
}
c = (unsigned char) va_arg(args, int);
if (str < end)
*str = c;
++str;
while (--field_width > 0) {
if (str < end)
*str = ' ';
++str;
}
continue;
case 's':
str = string(str, end, va_arg(args, char *), field_width, precision, flags);
continue;
case 'p':
str = pointer(fmt+1, str, end,
va_arg(args, void *),
field_width, precision, flags);
/* Skip all alphanumeric pointer suffixes */
while (isalnum(fmt[1]))
fmt++;
continue;
case 'n':
/* FIXME:
* What does C99 say about the overflow case here? */
if (qualifier == 'l') {
long * ip = va_arg(args, long *);
*ip = (str - buf);
} else if (qualifier == 'Z' || qualifier == 'z') {
size_t * ip = va_arg(args, size_t *);
*ip = (str - buf);
} else {
int * ip = va_arg(args, int *);
*ip = (str - buf);
}
continue;
case '%':
if (str < end)
*str = '%';
++str;
continue;
/* integer number formats - set up the flags and "break" */
case 'o':
base = 8;
break;
case 'x':
flags |= SMALL;
case 'X':
base = 16;
break;
case 'd':
case 'i':
flags |= SIGN;
case 'u':
break;
default:
if (str < end)
*str = '%';
++str;
if (*fmt) {
if (str < end)
*str = *fmt;
++str;
} else {
--fmt;
}
continue;
}
if (qualifier == 'L')
num = va_arg(args, long long);
else if (qualifier == 'l') {
num = va_arg(args, unsigned long);
if (flags & SIGN)
num = (signed long) num;
} else if (qualifier == 'Z' || qualifier == 'z') {
num = va_arg(args, size_t);
} else if (qualifier == 't') {
num = va_arg(args, ptrdiff_t);
} else if (qualifier == 'h') {
num = (unsigned short) va_arg(args, int);
if (flags & SIGN)
num = (signed short) num;
} else {
num = va_arg(args, unsigned int);
if (flags & SIGN)
num = (signed int) num;
}
str = number(str, end, num, base,
field_width, precision, flags);
}
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.
*
* Call this function if you are already dealing with a va_list.
* You probably want scnprintf() instead.
*/
int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
{
int i;
i=vsnprintf(buf,size,fmt,args);
return (i >= size) ? (size - 1) : i;
}
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.
*/
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 = vsnprintf(buf, size, fmt, args);
va_end(args);
return (i >= size) ? (size - 1) : 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.
*
* Call this function if you are already dealing with a va_list.
* You probably want sprintf() instead.
*/
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.
*/
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);
/**
* 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;
int qualifier;
int base;
int field_width;
int is_sign = 0;
while(*fmt && *str) {
/* skip any white space in format */
/* white space in format matchs any amount of
* white space, including none, in the input.
*/
if (isspace(*fmt)) {
while (isspace(*fmt))
++fmt;
while (isspace(*str))
++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 == '*') {
while (!isspace(*fmt) && *fmt)
fmt++;
while (!isspace(*str) && *str)
str++;
continue;
}
/* get field width */
field_width = -1;
if (isdigit(*fmt))
field_width = skip_atoi(&fmt);
/* get conversion qualifier */
qualifier = -1;
if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
*fmt == 'Z' || *fmt == 'z') {
qualifier = *fmt++;
if (unlikely(qualifier == *fmt)) {
if (qualifier == 'h') {
qualifier = 'H';
fmt++;
} else if (qualifier == 'l') {
qualifier = 'L';
fmt++;
}
}
}
base = 10;
is_sign = 0;
if (!*fmt || !*str)
break;
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 = INT_MAX;
/* first, skip leading white space in buffer */
while (isspace(*str))
str++;
/* now copy until next white space */
while (*str && !isspace(*str) && field_width--) {
*s++ = *str++;
}
*s = '\0';
num++;
}
continue;
case 'n':
/* return number of characters read so far */
{
int *i = (int *)va_arg(args,int*);
*i = str - buf;
}
continue;
case 'o':
base = 8;
break;
case 'x':
case 'X':
base = 16;
break;
case 'i':
base = 0;
case 'd':
is_sign = 1;
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.
*/
while (isspace(*str))
str++;
digit = *str;
if (is_sign && digit == '-')
digit = *(str + 1);
if (!digit
|| (base == 16 && !isxdigit(digit))
|| (base == 10 && !isdigit(digit))
|| (base == 8 && (!isdigit(digit) || digit > '7'))
|| (base == 0 && !isdigit(digit)))
break;
switch(qualifier) {
case 'H': /* that's 'hh' in format */
if (is_sign) {
signed char *s = (signed char *) va_arg(args,signed char *);
*s = (signed char) simple_strtol(str,&next,base);
} else {
unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
*s = (unsigned char) simple_strtoul(str, &next, base);
}
break;
case 'h':
if (is_sign) {
short *s = (short *) va_arg(args,short *);
*s = (short) simple_strtol(str,&next,base);
} else {
unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
*s = (unsigned short) simple_strtoul(str, &next, base);
}
break;
case 'l':
if (is_sign) {
long *l = (long *) va_arg(args,long *);
*l = simple_strtol(str,&next,base);
} else {
unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
*l = simple_strtoul(str,&next,base);
}
break;
case 'L':
if (is_sign) {
long long *l = (long long*) va_arg(args,long long *);
*l = simple_strtoll(str,&next,base);
} else {
unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
*l = simple_strtoull(str,&next,base);
}
break;
case 'Z':
case 'z':
{
size_t *s = (size_t*) va_arg(args,size_t*);
*s = (size_t) simple_strtoul(str,&next,base);
}
break;
default:
if (is_sign) {
int *i = (int *) va_arg(args, int*);
*i = (int) simple_strtol(str,&next,base);
} else {
unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
*i = (unsigned int) simple_strtoul(str,&next,base);
}
break;
}
num++;
if (!next)
break;
str = next;
}
/*
* Now we've come all the way through so either the input string or the
* format ended. In the former case, there can be a %n at the current
* position in the format that needs to be filled.
*/
if (*fmt == '%' && *(fmt + 1) == 'n') {
int *p = (int *)va_arg(args, int *);
*p = str - buf;
}
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);
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