X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fvsprintf.c;h=6021757a449663074cded737138d31acd83da325;hb=d973664992d814d93db161b28c0cc9a4c7e68f42;hp=e4e9031dd9c38709b82fd7de2da931ada0cec248;hpb=343b0597297c3190647854881c087c01faf40a6f;p=linux-2.6 diff --git a/lib/vsprintf.c b/lib/vsprintf.c index e4e9031dd9..6021757a44 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -23,8 +23,12 @@ #include #include +#include /* for PAGE_SIZE */ #include +/* 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 @@ -40,17 +44,17 @@ unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base) if (*cp == '0') { base = 8; cp++; - if ((toupper(*cp) == 'X') && isxdigit(cp[1])) { + if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) { cp++; base = 16; } } } else if (base == 16) { - if (cp[0] == '0' && toupper(cp[1]) == 'X') + if (cp[0] == '0' && TOLOWER(cp[1]) == 'x') cp += 2; } while (isxdigit(*cp) && - (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) { + (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) { result = result*base + value; cp++; } @@ -91,17 +95,17 @@ unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base) if (*cp == '0') { base = 8; cp++; - if ((toupper(*cp) == 'X') && isxdigit(cp[1])) { + if ((TOLOWER(*cp) == 'x') && isxdigit(cp[1])) { cp++; base = 16; } } } else if (base == 16) { - if (cp[0] == '0' && toupper(cp[1]) == 'X') + if (cp[0] == '0' && TOLOWER(cp[1]) == 'x') cp += 2; } - while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp) - ? toupper(*cp) : *cp)-'A'+10) < base) { + while (isxdigit(*cp) + && (value = isdigit(*cp) ? *cp-'0' : TOLOWER(*cp)-'a'+10) < base) { result = result*base + value; cp++; } @@ -125,6 +129,129 @@ long long simple_strtoll(const char *cp,char **endp,unsigned int 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; @@ -134,28 +261,127 @@ static int skip_atoi(const char **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 + * 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 SPECIAL 32 /* 0x */ -#define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */ +#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) +static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type) { - char c,sign,tmp[66]; - const char *digits; - static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz"; - static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; + /* 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; - digits = (type & LARGE) ? large_digits : small_digits; + /* 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; - if (base < 2 || base > 36) - return NULL; - c = (type & ZEROPAD) ? '0' : ' '; sign = 0; if (type & SIGN) { if ((signed long long) num < 0) { @@ -170,65 +396,86 @@ static char * number(char * buf, char * end, unsigned long long num, int base, i size--; } } - if (type & SPECIAL) { + if (need_pfx) { + size--; if (base == 16) - size -= 2; - else if (base == 8) size--; } + + /* generate full string in tmp[], in reverse order */ i = 0; if (num == 0) - tmp[i++]='0'; - else while (num != 0) - tmp[i++] = digits[do_div(num,base)]; + 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) + if (!(type & (ZEROPAD+LEFT))) { + while(--size >= 0) { + if (buf < end) *buf = ' '; ++buf; } } + /* sign */ if (sign) { - if (buf <= end) + if (buf < end) *buf = sign; ++buf; } - if (type & SPECIAL) { - if (base==8) { - if (buf <= end) - *buf = '0'; - ++buf; - } else if (base==16) { - if (buf <= end) - *buf = '0'; - ++buf; - if (buf <= end) - *buf = digits[33]; + /* "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)) { - while (size-- > 0) { - if (buf <= end) + char c = (type & ZEROPAD) ? '0' : ' '; + while (--size >= 0) { + if (buf < end) *buf = c; ++buf; } } - while (i < precision--) { - if (buf <= end) + /* hmm even more zero padding? */ + while (i <= --precision) { + if (buf < end) *buf = '0'; ++buf; } - while (i-- > 0) { - if (buf <= end) + /* actual digits of result */ + while (--i >= 0) { + if (buf < end) *buf = tmp[i]; ++buf; } - while (size-- > 0) { - if (buf <= end) + /* trailing space padding */ + while (--size >= 0) { + if (buf < end) *buf = ' '; ++buf; } @@ -246,12 +493,12 @@ static char * number(char * buf, char * end, unsigned long long num, int base, i * 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 + * (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. + * You probably want snprintf() instead. */ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) { @@ -271,26 +518,28 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) /* 'z' changed to 'Z' --davidm 1/25/99 */ /* 't' added for ptrdiff_t */ - /* Reject out-of-range values early */ + /* 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 int warn = 1; + static char warn = 1; WARN_ON(warn); warn = 0; return 0; } str = buf; - end = buf + size - 1; + end = buf + size; - if (end < buf - 1) { - end = ((void *) -1); - size = end - buf + 1; + /* Make sure end is always >= buf */ + if (end < buf) { + end = ((void *)-1); + size = end - buf; } for (; *fmt ; ++fmt) { if (*fmt != '%') { - if (str <= end) + if (str < end) *str = *fmt; ++str; continue; @@ -356,17 +605,17 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) case 'c': if (!(flags & LEFT)) { while (--field_width > 0) { - if (str <= end) + if (str < end) *str = ' '; ++str; } } c = (unsigned char) va_arg(args, int); - if (str <= end) + if (str < end) *str = c; ++str; while (--field_width > 0) { - if (str <= end) + if (str < end) *str = ' '; ++str; } @@ -381,24 +630,25 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) if (!(flags & LEFT)) { while (len < field_width--) { - if (str <= end) + if (str < end) *str = ' '; ++str; } } for (i = 0; i < len; ++i) { - if (str <= end) + if (str < end) *str = *s; ++str; ++s; } while (len < field_width--) { - if (str <= end) + if (str < end) *str = ' '; ++str; } continue; case 'p': + flags |= SMALL; if (field_width == -1) { field_width = 2*sizeof(void *); flags |= ZEROPAD; @@ -425,7 +675,7 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) continue; case '%': - if (str <= end) + if (str < end) *str = '%'; ++str; continue; @@ -435,9 +685,9 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) base = 8; break; - case 'X': - flags |= LARGE; case 'x': + flags |= SMALL; + case 'X': base = 16; break; @@ -448,11 +698,11 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) break; default: - if (str <= end) + if (str < end) *str = '%'; ++str; if (*fmt) { - if (str <= end) + if (str < end) *str = *fmt; ++str; } else { @@ -482,14 +732,13 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) str = number(str, end, num, base, field_width, precision, flags); } - if (str <= end) - *str = '\0'; - else if (size > 0) - /* don't write out a null byte if the buf size is zero */ - *end = '\0'; - /* the trailing null byte doesn't count towards the total - * ++str; - */ + 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; } @@ -507,7 +756,7 @@ EXPORT_SYMBOL(vsnprintf); * returns 0. * * Call this function if you are already dealing with a va_list. - * You probably want scnprintf instead. + * You probably want scnprintf() instead. */ int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) { @@ -552,8 +801,7 @@ EXPORT_SYMBOL(snprintf); * @...: 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. If the return is - * greater than or equal to @size, the resulting string is truncated. + * the trailing '\0'. If @size is <= 0 the function returns 0. */ int scnprintf(char * buf, size_t size, const char *fmt, ...) @@ -575,11 +823,11 @@ EXPORT_SYMBOL(scnprintf); * @args: Arguments for the format string * * The function returns the number of characters written - * into @buf. Use vsnprintf or vscnprintf in order to avoid + * 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. + * You probably want sprintf() instead. */ int vsprintf(char *buf, const char *fmt, va_list args) { @@ -595,7 +843,7 @@ EXPORT_SYMBOL(vsprintf); * @...: Arguments for the format string * * The function returns the number of characters written - * into @buf. Use snprintf or scnprintf in order to avoid + * into @buf. Use snprintf() or scnprintf() in order to avoid * buffer overflows. */ int sprintf(char * buf, const char *fmt, ...) @@ -824,6 +1072,17 @@ int vsscanf(const char * buf, const char * fmt, va_list args) 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; }