diff options
Diffstat (limited to 'lib/vsprintf.c')
-rw-r--r-- | lib/vsprintf.c | 252 |
1 files changed, 145 insertions, 107 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index ac3f947..48ff9c3 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -383,13 +383,14 @@ enum format_type { }; struct printf_spec { - u8 type; /* format_type enum */ - u8 flags; /* flags to number() */ - u8 base; /* number base, 8, 10 or 16 only */ - u8 qualifier; /* number qualifier, one of 'hHlLtzZ' */ - s16 field_width; /* width of output field */ - s16 precision; /* # of digits/chars */ -}; + 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; +#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, @@ -402,6 +403,10 @@ char *number(char *buf, char *end, unsigned long long num, 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; + + BUILD_BUG_ON(sizeof(struct printf_spec) != 8); /* locase = 0 or 0x20. ORing digits or letters with 'locase' * produces same digits or (maybe lowercased) letters */ @@ -413,20 +418,20 @@ char *number(char *buf, char *end, unsigned long long num, if ((signed long long)num < 0) { sign = '-'; num = -(signed long long)num; - spec.field_width--; + field_width--; } else if (spec.flags & PLUS) { sign = '+'; - spec.field_width--; + field_width--; } else if (spec.flags & SPACE) { sign = ' '; - spec.field_width--; + field_width--; } } if (need_pfx) { if (spec.base == 16) - spec.field_width -= 2; + field_width -= 2; else if (!is_zero) - spec.field_width--; + field_width--; } /* generate full string in tmp[], in reverse order */ @@ -448,12 +453,12 @@ char *number(char *buf, char *end, unsigned long long num, } /* printing 100 using %2d gives "100", not "00" */ - if (i > spec.precision) - spec.precision = i; + if (i > precision) + precision = i; /* leading space padding */ - spec.field_width -= spec.precision; + field_width -= precision; if (!(spec.flags & (ZEROPAD | LEFT))) { - while (--spec.field_width >= 0) { + while (--field_width >= 0) { if (buf < end) *buf = ' '; ++buf; @@ -482,14 +487,14 @@ char *number(char *buf, char *end, unsigned long long num, if (!(spec.flags & LEFT)) { char c = ' ' + (spec.flags & ZEROPAD); BUILD_BUG_ON(' ' + ZEROPAD != '0'); - while (--spec.field_width >= 0) { + while (--field_width >= 0) { if (buf < end) *buf = c; ++buf; } } /* hmm even more zero padding? */ - while (i <= --spec.precision) { + while (i <= --precision) { if (buf < end) *buf = '0'; ++buf; @@ -501,7 +506,7 @@ char *number(char *buf, char *end, unsigned long long num, ++buf; } /* trailing space padding */ - while (--spec.field_width >= 0) { + while (--field_width >= 0) { if (buf < end) *buf = ' '; ++buf; @@ -511,37 +516,20 @@ char *number(char *buf, char *end, unsigned long long num, } static noinline_for_stack -char *string(char *buf, char *end, const char *s, struct printf_spec spec) +char *special_hex_number(char *buf, char *end, unsigned long long num, int size) { - int len, i; - - if ((unsigned long)s < PAGE_SIZE) - s = "(null)"; + struct printf_spec spec; - len = strnlen(s, spec.precision); - - if (!(spec.flags & LEFT)) { - while (len < spec.field_width--) { - if (buf < end) - *buf = ' '; - ++buf; - } - } - for (i = 0; i < len; ++i) { - if (buf < end) - *buf = *s; - ++buf; ++s; - } - while (len < spec.field_width--) { - if (buf < end) - *buf = ' '; - ++buf; - } + 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 buf; + return number(buf, end, num, spec); } -static void widen(char *buf, char *end, unsigned len, unsigned spaces) +static void move_right(char *buf, char *end, unsigned len, unsigned spaces) { size_t size; if (buf >= end) /* nowhere to put anything */ @@ -559,6 +547,56 @@ static void widen(char *buf, char *end, unsigned len, unsigned spaces) 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; +} + +static noinline_for_stack +char *string(char *buf, char *end, const char *s, struct printf_spec spec) +{ + int len = 0; + size_t lim = spec.precision; + + if ((unsigned long)s < PAGE_SIZE) + s = "(null)"; + + while (lim--) { + char c = *s++; + if (!c) + break; + if (buf < end) + *buf = c; + ++buf; + ++len; + } + return widen_string(buf, len, end, spec); +} + static noinline_for_stack char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, const char *fmt) @@ -600,20 +638,7 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp *buf = c; } rcu_read_unlock(); - if (n < spec.field_width) { - /* we want to pad the sucker */ - unsigned spaces = spec.field_width - n; - if (!(spec.flags & LEFT)) { - widen(buf - n, end, n, spaces); - return buf + spaces; - } - while (spaces--) { - if (buf < end) - *buf = ' '; - ++buf; - } - } - return buf; + return widen_string(buf, n, end, spec); } #ifdef CONFIG_BLOCK @@ -659,11 +684,7 @@ char *symbol_string(char *buf, char *end, void *ptr, return string(buf, end, sym, spec); #else - spec.field_width = 2 * sizeof(void *); - spec.flags |= SPECIAL | SMALL | ZEROPAD; - spec.base = 16; - - return number(buf, end, value, spec); + return special_hex_number(buf, end, value, sizeof(void *)); #endif } @@ -1324,40 +1345,45 @@ char *uuid_string(char *buf, char *end, const u8 *addr, return string(buf, end, uuid, spec); } -static -char *netdev_feature_string(char *buf, char *end, const u8 *addr, - struct printf_spec spec) +static noinline_for_stack +char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt) { - spec.flags |= SPECIAL | SMALL | ZEROPAD; - if (spec.field_width == -1) - spec.field_width = 2 + 2 * sizeof(netdev_features_t); - spec.base = 16; + unsigned long long num; + int size; - return number(buf, end, *(const netdev_features_t *)addr, spec); + switch (fmt[1]) { + case 'F': + num = *(const netdev_features_t *)addr; + size = sizeof(netdev_features_t); + break; + default: + num = (unsigned long)addr; + size = sizeof(unsigned long); + break; + } + + return special_hex_number(buf, end, num, size); } static noinline_for_stack -char *address_val(char *buf, char *end, const void *addr, - struct printf_spec spec, const char *fmt) +char *address_val(char *buf, char *end, const void *addr, const char *fmt) { unsigned long long num; - - spec.flags |= SPECIAL | SMALL | ZEROPAD; - spec.base = 16; + int size; switch (fmt[1]) { case 'd': num = *(const dma_addr_t *)addr; - spec.field_width = sizeof(dma_addr_t) * 2 + 2; + size = sizeof(dma_addr_t); break; case 'p': default: num = *(const phys_addr_t *)addr; - spec.field_width = sizeof(phys_addr_t) * 2 + 2; + size = sizeof(phys_addr_t); break; } - return number(buf, end, num, spec); + return special_hex_number(buf, end, num, size); } static noinline_for_stack @@ -1376,10 +1402,7 @@ char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, #ifdef CONFIG_COMMON_CLK return string(buf, end, __clk_get_name(clk), spec); #else - spec.base = 16; - spec.field_width = sizeof(unsigned long) * 2 + 2; - spec.flags |= SPECIAL | SMALL | ZEROPAD; - return number(buf, end, (unsigned long)clk, spec); + return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long)); #endif } } @@ -1609,13 +1632,9 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, break; case 'N': - switch (fmt[1]) { - case 'F': - return netdev_feature_string(buf, end, ptr, spec); - } - break; + return netdev_bits(buf, end, ptr, fmt); case 'a': - return address_val(buf, end, ptr, spec, fmt); + return address_val(buf, end, ptr, fmt); case 'd': return dentry_name(buf, end, ptr, spec, fmt); case 'C': @@ -1664,6 +1683,7 @@ 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) { @@ -1746,16 +1766,16 @@ precision: qualifier: /* get the conversion qualifier */ - spec->qualifier = -1; + qualifier = 0; if (*fmt == 'h' || _tolower(*fmt) == 'l' || _tolower(*fmt) == 'z' || *fmt == 't') { - spec->qualifier = *fmt++; - if (unlikely(spec->qualifier == *fmt)) { - if (spec->qualifier == 'l') { - spec->qualifier = 'L'; + qualifier = *fmt++; + if (unlikely(qualifier == *fmt)) { + if (qualifier == 'l') { + qualifier = 'L'; ++fmt; - } else if (spec->qualifier == 'h') { - spec->qualifier = 'H'; + } else if (qualifier == 'h') { + qualifier = 'H'; ++fmt; } } @@ -1812,19 +1832,19 @@ qualifier: return fmt - start; } - if (spec->qualifier == 'L') + if (qualifier == 'L') spec->type = FORMAT_TYPE_LONG_LONG; - else if (spec->qualifier == 'l') { + else if (qualifier == 'l') { BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); - } else if (_tolower(spec->qualifier) == 'z') { + } else if (_tolower(qualifier) == 'z') { spec->type = FORMAT_TYPE_SIZE_T; - } else if (spec->qualifier == 't') { + } else if (qualifier == 't') { spec->type = FORMAT_TYPE_PTRDIFF; - } else if (spec->qualifier == 'H') { + } else if (qualifier == 'H') { BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); - } else if (spec->qualifier == 'h') { + } else if (qualifier == 'h') { BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); } else { @@ -1835,6 +1855,24 @@ qualifier: 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 @@ -1902,11 +1940,11 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) } case FORMAT_TYPE_WIDTH: - spec.field_width = va_arg(args, int); + set_field_width(&spec, va_arg(args, int)); break; case FORMAT_TYPE_PRECISION: - spec.precision = va_arg(args, int); + set_precision(&spec, va_arg(args, int)); break; case FORMAT_TYPE_CHAR: { @@ -2346,11 +2384,11 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) } case FORMAT_TYPE_WIDTH: - spec.field_width = get_arg(int); + set_field_width(&spec, get_arg(int)); break; case FORMAT_TYPE_PRECISION: - spec.precision = get_arg(int); + set_precision(&spec, get_arg(int)); break; case FORMAT_TYPE_CHAR: { |