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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/firmware/efi/libstub/vsprintf.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/libstub/vsprintf.c')
-rw-r--r-- | drivers/firmware/efi/libstub/vsprintf.c | 564 |
1 files changed, 564 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/vsprintf.c b/drivers/firmware/efi/libstub/vsprintf.c new file mode 100644 index 000000000..71c71c222 --- /dev/null +++ b/drivers/firmware/efi/libstub/vsprintf.c @@ -0,0 +1,564 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Oh, it's a waste of space, but oh-so-yummy for debugging. + */ + +#include <linux/stdarg.h> + +#include <linux/compiler.h> +#include <linux/ctype.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/string.h> +#include <linux/types.h> + +static +int skip_atoi(const char **s) +{ + int i = 0; + + while (isdigit(**s)) + i = i * 10 + *((*s)++) - '0'; + return i; +} + +/* + * put_dec_full4 handles numbers in the range 0 <= r < 10000. + * The multiplier 0xccd is round(2^15/10), and the approximation + * r/10 == (r * 0xccd) >> 15 is exact for all r < 16389. + */ +static +void put_dec_full4(char *end, unsigned int r) +{ + int i; + + for (i = 0; i < 3; i++) { + unsigned int q = (r * 0xccd) >> 15; + *--end = '0' + (r - q * 10); + r = q; + } + *--end = '0' + r; +} + +/* put_dec is copied from lib/vsprintf.c with small modifications */ + +/* + * 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 +unsigned int put_dec_helper4(char *end, unsigned int x) +{ + unsigned int q = (x * 0x346DC5D7ULL) >> 43; + + put_dec_full4(end, 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 *end, unsigned long long n) +{ + unsigned int d3, d2, d1, q, h; + char *p = end; + + d1 = ((unsigned int)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 + ((unsigned int)n & 0xffff); + q = put_dec_helper4(p, q); + p -= 4; + + q += 7671 * d3 + 9496 * d2 + 6 * d1; + q = put_dec_helper4(p, q); + p -= 4; + + q += 4749 * d3 + 42 * d2; + q = put_dec_helper4(p, q); + p -= 4; + + q += 281 * d3; + q = put_dec_helper4(p, q); + p -= 4; + + put_dec_full4(p, q); + p -= 4; + + /* strip off the extra 0's we printed */ + while (p < end && *p == '0') + ++p; + + return p; +} + +static +char *number(char *end, unsigned long long num, int base, char locase) +{ + /* + * locase = 0 or 0x20. ORing digits or letters with 'locase' + * produces same digits or (maybe lowercased) letters + */ + + /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ + static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ + + switch (base) { + case 10: + if (num != 0) + end = put_dec(end, num); + break; + case 8: + for (; num != 0; num >>= 3) + *--end = '0' + (num & 07); + break; + case 16: + for (; num != 0; num >>= 4) + *--end = digits[num & 0xf] | locase; + break; + default: + unreachable(); + } + + return end; +} + +#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 */ +#define WIDE 128 /* UTF-16 string */ + +static +int get_flags(const char **fmt) +{ + int flags = 0; + + do { + switch (**fmt) { + case '-': + flags |= LEFT; + break; + case '+': + flags |= PLUS; + break; + case ' ': + flags |= SPACE; + break; + case '#': + flags |= SPECIAL; + break; + case '0': + flags |= ZEROPAD; + break; + default: + return flags; + } + ++(*fmt); + } while (1); +} + +static +int get_int(const char **fmt, va_list *ap) +{ + if (isdigit(**fmt)) + return skip_atoi(fmt); + if (**fmt == '*') { + ++(*fmt); + /* it's the next argument */ + return va_arg(*ap, int); + } + return 0; +} + +static +unsigned long long get_number(int sign, int qualifier, va_list *ap) +{ + if (sign) { + switch (qualifier) { + case 'L': + return va_arg(*ap, long long); + case 'l': + return va_arg(*ap, long); + case 'h': + return (short)va_arg(*ap, int); + case 'H': + return (signed char)va_arg(*ap, int); + default: + return va_arg(*ap, int); + }; + } else { + switch (qualifier) { + case 'L': + return va_arg(*ap, unsigned long long); + case 'l': + return va_arg(*ap, unsigned long); + case 'h': + return (unsigned short)va_arg(*ap, int); + case 'H': + return (unsigned char)va_arg(*ap, int); + default: + return va_arg(*ap, unsigned int); + } + } +} + +static +char get_sign(long long *num, int flags) +{ + if (!(flags & SIGN)) + return 0; + if (*num < 0) { + *num = -(*num); + return '-'; + } + if (flags & PLUS) + return '+'; + if (flags & SPACE) + return ' '; + return 0; +} + +static +size_t utf16s_utf8nlen(const u16 *s16, size_t maxlen) +{ + size_t len, clen; + + for (len = 0; len < maxlen && *s16; len += clen) { + u16 c0 = *s16++; + + /* First, get the length for a BMP character */ + clen = 1 + (c0 >= 0x80) + (c0 >= 0x800); + if (len + clen > maxlen) + break; + /* + * If this is a high surrogate, and we're already at maxlen, we + * can't include the character if it's a valid surrogate pair. + * Avoid accessing one extra word just to check if it's valid + * or not. + */ + if ((c0 & 0xfc00) == 0xd800) { + if (len + clen == maxlen) + break; + if ((*s16 & 0xfc00) == 0xdc00) { + ++s16; + ++clen; + } + } + } + + return len; +} + +static +u32 utf16_to_utf32(const u16 **s16) +{ + u16 c0, c1; + + c0 = *(*s16)++; + /* not a surrogate */ + if ((c0 & 0xf800) != 0xd800) + return c0; + /* invalid: low surrogate instead of high */ + if (c0 & 0x0400) + return 0xfffd; + c1 = **s16; + /* invalid: missing low surrogate */ + if ((c1 & 0xfc00) != 0xdc00) + return 0xfffd; + /* valid surrogate pair */ + ++(*s16); + return (0x10000 - (0xd800 << 10) - 0xdc00) + (c0 << 10) + c1; +} + +#define PUTC(c) \ +do { \ + if (pos < size) \ + buf[pos] = (c); \ + ++pos; \ +} while (0); + +int vsnprintf(char *buf, size_t size, const char *fmt, va_list ap) +{ + /* The maximum space required is to print a 64-bit number in octal */ + char tmp[(sizeof(unsigned long long) * 8 + 2) / 3]; + char *tmp_end = &tmp[ARRAY_SIZE(tmp)]; + long long num; + int base; + const char *s; + size_t len, pos; + char sign; + + 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', 'hh', 'l' or 'll' for integer fields */ + + va_list args; + + /* + * We want to pass our input va_list to helper functions by reference, + * but there's an annoying edge case. If va_list was originally passed + * to us by value, we could just pass &ap down to the helpers. This is + * the case on, for example, X86_32. + * However, on X86_64 (and possibly others), va_list is actually a + * size-1 array containing a structure. Our function parameter ap has + * decayed from T[1] to T*, and &ap has type T** rather than T(*)[1], + * which is what will be expected by a function taking a va_list * + * parameter. + * One standard way to solve this mess is by creating a copy in a local + * variable of type va_list and then passing a pointer to that local + * copy instead, which is what we do here. + */ + va_copy(args, ap); + + for (pos = 0; *fmt; ++fmt) { + if (*fmt != '%' || *++fmt == '%') { + PUTC(*fmt); + continue; + } + + /* process flags */ + flags = get_flags(&fmt); + + /* get field width */ + field_width = get_int(&fmt, &args); + if (field_width < 0) { + field_width = -field_width; + flags |= LEFT; + } + + if (flags & LEFT) + flags &= ~ZEROPAD; + + /* get the precision */ + precision = -1; + if (*fmt == '.') { + ++fmt; + precision = get_int(&fmt, &args); + if (precision >= 0) + flags &= ~ZEROPAD; + } + + /* get the conversion qualifier */ + qualifier = -1; + if (*fmt == 'h' || *fmt == 'l') { + qualifier = *fmt; + ++fmt; + if (qualifier == *fmt) { + qualifier -= 'a'-'A'; + ++fmt; + } + } + + sign = 0; + + switch (*fmt) { + case 'c': + flags &= LEFT; + s = tmp; + if (qualifier == 'l') { + ((u16 *)tmp)[0] = (u16)va_arg(args, unsigned int); + ((u16 *)tmp)[1] = L'\0'; + precision = INT_MAX; + goto wstring; + } else { + tmp[0] = (unsigned char)va_arg(args, int); + precision = len = 1; + } + goto output; + + case 's': + flags &= LEFT; + if (precision < 0) + precision = INT_MAX; + s = va_arg(args, void *); + if (!s) + s = precision < 6 ? "" : "(null)"; + else if (qualifier == 'l') { + wstring: + flags |= WIDE; + precision = len = utf16s_utf8nlen((const u16 *)s, precision); + goto output; + } + precision = len = strnlen(s, precision); + goto output; + + /* integer number formats - set up the flags and "break" */ + case 'o': + base = 8; + break; + + case 'p': + if (precision < 0) + precision = 2 * sizeof(void *); + fallthrough; + case 'x': + flags |= SMALL; + fallthrough; + case 'X': + base = 16; + break; + + case 'd': + case 'i': + flags |= SIGN; + fallthrough; + case 'u': + flags &= ~SPECIAL; + base = 10; + break; + + default: + /* + * Bail out if the conversion specifier is invalid. + * There's probably a typo in the format string and the + * remaining specifiers are unlikely to match up with + * the arguments. + */ + goto fail; + } + if (*fmt == 'p') { + num = (unsigned long)va_arg(args, void *); + } else { + num = get_number(flags & SIGN, qualifier, &args); + } + + sign = get_sign(&num, flags); + if (sign) + --field_width; + + s = number(tmp_end, num, base, flags & SMALL); + len = tmp_end - s; + /* default precision is 1 */ + if (precision < 0) + precision = 1; + /* precision is minimum number of digits to print */ + if (precision < len) + precision = len; + if (flags & SPECIAL) { + /* + * For octal, a leading 0 is printed only if necessary, + * i.e. if it's not already there because of the + * precision. + */ + if (base == 8 && precision == len) + ++precision; + /* + * For hexadecimal, the leading 0x is skipped if the + * output is empty, i.e. both the number and the + * precision are 0. + */ + if (base == 16 && precision > 0) + field_width -= 2; + else + flags &= ~SPECIAL; + } + /* + * For zero padding, increase the precision to fill the field + * width. + */ + if ((flags & ZEROPAD) && field_width > precision) + precision = field_width; + +output: + /* Calculate the padding necessary */ + field_width -= precision; + /* Leading padding with ' ' */ + if (!(flags & LEFT)) + while (field_width-- > 0) + PUTC(' '); + /* sign */ + if (sign) + PUTC(sign); + /* 0x/0X for hexadecimal */ + if (flags & SPECIAL) { + PUTC('0'); + PUTC( 'X' | (flags & SMALL)); + } + /* Zero padding and excess precision */ + while (precision-- > len) + PUTC('0'); + /* Actual output */ + if (flags & WIDE) { + const u16 *ws = (const u16 *)s; + + while (len-- > 0) { + u32 c32 = utf16_to_utf32(&ws); + u8 *s8; + size_t clen; + + if (c32 < 0x80) { + PUTC(c32); + continue; + } + + /* Number of trailing octets */ + clen = 1 + (c32 >= 0x800) + (c32 >= 0x10000); + + len -= clen; + s8 = (u8 *)&buf[pos]; + + /* Avoid writing partial character */ + PUTC('\0'); + pos += clen; + if (pos >= size) + continue; + + /* Set high bits of leading octet */ + *s8 = (0xf00 >> 1) >> clen; + /* Write trailing octets in reverse order */ + for (s8 += clen; clen; --clen, c32 >>= 6) + *s8-- = 0x80 | (c32 & 0x3f); + /* Set low bits of leading octet */ + *s8 |= c32; + } + } else { + while (len-- > 0) + PUTC(*s++); + } + /* Trailing padding with ' ' */ + while (field_width-- > 0) + PUTC(' '); + } +fail: + va_end(args); + + if (size) + buf[min(pos, size-1)] = '\0'; + + return pos; +} + +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; +} |