diff options
| -rw-r--r-- | lib/vsprintf.c | 133 |
1 files changed, 54 insertions, 79 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 123e58724262..9142c8c76f82 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -2566,7 +2566,7 @@ static noinline_for_stack struct fmt format_decode(struct fmt fmt, struct printf_spec *spec) { const char *start = fmt.str; - char flag, qualifier; + char flag; /* we finished early by reading the field width */ if (fmt.state == FORMAT_STATE_WIDTH) { @@ -2637,96 +2637,71 @@ precision: } qualifier: - /* get the conversion qualifier */ - qualifier = 0; - if (*fmt.str == 'h' || _tolower(*fmt.str) == 'l' || - *fmt.str == 'z' || *fmt.str == 't') { - qualifier = *fmt.str++; - if (unlikely(qualifier == *fmt.str)) { - if (qualifier == 'l') { - qualifier = 'L'; - fmt.str++; - } else if (qualifier == 'h') { - qualifier = 'H'; - fmt.str++; - } - } - } - - /* default base */ + /* Set up default numeric format */ spec->base = 10; - switch (*fmt.str) { - case 'c': - fmt.state = FORMAT_STATE_CHAR; - fmt.str++; - return fmt; - - case 's': - fmt.state = FORMAT_STATE_STR; - fmt.str++; - return fmt; - - case 'p': - fmt.state = FORMAT_STATE_PTR; - fmt.str++; - return fmt; - - case '%': - fmt.state = FORMAT_STATE_PERCENT_CHAR; - fmt.str++; - return fmt; - - /* 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; + fmt.state = FORMAT_STATE_SIZE(int); + static const struct format_state { + unsigned char state; + unsigned char flags_or_double_state; + unsigned char modifier; + unsigned char base; + } lookup_state[256] = { + // Qualifiers + ['l'] = { FORMAT_STATE_SIZE(long), FORMAT_STATE_SIZE(long long), 1 }, + ['L'] = { FORMAT_STATE_SIZE(long long), 0, 1 }, + ['h'] = { FORMAT_STATE_SIZE(short), FORMAT_STATE_SIZE(char), 1 }, + ['H'] = { FORMAT_STATE_SIZE(char), 0, 1 }, // Questionable, historic + ['z'] = { FORMAT_STATE_SIZE(size_t), 0, 1 }, + ['t'] = { FORMAT_STATE_SIZE(ptrdiff_t), 0, 1 }, + + // Non-numeric formats + ['c'] = { FORMAT_STATE_CHAR }, + ['s'] = { FORMAT_STATE_STR }, + ['p'] = { FORMAT_STATE_PTR }, + ['%'] = { FORMAT_STATE_PERCENT_CHAR }, + + // Numerics + ['o'] = { 0, 0, 0, 8 }, + ['x'] = { 0, SMALL, 0, 16 }, + ['X'] = { 0, 0, 0, 16 }, + ['d'] = { 0, SIGN, 0, 10 }, + ['i'] = { 0, SIGN, 0, 10 }, + ['u'] = { 0, 0, 0, 10, }, - 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.str); - fmt.state = FORMAT_STATE_INVALID; + const struct format_state *p = lookup_state + (u8)*fmt.str; + if (p->modifier) { + fmt.state = p->state; + if (p->flags_or_double_state && fmt.str[0] == fmt.str[1]) { + fmt.state = p->flags_or_double_state; + fmt.str++; + } + fmt.str++; + p = lookup_state + *fmt.str; + if (unlikely(p->modifier)) + goto invalid; + } + if (p->base) { + spec->base = p->base; + spec->flags |= p->flags_or_double_state; + fmt.str++; return fmt; } - - if (qualifier == 'L') - fmt.state = FORMAT_STATE_SIZE(long long); - else if (qualifier == 'l') { - fmt.state = FORMAT_STATE_SIZE(long); - } else if (qualifier == 'z') { - fmt.state = FORMAT_STATE_SIZE(size_t); - } else if (qualifier == 't') { - fmt.state = FORMAT_STATE_SIZE(ptrdiff_t); - } else if (qualifier == 'H') { - fmt.state = FORMAT_STATE_SIZE(char); - } else if (qualifier == 'h') { - fmt.state = FORMAT_STATE_SIZE(short); - } else { - fmt.state = FORMAT_STATE_SIZE(int); + if (p->state) { + fmt.state = p->state; + fmt.str++; + return fmt; } - fmt.str++; +invalid: + WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt.str); + fmt.state = FORMAT_STATE_INVALID; return fmt; } |