diff options
Diffstat (limited to 'util/cutils.c')
| -rw-r--r-- | util/cutils.c | 90 |
1 files changed, 68 insertions, 22 deletions
diff --git a/util/cutils.c b/util/cutils.c index bde2da59bd..25373198ad 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -194,15 +194,19 @@ static int64_t suffix_mul(char suffix, int64_t unit) * - 12345 - decimal, scale determined by @default_suffix and @unit * - 12345{bBkKmMgGtTpPeE} - decimal, scale determined by suffix and @unit * - 12345.678{kKmMgGtTpPeE} - decimal, scale determined by suffix, and - * fractional portion is truncated to byte + * fractional portion is truncated to byte, either side of . may be empty * - 0x7fEE - hexadecimal, unit determined by @default_suffix * * The following are intentionally not supported - * - hex with scaling suffix, such as 0x20M - * - octal, such as 08 - * - fractional hex, such as 0x1.8 - * - negative values, including -0 - * - floating point exponents, such as 1e3 + * - hex with scaling suffix, such as 0x20M or 0x1p3 (both fail with + * -EINVAL), while 0x1b is 27 (not 1 with byte scale) + * - octal, such as 08 (parsed as decimal instead) + * - binary, such as 0b1000 (parsed as 0b with trailing garbage "1000") + * - fractional hex, such as 0x1.8 (parsed as 0 with trailing garbage "x1.8") + * - negative values, including -0 (fail with -ERANGE) + * - floating point exponents, such as 1e3 (parsed as 1e with trailing + * garbage "3") or 0x1p3 (rejected as hex with scaling suffix) + * - non-finite values, such as inf or NaN (fail with -EINVAL) * * The end pointer will be returned in *end, if not NULL. If there is * no fraction, the input can be decimal or hexadecimal; if there is a @@ -221,17 +225,17 @@ static int do_strtosz(const char *nptr, const char **end, uint64_t *result) { int retval; - const char *endptr, *f; + const char *endptr; unsigned char c; - uint64_t val, valf = 0; + uint64_t val = 0, valf = 0; int64_t mul; /* Parse integral portion as decimal. */ retval = parse_uint(nptr, &endptr, 10, &val); - if (retval) { + if (retval == -ERANGE || !nptr) { goto out; } - if (val == 0 && (*endptr == 'x' || *endptr == 'X')) { + if (retval == 0 && val == 0 && (*endptr == 'x' || *endptr == 'X')) { /* Input looks like hex; reparse, and insist on no fraction or suffix. */ retval = qemu_strtou64(nptr, &endptr, 16, &val); if (retval) { @@ -242,27 +246,69 @@ static int do_strtosz(const char *nptr, const char **end, retval = -EINVAL; goto out; } - } else if (*endptr == '.') { + } else if (*endptr == '.' || (endptr == nptr && strchr(nptr, '.'))) { /* * Input looks like a fraction. Make sure even 1.k works - * without fractional digits. If we see an exponent, treat - * the entire input as invalid instead. + * without fractional digits. strtod tries to treat 'e' as an + * exponent, but we want to treat it as a scaling suffix; + * doing this requires modifying a copy of the fraction. */ - double fraction; + double fraction = 0.0; - f = endptr; - retval = qemu_strtod_finite(f, &endptr, &fraction); - if (retval) { + if (retval == 0 && *endptr == '.' && !isdigit(endptr[1])) { + /* If we got here, we parsed at least one digit already. */ endptr++; - } else if (memchr(f, 'e', endptr - f) || memchr(f, 'E', endptr - f)) { - endptr = nptr; - retval = -EINVAL; - goto out; } else { - /* Extract into a 64-bit fixed-point fraction. */ + char *e; + const char *tail; + g_autofree char *copy = g_strdup(endptr); + + e = strchr(copy, 'e'); + if (e) { + *e = '\0'; + } + e = strchr(copy, 'E'); + if (e) { + *e = '\0'; + } + /* + * If this is a floating point, we are guaranteed that '.' + * appears before any possible digits in copy. If it is + * not a floating point, strtod will fail. Either way, + * there is now no exponent in copy, so if it parses, we + * know 0.0 <= abs(result) <= 1.0 (after rounding), and + * ERANGE is only possible on underflow which is okay. + */ + retval = qemu_strtod_finite(copy, &tail, &fraction); + endptr += tail - copy; + if (signbit(fraction)) { + retval = -ERANGE; + goto out; + } + } + + /* Extract into a 64-bit fixed-point fraction. */ + if (fraction == 1.0) { + if (val == UINT64_MAX) { + retval = -ERANGE; + goto out; + } + val++; + } else if (retval == -ERANGE) { + /* See comments above about underflow */ + valf = 1; + retval = 0; + } else { + /* We want non-zero valf for any non-zero fraction */ valf = (uint64_t)(fraction * 0x1p64); + if (valf == 0 && fraction > 0.0) { + valf = 1; + } } } + if (retval) { + goto out; + } c = *endptr; mul = suffix_mul(c, unit); if (mul > 0) { |