diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/cutils.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/util/cutils.c b/util/cutils.c index 5887e74414..9b6ce9179c 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -391,6 +391,9 @@ static int check_strtox_error(const char *nptr, char *ep, * and return -ERANGE. * * Else store the converted value in @result, and return zero. + * + * This matches the behavior of strtol() on 32-bit platforms, even on + * platforms where long is 64-bits. */ int qemu_strtoi(const char *nptr, const char **endptr, int base, int *result) @@ -443,13 +446,15 @@ int qemu_strtoi(const char *nptr, const char **endptr, int base, * * Note that a number with a leading minus sign gets converted without * the minus sign, checked for overflow (see above), then negated (in - * @result's type). This is exactly how strtoul() works. + * @result's type). This matches the behavior of strtoul() on 32-bit + * platforms, even on platforms where long is 64-bits. */ int qemu_strtoui(const char *nptr, const char **endptr, int base, unsigned int *result) { char *ep; - long long lresult; + unsigned long long lresult; + bool neg; assert((unsigned) base <= 36 && base != 1); if (!nptr) { @@ -466,14 +471,22 @@ int qemu_strtoui(const char *nptr, const char **endptr, int base, if (errno == ERANGE) { *result = -1; } else { + /* + * Note that platforms with 32-bit strtoul only accept input + * in the range [-4294967295, 4294967295]; but we used 64-bit + * strtoull which wraps -18446744073709551615 to 1 instead of + * declaring overflow. So we must check if '-' was parsed, + * and if so, undo the negation before doing our bounds check. + */ + neg = memchr(nptr, '-', ep - nptr) != NULL; + if (neg) { + lresult = -lresult; + } if (lresult > UINT_MAX) { *result = UINT_MAX; errno = ERANGE; - } else if (lresult < INT_MIN) { - *result = UINT_MAX; - errno = ERANGE; } else { - *result = lresult; + *result = neg ? -lresult : lresult; } } return check_strtox_error(nptr, ep, endptr, lresult == 0, errno); |