On Wed, Feb 04, 2026 at 04:57:13PM +0300, Dmitry Antipov wrote:
> In '_parse_integer_limit()', adjust native integer arithmetic
> with near-to-overflow branch where 'check_mul_overflow()' and
> 'check_add_overflow()' are used to check whether an intermediate
> result goes out of range, and denote such a case with ULLONG_MAX,
> thus making the function more similar to standard C library's
> 'strtoull()'. Adjust comment to kernel-doc style as well.
...
> /*
> - * Check for overflow only if we are within range of
> - * it in the max base we support (16)
> + * Accumulate result if no overflow detected.
> + * Otherwise just consume valid characters.
> */
> - if (unlikely(res & (~0ull << 60))) {
> - if (res > div_u64(ULLONG_MAX - val, base))
> - rv |= KSTRTOX_OVERFLOW;
> + if (likely(res != ULLONG_MAX)) {
> + if (unlikely(res & (~0ull << 60))) {
> + /* We're close to possible overflow. */
> + if (check_mul_overflow(res, base, &tmp) ||
> + check_add_overflow(tmp, val, &res)) {
> + res = ULLONG_MAX;
> + rv |= KSTRTOX_OVERFLOW;
> + }
> + } else {
> + res = res * base + val;
> + }
> }
> - res = res * base + val;
> rv++;
> s++;
In case you would need a v6, we can leave some of the lines untouched if we
switch to for-loop instead of while, but it might make the for-loop quite long.
I'm okay with the current version, up to you to experiment and choose.
--
With Best Regards,
Andy Shevchenko
