Re: [PATCH bpf-next v3 0/4] bpf: replace min/max fields with struct cnum{32,64}

Eduard Zingerman
2026-04-25T10:05:36Z

On Fri, 2026-04-24 at 15:52 -0700, Eduard Zingerman wrote:
> This RFC replaces s64, u64, s32, u32 scalar range domains tracked by
> verifier by a pair of circular numbers (cnums): one for 64-bit domain
> and another for 32-bit domain. Each cnum represents a range as a
> single arc on the circular number line, from which signed and unsigned
> bounds are derived on demand. See also wrapped intervals
> representation as in [1].
>
> The use of such representation simplifies arithmetic and conditions
> handling in verifier.c and allows to express 32 <-> 64 bit deductions
> in a more mathematically rigorous way.
>
> [1] https://jorgenavas.github.io/papers/ACM-TOPLAS-wrapped.pdf

Uh-oh. range_within() needs an update. …