Re: [PATCH bpf-next 09/36] bpf: add bpf_set_reg_range()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] bpf: build failure due to missing step and base fields in struct bpf_reg_state
--

commit b21e96677bd5c8c118c6f3ee527144b5d83b0c82
Author: Eduard Zingerman <eddyz87@gmail.com>

bpf: add bpf_set_reg_range()

A utility function for setting a register's range and step information.
Used by SCEV widening and clamping logic further in the series.

> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 03dbc0e003986..f2d44e026e4bd 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c

[ ... ]

> @@ -16934,6 +16934,18 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
>  	return 0;
>  }
>  
> +int bpf_set_reg_range(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
> +		      struct cnum64 range, u16 step)
> +{
> +	reg->r64 = range;
> +	reg->r32 = CNUM32_UNBOUNDED;
> +	reg->step = step;
> +	reg->base = imod(cnum64_smin(range), step);

[Severity: Low]
Does this code cause a build failure?

It appears that the `step` and `base` fields do not exist in
`struct bpf_reg_state` at this point in the commit history, which would
break `git bisect`.

While this patch splitting error is resolved in the subsequent commit
'[PATCH bpf-next 14/36] bpf: representation for intervals with steps' which
adds the missing fields, each patch in a series must compile independently.

> +	reg->var_off = tnum_unknown;
> +	reg_bounds_sync(reg); /* this should infer the tnum alignment */
> +	return reg_bounds_sanity_check(env, reg, "bpf_set_reg_range");
> +}
> +
>  /* check validity of 32-bit and 64-bit arithmetic operations */

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260926-scev-minimal-rebase-v1-0-c8e5ab5ba79f@gmail.com?part=9