Re: [PATCH bpf-next 28/36] selftests/bpf: test for stack-pointer subrange pruning

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] bpf: incorrect multi-line comment style
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commit 928bc76d46def360ecb11c2c10278100fdf80716
Author: Eduard Zingerman <eddyz87@gmail.com>
Subject: selftests/bpf: test for stack-pointer subrange pruning

This commit adds a test case to validate widened stack pointer subrange
relations in regsafe(). It checks that a widened stack pointer with range
[-64, -8] is treated as a superset of [-56, -8].

> diff --git a/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
> index 3e0bea9819cab..5da8b9a6018cf 100644
> --- a/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
> +++ b/tools/testing/selftests/bpf/progs/verifier_stack_ptr.c
> @@ -586,4 +586,37 @@ __naked void stack_check_size_512_with_may_goto(void)
>  }
>  #endif
>  
> +/* Verify that old PTR_TO_STACK state is considered a super-set of
> + * new PTR_TO_STACK state when new variable range is a sub-range
> + * of the old range, e.g. old [-72, -16] vs new [-64, -16].
> + */

[Severity: Low]
Does this violate the BPF subsystem multi-line comment style? The BPF 
subsystem requires multi-line comments to have the opening /* on its 
own line, with the text starting on the next line.

> +SEC("socket")
> +__success
> +__log_level(2)
> +__flag(BPF_F_TEST_STATE_FREQ)
> +/* r7 is widened to [-72, -16] at the loop header (insn 3),
> + * the loop body sees [-64, -8] after 'r7 += 8'
> + */

[Severity: Low]
Should this comment also be updated to start the text on the line following
the opening /* to match the subsystem standards?

> +__msg("loop header at 3, widening r7 to -72..-16 step 8")
> +__msg("R7=fp(smin=smin32=-64,smax=smax32=-8")
> +/* back-edge state is clamped to the remaining iterations and pruned
> + * at the header, because [-64, -16] is within the widened [-72, -16]
> + */

[Severity: Low]
Would it be better to adjust this comment block as well to ensure the opening
/* is placed on a separate line?

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260926-scev-minimal-rebase-v1-0-c8e5ab5ba79f@gmail.com?part=28