Re: [PATCH v2 bpf-next 04/18] selftests/bpf: Test helper support for BTF_KIND_LOC[_PARAM|_PROTO|SEC]

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Incorrect format specifiers `%d` used for unsigned `__u32` variables when formatting BTF_KIND_LOC_PARAM and BTF_KIND_LOCSEC.
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commit 775b46a26f73799ae68ad5737114128e343d1d80
Author: Alan Maguire <alan.maguire@oracle.com>

selftests/bpf: Test helper support for BTF_KIND_LOC[_PARAM|_PROTO|SEC]

Add support to dump, encode and validate new location-related kinds.

> diff --git a/tools/testing/selftests/bpf/btf_helpers.c b/tools/testing/selftests/bpf/btf_helpers.c
> index 1c1c2c26690a7..6065ee4ba00a6 100644
> --- a/tools/testing/selftests/bpf/btf_helpers.c
> +++ b/tools/testing/selftests/bpf/btf_helpers.c

[ ... ]

> @@ -203,6 +206,37 @@ int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
>  		fprintf(out, " type_id=%u component_idx=%d",
>  			t->type, btf_decl_tag(t)->component_idx);
>  		break;
> +	case BTF_KIND_LOC_PARAM: {
> +		struct btf_loc_param *p = btf_loc_param(t);
> +		__u32 *v = (__u32 *)(p + 1);
> +
> +		fprintf(out, " size=%d flags=0x%x vlen=%u", t->size, p->flags, vlen);

[Severity: Low]
Does this format string interpret the unsigned __u32 t->size as a signed
integer? If t->size exceeds 2^31-1, it could be printed as a negative number
here, which differs from how other BTF kinds format their sizes using %u.

> +		for (i = 0; i < vlen; i++, v++) {
> +			if (p->flags & BTF_LOC_PARAM_SIGNED)
> +				fprintf(out, "\n\tvalue=%d", (__s32)*v);
> +			else
> +				fprintf(out, "\n\tvalue=%u", *v);
> +		}
> +		break;
> +	}

[ ... ]

> +	case BTF_KIND_LOCSEC: {
> +		const struct btf_loc *l = btf_locsec_locs(t);
> +
> +		fprintf(out, " vlen=%u", vlen);
> +		for (i = 0; i < vlen; i++, l++) {
> +			fprintf(out, "\n\tfunc_type_id=%u loc_proto_type_id=%u offset=%d",
> +				l->func, l->loc_proto, l->offset);

[Severity: Low]
Similarly, l->offset is defined as __u32 in struct btf_loc but is formatted
with %d. Should this use %u as well to prevent large offsets from appearing
negative in the output?

> +		}
> +		break;
> +	}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260901165757.801449-1-alan.maguire@oracle.com?part=4