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Date:   Sat, 18 Dec 2021 18:19:22 -0800
From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
To:     Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc:     bpf@vger.kernel.org, netdev@vger.kernel.org,
        netfilter-devel@vger.kernel.org,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Maxim Mikityanskiy <maximmi@nvidia.com>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
Subject: Re: [PATCH bpf-next v4 04/10] bpf: Introduce mem, size argument pair
 support for kfunc
Message-ID: <20211219021922.2jhnvuhcg4zzcp32@ast-mbp>
References: <20211217015031.1278167-1-memxor@gmail.com>
 <20211217015031.1278167-5-memxor@gmail.com>
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On Fri, Dec 17, 2021 at 07:20:25AM +0530, Kumar Kartikeya Dwivedi wrote:
> +static bool is_kfunc_arg_mem_size(const struct btf *btf,
> +				  const struct btf_param *arg,
> +				  const struct bpf_reg_state *reg)
> +{
> +	const struct btf_type *t;
> +	const char *param_name;
> +
> +	t = btf_type_skip_modifiers(btf, arg->type, NULL);
> +	if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
> +		return false;
> +
> +	/* In the future, this can be ported to use BTF tagging */
> +	param_name = btf_name_by_offset(btf, arg->name_off);
> +	if (strncmp(param_name, "len__", sizeof("len__") - 1))
> +		return false;

I like the feature and approach, but have a suggestion:
The "__sz" suffix would be shorter and more readable.
wdyt?