Re: [PATCH bpf-next v5 4/6] bpftool: generated shadow variables for struct_ops maps.

[Kui-Feng Lee <sinquersw@gmail.com>]

On 2/28/24 13:21, Kui-Feng Lee wrote:
> Will fix most of issues.
> 
> On 2/28/24 10:25, Andrii Nakryiko wrote:
>> On Mon, Feb 26, 2024 at 5:04 PM Kui-Feng Lee <thinker.li@gmail.com> 
>> wrote:
>>>
>>> + * type. Accessing them through the generated names may unintentionally
>>> + * corrupt data.
>>> + */
>>> +static int gen_st_ops_shadow_type(struct btf *btf, const char *ident,
>>> +                                 const struct bpf_map *map)
>>> +{
>>> +       int err;
>>> +
>>> +       printf("\t\tstruct {\n");
>>
>> would it be useful to still name this type? E.g., if it is `struct
>> bpf_struct_ops_tcp_congestion_ops in vmlinux BTF` we can name this one
>> as <skeleton-name>__bpf_struct_ops_tcp_congestion_ops. We have a
>> similar pattern for bss/data/rodata sections, having names is useful.
> 
> If a user defines several struct_ops maps with the same name and type in
> different files, it can cause name conflicts. Unless we also prefix the
> name with the name of the skeleton. I am not sure if it is a good idea
> to generate such long names. If a user want to refer to the type, he
> still can use typeof(). WDYT?

I misread your words. So, you were saying to prefix the skeleton name, 
not map names. It is doable.

> 
>>
>>> +
>>> +       err = walk_st_ops_shadow_vars(btf, ident, map);
>>> +       if (err)
>>> +               return err;
>>> +
>>> +       printf("\t\t} *%s;\n", ident);
>>> +
>>> +       return 0;
>>> +}
>>> +