Re: [PATCH -next v7 1/2] rust: clist: Add support to interface with C linked lists

[Joel Fernandes]

On 2/6/2026 5:33 PM, Daniel Almeida wrote:
>>>
>>>
>>> Yeah, but my point being: is there a reason why the underlying list has to
>>> remain read-only? Is this a safety requirement or an invariant that is established
>>> by the code above?
>> I'm not fully sure if it's an invariant or a safety requirement, but anyone
>> creating a C list head on the rust side must guarantee that it is not modified.
>> Since rust has no visibility on the C side, I believe it is a Rust invariant
>> here that the existence of CListHead assumes that the list cannot be modified
>> once Rust has access over it.  That is up to the creator (user) of the CListHead
>> to guarantee. In the DRM buddy case, once the list is allocated and accessible
>> from Rust, C code will not modify it while the Rust object exists.
>>
>> Does that make sense, or is there a better way to document this?
>>
>> --
>> Joel Fernandes
> 
> 
> In which case, I recommend moving this to a safety requirement when
> creating the list.

Ok, will do.
> I assume the purpose of not modifying the list on the C side is to avoid
> corrupting the list in Rust somehow?

Yes.

Thanks,

-- 
Joel Fernandes