Re: [PATCH v3 1/6] io_uring/mock: add basic infra for test mock files

[Jens Axboe <axboe@kernel.dk>]

On 5/30/25 5:45 AM, Pavel Begunkov wrote:
> On 5/30/25 12:31, Jens Axboe wrote:
>> On 5/30/25 2:38 AM, Pavel Begunkov wrote:
>>> io_uring commands provide an ioctl style interface for files to
>>> implement file specific operations. io_uring provides many features and
>>> advanced api to commands, and it's getting hard to test as it requires
>>> specific files/devices.
>>>
>>> Add basic infrastucture for creating special mock files that will be
>>> implementing the cmd api and using various io_uring features we want to
>>> test. It'll also be useful to test some more obscure read/write/polling
>>> edge cases in the future.
>>
>> Do we want to have the creation of a mock file be a privileged
>> operation?
> 
> It doesn't do anything that would warrant that, maybe just yet.
> Do you mean from the security perspective? i.e. making sure a
> user can't exploit it if there is anything to be exploited.
> I'd really hope nobody would compile this thing for non-test
> kernels. Maybe I should make it dependent on lockdep to enforce
> it.

People do all sorts of weird stuff. I know it doesn't do anything
that warrants making it root only, but at least as root only, any
side effects will be limited to that. I think that'd be better than
making it forcibly depend on something unrelated (but debug'y) like
lockdep.

-- 
Jens Axboe