Re: [PATCH 1/2] Input: uinput - Allow uinput_request_submit wait interrupting

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Vicki,

On Wed, Dec 06, 2023 at 10:34:05PM -0800, Vicki Pfau wrote:
> Currently, uinput_request_submit will only fail if the request wait times out.
> However, in other places this wait is interruptable, and in this specific
> location it can lead to issues, such as causing system suspend to hang until
> the request times out.

Could you please explain how a sleeping process can cause suspend to
hang?

> Since the timeout is so long, this can cause the
> appearance of a total system freeze. Making the wait interruptable resolves
> this and possibly further issues.

I think you are trying to find a justification too hard and it does not
make sense, however I agree that allowing to kill the process issuing
the request without waiting for the timeout to expire if the other side
is stuck might be desirable.

I think the best way to use wait_for_completion_killable_timeout()
so that stray signals do not disturb userspace, but the processes can
still be terminated.

Thanks.

-- 
Dmitry