Re: [PATCH v1 00/17] tee: Use bus callbacks instead of driver callbacks

Sumit Garg
2025-12-17T09:02:20Z

On Wed, Dec 17, 2025 at 09:21:41AM +0100, Uwe Kleine-König wrote:
> Hello Sumit,
>
> On Wed, Dec 17, 2025 at 01:25:39PM +0530, Sumit Garg wrote:
> > On Tue, Dec 16, 2025 at 12:08:38PM +0100, Uwe Kleine-König wrote:
> > > On Tue, Dec 16, 2025 at 01:08:38PM +0530, Sumit Garg wrote:
> > > > On Mon, Dec 15, 2025 at 3:02 PM Uwe Kleine-König
> > > > <u.kleine-koenig@baylibre.com> wrote:
> > > > > - Why does optee_probe() in drivers/tee/optee/smc_abi.c unregister all
> > > > > optee devices in its error path (optee_unregister_devices())?
> > > >
> > > > This is mostly to take care of if any device got registered before the
> > > > failure occured. Let me know if you have a better way to address that.
> > >
> > > Without understanding the tee stuff, I'd say: Don't bother and only undo
> > > the things that probe did before the failure.
> >
> > True, but this is special case where if there is any leftover device
> > registered from the TEE implementation then it is likely going to cause
> > the corresponding kernel client driver crash.
>
> You are aware that this is racy? So if a driver crashes e.g. after
> teedev_close_context() it might happen that it is registered just after
> optee_unregister_devices() returns.
>

I see your point about the unavoidable race. Maybe it's better to not
try anything and let the kernel client driver fail.

-Sumit