Re: [PATCH v3] tee: optee: Fix supplicant wait loop

[Jens Wiklander]

On Tue, Feb 4, 2025 at 8:45 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Tue, Feb 4, 2025, at 08:34, Sumit Garg wrote:
> > OP-TEE supplicant is a user-space daemon and it's possible for it
> > be hung or crashed or killed in the middle of processing an OP-TEE
> > RPC call. It becomes more complicated when there is incorrect shutdown
> > ordering of the supplicant process vs the OP-TEE client application which
> > can eventually lead to system hang-up waiting for the closure of the
> > client application.
> >
> > Allow the client process waiting in kernel for supplicant response to
> > be killed rather than indefinitely waiting in an unkillable state. Also,
> > a normal uninterruptible wait should not have resulted in the hung-task
> > watchdog getting triggered, but the endless loop would.
> >
> > This fixes issues observed during system reboot/shutdown when supplicant
> > got hung for some reason or gets crashed/killed which lead to client
> > getting hung in an unkillable state. It in turn lead to system being in
> > hung up state requiring hard power off/on to recover.
> >
> > Fixes: 4fb0a5eb364d ("tee: add OP-TEE driver")
> > Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx>
> > Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
>
> Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>

Reviewed-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>

>
> Jens, I assume you'll pick it up and send me a pull request, but
> I can also pick it up directly if you have nothing else.

I have nothing else, please pick up this directly.

Thanks,
Jens