Re: [PATCH 1/2] optee: fix tee out of memory failure seen during kexec reboot

From: Jens Wiklander
Date: Wed Feb 24 2021 - 03:17:32 EST


On Tue, Feb 23, 2021 at 09:56:13PM +0530, Allen Pais wrote:
>
>
> > > > > - /*
> > > > > - * Ask OP-TEE to free all cached shared memory objects to decrease
> > > > > - * reference counters and also avoid wild pointers in secure world
> > > > > - * into the old shared memory range.
> > > > > - */
> > > > > - optee_disable_shm_cache(optee);
> > > > > + if (shutdown) {
> > > > > + optee_disable_shm_cache(optee);
> > > > > + } else {
> > > > > + /*
> > > > > + * Ask OP-TEE to free all cached shared memory
> > > > > + * objects to decrease reference counters and
> > > > > + * also avoid wild pointers in secure world
> > > > > + * into the old shared memory range.
> > > > > + */
> > > > > + optee_disable_shm_cache(optee);
> > > > Calling optee_disable_shm_cache() in both if and else. It could be
> > > > put in front of if().
> > > >
> > >
> > > Ideally, I could just use optee_remove for shutdown() too.
> > > But it would not look good. Hence this approach.
> >
> > What is the problem with using optee_remove() for shutdown()?
> >
>
> There is no problem, I just thought it would be more cleaner/readable
> with this approach. If you'd like to keep it simple by just calling
> optee_remove() for shutdown() too, I could quickly send out V2.

In the patch you posted it looks like you'd like to call
only optee_disable_shm_cache() in the case of shutdown. Like:

static void optee_shutdown(struct platform_device *pdev)
{
optee_disable_shm_cache(platform_get_drvdata(pdev));
}

and optee_remove() kept as it was before this patch.

Cheers,
Jens