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

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Date:   Tue, 23 Feb 2021 09:19:48 +0100
From:   Jens Wiklander <jens.wiklander@...aro.org>
To:     Allen Pais <apais@...ux.microsoft.com>
Cc:     Dhananjay Phadke <dphadke@...ux.microsoft.com>,
        allen.lkml@...il.com, zajec5@...il.com,
        linux-kernel@...r.kernel.org, linux-mips@...r.kernel.org,
        op-tee@...ts.trustedfirmware.org,
        linux-arm-kernel@...ts.infradead.org,
        bcm-kernel-feedback-list@...adcom.com
Subject: Re: [PATCH 1/2] optee: fix tee out of memory failure seen during
 kexec reboot

On Mon, Feb 22, 2021 at 06:15:08PM +0530, Allen Pais wrote:
> 
> > On Wed, 17 Feb 2021 14:57:12 +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()?

Cheers,
Jens