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References: <20210614223317.999867-1-tyhicks@linux.microsoft.com> <20210614223317.999867-5-tyhicks@linux.microsoft.com>
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From:   Jens Wiklander <jens.wiklander@linaro.org>
Date:   Tue, 15 Jun 2021 09:00:36 +0200
Message-ID: <CAHUa44HeJu9_33H3V=ms5=Z4tKSgQ8=3nWqUDvvNgJvaUB4H=A@mail.gmail.com>
Subject: Re: [PATCH v5 4/8] optee: Clear stale cache entries during initialization
To:     Tyler Hicks <tyhicks@linux.microsoft.com>
Cc:     Allen Pais <apais@linux.microsoft.com>,
        Sumit Garg <sumit.garg@linaro.org>,
        Peter Huewe <peterhuewe@gmx.de>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Vikas Gupta <vikas.gupta@broadcom.com>,
        Thirupathaiah Annapureddy <thiruan@microsoft.com>,
        Pavel Tatashin <pasha.tatashin@soleen.com>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>,
        OP-TEE TrustedFirmware <op-tee@lists.trustedfirmware.org>,
        linux-integrity <linux-integrity@vger.kernel.org>,
        bcm-kernel-feedback-list@broadcom.com, linux-mips@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Tue, Jun 15, 2021 at 12:33 AM Tyler Hicks
<tyhicks@linux.microsoft.com> wrote:
>
> The shm cache could contain invalid addresses if
> optee_disable_shm_cache() was not called from the .shutdown hook of the
> previous kernel before a kexec. These addresses could be unmapped or
> they could point to mapped but unintended locations in memory.
>
> Clear the shared memory cache, while being careful to not translate the
> addresses returned from OPTEE_SMC_DISABLE_SHM_CACHE, during driver
> initialization. Once all pre-cache shm objects are removed, proceed with
> enabling the cache so that we know that we can handle cached shm objects
> with confidence later in the .shutdown hook.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
> ---
>  drivers/tee/optee/call.c          | 36 ++++++++++++++++++++++++++++---
>  drivers/tee/optee/core.c          |  9 ++++++++
>  drivers/tee/optee/optee_private.h |  1 +
>  3 files changed, 43 insertions(+), 3 deletions(-)

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