Re: [PATCH v2 1/2] optee: fix tee out of memory failure seen during kexec reboot

[Jens Wiklander <jens.wiklander@linaro.org>]

On Thu, Feb 25, 2021 at 10:06 AM Allen Pais <allen.lkml@gmail.com> wrote:
>
> From: Allen Pais <apais@linux.microsoft.com>
>
> The following out of memory errors are seen on kexec reboot
> from the optee core.
>
> [    0.368428] tee_bnxt_fw optee-clnt0: tee_shm_alloc failed
> [    0.368461] tee_bnxt_fw: probe of optee-clnt0 failed with error -22
>
> tee_shm_release() is not invoked on dma shm buffer.
>
> Implement .shutdown() method to handle the release of the buffers
> correctly.
>
> More info:
> https://github.com/OP-TEE/optee_os/issues/3637
>
> Signed-off-by: Allen Pais <apais@linux.microsoft.com>
> ---
>  drivers/tee/optee/core.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)

This looks good to me. Do you have a practical way of testing this on
QEMU for instance?

Thanks,
Jens

>
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index cf4718c6d35d..80e2774b5e2a 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -582,6 +582,13 @@ static optee_invoke_fn *get_invoke_func(struct device *dev)
>         return ERR_PTR(-EINVAL);
>  }
>
> +/* optee_remove - Device Removal Routine
> + * @pdev: platform device information struct
> + *
> + * optee_remove is called by platform subsystem to alter the driver
> + * that it should release the device
> + */
> +
>  static int optee_remove(struct platform_device *pdev)
>  {
>         struct optee *optee = platform_get_drvdata(pdev);
> @@ -612,6 +619,18 @@ static int optee_remove(struct platform_device *pdev)
>         return 0;
>  }
>
> +/* optee_shutdown - Device Removal Routine
> + * @pdev: platform device information struct
> + *
> + * platform_shutdown is called by the platform subsystem to alter
> + * the driver that a shutdown/reboot(or kexec) is happening and
> + * device must be disabled.
> + */
> +static void optee_shutdown(struct platform_device *pdev)
> +{
> +       optee_disable_shm_cache(platform_get_drvdata(pdev));
> +}
> +
>  static int optee_probe(struct platform_device *pdev)
>  {
>         optee_invoke_fn *invoke_fn;
> @@ -738,6 +757,7 @@ MODULE_DEVICE_TABLE(of, optee_dt_match);
>  static struct platform_driver optee_driver = {
>         .probe  = optee_probe,
>         .remove = optee_remove,
> +       .shutdown = optee_shutdown,
>         .driver = {
>                 .name = "optee",
>                 .of_match_table = optee_dt_match,
> --
> 2.25.1
>