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SubjectRe: [RESEND PATCH] tee: add kernel internal client interface
On Fri, 13 Jul 2018 at 14:54, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> [+Sumit]
>
> On Mon, Jul 09, 2018 at 08:15:49AM +0200, Jens Wiklander wrote:
> > Adds a kernel internal TEE client interface to be used by other drivers.
> >
> > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > ---

Thanks Jens for this patch. I have reviewed and tested this patch on
Developerbox [1]. Following is brief description of my test-case:

Developerbox doesn't have support for hardware based TRNG. But it does
have 7 on-chip thermal sensors accessible from Secure world only. So I
wrote OP-TEE static TA to collect Entropy using thermal noise from
these sensors.
After using the interface provided by this patch, I am able to write
"hw_random" char driver for Developerbox to get Entropy from OP-TEE
static TA which could be further used by user-space daemon (rngd).

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Tested-by: Sumit Garg <sumit.garg@linaro.org>

[1] https://www.96boards.org/product/developerbox/

-Sumit

> > drivers/tee/tee_core.c | 113 +++++++++++++++++++++++++++++++++++++---
> > include/linux/tee_drv.h | 73 ++++++++++++++++++++++++++
> > 2 files changed, 179 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> > index dd46b758852a..7b2bb4c50058 100644
> > --- a/drivers/tee/tee_core.c
> > +++ b/drivers/tee/tee_core.c
> > @@ -38,15 +38,13 @@ static DEFINE_SPINLOCK(driver_lock);
> > static struct class *tee_class;
> > static dev_t tee_devt;
> >
> > -static int tee_open(struct inode *inode, struct file *filp)
> > +static struct tee_context *teedev_open(struct tee_device *teedev)
> > {
> > int rc;
> > - struct tee_device *teedev;
> > struct tee_context *ctx;
> >
> > - teedev = container_of(inode->i_cdev, struct tee_device, cdev);
> > if (!tee_device_get(teedev))
> > - return -EINVAL;
> > + return ERR_PTR(-EINVAL);
> >
> > ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> > if (!ctx) {
> > @@ -57,16 +55,16 @@ static int tee_open(struct inode *inode, struct file *filp)
> > kref_init(&ctx->refcount);
> > ctx->teedev = teedev;
> > INIT_LIST_HEAD(&ctx->list_shm);
> > - filp->private_data = ctx;
> > rc = teedev->desc->ops->open(ctx);
> > if (rc)
> > goto err;
> >
> > - return 0;
> > + return ctx;
> > err:
> > kfree(ctx);
> > tee_device_put(teedev);
> > - return rc;
> > + return ERR_PTR(rc);
> > +
> > }
> >
> > void teedev_ctx_get(struct tee_context *ctx)
> > @@ -100,6 +98,18 @@ static void teedev_close_context(struct tee_context *ctx)
> > teedev_ctx_put(ctx);
> > }
> >
> > +static int tee_open(struct inode *inode, struct file *filp)
> > +{
> > + struct tee_context *ctx;
> > +
> > + ctx = teedev_open(container_of(inode->i_cdev, struct tee_device, cdev));
> > + if (IS_ERR(ctx))
> > + return PTR_ERR(ctx);
> > +
> > + filp->private_data = ctx;
> > + return 0;
> > +}
> > +
> > static int tee_release(struct inode *inode, struct file *filp)
> > {
> > teedev_close_context(filp->private_data);
> > @@ -928,6 +938,95 @@ void *tee_get_drvdata(struct tee_device *teedev)
> > }
> > EXPORT_SYMBOL_GPL(tee_get_drvdata);
> >
> > +struct match_dev_data {
> > + struct tee_ioctl_version_data *vers;
> > + const void *data;
> > + int (*match)(struct tee_ioctl_version_data *, const void *);
> > +};
> > +
> > +static int match_dev(struct device *dev, const void *data)
> > +{
> > + const struct match_dev_data *match_data = data;
> > + struct tee_device *teedev = container_of(dev, struct tee_device, dev);
> > +
> > + teedev->desc->ops->get_version(teedev, match_data->vers);
> > + return match_data->match(match_data->vers, match_data->data);
> > +}
> > +
> > +struct tee_context *
> > +tee_client_open_context(struct tee_context *start,
> > + int (*match)(struct tee_ioctl_version_data *,
> > + const void *),
> > + const void *data, struct tee_ioctl_version_data *vers)
> > +{
> > + struct device *dev = NULL;
> > + struct device *put_dev = NULL;
> > + struct tee_context *ctx = NULL;
> > + struct tee_ioctl_version_data v;
> > + struct match_dev_data match_data = { vers ? vers : &v, data, match };
> > +
> > + if (start)
> > + dev = &start->teedev->dev;
> > +
> > + do {
> > + dev = class_find_device(tee_class, dev, &match_data, match_dev);
> > + if (!dev) {
> > + ctx = ERR_PTR(-ENOENT);
> > + break;
> > + }
> > +
> > + put_device(put_dev);
> > + put_dev = dev;
> > +
> > + ctx = teedev_open(container_of(dev, struct tee_device, dev));
> > + } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
> > +
> > + put_device(put_dev);
> > + return ctx;
> > +}
> > +EXPORT_SYMBOL_GPL(tee_client_open_context);
> > +
> > +void tee_client_close_context(struct tee_context *ctx)
> > +{
> > + teedev_close_context(ctx);
> > +}
> > +EXPORT_SYMBOL_GPL(tee_client_close_context);
> > +
> > +void tee_client_get_version(struct tee_context *ctx,
> > + struct tee_ioctl_version_data *vers)
> > +{
> > + ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
> > +}
> > +EXPORT_SYMBOL_GPL(tee_client_get_version);
> > +
> > +int tee_client_open_session(struct tee_context *ctx,
> > + struct tee_ioctl_open_session_arg *arg,
> > + struct tee_param *param)
> > +{
> > + if (!ctx->teedev->desc->ops->open_session)
> > + return -EINVAL;
> > + return ctx->teedev->desc->ops->open_session(ctx, arg, param);
> > +}
> > +EXPORT_SYMBOL_GPL(tee_client_open_session);
> > +
> > +int tee_client_close_session(struct tee_context *ctx, u32 session)
> > +{
> > + if (!ctx->teedev->desc->ops->close_session)
> > + return -EINVAL;
> > + return ctx->teedev->desc->ops->close_session(ctx, session);
> > +}
> > +EXPORT_SYMBOL_GPL(tee_client_close_session);
> > +
> > +int tee_client_invoke_func(struct tee_context *ctx,
> > + struct tee_ioctl_invoke_arg *arg,
> > + struct tee_param *param)
> > +{
> > + if (!ctx->teedev->desc->ops->invoke_func)
> > + return -EINVAL;
> > + return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
> > +}
> > +EXPORT_SYMBOL_GPL(tee_client_invoke_func);
> > +
> > static int __init tee_init(void)
> > {
> > int rc;
> > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> > index a2b3dfcee0b5..6cfe05893a76 100644
> > --- a/include/linux/tee_drv.h
> > +++ b/include/linux/tee_drv.h
> > @@ -453,6 +453,79 @@ static inline int tee_shm_get_id(struct tee_shm *shm)
> > */
> > struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
> >
> > +/**
> > + * tee_client_open_context() - Open a TEE context
> > + * @start: if not NULL, continue search after this context
> > + * @match: function to check TEE device
> > + * @data: data for match function
> > + * @vers: if not NULL, version data of TEE device of the context returned
> > + *
> > + * This function does an operation similar to open("/dev/teeX") in user space.
> > + * A returned context must be released with tee_client_close_context().
> > + *
> > + * Returns a TEE context of the first TEE device matched by the match()
> > + * callback or an ERR_PTR.
> > + */
> > +struct tee_context *
> > +tee_client_open_context(struct tee_context *start,
> > + int (*match)(struct tee_ioctl_version_data *,
> > + const void *),
> > + const void *data, struct tee_ioctl_version_data *vers);
> > +
> > +/**
> > + * tee_client_close_context() - Close a TEE context
> > + * @ctx: TEE context to close
> > + *
> > + * Note that all sessions previously opened with this context will be
> > + * closed when this function is called.
> > + */
> > +void tee_client_close_context(struct tee_context *ctx);
> > +
> > +/**
> > + * tee_client_get_version() - Query version of TEE
> > + * @ctx: TEE context to TEE to query
> > + * @vers: Pointer to version data
> > + */
> > +void tee_client_get_version(struct tee_context *ctx,
> > + struct tee_ioctl_version_data *vers);
> > +
> > +/**
> > + * tee_client_open_session() - Open a session to a Trusted Application
> > + * @ctx: TEE context
> > + * @arg: Open session arguments, see description of
> > + * struct tee_ioctl_open_session_arg
> > + * @param: Parameters passed to the Trusted Application
> > + *
> > + * Returns < 0 on error else see @arg->ret for result. If @arg->ret
> > + * is TEEC_SUCCESS the session identifier is available in @arg->session.
> > + */
> > +int tee_client_open_session(struct tee_context *ctx,
> > + struct tee_ioctl_open_session_arg *arg,
> > + struct tee_param *param);
> > +
> > +/**
> > + * tee_client_close_session() - Close a session to a Trusted Application
> > + * @ctx: TEE Context
> > + * @session: Session id
> > + *
> > + * Return < 0 on error else 0, regardless the session will not be
> > + * valid after this function has returned.
> > + */
> > +int tee_client_close_session(struct tee_context *ctx, u32 session);
> > +
> > +/**
> > + * tee_client_invoke_func() - Invoke a function in a Trusted Application
> > + * @ctx: TEE Context
> > + * @arg: Invoke arguments, see description of
> > + * struct tee_ioctl_invoke_arg
> > + * @param: Parameters passed to the Trusted Application
> > + *
> > + * Returns < 0 on error else see @arg->ret for result.
> > + */
> > +int tee_client_invoke_func(struct tee_context *ctx,
> > + struct tee_ioctl_invoke_arg *arg,
> > + struct tee_param *param);
> > +
> > static inline bool tee_param_is_memref(struct tee_param *param)
> > {
> > switch (param->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
> > --
> > 2.17.1
> >
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