diff mbox series

[v1,02/14] tee: add register user memory

Message ID 1506621851-6929-3-git-send-email-volodymyr_babchuk@epam.com
State Superseded
Headers show
Series [v1,01/14] tee: flexible shared memory pool creation | expand

Commit Message

Volodymyr Babchuk Sept. 28, 2017, 6:03 p.m. UTC
From: Jens Wiklander <jens.wiklander@linaro.org>


Added new ioctl to allow users register own buffers as a shared memory.

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

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>

---
 drivers/tee/tee_core.c   |  41 ++++++++-
 drivers/tee/tee_shm.c    | 210 +++++++++++++++++++++++++++++++++++++++++------
 include/linux/tee_drv.h  |  44 +++++++++-
 include/uapi/linux/tee.h |  30 +++++++
 4 files changed, 295 insertions(+), 30 deletions(-)

-- 
2.7.4

Comments

Mark Rutland Sept. 29, 2017, 10:53 a.m. UTC | #1
On Thu, Sep 28, 2017 at 09:03:59PM +0300, Volodymyr Babchuk wrote:
> +static int

> +tee_ioctl_shm_register(struct tee_context *ctx,

> +		       struct tee_ioctl_shm_register_data __user *udata)

> +{

> +	long ret;

> +	struct tee_ioctl_shm_register_data data;

> +	struct tee_shm *shm;

> +

> +	if (copy_from_user(&data, udata, sizeof(data)))

> +		return -EFAULT;

> +

> +	/* Currently no input flags are supported */

> +	if (data.flags)

> +		return -EINVAL;

> +

> +	shm = tee_shm_register(ctx, data.addr, data.length,

> +			       TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);

> +	if (IS_ERR(shm))

> +		return PTR_ERR(shm);

> +

> +	data.id = shm->id;

> +	data.flags = shm->flags;

> +	data.length = shm->size;

> +

> +	if (copy_to_user(udata, &data, sizeof(data)))

> +		ret = -EFAULT;

> +	else

> +		ret = tee_shm_get_fd(shm);


Why do you need both the fd and an id? That seems redundant.

[...]

> +struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,

> +				 size_t length, u32 flags)

> +{

> +	struct tee_device *teedev = ctx->teedev;

> +	const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;

> +	struct tee_shm *shm;

> +	void *ret;

> +	int rc;

> +	int num_pages;

> +	unsigned long start;

> +

> +	if (flags != req_flags) {

> +		dev_err(teedev->dev.parent, "invliad shm flags %#x", flags);

> +		return ERR_PTR(-EINVAL);

> +	}

> +

> +	if (!tee_device_get(teedev))

> +		return ERR_PTR(-EINVAL);

> +

> +	if (!teedev->desc->ops->shm_register ||

> +	    !teedev->desc->ops->shm_unregister) {

> +		dev_err(teedev->dev.parent,

> +			"register shared memory unspported by device");


I don't think this should be a dev_err. The user requested something
that the device did not support, but that's not a device-side error.

A user may legitmiately do this to probe whether the TEE supports
registering memory.

> +		tee_device_put(teedev);

> +		return ERR_PTR(-EINVAL);


Perhaps EOPNOTSUPP?

> +	}

> +

> +	shm = kzalloc(sizeof(*shm), GFP_KERNEL);

> +	if (!shm) {

> +		ret = ERR_PTR(-ENOMEM);

> +		goto err;

> +	}

> +

> +	shm->flags = flags | TEE_SHM_REGISTER;

> +	shm->teedev = teedev;

> +	shm->ctx = ctx;

> +	shm->id = -1;

> +	start = rounddown(addr, PAGE_SIZE);

> +	shm->offset = addr - start;

> +	shm->size = length;

> +	num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;


Why not mandate that the user passes a buffer which has a start and end
aligned to PAGE_SIZE?

Otherwise, the buffer is size is silently upgraded without the user's
knowledge, which seems likely to result in bugs.

> +	shm->pages = kcalloc(num_pages, sizeof(struct page), GFP_KERNEL);


I think you mean sizeof(struct page *) here.

Generally, for:

  lhs = some_alloc(sizeof(x))

... it's preferred that x is *lhs, so as to keep the types in sync. e.g.

  shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);

> +	if (!shm->pages) {

> +		ret = ERR_PTR(-ENOMEM);

> +		goto err;

> +	}

> +

> +	rc = get_user_pages_fast(start, num_pages, 1, shm->pages);

> +	if (rc > 0)

> +		shm->num_pages = rc;

> +	if (rc != num_pages) {

> +		if (rc > 0)

> +			rc = -ENOMEM;

> +		ret = ERR_PTR(rc);

> +		goto err;

> +	}

> +

> +	mutex_lock(&teedev->mutex);

> +	shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);

> +	mutex_unlock(&teedev->mutex);


AFAICT, idr_alloc() can fail, so I beleive you're missing a sanity check
on the return value here.

THanks,
Mark.
Volodymyr Babchuk Sept. 29, 2017, 3:19 p.m. UTC | #2
On 29.09.17 13:53, Mark Rutland wrote:
> On Thu, Sep 28, 2017 at 09:03:59PM +0300, Volodymyr Babchuk wrote:

>> +static int

>> +tee_ioctl_shm_register(struct tee_context *ctx,

>> +		       struct tee_ioctl_shm_register_data __user *udata)

>> +{

>> +	long ret;

>> +	struct tee_ioctl_shm_register_data data;

>> +	struct tee_shm *shm;

>> +

>> +	if (copy_from_user(&data, udata, sizeof(data)))

>> +		return -EFAULT;

>> +

>> +	/* Currently no input flags are supported */

>> +	if (data.flags)

>> +		return -EINVAL;

>> +

>> +	shm = tee_shm_register(ctx, data.addr, data.length,

>> +			       TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);

>> +	if (IS_ERR(shm))

>> +		return PTR_ERR(shm);

>> +

>> +	data.id = shm->id;

>> +	data.flags = shm->flags;

>> +	data.length = shm->size;

>> +

>> +	if (copy_to_user(udata, &data, sizeof(data)))

>> +		ret = -EFAULT;

>> +	else

>> +		ret = tee_shm_get_fd(shm);

> 

> Why do you need both the fd and an id? That seems redundant.

> 

> [...]

Not exactly. This approach is used for all shared memory object types.
fd is used to control life cycle. id identifies the buffer.
There are at least three types of shared memory objects available:

  - Allocated memory is already present in tee subsystem
  - My patch series add registered shared memory
  - There are patches in linaro branch that add support for
    dma_buf shared memory objects

It it easier to identify them all with id, that with fd (which can be 
tricky in case of dma_buf objects, by the way).

>> +struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,

>> +				 size_t length, u32 flags)

>> +{

>> +	struct tee_device *teedev = ctx->teedev;

>> +	const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;

>> +	struct tee_shm *shm;

>> +	void *ret;

>> +	int rc;

>> +	int num_pages;

>> +	unsigned long start;

>> +

>> +	if (flags != req_flags) {

>> +		dev_err(teedev->dev.parent, "invliad shm flags %#x", flags);

>> +		return ERR_PTR(-EINVAL);

>> +	}

>> +

>> +	if (!tee_device_get(teedev))

>> +		return ERR_PTR(-EINVAL);

>> +

>> +	if (!teedev->desc->ops->shm_register ||

>> +	    !teedev->desc->ops->shm_unregister) {

>> +		dev_err(teedev->dev.parent,

>> +			"register shared memory unspported by device");

> 

> I don't think this should be a dev_err. The user requested something

> that the device did not support, but that's not a device-side error.

> 

> A user may legitmiately do this to probe whether the TEE supports

> registering memory.

Agree. I'll remove dev_err() invocation.

>> +		tee_device_put(teedev);

>> +		return ERR_PTR(-EINVAL);

> 

> Perhaps EOPNOTSUPP?

Sure. Thanks.

>> +	}

>> +

>> +	shm = kzalloc(sizeof(*shm), GFP_KERNEL);

>> +	if (!shm) {

>> +		ret = ERR_PTR(-ENOMEM);

>> +		goto err;

>> +	}

>> +

>> +	shm->flags = flags | TEE_SHM_REGISTER;

>> +	shm->teedev = teedev;

>> +	shm->ctx = ctx;

>> +	shm->id = -1;

>> +	start = rounddown(addr, PAGE_SIZE);

>> +	shm->offset = addr - start;

>> +	shm->size = length;

>> +	num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;

> 

> Why not mandate that the user passes a buffer which has a start and end

> aligned to PAGE_SIZE?

> 

> Otherwise, the buffer is size is silently upgraded without the user's

> knowledge, which seems likely to result in bugs.

Because according to GlobalPlatform TEE specification, client can 
register any portion of own memory. I agree that it is error-prone to 
allow TEE (and TA) to see not shared parts of client memory. But in 
terms of GlobalPlatform, Linux and its userspace considered as 
non-secure anyways. While TEE and TAs are considered trusted.
Misbehaved TEE or TA anyways can do many bad things, so corruption of 
userspace memory does not look so bad.

>> +	shm->pages = kcalloc(num_pages, sizeof(struct page), GFP_KERNEL);

> 

> I think you mean sizeof(struct page *) here.

Ooops. Good catch. Thank you

> Generally, for:

> 

>    lhs = some_alloc(sizeof(x))

> 

> ... it's preferred that x is *lhs, so as to keep the types in sync. e.g.

> 

>    shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);

Yes, will do in this way. Thank you.


>> +	if (!shm->pages) {

>> +		ret = ERR_PTR(-ENOMEM);

>> +		goto err;

>> +	}

>> +

>> +	rc = get_user_pages_fast(start, num_pages, 1, shm->pages);

>> +	if (rc > 0)

>> +		shm->num_pages = rc;

>> +	if (rc != num_pages) {

>> +		if (rc > 0)

>> +			rc = -ENOMEM;

>> +		ret = ERR_PTR(rc);

>> +		goto err;

>> +	}

>> +

>> +	mutex_lock(&teedev->mutex);

>> +	shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);

>> +	mutex_unlock(&teedev->mutex);

> 

> AFAICT, idr_alloc() can fail, so I beleive you're missing a sanity check

> on the return value here.

You are right. Will fix.

Thank you for the review.
diff mbox series

Patch

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 58a5009..295910f 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -114,8 +114,6 @@  static int tee_ioctl_shm_alloc(struct tee_context *ctx,
 	if (data.flags)
 		return -EINVAL;
 
-	data.id = -1;
-
 	shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
 	if (IS_ERR(shm))
 		return PTR_ERR(shm);
@@ -138,6 +136,43 @@  static int tee_ioctl_shm_alloc(struct tee_context *ctx,
 	return ret;
 }
 
+static int
+tee_ioctl_shm_register(struct tee_context *ctx,
+		       struct tee_ioctl_shm_register_data __user *udata)
+{
+	long ret;
+	struct tee_ioctl_shm_register_data data;
+	struct tee_shm *shm;
+
+	if (copy_from_user(&data, udata, sizeof(data)))
+		return -EFAULT;
+
+	/* Currently no input flags are supported */
+	if (data.flags)
+		return -EINVAL;
+
+	shm = tee_shm_register(ctx, data.addr, data.length,
+			       TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
+	if (IS_ERR(shm))
+		return PTR_ERR(shm);
+
+	data.id = shm->id;
+	data.flags = shm->flags;
+	data.length = shm->size;
+
+	if (copy_to_user(udata, &data, sizeof(data)))
+		ret = -EFAULT;
+	else
+		ret = tee_shm_get_fd(shm);
+	/*
+	 * When user space closes the file descriptor the shared memory
+	 * should be freed or if tee_shm_get_fd() failed then it will
+	 * be freed immediately.
+	 */
+	tee_shm_put(shm);
+	return ret;
+}
+
 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
 			    size_t num_params,
 			    struct tee_ioctl_param __user *uparams)
@@ -586,6 +621,8 @@  static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return tee_ioctl_version(ctx, uarg);
 	case TEE_IOC_SHM_ALLOC:
 		return tee_ioctl_shm_alloc(ctx, uarg);
+	case TEE_IOC_SHM_REGISTER:
+		return tee_ioctl_shm_register(ctx, uarg);
 	case TEE_IOC_OPEN_SESSION:
 		return tee_ioctl_open_session(ctx, uarg);
 	case TEE_IOC_INVOKE:
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index fdda89e..1ed708c 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -23,7 +23,6 @@ 
 static void tee_shm_release(struct tee_shm *shm)
 {
 	struct tee_device *teedev = shm->teedev;
-	struct tee_shm_pool_mgr *poolm;
 
 	mutex_lock(&teedev->mutex);
 	idr_remove(&teedev->idr, shm->id);
@@ -31,12 +30,29 @@  static void tee_shm_release(struct tee_shm *shm)
 		list_del(&shm->link);
 	mutex_unlock(&teedev->mutex);
 
-	if (shm->flags & TEE_SHM_DMA_BUF)
-		poolm = teedev->pool->dma_buf_mgr;
-	else
-		poolm = teedev->pool->private_mgr;
+	if (shm->flags & TEE_SHM_POOL) {
+		struct tee_shm_pool_mgr *poolm;
+
+		if (shm->flags & TEE_SHM_DMA_BUF)
+			poolm = teedev->pool->dma_buf_mgr;
+		else
+			poolm = teedev->pool->private_mgr;
+
+		poolm->ops->free(poolm, shm);
+	} else if (shm->flags & TEE_SHM_REGISTER) {
+		size_t n;
+		int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
+
+		if (rc)
+			dev_err(teedev->dev.parent,
+				"unregister shm %p failed: %d", shm, rc);
+
+		for (n = 0; n < shm->num_pages; n++)
+			put_page(shm->pages[n]);
+
+		kfree(shm->pages);
+	}
 
-	poolm->ops->free(poolm, shm);
 	kfree(shm);
 
 	tee_device_put(teedev);
@@ -76,6 +92,10 @@  static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
 	struct tee_shm *shm = dmabuf->priv;
 	size_t size = vma->vm_end - vma->vm_start;
 
+	/* Refuse sharing shared memory provided by application */
+	if (shm->flags & TEE_SHM_REGISTER)
+		return -EINVAL;
+
 	return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
 			       size, vma->vm_page_prot);
 }
@@ -89,26 +109,20 @@  static const struct dma_buf_ops tee_shm_dma_buf_ops = {
 	.mmap = tee_shm_op_mmap,
 };
 
-/**
- * tee_shm_alloc() - Allocate shared memory
- * @ctx:	Context that allocates the shared memory
- * @size:	Requested size of shared memory
- * @flags:	Flags setting properties for the requested shared memory.
- *
- * Memory allocated as global shared memory is automatically freed when the
- * TEE file pointer is closed. The @flags field uses the bits defined by
- * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
- * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
- * associated with a dma-buf handle, else driver private memory.
- */
-struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
+struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
+				struct tee_device *teedev,
+				size_t size, u32 flags)
 {
-	struct tee_device *teedev = ctx->teedev;
 	struct tee_shm_pool_mgr *poolm = NULL;
 	struct tee_shm *shm;
 	void *ret;
 	int rc;
 
+	if (ctx && ctx->teedev != teedev) {
+		dev_err(teedev->dev.parent, "ctx and teedev mismatch\n");
+		return ERR_PTR(-EINVAL);
+	}
+
 	if (!(flags & TEE_SHM_MAPPED)) {
 		dev_err(teedev->dev.parent,
 			"only mapped allocations supported\n");
@@ -135,7 +149,7 @@  struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
 		goto err_dev_put;
 	}
 
-	shm->flags = flags;
+	shm->flags = flags | TEE_SHM_POOL;
 	shm->teedev = teedev;
 	shm->ctx = ctx;
 	if (flags & TEE_SHM_DMA_BUF)
@@ -171,9 +185,12 @@  struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
 			goto err_rem;
 		}
 	}
-	mutex_lock(&teedev->mutex);
-	list_add_tail(&shm->link, &ctx->list_shm);
-	mutex_unlock(&teedev->mutex);
+
+	if (ctx) {
+		mutex_lock(&teedev->mutex);
+		list_add_tail(&shm->link, &ctx->list_shm);
+		mutex_unlock(&teedev->mutex);
+	}
 
 	return shm;
 err_rem:
@@ -188,8 +205,138 @@  struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
 	tee_device_put(teedev);
 	return ret;
 }
+/**
+ * tee_shm_alloc() - Allocate shared memory
+ * @ctx:	Context that allocates the shared memory
+ * @size:	Requested size of shared memory
+ * @flags:	Flags setting properties for the requested shared memory.
+ *
+ * Memory allocated as global shared memory is automatically freed when the
+ * TEE file pointer is closed. The @flags field uses the bits defined by
+ * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
+ * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
+ * associated with a dma-buf handle, else driver private memory.
+ */
+struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
+{
+	return __tee_shm_alloc(ctx, ctx->teedev, size, flags);
+}
 EXPORT_SYMBOL_GPL(tee_shm_alloc);
 
+struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size)
+{
+	return __tee_shm_alloc(NULL, teedev, size, TEE_SHM_MAPPED);
+}
+EXPORT_SYMBOL_GPL(tee_shm_priv_alloc);
+
+struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
+				 size_t length, u32 flags)
+{
+	struct tee_device *teedev = ctx->teedev;
+	const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
+	struct tee_shm *shm;
+	void *ret;
+	int rc;
+	int num_pages;
+	unsigned long start;
+
+	if (flags != req_flags) {
+		dev_err(teedev->dev.parent, "invliad shm flags %#x", flags);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!tee_device_get(teedev))
+		return ERR_PTR(-EINVAL);
+
+	if (!teedev->desc->ops->shm_register ||
+	    !teedev->desc->ops->shm_unregister) {
+		dev_err(teedev->dev.parent,
+			"register shared memory unspported by device");
+		tee_device_put(teedev);
+		return ERR_PTR(-EINVAL);
+	}
+
+	shm = kzalloc(sizeof(*shm), GFP_KERNEL);
+	if (!shm) {
+		ret = ERR_PTR(-ENOMEM);
+		goto err;
+	}
+
+	shm->flags = flags | TEE_SHM_REGISTER;
+	shm->teedev = teedev;
+	shm->ctx = ctx;
+	shm->id = -1;
+	start = rounddown(addr, PAGE_SIZE);
+	shm->offset = addr - start;
+	shm->size = length;
+	num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
+	shm->pages = kcalloc(num_pages, sizeof(struct page), GFP_KERNEL);
+	if (!shm->pages) {
+		ret = ERR_PTR(-ENOMEM);
+		goto err;
+	}
+
+	rc = get_user_pages_fast(start, num_pages, 1, shm->pages);
+	if (rc > 0)
+		shm->num_pages = rc;
+	if (rc != num_pages) {
+		if (rc > 0)
+			rc = -ENOMEM;
+		ret = ERR_PTR(rc);
+		goto err;
+	}
+
+	mutex_lock(&teedev->mutex);
+	shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
+	mutex_unlock(&teedev->mutex);
+
+	rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
+					     shm->num_pages);
+	if (rc) {
+		ret = ERR_PTR(rc);
+		goto err;
+	}
+
+	if (flags & TEE_SHM_DMA_BUF) {
+		DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+		exp_info.ops = &tee_shm_dma_buf_ops;
+		exp_info.size = shm->size;
+		exp_info.flags = O_RDWR;
+		exp_info.priv = shm;
+
+		shm->dmabuf = dma_buf_export(&exp_info);
+		if (IS_ERR(shm->dmabuf)) {
+			ret = ERR_CAST(shm->dmabuf);
+			teedev->desc->ops->shm_unregister(ctx, shm);
+			goto err;
+		}
+	}
+
+	mutex_lock(&teedev->mutex);
+	list_add_tail(&shm->link, &ctx->list_shm);
+	mutex_unlock(&teedev->mutex);
+
+	return shm;
+err:
+	if (shm) {
+		size_t n;
+
+		if (shm->id >= 0) {
+			mutex_lock(&teedev->mutex);
+			idr_remove(&teedev->idr, shm->id);
+			mutex_unlock(&teedev->mutex);
+		}
+		for (n = 0; n < shm->num_pages; n++)
+			put_page(shm->pages[n]);
+		kfree(shm->pages);
+	}
+	kfree(shm);
+	tee_device_put(teedev);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tee_shm_register);
+
 /**
  * tee_shm_get_fd() - Increase reference count and return file descriptor
  * @shm:	Shared memory handle
@@ -197,10 +344,9 @@  EXPORT_SYMBOL_GPL(tee_shm_alloc);
  */
 int tee_shm_get_fd(struct tee_shm *shm)
 {
-	u32 req_flags = TEE_SHM_MAPPED | TEE_SHM_DMA_BUF;
 	int fd;
 
-	if ((shm->flags & req_flags) != req_flags)
+	if (!(shm->flags & TEE_SHM_DMA_BUF))
 		return -EINVAL;
 
 	fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
@@ -238,6 +384,8 @@  EXPORT_SYMBOL_GPL(tee_shm_free);
  */
 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
 {
+	if (!(shm->flags & TEE_SHM_MAPPED))
+		return -EINVAL;
 	/* Check that we're in the range of the shm */
 	if ((char *)va < (char *)shm->kaddr)
 		return -EINVAL;
@@ -258,6 +406,8 @@  EXPORT_SYMBOL_GPL(tee_shm_va2pa);
  */
 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
 {
+	if (!(shm->flags & TEE_SHM_MAPPED))
+		return -EINVAL;
 	/* Check that we're in the range of the shm */
 	if (pa < shm->paddr)
 		return -EINVAL;
@@ -284,6 +434,8 @@  EXPORT_SYMBOL_GPL(tee_shm_pa2va);
  */
 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
 {
+	if (!(shm->flags & TEE_SHM_MAPPED))
+		return ERR_PTR(-EINVAL);
 	if (offs >= shm->size)
 		return ERR_PTR(-EINVAL);
 	return (char *)shm->kaddr + offs;
@@ -335,6 +487,12 @@  struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
 
+bool tee_shm_is_registered(struct tee_shm *shm)
+{
+	return shm && (shm->flags & TEE_SHM_REGISTER);
+}
+EXPORT_SYMBOL_GPL(tee_shm_is_registered);
+
 /**
  * tee_shm_get_id() - Get id of a shared memory object
  * @shm:	Shared memory handle
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index e9be4a4..49d6361 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -25,8 +25,12 @@ 
  * specific TEE driver.
  */
 
-#define TEE_SHM_MAPPED		0x1	/* Memory mapped by the kernel */
-#define TEE_SHM_DMA_BUF		0x2	/* Memory with dma-buf handle */
+#define TEE_SHM_MAPPED		BIT(0)	/* Memory mapped by the kernel */
+#define TEE_SHM_DMA_BUF		BIT(1)	/* Memory with dma-buf handle */
+#define TEE_SHM_EXT_DMA_BUF	BIT(2)	/* Memory with dma-buf handle */
+#define TEE_SHM_REGISTER	BIT(3)  /* Memory registered in secure world */
+#define TEE_SHM_USER_MAPPED	BIT(4)  /* Memory mapped in user space */
+#define TEE_SHM_POOL		BIT(5)  /* Memory allocated from pool */
 
 struct device;
 struct tee_device;
@@ -76,6 +80,8 @@  struct tee_param {
  * @cancel_req:		request cancel of an ongoing invoke or open
  * @supp_revc:		called for supplicant to get a command
  * @supp_send:		called for supplicant to send a response
+ * @shm_register:	register shared memory buffer in TEE
+ * @shm_unregister:	unregister shared memory buffer in TEE
  */
 struct tee_driver_ops {
 	void (*get_version)(struct tee_device *teedev,
@@ -94,6 +100,9 @@  struct tee_driver_ops {
 			 struct tee_param *param);
 	int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
 			 struct tee_param *param);
+	int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,
+			    struct page **pages, size_t num_pages);
+	int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm);
 };
 
 /**
@@ -302,6 +311,30 @@  void *tee_get_drvdata(struct tee_device *teedev);
 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags);
 
 /**
+ * tee_shm_priv_alloc() - Allocate shared memory privately
+ * @dev:	Device that allocates the shared memory
+ * @size:	Requested size of shared memory
+ *
+ * Allocates shared memory buffer that is not associated with any client
+ * context. Such buffers are owned by TEE driver and used for internal calls.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size);
+
+/**
+ * tee_shm_register() - Register shared memory buffer
+ * @ctx:	Context that registers the shared memory
+ * @addr:	Address is userspace of the shared buffer
+ * @length:	Length of the shared buffer
+ * @flags:	Flags setting properties for the requested shared memory.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
+				 size_t length, u32 flags);
+
+/**
  * tee_shm_free() - Free shared memory
  * @shm:	Handle to shared memory to free
  */
@@ -366,4 +399,11 @@  int tee_shm_get_id(struct tee_shm *shm);
  */
 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
 
+/**
+ * tee_shm_is_registered() - Check if shared memory object in registered in TEE
+ * @shm:	Shared memory handle
+ * @returns true if object is registered in TEE
+ */
+bool tee_shm_is_registered(struct tee_shm *shm);
+
 #endif /*__TEE_DRV_H*/
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 688782e..d41a07a 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -50,6 +50,7 @@ 
 
 #define TEE_GEN_CAP_GP		(1 << 0)/* GlobalPlatform compliant TEE */
 #define TEE_GEN_CAP_PRIVILEGED	(1 << 1)/* Privileged device (for supplicant) */
+#define TEE_GEN_CAP_REG_MEM	(1 << 2)/* Supports registering shared memory */
 
 /*
  * TEE Implementation ID
@@ -332,6 +333,35 @@  struct tee_iocl_supp_send_arg {
 #define TEE_IOC_SUPPL_SEND	_IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 7, \
 				     struct tee_ioctl_buf_data)
 
+/**
+ * struct tee_ioctl_shm_register_data - Shared memory register argument
+ * @addr:      [in] Start address of shared memory to register
+ * @length:    [in/out] Length of shared memory to register
+ * @flags:     [in/out] Flags to/from registration.
+ * @id:                [out] Identifier of the shared memory
+ *
+ * The flags field should currently be zero as input. Updated by the call
+ * with actual flags as defined by TEE_IOCTL_SHM_* above.
+ * This structure is used as argument for TEE_IOC_SHM_REGISTER below.
+ */
+struct tee_ioctl_shm_register_data {
+	__u64 addr;
+	__u64 length;
+	__u32 flags;
+	__s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_REGISTER - Register shared memory argument
+ *
+ * Registers shared memory between the user space process and secure OS.
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The shared memory is unregisterred when the descriptor is closed.
+ */
+#define TEE_IOC_SHM_REGISTER   _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 9, \
+				     struct tee_ioctl_shm_register_data)
 /*
  * Five syscalls are used when communicating with the TEE driver.
  * open(): opens the device associated with the driver