From: Etienne Carriere <etienne.carriere@linaro.org>
Enable userspace to create a tee_shm object that refers to a dmabuf
reference.
Userspace registers the dmabuf file descriptor as in a tee_shm object.
The registration is completed with a tee_shm file descriptor returned to
userspace.
Userspace is free to close the dmabuf file descriptor now since all the
resources are now held via the tee_shm object.
Closing the tee_shm file descriptor will release all resources used by the
tee_shm object.
This change only support dmabuf references that relates to physically
contiguous memory buffers.
New tee_shm flag to identify tee_shm objects built from a registered
dmabuf, TEE_SHM_DMA_BUF.
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Olivier Masse <olivier.masse@nxp.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
drivers/tee/tee_core.c | 145 ++++++++++++++++++++++++++-----------
drivers/tee/tee_private.h | 1 +
drivers/tee/tee_shm.c | 146 ++++++++++++++++++++++++++++++++++++--
include/linux/tee_core.h | 1 +
include/linux/tee_drv.h | 10 +++
include/uapi/linux/tee.h | 29 ++++++++
6 files changed, 288 insertions(+), 44 deletions(-)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 685afcaa3ea1..3a71643766d5 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -353,6 +353,103 @@ tee_ioctl_shm_register(struct tee_context *ctx,
return ret;
}
+static int
+tee_ioctl_shm_register_fd(struct tee_context *ctx,
+ struct tee_ioctl_shm_register_fd_data __user *udata)
+{
+ struct tee_ioctl_shm_register_fd_data data;
+ struct tee_shm *shm;
+ long ret;
+
+ 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_fd(ctx, data.fd);
+ if (IS_ERR(shm))
+ return -EINVAL;
+
+ data.id = shm->id;
+ data.flags = shm->flags;
+ data.size = 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 param_from_user_memref(struct tee_context *ctx,
+ struct tee_param_memref *memref,
+ struct tee_ioctl_param *ip)
+{
+ struct tee_shm *shm;
+ size_t offs = 0;
+
+ /*
+ * If a NULL pointer is passed to a TA in the TEE,
+ * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
+ * indicating a NULL memory reference.
+ */
+ if (ip->c != TEE_MEMREF_NULL) {
+ /*
+ * If we fail to get a pointer to a shared
+ * memory object (and increase the ref count)
+ * from an identifier we return an error. All
+ * pointers that has been added in params have
+ * an increased ref count. It's the callers
+ * responibility to do tee_shm_put() on all
+ * resolved pointers.
+ */
+ shm = tee_shm_get_from_id(ctx, ip->c);
+ if (IS_ERR(shm))
+ return PTR_ERR(shm);
+
+ /*
+ * Ensure offset + size does not overflow
+ * offset and does not overflow the size of
+ * the referred shared memory object.
+ */
+ if ((ip->a + ip->b) < ip->a ||
+ (ip->a + ip->b) > shm->size) {
+ tee_shm_put(shm);
+ return -EINVAL;
+ }
+
+ if (shm->flags & TEE_SHM_DMA_BUF) {
+ struct tee_shm *parent_shm;
+
+ parent_shm = tee_shm_get_parent_shm(shm, &offs);
+ if (parent_shm) {
+ tee_shm_put(shm);
+ shm = parent_shm;
+ }
+ }
+ } else if (ctx->cap_memref_null) {
+ /* Pass NULL pointer to OP-TEE */
+ shm = NULL;
+ } else {
+ return -EINVAL;
+ }
+
+ memref->shm_offs = ip->a + offs;
+ memref->size = ip->b;
+ memref->shm = shm;
+
+ return 0;
+}
+
static int params_from_user(struct tee_context *ctx, struct tee_param *params,
size_t num_params,
struct tee_ioctl_param __user *uparams)
@@ -360,8 +457,8 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
size_t n;
for (n = 0; n < num_params; n++) {
- struct tee_shm *shm;
struct tee_ioctl_param ip;
+ int rc;
if (copy_from_user(&ip, uparams + n, sizeof(ip)))
return -EFAULT;
@@ -384,45 +481,10 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
- /*
- * If a NULL pointer is passed to a TA in the TEE,
- * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
- * indicating a NULL memory reference.
- */
- if (ip.c != TEE_MEMREF_NULL) {
- /*
- * If we fail to get a pointer to a shared
- * memory object (and increase the ref count)
- * from an identifier we return an error. All
- * pointers that has been added in params have
- * an increased ref count. It's the callers
- * responibility to do tee_shm_put() on all
- * resolved pointers.
- */
- shm = tee_shm_get_from_id(ctx, ip.c);
- if (IS_ERR(shm))
- return PTR_ERR(shm);
-
- /*
- * Ensure offset + size does not overflow
- * offset and does not overflow the size of
- * the referred shared memory object.
- */
- if ((ip.a + ip.b) < ip.a ||
- (ip.a + ip.b) > shm->size) {
- tee_shm_put(shm);
- return -EINVAL;
- }
- } else if (ctx->cap_memref_null) {
- /* Pass NULL pointer to OP-TEE */
- shm = NULL;
- } else {
- return -EINVAL;
- }
-
- params[n].u.memref.shm_offs = ip.a;
- params[n].u.memref.size = ip.b;
- params[n].u.memref.shm = shm;
+ rc = param_from_user_memref(ctx, ¶ms[n].u.memref,
+ &ip);
+ if (rc)
+ return rc;
break;
default:
/* Unknown attribute */
@@ -827,6 +889,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return tee_ioctl_shm_alloc(ctx, uarg);
case TEE_IOC_SHM_REGISTER:
return tee_ioctl_shm_register(ctx, uarg);
+ case TEE_IOC_SHM_REGISTER_FD:
+ return tee_ioctl_shm_register_fd(ctx, uarg);
case TEE_IOC_OPEN_SESSION:
return tee_ioctl_open_session(ctx, uarg);
case TEE_IOC_INVOKE:
@@ -1288,3 +1352,4 @@ MODULE_AUTHOR("Linaro");
MODULE_DESCRIPTION("TEE Driver");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("DMA_BUF");
diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
index 6c6ff5d5eed2..aad7f6c7e0f0 100644
--- a/drivers/tee/tee_private.h
+++ b/drivers/tee/tee_private.h
@@ -24,6 +24,7 @@ void teedev_ctx_put(struct tee_context *ctx);
struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
unsigned long addr, size_t length);
+struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs);
int tee_heap_update_from_dma_buf(struct tee_device *teedev,
struct dma_buf *dmabuf, size_t *offset,
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index daf6e5cfd59a..8b79918468b5 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -4,6 +4,7 @@
*/
#include <linux/anon_inodes.h>
#include <linux/device.h>
+#include <linux/dma-buf.h>
#include <linux/idr.h>
#include <linux/io.h>
#include <linux/mm.h>
@@ -15,6 +16,16 @@
#include <linux/highmem.h>
#include "tee_private.h"
+/* extra references appended to shm object for registered shared memory */
+struct tee_shm_dmabuf_ref {
+ struct tee_shm shm;
+ size_t offset;
+ struct dma_buf *dmabuf;
+ struct dma_buf_attachment *attach;
+ struct sg_table *sgt;
+ struct tee_shm *parent_shm;
+};
+
static void shm_put_kernel_pages(struct page **pages, size_t page_count)
{
size_t n;
@@ -45,7 +56,23 @@ static void release_registered_pages(struct tee_shm *shm)
static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
{
- if (shm->flags & TEE_SHM_POOL) {
+ struct tee_shm *parent_shm = NULL;
+ void *p = shm;
+
+ if (shm->flags & TEE_SHM_DMA_BUF) {
+ struct tee_shm_dmabuf_ref *ref;
+
+ ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
+ parent_shm = ref->parent_shm;
+ p = ref;
+ if (ref->attach) {
+ dma_buf_unmap_attachment(ref->attach, ref->sgt,
+ DMA_BIDIRECTIONAL);
+
+ dma_buf_detach(ref->dmabuf, ref->attach);
+ }
+ dma_buf_put(ref->dmabuf);
+ } else if (shm->flags & TEE_SHM_POOL) {
teedev->pool->ops->free(teedev->pool, shm);
} else if (shm->flags & TEE_SHM_DYNAMIC) {
int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
@@ -57,9 +84,10 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
release_registered_pages(shm);
}
- teedev_ctx_put(shm->ctx);
+ if (shm->ctx)
+ teedev_ctx_put(shm->ctx);
- kfree(shm);
+ kfree(p);
tee_device_put(teedev);
}
@@ -169,7 +197,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
* tee_client_invoke_func(). The memory allocated is later freed with a
* call to tee_shm_free().
*
- * @returns a pointer to 'struct tee_shm'
+ * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
*/
struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
{
@@ -179,6 +207,116 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
}
EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
+struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd)
+{
+ struct tee_shm_dmabuf_ref *ref;
+ int rc;
+
+ if (!tee_device_get(ctx->teedev))
+ return ERR_PTR(-EINVAL);
+
+ teedev_ctx_get(ctx);
+
+ ref = kzalloc(sizeof(*ref), GFP_KERNEL);
+ if (!ref) {
+ rc = -ENOMEM;
+ goto err_put_tee;
+ }
+
+ refcount_set(&ref->shm.refcount, 1);
+ ref->shm.ctx = ctx;
+ ref->shm.id = -1;
+ ref->shm.flags = TEE_SHM_DMA_BUF;
+
+ ref->dmabuf = dma_buf_get(fd);
+ if (IS_ERR(ref->dmabuf)) {
+ rc = PTR_ERR(ref->dmabuf);
+ goto err_kfree_ref;
+ }
+
+ rc = tee_heap_update_from_dma_buf(ctx->teedev, ref->dmabuf,
+ &ref->offset, &ref->shm,
+ &ref->parent_shm);
+ if (!rc)
+ goto out;
+ if (rc != -EINVAL)
+ goto err_put_dmabuf;
+
+ ref->attach = dma_buf_attach(ref->dmabuf, &ctx->teedev->dev);
+ if (IS_ERR(ref->attach)) {
+ rc = PTR_ERR(ref->attach);
+ goto err_put_dmabuf;
+ }
+
+ ref->sgt = dma_buf_map_attachment(ref->attach, DMA_BIDIRECTIONAL);
+ if (IS_ERR(ref->sgt)) {
+ rc = PTR_ERR(ref->sgt);
+ goto err_detach;
+ }
+
+ if (sg_nents(ref->sgt->sgl) != 1) {
+ rc = PTR_ERR(ref->sgt->sgl);
+ goto err_unmap_attachement;
+ }
+
+ ref->shm.paddr = page_to_phys(sg_page(ref->sgt->sgl));
+ ref->shm.size = ref->sgt->sgl->length;
+
+out:
+ mutex_lock(&ref->shm.ctx->teedev->mutex);
+ ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm,
+ 1, 0, GFP_KERNEL);
+ mutex_unlock(&ref->shm.ctx->teedev->mutex);
+ if (ref->shm.id < 0) {
+ rc = ref->shm.id;
+ if (ref->attach)
+ goto err_unmap_attachement;
+ goto err_put_dmabuf;
+ }
+
+ return &ref->shm;
+
+err_unmap_attachement:
+ dma_buf_unmap_attachment(ref->attach, ref->sgt, DMA_BIDIRECTIONAL);
+err_detach:
+ dma_buf_detach(ref->dmabuf, ref->attach);
+err_put_dmabuf:
+ dma_buf_put(ref->dmabuf);
+err_kfree_ref:
+ kfree(ref);
+err_put_tee:
+ teedev_ctx_put(ctx);
+ tee_device_put(ctx->teedev);
+
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(tee_shm_register_fd);
+
+struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs)
+{
+ struct tee_shm *parent_shm = NULL;
+
+ if (shm->flags & TEE_SHM_DMA_BUF) {
+ struct tee_shm_dmabuf_ref *ref;
+
+ ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
+ if (ref->parent_shm) {
+ /*
+ * the shm already has one reference to
+ * ref->parent_shm so we should be clear of 0.
+ * We're getting another reference since the caller
+ * of this function expects to put the returned
+ * parent_shm when it's done with it.
+ */
+ parent_shm = ref->parent_shm;
+ refcount_inc(&parent_shm->refcount);
+ *offs = ref->offset;
+ }
+ }
+
+ return parent_shm;
+}
+
/**
* tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
* kernel buffer
diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
index 16ef078247ae..6bd833b6d0e1 100644
--- a/include/linux/tee_core.h
+++ b/include/linux/tee_core.h
@@ -28,6 +28,7 @@
#define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user space */
#define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */
#define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */
+#define TEE_SHM_DMA_BUF BIT(4) /* Memory with dma-buf handle */
#define TEE_DEVICE_FLAG_REGISTERED 0x1
#define TEE_MAX_DEV_NAME_LEN 32
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index a54c203000ed..824f1251de60 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -116,6 +116,16 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
void *addr, size_t length);
+/**
+ * tee_shm_register_fd() - Register shared memory from file descriptor
+ *
+ * @ctx: Context that allocates the shared memory
+ * @fd: Shared memory file descriptor reference
+ *
+ * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
+ */
+struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd);
+
/**
* tee_shm_free() - Free shared memory
* @shm: Handle to shared memory to free
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index d0430bee8292..1f9a4ac2b211 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -118,6 +118,35 @@ struct tee_ioctl_shm_alloc_data {
#define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, \
struct tee_ioctl_shm_alloc_data)
+/**
+ * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument
+ * @fd: [in] File descriptor identifying the shared memory
+ * @size: [out] Size of shared memory to allocate
+ * @flags: [in] Flags to/from allocation.
+ * @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_FD below.
+ */
+struct tee_ioctl_shm_register_fd_data {
+ __s64 fd;
+ __u64 size;
+ __u32 flags;
+ __s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file descriptor
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The returned file descriptor refers to the shared memory object in kernel
+ * land. The shared memory is freed when the descriptor is closed.
+ */
+#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 8, \
+ struct tee_ioctl_shm_register_fd_data)
+
/**
* struct tee_ioctl_buf_data - Variable sized buffer
* @buf_ptr: [in] A __user pointer to a buffer
--
2.43.0Hi Jens,
On Wed, Mar 05, 2025 at 02:04:12PM +0100, Jens Wiklander wrote:
> From: Etienne Carriere <etienne.carriere@linaro.org>
>
> Enable userspace to create a tee_shm object that refers to a dmabuf
> reference.
>
> Userspace registers the dmabuf file descriptor as in a tee_shm object.
> The registration is completed with a tee_shm file descriptor returned to
> userspace.
>
> Userspace is free to close the dmabuf file descriptor now since all the
> resources are now held via the tee_shm object.
>
> Closing the tee_shm file descriptor will release all resources used by the
> tee_shm object.
>
> This change only support dmabuf references that relates to physically
> contiguous memory buffers.
>
> New tee_shm flag to identify tee_shm objects built from a registered
> dmabuf, TEE_SHM_DMA_BUF.
>
> Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> Signed-off-by: Olivier Masse <olivier.masse@nxp.com>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
> drivers/tee/tee_core.c | 145 ++++++++++++++++++++++++++-----------
> drivers/tee/tee_private.h | 1 +
> drivers/tee/tee_shm.c | 146 ++++++++++++++++++++++++++++++++++++--
> include/linux/tee_core.h | 1 +
> include/linux/tee_drv.h | 10 +++
> include/uapi/linux/tee.h | 29 ++++++++
> 6 files changed, 288 insertions(+), 44 deletions(-)
>
I am still trying to find if we really need a separate IOCTL to register
DMA heap with TEE subsystem. Can't we initialize tee_shm as a member of
struct tee_heap_buffer in tee_dma_heap_alloc() where the allocation
happens? We can always find a reference back to tee_shm object from DMA
buffer.
-Sumit
> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> index 685afcaa3ea1..3a71643766d5 100644
> --- a/drivers/tee/tee_core.c
> +++ b/drivers/tee/tee_core.c
> @@ -353,6 +353,103 @@ tee_ioctl_shm_register(struct tee_context *ctx,
> return ret;
> }
>
> +static int
> +tee_ioctl_shm_register_fd(struct tee_context *ctx,
> + struct tee_ioctl_shm_register_fd_data __user *udata)
> +{
> + struct tee_ioctl_shm_register_fd_data data;
> + struct tee_shm *shm;
> + long ret;
> +
> + 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_fd(ctx, data.fd);
> + if (IS_ERR(shm))
> + return -EINVAL;
> +
> + data.id = shm->id;
> + data.flags = shm->flags;
> + data.size = 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 param_from_user_memref(struct tee_context *ctx,
> + struct tee_param_memref *memref,
> + struct tee_ioctl_param *ip)
> +{
> + struct tee_shm *shm;
> + size_t offs = 0;
> +
> + /*
> + * If a NULL pointer is passed to a TA in the TEE,
> + * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> + * indicating a NULL memory reference.
> + */
> + if (ip->c != TEE_MEMREF_NULL) {
> + /*
> + * If we fail to get a pointer to a shared
> + * memory object (and increase the ref count)
> + * from an identifier we return an error. All
> + * pointers that has been added in params have
> + * an increased ref count. It's the callers
> + * responibility to do tee_shm_put() on all
> + * resolved pointers.
> + */
> + shm = tee_shm_get_from_id(ctx, ip->c);
> + if (IS_ERR(shm))
> + return PTR_ERR(shm);
> +
> + /*
> + * Ensure offset + size does not overflow
> + * offset and does not overflow the size of
> + * the referred shared memory object.
> + */
> + if ((ip->a + ip->b) < ip->a ||
> + (ip->a + ip->b) > shm->size) {
> + tee_shm_put(shm);
> + return -EINVAL;
> + }
> +
> + if (shm->flags & TEE_SHM_DMA_BUF) {
> + struct tee_shm *parent_shm;
> +
> + parent_shm = tee_shm_get_parent_shm(shm, &offs);
> + if (parent_shm) {
> + tee_shm_put(shm);
> + shm = parent_shm;
> + }
> + }
> + } else if (ctx->cap_memref_null) {
> + /* Pass NULL pointer to OP-TEE */
> + shm = NULL;
> + } else {
> + return -EINVAL;
> + }
> +
> + memref->shm_offs = ip->a + offs;
> + memref->size = ip->b;
> + memref->shm = shm;
> +
> + return 0;
> +}
> +
> static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> size_t num_params,
> struct tee_ioctl_param __user *uparams)
> @@ -360,8 +457,8 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> size_t n;
>
> for (n = 0; n < num_params; n++) {
> - struct tee_shm *shm;
> struct tee_ioctl_param ip;
> + int rc;
>
> if (copy_from_user(&ip, uparams + n, sizeof(ip)))
> return -EFAULT;
> @@ -384,45 +481,10 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
> case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
> case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
> - /*
> - * If a NULL pointer is passed to a TA in the TEE,
> - * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> - * indicating a NULL memory reference.
> - */
> - if (ip.c != TEE_MEMREF_NULL) {
> - /*
> - * If we fail to get a pointer to a shared
> - * memory object (and increase the ref count)
> - * from an identifier we return an error. All
> - * pointers that has been added in params have
> - * an increased ref count. It's the callers
> - * responibility to do tee_shm_put() on all
> - * resolved pointers.
> - */
> - shm = tee_shm_get_from_id(ctx, ip.c);
> - if (IS_ERR(shm))
> - return PTR_ERR(shm);
> -
> - /*
> - * Ensure offset + size does not overflow
> - * offset and does not overflow the size of
> - * the referred shared memory object.
> - */
> - if ((ip.a + ip.b) < ip.a ||
> - (ip.a + ip.b) > shm->size) {
> - tee_shm_put(shm);
> - return -EINVAL;
> - }
> - } else if (ctx->cap_memref_null) {
> - /* Pass NULL pointer to OP-TEE */
> - shm = NULL;
> - } else {
> - return -EINVAL;
> - }
> -
> - params[n].u.memref.shm_offs = ip.a;
> - params[n].u.memref.size = ip.b;
> - params[n].u.memref.shm = shm;
> + rc = param_from_user_memref(ctx, ¶ms[n].u.memref,
> + &ip);
> + if (rc)
> + return rc;
> break;
> default:
> /* Unknown attribute */
> @@ -827,6 +889,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> return tee_ioctl_shm_alloc(ctx, uarg);
> case TEE_IOC_SHM_REGISTER:
> return tee_ioctl_shm_register(ctx, uarg);
> + case TEE_IOC_SHM_REGISTER_FD:
> + return tee_ioctl_shm_register_fd(ctx, uarg);
> case TEE_IOC_OPEN_SESSION:
> return tee_ioctl_open_session(ctx, uarg);
> case TEE_IOC_INVOKE:
> @@ -1288,3 +1352,4 @@ MODULE_AUTHOR("Linaro");
> MODULE_DESCRIPTION("TEE Driver");
> MODULE_VERSION("1.0");
> MODULE_LICENSE("GPL v2");
> +MODULE_IMPORT_NS("DMA_BUF");
> diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
> index 6c6ff5d5eed2..aad7f6c7e0f0 100644
> --- a/drivers/tee/tee_private.h
> +++ b/drivers/tee/tee_private.h
> @@ -24,6 +24,7 @@ void teedev_ctx_put(struct tee_context *ctx);
> struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
> struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> unsigned long addr, size_t length);
> +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs);
>
> int tee_heap_update_from_dma_buf(struct tee_device *teedev,
> struct dma_buf *dmabuf, size_t *offset,
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index daf6e5cfd59a..8b79918468b5 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -4,6 +4,7 @@
> */
> #include <linux/anon_inodes.h>
> #include <linux/device.h>
> +#include <linux/dma-buf.h>
> #include <linux/idr.h>
> #include <linux/io.h>
> #include <linux/mm.h>
> @@ -15,6 +16,16 @@
> #include <linux/highmem.h>
> #include "tee_private.h"
>
> +/* extra references appended to shm object for registered shared memory */
> +struct tee_shm_dmabuf_ref {
> + struct tee_shm shm;
> + size_t offset;
> + struct dma_buf *dmabuf;
> + struct dma_buf_attachment *attach;
> + struct sg_table *sgt;
> + struct tee_shm *parent_shm;
> +};
> +
> static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> {
> size_t n;
> @@ -45,7 +56,23 @@ static void release_registered_pages(struct tee_shm *shm)
>
> static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> {
> - if (shm->flags & TEE_SHM_POOL) {
> + struct tee_shm *parent_shm = NULL;
> + void *p = shm;
> +
> + if (shm->flags & TEE_SHM_DMA_BUF) {
> + struct tee_shm_dmabuf_ref *ref;
> +
> + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> + parent_shm = ref->parent_shm;
> + p = ref;
> + if (ref->attach) {
> + dma_buf_unmap_attachment(ref->attach, ref->sgt,
> + DMA_BIDIRECTIONAL);
> +
> + dma_buf_detach(ref->dmabuf, ref->attach);
> + }
> + dma_buf_put(ref->dmabuf);
> + } else if (shm->flags & TEE_SHM_POOL) {
> teedev->pool->ops->free(teedev->pool, shm);
> } else if (shm->flags & TEE_SHM_DYNAMIC) {
> int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
> @@ -57,9 +84,10 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> release_registered_pages(shm);
> }
>
> - teedev_ctx_put(shm->ctx);
> + if (shm->ctx)
> + teedev_ctx_put(shm->ctx);
>
> - kfree(shm);
> + kfree(p);
>
> tee_device_put(teedev);
> }
> @@ -169,7 +197,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
> * tee_client_invoke_func(). The memory allocated is later freed with a
> * call to tee_shm_free().
> *
> - * @returns a pointer to 'struct tee_shm'
> + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> */
> struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> {
> @@ -179,6 +207,116 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> }
> EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
>
> +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd)
> +{
> + struct tee_shm_dmabuf_ref *ref;
> + int rc;
> +
> + if (!tee_device_get(ctx->teedev))
> + return ERR_PTR(-EINVAL);
> +
> + teedev_ctx_get(ctx);
> +
> + ref = kzalloc(sizeof(*ref), GFP_KERNEL);
> + if (!ref) {
> + rc = -ENOMEM;
> + goto err_put_tee;
> + }
> +
> + refcount_set(&ref->shm.refcount, 1);
> + ref->shm.ctx = ctx;
> + ref->shm.id = -1;
> + ref->shm.flags = TEE_SHM_DMA_BUF;
> +
> + ref->dmabuf = dma_buf_get(fd);
> + if (IS_ERR(ref->dmabuf)) {
> + rc = PTR_ERR(ref->dmabuf);
> + goto err_kfree_ref;
> + }
> +
> + rc = tee_heap_update_from_dma_buf(ctx->teedev, ref->dmabuf,
> + &ref->offset, &ref->shm,
> + &ref->parent_shm);
> + if (!rc)
> + goto out;
> + if (rc != -EINVAL)
> + goto err_put_dmabuf;
> +
> + ref->attach = dma_buf_attach(ref->dmabuf, &ctx->teedev->dev);
> + if (IS_ERR(ref->attach)) {
> + rc = PTR_ERR(ref->attach);
> + goto err_put_dmabuf;
> + }
> +
> + ref->sgt = dma_buf_map_attachment(ref->attach, DMA_BIDIRECTIONAL);
> + if (IS_ERR(ref->sgt)) {
> + rc = PTR_ERR(ref->sgt);
> + goto err_detach;
> + }
> +
> + if (sg_nents(ref->sgt->sgl) != 1) {
> + rc = PTR_ERR(ref->sgt->sgl);
> + goto err_unmap_attachement;
> + }
> +
> + ref->shm.paddr = page_to_phys(sg_page(ref->sgt->sgl));
> + ref->shm.size = ref->sgt->sgl->length;
> +
> +out:
> + mutex_lock(&ref->shm.ctx->teedev->mutex);
> + ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm,
> + 1, 0, GFP_KERNEL);
> + mutex_unlock(&ref->shm.ctx->teedev->mutex);
> + if (ref->shm.id < 0) {
> + rc = ref->shm.id;
> + if (ref->attach)
> + goto err_unmap_attachement;
> + goto err_put_dmabuf;
> + }
> +
> + return &ref->shm;
> +
> +err_unmap_attachement:
> + dma_buf_unmap_attachment(ref->attach, ref->sgt, DMA_BIDIRECTIONAL);
> +err_detach:
> + dma_buf_detach(ref->dmabuf, ref->attach);
> +err_put_dmabuf:
> + dma_buf_put(ref->dmabuf);
> +err_kfree_ref:
> + kfree(ref);
> +err_put_tee:
> + teedev_ctx_put(ctx);
> + tee_device_put(ctx->teedev);
> +
> + return ERR_PTR(rc);
> +}
> +EXPORT_SYMBOL_GPL(tee_shm_register_fd);
> +
> +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs)
> +{
> + struct tee_shm *parent_shm = NULL;
> +
> + if (shm->flags & TEE_SHM_DMA_BUF) {
> + struct tee_shm_dmabuf_ref *ref;
> +
> + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> + if (ref->parent_shm) {
> + /*
> + * the shm already has one reference to
> + * ref->parent_shm so we should be clear of 0.
> + * We're getting another reference since the caller
> + * of this function expects to put the returned
> + * parent_shm when it's done with it.
> + */
> + parent_shm = ref->parent_shm;
> + refcount_inc(&parent_shm->refcount);
> + *offs = ref->offset;
> + }
> + }
> +
> + return parent_shm;
> +}
> +
> /**
> * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
> * kernel buffer
> diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
> index 16ef078247ae..6bd833b6d0e1 100644
> --- a/include/linux/tee_core.h
> +++ b/include/linux/tee_core.h
> @@ -28,6 +28,7 @@
> #define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user space */
> #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */
> #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */
> +#define TEE_SHM_DMA_BUF BIT(4) /* Memory with dma-buf handle */
>
> #define TEE_DEVICE_FLAG_REGISTERED 0x1
> #define TEE_MAX_DEV_NAME_LEN 32
> diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> index a54c203000ed..824f1251de60 100644
> --- a/include/linux/tee_drv.h
> +++ b/include/linux/tee_drv.h
> @@ -116,6 +116,16 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
> struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> void *addr, size_t length);
>
> +/**
> + * tee_shm_register_fd() - Register shared memory from file descriptor
> + *
> + * @ctx: Context that allocates the shared memory
> + * @fd: Shared memory file descriptor reference
> + *
> + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> + */
> +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd);
> +
> /**
> * tee_shm_free() - Free shared memory
> * @shm: Handle to shared memory to free
> diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
> index d0430bee8292..1f9a4ac2b211 100644
> --- a/include/uapi/linux/tee.h
> +++ b/include/uapi/linux/tee.h
> @@ -118,6 +118,35 @@ struct tee_ioctl_shm_alloc_data {
> #define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, \
> struct tee_ioctl_shm_alloc_data)
>
> +/**
> + * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument
> + * @fd: [in] File descriptor identifying the shared memory
> + * @size: [out] Size of shared memory to allocate
> + * @flags: [in] Flags to/from allocation.
> + * @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_FD below.
> + */
> +struct tee_ioctl_shm_register_fd_data {
> + __s64 fd;
> + __u64 size;
> + __u32 flags;
> + __s32 id;
> +};
> +
> +/**
> + * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file descriptor
> + *
> + * Returns a file descriptor on success or < 0 on failure
> + *
> + * The returned file descriptor refers to the shared memory object in kernel
> + * land. The shared memory is freed when the descriptor is closed.
> + */
> +#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 8, \
> + struct tee_ioctl_shm_register_fd_data)
> +
> /**
> * struct tee_ioctl_buf_data - Variable sized buffer
> * @buf_ptr: [in] A __user pointer to a buffer
> --
> 2.43.0
>
Hi Sumit,
On Tue, Mar 25, 2025 at 7:50 AM Sumit Garg <sumit.garg@kernel.org> wrote:
>
> Hi Jens,
>
> On Wed, Mar 05, 2025 at 02:04:12PM +0100, Jens Wiklander wrote:
> > From: Etienne Carriere <etienne.carriere@linaro.org>
> >
> > Enable userspace to create a tee_shm object that refers to a dmabuf
> > reference.
> >
> > Userspace registers the dmabuf file descriptor as in a tee_shm object.
> > The registration is completed with a tee_shm file descriptor returned to
> > userspace.
> >
> > Userspace is free to close the dmabuf file descriptor now since all the
> > resources are now held via the tee_shm object.
> >
> > Closing the tee_shm file descriptor will release all resources used by the
> > tee_shm object.
> >
> > This change only support dmabuf references that relates to physically
> > contiguous memory buffers.
> >
> > New tee_shm flag to identify tee_shm objects built from a registered
> > dmabuf, TEE_SHM_DMA_BUF.
> >
> > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > Signed-off-by: Olivier Masse <olivier.masse@nxp.com>
> > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > ---
> > drivers/tee/tee_core.c | 145 ++++++++++++++++++++++++++-----------
> > drivers/tee/tee_private.h | 1 +
> > drivers/tee/tee_shm.c | 146 ++++++++++++++++++++++++++++++++++++--
> > include/linux/tee_core.h | 1 +
> > include/linux/tee_drv.h | 10 +++
> > include/uapi/linux/tee.h | 29 ++++++++
> > 6 files changed, 288 insertions(+), 44 deletions(-)
> >
>
> I am still trying to find if we really need a separate IOCTL to register
> DMA heap with TEE subsystem. Can't we initialize tee_shm as a member of
> struct tee_heap_buffer in tee_dma_heap_alloc() where the allocation
> happens?
No, that's not possible since we don't have a tee_context availble so
we can't assign an ID that userspace can use for this shm object.
We could add new attribute types TEE_IOCTL_PARAM_ATTR_TYPE_MEMFD_*,
but it's a bit more complicated than that since we'd also need to
update for the life cycle.
> We can always find a reference back to tee_shm object from DMA
> buffer.
Yes
Cheers,
Jens
>
> -Sumit
>
> > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> > index 685afcaa3ea1..3a71643766d5 100644
> > --- a/drivers/tee/tee_core.c
> > +++ b/drivers/tee/tee_core.c
> > @@ -353,6 +353,103 @@ tee_ioctl_shm_register(struct tee_context *ctx,
> > return ret;
> > }
> >
> > +static int
> > +tee_ioctl_shm_register_fd(struct tee_context *ctx,
> > + struct tee_ioctl_shm_register_fd_data __user *udata)
> > +{
> > + struct tee_ioctl_shm_register_fd_data data;
> > + struct tee_shm *shm;
> > + long ret;
> > +
> > + 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_fd(ctx, data.fd);
> > + if (IS_ERR(shm))
> > + return -EINVAL;
> > +
> > + data.id = shm->id;
> > + data.flags = shm->flags;
> > + data.size = 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 param_from_user_memref(struct tee_context *ctx,
> > + struct tee_param_memref *memref,
> > + struct tee_ioctl_param *ip)
> > +{
> > + struct tee_shm *shm;
> > + size_t offs = 0;
> > +
> > + /*
> > + * If a NULL pointer is passed to a TA in the TEE,
> > + * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> > + * indicating a NULL memory reference.
> > + */
> > + if (ip->c != TEE_MEMREF_NULL) {
> > + /*
> > + * If we fail to get a pointer to a shared
> > + * memory object (and increase the ref count)
> > + * from an identifier we return an error. All
> > + * pointers that has been added in params have
> > + * an increased ref count. It's the callers
> > + * responibility to do tee_shm_put() on all
> > + * resolved pointers.
> > + */
> > + shm = tee_shm_get_from_id(ctx, ip->c);
> > + if (IS_ERR(shm))
> > + return PTR_ERR(shm);
> > +
> > + /*
> > + * Ensure offset + size does not overflow
> > + * offset and does not overflow the size of
> > + * the referred shared memory object.
> > + */
> > + if ((ip->a + ip->b) < ip->a ||
> > + (ip->a + ip->b) > shm->size) {
> > + tee_shm_put(shm);
> > + return -EINVAL;
> > + }
> > +
> > + if (shm->flags & TEE_SHM_DMA_BUF) {
> > + struct tee_shm *parent_shm;
> > +
> > + parent_shm = tee_shm_get_parent_shm(shm, &offs);
> > + if (parent_shm) {
> > + tee_shm_put(shm);
> > + shm = parent_shm;
> > + }
> > + }
> > + } else if (ctx->cap_memref_null) {
> > + /* Pass NULL pointer to OP-TEE */
> > + shm = NULL;
> > + } else {
> > + return -EINVAL;
> > + }
> > +
> > + memref->shm_offs = ip->a + offs;
> > + memref->size = ip->b;
> > + memref->shm = shm;
> > +
> > + return 0;
> > +}
> > +
> > static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > size_t num_params,
> > struct tee_ioctl_param __user *uparams)
> > @@ -360,8 +457,8 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > size_t n;
> >
> > for (n = 0; n < num_params; n++) {
> > - struct tee_shm *shm;
> > struct tee_ioctl_param ip;
> > + int rc;
> >
> > if (copy_from_user(&ip, uparams + n, sizeof(ip)))
> > return -EFAULT;
> > @@ -384,45 +481,10 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
> > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
> > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
> > - /*
> > - * If a NULL pointer is passed to a TA in the TEE,
> > - * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> > - * indicating a NULL memory reference.
> > - */
> > - if (ip.c != TEE_MEMREF_NULL) {
> > - /*
> > - * If we fail to get a pointer to a shared
> > - * memory object (and increase the ref count)
> > - * from an identifier we return an error. All
> > - * pointers that has been added in params have
> > - * an increased ref count. It's the callers
> > - * responibility to do tee_shm_put() on all
> > - * resolved pointers.
> > - */
> > - shm = tee_shm_get_from_id(ctx, ip.c);
> > - if (IS_ERR(shm))
> > - return PTR_ERR(shm);
> > -
> > - /*
> > - * Ensure offset + size does not overflow
> > - * offset and does not overflow the size of
> > - * the referred shared memory object.
> > - */
> > - if ((ip.a + ip.b) < ip.a ||
> > - (ip.a + ip.b) > shm->size) {
> > - tee_shm_put(shm);
> > - return -EINVAL;
> > - }
> > - } else if (ctx->cap_memref_null) {
> > - /* Pass NULL pointer to OP-TEE */
> > - shm = NULL;
> > - } else {
> > - return -EINVAL;
> > - }
> > -
> > - params[n].u.memref.shm_offs = ip.a;
> > - params[n].u.memref.size = ip.b;
> > - params[n].u.memref.shm = shm;
> > + rc = param_from_user_memref(ctx, ¶ms[n].u.memref,
> > + &ip);
> > + if (rc)
> > + return rc;
> > break;
> > default:
> > /* Unknown attribute */
> > @@ -827,6 +889,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> > return tee_ioctl_shm_alloc(ctx, uarg);
> > case TEE_IOC_SHM_REGISTER:
> > return tee_ioctl_shm_register(ctx, uarg);
> > + case TEE_IOC_SHM_REGISTER_FD:
> > + return tee_ioctl_shm_register_fd(ctx, uarg);
> > case TEE_IOC_OPEN_SESSION:
> > return tee_ioctl_open_session(ctx, uarg);
> > case TEE_IOC_INVOKE:
> > @@ -1288,3 +1352,4 @@ MODULE_AUTHOR("Linaro");
> > MODULE_DESCRIPTION("TEE Driver");
> > MODULE_VERSION("1.0");
> > MODULE_LICENSE("GPL v2");
> > +MODULE_IMPORT_NS("DMA_BUF");
> > diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
> > index 6c6ff5d5eed2..aad7f6c7e0f0 100644
> > --- a/drivers/tee/tee_private.h
> > +++ b/drivers/tee/tee_private.h
> > @@ -24,6 +24,7 @@ void teedev_ctx_put(struct tee_context *ctx);
> > struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
> > struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> > unsigned long addr, size_t length);
> > +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs);
> >
> > int tee_heap_update_from_dma_buf(struct tee_device *teedev,
> > struct dma_buf *dmabuf, size_t *offset,
> > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> > index daf6e5cfd59a..8b79918468b5 100644
> > --- a/drivers/tee/tee_shm.c
> > +++ b/drivers/tee/tee_shm.c
> > @@ -4,6 +4,7 @@
> > */
> > #include <linux/anon_inodes.h>
> > #include <linux/device.h>
> > +#include <linux/dma-buf.h>
> > #include <linux/idr.h>
> > #include <linux/io.h>
> > #include <linux/mm.h>
> > @@ -15,6 +16,16 @@
> > #include <linux/highmem.h>
> > #include "tee_private.h"
> >
> > +/* extra references appended to shm object for registered shared memory */
> > +struct tee_shm_dmabuf_ref {
> > + struct tee_shm shm;
> > + size_t offset;
> > + struct dma_buf *dmabuf;
> > + struct dma_buf_attachment *attach;
> > + struct sg_table *sgt;
> > + struct tee_shm *parent_shm;
> > +};
> > +
> > static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> > {
> > size_t n;
> > @@ -45,7 +56,23 @@ static void release_registered_pages(struct tee_shm *shm)
> >
> > static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> > {
> > - if (shm->flags & TEE_SHM_POOL) {
> > + struct tee_shm *parent_shm = NULL;
> > + void *p = shm;
> > +
> > + if (shm->flags & TEE_SHM_DMA_BUF) {
> > + struct tee_shm_dmabuf_ref *ref;
> > +
> > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> > + parent_shm = ref->parent_shm;
> > + p = ref;
> > + if (ref->attach) {
> > + dma_buf_unmap_attachment(ref->attach, ref->sgt,
> > + DMA_BIDIRECTIONAL);
> > +
> > + dma_buf_detach(ref->dmabuf, ref->attach);
> > + }
> > + dma_buf_put(ref->dmabuf);
> > + } else if (shm->flags & TEE_SHM_POOL) {
> > teedev->pool->ops->free(teedev->pool, shm);
> > } else if (shm->flags & TEE_SHM_DYNAMIC) {
> > int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
> > @@ -57,9 +84,10 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> > release_registered_pages(shm);
> > }
> >
> > - teedev_ctx_put(shm->ctx);
> > + if (shm->ctx)
> > + teedev_ctx_put(shm->ctx);
> >
> > - kfree(shm);
> > + kfree(p);
> >
> > tee_device_put(teedev);
> > }
> > @@ -169,7 +197,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
> > * tee_client_invoke_func(). The memory allocated is later freed with a
> > * call to tee_shm_free().
> > *
> > - * @returns a pointer to 'struct tee_shm'
> > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> > */
> > struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> > {
> > @@ -179,6 +207,116 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> > }
> > EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
> >
> > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd)
> > +{
> > + struct tee_shm_dmabuf_ref *ref;
> > + int rc;
> > +
> > + if (!tee_device_get(ctx->teedev))
> > + return ERR_PTR(-EINVAL);
> > +
> > + teedev_ctx_get(ctx);
> > +
> > + ref = kzalloc(sizeof(*ref), GFP_KERNEL);
> > + if (!ref) {
> > + rc = -ENOMEM;
> > + goto err_put_tee;
> > + }
> > +
> > + refcount_set(&ref->shm.refcount, 1);
> > + ref->shm.ctx = ctx;
> > + ref->shm.id = -1;
> > + ref->shm.flags = TEE_SHM_DMA_BUF;
> > +
> > + ref->dmabuf = dma_buf_get(fd);
> > + if (IS_ERR(ref->dmabuf)) {
> > + rc = PTR_ERR(ref->dmabuf);
> > + goto err_kfree_ref;
> > + }
> > +
> > + rc = tee_heap_update_from_dma_buf(ctx->teedev, ref->dmabuf,
> > + &ref->offset, &ref->shm,
> > + &ref->parent_shm);
> > + if (!rc)
> > + goto out;
> > + if (rc != -EINVAL)
> > + goto err_put_dmabuf;
> > +
> > + ref->attach = dma_buf_attach(ref->dmabuf, &ctx->teedev->dev);
> > + if (IS_ERR(ref->attach)) {
> > + rc = PTR_ERR(ref->attach);
> > + goto err_put_dmabuf;
> > + }
> > +
> > + ref->sgt = dma_buf_map_attachment(ref->attach, DMA_BIDIRECTIONAL);
> > + if (IS_ERR(ref->sgt)) {
> > + rc = PTR_ERR(ref->sgt);
> > + goto err_detach;
> > + }
> > +
> > + if (sg_nents(ref->sgt->sgl) != 1) {
> > + rc = PTR_ERR(ref->sgt->sgl);
> > + goto err_unmap_attachement;
> > + }
> > +
> > + ref->shm.paddr = page_to_phys(sg_page(ref->sgt->sgl));
> > + ref->shm.size = ref->sgt->sgl->length;
> > +
> > +out:
> > + mutex_lock(&ref->shm.ctx->teedev->mutex);
> > + ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm,
> > + 1, 0, GFP_KERNEL);
> > + mutex_unlock(&ref->shm.ctx->teedev->mutex);
> > + if (ref->shm.id < 0) {
> > + rc = ref->shm.id;
> > + if (ref->attach)
> > + goto err_unmap_attachement;
> > + goto err_put_dmabuf;
> > + }
> > +
> > + return &ref->shm;
> > +
> > +err_unmap_attachement:
> > + dma_buf_unmap_attachment(ref->attach, ref->sgt, DMA_BIDIRECTIONAL);
> > +err_detach:
> > + dma_buf_detach(ref->dmabuf, ref->attach);
> > +err_put_dmabuf:
> > + dma_buf_put(ref->dmabuf);
> > +err_kfree_ref:
> > + kfree(ref);
> > +err_put_tee:
> > + teedev_ctx_put(ctx);
> > + tee_device_put(ctx->teedev);
> > +
> > + return ERR_PTR(rc);
> > +}
> > +EXPORT_SYMBOL_GPL(tee_shm_register_fd);
> > +
> > +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs)
> > +{
> > + struct tee_shm *parent_shm = NULL;
> > +
> > + if (shm->flags & TEE_SHM_DMA_BUF) {
> > + struct tee_shm_dmabuf_ref *ref;
> > +
> > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> > + if (ref->parent_shm) {
> > + /*
> > + * the shm already has one reference to
> > + * ref->parent_shm so we should be clear of 0.
> > + * We're getting another reference since the caller
> > + * of this function expects to put the returned
> > + * parent_shm when it's done with it.
> > + */
> > + parent_shm = ref->parent_shm;
> > + refcount_inc(&parent_shm->refcount);
> > + *offs = ref->offset;
> > + }
> > + }
> > +
> > + return parent_shm;
> > +}
> > +
> > /**
> > * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
> > * kernel buffer
> > diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
> > index 16ef078247ae..6bd833b6d0e1 100644
> > --- a/include/linux/tee_core.h
> > +++ b/include/linux/tee_core.h
> > @@ -28,6 +28,7 @@
> > #define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user space */
> > #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */
> > #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */
> > +#define TEE_SHM_DMA_BUF BIT(4) /* Memory with dma-buf handle */
> >
> > #define TEE_DEVICE_FLAG_REGISTERED 0x1
> > #define TEE_MAX_DEV_NAME_LEN 32
> > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> > index a54c203000ed..824f1251de60 100644
> > --- a/include/linux/tee_drv.h
> > +++ b/include/linux/tee_drv.h
> > @@ -116,6 +116,16 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
> > struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> > void *addr, size_t length);
> >
> > +/**
> > + * tee_shm_register_fd() - Register shared memory from file descriptor
> > + *
> > + * @ctx: Context that allocates the shared memory
> > + * @fd: Shared memory file descriptor reference
> > + *
> > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> > + */
> > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd);
> > +
> > /**
> > * tee_shm_free() - Free shared memory
> > * @shm: Handle to shared memory to free
> > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
> > index d0430bee8292..1f9a4ac2b211 100644
> > --- a/include/uapi/linux/tee.h
> > +++ b/include/uapi/linux/tee.h
> > @@ -118,6 +118,35 @@ struct tee_ioctl_shm_alloc_data {
> > #define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, \
> > struct tee_ioctl_shm_alloc_data)
> >
> > +/**
> > + * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument
> > + * @fd: [in] File descriptor identifying the shared memory
> > + * @size: [out] Size of shared memory to allocate
> > + * @flags: [in] Flags to/from allocation.
> > + * @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_FD below.
> > + */
> > +struct tee_ioctl_shm_register_fd_data {
> > + __s64 fd;
> > + __u64 size;
> > + __u32 flags;
> > + __s32 id;
> > +};
> > +
> > +/**
> > + * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file descriptor
> > + *
> > + * Returns a file descriptor on success or < 0 on failure
> > + *
> > + * The returned file descriptor refers to the shared memory object in kernel
> > + * land. The shared memory is freed when the descriptor is closed.
> > + */
> > +#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 8, \
> > + struct tee_ioctl_shm_register_fd_data)
> > +
> > /**
> > * struct tee_ioctl_buf_data - Variable sized buffer
> > * @buf_ptr: [in] A __user pointer to a buffer
> > --
> > 2.43.0
> >
On Tue, Mar 25, 2025 at 12:17:20PM +0100, Jens Wiklander wrote:
> Hi Sumit,
>
> On Tue, Mar 25, 2025 at 7:50 AM Sumit Garg <sumit.garg@kernel.org> wrote:
> >
> > Hi Jens,
> >
> > On Wed, Mar 05, 2025 at 02:04:12PM +0100, Jens Wiklander wrote:
> > > From: Etienne Carriere <etienne.carriere@linaro.org>
> > >
> > > Enable userspace to create a tee_shm object that refers to a dmabuf
> > > reference.
> > >
> > > Userspace registers the dmabuf file descriptor as in a tee_shm object.
> > > The registration is completed with a tee_shm file descriptor returned to
> > > userspace.
> > >
> > > Userspace is free to close the dmabuf file descriptor now since all the
> > > resources are now held via the tee_shm object.
> > >
> > > Closing the tee_shm file descriptor will release all resources used by the
> > > tee_shm object.
> > >
> > > This change only support dmabuf references that relates to physically
> > > contiguous memory buffers.
Let's try to reframe this commit message to say that new ioctl allows to
register DMA buffers allocated from restricted/protected heaps with TEE
subsystem.
> > >
> > > New tee_shm flag to identify tee_shm objects built from a registered
> > > dmabuf, TEE_SHM_DMA_BUF.
> > >
> > > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > > Signed-off-by: Olivier Masse <olivier.masse@nxp.com>
> > > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > > ---
> > > drivers/tee/tee_core.c | 145 ++++++++++++++++++++++++++-----------
> > > drivers/tee/tee_private.h | 1 +
> > > drivers/tee/tee_shm.c | 146 ++++++++++++++++++++++++++++++++++++--
> > > include/linux/tee_core.h | 1 +
> > > include/linux/tee_drv.h | 10 +++
> > > include/uapi/linux/tee.h | 29 ++++++++
> > > 6 files changed, 288 insertions(+), 44 deletions(-)
> > >
> >
> > I am still trying to find if we really need a separate IOCTL to register
> > DMA heap with TEE subsystem. Can't we initialize tee_shm as a member of
> > struct tee_heap_buffer in tee_dma_heap_alloc() where the allocation
> > happens?
>
> No, that's not possible since we don't have a tee_context availble so
> we can't assign an ID that userspace can use for this shm object.
>
> We could add new attribute types TEE_IOCTL_PARAM_ATTR_TYPE_MEMFD_*,
> but it's a bit more complicated than that since we'd also need to
> update for the life cycle.
Okay, that's fair enough. Lets take this new IOCTL approach then.
>
>
> > We can always find a reference back to tee_shm object from DMA
> > buffer.
>
> Yes
>
> Cheers,
> Jens
>
> >
> > -Sumit
> >
> > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> > > index 685afcaa3ea1..3a71643766d5 100644
> > > --- a/drivers/tee/tee_core.c
> > > +++ b/drivers/tee/tee_core.c
> > > @@ -353,6 +353,103 @@ tee_ioctl_shm_register(struct tee_context *ctx,
> > > return ret;
> > > }
> > >
> > > +static int
> > > +tee_ioctl_shm_register_fd(struct tee_context *ctx,
> > > + struct tee_ioctl_shm_register_fd_data __user *udata)
> > > +{
> > > + struct tee_ioctl_shm_register_fd_data data;
> > > + struct tee_shm *shm;
> > > + long ret;
> > > +
> > > + 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_fd(ctx, data.fd);
> > > + if (IS_ERR(shm))
> > > + return -EINVAL;
> > > +
> > > + data.id = shm->id;
> > > + data.flags = shm->flags;
> > > + data.size = 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 param_from_user_memref(struct tee_context *ctx,
> > > + struct tee_param_memref *memref,
> > > + struct tee_ioctl_param *ip)
> > > +{
> > > + struct tee_shm *shm;
> > > + size_t offs = 0;
> > > +
> > > + /*
> > > + * If a NULL pointer is passed to a TA in the TEE,
> > > + * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> > > + * indicating a NULL memory reference.
> > > + */
> > > + if (ip->c != TEE_MEMREF_NULL) {
> > > + /*
> > > + * If we fail to get a pointer to a shared
> > > + * memory object (and increase the ref count)
> > > + * from an identifier we return an error. All
> > > + * pointers that has been added in params have
> > > + * an increased ref count. It's the callers
> > > + * responibility to do tee_shm_put() on all
> > > + * resolved pointers.
> > > + */
> > > + shm = tee_shm_get_from_id(ctx, ip->c);
> > > + if (IS_ERR(shm))
> > > + return PTR_ERR(shm);
> > > +
> > > + /*
> > > + * Ensure offset + size does not overflow
> > > + * offset and does not overflow the size of
> > > + * the referred shared memory object.
> > > + */
> > > + if ((ip->a + ip->b) < ip->a ||
> > > + (ip->a + ip->b) > shm->size) {
> > > + tee_shm_put(shm);
> > > + return -EINVAL;
> > > + }
> > > +
> > > + if (shm->flags & TEE_SHM_DMA_BUF) {
This check is already done within tee_shm_get_parent_shm(), is it
redundant here?
> > > + struct tee_shm *parent_shm;
> > > +
> > > + parent_shm = tee_shm_get_parent_shm(shm, &offs);
> > > + if (parent_shm) {
> > > + tee_shm_put(shm);
> > > + shm = parent_shm;
> > > + }
> > > + }
> > > + } else if (ctx->cap_memref_null) {
> > > + /* Pass NULL pointer to OP-TEE */
> > > + shm = NULL;
> > > + } else {
> > > + return -EINVAL;
> > > + }
> > > +
> > > + memref->shm_offs = ip->a + offs;
> > > + memref->size = ip->b;
> > > + memref->shm = shm;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > > size_t num_params,
> > > struct tee_ioctl_param __user *uparams)
> > > @@ -360,8 +457,8 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > > size_t n;
> > >
> > > for (n = 0; n < num_params; n++) {
> > > - struct tee_shm *shm;
> > > struct tee_ioctl_param ip;
> > > + int rc;
> > >
> > > if (copy_from_user(&ip, uparams + n, sizeof(ip)))
> > > return -EFAULT;
> > > @@ -384,45 +481,10 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
> > > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
> > > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
> > > - /*
> > > - * If a NULL pointer is passed to a TA in the TEE,
> > > - * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> > > - * indicating a NULL memory reference.
> > > - */
> > > - if (ip.c != TEE_MEMREF_NULL) {
> > > - /*
> > > - * If we fail to get a pointer to a shared
> > > - * memory object (and increase the ref count)
> > > - * from an identifier we return an error. All
> > > - * pointers that has been added in params have
> > > - * an increased ref count. It's the callers
> > > - * responibility to do tee_shm_put() on all
> > > - * resolved pointers.
> > > - */
> > > - shm = tee_shm_get_from_id(ctx, ip.c);
> > > - if (IS_ERR(shm))
> > > - return PTR_ERR(shm);
> > > -
> > > - /*
> > > - * Ensure offset + size does not overflow
> > > - * offset and does not overflow the size of
> > > - * the referred shared memory object.
> > > - */
> > > - if ((ip.a + ip.b) < ip.a ||
> > > - (ip.a + ip.b) > shm->size) {
> > > - tee_shm_put(shm);
> > > - return -EINVAL;
> > > - }
> > > - } else if (ctx->cap_memref_null) {
> > > - /* Pass NULL pointer to OP-TEE */
> > > - shm = NULL;
> > > - } else {
> > > - return -EINVAL;
> > > - }
> > > -
> > > - params[n].u.memref.shm_offs = ip.a;
> > > - params[n].u.memref.size = ip.b;
> > > - params[n].u.memref.shm = shm;
> > > + rc = param_from_user_memref(ctx, ¶ms[n].u.memref,
> > > + &ip);
> > > + if (rc)
> > > + return rc;
This looks more of a refactoring, can we split it as a separate commit?
> > > break;
> > > default:
> > > /* Unknown attribute */
> > > @@ -827,6 +889,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> > > return tee_ioctl_shm_alloc(ctx, uarg);
> > > case TEE_IOC_SHM_REGISTER:
> > > return tee_ioctl_shm_register(ctx, uarg);
> > > + case TEE_IOC_SHM_REGISTER_FD:
> > > + return tee_ioctl_shm_register_fd(ctx, uarg);
> > > case TEE_IOC_OPEN_SESSION:
> > > return tee_ioctl_open_session(ctx, uarg);
> > > case TEE_IOC_INVOKE:
> > > @@ -1288,3 +1352,4 @@ MODULE_AUTHOR("Linaro");
> > > MODULE_DESCRIPTION("TEE Driver");
> > > MODULE_VERSION("1.0");
> > > MODULE_LICENSE("GPL v2");
> > > +MODULE_IMPORT_NS("DMA_BUF");
> > > diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
> > > index 6c6ff5d5eed2..aad7f6c7e0f0 100644
> > > --- a/drivers/tee/tee_private.h
> > > +++ b/drivers/tee/tee_private.h
> > > @@ -24,6 +24,7 @@ void teedev_ctx_put(struct tee_context *ctx);
> > > struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
> > > struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> > > unsigned long addr, size_t length);
> > > +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs);
> > >
> > > int tee_heap_update_from_dma_buf(struct tee_device *teedev,
> > > struct dma_buf *dmabuf, size_t *offset,
> > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> > > index daf6e5cfd59a..8b79918468b5 100644
> > > --- a/drivers/tee/tee_shm.c
> > > +++ b/drivers/tee/tee_shm.c
> > > @@ -4,6 +4,7 @@
> > > */
> > > #include <linux/anon_inodes.h>
> > > #include <linux/device.h>
> > > +#include <linux/dma-buf.h>
> > > #include <linux/idr.h>
> > > #include <linux/io.h>
> > > #include <linux/mm.h>
> > > @@ -15,6 +16,16 @@
> > > #include <linux/highmem.h>
> > > #include "tee_private.h"
> > >
> > > +/* extra references appended to shm object for registered shared memory */
> > > +struct tee_shm_dmabuf_ref {
> > > + struct tee_shm shm;
> > > + size_t offset;
> > > + struct dma_buf *dmabuf;
> > > + struct dma_buf_attachment *attach;
> > > + struct sg_table *sgt;
> > > + struct tee_shm *parent_shm;
> > > +};
> > > +
> > > static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> > > {
> > > size_t n;
> > > @@ -45,7 +56,23 @@ static void release_registered_pages(struct tee_shm *shm)
> > >
> > > static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> > > {
> > > - if (shm->flags & TEE_SHM_POOL) {
> > > + struct tee_shm *parent_shm = NULL;
> > > + void *p = shm;
> > > +
> > > + if (shm->flags & TEE_SHM_DMA_BUF) {
> > > + struct tee_shm_dmabuf_ref *ref;
> > > +
> > > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> > > + parent_shm = ref->parent_shm;
> > > + p = ref;
> > > + if (ref->attach) {
> > > + dma_buf_unmap_attachment(ref->attach, ref->sgt,
> > > + DMA_BIDIRECTIONAL);
> > > +
> > > + dma_buf_detach(ref->dmabuf, ref->attach);
> > > + }
> > > + dma_buf_put(ref->dmabuf);
> > > + } else if (shm->flags & TEE_SHM_POOL) {
> > > teedev->pool->ops->free(teedev->pool, shm);
> > > } else if (shm->flags & TEE_SHM_DYNAMIC) {
> > > int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
> > > @@ -57,9 +84,10 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> > > release_registered_pages(shm);
> > > }
> > >
> > > - teedev_ctx_put(shm->ctx);
> > > + if (shm->ctx)
> > > + teedev_ctx_put(shm->ctx);
> > >
> > > - kfree(shm);
> > > + kfree(p);
> > >
> > > tee_device_put(teedev);
> > > }
> > > @@ -169,7 +197,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
> > > * tee_client_invoke_func(). The memory allocated is later freed with a
> > > * call to tee_shm_free().
> > > *
> > > - * @returns a pointer to 'struct tee_shm'
> > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> > > */
> > > struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> > > {
> > > @@ -179,6 +207,116 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> > > }
> > > EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
> > >
> > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd)
> > > +{
> > > + struct tee_shm_dmabuf_ref *ref;
> > > + int rc;
> > > +
> > > + if (!tee_device_get(ctx->teedev))
> > > + return ERR_PTR(-EINVAL);
> > > +
> > > + teedev_ctx_get(ctx);
> > > +
> > > + ref = kzalloc(sizeof(*ref), GFP_KERNEL);
> > > + if (!ref) {
> > > + rc = -ENOMEM;
> > > + goto err_put_tee;
> > > + }
> > > +
> > > + refcount_set(&ref->shm.refcount, 1);
> > > + ref->shm.ctx = ctx;
> > > + ref->shm.id = -1;
> > > + ref->shm.flags = TEE_SHM_DMA_BUF;
> > > +
> > > + ref->dmabuf = dma_buf_get(fd);
> > > + if (IS_ERR(ref->dmabuf)) {
> > > + rc = PTR_ERR(ref->dmabuf);
> > > + goto err_kfree_ref;
> > > + }
> > > +
> > > + rc = tee_heap_update_from_dma_buf(ctx->teedev, ref->dmabuf,
> > > + &ref->offset, &ref->shm,
> > > + &ref->parent_shm);
> > > + if (!rc)
> > > + goto out;
> > > + if (rc != -EINVAL)
> > > + goto err_put_dmabuf;
> > > +
> > > + ref->attach = dma_buf_attach(ref->dmabuf, &ctx->teedev->dev);
> > > + if (IS_ERR(ref->attach)) {
> > > + rc = PTR_ERR(ref->attach);
> > > + goto err_put_dmabuf;
> > > + }
> > > +
> > > + ref->sgt = dma_buf_map_attachment(ref->attach, DMA_BIDIRECTIONAL);
> > > + if (IS_ERR(ref->sgt)) {
> > > + rc = PTR_ERR(ref->sgt);
> > > + goto err_detach;
> > > + }
> > > +
> > > + if (sg_nents(ref->sgt->sgl) != 1) {
> > > + rc = PTR_ERR(ref->sgt->sgl);
> > > + goto err_unmap_attachement;
> > > + }
> > > +
> > > + ref->shm.paddr = page_to_phys(sg_page(ref->sgt->sgl));
> > > + ref->shm.size = ref->sgt->sgl->length;
> > > +
> > > +out:
> > > + mutex_lock(&ref->shm.ctx->teedev->mutex);
> > > + ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm,
> > > + 1, 0, GFP_KERNEL);
> > > + mutex_unlock(&ref->shm.ctx->teedev->mutex);
> > > + if (ref->shm.id < 0) {
> > > + rc = ref->shm.id;
> > > + if (ref->attach)
> > > + goto err_unmap_attachement;
> > > + goto err_put_dmabuf;
> > > + }
> > > +
> > > + return &ref->shm;
> > > +
> > > +err_unmap_attachement:
> > > + dma_buf_unmap_attachment(ref->attach, ref->sgt, DMA_BIDIRECTIONAL);
> > > +err_detach:
> > > + dma_buf_detach(ref->dmabuf, ref->attach);
> > > +err_put_dmabuf:
> > > + dma_buf_put(ref->dmabuf);
> > > +err_kfree_ref:
> > > + kfree(ref);
> > > +err_put_tee:
> > > + teedev_ctx_put(ctx);
> > > + tee_device_put(ctx->teedev);
> > > +
> > > + return ERR_PTR(rc);
> > > +}
> > > +EXPORT_SYMBOL_GPL(tee_shm_register_fd);
> > > +
> > > +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs)
> > > +{
> > > + struct tee_shm *parent_shm = NULL;
> > > +
> > > + if (shm->flags & TEE_SHM_DMA_BUF) {
> > > + struct tee_shm_dmabuf_ref *ref;
> > > +
> > > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> > > + if (ref->parent_shm) {
> > > + /*
> > > + * the shm already has one reference to
> > > + * ref->parent_shm so we should be clear of 0.
> > > + * We're getting another reference since the caller
> > > + * of this function expects to put the returned
> > > + * parent_shm when it's done with it.
This seems a bit complicated, can we rather inline this API as I can't
see any other current user?
-Sumit
> > > + */
> > > + parent_shm = ref->parent_shm;
> > > + refcount_inc(&parent_shm->refcount);
> > > + *offs = ref->offset;
> > > + }
> > > + }
> > > +
> > > + return parent_shm;
> > > +}
> > > +
> > > /**
> > > * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
> > > * kernel buffer
> > > diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
> > > index 16ef078247ae..6bd833b6d0e1 100644
> > > --- a/include/linux/tee_core.h
> > > +++ b/include/linux/tee_core.h
> > > @@ -28,6 +28,7 @@
> > > #define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user space */
> > > #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */
> > > #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */
> > > +#define TEE_SHM_DMA_BUF BIT(4) /* Memory with dma-buf handle */
> > >
> > > #define TEE_DEVICE_FLAG_REGISTERED 0x1
> > > #define TEE_MAX_DEV_NAME_LEN 32
> > > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> > > index a54c203000ed..824f1251de60 100644
> > > --- a/include/linux/tee_drv.h
> > > +++ b/include/linux/tee_drv.h
> > > @@ -116,6 +116,16 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
> > > struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> > > void *addr, size_t length);
> > >
> > > +/**
> > > + * tee_shm_register_fd() - Register shared memory from file descriptor
> > > + *
> > > + * @ctx: Context that allocates the shared memory
> > > + * @fd: Shared memory file descriptor reference
> > > + *
> > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> > > + */
> > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd);
> > > +
> > > /**
> > > * tee_shm_free() - Free shared memory
> > > * @shm: Handle to shared memory to free
> > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
> > > index d0430bee8292..1f9a4ac2b211 100644
> > > --- a/include/uapi/linux/tee.h
> > > +++ b/include/uapi/linux/tee.h
> > > @@ -118,6 +118,35 @@ struct tee_ioctl_shm_alloc_data {
> > > #define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, \
> > > struct tee_ioctl_shm_alloc_data)
> > >
> > > +/**
> > > + * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument
> > > + * @fd: [in] File descriptor identifying the shared memory
> > > + * @size: [out] Size of shared memory to allocate
> > > + * @flags: [in] Flags to/from allocation.
> > > + * @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_FD below.
> > > + */
> > > +struct tee_ioctl_shm_register_fd_data {
> > > + __s64 fd;
> > > + __u64 size;
> > > + __u32 flags;
> > > + __s32 id;
> > > +};
> > > +
> > > +/**
> > > + * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file descriptor
> > > + *
> > > + * Returns a file descriptor on success or < 0 on failure
> > > + *
> > > + * The returned file descriptor refers to the shared memory object in kernel
> > > + * land. The shared memory is freed when the descriptor is closed.
> > > + */
> > > +#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 8, \
> > > + struct tee_ioctl_shm_register_fd_data)
> > > +
> > > /**
> > > * struct tee_ioctl_buf_data - Variable sized buffer
> > > * @buf_ptr: [in] A __user pointer to a buffer
> > > --
> > > 2.43.0
> > >
On Tue, Apr 1, 2025 at 10:46 AM Sumit Garg <sumit.garg@kernel.org> wrote:
>
> On Tue, Mar 25, 2025 at 12:17:20PM +0100, Jens Wiklander wrote:
> > Hi Sumit,
> >
> > On Tue, Mar 25, 2025 at 7:50 AM Sumit Garg <sumit.garg@kernel.org> wrote:
> > >
> > > Hi Jens,
> > >
> > > On Wed, Mar 05, 2025 at 02:04:12PM +0100, Jens Wiklander wrote:
> > > > From: Etienne Carriere <etienne.carriere@linaro.org>
> > > >
> > > > Enable userspace to create a tee_shm object that refers to a dmabuf
> > > > reference.
> > > >
> > > > Userspace registers the dmabuf file descriptor as in a tee_shm object.
> > > > The registration is completed with a tee_shm file descriptor returned to
> > > > userspace.
> > > >
> > > > Userspace is free to close the dmabuf file descriptor now since all the
> > > > resources are now held via the tee_shm object.
> > > >
> > > > Closing the tee_shm file descriptor will release all resources used by the
> > > > tee_shm object.
> > > >
> > > > This change only support dmabuf references that relates to physically
> > > > contiguous memory buffers.
>
> Let's try to reframe this commit message to say that new ioctl allows to
> register DMA buffers allocated from restricted/protected heaps with TEE
> subsystem.
>
> > > >
> > > > New tee_shm flag to identify tee_shm objects built from a registered
> > > > dmabuf, TEE_SHM_DMA_BUF.
> > > >
> > > > Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
> > > > Signed-off-by: Olivier Masse <olivier.masse@nxp.com>
> > > > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > > > ---
> > > > drivers/tee/tee_core.c | 145 ++++++++++++++++++++++++++-----------
> > > > drivers/tee/tee_private.h | 1 +
> > > > drivers/tee/tee_shm.c | 146 ++++++++++++++++++++++++++++++++++++--
> > > > include/linux/tee_core.h | 1 +
> > > > include/linux/tee_drv.h | 10 +++
> > > > include/uapi/linux/tee.h | 29 ++++++++
> > > > 6 files changed, 288 insertions(+), 44 deletions(-)
> > > >
> > >
> > > I am still trying to find if we really need a separate IOCTL to register
> > > DMA heap with TEE subsystem. Can't we initialize tee_shm as a member of
> > > struct tee_heap_buffer in tee_dma_heap_alloc() where the allocation
> > > happens?
> >
> > No, that's not possible since we don't have a tee_context availble so
> > we can't assign an ID that userspace can use for this shm object.
> >
> > We could add new attribute types TEE_IOCTL_PARAM_ATTR_TYPE_MEMFD_*,
> > but it's a bit more complicated than that since we'd also need to
> > update for the life cycle.
>
> Okay, that's fair enough. Lets take this new IOCTL approach then.
>
> >
> >
> > > We can always find a reference back to tee_shm object from DMA
> > > buffer.
> >
> > Yes
> >
> > Cheers,
> > Jens
> >
> > >
> > > -Sumit
> > >
> > > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> > > > index 685afcaa3ea1..3a71643766d5 100644
> > > > --- a/drivers/tee/tee_core.c
> > > > +++ b/drivers/tee/tee_core.c
> > > > @@ -353,6 +353,103 @@ tee_ioctl_shm_register(struct tee_context *ctx,
> > > > return ret;
> > > > }
> > > >
> > > > +static int
> > > > +tee_ioctl_shm_register_fd(struct tee_context *ctx,
> > > > + struct tee_ioctl_shm_register_fd_data __user *udata)
> > > > +{
> > > > + struct tee_ioctl_shm_register_fd_data data;
> > > > + struct tee_shm *shm;
> > > > + long ret;
> > > > +
> > > > + 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_fd(ctx, data.fd);
> > > > + if (IS_ERR(shm))
> > > > + return -EINVAL;
> > > > +
> > > > + data.id = shm->id;
> > > > + data.flags = shm->flags;
> > > > + data.size = 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 param_from_user_memref(struct tee_context *ctx,
> > > > + struct tee_param_memref *memref,
> > > > + struct tee_ioctl_param *ip)
> > > > +{
> > > > + struct tee_shm *shm;
> > > > + size_t offs = 0;
> > > > +
> > > > + /*
> > > > + * If a NULL pointer is passed to a TA in the TEE,
> > > > + * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> > > > + * indicating a NULL memory reference.
> > > > + */
> > > > + if (ip->c != TEE_MEMREF_NULL) {
> > > > + /*
> > > > + * If we fail to get a pointer to a shared
> > > > + * memory object (and increase the ref count)
> > > > + * from an identifier we return an error. All
> > > > + * pointers that has been added in params have
> > > > + * an increased ref count. It's the callers
> > > > + * responibility to do tee_shm_put() on all
> > > > + * resolved pointers.
> > > > + */
> > > > + shm = tee_shm_get_from_id(ctx, ip->c);
> > > > + if (IS_ERR(shm))
> > > > + return PTR_ERR(shm);
> > > > +
> > > > + /*
> > > > + * Ensure offset + size does not overflow
> > > > + * offset and does not overflow the size of
> > > > + * the referred shared memory object.
> > > > + */
> > > > + if ((ip->a + ip->b) < ip->a ||
> > > > + (ip->a + ip->b) > shm->size) {
> > > > + tee_shm_put(shm);
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + if (shm->flags & TEE_SHM_DMA_BUF) {
>
> This check is already done within tee_shm_get_parent_shm(), is it
> redundant here?
Yes, I'll remove it.
>
> > > > + struct tee_shm *parent_shm;
> > > > +
> > > > + parent_shm = tee_shm_get_parent_shm(shm, &offs);
> > > > + if (parent_shm) {
> > > > + tee_shm_put(shm);
> > > > + shm = parent_shm;
> > > > + }
> > > > + }
> > > > + } else if (ctx->cap_memref_null) {
> > > > + /* Pass NULL pointer to OP-TEE */
> > > > + shm = NULL;
> > > > + } else {
> > > > + return -EINVAL;
> > > > + }
> > > > +
> > > > + memref->shm_offs = ip->a + offs;
> > > > + memref->size = ip->b;
> > > > + memref->shm = shm;
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > > > size_t num_params,
> > > > struct tee_ioctl_param __user *uparams)
> > > > @@ -360,8 +457,8 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > > > size_t n;
> > > >
> > > > for (n = 0; n < num_params; n++) {
> > > > - struct tee_shm *shm;
> > > > struct tee_ioctl_param ip;
> > > > + int rc;
> > > >
> > > > if (copy_from_user(&ip, uparams + n, sizeof(ip)))
> > > > return -EFAULT;
> > > > @@ -384,45 +481,10 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params,
> > > > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
> > > > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
> > > > case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
> > > > - /*
> > > > - * If a NULL pointer is passed to a TA in the TEE,
> > > > - * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
> > > > - * indicating a NULL memory reference.
> > > > - */
> > > > - if (ip.c != TEE_MEMREF_NULL) {
> > > > - /*
> > > > - * If we fail to get a pointer to a shared
> > > > - * memory object (and increase the ref count)
> > > > - * from an identifier we return an error. All
> > > > - * pointers that has been added in params have
> > > > - * an increased ref count. It's the callers
> > > > - * responibility to do tee_shm_put() on all
> > > > - * resolved pointers.
> > > > - */
> > > > - shm = tee_shm_get_from_id(ctx, ip.c);
> > > > - if (IS_ERR(shm))
> > > > - return PTR_ERR(shm);
> > > > -
> > > > - /*
> > > > - * Ensure offset + size does not overflow
> > > > - * offset and does not overflow the size of
> > > > - * the referred shared memory object.
> > > > - */
> > > > - if ((ip.a + ip.b) < ip.a ||
> > > > - (ip.a + ip.b) > shm->size) {
> > > > - tee_shm_put(shm);
> > > > - return -EINVAL;
> > > > - }
> > > > - } else if (ctx->cap_memref_null) {
> > > > - /* Pass NULL pointer to OP-TEE */
> > > > - shm = NULL;
> > > > - } else {
> > > > - return -EINVAL;
> > > > - }
> > > > -
> > > > - params[n].u.memref.shm_offs = ip.a;
> > > > - params[n].u.memref.size = ip.b;
> > > > - params[n].u.memref.shm = shm;
> > > > + rc = param_from_user_memref(ctx, ¶ms[n].u.memref,
> > > > + &ip);
> > > > + if (rc)
> > > > + return rc;
>
> This looks more of a refactoring, can we split it as a separate commit?
Sure
>
> > > > break;
> > > > default:
> > > > /* Unknown attribute */
> > > > @@ -827,6 +889,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> > > > return tee_ioctl_shm_alloc(ctx, uarg);
> > > > case TEE_IOC_SHM_REGISTER:
> > > > return tee_ioctl_shm_register(ctx, uarg);
> > > > + case TEE_IOC_SHM_REGISTER_FD:
> > > > + return tee_ioctl_shm_register_fd(ctx, uarg);
> > > > case TEE_IOC_OPEN_SESSION:
> > > > return tee_ioctl_open_session(ctx, uarg);
> > > > case TEE_IOC_INVOKE:
> > > > @@ -1288,3 +1352,4 @@ MODULE_AUTHOR("Linaro");
> > > > MODULE_DESCRIPTION("TEE Driver");
> > > > MODULE_VERSION("1.0");
> > > > MODULE_LICENSE("GPL v2");
> > > > +MODULE_IMPORT_NS("DMA_BUF");
> > > > diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
> > > > index 6c6ff5d5eed2..aad7f6c7e0f0 100644
> > > > --- a/drivers/tee/tee_private.h
> > > > +++ b/drivers/tee/tee_private.h
> > > > @@ -24,6 +24,7 @@ void teedev_ctx_put(struct tee_context *ctx);
> > > > struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
> > > > struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> > > > unsigned long addr, size_t length);
> > > > +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs);
> > > >
> > > > int tee_heap_update_from_dma_buf(struct tee_device *teedev,
> > > > struct dma_buf *dmabuf, size_t *offset,
> > > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> > > > index daf6e5cfd59a..8b79918468b5 100644
> > > > --- a/drivers/tee/tee_shm.c
> > > > +++ b/drivers/tee/tee_shm.c
> > > > @@ -4,6 +4,7 @@
> > > > */
> > > > #include <linux/anon_inodes.h>
> > > > #include <linux/device.h>
> > > > +#include <linux/dma-buf.h>
> > > > #include <linux/idr.h>
> > > > #include <linux/io.h>
> > > > #include <linux/mm.h>
> > > > @@ -15,6 +16,16 @@
> > > > #include <linux/highmem.h>
> > > > #include "tee_private.h"
> > > >
> > > > +/* extra references appended to shm object for registered shared memory */
> > > > +struct tee_shm_dmabuf_ref {
> > > > + struct tee_shm shm;
> > > > + size_t offset;
> > > > + struct dma_buf *dmabuf;
> > > > + struct dma_buf_attachment *attach;
> > > > + struct sg_table *sgt;
> > > > + struct tee_shm *parent_shm;
> > > > +};
> > > > +
> > > > static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> > > > {
> > > > size_t n;
> > > > @@ -45,7 +56,23 @@ static void release_registered_pages(struct tee_shm *shm)
> > > >
> > > > static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> > > > {
> > > > - if (shm->flags & TEE_SHM_POOL) {
> > > > + struct tee_shm *parent_shm = NULL;
> > > > + void *p = shm;
> > > > +
> > > > + if (shm->flags & TEE_SHM_DMA_BUF) {
> > > > + struct tee_shm_dmabuf_ref *ref;
> > > > +
> > > > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> > > > + parent_shm = ref->parent_shm;
> > > > + p = ref;
> > > > + if (ref->attach) {
> > > > + dma_buf_unmap_attachment(ref->attach, ref->sgt,
> > > > + DMA_BIDIRECTIONAL);
> > > > +
> > > > + dma_buf_detach(ref->dmabuf, ref->attach);
> > > > + }
> > > > + dma_buf_put(ref->dmabuf);
> > > > + } else if (shm->flags & TEE_SHM_POOL) {
> > > > teedev->pool->ops->free(teedev->pool, shm);
> > > > } else if (shm->flags & TEE_SHM_DYNAMIC) {
> > > > int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
> > > > @@ -57,9 +84,10 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
> > > > release_registered_pages(shm);
> > > > }
> > > >
> > > > - teedev_ctx_put(shm->ctx);
> > > > + if (shm->ctx)
> > > > + teedev_ctx_put(shm->ctx);
> > > >
> > > > - kfree(shm);
> > > > + kfree(p);
> > > >
> > > > tee_device_put(teedev);
> > > > }
> > > > @@ -169,7 +197,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
> > > > * tee_client_invoke_func(). The memory allocated is later freed with a
> > > > * call to tee_shm_free().
> > > > *
> > > > - * @returns a pointer to 'struct tee_shm'
> > > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> > > > */
> > > > struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> > > > {
> > > > @@ -179,6 +207,116 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
> > > > }
> > > > EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
> > > >
> > > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd)
> > > > +{
> > > > + struct tee_shm_dmabuf_ref *ref;
> > > > + int rc;
> > > > +
> > > > + if (!tee_device_get(ctx->teedev))
> > > > + return ERR_PTR(-EINVAL);
> > > > +
> > > > + teedev_ctx_get(ctx);
> > > > +
> > > > + ref = kzalloc(sizeof(*ref), GFP_KERNEL);
> > > > + if (!ref) {
> > > > + rc = -ENOMEM;
> > > > + goto err_put_tee;
> > > > + }
> > > > +
> > > > + refcount_set(&ref->shm.refcount, 1);
> > > > + ref->shm.ctx = ctx;
> > > > + ref->shm.id = -1;
> > > > + ref->shm.flags = TEE_SHM_DMA_BUF;
> > > > +
> > > > + ref->dmabuf = dma_buf_get(fd);
> > > > + if (IS_ERR(ref->dmabuf)) {
> > > > + rc = PTR_ERR(ref->dmabuf);
> > > > + goto err_kfree_ref;
> > > > + }
> > > > +
> > > > + rc = tee_heap_update_from_dma_buf(ctx->teedev, ref->dmabuf,
> > > > + &ref->offset, &ref->shm,
> > > > + &ref->parent_shm);
> > > > + if (!rc)
> > > > + goto out;
> > > > + if (rc != -EINVAL)
> > > > + goto err_put_dmabuf;
> > > > +
> > > > + ref->attach = dma_buf_attach(ref->dmabuf, &ctx->teedev->dev);
> > > > + if (IS_ERR(ref->attach)) {
> > > > + rc = PTR_ERR(ref->attach);
> > > > + goto err_put_dmabuf;
> > > > + }
> > > > +
> > > > + ref->sgt = dma_buf_map_attachment(ref->attach, DMA_BIDIRECTIONAL);
> > > > + if (IS_ERR(ref->sgt)) {
> > > > + rc = PTR_ERR(ref->sgt);
> > > > + goto err_detach;
> > > > + }
> > > > +
> > > > + if (sg_nents(ref->sgt->sgl) != 1) {
> > > > + rc = PTR_ERR(ref->sgt->sgl);
> > > > + goto err_unmap_attachement;
> > > > + }
> > > > +
> > > > + ref->shm.paddr = page_to_phys(sg_page(ref->sgt->sgl));
> > > > + ref->shm.size = ref->sgt->sgl->length;
> > > > +
> > > > +out:
> > > > + mutex_lock(&ref->shm.ctx->teedev->mutex);
> > > > + ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm,
> > > > + 1, 0, GFP_KERNEL);
> > > > + mutex_unlock(&ref->shm.ctx->teedev->mutex);
> > > > + if (ref->shm.id < 0) {
> > > > + rc = ref->shm.id;
> > > > + if (ref->attach)
> > > > + goto err_unmap_attachement;
> > > > + goto err_put_dmabuf;
> > > > + }
> > > > +
> > > > + return &ref->shm;
> > > > +
> > > > +err_unmap_attachement:
> > > > + dma_buf_unmap_attachment(ref->attach, ref->sgt, DMA_BIDIRECTIONAL);
> > > > +err_detach:
> > > > + dma_buf_detach(ref->dmabuf, ref->attach);
> > > > +err_put_dmabuf:
> > > > + dma_buf_put(ref->dmabuf);
> > > > +err_kfree_ref:
> > > > + kfree(ref);
> > > > +err_put_tee:
> > > > + teedev_ctx_put(ctx);
> > > > + tee_device_put(ctx->teedev);
> > > > +
> > > > + return ERR_PTR(rc);
> > > > +}
> > > > +EXPORT_SYMBOL_GPL(tee_shm_register_fd);
> > > > +
> > > > +struct tee_shm *tee_shm_get_parent_shm(struct tee_shm *shm, size_t *offs)
> > > > +{
> > > > + struct tee_shm *parent_shm = NULL;
> > > > +
> > > > + if (shm->flags & TEE_SHM_DMA_BUF) {
> > > > + struct tee_shm_dmabuf_ref *ref;
> > > > +
> > > > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
> > > > + if (ref->parent_shm) {
> > > > + /*
> > > > + * the shm already has one reference to
> > > > + * ref->parent_shm so we should be clear of 0.
> > > > + * We're getting another reference since the caller
> > > > + * of this function expects to put the returned
> > > > + * parent_shm when it's done with it.
>
> This seems a bit complicated, can we rather inline this API as I can't
> see any other current user?
OK
Cheers,
Jens
>
> -Sumit
>
> > > > + */
> > > > + parent_shm = ref->parent_shm;
> > > > + refcount_inc(&parent_shm->refcount);
> > > > + *offs = ref->offset;
> > > > + }
> > > > + }
> > > > +
> > > > + return parent_shm;
> > > > +}
> > > > +
> > > > /**
> > > > * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
> > > > * kernel buffer
> > > > diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
> > > > index 16ef078247ae..6bd833b6d0e1 100644
> > > > --- a/include/linux/tee_core.h
> > > > +++ b/include/linux/tee_core.h
> > > > @@ -28,6 +28,7 @@
> > > > #define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user space */
> > > > #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */
> > > > #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */
> > > > +#define TEE_SHM_DMA_BUF BIT(4) /* Memory with dma-buf handle */
> > > >
> > > > #define TEE_DEVICE_FLAG_REGISTERED 0x1
> > > > #define TEE_MAX_DEV_NAME_LEN 32
> > > > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> > > > index a54c203000ed..824f1251de60 100644
> > > > --- a/include/linux/tee_drv.h
> > > > +++ b/include/linux/tee_drv.h
> > > > @@ -116,6 +116,16 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
> > > > struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> > > > void *addr, size_t length);
> > > >
> > > > +/**
> > > > + * tee_shm_register_fd() - Register shared memory from file descriptor
> > > > + *
> > > > + * @ctx: Context that allocates the shared memory
> > > > + * @fd: Shared memory file descriptor reference
> > > > + *
> > > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
> > > > + */
> > > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd);
> > > > +
> > > > /**
> > > > * tee_shm_free() - Free shared memory
> > > > * @shm: Handle to shared memory to free
> > > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
> > > > index d0430bee8292..1f9a4ac2b211 100644
> > > > --- a/include/uapi/linux/tee.h
> > > > +++ b/include/uapi/linux/tee.h
> > > > @@ -118,6 +118,35 @@ struct tee_ioctl_shm_alloc_data {
> > > > #define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, \
> > > > struct tee_ioctl_shm_alloc_data)
> > > >
> > > > +/**
> > > > + * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument
> > > > + * @fd: [in] File descriptor identifying the shared memory
> > > > + * @size: [out] Size of shared memory to allocate
> > > > + * @flags: [in] Flags to/from allocation.
> > > > + * @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_FD below.
> > > > + */
> > > > +struct tee_ioctl_shm_register_fd_data {
> > > > + __s64 fd;
> > > > + __u64 size;
> > > > + __u32 flags;
> > > > + __s32 id;
> > > > +};
> > > > +
> > > > +/**
> > > > + * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file descriptor
> > > > + *
> > > > + * Returns a file descriptor on success or < 0 on failure
> > > > + *
> > > > + * The returned file descriptor refers to the shared memory object in kernel
> > > > + * land. The shared memory is freed when the descriptor is closed.
> > > > + */
> > > > +#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 8, \
> > > > + struct tee_ioctl_shm_register_fd_data)
> > > > +
> > > > /**
> > > > * struct tee_ioctl_buf_data - Variable sized buffer
> > > > * @buf_ptr: [in] A __user pointer to a buffer
> > > > --
> > > > 2.43.0
> > > >
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