[PATCH 1/1] tee: new ioctl to a register tee_shm from a dmabuf file descriptor
Olivier Masse
olivier.masse at nxp.com
Thu Aug 11 13:56:37 UTC 2022
From: Etienne Carriere <etienne.carriere at linaro.org>
This change allows userland to create a tee_shm object that refers
to a dmabuf reference.
Userland provides a dmabuf file descriptor as buffer reference.
The created tee_shm object exported as a brand new dmabuf reference
used to provide a clean fd to userland. Userland shall closed this new
fd to release the tee_shm object resources. The initial dmabuf resources
are tracked independently through original dmabuf file descriptor.
Once the buffer is registered and until it is released, TEE driver
keeps a refcount on the registered dmabuf structure.
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_EXT_DMA_BUF. Such tee_shm structures are flagged with
TEE_SHM_EXT_DMA_BUF.
Co-Developed-by: Etienne Carriere <etienne.carriere at linaro.org>
Signed-off-by: Olivier Masse <olivier.masse at nxp.com>
From: https://github.com/linaro-swg/linux.git
(cherry picked from commit 41e21e5c405530590dc2dd10b2a8dbe64589840f)
---
drivers/tee/tee_core.c | 38 +++++++++++++++
drivers/tee/tee_shm.c | 99 +++++++++++++++++++++++++++++++++++++++-
include/linux/tee_drv.h | 11 +++++
include/uapi/linux/tee.h | 29 ++++++++++++
4 files changed, 175 insertions(+), 2 deletions(-)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 8aa1a4836b92..7c45cbf85eb9 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -355,6 +355,42 @@ 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 params_from_user(struct tee_context *ctx, struct tee_param *params,
size_t num_params,
struct tee_ioctl_param __user *uparams)
@@ -829,6 +865,8 @@ 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:
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 836872467dc6..55a3fbbb022e 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/mm.h>
#include <linux/sched.h>
@@ -12,6 +13,14 @@
#include <linux/uio.h>
#include "tee_private.h"
+/* extra references appended to shm object for registered shared memory */
+struct tee_shm_dmabuf_ref {
+ struct tee_shm shm;
+ struct dma_buf *dmabuf;
+ struct dma_buf_attachment *attach;
+ struct sg_table *sgt;
+};
+
static void shm_put_kernel_pages(struct page **pages, size_t page_count)
{
size_t n;
@@ -71,7 +80,16 @@ 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) {
+ if (shm->flags & TEE_SHM_EXT_DMA_BUF) {
+ struct tee_shm_dmabuf_ref *ref;
+
+ ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
+ 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);
@@ -195,7 +213,7 @@ 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)
{
@@ -229,6 +247,83 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
}
EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_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->dmabuf = dma_buf_get(fd);
+ if (IS_ERR(ref->dmabuf)) {
+ rc = PTR_ERR(ref->dmabuf);
+ goto err_put_dmabuf;
+ }
+
+ ref->attach = dma_buf_attach(ref->dmabuf, &ref->shm.ctx->teedev->dev);
+ if (IS_ERR(ref->attach)) {
+ rc = PTR_ERR(ref->attach);
+ goto err_detach;
+ }
+
+ ref->sgt = dma_buf_map_attachment(ref->attach, DMA_BIDIRECTIONAL);
+ if (IS_ERR(ref->sgt)) {
+ rc = PTR_ERR(ref->sgt);
+ goto err_unmap_attachement;
+ }
+
+ if (sg_nents(ref->sgt->sgl) != 1) {
+ rc = PTR_ERR(ref->sgt->sgl);
+ goto err_unmap_attachement;
+ }
+
+ ref->shm.paddr = sg_dma_address(ref->sgt->sgl);
+ ref->shm.size = sg_dma_len(ref->sgt->sgl);
+ ref->shm.flags = TEE_SHM_EXT_DMA_BUF;
+
+ 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;
+ goto err_idr_remove;
+ }
+
+ return &ref->shm;
+
+err_idr_remove:
+ mutex_lock(&ctx->teedev->mutex);
+ idr_remove(&ctx->teedev->idr, ref->shm.id);
+ mutex_unlock(&ctx->teedev->mutex);
+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);
+ 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);
+
static struct tee_shm *
register_shm_helper(struct tee_context *ctx, unsigned long addr,
size_t length, u32 flags, int id)
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index 911cad324acc..40ddd5376c2d 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -25,6 +25,7 @@
#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_EXT_DMA_BUF BIT(4) /* Memory with dma-buf handle */
struct device;
struct tee_device;
@@ -276,6 +277,16 @@ 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_is_dynamic() - Check if shared memory object is of the dynamic kind
* @shm: Shared memory handle
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 25a6c534beb1..6f84060ad005 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -121,6 +121,35 @@ 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;
+} __aligned(8);
+
+/**
+ * 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
--
2.25.0
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