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Subject[PATCH v1 02/14] tee: add register user memory
Date
From: Jens Wiklander <jens.wiklander@linaro.org>

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

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
---
drivers/tee/tee_core.c | 41 ++++++++-
drivers/tee/tee_shm.c | 210 +++++++++++++++++++++++++++++++++++++++++------
include/linux/tee_drv.h | 44 +++++++++-
include/uapi/linux/tee.h | 30 +++++++
4 files changed, 295 insertions(+), 30 deletions(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 58a5009..295910f 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -114,8 +114,6 @@ static int tee_ioctl_shm_alloc(struct tee_context *ctx,
if (data.flags)
return -EINVAL;

- data.id = -1;
-
shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
if (IS_ERR(shm))
return PTR_ERR(shm);
@@ -138,6 +136,43 @@ static int tee_ioctl_shm_alloc(struct tee_context *ctx,
return ret;
}

+static int
+tee_ioctl_shm_register(struct tee_context *ctx,
+ struct tee_ioctl_shm_register_data __user *udata)
+{
+ long ret;
+ struct tee_ioctl_shm_register_data data;
+ struct tee_shm *shm;
+
+ if (copy_from_user(&data, udata, sizeof(data)))
+ return -EFAULT;
+
+ /* Currently no input flags are supported */
+ if (data.flags)
+ return -EINVAL;
+
+ shm = tee_shm_register(ctx, data.addr, data.length,
+ TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
+ if (IS_ERR(shm))
+ return PTR_ERR(shm);
+
+ data.id = shm->id;
+ data.flags = shm->flags;
+ data.length = shm->size;
+
+ if (copy_to_user(udata, &data, sizeof(data)))
+ ret = -EFAULT;
+ else
+ ret = tee_shm_get_fd(shm);
+ /*
+ * When user space closes the file descriptor the shared memory
+ * should be freed or if tee_shm_get_fd() failed then it will
+ * be freed immediately.
+ */
+ tee_shm_put(shm);
+ return ret;
+}
+
static int params_from_user(struct tee_context *ctx, struct tee_param *params,
size_t num_params,
struct tee_ioctl_param __user *uparams)
@@ -586,6 +621,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return tee_ioctl_version(ctx, uarg);
case TEE_IOC_SHM_ALLOC:
return tee_ioctl_shm_alloc(ctx, uarg);
+ case TEE_IOC_SHM_REGISTER:
+ return tee_ioctl_shm_register(ctx, uarg);
case TEE_IOC_OPEN_SESSION:
return tee_ioctl_open_session(ctx, uarg);
case TEE_IOC_INVOKE:
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index fdda89e..1ed708c 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -23,7 +23,6 @@
static void tee_shm_release(struct tee_shm *shm)
{
struct tee_device *teedev = shm->teedev;
- struct tee_shm_pool_mgr *poolm;

mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, shm->id);
@@ -31,12 +30,29 @@ static void tee_shm_release(struct tee_shm *shm)
list_del(&shm->link);
mutex_unlock(&teedev->mutex);

- if (shm->flags & TEE_SHM_DMA_BUF)
- poolm = teedev->pool->dma_buf_mgr;
- else
- poolm = teedev->pool->private_mgr;
+ if (shm->flags & TEE_SHM_POOL) {
+ struct tee_shm_pool_mgr *poolm;
+
+ if (shm->flags & TEE_SHM_DMA_BUF)
+ poolm = teedev->pool->dma_buf_mgr;
+ else
+ poolm = teedev->pool->private_mgr;
+
+ poolm->ops->free(poolm, shm);
+ } else if (shm->flags & TEE_SHM_REGISTER) {
+ size_t n;
+ int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
+
+ if (rc)
+ dev_err(teedev->dev.parent,
+ "unregister shm %p failed: %d", shm, rc);
+
+ for (n = 0; n < shm->num_pages; n++)
+ put_page(shm->pages[n]);
+
+ kfree(shm->pages);
+ }

- poolm->ops->free(poolm, shm);
kfree(shm);

tee_device_put(teedev);
@@ -76,6 +92,10 @@ static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
struct tee_shm *shm = dmabuf->priv;
size_t size = vma->vm_end - vma->vm_start;

+ /* Refuse sharing shared memory provided by application */
+ if (shm->flags & TEE_SHM_REGISTER)
+ return -EINVAL;
+
return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
size, vma->vm_page_prot);
}
@@ -89,26 +109,20 @@ static const struct dma_buf_ops tee_shm_dma_buf_ops = {
.mmap = tee_shm_op_mmap,
};

-/**
- * tee_shm_alloc() - Allocate shared memory
- * @ctx: Context that allocates the shared memory
- * @size: Requested size of shared memory
- * @flags: Flags setting properties for the requested shared memory.
- *
- * Memory allocated as global shared memory is automatically freed when the
- * TEE file pointer is closed. The @flags field uses the bits defined by
- * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
- * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
- * associated with a dma-buf handle, else driver private memory.
- */
-struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
+struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
+ struct tee_device *teedev,
+ size_t size, u32 flags)
{
- struct tee_device *teedev = ctx->teedev;
struct tee_shm_pool_mgr *poolm = NULL;
struct tee_shm *shm;
void *ret;
int rc;

+ if (ctx && ctx->teedev != teedev) {
+ dev_err(teedev->dev.parent, "ctx and teedev mismatch\n");
+ return ERR_PTR(-EINVAL);
+ }
+
if (!(flags & TEE_SHM_MAPPED)) {
dev_err(teedev->dev.parent,
"only mapped allocations supported\n");
@@ -135,7 +149,7 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
goto err_dev_put;
}

- shm->flags = flags;
+ shm->flags = flags | TEE_SHM_POOL;
shm->teedev = teedev;
shm->ctx = ctx;
if (flags & TEE_SHM_DMA_BUF)
@@ -171,9 +185,12 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
goto err_rem;
}
}
- mutex_lock(&teedev->mutex);
- list_add_tail(&shm->link, &ctx->list_shm);
- mutex_unlock(&teedev->mutex);
+
+ if (ctx) {
+ mutex_lock(&teedev->mutex);
+ list_add_tail(&shm->link, &ctx->list_shm);
+ mutex_unlock(&teedev->mutex);
+ }

return shm;
err_rem:
@@ -188,8 +205,138 @@ struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
tee_device_put(teedev);
return ret;
}
+/**
+ * tee_shm_alloc() - Allocate shared memory
+ * @ctx: Context that allocates the shared memory
+ * @size: Requested size of shared memory
+ * @flags: Flags setting properties for the requested shared memory.
+ *
+ * Memory allocated as global shared memory is automatically freed when the
+ * TEE file pointer is closed. The @flags field uses the bits defined by
+ * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
+ * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
+ * associated with a dma-buf handle, else driver private memory.
+ */
+struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
+{
+ return __tee_shm_alloc(ctx, ctx->teedev, size, flags);
+}
EXPORT_SYMBOL_GPL(tee_shm_alloc);

+struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size)
+{
+ return __tee_shm_alloc(NULL, teedev, size, TEE_SHM_MAPPED);
+}
+EXPORT_SYMBOL_GPL(tee_shm_priv_alloc);
+
+struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
+ size_t length, u32 flags)
+{
+ struct tee_device *teedev = ctx->teedev;
+ const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
+ struct tee_shm *shm;
+ void *ret;
+ int rc;
+ int num_pages;
+ unsigned long start;
+
+ if (flags != req_flags) {
+ dev_err(teedev->dev.parent, "invliad shm flags %#x", flags);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!tee_device_get(teedev))
+ return ERR_PTR(-EINVAL);
+
+ if (!teedev->desc->ops->shm_register ||
+ !teedev->desc->ops->shm_unregister) {
+ dev_err(teedev->dev.parent,
+ "register shared memory unspported by device");
+ tee_device_put(teedev);
+ return ERR_PTR(-EINVAL);
+ }
+
+ shm = kzalloc(sizeof(*shm), GFP_KERNEL);
+ if (!shm) {
+ ret = ERR_PTR(-ENOMEM);
+ goto err;
+ }
+
+ shm->flags = flags | TEE_SHM_REGISTER;
+ shm->teedev = teedev;
+ shm->ctx = ctx;
+ shm->id = -1;
+ start = rounddown(addr, PAGE_SIZE);
+ shm->offset = addr - start;
+ shm->size = length;
+ num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
+ shm->pages = kcalloc(num_pages, sizeof(struct page), GFP_KERNEL);
+ if (!shm->pages) {
+ ret = ERR_PTR(-ENOMEM);
+ goto err;
+ }
+
+ rc = get_user_pages_fast(start, num_pages, 1, shm->pages);
+ if (rc > 0)
+ shm->num_pages = rc;
+ if (rc != num_pages) {
+ if (rc > 0)
+ rc = -ENOMEM;
+ ret = ERR_PTR(rc);
+ goto err;
+ }
+
+ mutex_lock(&teedev->mutex);
+ shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
+ mutex_unlock(&teedev->mutex);
+
+ rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
+ shm->num_pages);
+ if (rc) {
+ ret = ERR_PTR(rc);
+ goto err;
+ }
+
+ if (flags & TEE_SHM_DMA_BUF) {
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &tee_shm_dma_buf_ops;
+ exp_info.size = shm->size;
+ exp_info.flags = O_RDWR;
+ exp_info.priv = shm;
+
+ shm->dmabuf = dma_buf_export(&exp_info);
+ if (IS_ERR(shm->dmabuf)) {
+ ret = ERR_CAST(shm->dmabuf);
+ teedev->desc->ops->shm_unregister(ctx, shm);
+ goto err;
+ }
+ }
+
+ mutex_lock(&teedev->mutex);
+ list_add_tail(&shm->link, &ctx->list_shm);
+ mutex_unlock(&teedev->mutex);
+
+ return shm;
+err:
+ if (shm) {
+ size_t n;
+
+ if (shm->id >= 0) {
+ mutex_lock(&teedev->mutex);
+ idr_remove(&teedev->idr, shm->id);
+ mutex_unlock(&teedev->mutex);
+ }
+ for (n = 0; n < shm->num_pages; n++)
+ put_page(shm->pages[n]);
+ kfree(shm->pages);
+ }
+ kfree(shm);
+ tee_device_put(teedev);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tee_shm_register);
+
/**
* tee_shm_get_fd() - Increase reference count and return file descriptor
* @shm: Shared memory handle
@@ -197,10 +344,9 @@ EXPORT_SYMBOL_GPL(tee_shm_alloc);
*/
int tee_shm_get_fd(struct tee_shm *shm)
{
- u32 req_flags = TEE_SHM_MAPPED | TEE_SHM_DMA_BUF;
int fd;

- if ((shm->flags & req_flags) != req_flags)
+ if (!(shm->flags & TEE_SHM_DMA_BUF))
return -EINVAL;

fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
@@ -238,6 +384,8 @@ EXPORT_SYMBOL_GPL(tee_shm_free);
*/
int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
{
+ if (!(shm->flags & TEE_SHM_MAPPED))
+ return -EINVAL;
/* Check that we're in the range of the shm */
if ((char *)va < (char *)shm->kaddr)
return -EINVAL;
@@ -258,6 +406,8 @@ EXPORT_SYMBOL_GPL(tee_shm_va2pa);
*/
int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
{
+ if (!(shm->flags & TEE_SHM_MAPPED))
+ return -EINVAL;
/* Check that we're in the range of the shm */
if (pa < shm->paddr)
return -EINVAL;
@@ -284,6 +434,8 @@ EXPORT_SYMBOL_GPL(tee_shm_pa2va);
*/
void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
{
+ if (!(shm->flags & TEE_SHM_MAPPED))
+ return ERR_PTR(-EINVAL);
if (offs >= shm->size)
return ERR_PTR(-EINVAL);
return (char *)shm->kaddr + offs;
@@ -335,6 +487,12 @@ struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
}
EXPORT_SYMBOL_GPL(tee_shm_get_from_id);

+bool tee_shm_is_registered(struct tee_shm *shm)
+{
+ return shm && (shm->flags & TEE_SHM_REGISTER);
+}
+EXPORT_SYMBOL_GPL(tee_shm_is_registered);
+
/**
* tee_shm_get_id() - Get id of a shared memory object
* @shm: Shared memory handle
diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
index e9be4a4..49d6361 100644
--- a/include/linux/tee_drv.h
+++ b/include/linux/tee_drv.h
@@ -25,8 +25,12 @@
* specific TEE driver.
*/

-#define TEE_SHM_MAPPED 0x1 /* Memory mapped by the kernel */
-#define TEE_SHM_DMA_BUF 0x2 /* Memory with dma-buf handle */
+#define TEE_SHM_MAPPED BIT(0) /* Memory mapped by the kernel */
+#define TEE_SHM_DMA_BUF BIT(1) /* Memory with dma-buf handle */
+#define TEE_SHM_EXT_DMA_BUF BIT(2) /* Memory with dma-buf handle */
+#define TEE_SHM_REGISTER BIT(3) /* Memory registered in secure world */
+#define TEE_SHM_USER_MAPPED BIT(4) /* Memory mapped in user space */
+#define TEE_SHM_POOL BIT(5) /* Memory allocated from pool */

struct device;
struct tee_device;
@@ -76,6 +80,8 @@ struct tee_param {
* @cancel_req: request cancel of an ongoing invoke or open
* @supp_revc: called for supplicant to get a command
* @supp_send: called for supplicant to send a response
+ * @shm_register: register shared memory buffer in TEE
+ * @shm_unregister: unregister shared memory buffer in TEE
*/
struct tee_driver_ops {
void (*get_version)(struct tee_device *teedev,
@@ -94,6 +100,9 @@ struct tee_driver_ops {
struct tee_param *param);
int (*supp_send)(struct tee_context *ctx, u32 ret, u32 num_params,
struct tee_param *param);
+ int (*shm_register)(struct tee_context *ctx, struct tee_shm *shm,
+ struct page **pages, size_t num_pages);
+ int (*shm_unregister)(struct tee_context *ctx, struct tee_shm *shm);
};

/**
@@ -302,6 +311,30 @@ void *tee_get_drvdata(struct tee_device *teedev);
struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags);

/**
+ * tee_shm_priv_alloc() - Allocate shared memory privately
+ * @dev: Device that allocates the shared memory
+ * @size: Requested size of shared memory
+ *
+ * Allocates shared memory buffer that is not associated with any client
+ * context. Such buffers are owned by TEE driver and used for internal calls.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size);
+
+/**
+ * tee_shm_register() - Register shared memory buffer
+ * @ctx: Context that registers the shared memory
+ * @addr: Address is userspace of the shared buffer
+ * @length: Length of the shared buffer
+ * @flags: Flags setting properties for the requested shared memory.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
+ size_t length, u32 flags);
+
+/**
* tee_shm_free() - Free shared memory
* @shm: Handle to shared memory to free
*/
@@ -366,4 +399,11 @@ int tee_shm_get_id(struct tee_shm *shm);
*/
struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);

+/**
+ * tee_shm_is_registered() - Check if shared memory object in registered in TEE
+ * @shm: Shared memory handle
+ * @returns true if object is registered in TEE
+ */
+bool tee_shm_is_registered(struct tee_shm *shm);
+
#endif /*__TEE_DRV_H*/
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 688782e..d41a07a 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -50,6 +50,7 @@

#define TEE_GEN_CAP_GP (1 << 0)/* GlobalPlatform compliant TEE */
#define TEE_GEN_CAP_PRIVILEGED (1 << 1)/* Privileged device (for supplicant) */
+#define TEE_GEN_CAP_REG_MEM (1 << 2)/* Supports registering shared memory */

/*
* TEE Implementation ID
@@ -332,6 +333,35 @@ struct tee_iocl_supp_send_arg {
#define TEE_IOC_SUPPL_SEND _IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 7, \
struct tee_ioctl_buf_data)

+/**
+ * struct tee_ioctl_shm_register_data - Shared memory register argument
+ * @addr: [in] Start address of shared memory to register
+ * @length: [in/out] Length of shared memory to register
+ * @flags: [in/out] Flags to/from registration.
+ * @id: [out] Identifier of the shared memory
+ *
+ * The flags field should currently be zero as input. Updated by the call
+ * with actual flags as defined by TEE_IOCTL_SHM_* above.
+ * This structure is used as argument for TEE_IOC_SHM_REGISTER below.
+ */
+struct tee_ioctl_shm_register_data {
+ __u64 addr;
+ __u64 length;
+ __u32 flags;
+ __s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_REGISTER - Register shared memory argument
+ *
+ * Registers shared memory between the user space process and secure OS.
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The shared memory is unregisterred when the descriptor is closed.
+ */
+#define TEE_IOC_SHM_REGISTER _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 9, \
+ struct tee_ioctl_shm_register_data)
/*
* Five syscalls are used when communicating with the TEE driver.
* open(): opens the device associated with the driver
--
2.7.4
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