Re: [PATCH v2 4/8] tee: add TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF

Hi,

On Sun, Feb 02, 2025 at 06:43:32PM -0800, Amirreza Zarrabi wrote:

The TEE subsystem allows session-based access to trusted services, requiring a session to be established to receive a service. This is not suitable for an environment that represents services as objects. An object supports various operations that a client can invoke, potentially generating a result or a new object that can be invoked independently of the original object.

Add TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT/OUTPUT/INOUT to represent an object. Objects may reside in either TEE or userspace. To invoke an object in TEE, introduce a new ioctl. Use the existing SUPPL_RECV and SUPPL_SEND to invoke an object in userspace.

Signed-off-by: Amirreza Zarrabi quic_azarrabi@quicinc.com

drivers/tee/tee_core.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/tee_core.h | 4 +++ include/linux/tee_drv.h | 6 ++++ include/uapi/linux/tee.h | 41 +++++++++++++++++++---- 4 files changed, 130 insertions(+), 6 deletions(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 9f4b9a995e16..fe435772688c 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -379,6 +379,7 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params, switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) { case TEE_IOCTL_PARAM_ATTR_TYPE_NONE: case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
  break;
  

  case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:

@@ -396,6 +397,11 @@ static int params_from_user(struct tee_context *ctx, struct tee_param *params, return -EFAULT; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT:
  

• 	params[n].u.objref.id = ip.a;
  

• 	params[n].u.objref.flags = ip.b;
  

• 	break;
  

  case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:

@@ -469,6 +475,12 @@ static int params_to_user(struct tee_ioctl_param __user *uparams, if (put_user((u64)p->u.ubuf.size, &up->b)) return -EFAULT; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT:
  

• 	if (put_user(p->u.objref.id, &up->a) ||
  

• 	    put_user(p->u.objref.flags, &up->b))
  

• 		return -EFAULT;
  

• 	break;
  

  case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT: if (put_user((u64)p->u.memref.size, &up->b))

@@ -621,6 +633,66 @@ static int tee_ioctl_invoke(struct tee_context *ctx, return rc; } +static int tee_ioctl_object_invoke(struct tee_context *ctx,

• 		   struct tee_ioctl_buf_data __user *ubuf)
  

+{

• int rc;
• size_t n;
• struct tee_ioctl_buf_data buf;
• struct tee_ioctl_object_invoke_arg __user *uarg;
• struct tee_ioctl_object_invoke_arg arg;
• struct tee_ioctl_param __user *uparams = NULL;
• struct tee_param *params = NULL;
• if (!ctx->teedev->desc->ops->object_invoke_func)

• return -EINVAL;
  

• if (copy_from_user(&buf, ubuf, sizeof(buf)))

• return -EFAULT;
  

• if (buf.buf_len > TEE_MAX_ARG_SIZE ||

•    buf.buf_len < sizeof(struct tee_ioctl_object_invoke_arg))
  

• return -EINVAL;
  

• uarg = u64_to_user_ptr(buf.buf_ptr);
• if (copy_from_user(&arg, uarg, sizeof(arg)))

• return -EFAULT;
  

• if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)

• return -EINVAL;
  

• if (arg.num_params) {

• params = kcalloc(arg.num_params, sizeof(struct tee_param),
  

• 		 GFP_KERNEL);
  

• if (!params)
  

• 	return -ENOMEM;
  

• uparams = uarg->params;
  

• rc = params_from_user(ctx, params, arg.num_params, uparams);
  

• if (rc)
  

• 	goto out;
  

• }
• rc = ctx->teedev->desc->ops->object_invoke_func(ctx, &arg, params);
• if (rc)

• goto out;
  

• if (put_user(arg.ret, &uarg->ret)) {

• rc = -EFAULT;
  

• goto out;
  

• }
• rc = params_to_user(uparams, arg.num_params, params);

+out:

• if (params) {

• /* Decrease ref count for all valid shared memory pointers */
  

• for (n = 0; n < arg.num_params; n++)
  

• 	if (tee_param_is_memref(params + n) &&
  

• 	    params[n].u.memref.shm)
  

• 		tee_shm_put(params[n].u.memref.shm);
  

• kfree(params);
  

• }
• return rc;

+}

static int tee_ioctl_cancel(struct tee_context *ctx, struct tee_ioctl_cancel_arg __user *uarg) { @@ -676,6 +748,12 @@ static int params_to_supp(struct tee_context *ctx, ip.b = p->u.ubuf.size; ip.c = 0; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT:
  

• 	ip.a = p->u.objref.id;
  

• 	ip.b = p->u.objref.flags;
  

• 	ip.c = 0;
  

• 	break;
  

  case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:

@@ -783,6 +861,11 @@ static int params_from_supp(struct tee_param *params, size_t num_params, p->u.ubuf.uaddr = u64_to_user_ptr(ip.a); p->u.ubuf.size = ip.b; break;

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT:
  

• case TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT:
  

• 	p->u.objref.id = ip.a;
  

• 	p->u.objref.flags = ip.b;
  

• 	break;
  

  case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT: case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT: /*

@@ -863,6 +946,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return tee_ioctl_open_session(ctx, uarg); case TEE_IOC_INVOKE: return tee_ioctl_invoke(ctx, uarg);

• case TEE_IOC_OBJECT_INVOKE:

• return tee_ioctl_object_invoke(ctx, uarg);
  

  case TEE_IOC_CANCEL: return tee_ioctl_cancel(ctx, uarg); case TEE_IOC_CLOSE_SESSION:

diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h index 8a4c9e30b652..ffb04c946c70 100644 --- a/include/linux/tee_core.h +++ b/include/linux/tee_core.h @@ -72,6 +72,7 @@ struct tee_device {

• @close_session: close a session
• @system_session: declare session as a system session
• @invoke_func: invoke a trusted function

• • @object_invoke_func: invoke an object

invoke a TEE object?

• @cancel_req: request cancel of an ongoing invoke or open
• @supp_recv: called for supplicant to get a command
• @supp_send: called for supplicant to send a response

@@ -97,6 +98,9 @@ struct tee_driver_ops { int (*invoke_func)(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg, struct tee_param *param);

• int (*object_invoke_func)(struct tee_context *ctx,

• 		  struct tee_ioctl_object_invoke_arg *arg,
  

• 		  struct tee_param *param);
  

  int (*cancel_req)(struct tee_context *ctx, u32 cancel_id, u32 session); int (*supp_recv)(struct tee_context *ctx, u32 *func, u32 *num_params, struct tee_param *param);

diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 130782d4d5f6..16dad7a21910 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -87,6 +87,11 @@ struct tee_param_ubuf { size_t size; }; +struct tee_param_objref {

• u64 id;
• u64 flags;

+};

struct tee_param_value { u64 a; u64 b; @@ -97,6 +102,7 @@ struct tee_param { u64 attr; union { struct tee_param_memref memref;

• struct tee_param_objref objref;
  

  struct tee_param_ubuf ubuf; struct tee_param_value value; } u;

diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h index 4a1dcfb4290e..0aef647d4a34 100644 --- a/include/uapi/linux/tee.h +++ b/include/uapi/linux/tee.h @@ -48,8 +48,10 @@ #define TEE_GEN_CAP_PRIVILEGED (1 << 1)/* Privileged device (for supplicant) */ #define TEE_GEN_CAP_REG_MEM (1 << 2)/* Supports registering shared memory */ #define TEE_GEN_CAP_MEMREF_NULL (1 << 3)/* NULL MemRef support */ +#define TEE_GEN_CAP_OBJREF (1 << 4)/* Supports generic object reference */ -#define TEE_MEMREF_NULL (__u64)(-1) /* NULL MemRef Buffer */ +#define TEE_MEMREF_NULL ((__u64)(-1)) /* NULL MemRef Buffer */ +#define TEE_OBJREF_NULL ((__u64)(-1)) /* NULL ObjRef Object */ /*

• TEE Implementation ID

@@ -158,6 +160,13 @@ struct tee_ioctl_buf_data { #define TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_OUTPUT 9 #define TEE_IOCTL_PARAM_ATTR_TYPE_UBUF_INOUT 10 /* input and output */ +/*

• • These defines object reference parameters.
• */

+#define TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INPUT 11 +#define TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_OUTPUT 12 +#define TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF_INOUT 13

/*

• Mask for the type part of the attribute, leaves room for more types

*/ @@ -195,15 +204,16 @@ struct tee_ioctl_buf_data {

• @attr: attributes
• @a: if a memref, offset into the shared memory object,

• else if a ubuf, address into the user buffer,
  

• • else a value parameter
    

• • @b: if a memref or ubuf, size of the buffer, else a value parameter

• • else if an objref, object identifier, else a value parameter
    

• • @b: if a memref or ubuf, size of the buffer,

• • else if objref, a flag for object, else a value parameter
    

flags for the object?

• @c: if a memref, shared memory identifier, else a value parameter
• @attr & TEE_PARAM_ATTR_TYPE_MASK indicates if memref, ubuf, or value is
• used in the union. TEE_PARAM_ATTR_TYPE_VALUE_* indicates value,

• • TEE_PARAM_ATTR_TYPE_MEMREF_* indicates memref, and TEE_PARAM_ATTR_TYPE_UBUF_*
• • indicates ubuf. TEE_PARAM_ATTR_TYPE_NONE indicates that none of the members
• • are used.

• • TEE_PARAM_ATTR_TYPE_MEMREF_* indicates memref, TEE_PARAM_ATTR_TYPE_UBUF_*
• • indicates ubuf, and TEE_PARAM_ATTR_TYPE_OBJREF_* indicates objref.
• • TEE_PARAM_ATTR_TYPE_NONE indicates that none of the members are used.
  • Shared memory is allocated with TEE_IOC_SHM_ALLOC which returns an
  • identifier representing the shared memory object. A memref can reference

@@ -411,4 +421,23 @@ struct tee_ioctl_shm_register_data {

• munmap(): unmaps previously shared memory

*/ +/**

• • struct tee_ioctl_invoke_func_arg - Invokes an object in a Trusted Application.

Please drop the terminating '.'.

Thanks, Jens

• • @object: [in] Object id
• • @op: [in] Object operation, specific to the object
• • @ret: [out] return value
• • @num_params [in] number of parameters following this struct
• */

+struct tee_ioctl_object_invoke_arg {

• __u64 object;
• __u32 op;
• __u32 ret;
• __u32 num_params;
• /* num_params tells the actual number of element in params */
• struct tee_ioctl_param params[];

+};

+#define TEE_IOC_OBJECT_INVOKE _IOR(TEE_IOC_MAGIC, TEE_IOC_BASE + 10, \

• 		     struct tee_ioctl_buf_data)
  

#endif /*__TEE_H*/

-- 2.34.1