[PATCH v4 1/7] tee: qcomtee: Track the object invocation context

[Harshal Dev <harshal.dev@oss.qualcomm.com>]

QCOMTEE needs to distinguish between object invocations arriving from
kernel clients and user-space clients in order to correctly marshal
UBUF parameters and decide whether certain operations should be permitted.

Introduce an enum tee_object_invoke_origin to allow clients to indicate
the context of the TEE object invocation, and add a kernel_ctx flag to the
QCOMTEE context so the TEE back-end can track it.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Harshal Dev <harshal.dev@oss.qualcomm.com>
---
 drivers/tee/qcomtee/call.c           | 12 +++++++++---
 drivers/tee/qcomtee/qcomtee_object.h |  8 ++++++--
 drivers/tee/tee_core.c               |  3 ++-
 include/linux/tee_core.h             |  8 +++++++-
 4 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/tee/qcomtee/call.c b/drivers/tee/qcomtee/call.c
index 4a597eeaf174..3de54af45719 100644
--- a/drivers/tee/qcomtee/call.c
+++ b/drivers/tee/qcomtee/call.c
@@ -388,20 +388,26 @@ static int qcomtee_root_object_check(u32 op, struct tee_param *params,
  * @ctx: TEE context.
  * @arg: ioctl arguments.
  * @params: parameters for the object.
+ * @origin: origin of the object invocation (kernel or user-space).
  *
  * Return: On success, returns 0; on failure, returns < 0.
  */
 static int qcomtee_object_invoke(struct tee_context *ctx,
 				 struct tee_ioctl_object_invoke_arg *arg,
-				 struct tee_param *params)
+				 struct tee_param *params,
+				 enum tee_object_invoke_origin origin)
 {
 	struct qcomtee_context_data *ctxdata = ctx->data;
 	struct qcomtee_object *object;
+	bool kernel_ctx = false;
 	int i, ret, result;
 
 	if (qcomtee_params_check(params, arg->num_params))
 		return -EINVAL;
 
+	if (origin == TEE_OBJECT_INVOKE_KERNEL)
+		kernel_ctx = true;
+
 	/* First, handle reserved operations: */
 	if (arg->op == QCOMTEE_MSG_OBJECT_OP_RELEASE) {
 		del_qtee_object(arg->id, ctxdata);
@@ -411,7 +417,7 @@ static int qcomtee_object_invoke(struct tee_context *ctx,
 
 	/* Otherwise, invoke a QTEE object: */
 	struct qcomtee_object_invoke_ctx *oic __free(kfree) =
-		qcomtee_object_invoke_ctx_alloc(ctx);
+		qcomtee_object_invoke_ctx_alloc(ctx, kernel_ctx);
 	if (!oic)
 		return -ENOMEM;
 
@@ -648,7 +654,7 @@ static void qcomtee_get_qtee_feature_list(struct tee_context *ctx, u32 id,
 	int result;
 
 	struct qcomtee_object_invoke_ctx *oic __free(kfree) =
-		qcomtee_object_invoke_ctx_alloc(ctx);
+		qcomtee_object_invoke_ctx_alloc(ctx, true);
 	if (!oic)
 		return;
 
diff --git a/drivers/tee/qcomtee/qcomtee_object.h b/drivers/tee/qcomtee/qcomtee_object.h
index d5de02dcef3b..5f40617361fc 100644
--- a/drivers/tee/qcomtee/qcomtee_object.h
+++ b/drivers/tee/qcomtee/qcomtee_object.h
@@ -147,6 +147,7 @@ static inline int qcomtee_args_len(struct qcomtee_arg *args)
  * struct qcomtee_object_invoke_ctx - QTEE context for object invocation.
  * @ctx: TEE context for this invocation.
  * @flags: flags for the invocation context.
+ * @kernel_ctx: flag that indicates this context is owned by a kernel client.
  * @errno: error code for the invocation.
  * @object: current object invoked in this callback context.
  * @u: array of arguments for the current invocation (+1 for ending arg).
@@ -159,6 +160,7 @@ static inline int qcomtee_args_len(struct qcomtee_arg *args)
 struct qcomtee_object_invoke_ctx {
 	struct tee_context *ctx;
 	unsigned long flags;
+	bool kernel_ctx;
 	int errno;
 
 	struct qcomtee_object *object;
@@ -173,13 +175,15 @@ struct qcomtee_object_invoke_ctx {
 };
 
 static inline struct qcomtee_object_invoke_ctx *
-qcomtee_object_invoke_ctx_alloc(struct tee_context *ctx)
+qcomtee_object_invoke_ctx_alloc(struct tee_context *ctx, bool kernel_ctx)
 {
 	struct qcomtee_object_invoke_ctx *oic;
 
 	oic = kzalloc_obj(*oic);
-	if (oic)
+	if (oic) {
 		oic->ctx = ctx;
+		oic->kernel_ctx = kernel_ctx;
+	}
 	return oic;
 }
 
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 1aac50c7c1de..30901390149c 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -701,7 +701,8 @@ static int tee_ioctl_object_invoke(struct tee_context *ctx,
 			goto out;
 	}
 
-	rc = ctx->teedev->desc->ops->object_invoke_func(ctx, &arg, params);
+	rc = ctx->teedev->desc->ops->object_invoke_func(ctx, &arg, params,
+							TEE_OBJECT_INVOKE_USERSPACE);
 	if (rc)
 		goto out;
 
diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h
index f993d5118edd..bcb5418d6fdc 100644
--- a/include/linux/tee_core.h
+++ b/include/linux/tee_core.h
@@ -73,6 +73,11 @@ struct tee_device {
 	struct tee_shm_pool *pool;
 };
 
+enum tee_object_invoke_origin {
+	TEE_OBJECT_INVOKE_USERSPACE,
+	TEE_OBJECT_INVOKE_KERNEL,
+};
+
 /**
  * struct tee_driver_ops - driver operations vtable
  * @get_version:	returns version of driver
@@ -117,7 +122,8 @@ struct tee_driver_ops {
 			   struct tee_param *param);
 	int (*object_invoke_func)(struct tee_context *ctx,
 				  struct tee_ioctl_object_invoke_arg *arg,
-				  struct tee_param *param);
+				  struct tee_param *param,
+				  enum tee_object_invoke_origin origin);
 	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);

-- 
2.34.1