optee: use driver internal tee_context for some rpc

Adds a driver private tee_context by moving the tee_context in struct
optee_notif to struct optee. This tee_context was previously used when
doing internal calls to secure world to deliver notification.

The new driver internal tee_context is now also when allocating driver
private shared memory. This decouples the shared memory object from its
original tee_context. This is needed when the life time of such a memory
allocation outlives the client tee_context.

This patch fixes the problem described below:

The addition of a shutdown hook by commit f25889f93184 ("optee: fix tee out
of memory failure seen during kexec reboot") introduced a kernel shutdown
regression that can be triggered after running the OP-TEE xtest suites.

Once the shutdown hook is called it is not possible to communicate any more
with the supplicant process because the system is not scheduling task any
longer. Thus if the optee driver shutdown path receives a supplicant RPC
request from the OP-TEE we will deadlock the kernel's shutdown.

Fixes: f25889f93184 ("optee: fix tee out of memory failure seen during kexec reboot")
Fixes: 217e0250cccb ("tee: use reference counting for tee_context")
Reported-by: Lars Persson <larper@axis.com>
Cc: stable@vger.kernel.org
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

1 files changed, 43 insertions, 34 deletions

diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
index 20a1b1a3d965..545f61af1248 100644
--- a/drivers/tee/optee/ffa_abi.c
+++ b/drivers/tee/optee/ffa_abi.c
@@ -424,6 +424,7 @@ static struct tee_shm_pool_mgr *optee_ffa_shm_pool_alloc_pages(void)
  */
 
 static void handle_ffa_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
+					      struct optee *optee,
 					      struct optee_msg_arg *arg)
 {
 	struct tee_shm *shm;
@@ -439,7 +440,7 @@ static void handle_ffa_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
 		shm = optee_rpc_cmd_alloc_suppl(ctx, arg->params[0].u.value.b);
 		break;
 	case OPTEE_RPC_SHM_TYPE_KERNEL:
-		shm = tee_shm_alloc(ctx, arg->params[0].u.value.b,
+		shm = tee_shm_alloc(optee->ctx, arg->params[0].u.value.b,
 				    TEE_SHM_MAPPED | TEE_SHM_PRIV);
 		break;
 	default:
@@ -493,14 +494,13 @@ err_bad_param:
 }
 
 static void handle_ffa_rpc_func_cmd(struct tee_context *ctx,
+				    struct optee *optee,
 				    struct optee_msg_arg *arg)
 {
-	struct optee *optee = tee_get_drvdata(ctx->teedev);
-
 	arg->ret_origin = TEEC_ORIGIN_COMMS;
 	switch (arg->cmd) {
 	case OPTEE_RPC_CMD_SHM_ALLOC:
-		handle_ffa_rpc_func_cmd_shm_alloc(ctx, arg);
+		handle_ffa_rpc_func_cmd_shm_alloc(ctx, optee, arg);
 		break;
 	case OPTEE_RPC_CMD_SHM_FREE:
 		handle_ffa_rpc_func_cmd_shm_free(ctx, optee, arg);
@@ -510,12 +510,12 @@ static void handle_ffa_rpc_func_cmd(struct tee_context *ctx,
 	}
 }
 
-static void optee_handle_ffa_rpc(struct tee_context *ctx, u32 cmd,
-				 struct optee_msg_arg *arg)
+static void optee_handle_ffa_rpc(struct tee_context *ctx, struct optee *optee,
+				 u32 cmd, struct optee_msg_arg *arg)
 {
 	switch (cmd) {
 	case OPTEE_FFA_YIELDING_CALL_RETURN_RPC_CMD:
-		handle_ffa_rpc_func_cmd(ctx, arg);
+		handle_ffa_rpc_func_cmd(ctx, optee, arg);
 		break;
 	case OPTEE_FFA_YIELDING_CALL_RETURN_INTERRUPT:
 		/* Interrupt delivered by now */
@@ -582,7 +582,7 @@ static int optee_ffa_yielding_call(struct tee_context *ctx,
 		 * above.
 		 */
 		cond_resched();
-		optee_handle_ffa_rpc(ctx, data->data1, rpc_arg);
+		optee_handle_ffa_rpc(ctx, optee, data->data1, rpc_arg);
 		cmd = OPTEE_FFA_YIELDING_CALL_RESUME;
 		data->data0 = cmd;
 		data->data1 = 0;
@@ -793,7 +793,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 {
 	const struct ffa_dev_ops *ffa_ops;
 	unsigned int rpc_arg_count;
+	struct tee_shm_pool *pool;
 	struct tee_device *teedev;
+	struct tee_context *ctx;
 	struct optee *optee;
 	int rc;
 
@@ -813,12 +815,12 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 	if (!optee)
 		return -ENOMEM;
 
-	optee->pool = optee_ffa_config_dyn_shm();
-	if (IS_ERR(optee->pool)) {
-		rc = PTR_ERR(optee->pool);
-		optee->pool = NULL;
-		goto err;
+	pool = optee_ffa_config_dyn_shm();
+	if (IS_ERR(pool)) {
+		rc = PTR_ERR(pool);
+		goto err_free_optee;
 	}
+	optee->pool = pool;
 
 	optee->ops = &optee_ffa_ops;
 	optee->ffa.ffa_dev = ffa_dev;
@@ -829,7 +831,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 				  optee);
 	if (IS_ERR(teedev)) {
 		rc = PTR_ERR(teedev);
-		goto err;
+		goto err_free_pool;
 	}
 	optee->teedev = teedev;
 
@@ -837,50 +839,57 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
 				  optee);
 	if (IS_ERR(teedev)) {
 		rc = PTR_ERR(teedev);
-		goto err;
+		goto err_unreg_teedev;
 	}
 	optee->supp_teedev = teedev;
 
 	rc = tee_device_register(optee->teedev);
 	if (rc)
-		goto err;
+		goto err_unreg_supp_teedev;
 
 	rc = tee_device_register(optee->supp_teedev);
 	if (rc)
-		goto err;
+		goto err_unreg_supp_teedev;
 
 	rc = rhashtable_init(&optee->ffa.global_ids, &shm_rhash_params);
 	if (rc)
-		goto err;
+		goto err_unreg_supp_teedev;
 	mutex_init(&optee->ffa.mutex);
 	mutex_init(&optee->call_queue.mutex);
 	INIT_LIST_HEAD(&optee->call_queue.waiters);
 	optee_supp_init(&optee->supp);
 	ffa_dev_set_drvdata(ffa_dev, optee);
+	ctx = teedev_open(optee->teedev);
+	if (IS_ERR(ctx))
+		goto err_rhashtable_free;
+	optee->ctx = ctx;
 	rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE);
-	if (rc) {
-		optee_ffa_remove(ffa_dev);
-		return rc;
-	}
+	if (rc)
+		goto err_close_ctx;
 
 	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
-	if (rc) {
-		optee_ffa_remove(ffa_dev);
-		return rc;
-	}
+	if (rc)
+		goto err_unregister_devices;
 
 	pr_info("initialized driver\n");
 	return 0;
-err:
-	/*
-	 * tee_device_unregister() is safe to call even if the
-	 * devices hasn't been registered with
-	 * tee_device_register() yet.
-	 */
+
+err_unregister_devices:
+	optee_unregister_devices();
+	optee_notif_uninit(optee);
+err_close_ctx:
+	teedev_close_context(ctx);
+err_rhashtable_free:
+	rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
+	optee_supp_uninit(&optee->supp);
+	mutex_destroy(&optee->call_queue.mutex);
+err_unreg_supp_teedev:
 	tee_device_unregister(optee->supp_teedev);
+err_unreg_teedev:
 	tee_device_unregister(optee->teedev);
-	if (optee->pool)
-		tee_shm_pool_free(optee->pool);
+err_free_pool:
+	tee_shm_pool_free(pool);
+err_free_optee:
 	kfree(optee);
 	return rc;
 }