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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Lars Persson <larper@axis.com>,
        Sumit Garg <sumit.garg@linaro.org>,
        Jens Wiklander <jens.wiklander@linaro.org>
Subject: [PATCH 5.16 088/227] optee: use driver internal tee_context for some rpc
Date:   Mon, 21 Feb 2022 09:48:27 +0100
Message-Id: <20220221084937.806250169@linuxfoundation.org>
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From: Jens Wiklander <jens.wiklander@linaro.org>

commit aceeafefff736057e8f93f19bbfbef26abd94604 upstream.

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>
[JW: backport to 5.16-stable + update commit message]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tee/optee/core.c          |    1 
 drivers/tee/optee/ffa_abi.c       |   70 +++++++++++++++++++++-----------------
 drivers/tee/optee/optee_private.h |    4 +-
 drivers/tee/optee/smc_abi.c       |   13 +++++--
 4 files changed, 54 insertions(+), 34 deletions(-)

--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -157,6 +157,7 @@ void optee_remove_common(struct optee *o
 	/* Unregister OP-TEE specific client devices on TEE bus */
 	optee_unregister_devices();
 
+	teedev_close_context(optee->ctx);
 	/*
 	 * The two devices have to be unregistered before we can free the
 	 * other resources.
--- 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_ff
  */
 
 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_
 		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(stru
 	}
 }
 
-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(struc
 		 * 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;
@@ -802,7 +802,9 @@ static int optee_ffa_probe(struct ffa_de
 {
 	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;
 
@@ -822,12 +824,12 @@ static int optee_ffa_probe(struct ffa_de
 	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;
@@ -838,7 +840,7 @@ static int optee_ffa_probe(struct ffa_de
 				  optee);
 	if (IS_ERR(teedev)) {
 		rc = PTR_ERR(teedev);
-		goto err;
+		goto err_free_pool;
 	}
 	optee->teedev = teedev;
 
@@ -846,46 +848,54 @@ static int optee_ffa_probe(struct ffa_de
 				  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_wait_queue_init(&optee->wait_queue);
 	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_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();
+	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;
 }
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -123,9 +123,10 @@ struct optee_ops {
 /**
  * struct optee - main service struct
  * @supp_teedev:	supplicant device
+ * @teedev:		client device
  * @ops:		internal callbacks for different ways to reach secure
  *			world
- * @teedev:		client device
+ * @ctx:		driver internal TEE context
  * @smc:		specific to SMC ABI
  * @ffa:		specific to FF-A ABI
  * @call_queue:		queue of threads waiting to call @invoke_fn
@@ -142,6 +143,7 @@ struct optee {
 	struct tee_device *supp_teedev;
 	struct tee_device *teedev;
 	const struct optee_ops *ops;
+	struct tee_context *ctx;
 	union {
 		struct optee_smc smc;
 		struct optee_ffa ffa;
--- a/drivers/tee/optee/smc_abi.c
+++ b/drivers/tee/optee/smc_abi.c
@@ -608,6 +608,7 @@ static void handle_rpc_func_cmd_shm_free
 }
 
 static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
+					  struct optee *optee,
 					  struct optee_msg_arg *arg,
 					  struct optee_call_ctx *call_ctx)
 {
@@ -637,7 +638,8 @@ static void handle_rpc_func_cmd_shm_allo
 		shm = optee_rpc_cmd_alloc_suppl(ctx, sz);
 		break;
 	case OPTEE_RPC_SHM_TYPE_KERNEL:
-		shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED | TEE_SHM_PRIV);
+		shm = tee_shm_alloc(optee->ctx, sz,
+				    TEE_SHM_MAPPED | TEE_SHM_PRIV);
 		break;
 	default:
 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
@@ -733,7 +735,7 @@ static void handle_rpc_func_cmd(struct t
 	switch (arg->cmd) {
 	case OPTEE_RPC_CMD_SHM_ALLOC:
 		free_pages_list(call_ctx);
-		handle_rpc_func_cmd_shm_alloc(ctx, arg, call_ctx);
+		handle_rpc_func_cmd_shm_alloc(ctx, optee, arg, call_ctx);
 		break;
 	case OPTEE_RPC_CMD_SHM_FREE:
 		handle_rpc_func_cmd_shm_free(ctx, arg);
@@ -762,7 +764,7 @@ static void optee_handle_rpc(struct tee_
 
 	switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
 	case OPTEE_SMC_RPC_FUNC_ALLOC:
-		shm = tee_shm_alloc(ctx, param->a1,
+		shm = tee_shm_alloc(optee->ctx, param->a1,
 				    TEE_SHM_MAPPED | TEE_SHM_PRIV);
 		if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) {
 			reg_pair_from_64(&param->a1, &param->a2, pa);
@@ -1207,6 +1209,7 @@ static int optee_probe(struct platform_d
 	struct optee *optee = NULL;
 	void *memremaped_shm = NULL;
 	struct tee_device *teedev;
+	struct tee_context *ctx;
 	u32 sec_caps;
 	int rc;
 
@@ -1284,6 +1287,10 @@ static int optee_probe(struct platform_d
 	optee_supp_init(&optee->supp);
 	optee->smc.memremaped_shm = memremaped_shm;
 	optee->pool = pool;
+	ctx = teedev_open(optee->teedev);
+	if (IS_ERR(ctx))
+		goto err;
+	optee->ctx = ctx;
 
 	/*
 	 * Ensure that there are no pre-existing shm objects before enabling