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[backport,5.15,v2] optee: use driver internal tee_context for some rpc

Message ID 20220221223105.1423455-1-jens.wiklander@linaro.org
State New
Headers show
Series [backport,5.15,v2] optee: use driver internal tee_context for some rpc | expand

Commit Message

Jens Wiklander Feb. 21, 2022, 10:31 p.m. UTC
commit aceeafefff736057e8f93f19bbfbef26abd94604 upstream

Adds a driver private tee_context to struct optee.

The new driver internal tee_context is used 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 # 1e2c3ef0496e tee: export teedev_open() and teedev_close_context()
Cc: stable@vger.kernel.org
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
[JW: backport to 5.15-stable + update commit message]
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
Hi,

This is an update to the previous patch posted with the same name.

Please note that this patch depends on 1e2c3ef0496e ("tee: export
teedev_open() and teedev_close_context()") which needs be cherry-picked
before this patch is applied.

Thanks,
Jens

 drivers/tee/optee/core.c          | 8 ++++++++
 drivers/tee/optee/optee_private.h | 2 ++
 drivers/tee/optee/rpc.c           | 8 +++++---
 3 files changed, 15 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index 5363ebebfc35..50c0d839fe75 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -588,6 +588,7 @@  static int optee_remove(struct platform_device *pdev)
 	/* Unregister OP-TEE specific client devices on TEE bus */
 	optee_unregister_devices();
 
+	teedev_close_context(optee->ctx);
 	/*
 	 * Ask OP-TEE to free all cached shared memory objects to decrease
 	 * reference counters and also avoid wild pointers in secure world
@@ -633,6 +634,7 @@  static int optee_probe(struct platform_device *pdev)
 	struct optee *optee = NULL;
 	void *memremaped_shm = NULL;
 	struct tee_device *teedev;
+	struct tee_context *ctx;
 	u32 sec_caps;
 	int rc;
 
@@ -719,6 +721,12 @@  static int optee_probe(struct platform_device *pdev)
 	optee_supp_init(&optee->supp);
 	optee->memremaped_shm = memremaped_shm;
 	optee->pool = pool;
+	ctx = teedev_open(optee->teedev);
+	if (IS_ERR(ctx)) {
+		rc = PTR_ERR(ctx);
+		goto err;
+	}
+	optee->ctx = ctx;
 
 	/*
 	 * Ensure that there are no pre-existing shm objects before enabling
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index f6bb4a763ba9..ea09533e30cd 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -70,6 +70,7 @@  struct optee_supp {
  * struct optee - main service struct
  * @supp_teedev:	supplicant device
  * @teedev:		client device
+ * @ctx:		driver internal TEE context
  * @invoke_fn:		function to issue smc or hvc
  * @call_queue:		queue of threads waiting to call @invoke_fn
  * @wait_queue:		queue of threads from secure world waiting for a
@@ -87,6 +88,7 @@  struct optee {
 	struct tee_device *supp_teedev;
 	struct tee_device *teedev;
 	optee_invoke_fn *invoke_fn;
+	struct tee_context *ctx;
 	struct optee_call_queue call_queue;
 	struct optee_wait_queue wait_queue;
 	struct optee_supp supp;
diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
index efbaff7ad7e5..456833d82007 100644
--- a/drivers/tee/optee/rpc.c
+++ b/drivers/tee/optee/rpc.c
@@ -285,6 +285,7 @@  static struct tee_shm *cmd_alloc_suppl(struct tee_context *ctx, size_t sz)
 }
 
 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)
 {
@@ -314,7 +315,8 @@  static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
 		shm = 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;
@@ -471,7 +473,7 @@  static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
 		break;
 	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);
@@ -502,7 +504,7 @@  void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param,
 
 	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);