From 42bf4152d8a79f89f5456dee63a1f364fbce2dd6 Mon Sep 17 00:00:00 2001 From: Sumit Garg Date: Tue, 29 Jan 2019 11:19:36 +0530 Subject: [PATCH] tee: add supp_nowait flag in tee_context struct This flag indicates that requests in this context should not wait for tee-supplicant daemon to be started if not present and just return with an error code. It is needed for requests which should be non-blocking in nature like ones arising from TEE based kernel drivers or any in kernel api that uses TEE internal client interface. Signed-off-by: Sumit Garg Reviewed-by: Daniel Thompson Signed-off-by: Jens Wiklander --- drivers/tee/optee/supp.c | 10 +++++++++- drivers/tee/tee_core.c | 13 +++++++++++++ include/linux/tee_drv.h | 6 ++++++ 3 files changed, 28 insertions(+), 1 deletion(-) diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c index 43626e15703a..92f56b8645e3 100644 --- a/drivers/tee/optee/supp.c +++ b/drivers/tee/optee/supp.c @@ -88,10 +88,18 @@ u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params, { struct optee *optee = tee_get_drvdata(ctx->teedev); struct optee_supp *supp = &optee->supp; - struct optee_supp_req *req = kzalloc(sizeof(*req), GFP_KERNEL); + struct optee_supp_req *req; bool interruptable; u32 ret; + /* + * Return in case there is no supplicant available and + * non-blocking request. + */ + if (!supp->ctx && ctx->supp_nowait) + return TEEC_ERROR_COMMUNICATION; + + req = kzalloc(sizeof(*req), GFP_KERNEL); if (!req) return TEEC_ERROR_OUT_OF_MEMORY; diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 7b2bb4c50058..adf2588282fc 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -106,6 +106,11 @@ static int tee_open(struct inode *inode, struct file *filp) if (IS_ERR(ctx)) return PTR_ERR(ctx); + /* + * Default user-space behaviour is to wait for tee-supplicant + * if not present for any requests in this context. + */ + ctx->supp_nowait = false; filp->private_data = ctx; return 0; } @@ -982,6 +987,14 @@ tee_client_open_context(struct tee_context *start, } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM); put_device(put_dev); + /* + * Default behaviour for in kernel client is to not wait for + * tee-supplicant if not present for any requests in this context. + * Also this flag could be configured again before call to + * tee_client_open_session() if any in kernel client requires + * different behaviour. + */ + ctx->supp_nowait = true; return ctx; } EXPORT_SYMBOL_GPL(tee_client_open_context); diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 6cfe05893a76..5076502c07d7 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -47,6 +47,11 @@ struct tee_shm_pool; * @releasing: flag that indicates if context is being released right now. * It is needed to break circular dependency on context during * shared memory release. + * @supp_nowait: flag that indicates that requests in this context should not + * wait for tee-supplicant daemon to be started if not present + * and just return with an error code. It is needed for requests + * that arises from TEE based kernel drivers that should be + * non-blocking in nature. */ struct tee_context { struct tee_device *teedev; @@ -54,6 +59,7 @@ struct tee_context { void *data; struct kref refcount; bool releasing; + bool supp_nowait; }; struct tee_param_memref { -- 2.11.0