Return-Path: Received: from mail-ua1-f65.google.com ([209.85.222.65]:39590 "EHLO mail-ua1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727723AbfAKHbC (ORCPT ); Fri, 11 Jan 2019 02:31:02 -0500 Received: by mail-ua1-f65.google.com with SMTP id c12so4463554uas.6 for ; Thu, 10 Jan 2019 23:31:01 -0800 (PST) MIME-Version: 1.0 References: <1547123097-16431-1-git-send-email-sumit.garg@linaro.org> <1547123097-16431-4-git-send-email-sumit.garg@linaro.org> <20190110142355.bcgw62w2qk2mlzj6@holly.lan> In-Reply-To: <20190110142355.bcgw62w2qk2mlzj6@holly.lan> From: Sumit Garg Date: Fri, 11 Jan 2019 13:00:49 +0530 Message-ID: Subject: Re: [PATCH v2 3/4] tee: add supp_nowait flag in tee_context struct To: Daniel Thompson Cc: linux-arm-kernel@lists.infradead.org, "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , linux-kernel@vger.kernel.org, Jens Wiklander , mpm@selenic.com, Herbert Xu , Rob Herring , Mark Rutland , Arnd Bergmann , Greg Kroah-Hartman , Ard Biesheuvel , Bhupesh Sharma , tee-dev@lists.linaro.org Content-Type: text/plain; charset="UTF-8" Sender: linux-crypto-owner@vger.kernel.org List-ID: On Thu, 10 Jan 2019 at 19:53, Daniel Thompson wrote: > > On Thu, Jan 10, 2019 at 05:54:56PM +0530, Sumit Garg wrote: > > 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. > > This patch seems out of order in the patch set: Doesn't > optee_enumarate_devices() require this feature if it is to > work correctly with a TEE that does not implement the enumeate pTA. > > If so better to implement the feature first so that > optee_emumerate_devices() works correctly when it first appears. > Agree, will make this patch as #2 in next version. > > > > Signed-off-by: Sumit Garg > > --- > > drivers/tee/optee/supp.c | 10 +++++++++- > > drivers/tee/tee_core.c | 2 ++ > > include/linux/tee_drv.h | 6 ++++++ > > 3 files changed, 17 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c > > index 43626e1..92f56b8 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 9ddb89e..5d6c317 100644 > > --- a/drivers/tee/tee_core.c > > +++ b/drivers/tee/tee_core.c > > @@ -105,6 +105,7 @@ static int tee_open(struct inode *inode, struct file *filp) > > if (IS_ERR(ctx)) > > return PTR_ERR(ctx); > > > > + ctx->supp_nowait = false; > > filp->private_data = ctx; > > return 0; > > } > > @@ -981,6 +982,7 @@ tee_client_open_context(struct tee_context *start, > > } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM); > > > > put_device(put_dev); > > + ctx->supp_nowait = true; > > Why automatically set supp_nowait inside open_context() ? > I think this is the default behaviour (non-blocking request) that any in kernel client would expect. Also this flag could be configured again before call to open_session() if any in kernel client requires different behaviour. -Sumit > > > return ctx; > > } > > EXPORT_SYMBOL_GPL(tee_client_open_context); > > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h > > index ed16bf1..fe1a920 100644 > > --- a/include/linux/tee_drv.h > > +++ b/include/linux/tee_drv.h > > @@ -49,6 +49,11 @@ 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; > > @@ -56,6 +61,7 @@ struct tee_context { > > void *data; > > struct kref refcount; > > bool releasing; > > + bool supp_nowait; > > }; > > > > struct tee_param_memref { > > -- > > 2.7.4 > >