Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04DA7C636D4 for ; Thu, 2 Feb 2023 08:35:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229640AbjBBIf4 (ORCPT ); Thu, 2 Feb 2023 03:35:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232300AbjBBIfq (ORCPT ); Thu, 2 Feb 2023 03:35:46 -0500 Received: from mail-vs1-xe2e.google.com (mail-vs1-xe2e.google.com [IPv6:2607:f8b0:4864:20::e2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D153488CC0 for ; Thu, 2 Feb 2023 00:35:19 -0800 (PST) Received: by mail-vs1-xe2e.google.com with SMTP id h19so1028376vsv.13 for ; Thu, 02 Feb 2023 00:35:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=7eaFgR9EX7Id8t2x3MDKSgvpIl2QXj/cK0tw936ajZA=; b=HKCixygKqT7U6s09TmA4qDotBS/iVao2wP831bljrk8iQSKMKW6rL3gTg/WpK6qmPC Q2S1wm5wGIxkAuIJz16/Z7eAgsqjXOPFL/jiVZXzN5kJwNQbkYl50j+75pC1htNk+poD sGzVvIC0xdLvzmMvZ239mKy5//cQrGHrlsFp+VAc+ClOvUePzZjVSnJQ1DqMLDbZ1P5r aFHDmMRU5tLK8760x47pwVJlpxgRKGzFMK/rtP0cxroXgUdAaVFIy2Szc+8E3vES0NIH lAc/1xso9CSOPVnIFWL3Q1e77dWReCwjG3nd0Ud3S5yS1wPd1a/e1ACQ7qnofIaAUxaI /QMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=7eaFgR9EX7Id8t2x3MDKSgvpIl2QXj/cK0tw936ajZA=; b=7OSTLw82HOdZeiheg5PqEYjeA427FjFmEeqIbYTEIxEapu9iQBxSa1+17SpW8Ef08p mpofyqGknRpfR2cawsNloYfOzhwc3Zvd7QcPv3xLrelTft1yHZeFxxw0opUik4Zd8jMD bueYNjeCGTqHajdJuL2nFMPW7rpklWgvRO5qQw+fs+dDQTUtVimBYaSwc2/OUr6z30GO 9F1JRBiJhE5TJqB8PFBHIpF39gs2oTemGhV4h9Mvk1ZNlqr81CATbuhgJBuEc6cZhWzn yqXRkv6R5LHJvOw03sG6FX6yA8WWAvG8xq97vFLEGTVT43QwVefQDjU3nswptb+cNquJ 1vEw== X-Gm-Message-State: AO0yUKUyieB3KvXCwmPYVFBHJndKzm6w94E1fsdpYwry66ocqESEUDEB j2ozsdxlgZs3lJlLZBePWnjnVr2iLkkU1oVbojOhzA== X-Google-Smtp-Source: AK7set/pzc3Hdl4iFGY79IJBRXBPHqHMi3/AS9oVbeAkLXTlbQVlDpoXYhNcMvyQc5Iz3ZjzOtlEL+QjU2+LjqHTQNc= X-Received: by 2002:a05:6102:2378:b0:3ce:8835:de03 with SMTP id o24-20020a056102237800b003ce8835de03mr907847vsa.50.1675326918445; Thu, 02 Feb 2023 00:35:18 -0800 (PST) MIME-Version: 1.0 References: <20220812143055.12938-1-olivier.masse@nxp.com> <20220812143055.12938-2-olivier.masse@nxp.com> <30534fadb8172088eddef46ae71d87c167cbf32e.camel@nxp.com> In-Reply-To: From: Sumit Garg Date: Thu, 2 Feb 2023 14:05:07 +0530 Message-ID: Subject: Re: [EXT] Re: [PATCH v2 1/1] tee: new ioctl to a register tee_shm from a dmabuf file descriptor To: Cyrille Fleury Cc: Olivier Masse , "fredgc@google.com" , "linux-media@vger.kernel.org" , "linaro-mm-sig@lists.linaro.org" , "afd@ti.com" , "op-tee@lists.trustedfirmware.org" , "jens.wiklander@linaro.org" , "joakim.bech@linaro.org" , "sumit.semwal@linaro.org" , Peter Griffin , "linux-kernel@vger.kernel.org" , "etienne.carriere@linaro.org" , "dri-devel@lists.freedesktop.org" , "christian.koenig@amd.com" , =?UTF-8?Q?Cl=C3=A9ment_Faure?= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Cyrille, Please don't top post as it makes it harder to follow-up. On Thu, 2 Feb 2023 at 13:26, Cyrille Fleury wrote: > > Hi Sumit, all > > Upstream OP-TEE should support registering a dmabuf since a while, given = how widely dmabuf is used in Linux for passing buffers around between devic= es. > > Purpose of the new register_tee_shm ioctl is to allow OPTEE to use memory= allocated from the exiting linux dma buffer. We don't need to have secure = dma-heap up streamed. > > You mentioned secure dma-buffer, but secure dma-buffer is a dma-buffer, s= o the work to be done for secure or "regular" dma buffers by the register_t= ee_shm ioctl is 100% the same. > > The scope of this ioctl is limited to what existing upstream dma-buffers = are: > -> sharing buffers for hardware (DMA) access across multiple devi= ce drivers and subsystems, and for synchronizing asynchronous hardware acce= ss. > -> It means continuous memory only. > > So if we reduce the scope of register tee_shm to exiting dma-buffer area,= the current patch does the job. Do you have a corresponding real world use-case supported by upstream OP-TEE? AFAIK, the Secure Data Path (SDP) use-case is the one supported in OP-TEE upstream but without secure dmabuf heap [1] available, the new ioctl can't be exercised. [1] https://github.com/OP-TEE/optee_test/blob/master/host/xtest/sdp_basic.h= #L15 -Sumit > > Regards. > > -----Original Message----- > From: Sumit Garg > Sent: Wednesday, February 1, 2023 6:34 AM > To: Olivier Masse > Cc: fredgc@google.com; linux-media@vger.kernel.org; linaro-mm-sig@lists.l= inaro.org; afd@ti.com; op-tee@lists.trustedfirmware.org; jens.wiklander@lin= aro.org; joakim.bech@linaro.org; sumit.semwal@linaro.org; Peter Griffin ; linux-kernel@vger.kernel.org; etienne.carriere@lin= aro.org; dri-devel@lists.freedesktop.org; christian.koenig@amd.com; Cl=C3= =A9ment Faure ; Cyrille Fleury > Subject: [EXT] Re: [PATCH v2 1/1] tee: new ioctl to a register tee_shm fr= om a dmabuf file descriptor > > Caution: EXT Email > > Hi Olivier, > > On Fri, 27 Jan 2023 at 16:24, Olivier Masse wrote= : > > > > Hi Joakim, > > Hi Etienne, > > > > Let me bring back this pull request for OPTEE Linux driver. > > > > Last feedback was from Christian K=C3=B6nig and Sumit Garg. > > From Christian: > > > Just two comments: > > > > > > 1. Dmitry is working on a change which renames some functions and > > > makes it mandatory to call them with the dma_resv lock held. > > > > > > Depending on how you want to upstream this change you will certainly > > > run into conflicts with that. > > > > Is there any update on these changes ? > > > > > > > > 2. Would it be possible to do this dynamically? In other words does > > > the tee driver has a concept of buffers moving around? > > > > We do not support dynamic secure memory heap. > > > > From Sumit: > > > What limits you to extend this feature to non-contiguous memory > > > buffers? I believe that should be possible with OP-TEE dynamic > > > shared memory which gives you the granularity to register a list of p= ages. > > > > Our solution use a fixed protected reserved memory region and do not > > rely on a dynamic protection managed in secure. > > > > The scope of this implementation rely on a static memory region > > handled by a specific DMA Heap type. > > > > AFAIR, the last review for v2 is here [1]. So we need to have this secure= DMA heap upstream in order for ioctl added by this patch to be usable. > > [1] https://eur01.safelinks.protection.outlook.com/?url=3Dhttps%3A%2F%2Fl= ists.trustedfirmware.org%2Farchives%2Flist%2Fop-tee%40lists.trustedfirmware= .org%2Fmessage%2FM3WLO7RNG22OR4744BY6XNG2GLIYMNHN%2F&data=3D05%7C01%7Ccyril= le.fleury%40nxp.com%7Cb24461a4e7284314dff408db0415f23e%7C686ea1d3bc2b4c6fa9= 2cd99c5c301635%7C0%7C0%7C638108264533221384%7CUnknown%7CTWFpbGZsb3d8eyJWIjo= iMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C= &sdata=3D6pRAqnMlJ0TX000YmlgTkPKn411VBC%2Bj29O9KhJjJOg%3D&reserved=3D0 > > -Sumit > > > Best regards, > > Olivier MASSE > > > > > > On ven., 2022-08-12 at 16:30 +0200, Olivier Masse wrote: > > > From: Etienne Carriere > > > > > > This change allows userland to create a tee_shm object that refers > > > to a dmabuf reference. > > > > > > Userland provides a dmabuf file descriptor as buffer reference. > > > The created tee_shm object exported as a brand new dmabuf reference > > > used to provide a clean fd to userland. Userland shall closed this > > > new fd to release the tee_shm object resources. The initial dmabuf > > > resources are tracked independently through original dmabuf file > > > descriptor. > > > > > > Once the buffer is registered and until it is released, TEE driver > > > keeps a refcount on the registered dmabuf structure. > > > > > > This change only support dmabuf references that relates to > > > physically contiguous memory buffers. > > > > > > New tee_shm flag to identify tee_shm objects built from a registered > > > dmabuf: TEE_SHM_EXT_DMA_BUF. Such tee_shm structures are flagged > > > with TEE_SHM_EXT_DMA_BUF. > > > > > > Co-Developed-by: Etienne Carriere > > > Signed-off-by: Olivier Masse > > > Reported-by: kernel test robot > > > From: > > > https://eur01.safelinks.protection.outlook.com/?url=3Dhttps%3A%2F%2Fg= i > > > thub.com%2Flinaro-swg%2Flinux.git&data=3D05%7C01%7Ccyrille.fleury%40n= x > > > p.com%7Cb24461a4e7284314dff408db0415f23e%7C686ea1d3bc2b4c6fa92cd99c5 > > > c301635%7C0%7C0%7C638108264533221384%7CUnknown%7CTWFpbGZsb3d8eyJWIjo > > > iMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7 > > > C%7C%7C&sdata=3D8jbFPaF%2B5JBed4Uvo1hsJiB%2BP71KUgJmnW%2BIi3zLfok%3D&= r > > > eserved=3D0 (cherry picked from commit > > > 41e21e5c405530590dc2dd10b2a8dbe64589840f) > > > --- > > > drivers/tee/tee_core.c | 38 +++++++++++++++ > > > drivers/tee/tee_shm.c | 99 > > > +++++++++++++++++++++++++++++++++++++++- > > > include/linux/tee_drv.h | 11 +++++ include/uapi/linux/tee.h | 29 > > > ++++++++++++ > > > 4 files changed, 175 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index > > > 8aa1a4836b92..7c45cbf85eb9 100644 > > > --- a/drivers/tee/tee_core.c > > > +++ b/drivers/tee/tee_core.c > > > @@ -355,6 +355,42 @@ tee_ioctl_shm_register(struct tee_context *ctx, > > > return ret; > > > } > > > > > > +static int tee_ioctl_shm_register_fd(struct tee_context *ctx, > > > + struct > > > tee_ioctl_shm_register_fd_data __user *udata) > > > +{ > > > + struct tee_ioctl_shm_register_fd_data data; > > > + struct tee_shm *shm; > > > + long ret; > > > + > > > + if (copy_from_user(&data, udata, sizeof(data))) > > > + return -EFAULT; > > > + > > > + /* Currently no input flags are supported */ > > > + if (data.flags) > > > + return -EINVAL; > > > + > > > + shm =3D tee_shm_register_fd(ctx, data.fd); > > > + if (IS_ERR(shm)) > > > + return -EINVAL; > > > + > > > + data.id =3D shm->id; > > > + data.flags =3D shm->flags; > > > + data.size =3D shm->size; > > > + > > > + if (copy_to_user(udata, &data, sizeof(data))) > > > + ret =3D -EFAULT; > > > + else > > > + ret =3D tee_shm_get_fd(shm); > > > + > > > + /* > > > + * When user space closes the file descriptor the shared memory > > > + * should be freed or if tee_shm_get_fd() failed then it will > > > + * be freed immediately. > > > + */ > > > + tee_shm_put(shm); > > > + return ret; > > > +} > > > + > > > static int params_from_user(struct tee_context *ctx, struct > > > tee_param *params, > > > size_t num_params, > > > struct tee_ioctl_param __user *uparams) @@ > > > -829,6 +865,8 @@ static long tee_ioctl(struct file *filp, unsigned > > > int cmd, unsigned long arg) > > > return tee_ioctl_shm_alloc(ctx, uarg); > > > case TEE_IOC_SHM_REGISTER: > > > return tee_ioctl_shm_register(ctx, uarg); > > > + case TEE_IOC_SHM_REGISTER_FD: > > > + return tee_ioctl_shm_register_fd(ctx, uarg); > > > case TEE_IOC_OPEN_SESSION: > > > return tee_ioctl_open_session(ctx, uarg); > > > case TEE_IOC_INVOKE: > > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index > > > 836872467dc6..55a3fbbb022e 100644 > > > --- a/drivers/tee/tee_shm.c > > > +++ b/drivers/tee/tee_shm.c > > > @@ -4,6 +4,7 @@ > > > */ > > > #include > > > #include > > > +#include > > > #include > > > #include > > > #include > > > @@ -12,6 +13,14 @@ > > > #include > > > #include "tee_private.h" > > > > > > +/* extra references appended to shm object for registered shared > > > memory */ > > > +struct tee_shm_dmabuf_ref { > > > + struct tee_shm shm; > > > + struct dma_buf *dmabuf; > > > + struct dma_buf_attachment *attach; > > > + struct sg_table *sgt; > > > +}; > > > + > > > static void shm_put_kernel_pages(struct page **pages, size_t > > > page_count) > > > { > > > size_t n; > > > @@ -71,7 +80,16 @@ static void release_registered_pages(struct > > > tee_shm *shm) > > > > > > static void tee_shm_release(struct tee_device *teedev, struct > > > tee_shm *shm) { > > > - if (shm->flags & TEE_SHM_POOL) { > > > + if (shm->flags & TEE_SHM_EXT_DMA_BUF) { > > > + struct tee_shm_dmabuf_ref *ref; > > > + > > > + ref =3D container_of(shm, struct tee_shm_dmabuf_ref, > > > shm); > > > + dma_buf_unmap_attachment(ref->attach, ref->sgt, > > > + DMA_BIDIRECTIONAL); > > > + > > > + dma_buf_detach(ref->dmabuf, ref->attach); > > > + dma_buf_put(ref->dmabuf); > > > + } else if (shm->flags & TEE_SHM_POOL) { > > > teedev->pool->ops->free(teedev->pool, shm); > > > } else if (shm->flags & TEE_SHM_DYNAMIC) { > > > int rc =3D teedev->desc->ops->shm_unregister(shm->ctx, > > > shm); > > > @@ -195,7 +213,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct > > > tee_context *ctx, size_t size) > > > * tee_client_invoke_func(). The memory allocated is later freed > > > with a > > > * call to tee_shm_free(). > > > * > > > - * @returns a pointer to 'struct tee_shm' > > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR > > > + on > > > failure > > > */ > > > struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, > > > size_t size) { @@ -229,6 +247,83 @@ struct tee_shm > > > *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) } > > > EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); > > > > > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int > > > +fd) { > > > + struct tee_shm_dmabuf_ref *ref; > > > + int rc; > > > + > > > + if (!tee_device_get(ctx->teedev)) > > > + return ERR_PTR(-EINVAL); > > > + > > > + teedev_ctx_get(ctx); > > > + > > > + ref =3D kzalloc(sizeof(*ref), GFP_KERNEL); > > > + if (!ref) { > > > + rc =3D -ENOMEM; > > > + goto err_put_tee; > > > + } > > > + > > > + refcount_set(&ref->shm.refcount, 1); > > > + ref->shm.ctx =3D ctx; > > > + ref->shm.id =3D -1; > > > + > > > + ref->dmabuf =3D dma_buf_get(fd); > > > + if (IS_ERR(ref->dmabuf)) { > > > + rc =3D PTR_ERR(ref->dmabuf); > > > + goto err_put_dmabuf; > > > + } > > > + > > > + ref->attach =3D dma_buf_attach(ref->dmabuf, &ref->shm.ctx- > > > >teedev->dev); > > > + if (IS_ERR(ref->attach)) { > > > + rc =3D PTR_ERR(ref->attach); > > > + goto err_detach; > > > + } > > > + > > > + ref->sgt =3D dma_buf_map_attachment(ref->attach, > > > DMA_BIDIRECTIONAL); > > > + if (IS_ERR(ref->sgt)) { > > > + rc =3D PTR_ERR(ref->sgt); > > > + goto err_unmap_attachement; > > > + } > > > + > > > + if (sg_nents(ref->sgt->sgl) !=3D 1) { > > > + rc =3D PTR_ERR(ref->sgt->sgl); > > > + goto err_unmap_attachement; > > > + } > > > + > > > + ref->shm.paddr =3D sg_dma_address(ref->sgt->sgl); > > > + ref->shm.size =3D sg_dma_len(ref->sgt->sgl); > > > + ref->shm.flags =3D TEE_SHM_EXT_DMA_BUF; > > > + > > > + mutex_lock(&ref->shm.ctx->teedev->mutex); > > > + ref->shm.id =3D idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm= , > > > + 1, 0, GFP_KERNEL); > > > + mutex_unlock(&ref->shm.ctx->teedev->mutex); > > > + if (ref->shm.id < 0) { > > > + rc =3D ref->shm.id; > > > + goto err_idr_remove; > > > + } > > > + > > > + return &ref->shm; > > > + > > > +err_idr_remove: > > > + mutex_lock(&ctx->teedev->mutex); > > > + idr_remove(&ctx->teedev->idr, ref->shm.id); > > > + mutex_unlock(&ctx->teedev->mutex); > > > +err_unmap_attachement: > > > + dma_buf_unmap_attachment(ref->attach, ref->sgt, > > > DMA_BIDIRECTIONAL); > > > +err_detach: > > > + dma_buf_detach(ref->dmabuf, ref->attach); > > > +err_put_dmabuf: > > > + dma_buf_put(ref->dmabuf); > > > + kfree(ref); > > > +err_put_tee: > > > + teedev_ctx_put(ctx); > > > + tee_device_put(ctx->teedev); > > > + > > > + return ERR_PTR(rc); > > > +} > > > +EXPORT_SYMBOL_GPL(tee_shm_register_fd); > > > + > > > static struct tee_shm * > > > register_shm_helper(struct tee_context *ctx, unsigned long addr, > > > size_t length, u32 flags, int id) diff --git > > > a/include/linux/tee_drv.h b/include/linux/tee_drv.h index > > > 911cad324acc..40ddd5376c2d 100644 > > > --- a/include/linux/tee_drv.h > > > +++ b/include/linux/tee_drv.h > > > @@ -25,6 +25,7 @@ > > > #define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user space > > > */ > > > #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool > > > */ > > > #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver > > > */ > > > +#define TEE_SHM_EXT_DMA_BUF BIT(4) /* Memory with dma-buf > > > handle */ > > > > > > struct device; > > > struct tee_device; > > > @@ -276,6 +277,16 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct > > > tee_context *ctx, size_t size); struct tee_shm > > > *tee_shm_register_kernel_buf(struct tee_context *ctx, > > > void *addr, size_t > > > length); > > > > > > +/** > > > + * tee_shm_register_fd() - Register shared memory from file > > > descriptor > > > + * > > > + * @ctx: Context that allocates the shared memory > > > + * @fd: Shared memory file descriptor reference > > > + * > > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR > > > + on > > > failure > > > + */ > > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int > > > fd); > > > + > > > /** > > > * tee_shm_is_dynamic() - Check if shared memory object is of the > > > dynamic kind > > > * @shm: Shared memory handle > > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h > > > index 25a6c534beb1..baf3cd7cfdac 100644 > > > --- a/include/uapi/linux/tee.h > > > +++ b/include/uapi/linux/tee.h > > > @@ -121,6 +121,35 @@ struct tee_ioctl_shm_alloc_data { > > > #define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, > > > \ > > > struct tee_ioctl_shm_alloc_data) > > > > > > +/** > > > + * struct tee_ioctl_shm_register_fd_data - Shared memory > > > +registering > > > argument > > > + * @fd: [in] File descriptor identifying the shared > > > memory > > > + * @size: [out] Size of shared memory to allocate > > > + * @flags: [in] Flags to/from allocation. > > > + * @id: [out] Identifier of the shared memory > > > + * > > > + * The flags field should currently be zero as input. Updated by > > > + the > > > call > > > + * with actual flags as defined by TEE_IOCTL_SHM_* above. > > > + * This structure is used as argument for TEE_IOC_SHM_REGISTER_FD > > > below. > > > + */ > > > +struct tee_ioctl_shm_register_fd_data { > > > + __s64 fd; > > > + __u64 size; > > > + __u32 flags; > > > + __s32 id; > > > +} __attribute__ ((aligned (8))); > > > + > > > +/** > > > + * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file > > > descriptor > > > + * > > > + * Returns a file descriptor on success or < 0 on failure > > > + * > > > + * The returned file descriptor refers to the shared memory object > > > in kernel > > > + * land. The shared memory is freed when the descriptor is closed. > > > + */ > > > +#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, > > > TEE_IOC_BASE + 8, \ > > > + struct > > > tee_ioctl_shm_register_fd_data) > > > + > > > /** > > > * struct tee_ioctl_buf_data - Variable sized buffer > > > * @buf_ptr: [in] A __user pointer to a buffer