From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E58BBCA0EDC for ; Thu, 14 Aug 2025 06:06:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=kAFtjuQI+xX4dUqhz6/TPBLkP9xmrSCy8eEI6rkYbzQ=; b=LePw6KDvP0QP8gnGE8nF0glFe2 bmjSPvW9y72+3OquT8WP6BbfVfgbIOuTzKMj7Zh8YUehRcSY5i+K7X+TmquPLyMM5wFc9e+ImzOyV 7JL9Kv5yE2qFqRJRsNqwH4ZR4rnePDjR/IqOvwU0SQX9UslHxXzEqoPznpoEKjDfuIGIip6bYKyVa ZhWi/aVwlzoZDOUSTUAtGekv/2Cd7q3G+N4pbhiSuonOQ3lu9YSm6Y5Gy62IOrAh+vMiISu7HL9uZ ZMMdSmHcQOCZpRggt1Agj9YHFzAl50kv0vdWyY2UXig/dMuPS5+uTRpgN4AwrQokw10sjqkNll9IL t2ZeO70Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1umR6C-0000000Ftyp-2onc; Thu, 14 Aug 2025 06:06:04 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1umR3b-0000000Fteo-3nfM for linux-arm-kernel@lists.infradead.org; Thu, 14 Aug 2025 06:03:25 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 9E3AFA4F072; Thu, 14 Aug 2025 06:03:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0DC5C4CEEF; Thu, 14 Aug 2025 06:03:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755151402; bh=8EKk4Xw7VwzxxEJxQKhC4NtiY9g+vxyPs5oc5M5f27E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oXcIRmbmH611HxPBJ16ayYXCwh/f3OX6xihUMZUY5BxoJM/BAHDUwtGS8uff5vakB SgxhZMyh+cRuZep0oKfMc3HbFd93ucJU0hT+7HvF35U7RaGve9idaQUHxeF+rXC0fb cP6IK3PK9KYBiNqVacCqSVmMcxk5YtkDUxqvsQXKCFnLivc6MNzg0cFF5cqp+XvmjZ kXyWQ7hGmYufk5Wirp/sPdsWvbxXSUwPfry7NXRzZyaJMNG9Vxv4QN+/nt+3xc4o+e fu3pawPjzQXhlVTsNJqHEvqvfRMQZ4rP2kkU9XEOanb5sSH/QLQFtN5/unRrZWeVfo fhqJ6XQWXjx0g== Date: Thu, 14 Aug 2025 11:32:58 +0530 From: Sumit Garg To: Jens Wiklander Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, op-tee@lists.trustedfirmware.org, linux-arm-kernel@lists.infradead.org, Olivier Masse , Thierry Reding , Yong Wu , Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T . J . Mercier" , Christian =?iso-8859-1?Q?K=F6nig?= , Matthias Brugger , AngeloGioacchino Del Regno , azarrabi@qti.qualcomm.com, Simona Vetter , Daniel Stone , Rouven Czerwinski , robin.murphy@arm.com, Etienne Carriere Subject: Re: [PATCH v11 5/9] tee: new ioctl to a register tee_shm from a dmabuf file descriptor Message-ID: References: <20250813060339.2977604-1-jens.wiklander@linaro.org> <20250813060339.2977604-6-jens.wiklander@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250813060339.2977604-6-jens.wiklander@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250813_230324_099661_E07AE11B X-CRM114-Status: GOOD ( 48.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Aug 13, 2025 at 08:02:54AM +0200, Jens Wiklander wrote: > From: Etienne Carriere > > Add a userspace API to create a tee_shm object that refers to a dmabuf > reference. > > Userspace registers the dmabuf file descriptor as in a tee_shm object. > The registration is completed with a tee_shm returned file descriptor. > > Userspace is free to close the dmabuf file descriptor after it has been > registered since all the resources are now held via the new tee_shm > object. > > Closing the tee_shm file descriptor will eventually release all > resources used by the tee_shm object when all references are released. > > The new IOCTL, TEE_IOC_SHM_REGISTER_FD, supports dmabuf references to > physically contiguous memory buffers. Dmabuf references acquired from > the TEE DMA-heap can be used as protected memory for Secure Video Path > and such use cases. It depends on the TEE and the TEE driver if dmabuf > references acquired by other means can be used. > > A new tee_shm flag is added to identify tee_shm objects built from a > registered dmabuf, TEE_SHM_DMA_BUF. > > Signed-off-by: Etienne Carriere > Signed-off-by: Olivier Masse > Signed-off-by: Jens Wiklander > --- > drivers/tee/tee_core.c | 63 ++++++++++++++++++++++++++++++++- > drivers/tee/tee_private.h | 8 +++++ > drivers/tee/tee_shm.c | 74 +++++++++++++++++++++++++++++++++++++-- > include/linux/tee_core.h | 1 + > include/linux/tee_drv.h | 10 ++++++ > include/uapi/linux/tee.h | 31 ++++++++++++++++ > 6 files changed, 183 insertions(+), 4 deletions(-) Reviewed-by: Sumit Garg -Sumit > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c > index b89f93b1f8f2..fe414595fc2c 100644 > --- a/drivers/tee/tee_core.c > +++ b/drivers/tee/tee_core.c > @@ -354,11 +354,49 @@ 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 = tee_shm_register_fd(ctx, data.fd); > + if (IS_ERR(shm)) > + return -EINVAL; > + > + data.id = shm->id; > + data.flags = shm->flags; > + data.size = shm->size; > + > + if (copy_to_user(udata, &data, sizeof(data))) > + ret = -EFAULT; > + else > + ret = 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 param_from_user_memref(struct tee_context *ctx, > struct tee_param_memref *memref, > struct tee_ioctl_param *ip) > { > struct tee_shm *shm; > + size_t offs = 0; > > /* > * If a NULL pointer is passed to a TA in the TEE, > @@ -389,6 +427,26 @@ static int param_from_user_memref(struct tee_context *ctx, > tee_shm_put(shm); > return -EINVAL; > } > + > + if (shm->flags & TEE_SHM_DMA_BUF) { > + struct tee_shm_dmabuf_ref *ref; > + > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm); > + if (ref->parent_shm) { > + /* > + * The shm already has one reference to > + * ref->parent_shm so we are clear of 0. > + * We're getting another reference since > + * this shm will be used in the parameter > + * list instead of the shm we got with > + * tee_shm_get_from_id() above. > + */ > + refcount_inc(&ref->parent_shm->refcount); > + tee_shm_put(shm); > + shm = ref->parent_shm; > + offs = ref->offset; > + } > + } > } else if (ctx->cap_memref_null) { > /* Pass NULL pointer to OP-TEE */ > shm = NULL; > @@ -396,7 +454,7 @@ static int param_from_user_memref(struct tee_context *ctx, > return -EINVAL; > } > > - memref->shm_offs = ip->a; > + memref->shm_offs = ip->a + offs; > memref->size = ip->b; > memref->shm = shm; > > @@ -842,6 +900,8 @@ 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: > @@ -1303,3 +1363,4 @@ MODULE_AUTHOR("Linaro"); > MODULE_DESCRIPTION("TEE Driver"); > MODULE_VERSION("1.0"); > MODULE_LICENSE("GPL v2"); > +MODULE_IMPORT_NS("DMA_BUF"); > diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h > index 6c6ff5d5eed2..a9b5e4a6a8f7 100644 > --- a/drivers/tee/tee_private.h > +++ b/drivers/tee/tee_private.h > @@ -13,6 +13,14 @@ > #include > #include > > +/* extra references appended to shm object for registered shared memory */ > +struct tee_shm_dmabuf_ref { > + struct tee_shm shm; > + size_t offset; > + struct dma_buf *dmabuf; > + struct tee_shm *parent_shm; > +}; > + > int tee_shm_get_fd(struct tee_shm *shm); > > bool tee_device_get(struct tee_device *teedev); > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c > index daf6e5cfd59a..76195a398c89 100644 > --- a/drivers/tee/tee_shm.c > +++ b/drivers/tee/tee_shm.c > @@ -4,6 +4,7 @@ > */ > #include > #include > +#include > #include > #include > #include > @@ -45,7 +46,15 @@ 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) { > + void *p = shm; > + > + if (shm->flags & TEE_SHM_DMA_BUF) { > + struct tee_shm_dmabuf_ref *ref; > + > + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm); > + p = ref; > + 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 = teedev->desc->ops->shm_unregister(shm->ctx, shm); > @@ -59,7 +68,7 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) > > teedev_ctx_put(shm->ctx); > > - kfree(shm); > + kfree(p); > > tee_device_put(teedev); > } > @@ -169,7 +178,7 @@ 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) > { > @@ -179,6 +188,62 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size) > } > EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_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 = kzalloc(sizeof(*ref), GFP_KERNEL); > + if (!ref) { > + rc = -ENOMEM; > + goto err_put_tee; > + } > + > + refcount_set(&ref->shm.refcount, 1); > + ref->shm.ctx = ctx; > + ref->shm.id = -1; > + ref->shm.flags = TEE_SHM_DMA_BUF; > + > + ref->dmabuf = dma_buf_get(fd); > + if (IS_ERR(ref->dmabuf)) { > + rc = PTR_ERR(ref->dmabuf); > + goto err_kfree_ref; > + } > + > + rc = tee_heap_update_from_dma_buf(ctx->teedev, ref->dmabuf, > + &ref->offset, &ref->shm, > + &ref->parent_shm); > + if (rc) > + goto err_put_dmabuf; > + > + mutex_lock(&ref->shm.ctx->teedev->mutex); > + ref->shm.id = 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 = ref->shm.id; > + goto err_put_dmabuf; > + } > + > + return &ref->shm; > + > +err_put_dmabuf: > + dma_buf_put(ref->dmabuf); > +err_kfree_ref: > + 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); > + > /** > * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared > * kernel buffer > @@ -442,6 +507,9 @@ static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma) > /* Refuse sharing shared memory provided by application */ > if (shm->flags & TEE_SHM_USER_MAPPED) > return -EINVAL; > + /* Refuse sharing registered DMA_bufs with the application */ > + if (shm->flags & TEE_SHM_DMA_BUF) > + return -EINVAL; > > /* check for overflowing the buffer's size */ > if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT) > diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h > index 28b65010b9ed..b6c54b34a8b5 100644 > --- a/include/linux/tee_core.h > +++ b/include/linux/tee_core.h > @@ -28,6 +28,7 @@ > #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_DMA_BUF BIT(4) /* Memory with dma-buf handle */ > > #define TEE_DEVICE_FLAG_REGISTERED 0x1 > #define TEE_MAX_DEV_NAME_LEN 32 > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h > index a54c203000ed..824f1251de60 100644 > --- a/include/linux/tee_drv.h > +++ b/include/linux/tee_drv.h > @@ -116,6 +116,16 @@ 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_free() - Free shared memory > * @shm: Handle to shared memory to free > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h > index d0430bee8292..d843cf980d98 100644 > --- a/include/uapi/linux/tee.h > +++ b/include/uapi/linux/tee.h > @@ -378,6 +378,37 @@ struct tee_ioctl_shm_register_data { > __s32 id; > }; > > +/** > + * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument > + * @fd: [in] File descriptor identifying dmabuf reference > + * @size: [out] Size of referenced memory > + * @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; > +}; > + > +/** > + * 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 the > + * kernel. The supplied file deccriptor can be closed if it's not needed > + * for other purposes. 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) > + > /** > * TEE_IOC_SHM_REGISTER - Register shared memory argument > * > -- > 2.43.0 >