Messages in this thread | | | Date | Fri, 27 Jan 2023 12:19:02 +0100 | Subject | Re: [PATCH v2 1/1] tee: new ioctl to a register tee_shm from a dmabuf file descriptor | From | Christian König <> |
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Hi guys,
Am 27.01.23 um 11:54 schrieb Olivier Masse: > Hi Joakim, > Hi Etienne, > > Let me bring back this pull request for OPTEE Linux driver. > > Last feedback was from Christian König 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 ?
Just FYI: The upstream changes Dmitry worked on are now committed, so you just need to rebase your work on top and send it out once more.
>> 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.
That's not an issue. If you pin the memory anyway then you can expose it pinned through DMA-buf as well.
The only thing you should avoid is pinning it extra for DMA-buf, because then you often create a really nice possibility for an OOM deny of service.
Regards, Christian.
> > 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 pages. > 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. > > Best regards, > Olivier MASSE > > > On ven., 2022-08-12 at 16:30 +0200, Olivier Masse wrote: >> From: Etienne Carriere <etienne.carriere@linaro.org> >> >> 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 <etienne.carriere@linaro.org> >> Signed-off-by: Olivier Masse <olivier.masse@nxp.com> >> Reported-by: kernel test robot <lkp@intel.com> >> From: https://github.com/linaro-swg/linux.git >> (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 = 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 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 <linux/anon_inodes.h> >> #include <linux/device.h> >> +#include <linux/dma-buf.h> >> #include <linux/idr.h> >> #include <linux/mm.h> >> #include <linux/sched.h> >> @@ -12,6 +13,14 @@ >> #include <linux/uio.h> >> #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 = 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 = 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 = 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->dmabuf = dma_buf_get(fd); >> + if (IS_ERR(ref->dmabuf)) { >> + rc = PTR_ERR(ref->dmabuf); >> + goto err_put_dmabuf; >> + } >> + >> + ref->attach = dma_buf_attach(ref->dmabuf, &ref->shm.ctx- >>> teedev->dev); >> + if (IS_ERR(ref->attach)) { >> + rc = PTR_ERR(ref->attach); >> + goto err_detach; >> + } >> + >> + ref->sgt = dma_buf_map_attachment(ref->attach, >> DMA_BIDIRECTIONAL); >> + if (IS_ERR(ref->sgt)) { >> + rc = PTR_ERR(ref->sgt); >> + goto err_unmap_attachement; >> + } >> + >> + if (sg_nents(ref->sgt->sgl) != 1) { >> + rc = PTR_ERR(ref->sgt->sgl); >> + goto err_unmap_attachement; >> + } >> + >> + ref->shm.paddr = sg_dma_address(ref->sgt->sgl); >> + ref->shm.size = sg_dma_len(ref->sgt->sgl); >> + ref->shm.flags = TEE_SHM_EXT_DMA_BUF; >> + >> + 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_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
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