diff options
Diffstat (limited to 'drivers/tee/tee_shm.c')
| -rw-r--r-- | drivers/tee/tee_shm.c | 719 |
1 files changed, 719 insertions, 0 deletions
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c new file mode 100644 index 000000000..6742b3579 --- /dev/null +++ b/drivers/tee/tee_shm.c @@ -0,0 +1,719 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015-2017, 2019-2021 Linaro Limited + */ +#include <linux/anon_inodes.h> +#include <linux/device.h> +#include <linux/dma-buf.h> +#include <linux/dma-mapping.h> +#include <linux/highmem.h> +#include <linux/idr.h> +#include <linux/io.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/tee_core.h> +#include <linux/uaccess.h> +#include <linux/uio.h> +#include "tee_private.h" + +struct tee_shm_dma_mem { + struct tee_shm shm; + dma_addr_t dma_addr; + struct page *page; +}; + +static void release_registered_pages(struct tee_shm *shm) +{ + if (shm->pages) { + if (shm->flags & TEE_SHM_USER_MAPPED) + unpin_user_pages(shm->pages, shm->num_pages); + + kfree(shm->pages); + } +} + +static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) +{ + void *p = shm; + + if (shm->flags & TEE_SHM_DMA_MEM) { +#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS) + struct tee_shm_dma_mem *dma_mem; + + dma_mem = container_of(shm, struct tee_shm_dma_mem, shm); + p = dma_mem; + dma_free_pages(&teedev->dev, shm->size, dma_mem->page, + dma_mem->dma_addr, DMA_BIDIRECTIONAL); +#endif + } else 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); + + if (rc) + dev_err(teedev->dev.parent, + "unregister shm %p failed: %d", shm, rc); + + release_registered_pages(shm); + } + + teedev_ctx_put(shm->ctx); + + kfree(p); + + tee_device_put(teedev); +} + +static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size, + size_t align, u32 flags, int id) +{ + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + void *ret; + int rc; + + if (!tee_device_get(teedev)) + return ERR_PTR(-EINVAL); + + if (!teedev->pool) { + /* teedev has been detached from driver */ + ret = ERR_PTR(-EINVAL); + goto err_dev_put; + } + + shm = kzalloc_obj(*shm); + if (!shm) { + ret = ERR_PTR(-ENOMEM); + goto err_dev_put; + } + + refcount_set(&shm->refcount, 1); + shm->flags = flags; + shm->id = id; + + /* + * We're assigning this as it is needed if the shm is to be + * registered. If this function returns OK then the caller expected + * to call teedev_ctx_get() or clear shm->ctx in case it's not + * needed any longer. + */ + shm->ctx = ctx; + + rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align); + if (rc) { + ret = ERR_PTR(rc); + goto err_kfree; + } + + teedev_ctx_get(ctx); + return shm; +err_kfree: + kfree(shm); +err_dev_put: + tee_device_put(teedev); + return ret; +} + +/** + * tee_shm_alloc_user_buf() - Allocate shared memory for user space + * @ctx: Context that allocates the shared memory + * @size: Requested size of shared memory + * + * Memory allocated as user space shared memory is automatically freed when + * the TEE file pointer is closed. The primary usage of this function is + * when the TEE driver doesn't support registering ordinary user space + * memory. + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size) +{ + u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL; + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + void *ret; + int id; + + mutex_lock(&teedev->mutex); + id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL); + mutex_unlock(&teedev->mutex); + if (id < 0) + return ERR_PTR(id); + + shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id); + if (IS_ERR(shm)) { + mutex_lock(&teedev->mutex); + idr_remove(&teedev->idr, id); + mutex_unlock(&teedev->mutex); + return shm; + } + + mutex_lock(&teedev->mutex); + ret = idr_replace(&teedev->idr, shm, id); + mutex_unlock(&teedev->mutex); + if (IS_ERR(ret)) { + tee_shm_free(shm); + return ret; + } + + return shm; +} + +/** + * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer + * @ctx: Context that allocates the shared memory + * @size: Requested size of shared memory + * + * The returned memory registered in secure world and is suitable to be + * passed as a memory buffer in parameter argument to + * tee_client_invoke_func(). The memory allocated is later freed with a + * call to tee_shm_free(). + * + * @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) +{ + u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL; + + return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1); +} +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_obj(*ref); + 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 + * @ctx: Context that allocates the shared memory + * @size: Requested size of shared memory + * + * This function returns similar shared memory as + * tee_shm_alloc_kernel_buf(), but with the difference that the memory + * might not be registered in secure world in case the driver supports + * passing memory not registered in advance. + * + * This function should normally only be used internally in the TEE + * drivers. + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) +{ + u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL; + + return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); + +#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS) +/** + * tee_shm_alloc_dma_mem() - Allocate DMA memory as shared memory object + * @ctx: Context that allocates the shared memory + * @page_count: Number of pages + * + * The allocated memory is expected to be lent (made inaccessible to the + * kernel) to the TEE while it's used and returned (accessible to the + * kernel again) before it's freed. + * + * This function should normally only be used internally in the TEE + * drivers. + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx, + size_t page_count) +{ + struct tee_device *teedev = ctx->teedev; + struct tee_shm_dma_mem *dma_mem; + dma_addr_t dma_addr; + struct page *page; + + if (!tee_device_get(teedev)) + return ERR_PTR(-EINVAL); + + page = dma_alloc_pages(&teedev->dev, page_count * PAGE_SIZE, + &dma_addr, DMA_BIDIRECTIONAL, GFP_KERNEL); + if (!page) + goto err_put_teedev; + + dma_mem = kzalloc_obj(*dma_mem); + if (!dma_mem) + goto err_free_pages; + + refcount_set(&dma_mem->shm.refcount, 1); + dma_mem->shm.ctx = ctx; + dma_mem->shm.paddr = page_to_phys(page); + dma_mem->dma_addr = dma_addr; + dma_mem->page = page; + dma_mem->shm.size = page_count * PAGE_SIZE; + dma_mem->shm.flags = TEE_SHM_DMA_MEM; + + teedev_ctx_get(ctx); + + return &dma_mem->shm; + +err_free_pages: + dma_free_pages(&teedev->dev, page_count * PAGE_SIZE, page, dma_addr, + DMA_BIDIRECTIONAL); +err_put_teedev: + tee_device_put(teedev); + + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem); +#else +struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx, + size_t page_count) +{ + return ERR_PTR(-EINVAL); +} +EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem); +#endif + +int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align, + int (*shm_register)(struct tee_context *ctx, + struct tee_shm *shm, + struct page **pages, + size_t num_pages, + unsigned long start)) +{ + size_t nr_pages = roundup(size, PAGE_SIZE) / PAGE_SIZE; + struct page **pages; + unsigned int i; + int rc = 0; + + /* + * Ignore alignment since this is already going to be page aligned + * and there's no need for any larger alignment. + */ + shm->kaddr = alloc_pages_exact(nr_pages * PAGE_SIZE, + GFP_KERNEL | __GFP_ZERO); + if (!shm->kaddr) + return -ENOMEM; + + shm->paddr = virt_to_phys(shm->kaddr); + shm->size = nr_pages * PAGE_SIZE; + + pages = kzalloc_objs(*pages, nr_pages); + if (!pages) { + rc = -ENOMEM; + goto err_pages; + } + + for (i = 0; i < nr_pages; i++) + pages[i] = virt_to_page((u8 *)shm->kaddr + i * PAGE_SIZE); + + shm->pages = pages; + shm->num_pages = nr_pages; + + if (shm_register) { + rc = shm_register(shm->ctx, shm, pages, nr_pages, + (unsigned long)shm->kaddr); + if (rc) + goto err_kfree; + } + + return 0; +err_kfree: + kfree(pages); +err_pages: + free_pages_exact(shm->kaddr, shm->size); + shm->kaddr = NULL; + return rc; +} +EXPORT_SYMBOL_GPL(tee_dyn_shm_alloc_helper); + +void tee_dyn_shm_free_helper(struct tee_shm *shm, + int (*shm_unregister)(struct tee_context *ctx, + struct tee_shm *shm)) +{ + if (shm_unregister) + shm_unregister(shm->ctx, shm); + free_pages_exact(shm->kaddr, shm->size); + shm->kaddr = NULL; + kfree(shm->pages); + shm->pages = NULL; +} +EXPORT_SYMBOL_GPL(tee_dyn_shm_free_helper); + +static struct tee_shm * +register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags, + int id) +{ + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + unsigned long start, addr; + size_t num_pages, off; + ssize_t len; + void *ret; + int rc; + + if (!tee_device_get(teedev)) + return ERR_PTR(-EINVAL); + + if (!teedev->desc->ops->shm_register || + !teedev->desc->ops->shm_unregister) { + ret = ERR_PTR(-ENOTSUPP); + goto err_dev_put; + } + + teedev_ctx_get(ctx); + + shm = kzalloc_obj(*shm); + if (!shm) { + ret = ERR_PTR(-ENOMEM); + goto err_ctx_put; + } + + refcount_set(&shm->refcount, 1); + shm->flags = flags; + shm->ctx = ctx; + shm->id = id; + addr = untagged_addr((unsigned long)iter_iov_addr(iter)); + start = rounddown(addr, PAGE_SIZE); + num_pages = iov_iter_npages(iter, INT_MAX); + if (!num_pages) { + ret = ERR_PTR(-ENOMEM); + goto err_free_shm; + } + + shm->pages = kzalloc_objs(*shm->pages, num_pages); + if (!shm->pages) { + ret = ERR_PTR(-ENOMEM); + goto err_free_shm; + } + + len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0, + &off); + if (unlikely(len <= 0)) { + ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM); + goto err_free_shm_pages; + } else if (DIV_ROUND_UP(len + off, PAGE_SIZE) != num_pages) { + /* + * If we only got a few pages, update to release the + * correct amount below. + */ + shm->num_pages = len / PAGE_SIZE; + ret = ERR_PTR(-ENOMEM); + goto err_put_shm_pages; + } + + shm->offset = off; + shm->size = len; + shm->num_pages = num_pages; + + rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages, + shm->num_pages, start); + if (rc) { + ret = ERR_PTR(rc); + goto err_put_shm_pages; + } + + return shm; +err_put_shm_pages: + if (!iov_iter_is_kvec(iter)) + unpin_user_pages(shm->pages, shm->num_pages); +err_free_shm_pages: + kfree(shm->pages); +err_free_shm: + kfree(shm); +err_ctx_put: + teedev_ctx_put(ctx); +err_dev_put: + tee_device_put(teedev); + return ret; +} + +/** + * tee_shm_register_user_buf() - Register a userspace shared memory buffer + * @ctx: Context that registers the shared memory + * @addr: The userspace address of the shared buffer + * @length: Length of the shared buffer + * + * @returns a pointer to 'struct tee_shm' + */ +struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx, + unsigned long addr, size_t length) +{ + u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC; + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + struct iov_iter iter; + void *ret; + int id; + + if (!access_ok((void __user *)addr, length)) + return ERR_PTR(-EFAULT); + + mutex_lock(&teedev->mutex); + id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL); + mutex_unlock(&teedev->mutex); + if (id < 0) + return ERR_PTR(id); + + iov_iter_ubuf(&iter, ITER_DEST, (void __user *)addr, length); + shm = register_shm_helper(ctx, &iter, flags, id); + if (IS_ERR(shm)) { + mutex_lock(&teedev->mutex); + idr_remove(&teedev->idr, id); + mutex_unlock(&teedev->mutex); + return shm; + } + + mutex_lock(&teedev->mutex); + ret = idr_replace(&teedev->idr, shm, id); + mutex_unlock(&teedev->mutex); + if (IS_ERR(ret)) { + tee_shm_free(shm); + return ret; + } + + return shm; +} + +/** + * tee_shm_register_kernel_buf() - Register kernel memory to be shared with + * secure world + * @ctx: Context that registers the shared memory + * @addr: The buffer + * @length: Length of the buffer + * + * @returns a pointer to 'struct tee_shm' + */ + +struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx, + void *addr, size_t length) +{ + u32 flags = TEE_SHM_DYNAMIC; + struct kvec kvec; + struct iov_iter iter; + + kvec.iov_base = addr; + kvec.iov_len = length; + iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length); + + return register_shm_helper(ctx, &iter, flags, -1); +} +EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf); + +static int tee_shm_fop_release(struct inode *inode, struct file *filp) +{ + tee_shm_put(filp->private_data); + return 0; +} + +static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct tee_shm *shm = filp->private_data; + size_t size = vma->vm_end - vma->vm_start; + + /* 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) + return -EINVAL; + + return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT, + size, vma->vm_page_prot); +} + +static const struct file_operations tee_shm_fops = { + .owner = THIS_MODULE, + .release = tee_shm_fop_release, + .mmap = tee_shm_fop_mmap, +}; + +/** + * tee_shm_get_fd() - Increase reference count and return file descriptor + * @shm: Shared memory handle + * @returns user space file descriptor to shared memory + */ +int tee_shm_get_fd(struct tee_shm *shm) +{ + int fd; + + if (shm->id < 0) + return -EINVAL; + + /* matched by tee_shm_put() in tee_shm_op_release() */ + refcount_inc(&shm->refcount); + fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR); + if (fd < 0) + tee_shm_put(shm); + return fd; +} + +/** + * tee_shm_free() - Free shared memory + * @shm: Handle to shared memory to free + */ +void tee_shm_free(struct tee_shm *shm) +{ + tee_shm_put(shm); +} +EXPORT_SYMBOL_GPL(tee_shm_free); + +/** + * tee_shm_get_va() - Get virtual address of a shared memory plus an offset + * @shm: Shared memory handle + * @offs: Offset from start of this shared memory + * @returns virtual address of the shared memory + offs if offs is within + * the bounds of this shared memory, else an ERR_PTR + */ +void *tee_shm_get_va(struct tee_shm *shm, size_t offs) +{ + if (!shm->kaddr) + return ERR_PTR(-EINVAL); + if (offs >= shm->size) + return ERR_PTR(-EINVAL); + return (char *)shm->kaddr + offs; +} +EXPORT_SYMBOL_GPL(tee_shm_get_va); + +/** + * tee_shm_get_pa() - Get physical address of a shared memory plus an offset + * @shm: Shared memory handle + * @offs: Offset from start of this shared memory + * @pa: Physical address to return + * @returns 0 if offs is within the bounds of this shared memory, else an + * error code. + */ +int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa) +{ + if (offs >= shm->size) + return -EINVAL; + if (pa) + *pa = shm->paddr + offs; + return 0; +} +EXPORT_SYMBOL_GPL(tee_shm_get_pa); + +/** + * tee_shm_get_from_id() - Find shared memory object and increase reference + * count + * @ctx: Context owning the shared memory + * @id: Id of shared memory object + * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure + */ +struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id) +{ + struct tee_device *teedev; + struct tee_shm *shm; + + if (!ctx) + return ERR_PTR(-EINVAL); + + teedev = ctx->teedev; + mutex_lock(&teedev->mutex); + shm = idr_find(&teedev->idr, id); + /* + * If the tee_shm was found in the IDR it must have a refcount + * larger than 0 due to the guarantee in tee_shm_put() below. So + * it's safe to use refcount_inc(). + */ + if (!shm || shm->ctx != ctx) + shm = ERR_PTR(-EINVAL); + else + refcount_inc(&shm->refcount); + mutex_unlock(&teedev->mutex); + return shm; +} +EXPORT_SYMBOL_GPL(tee_shm_get_from_id); + +/** + * tee_shm_put() - Decrease reference count on a shared memory handle + * @shm: Shared memory handle + */ +void tee_shm_put(struct tee_shm *shm) +{ + struct tee_device *teedev; + bool do_release = false; + + if (!shm || !shm->ctx || !shm->ctx->teedev) + return; + + teedev = shm->ctx->teedev; + mutex_lock(&teedev->mutex); + if (refcount_dec_and_test(&shm->refcount)) { + /* + * refcount has reached 0, we must now remove it from the + * IDR before releasing the mutex. This will guarantee that + * the refcount_inc() in tee_shm_get_from_id() never starts + * from 0. + */ + if (shm->id >= 0) + idr_remove(&teedev->idr, shm->id); + do_release = true; + } + mutex_unlock(&teedev->mutex); + + if (do_release) + tee_shm_release(teedev, shm); +} +EXPORT_SYMBOL_GPL(tee_shm_put); |