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-rw-r--r--drivers/tee/tee_shm.c529
1 files changed, 529 insertions, 0 deletions
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
new file mode 100644
index 000000000..27295bda3
--- /dev/null
+++ b/drivers/tee/tee_shm.c
@@ -0,0 +1,529 @@
+// 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/idr.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/tee_drv.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+#include "tee_private.h"
+
+static void shm_put_kernel_pages(struct page **pages, size_t page_count)
+{
+ size_t n;
+
+ for (n = 0; n < page_count; n++)
+ put_page(pages[n]);
+}
+
+static int shm_get_kernel_pages(unsigned long start, size_t page_count,
+ struct page **pages)
+{
+ size_t n;
+ int rc;
+
+ if (is_vmalloc_addr((void *)start)) {
+ struct page *page;
+
+ for (n = 0; n < page_count; n++) {
+ page = vmalloc_to_page((void *)(start + PAGE_SIZE * n));
+ if (!page)
+ return -ENOMEM;
+
+ get_page(page);
+ pages[n] = page;
+ }
+ rc = page_count;
+ } else {
+ struct kvec *kiov;
+
+ kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
+ if (!kiov)
+ return -ENOMEM;
+
+ for (n = 0; n < page_count; n++) {
+ kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
+ kiov[n].iov_len = PAGE_SIZE;
+ }
+
+ rc = get_kernel_pages(kiov, page_count, 0, pages);
+ kfree(kiov);
+ }
+
+ return rc;
+}
+
+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);
+ else
+ shm_put_kernel_pages(shm->pages, shm->num_pages);
+
+ kfree(shm->pages);
+ }
+}
+
+static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
+{
+ 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(shm);
+
+ 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(sizeof(*shm), GFP_KERNEL);
+ 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'
+ */
+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);
+
+/**
+ * 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);
+
+static struct tee_shm *
+register_shm_helper(struct tee_context *ctx, unsigned long addr,
+ size_t length, u32 flags, int id)
+{
+ struct tee_device *teedev = ctx->teedev;
+ struct tee_shm *shm;
+ unsigned long start;
+ size_t num_pages;
+ 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(sizeof(*shm), GFP_KERNEL);
+ 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(addr);
+ start = rounddown(addr, PAGE_SIZE);
+ shm->offset = addr - start;
+ shm->size = length;
+ num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
+ shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
+ if (!shm->pages) {
+ ret = ERR_PTR(-ENOMEM);
+ goto err_free_shm;
+ }
+
+ if (flags & TEE_SHM_USER_MAPPED)
+ rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
+ shm->pages);
+ else
+ rc = shm_get_kernel_pages(start, num_pages, shm->pages);
+ if (rc > 0)
+ shm->num_pages = rc;
+ if (rc != num_pages) {
+ if (rc >= 0)
+ rc = -ENOMEM;
+ ret = ERR_PTR(rc);
+ goto err_put_shm_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 (flags & TEE_SHM_USER_MAPPED)
+ unpin_user_pages(shm->pages, shm->num_pages);
+ else
+ shm_put_kernel_pages(shm->pages, shm->num_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;
+ 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);
+
+ shm = register_shm_helper(ctx, addr, length, 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;
+
+ return register_shm_helper(ctx, (unsigned long)addr, length, 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;
+
+ /* 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 = shm->ctx->teedev;
+ bool do_release = false;
+
+ 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);