Commit 7bdee415 authored by Arnaud Pouliquen's avatar Arnaud Pouliquen Committed by Jens Wiklander
Browse files

tee: Use iov_iter to better support shared buffer registration 



Currently it's not possible to register kernel buffers with TEE
which are allocated via vmalloc.

Use iov_iter and associated helper functions to manage the page
registration for all type of memories.

Suggested-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarArnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: default avatarSumit Garg <sumit.garg@linaro.org>
Signed-off-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
parent b85ea95d

drivers/tee/tee_shm.c

+42 −36
Original line number Diff line number Diff line
@@ -22,25 +22,14 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count) 
		put_page(pages[n]);

}



static int shm_get_kernel_pages(unsigned long start, size_t page_count,

				struct page **pages)

static void shm_get_kernel_pages(struct page **pages, size_t page_count)

{

	struct page *page;

	size_t n;



	if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||

			 is_kmap_addr((void *)start)))

		return -EINVAL;



	page = virt_to_page((void *)start);

	for (n = 0; n < page_count; n++) {

		pages[n] = page + n;

	for (n = 0; n < page_count; n++)

		get_page(pages[n]);

}



	return page_count;

}



static void release_registered_pages(struct tee_shm *shm)

{

	if (shm->pages) {
@@ -214,13 +203,14 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) 
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)

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;

	size_t num_pages;

	unsigned long start, addr;

	size_t num_pages, off;

	ssize_t len;

	void *ret;

	int rc;
@@ -245,31 +235,38 @@ register_shm_helper(struct tee_context *ctx, unsigned long addr, 
	shm->flags = flags;

	shm->ctx = ctx;

	shm->id = id;

	addr = untagged_addr(addr);

	addr = untagged_addr((unsigned long)iter_iov_addr(iter));

	start = rounddown(addr, PAGE_SIZE);

	shm->offset = addr - start;

	shm->size = length;

	num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;

	num_pages = iov_iter_npages(iter, INT_MAX);

	if (!num_pages) {

		ret = ERR_PTR(-ENOMEM);

		goto err_ctx_put;

	}



	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;

	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;

	}



	/*

	 * iov_iter_extract_kvec_pages does not get reference on the pages,

	 * get a reference on them.

	 */

	if (iov_iter_is_kvec(iter))

		shm_get_kernel_pages(shm->pages, num_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) {
@@ -279,10 +276,11 @@ register_shm_helper(struct tee_context *ctx, unsigned long addr, 


	return shm;

err_put_shm_pages:

	if (flags & TEE_SHM_USER_MAPPED)

	if (!iov_iter_is_kvec(iter))

		unpin_user_pages(shm->pages, shm->num_pages);

	else

		shm_put_kernel_pages(shm->pages, shm->num_pages);

err_free_shm_pages:

	kfree(shm->pages);

err_free_shm:

	kfree(shm);
@@ -307,6 +305,7 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx, 
	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;
@@ -319,7 +318,8 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx, 
	if (id < 0)

		return ERR_PTR(id);



	shm = register_shm_helper(ctx, addr, length, flags, 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);
@@ -352,8 +352,14 @@ 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, (unsigned long)addr, length, flags, -1);

	return register_shm_helper(ctx, &iter, flags, -1);

}

EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);