Commit e433715b authored by Oleksandr Tyshchenko's avatar Oleksandr Tyshchenko Committed by Juergen Gross
Browse files

xen/virtio: Fix n_pages calculation in xen_grant_dma_map(unmap)_page() 



Take page offset into the account when calculating the number of pages
to be granted.

Fixes: d6aca350 ("xen/grant-dma-ops: Add option to restrict memory access under Xen")
Signed-off-by: default avatarOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: default avatarStefano Stabellini <sstabellini@kernel.org>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221005174823.1800761-2-olekstysh@gmail.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 06c62f8c

drivers/xen/grant-dma-ops.c

+3 −2
Original line number Diff line number Diff line
@@ -153,7 +153,7 @@ static dma_addr_t xen_grant_dma_map_page(struct device *dev, struct page *page, 
					 unsigned long attrs)

{

	struct xen_grant_dma_data *data;

	unsigned int i, n_pages = PFN_UP(size);

	unsigned int i, n_pages = PFN_UP(offset + size);

	grant_ref_t grant;

	dma_addr_t dma_handle;
@@ -185,7 +185,8 @@ static void xen_grant_dma_unmap_page(struct device *dev, dma_addr_t dma_handle, 
				     unsigned long attrs)

{

	struct xen_grant_dma_data *data;

	unsigned int i, n_pages = PFN_UP(size);

	unsigned long offset = dma_handle & (PAGE_SIZE - 1);

	unsigned int i, n_pages = PFN_UP(offset + size);

	grant_ref_t grant;



	if (WARN_ON(dir == DMA_NONE))