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authorOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>2022-10-05 20:48:22 +0300
committerJuergen Gross <jgross@suse.com>2022-10-06 08:30:10 +0200
commite433715b116553892ecad8796018ae4b64304252 (patch)
tree3d8c3bdd5cf6febdb50de5b755b30177eb0b0295 /drivers/xen
parent06c62f8cbb1f660a4147b0d8cbe65cf2cfc1aa5a (diff)
downloadlinux-e433715b116553892ecad8796018ae4b64304252.tar.gz
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: d6aca3504c7d ("xen/grant-dma-ops: Add option to restrict memory access under Xen") Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20221005174823.1800761-2-olekstysh@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/grant-dma-ops.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
index 8973fc1e9cccd..1998d0e8ce82a 100644
--- a/drivers/xen/grant-dma-ops.c
+++ b/drivers/xen/grant-dma-ops.c
@@ -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))