xen/gntdev: Check and release imported dma-bufs on close

Check if there are any imported dma-bufs left not released by
user-space when grant device's release callback is called and
free those if this is the case. This can happen if user-space
leaks the buffers because of a bug or application has been
terminated for any reason.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c
index d97fcfc5e558..2c4f324f8626 100644
--- a/drivers/xen/gntdev-dmabuf.c
+++ b/drivers/xen/gntdev-dmabuf.c
@@ -745,6 +745,14 @@ static int dmabuf_imp_release(struct gntdev_dmabuf_priv *priv, u32 fd)
         return 0;
 }
 
+static void dmabuf_imp_release_all(struct gntdev_dmabuf_priv *priv)
+{
+        struct gntdev_dmabuf *q, *gntdev_dmabuf;
+
+        list_for_each_entry_safe(gntdev_dmabuf, q, &priv->imp_list, next)
+                dmabuf_imp_release(priv, gntdev_dmabuf->fd);
+}
+
 /* DMA buffer IOCTL support. */
 
 long gntdev_ioctl_dmabuf_exp_from_refs(struct gntdev_priv *priv, int use_ptemod,
@@ -862,5 +870,6 @@ struct gntdev_dmabuf_priv *gntdev_dmabuf_init(struct file *filp)
 
 void gntdev_dmabuf_fini(struct gntdev_dmabuf_priv *priv)
 {
+        dmabuf_imp_release_all(priv);
         kfree(priv);
 }