xen/gntdev: Fix partial gntdev_mmap() cleanup

When cleaning up after a partially successful gntdev_mmap(), unmap the
successfully mapped grant pages otherwise Xen will kill the domain if
in debug mode (Attempt to implicitly unmap a granted PTE) or Linux will
kill the process and emit "BUG: Bad page map in process" if Xen is in
release mode.

This is only needed when use_ptemod is true because gntdev_put_map()
will unmap grant pages itself when use_ptemod is false.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
This commit is contained in:
Ross Lagerwall 2018-01-09 12:10:22 +00:00 committed by Boris Ostrovsky
parent 951a010233
commit cf2acf66ad

View File

@ -1071,8 +1071,10 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
out_unlock_put:
mutex_unlock(&priv->lock);
out_put_map:
if (use_ptemod)
if (use_ptemod) {
map->vma = NULL;
unmap_grant_pages(map, 0, map->count);
}
gntdev_put_map(priv, map);
return err;
}