Messages in this thread Patch in this message |  | | | From | David Gibson <> | | Subject | [PATCH 2/3] virtio_balloon: Fix endian bug | | Date | Thu, 12 Apr 2012 15:36:34 +1000 |
| |
Although virtio config space fields are usually in guest-native endian, the spec for the virtio balloon device explicitly states that both fields in its config space are little-endian.
However, the current virtio_balloon driver does not have a suitable endian swap for the 'num_pages' field, although it does have one for the 'actual' field. This patch corrects the bug, adding sparse annotation while we're at it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au> --- drivers/virtio/virtio_balloon.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 6c07793..553cc1f 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -238,11 +238,14 @@ static void virtballoon_changed(struct virtio_device *vdev) static inline s64 towards_target(struct virtio_balloon *vb) { - u32 v; + __le32 v; + s64 target; + vb->vdev->config->get(vb->vdev, offsetof(struct virtio_balloon_config, num_pages), &v, sizeof(v)); - return (s64)v - vb->num_pages; + target = le32_to_cpu(v); + return target - vb->num_pages; } static void update_balloon_size(struct virtio_balloon *vb) -- 1.7.9.5
|  |