From 1a87228f5f1d316002c7c161316f5524592be766 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 12 Apr 2012 15:36:34 +1000 Subject: virtio_balloon: Fix endian bug 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 Signed-off-by: Michael S. Tsirkin --- 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 05f0a80818a2..9e95ca602006 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -234,11 +234,14 @@ 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) -- cgit v1.2.3-59-g8ed1b