[PATCH 3/4] virtio: handle > 2 billion page balloon targets

Rusty Russell
2008-03-11T12:07:42Z

If the host asks for a huge target towards_target() can overflow, and
we up oops as we try to release more pages than we have. The simple
fix is to use a 64-bit value.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
drivers/virtio/virtio_balloon.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff -r fd0c80dbbd95 drivers/virtio/virtio_balloon.c
--- a/drivers/virtio/virtio_balloon.c Tue Mar 11 09:21:00 2008 +1100
+++ b/drivers/virtio/virtio_balloon.c Tue Mar 11 11:25:52 2008 +1100
@@ -152,7 +152,7 @@ static void virtballoon_changed(struct v
wake_up(&vb->config_change);
}

-static inline int towards_target(struct virtio_balloon *vb)
+static inline s64 towards_target(struct virtio_balloon *vb)
{
u32 v;
__virtio_config_val(vb->vdev,
@@ -176,7 +183,7 @@ static int balloon(void *_vballoon)

set_freezable();
while (!kthread_should_stop()) {
- int diff;
+ s64 diff;

try_to_freeze();
wait_event_interruptible(vb->config_change,